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Wang H, Zheng A, Thorley D, Arias EB, Cartee GD. Independent and combined effects of calorie restriction and AICAR on glucose uptake and insulin signaling in skeletal muscles from 24-month-old female and male rats. Appl Physiol Nutr Metab 2024; 49:614-625. [PMID: 38181403 DOI: 10.1139/apnm-2023-0522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2024]
Abstract
We assessed the effects of two levels of calorie restriction (CR; eating either 15% or 35% less than ad libitum, AL, food intake for 8 weeks) by 24-month-old female and male rats on glucose uptake (GU) and phosphorylation of key signaling proteins (Akt; AMP-activated protein kinase, AMPK; Akt substrate of 160 kDa, AS160) measured in isolated skeletal muscles that underwent four incubation conditions (without either insulin or AICAR, an AMPK activator; with AICAR alone; with insulin alone; or with insulin and AICAR). Regardless of sex: (1) neither CR group versus the AL group had greater GU by insulin-stimulated muscles; (2) phosphorylation of Akt in insulin-stimulated muscles was increased in 35% CR versus AL rats; (3) prior AICAR treatment of muscle resulted in greater GU by insulin-stimulated muscles, regardless of diet; and (4) AICAR caused elevated phosphorylation of acetyl CoA carboxylase, an indicator of AMPK activation, in all diet groups. There was a sexually dimorphic diet effect on AS160 phosphorylation, with 35% CR exceeding AL for insulin-stimulated muscles in male rats, but not in female rats. Our working hypothesis is that the lack of a CR-effect on GU by insulin-stimulated muscles was related to the extended duration of the ex vivo incubation period (290 min compared to 40-50 min that was previously reported to be effective). The observed efficacy of prior treatment of muscles with AICAR to improve glucose uptake in insulin-stimulated muscles supports the strategy of targeting AMPK with the goal of improving insulin sensitivity in older females and males.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Amy Zheng
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Dominic Thorley
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Edward B Arias
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Gregory D Cartee
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- Institute of Gerontology, University of Michigan, Ann Arbor, MI, USA
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Zyoud SH. Mapping the landscape of research on insulin resistance: a visualization analysis of randomized clinical trials. JOURNAL OF HEALTH, POPULATION, AND NUTRITION 2024; 43:6. [PMID: 38195616 PMCID: PMC10777523 DOI: 10.1186/s41043-024-00497-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 01/05/2024] [Indexed: 01/11/2024]
Abstract
BACKGROUND Insulin resistance, a condition in which cells do not respond adequately to insulin, plays a crucial role in diabetes and related metabolic disorders. Randomized clinical trials (RCTs) explore interventions to manage insulin resistance, contributing to evidence-based medical progress. The current study aimed to analyze the global research landscape and trends in RCTs targeting insulin resistance. METHODS This study used bibliometric analysis and data visualization to examine RCT publications on insulin resistance from 2003 to 2022. The Scopus database was used due to its comprehensive coverage. The search strategy involved combining terms related to insulin resistance with RCT-related terms. The search query was validated, and core bibliometric indicators were used to analyze publication growth, origin, productivity, quality, and citations. RESULTS Between 2003 and 2022, 1077 RCT-focused publications on insulin resistance were identified from a pool of 24,932 related articles. The growth followed two phases, with a significant increase after 2008. The USA (n = 308; 28.60%), Iran (n = 165; 15.32%), China (n = 110; 10.21%), and the UK (n = 92; 8.54%) were the main contributors. The active institutions included Tehran University of Medical Sciences (n = 38; 3.53%) and Harvard Medical School (n = 31; 2.88%). Prominent funding agencies include the National Institutes of Health (n = 88; 8.17%) and the National Institute of Diabetes and Digestive and Kidney Diseases (n = 86; 7.99%). The top journals included the American Journal of Clinical Nutrition (n = 44; 4.09%) and Diabetes Care (n = 35; 3.25%). Co-occurrence analysis revealed three clusters addressing "utilizing lipid panels as indicators of insulin resistance," "analyzing the impact of diet composition and physical activity on insulin sensitivity among obese individuals," and "exploring insulin resistance in cases of polycystic ovary syndrome." CONCLUSIONS This comprehensive bibliometric analysis highlights the global research landscape and trends in RCTs targeting insulin resistance. Research on lipid panels, diet impact, and insulin resistance in patients with polycystic ovary syndrome will continue to be a hotspot. The findings offer valuable information on research priorities, international collaborations, and impactful publications. This study provides a foundation for future directorial investigations in this critical area of metabolic health.
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Affiliation(s)
- Sa'ed H Zyoud
- Department of Clinical and Community Pharmacy, College of Medicine and Health Sciences, An-Najah National University, Nablus, 44839, Palestine.
- Clinical Research Centre, An-Najah National University Hospital, Nablus, 44839, Palestine.
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Rundle M, Fiamoncini J, Thomas EL, Wopereis S, Afman LA, Brennan L, Drevon CA, Gundersen TE, Daniel H, Perez IG, Posma JM, Ivanova DG, Bell JD, van Ommen B, Frost G. Diet-induced Weight Loss and Phenotypic Flexibility Among Healthy Overweight Adults: A Randomized Trial. Am J Clin Nutr 2023; 118:591-604. [PMID: 37661105 PMCID: PMC10517213 DOI: 10.1016/j.ajcnut.2023.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 09/05/2023] Open
Abstract
BACKGROUND The capacity of an individual to respond to changes in food intake so that postprandial metabolic perturbations are resolved, and metabolism returns to its pre-prandial state, is called phenotypic flexibility. This ability may be a more important indicator of current health status than metabolic markers in a fasting state. AIM In this parallel randomized controlled trial study, an energy-restricted healthy diet and 2 dietary challenges were used to assess the effect of weight loss on phenotypic flexibility. METHODS Seventy-two volunteers with overweight and obesity underwent a 12-wk dietary intervention. The participants were randomized to a weight loss group (WLG) with 20% less energy intake or a weight-maintenance group (WMG). At weeks 1 and 12, participants were assessed for body composition by MRI. Concurrently, markers of metabolism and insulin sensitivity were obtained from the analysis of plasma metabolome during 2 different dietary challenges-an oral glucose tolerance test (OGTT) and a mixed-meal tolerance test. RESULTS Intended weight loss was achieved in the WLG (-5.6 kg, P < 0.0001) and induced a significant reduction in total and regional adipose tissue as well as ectopic fat in the liver. Amino acid-based markers of insulin action and resistance such as leucine and glutamate were reduced in the postprandial phase of the OGTT in the WLG by 11.5% and 28%, respectively, after body weight reduction. Weight loss correlated with the magnitude of changes in metabolic responses to dietary challenges. Large interindividual variation in metabolic responses to weight loss was observed. CONCLUSION Application of dietary challenges increased sensitivity to detect metabolic response to weight loss intervention. Large interindividual variation was observed across a wide range of measurements allowing the identification of distinct responses to the weight loss intervention and mechanistic insight into the metabolic response to weight loss.
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Affiliation(s)
- Milena Rundle
- Section of Nutrition, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Jarlei Fiamoncini
- Food Research Center, Department of Food Science and Experimental Nutrition, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - E Louise Thomas
- Research Centre for Optimal Health, School of Life Sciences, University of Westminster, London, United Kingdom
| | - Suzan Wopereis
- Department of Microbiology and Systems Biology, Netherlands Organization for Applied Scientific Research, Hague, The Netherlands
| | - Lydia A Afman
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Lorraine Brennan
- UCD School of Agriculture and Food Science, Institute of Food and Health, University College Dublin, Belfield, Dublin, Ireland
| | - Christian A Drevon
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; Vitas Ltd, Oslo Science Park, Oslo, Norway
| | | | - Hannelore Daniel
- Hannelore Daniel, Molecular Nutrition Unit, Technische Universität München, München, Germany
| | - Isabel Garcia Perez
- Section of Nutrition, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Joram M Posma
- Section of Bioinformatics, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Diana G Ivanova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Faculty of Pharmacy, Medical University, Varna, Bulgaria
| | - Jimmy D Bell
- Research Centre for Optimal Health, School of Life Sciences, University of Westminster, London, United Kingdom
| | - Ben van Ommen
- Department of Microbiology and Systems Biology, Netherlands Organization for Applied Scientific Research, Hague, The Netherlands
| | - Gary Frost
- Section of Nutrition, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom.
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Kakehi S, Tamura Y, Ikeda SI, Kaga N, Taka H, Nishida Y, Kawamori R, Watada H. Physical inactivity induces insulin resistance in plantaris muscle through protein tyrosine phosphatase 1B activation in mice. Front Physiol 2023; 14:1198390. [PMID: 37389126 PMCID: PMC10300557 DOI: 10.3389/fphys.2023.1198390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/05/2023] [Indexed: 07/01/2023] Open
Abstract
Inactivity causes insulin resistance in skeletal muscle and exacerbates various lifestyle-related diseases. We previously found that 24-h hindlimb cast immobilization (HCI) of the predominantly slow-twitch soleus muscle increased intramyocellular diacylglycerol (IMDG) and insulin resistance by activation of lipin1, and HCI after a high-fat diet (HFD) further aggravated insulin resistance. Here, we investigated the effects of HCI on the fast-twitch-predominant plantaris muscle. HCI reduced the insulin sensitivity of plantaris muscle by approximately 30%, and HCI following HFD dramatically reduced insulin sensitivity by approximately 70% without significant changes in the amount of IMDG. Insulin-stimulated phosphorylation levels of insulin receptor (IR), IR substrate-1, and Akt were reduced in parallel with the decrease in insulin sensitivity. Furthermore, tyrosine phosphatase 1B (PTP1B), a protein known to inhibit insulin action by dephosphorylating IR, was activated, and PTP1B inhibition canceled HCI-induced insulin resistance. In conclusion, HCI causes insulin resistance in the fast-twitch-predominant plantaris muscle as well as in the slow-twitch-predominant soleus muscle, and HFD potentiates these effects in both muscle types. However, the mechanism differed between soleus and plantaris muscles, since insulin resistance was mediated by the PTP1B inhibition at IR in plantaris muscle.
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Affiliation(s)
- Saori Kakehi
- Department of Metabolism and Endocrinology, Tokyo, Japan
- Sportology Center, Tokyo, Japan
| | - Yoshifumi Tamura
- Department of Metabolism and Endocrinology, Tokyo, Japan
- Sportology Center, Tokyo, Japan
| | - Shin-ichi Ikeda
- Department of Metabolism and Endocrinology, Tokyo, Japan
- Sportology Center, Tokyo, Japan
| | - Naoko Kaga
- Division of Proteomics and Biomolecular Science, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hikari Taka
- Division of Proteomics and Biomolecular Science, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yuya Nishida
- Department of Metabolism and Endocrinology, Tokyo, Japan
| | - Ryuzo Kawamori
- Department of Metabolism and Endocrinology, Tokyo, Japan
- Sportology Center, Tokyo, Japan
| | - Hirotaka Watada
- Department of Metabolism and Endocrinology, Tokyo, Japan
- Sportology Center, Tokyo, Japan
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Pérez-Rodríguez M, Huertas JR, Villalba JM, Casuso RA. Mitochondrial adaptations to calorie restriction and bariatric surgery in human skeletal muscle: a systematic review with meta-analysis. Metabolism 2023; 138:155336. [PMID: 36302454 DOI: 10.1016/j.metabol.2022.155336] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/11/2022] [Accepted: 10/17/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We performed a meta-analysis to determine the changes induced by calorie restriction (CR) and bariatric surgery on human skeletal muscle mitochondria. METHODS A systematic search of Medline and Web of Science was conducted. Controlled trials exploring CR (≥14 days) and mitochondrial function and/or content assessment were included. Moreover, studies analyzing weight loss following gastric surgery were included for comparison purposes. Human muscle data from 28 studies assessing CR (520 muscle samples) and from 10 studies assessing bariatric surgery (155 muscle samples) were analyzed in a random effect meta-analysis with three a priori chosen covariates. MAIN RESULTS We report a decrease (p < 0.05) (mean (95 % CI)) in maximal mitochondrial state 3 respiration in response to CR (-0.44 (-0.85, -0.03)) but not in response to surgery (-0.33 (-1.18, 0.52)). No changes in mitochondrial content were reported after CR (-0.05 (-0.12, 0.13)) or in response to surgery (0.23 (-0.05, 0.52)). Moreover, data from CR subjects showed a reduction in complex IV (CIV) activity (-0.29 (-0.56, -0.03)) but not in CIV content (-0.21 (-0.63, 0.22)). Similar results were obtained when the length of the protocol, the initial body mass index, and the estimated energy deficit were included in the model as covariates. CONCLUSION The observation of reduced maximal mitochondrial state 3, uncoupled respiration, and CIV activity without altering mitochondrial content suggests that, in human skeletal muscle, CR mainly modulates intrinsic mitochondrial function.
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Affiliation(s)
- Miguel Pérez-Rodríguez
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, and ceiA3Campus of International Excellence in Agrifood, Spain
| | | | - José M Villalba
- Department of Cell Biology, Physiology and Immunology, University of Córdoba, and ceiA3Campus of International Excellence in Agrifood, Spain
| | - Rafael A Casuso
- Department of Physiology, University of Granada, Spain; Department of Health Sciences, Universidad Loyola Andalucía, Spain.
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Deb S, Bhandary S, Sinha SK, Jolly MK, Dutta PS. Identifying critical transitions in complex diseases. J Biosci 2022. [PMID: 36210727 PMCID: PMC9018973 DOI: 10.1007/s12038-022-00258-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Veit M, van Asten R, Olie A, Prinz P. The role of dietary sugars, overweight, and obesity in type 2 diabetes mellitus: a narrative review. Eur J Clin Nutr 2022; 76:1497-1501. [PMID: 35314768 PMCID: PMC9630103 DOI: 10.1038/s41430-022-01114-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/18/2022] [Accepted: 02/25/2022] [Indexed: 01/17/2023]
Abstract
Nowadays, there is still a popular belief that dietary sugars, in particular sucrose, are directly linked to the development of type 2 diabetes mellitus (T2DM). Furthermore, since insulin action is impaired in T2DM, it is still believed that excluding dietary sugars from the diet can adequately treat T2DM. This might be based on the assumption that dietary sugars have a stronger impact on blood glucose levels than other carbohydrates. Therefore, the aim of this review is to discuss the effects of dietary sugars intake, including sugar-sweetened beverages (SSBs) against the background of overall energy intake and weight gain in the development of T2DM. Furthermore, the effect of dietary sugars, including SSBs on glycemic control will be discussed. Results from various systematic reviews and meta-analyses do not support the idea that the intake of sucrose and other dietary sugars is linked to T2DM. Long-chain or complex carbohydrates can have a greater impact on postprandial glycemic response than sucrose. SSBs do not affect glycemic control if substituted for other calorie sources. Current scientific evidence clearly points toward excess energy intake followed by excess body fat gain being most relevant in the development of T2DM.
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Affiliation(s)
- Meike Veit
- Department Consumer Protection-Nutrition Policy-Sustainability Europe, Pfeifer & Langen GmbH & Co. KG, Cologne, Germany
| | | | - Andries Olie
- Board Members, Knowledge Centre Sugar & Nutrition, Hilversum, The Netherlands.,Royal Cosun, Breda, The Netherlands
| | - Philip Prinz
- Department of Nutritional Sciences, German Sugar Association, Berlin, Germany.
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Mthembu SXH, Mazibuko-Mbeje SE, Ziqubu K, Nyawo TA, Obonye N, Nyambuya TM, Nkambule BB, Silvestri S, Tiano L, Muller CJF, Dludla PV. Impact of physical exercise and caloric restriction in patients with type 2 diabetes: Skeletal muscle insulin resistance and mitochondrial dysfunction as ideal therapeutic targets. Life Sci 2022; 297:120467. [PMID: 35271881 DOI: 10.1016/j.lfs.2022.120467] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 01/01/2023]
Abstract
Skeletal muscle insulin resistance and mitochondrial dysfunction are some of the major pathological defects implicated in the development of type 2 diabetes (T2D). Therefore, it has become necessary to understand how common interventions such as physical exercise and caloric restriction affect metabolic function, including physiological processes that implicate skeletal muscle dysfunction within a state of T2D. This review critically discusses evidence on the impact of physical exercise and caloric restriction on markers of insulin resistance and mitochondrial dysfunction within the skeletal muscle of patients with T2D or related metabolic complications. Importantly, relevant information from clinical studies was acquired through a systematic approach targeting major electronic databases and search engines such as PubMed, Google Scholar, and Cochrane library. The reported evidence suggests that interventions like physical exercise and caloric restriction, within a duration of approximately 2 to 4 months, can improve insulin sensitivity, in part by targeting the phosphoinositide 3-kinases/protein kinase B pathway in patients with T2D. Furthermore, both physical exercise and caloric restriction can effectively modulate markers related to improved mitochondrial function and dynamics. This was consistent with an improved modulation of mitochondrial oxidative capacity and reduced production of reactive oxygen species in patients with T2D or related metabolic complications. However, such conclusions are based on limited evidence, additional clinical trials are required to better understand these interventions on pathological mechanisms of T2D and related abnormalities.
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Affiliation(s)
- Sinenhlanhla X H Mthembu
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho 2735, South Africa
| | | | - Khanyisani Ziqubu
- Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho 2735, South Africa
| | - Thembeka A Nyawo
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Nnini Obonye
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Tawanda M Nyambuya
- Department of Health Sciences, Faculty of Health and Applied Sciences, Namibia University of Science and Technology, Windhoek 9000, Namibia
| | - Bongani B Nkambule
- School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu Natal, Durban 4000, South Africa
| | - Sonia Silvestri
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona 60131, Italy
| | - Luca Tiano
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona 60131, Italy
| | - Christo J F Muller
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa; Centre for Cardiometabolic Research Africa (CARMA), Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa; Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3880, South Africa
| | - Phiwayinkosi V Dludla
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg 7505, South Africa.
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Sibiya N, Mbatha B, Arineitwe C, Onyekwuluje C, Ngubane P, Khathi A. Covid 19 May Limit the Use of Anti-hyperglycemic Agents. Does it Call for the Development of New Anti-hyperglycemic Agents? Curr Diabetes Rev 2022; 18:e060821195364. [PMID: 34365928 DOI: 10.2174/1573399817666210806114200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/10/2021] [Accepted: 06/15/2021] [Indexed: 01/08/2023]
Abstract
Diabetes mellitus has been identified as a major risk factor for developing severe COVID 19 complications. In this review article, the efforts were directed to provide insights and the possible extent to which some diabetic pharmacological interventions may exacerbate COVID 19 or may not be idyllic options for COVID 19 patients. Articles reviewed were identified using the Google scholar database, and search was done using the English language. Anti-hyperglycemic is associated with undesirable effects including episodes of hypoglycemia, diarrhea, lactic acidosis, and increased risks of cardiovascular and hepatic hazards. These undesirable effects associated with the anti-hyperglycemic agents possess a threat of developing severe COVID19 complications Therefore, this calls for more studies to understand the extent of the risks these agents possess in diabetic COVID 19 patients. Almost all the anti-hyperglycemic agents have the potential to worsen COVID 19, despite their class. COVID 19 may limit the options in terms of available anti-hyperglycemic agents which may not heighten the risk of developing severe COVID 19 complications. The research towards the discovery and development of new compounds and also new therapeutic targets for hyperglycemia should be encouraged and welcome.
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Affiliation(s)
- Ntethelelo Sibiya
- Pharmacology Division, Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa
| | - Bonisiwe Mbatha
- School of Laboratory Medicine, College of Health Science, University of KwaZulu-Natal, Durban, South Africa
| | - Charles Arineitwe
- Pharmacology Division, Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa
| | - Chiamaka Onyekwuluje
- Pharmacology Division, Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa
| | - Phikelelani Ngubane
- School of Laboratory Medicine, College of Health Science, University of KwaZulu-Natal, Durban, South Africa
| | - Andile Khathi
- School of Laboratory Medicine, College of Health Science, University of KwaZulu-Natal, Durban, South Africa
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Abdul-Ghani M, DeFronzo RA. Personalized approach for type 2 diabetes pharmacotherapy: where are we and where do we need to be? Expert Opin Pharmacother 2021; 22:2113-2125. [PMID: 34435523 DOI: 10.1080/14656566.2021.1967319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Cluster analysis has identified distinct groups of type 2 diabetes (T2D) subjects with distinct metabolic characteristics. Thus, personalizing pharmacologic therapy to individual phenotypic and pathophysiologic characteristics has potential to improve metabolic control and reduce risk of microvascular and macrovascular complications. AREAS COVERED The authors review the classification of T2D, genetic markers, pathophysiology and natural history of T2D, the ABCDE approach to therapy, the ADA/EASD stepwise approach to therapy, available antidiabetic agents, and provide a more rational therapeutic approach based upon pathophysiology and cardiovascular and renal outcome trials. EXPERT OPINION Although insulin resistance is the earliest detectable abnormality, overt T2D does not occur in the absence of progressive beta cell failure. Because of the complex etiology of T2D (Ominous Octet), initiation of therapy with combined agents that (i) target both insulin resistance and beta cell dysfunction and (ii) prevent macrovascular, as well as microvascular, complications will be required. The ratio of C-peptide at 120 minutes (OGTT) to baseline C-peptide predicts with high sensitivity who will respond to metformin, the response to glucose-lowering agents and provides a useful tool to guide optimal glucose lowering therapy.
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Nonaka Y, Takeda R, Kano Y, Hoshino D. Short-Term Calorie Restriction Maintains Plasma Insulin Concentrations along with a Reduction in Hepatic Insulin-Degrading Enzyme Levels in db/db Mice. Nutrients 2021; 13:nu13041190. [PMID: 33916828 PMCID: PMC8065522 DOI: 10.3390/nu13041190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 12/11/2022] Open
Abstract
Maintaining blood insulin levels is important for patients with diabetes because insulin secretion capacity declines with the development of the disease. Calorie restriction (CR) is effective for the improvement of glucose tolerance, but it is not clear whether CR can maintain insulin levels in the late stage of diabetes. We examined the effect of CR on whole-body glucose tolerance and fasting blood insulin concentrations in the late stage of diabetes. Male db/db mice were subjected to either a standard laboratory diet ad libitum for 3 weeks (dbdb group) or 40% CR (dbdb+CR group). CR significantly decreased body mass and epididymal fat weight. Glucose tolerance and fasting glucose levels were significantly improved with 3-week CR. Fasting insulin concentrations were decreased in the dbdb group but were maintained in the dbdb+CR group. CR significantly reduced insulin-degrading enzyme (IDE) levels in the liver, and hepatic IDE levels were significantly positively and negatively correlated with plasma glucose concentrations (area under the curve) after glucose administration and after fasting insulin concentrations, respectively. Therefore, 3-week CR maintained blood insulin levels and improved glucose tolerance with decreased hepatic IDE levels in an animal model of late-stage diabetes.
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Affiliation(s)
- Yudai Nonaka
- Bioscience and Technology Program, Department of Engineering Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan; (R.T.); (Y.K.); (D.H.)
- Japan Society for the Promotion of Science (JSPS), Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan
- Correspondence: ; Tel.: +81-42-443-5589
| | - Reo Takeda
- Bioscience and Technology Program, Department of Engineering Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan; (R.T.); (Y.K.); (D.H.)
| | - Yutaka Kano
- Bioscience and Technology Program, Department of Engineering Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan; (R.T.); (Y.K.); (D.H.)
| | - Daisuke Hoshino
- Bioscience and Technology Program, Department of Engineering Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan; (R.T.); (Y.K.); (D.H.)
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Cigarette smoking blocks the benefit from reduced weight gain for insulin action by shifting lipids deposition to muscle. Clin Sci (Lond) 2021; 134:1659-1673. [PMID: 32573727 DOI: 10.1042/cs20200173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/10/2020] [Accepted: 06/23/2020] [Indexed: 12/29/2022]
Abstract
Cigarette smoking (CS) is known to reduce body weight and this often masks its real effect on insulin action. The present study tested the hypothesis that CS can divert lipid deposition to muscles to offset the supposed benefit of reduced body weight gain on insulin signalling in this major site for glucose tolerance (or insulin action). The study was conducted in mice exposed to chronic CS followed by either a chow (CH) diet or a high-fat (HF) diet. CS increased triglyceride (TG) levels in both plasma and muscle despite a reduced body weight gain and adiposity. CS led to glucose intolerance in CH-fed mice and they retained the glucose intolerance that was induced by the HF diet. In adipose tissue, CS increased macrophage infiltration and the mRNA expression of TNFα but suppressed the protein expression of adipose triglyceride lipase and PPARγ. While CS increased hormone-sensitive lipase and suppressed the mRNA expression of leptin, these effects were blunted in HF-fed mice. These results imply that CS impairs insulin signalling in skeletal muscle via accumulated intramuscular lipids from lipolysis and lipodystrophy of adipose tissues. This may explain why smokers may not benefit from insulin sensitising effects of reduced body weight gain.
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Kahleova H, Petersen KF, Shulman GI, Alwarith J, Rembert E, Tura A, Hill M, Holubkov R, Barnard ND. Effect of a Low-Fat Vegan Diet on Body Weight, Insulin Sensitivity, Postprandial Metabolism, and Intramyocellular and Hepatocellular Lipid Levels in Overweight Adults: A Randomized Clinical Trial. JAMA Netw Open 2020; 3:e2025454. [PMID: 33252690 PMCID: PMC7705596 DOI: 10.1001/jamanetworkopen.2020.25454] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPORTANCE Excess body weight and insulin resistance lead to type 2 diabetes and other major health problems. There is an urgent need for dietary interventions to address these conditions. OBJECTIVE To measure the effects of a low-fat vegan diet on body weight, insulin resistance, postprandial metabolism, and intramyocellular and hepatocellular lipid levels in overweight adults. DESIGN, SETTING, AND PARTICIPANTS This 16-week randomized clinical trial was conducted between January 2017 and February 2019 in Washington, DC. Of 3115 people who responded to flyers in medical offices and newspaper and radio advertisements, 244 met the participation criteria (age 25 to 75 years; body mass index of 28 to 40) after having been screened by telephone. INTERVENTIONS Participants were randomized in a 1:1 ratio. The intervention group (n = 122) was asked to follow a low-fat vegan diet and the control group (n = 122) to make no diet changes for 16 weeks. MAIN OUTCOMES AND MEASURES At weeks 0 and 16, body weight was assessed using a calibrated scale. Body composition and visceral fat were measured by dual x-ray absorptiometry. Insulin resistance was assessed with the homeostasis model assessment index and the predicted insulin sensitivity index (PREDIM). Thermic effect of food was measured by indirect calorimetry over 3 hours after a standard liquid breakfast (720 kcal). In a subset of participants (n = 44), hepatocellular and intramyocellular lipids were quantified by proton magnetic resonance spectroscopy. Repeated measure analysis of variance was used for statistical analysis. RESULTS Among the 244 participants in the study, 211 (87%) were female, 117 (48%) were White, and the mean (SD) age was 54.4 (11.6) years. Over the 16 weeks, body weight decreased in the intervention group by 5.9 kg (95% CI, 5.0-6.7 kg; P < .001). Thermic effect of food increased in the intervention group by 14.1% (95% CI, 6.5-20.4; P < .001). The homeostasis model assessment index decreased (-1.3; 95% CI, -2.2 to -0.3; P < .001) and PREDIM increased (0.9; 95% CI, 0.5-1.2; P < .001) in the intervention group. Hepatocellular lipid levels decreased in the intervention group by 34.4%, from a mean (SD) of 3.2% (2.9%) to 2.4% (2.2%) (P = .002), and intramyocellular lipid levels decreased by 10.4%, from a mean (SD) of 1.6 (1.1) to 1.5 (1.0) (P = .03). None of these variables changed significantly in the control group over the 16 weeks. The change in PREDIM correlated negatively with the change in body weight (r = -0.43; P < .001). Changes in hepatocellular and intramyocellular lipid levels correlated with changes in insulin resistance (both r = 0.51; P = .01). CONCLUSIONS AND RELEVANCE A low-fat plant-based dietary intervention reduces body weight by reducing energy intake and increasing postprandial metabolism. The changes are associated with reductions in hepatocellular and intramyocellular fat and increased insulin sensitivity. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02939638.
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Affiliation(s)
- Hana Kahleova
- Physicians Committee for Responsible Medicine, Washington, DC
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Gerald I. Shulman
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
- Department of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
| | - Jihad Alwarith
- Physicians Committee for Responsible Medicine, Washington, DC
| | - Emilie Rembert
- Physicians Committee for Responsible Medicine, Washington, DC
| | - Andrea Tura
- Metabolic Unit, CNR Institute of Neuroscience, Padua, Italy
| | - Martin Hill
- Institute of Endocrinology, Prague, Czech Republic
| | | | - Neal D. Barnard
- Physicians Committee for Responsible Medicine, Washington, DC
- George Washington University School of Medicine and Health Sciences, Washington, DC
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15
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Poggiogalle E, Mendes I, Ong B, Prado CM, Mocciaro G, Mazidi M, Lubrano C, Lenzi A, Donini LM, Siervo M. Sarcopenic obesity and insulin resistance: Application of novel body composition models. Nutrition 2020; 75-76:110765. [DOI: 10.1016/j.nut.2020.110765] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 11/08/2019] [Accepted: 01/28/2020] [Indexed: 01/06/2023]
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16
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Ren G, Bowers RL, Kim T, Araya-Ramirez F, Mahurin AJ, Dean DM, Grandjean PW, Mathews ST. Alterations of Serum Ser312-Phosphorylated Fetuin-A from Exercise-Induced Moderate Body Weight Loss in Individuals with Obesity. Obesity (Silver Spring) 2020; 28:544-551. [PMID: 32012464 DOI: 10.1002/oby.22730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/14/2019] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Phosphorylated fetuin-A (pFet-A) inhibits insulin action and has been shown to be associated with obesity and insulin resistance. The objective of this cohort study was to assess the effect of incremental body weight loss on alterations in serum pFet-A and indexes of insulin sensitivity. METHODS A total of 16 men with obesity attained a targeted weight loss of 8% to 10% of their initial body weight by achieving an energy expenditure/deficit of 2,000 to 2,500 kcal/wk. Anthropometric assessments and blood samples were obtained every 4 weeks. Weight loss was calculated and partitioned as 2% to 4%, 4% to 6%, 6% to 8%, and 8% to 10% compared with initial body weight. RESULTS Targeted body weight loss of 8% to 10% decreased serum pFet-A, pFet-A:Fet-A ratio, fasting insulin, log(homeostasis model assessment of insulin resistance), quantitative insulin sensitivity check index, adipose insulin resistance, and insulin resistance index significantly. Percent changes in serum pFet-A were associated with percent changes in indexes of insulin sensitivity. Unlike insulin sensitivity indexes, which were altered starting with 6% to 8% weight loss, serum pFet-A levels were significantly decreased by 19.6% starting with 2% to 4% weight loss and decreased by 25.6%, 36.8%, and 42.3% with 4% to 6%, 6% to 8%, and 8% to 10% weight loss, respectively. CONCLUSIONS This study reports for the first time that the insulin-sensitizing effects of moderate weight loss are associated with a reduction in serum pFet-A levels.
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Affiliation(s)
- Guang Ren
- Department of Nutrition and Dietetics, Auburn University, Auburn, Alabama, USA
| | - Robert L Bowers
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | - Teayoun Kim
- Department of Nutrition and Dietetics, Auburn University, Auburn, Alabama, USA
| | | | - A Jack Mahurin
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | - David M Dean
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
| | | | - Suresh T Mathews
- Department of Nutrition and Dietetics, Auburn University, Auburn, Alabama, USA
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17
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18
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Halpern B, Mancini MC. Metabolic surgery for the treatment of type 2 diabetes in patients with BMI lower than 35 kg/m 2 : Why caution is still needed. Obes Rev 2019; 20:633-647. [PMID: 30821085 DOI: 10.1111/obr.12837] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/17/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022]
Abstract
Bariatric surgery has shifted from being a risky procedure to an evidence-based one, with proven benefits on all-cause mortality, cardiovascular disease, cancer, and diabetes control. The procedure has an overall positive result on type 2 diabetes mellitus (T2DM), with a substantial number of patients achieving disease remission. This has resulted in several studies assessing possible weight-independent effects of bariatric surgery on glycemic improvement, in addition to recommendation of the procedure to patients with class 1 obesity and T2DM, for whom the procedure was classically not indicated, and adoption of a new term, "metabolic surgery," to highlight the overall metabolic benefit of the procedure beyond weight loss. Recently, the Diabetes Surgery Summit (DSS) has included metabolic surgery in its T2DM treatment algorithm. Although the discussion brought by this consensus is highly relevant, the recommendation of metabolic surgery for patients with uncontrolled T2DM and a body mass index of 30 to 35 kg/m2 still lacks enough evidence. This article provides an overall view of the metabolic benefits of bariatric/metabolic surgery in patients with class 1 obesity, compares the procedure against clinical treatment, and presents our rationale for defending caution on recommending the procedure to less obese individuals.
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Affiliation(s)
- Bruno Halpern
- Obesity Group, Department of Endocrinology and Metabolism, Clinics Hospital, University of São Paulo Medical School, São Paulo, Brazil
| | - Marcio Correa Mancini
- Obesity Group, Department of Endocrinology and Metabolism, Clinics Hospital, University of São Paulo Medical School, São Paulo, Brazil
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19
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Sun S, Sun F, Wang Y. Multi-Level Comparative Framework Based on Gene Pair-Wise Expression Across Three Insulin Target Tissues for Type 2 Diabetes. Front Genet 2019; 10:252. [PMID: 30972105 PMCID: PMC6443994 DOI: 10.3389/fgene.2019.00252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/06/2019] [Indexed: 11/30/2022] Open
Abstract
Type 2 diabetes (T2D) is known as a disease caused by gene alterations characterized by insulin resistance, thus the insulin-responsive tissues are of great interest for T2D study. It’s of great relevance to systematically investigate commonalities and specificities of T2D among those tissues. Here we establish a multi-level comparative framework across three insulin target tissues (white adipose, skeletal muscle, and liver) to provide a better understanding of T2D. Starting from the ranks of gene expression, we constructed the ‘disease network’ through detecting diverse interactions to provide a well-characterization for disease affected tissues. Then, we applied random walk with restart algorithm to the disease network to prioritize its nodes and edges according to their association with T2D. Finally, we identified a merged core module by combining the clustering coefficient and Jaccard index, which can provide elaborate and visible illumination of the common and specific features for different tissues at network level. Taken together, our network-, gene-, and module-level characterization across different tissues of T2D hold the promise to provide a broader and deeper understanding for T2D mechanism.
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Affiliation(s)
- Shaoyan Sun
- School of Mathematics and Statistics, Ludong University, Yantai, China
| | - Fengnan Sun
- Clinical Laboratory, Yantaishan Hospital, Yantai, China
| | - Yong Wang
- CEMS, NCMIS, MDIS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
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20
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Fischer M, Oberänder N, Kaufmann J, Kirsche V, Prodehl G, Schäfer AO, Weimann A. Changes in intra- and extramyocellular lipids in morbidly obese patients after non-surgical weight loss-a pilot study using magnetic resonance spectroscopy. Clin Nutr ESPEN 2018; 28:121-126. [PMID: 30390868 DOI: 10.1016/j.clnesp.2018.08.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 08/25/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Lipid accumulation in muscles is common in obesity and associated with increased risks for insulin resistance. However, the impact of weight loss and exercise on muscle fat content is not clear due to inconsistent data. We used magnetic resonance spectroscopy (MRS) to compare the intra- (IMCL) and extramyocellular lipid (EMCL) proportions in the musculus tibialis anterior of extremely obese patients before and after weight loss. METHODS Nineteen non-diabetic patients with a Body Mass Index (BMI) ≥ 40 kg/m2 who participated in a non-surgical multimodal weight loss program were recruited. Metabolite ratios of IMCL and EMCL (metabolite/creatine) were assessed using 3 T 1H-MRS before therapy and after 6 months. The primary outcome comprised changes in IMCL and body cell mass. Additionally, changes of IMCL and EMCL were compared with changes in standard clinical measures, i.e., BMI, body composition, blood pressure and functional exercise capacity. RESULTS After 6 months the relative weight loss was 24.8% (127.6 kg, 48.5 kg/m2 vs. 96 kg, 36.5 kg/m2). All standard clinical measures were significantly improved. MRS data from 10 patients provided complete and evaluable data sets. IMCL was reduced by nearly 50% (p < .05). The reduction of EMCL was not significant (p = .106). An explorative correlation analysis between changes of IMCL and changes of the standard measures did not reveal any significance. CONCLUSIONS Significant reductions of IMCL following a successful conservative weight loss intervention are detectable by using MRS. These changes may have the potential to serve as an additional marker of clinically meaningful obesity treatment.
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Affiliation(s)
- Martin Fischer
- St. George Obesity Treatment Study Group, Klinikum St. Georg, 04129 Leipzig, Germany
| | - Nadine Oberänder
- St. George Obesity Treatment Study Group, Klinikum St. Georg, 04129 Leipzig, Germany
| | - Jörn Kaufmann
- Neurologische Universitätsklinik, Otto-von-Guericke Universität Magdeburg, Germany
| | - Viktor Kirsche
- St. George Obesity Treatment Study Group, Klinikum St. Georg, 04129 Leipzig, Germany
| | - Guido Prodehl
- St. George Obesity Treatment Study Group, Klinikum St. Georg, 04129 Leipzig, Germany
| | | | - Arved Weimann
- St. George Obesity Treatment Study Group, Klinikum St. Georg, 04129 Leipzig, Germany.
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21
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Chooi YC, Ding C, Chan Z, Choo J, Sadananthan SA, Michael N, Lee Y, Velan SS, Magkos F. Moderate Weight Loss Improves Body Composition and Metabolic Function in Metabolically Unhealthy Lean Subjects. Obesity (Silver Spring) 2018; 26:1000-1007. [PMID: 29676049 DOI: 10.1002/oby.22185] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/26/2018] [Accepted: 03/12/2018] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Individuals who have "metabolically obese normal weight" (MONW) have an increased risk for cardiometabolic disease. Moderate weight loss has multiple benefits in people with obesity, but its effects in lean people are unknown. Thus, the effects of diet-induced 5% weight loss on body composition and metabolic function in MONW subjects were evaluated. METHODS Total body fat, visceral adipose tissue (VAT) and subcutaneous abdominal adipose tissue (SAT) volumes, intrahepatic and intramyocellular lipid contents, insulin sensitivity (hyperinsulinemic-euglycemic clamp), glucose tolerance, and postprandial insulin secretion and clearance rates (mixed meal with minimal modeling) were measured before and after 4.8% ± 0.5% weight loss in 11 MONW Asians (48 ± 3 years old, six men and five women, BMI 22.7 ± 0.4 kg/m2 ). RESULTS Weight loss decreased total fat mass by ∼9%, VAT and SAT volumes by ∼11% and ∼17%, respectively, and intrahepatic fat by ∼50% (all P < 0.05). Fasting plasma insulin, triglyceride, and total low- and high-density lipoprotein cholesterol concentrations were also reduced (P < 0.05). Insulin sensitivity indexes (M-value and M/I ratio) increased by 21% to 26% (both P < 0.05); β-cell responsivity and postprandial insulin secretion rate did not change, but insulin clearance rate increased by 16% (P < 0.05). CONCLUSIONS Diet-induced moderate weight loss improves body composition, lipid profile, and insulin sensitivity and thereby reduces cardiometabolic risk in MONW Asians.
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Affiliation(s)
- Yu Chung Chooi
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
| | - Cherlyn Ding
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
| | - Zhiling Chan
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
| | - John Choo
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
| | - Suresh Anand Sadananthan
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore
| | - Navin Michael
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore
| | - Yijun Lee
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
| | - S Sendhil Velan
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore
- Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore
| | - Faidon Magkos
- Clinical Nutrition Research Centre, Agency for Science, Technology and Research, National University Health System, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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22
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Daemen S, van Polanen N, Hesselink MKC. The effect of diet and exercise on lipid droplet dynamics in human muscle tissue. ACTA ACUST UNITED AC 2018. [PMID: 29514886 DOI: 10.1242/jeb.167015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The majority of fat in the human body is stored as triacylglycerols in white adipose tissue. In the obese state, adipose tissue mass expands and excess lipids are stored in non-adipose tissues, such as skeletal muscle. Lipids are stored in skeletal muscle in the form of small lipid droplets. Although originally viewed as dull organelles that simply store lipids as a consequence of lipid overflow from adipose tissue, lipid droplets are now recognized as key components in the cell that exert a variety of relevant functions in multiple tissues (including muscle). Here, we review the effect of diet and exercise interventions on myocellular lipid droplets and their putative role in insulin sensitivity from a human perspective. We also provide an overview of lipid droplet biology and identify gaps for future research.
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Affiliation(s)
- Sabine Daemen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Nynke van Polanen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
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23
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24
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Wang H, Arias EB, Yu CS, Verkerke ARP, Cartee GD. Effects of Calorie Restriction and Fiber Type on Glucose Uptake and Abundance of Electron Transport Chain and Oxidative Phosphorylation Proteins in Single Fibers from Old Rats. J Gerontol A Biol Sci Med Sci 2017; 72:1638-1646. [PMID: 28531280 DOI: 10.1093/gerona/glx099] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Indexed: 11/13/2022] Open
Abstract
Calorie restriction (CR; reducing calorie intake by ~40% below ad libitum) can increase glucose uptake by insulin-stimulated muscle. Because skeletal muscle is comprised of multiple, heterogeneous fiber types, our primary aim was to determine the effects of CR (initiated at 14 weeks old) and fiber type on insulin-stimulated glucose uptake by single fibers of diverse fiber types in 23-26-month-old rats. Isolated epitrochlearis muscles from AL and CR rats were incubated with [3H]-2-deoxyglucose ± insulin. Glucose uptake and fiber type were determined for single fibers dissected from the muscles. We also determined CR-effects on abundance of several key metabolic proteins in single fibers. CR resulted in: (a) significantly (p < .05 to .001) greater glucose uptake by insulin-stimulated type I, IIA, IIB, IIBX, and IIX fibers; (b) significantly (p < .05 to .001) reduced abundance of several mitochondrial electron transport chain (ETC) and oxidative phosphorylation (OxPhos) proteins in type I, IIA, and IIBX but not IIB and IIX fibers; and (c) unaltered hexokinase II abundance in each fiber type. These results demonstrate that CR can enhance glucose uptake in each fiber type of rat skeletal muscle in the absence of upregulation of the abundance of hexokinase II or key mitochondrial ETC and OxPhos proteins.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor
| | - Carmen S Yu
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor
| | - Anthony R P Verkerke
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor.,Institute of Gerontology, University of Michigan, Ann Arbor
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25
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Haddow JE, Lambert-Messerlian G, Eklund E, Neveux LM, Palomaki GE. Peripheral deiodinase activity: A potential explanation for the association between maternal weight and gestational hyperglycemia. Obstet Med 2017; 11:73-78. [PMID: 29997689 DOI: 10.1177/1753495x17733223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 08/23/2017] [Indexed: 12/20/2022] Open
Abstract
Background High maternal weight is known to associate with both low free thyroxine and gestational diabetes mellitus. We explore a deiodinase-related mechanism that may help explain these associations. Methods Among 108 women receiving routine oral glucose tolerance testing for gestational diabetes mellitus, we collected biophysical data and measured free thyroxine and total triiodothyronine, using residual plasma samples. Results Fasting triiodothyronine/free thyroxine ratio and triiodothyronine were higher among women with gestational diabetes mellitus (p = 0.02; p = 0.04). The triiodothyronine/free thyroxine ratio and triiodothyronine measurements at 2 h were associated with weight (r = 0.20, p = 0.04; r = 0.22, p = 0.02); free thyroxine showed a non-significant inverse weight relationship (r = -0.06, p = 0.55). Glucose at all four intervals was associated with triiodothyronine/free thyroxine ratios, and triiodothyronine at 2 h. In stepwise regression, triiodothyronine/free thyroxine ratio predicted glucose more strongly than did weight. Conclusion These relationships may be explained by higher maternal weight inducing peripheral deiodinase activity, resulting in higher plasma glucose (via triiodothyronine stimulation) and thereby increasing gestational diabetes mellitus risk.
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Affiliation(s)
- James E Haddow
- Department of Pathology and Laboratory Medicine, Division of Medical Screening and Special Testing, Women and Infants Hospital/Alpert Medical School of Brown University, Providence, RI, USA.,Savjani Institute for Health Research, Windham, ME, USA
| | - Geralyn Lambert-Messerlian
- Department of Pathology and Laboratory Medicine, Division of Medical Screening and Special Testing, Women and Infants Hospital/Alpert Medical School of Brown University, Providence, RI, USA
| | - Elizabeth Eklund
- Department of Pathology and Laboratory Medicine, Division of Medical Screening and Special Testing, Women and Infants Hospital/Alpert Medical School of Brown University, Providence, RI, USA
| | - Louis M Neveux
- Department of Pathology and Laboratory Medicine, Division of Medical Screening and Special Testing, Women and Infants Hospital/Alpert Medical School of Brown University, Providence, RI, USA.,Savjani Institute for Health Research, Windham, ME, USA
| | - Glenn E Palomaki
- Department of Pathology and Laboratory Medicine, Division of Medical Screening and Special Testing, Women and Infants Hospital/Alpert Medical School of Brown University, Providence, RI, USA.,Savjani Institute for Health Research, Windham, ME, USA
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26
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Frechette DM, Krishnamoorthy D, Pamon T, Chan ME, Patel V, Rubin CT. Mechanical signals protect stem cell lineage selection, preserving the bone and muscle phenotypes in obesity. Ann N Y Acad Sci 2017; 1409:33-50. [PMID: 28891202 DOI: 10.1111/nyas.13442] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/19/2017] [Accepted: 06/28/2017] [Indexed: 12/18/2022]
Abstract
The incidence of obesity is rapidly rising, increasing morbidity and mortality rates worldwide. Associated comorbidities include type 2 diabetes, heart disease, fatty liver disease, and cancer. The impact of excess fat on musculoskeletal health is still unclear, although it is associated with increased fracture risk and a decline in muscular function. The complexity of obesity makes understanding the etiology of bone and muscle abnormalities difficult. Exercise is an effective and commonly prescribed nonpharmacological treatment option, but it can be difficult or unsafe for the frail, elderly, and morbidly obese. Exercise alternatives, such as low-intensity vibration (LIV), have potential for improving musculoskeletal health, particularly in conditions with excess fat. LIV has been shown to influence bone marrow mesenchymal stem cell differentiation toward higher-order tissues (i.e., bone) and away from fat. While the exact mechanisms are not fully understood, recent studies utilizing LIV both at the bench and in the clinic have demonstrated some efficacy. Here, we discuss the current literature investigating the effects of obesity on bone, muscle, and bone marrow and how exercise and LIV can be used as effective treatments for combating the negative effects in the presence of excess fat.
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Affiliation(s)
- Danielle M Frechette
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Divya Krishnamoorthy
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Tee Pamon
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - M Ete Chan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Vihitaben Patel
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
| | - Clinton T Rubin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York
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27
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Evans RA, Frese M, Romero J, Cunningham JH, Mills KE. Fructose replacement of glucose or sucrose in food or beverages lowers postprandial glucose and insulin without raising triglycerides: a systematic review and meta-analysis. Am J Clin Nutr 2017; 106:506-518. [PMID: 28592611 DOI: 10.3945/ajcn.116.145151] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 05/01/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Conflicting evidence exists on the effects of fructose consumption in people with type 1 and type 2 diabetes mellitus. No systematic review has addressed the effect of isoenergetic fructose replacement of glucose or sucrose on peak postprandial glucose, insulin, and triglyceride concentrations.Objective: The objective of this study was to review the evidence for postprandial glycemic and insulinemic responses after isoenergetic replacement of either glucose or sucrose in foods or beverages with fructose.Design: We searched the Cochrane Library, MEDLINE, EMBASE, the WHO International Clinical Trials Registry Platform Search Portal, and clinicaltrials.gov The date of the last search was 26 April 2016. We included randomized controlled trials measuring peak postprandial glycemia after isoenergetic replacement of glucose, sucrose, or both with fructose in healthy adults or children with or without diabetes. The main outcomes analyzed were peak postprandial blood glucose, insulin, and triglyceride concentrations.Results: Replacement of either glucose or sucrose by fructose resulted in significantly lowered peak postprandial blood glucose, particularly in people with prediabetes and type 1 and type 2 diabetes. Similar results were obtained for insulin. Peak postprandial blood triglyceride concentrations did not significantly increase.Conclusions: Strong evidence exists that substituting fructose for glucose or sucrose in food or beverages lowers peak postprandial blood glucose and insulin concentrations. Isoenergetic replacement does not result in a substantial increase in blood triglyceride concentrations.
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Affiliation(s)
| | - Michael Frese
- Health Research Institute.,Faculty of Education, Science, Technology and Mathematics, and
| | - Julio Romero
- Department of Software Engineering and Artificial Intelligence, University of Canberra, Canberra, Australia; and
| | - Judy H Cunningham
- Formerly of Risk Assessment Chemical Safety and Nutrition, Food Standards Australia New Zealand, Canberra, Australia
| | - Kerry E Mills
- Health Research Institute, .,Faculty of Education, Science, Technology and Mathematics, and
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Clamp LD, Hume DJ, Lambert EV, Kroff J. Enhanced insulin sensitivity in successful, long-term weight loss maintainers compared with matched controls with no weight loss history. Nutr Diabetes 2017. [PMID: 28628125 PMCID: PMC5519190 DOI: 10.1038/nutd.2017.31] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Background: Weight gain is associated with deterioration in metabolic health, whereas weight loss improves insulin sensitivity. This study assesses the impact of long-term, successfully maintained weight loss and weight-loss relapse on measures of insulin sensitivity and identifies factors that explain variability in insulin sensitivity. Methods: Women (20–45 years) were recruited into four groups: reduced-overweight/obese (RED, n=15); body mass index (BMI)-matched controls (stable low-weight, n=19), BMI⩽27 kg m−2; relapsed-overweight/obese subjects (REL, n=11); and BMI-matched controls (obese stable weight, n=11), BMI⩾27 kg m−2. A 75 g oral glucose tolerance test determined fasting and 2 h plasma glucose and insulin. Homeostatic Model Assessment (HOMA-IR) and insulin sensitivity index (ISI(0,120)) assessed insulin sensitivity. Anthropometric measurements, fasting resting metabolic rate (RMR) and respiratory quotient (RQ) were measured. Questionnaires and dietary intake were recorded, and physical activity was measured using accelerometers. Results: RED were more insulin sensitive, characterised by lower fasting (P=0.001) and 2 h insulin (P=0.003) levels compared with all other groups. There were no significant differences in dietary intake, sedentary, light and moderate activity, RMR or RQ in the RED compared with the other three groups. % Body weight (BW) lost (P<0.001), % BW regained (P<0.05), body fat %, light activity (P<0.05, only log HOMA), vigorous activity (P<0.05) and RQ (P<0.01) predicted 61.4% and 59.7% of variability in log HOMA and log ISI(0,120), respectively, in multiple linear regression models. Conclusion: This study showed sustained enhanced insulin sensitivity in successful weight loss maintainers compared with BMI-matched controls with no weight loss history. Weight-loss-relapsed individuals were indistinguishable from controls. Weight loss itself was the strongest predictor of improved insulin sensitivity, whereas weight regain significantly predicted reduced insulin sensitivity. Weight-loss maintenance programs are essential to retaining metabolic benefits acquired through weight loss. Being physically active, reducing sedentary behaviour and, in particular, including small amounts of vigorous physical activity significantly predicted improved insulin sensitivity.
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Affiliation(s)
- L D Clamp
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - D J Hume
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - E V Lambert
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - J Kroff
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Zhang J, Light AR, Hoppel CL, Campbell C, Chandler CJ, Burnett DJ, Souza EC, Casazza GA, Hughen RW, Keim NL, Newman JW, Hunter GR, Fernandez JR, Garvey WT, Harper ME, Fiehn O, Adams SH. Acylcarnitines as markers of exercise-associated fuel partitioning, xenometabolism, and potential signals to muscle afferent neurons. Exp Physiol 2016; 102:48-69. [PMID: 27730694 DOI: 10.1113/ep086019] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 10/07/2016] [Indexed: 01/18/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does improved metabolic health and insulin sensitivity following a weight-loss and fitness intervention in sedentary, obese women alter exercise-associated fuel metabolism and incomplete mitochondrial fatty acid oxidation (FAO), as tracked by blood acylcarnitine patterns? What is the main finding and its importance? Despite improved fitness and blood sugar control, indices of incomplete mitochondrial FAO increased in a similar manner in response to a fixed load acute exercise bout; this indicates that intramitochondrial muscle FAO is inherently inefficient and is tethered directly to ATP turnover. With insulin resistance or type 2 diabetes mellitus, mismatches between mitochondrial fatty acid fuel delivery and oxidative phosphorylation/tricarboxylic acid cycle activity may contribute to inordinate accumulation of short- or medium-chain acylcarnitine fatty acid derivatives [markers of incomplete long-chain fatty acid oxidation (FAO)]. We reasoned that incomplete FAO in muscle would be ameliorated concurrent with improved insulin sensitivity and fitness following a ∼14 week training and weight-loss intervention in obese, sedentary, insulin-resistant women. Contrary to this hypothesis, overnight-fasted and exercise-induced plasma C4-C14 acylcarnitines did not differ between pre- and postintervention phases. These metabolites all increased robustly with exercise (∼45% of pre-intervention peak oxygen consumption) and decreased during a 20 min cool-down. This supports the idea that, regardless of insulin sensitivity and fitness, intramitochondrial muscle β-oxidation and attendant incomplete FAO are closely tethered to absolute ATP turnover rate. Acute exercise also led to branched-chain amino acid acylcarnitine derivative patterns suggestive of rapid and transient diminution of branched-chain amino acid flux through the mitochondrial branched-chain ketoacid dehydrogenase complex. We confirmed our prior novel observation that a weight-loss/fitness intervention alters plasma xenometabolites [i.e. cis-3,4-methylene-heptanoylcarnitine and γ-butyrobetaine (a co-metabolite possibly derived in part from gut bacteria)], suggesting that host metabolic health regulated gut microbe metabolism. Finally, we considered whether acylcarnitine metabolites signal to muscle-innervating afferents; palmitoylcarnitine at concentrations as low as 1-10 μm activated a subset (∼2.5-5%) of these neurons ex vivo. This supports the hypothesis that in addition to tracking exercise-associated shifts in fuel metabolism, muscle acylcarnitines act as signals of exertion to short-loop somatosensory-motor circuits or to the brain.
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Affiliation(s)
- Jie Zhang
- Anesthesiology Department, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Alan R Light
- Anesthesiology Department, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Charles L Hoppel
- Pharmacology Department, Case Western Reserve University, Cleveland, OH, USA
| | - Caitlin Campbell
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA
| | - Carol J Chandler
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA
| | - Dustin J Burnett
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA
| | - Elaine C Souza
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA
| | - Gretchen A Casazza
- Sports Medicine Program, School of Medicine, University of California, Davis, CA, USA
| | - Ronald W Hughen
- Anesthesiology Department, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nancy L Keim
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA.,Department of Nutrition, University of California, Davis, CA, USA
| | - John W Newman
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA.,Department of Nutrition, University of California, Davis, CA, USA
| | - Gary R Hunter
- Department of Nutrition Sciences, University of Alabama, Birmingham, AL, USA.,Human Studies Department, University of Alabama, Birmingham, AL, USA
| | - Jose R Fernandez
- Department of Nutrition Sciences, University of Alabama, Birmingham, AL, USA
| | - W Timothy Garvey
- Department of Nutrition Sciences, University of Alabama, Birmingham, AL, USA
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Oliver Fiehn
- Genome Center and West Coast Metabolomics Center, University of California, Davis, CA, USA.,Biochemistry Department, King Abdulaziz University, Jeddah, Saudi-Arabia
| | - Sean H Adams
- Arkansas Children's Nutrition Center, Little Rock, AR, USA.,Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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30
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Gilliland T, Dufour S, Shulman GI, Petersen KF, Emre SH. Resolution of non-alcoholic steatohepatitis after growth hormone replacement in a pediatric liver transplant patient with panhypopituitarism. Pediatr Transplant 2016; 20:1157-1163. [PMID: 27762491 DOI: 10.1111/petr.12819] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/06/2016] [Indexed: 12/14/2022]
Abstract
NAFLD is a common condition linked to obesity, type 2 diabetes, and metabolic syndrome. Simple hepatic steatosis is a risk factor for inflammatory reactions in the liver (NASH), which may lead to cirrhosis. While the mechanism is unclear, NAFLD and NASH are associated with panhypopituitarism, which in the pediatric population often results from craniopharyngioma or pituitary adenoma and the sequelae of treatment, causing hypothyroidism, adrenal insufficiency, hypogonadotropic hypogonadism, and GH deficiency. Refractory NAFLD in panhypopituitarism may be amenable to GH replacement. Here, we report a pediatric case of NASH secondary to panhypopituitarism from craniopharyngioma, which recurred by 11 months after LDLT. Despite low-dose GH replacement, the patient remained GH deficient. Pubertal dosed GH therapy led to rapid and complete resolution of hepatic steatosis, which we tracked using serial 1 H MRS. Pediatric patients with NASH cirrhosis secondary to panhypopituitarism can be good candidates for liver transplantation, but hormone deficiencies predispose to recurrence after transplant. High-dose GH replacement should be considered in pediatric patients with GH deficiency and recurrent disease. A multidisciplinary team approach is essential for successful outcomes.
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Affiliation(s)
- Thomas Gilliland
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Department of Surgery, Yale University School of Medicine, New Haven, CT, USA
| | - Sylvie Dufour
- Howard Hughes Medical Institutes, Yale University School of Medicine, New Haven, CT, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institutes, Yale University School of Medicine, New Haven, CT, USA.,Novo-Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.,Novo-Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Sukru H Emre
- Department of Surgery, Yale University School of Medicine, New Haven, CT, USA
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31
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McCurdy CE, Schenk S, Hetrick B, Houck J, Drew BG, Kaye S, Lashbrook M, Bergman BC, Takahashi DL, Dean TA, Nemkov T, Gertsman I, Hansen KC, Philp A, Hevener AL, Chicco AJ, Aagaard KM, Grove KL, Friedman JE. Maternal obesity reduces oxidative capacity in fetal skeletal muscle of Japanese macaques. JCI Insight 2016; 1:e86612. [PMID: 27734025 DOI: 10.1172/jci.insight.86612] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Maternal obesity is proposed to alter the programming of metabolic systems in the offspring, increasing the risk for developing metabolic diseases; however, the cellular mechanisms remain poorly understood. Here, we used a nonhuman primate model to examine the impact of a maternal Western-style diet (WSD) alone, or in combination with obesity (Ob/WSD), on fetal skeletal muscle metabolism studied in the early third trimester. We find that fetal muscle responds to Ob/WSD by upregulating fatty acid metabolism, mitochondrial complex activity, and metabolic switches (CPT-1, PDK4) that promote lipid utilization over glucose oxidation. Ob/WSD fetuses also had reduced mitochondrial content, diminished oxidative capacity, and lower mitochondrial efficiency in muscle. The decrease in oxidative capacity and glucose metabolism was persistent in primary myotubes from Ob/WSD fetuses despite no additional lipid-induced stress. Switching obese mothers to a healthy diet prior to pregnancy did not improve fetal muscle mitochondrial function. Lastly, while maternal WSD alone led only to intermediary changes in fetal muscle metabolism, it was sufficient to increase oxidative damage and cellular stress. Our findings suggest that maternal obesity or WSD, alone or in combination, leads to programmed decreases in oxidative metabolism in offspring muscle. These alterations may have important implications for future health.
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Affiliation(s)
- Carrie E McCurdy
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA.,Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California, USA
| | - Byron Hetrick
- Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Julie Houck
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Brian G Drew
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, University of California, Los Angeles, Los Angeles, California, USA.,Diabetes and Dyslipidaemia Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, Victoria, Australia
| | - Spencer Kaye
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Melanie Lashbrook
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Bryan C Bergman
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Diana L Takahashi
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Tyler A Dean
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ilya Gertsman
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Andrew Philp
- School of Sport Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Andrea L Hevener
- David Geffen School of Medicine, Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, University of California, Los Angeles, Los Angeles, California, USA
| | - Adam J Chicco
- Departments of Health and Exercise Science and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Kjersti M Aagaard
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Kevin L Grove
- Division of Diabetes, Obesity and Metabolism, Oregon National Primate Research Center, Beaverton, Oregon, USA.,Novo Nordisk Research Center, Seattle, Washington, USA
| | - Jacob E Friedman
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Schooneman MG, Napolitano A, Houten SM, Ambler GK, Murgatroyd PR, Miller SR, Hollak CEM, Tan CY, Virtue S, Vidal-Puig A, Nunez DJ, Soeters MR. Assessment of plasma acylcarnitines before and after weight loss in obese subjects. Arch Biochem Biophys 2016; 606:73-80. [PMID: 27444119 DOI: 10.1016/j.abb.2016.07.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 07/14/2016] [Accepted: 07/17/2016] [Indexed: 12/22/2022]
Abstract
Acylcarnitines, fatty acid oxidation (FAO) intermediates, have been implicated in diet-induced insulin resistance and type 2 diabetes mellitus, as increased levels are found in obese insulin resistant humans. Moreover plasma acylcarnitines have been associated with clinical parameters related to glucose metabolism, such as fasting glucose levels and HbA1c. We hypothesized that plasma acylcarnitines would correlate with energy expenditure, insulin sensitivity and other clinical parameters before and during a weight loss intervention. We measured plasma acylcarnitines in 60 obese subjects before and after a 12 week weight loss intervention. These samples originated from three different interventions (diet alone (n = 20); diet and exercise (n = 21); diet and drug treatment (n = 19)). Acylcarnitine profiles were analysed in relation to clinical parameters of glucose metabolism, insulin sensitivity and energy expenditure. Conclusions were drawn from all 60 subjects together. Despite amelioration of HOMA-IR, plasma acylcarnitines levels increased during weight loss. HOMA-IR, energy expenditure and respiratory exchange ratio were not related to plasma acylcarnitines. However non-esterified fatty acids correlated strongly with several acylcarnitines at baseline and during the weight loss intervention (p < 0.001). Acylcarnitines did not correlate with clinical parameters of glucose metabolism during weight loss, questioning their role in insulin resistance and type 2 diabetes mellitus.
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Affiliation(s)
- Marieke G Schooneman
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Clinical Chemistry, Laboratory Genetic Metabolic Diseases, Academic Medical Center, University of Amsterdam, The Netherlands.
| | - Antonella Napolitano
- GlaxoSmithKline Research and Development, Research Triangle Park, NC, 27709, USA
| | - Sander M Houten
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Graeme K Ambler
- Institute of Metabolic Science, Metabolic Research Laboratories, Cambridge University Hospital NHS Trust, Cambridge, UK
| | - Peter R Murgatroyd
- NIHR Wellcome Trust Clinical Research Facility, Cambridge University Hospital NHS Trust, Cambridge, UK
| | - Sam R Miller
- GlaxoSmithKline Research and Development, Research Triangle Park, NC, 27709, USA
| | - Carla E M Hollak
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Chong Y Tan
- Institute of Metabolic Science, Metabolic Research Laboratories, Cambridge University Hospital NHS Trust, Cambridge, UK
| | - Samuel Virtue
- Institute of Metabolic Science, Metabolic Research Laboratories, Cambridge University Hospital NHS Trust, Cambridge, UK
| | - Antonio Vidal-Puig
- Institute of Metabolic Science, Metabolic Research Laboratories, Cambridge University Hospital NHS Trust, Cambridge, UK
| | - Derek J Nunez
- GlaxoSmithKline Research and Development, Research Triangle Park, NC, 27709, USA
| | - Maarten R Soeters
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Institute of Metabolic Science, Metabolic Research Laboratories, Cambridge University Hospital NHS Trust, Cambridge, UK. http://www.metabolism.maartensoeters.nl/
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The Flexibility of Ectopic Lipids. Int J Mol Sci 2016; 17:ijms17091554. [PMID: 27649157 PMCID: PMC5037826 DOI: 10.3390/ijms17091554] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 02/07/2023] Open
Abstract
In addition to the subcutaneous and the visceral fat tissue, lipids can also be stored in non-adipose tissue such as in hepatocytes (intrahepatocellular lipids; IHCL), skeletal (intramyocellular lipids; IMCL) or cardiac muscle cells (intracardiomyocellular lipids; ICCL). Ectopic lipids are flexible fuel stores that can be depleted by physical exercise and repleted by diet. They are related to obesity and insulin resistance. Quantification of IMCL was initially performed invasively, using muscle biopsies with biochemical and/or histological analysis. 1H-magnetic resonance spectroscopy (1H-MRS) is now a validated method that allows for not only quantifying IMCL non-invasively and repeatedly, but also assessing IHCL and ICCL. This review summarizes the current available knowledge on the flexibility of ectopic lipids. The available evidence suggests a complex interplay between quantitative and qualitative diet, fat availability (fat mass), insulin action, and physical exercise, all important factors that influence the flexibility of ectopic lipids. Furthermore, the time frame of the intervention on these parameters (short-term vs. long-term) appears to be critical. Consequently, standardization of physical activity and diet are critical when assessing ectopic lipids in predefined clinical situations.
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Bairy S, Kumar AMV, Raju MSN, Achanta S, Naik B, Tripathy JP, Zachariah R. Is adjunctive naturopathy associated with improved glycaemic control and a reduction in need for medications among type 2 Diabetes patients? A prospective cohort study from India. Altern Ther Health Med 2016; 16:290. [PMID: 27534941 PMCID: PMC4989485 DOI: 10.1186/s12906-016-1264-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 08/05/2016] [Indexed: 01/30/2023]
Abstract
BACKGROUND With an estimated 65 million Diabetes Mellitus (DM) patients, India ranks second in the world in terms of DM burden. The emphasis of current medical practice has been on pharmacotherapy but, despite the best combination therapies, acheiving glycaemic control (reduction of blood sugar to desirable levels) is a challenge. 'Integrated Naturopathy and Yoga'(INY) is an alternative system of medicine that lays emphasis on the role of diet and physical exercise. We assessed the short term effect of INY as an adjunct to pharmacotherapy on glycaemic control among type 2 DM patients. METHODS In this prospective cohort study with a 3 month follow-up, DM patients consecutively admitted to a hospital in India from May-October 2014 for either 15 or 30 days were offered INY - a package of vegetarian diet with no added oil, sugar and salt, yoga-based exercise, patient counselling and rest. A 'favourable outcome' was defined as glycaemic control (glycosylated hemoglobin (HbA1c) < 7 % or absolute reduction by 1 %) along with at least 50 % reduction in antidiabetes medication at 3 months relative to baseline. Compliance to diet was scored by self-report on a scale of 0-10 and categorized into poor (0-5), moderate (6-8) and excellent (9-10). RESULTS Of 101 patients with 3-month follow-up data, 65(65 %) achieved a favourable outcome - with 19(19 %) stopping medication while sustaining glycemic control. Factors associated with favourable outcome were baseline HbA1c and compliance to diet, which showed a significant linear relationship with mean HbA1c reductions of 0.4 %, 1.1 % and 1.7 % in relation to poor, moderate and excellent dietary compliance respectively. CONCLUSION INY, adjunctive to pharmacotherapy, was associated with a significant beneficial effect on glycaemic control and reduced the overall need for antidiabetes medications. These early results are promising. Further studies with long-term follow-up and using more rigorous randomized controlled trial designs are needed.
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Gopalan V, Michael N, Ishino S, Lee SS, Yang AY, Bhanu Prakash KN, Yaligar J, Sadananthan SA, Kaneko M, Zhou Z, Satomi Y, Hirayama M, Kamiguchi H, Zhu B, Horiguchi T, Nishimoto T, Velan SS. Effect of Exercise and Calorie Restriction on Tissue Acylcarnitines, Tissue Desaturase Indices, and Fat Accumulation in Diet-Induced Obese Rats. Sci Rep 2016; 6:26445. [PMID: 27197769 PMCID: PMC4873816 DOI: 10.1038/srep26445] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/29/2016] [Indexed: 11/13/2022] Open
Abstract
Both exercise and calorie restriction interventions have been recommended for inducing weight-loss in obese states. However, there is conflicting evidence on their relative benefits for metabolic health and insulin sensitivity. This study seeks to evaluate the differential effects of the two interventions on fat mobilization, fat metabolism, and insulin sensitivity in diet-induced obese animal models. After 4 months of ad libitum high fat diet feeding, 35 male Fischer F344 rats were grouped (n = 7 per cohort) into sedentary control (CON), exercise once a day (EX1), exercise twice a day (EX2), 15% calorie restriction (CR1) and 30% calorie restriction (CR2) cohorts. Interventions were carried out over a 4-week period. We found elevated hepatic and muscle long chain acylcarnitines with both exercise and calorie restriction, and a positive association between hepatic long chain acylcarnitines and insulin sensitivity in the pooled cohort. Our result suggests that long chain acylcarnitines may not indicate incomplete fat oxidation in weight loss interventions. Calorie restriction was found to be more effective than exercise in reducing body weight. Exercise, on the other hand, was more effective in reducing adipose depots and muscle triglycerides, favorably altering muscle/liver desaturase activity and improving insulin sensitivity.
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Affiliation(s)
- Venkatesh Gopalan
- Laboratory of Molecular Imaging, Singapore Bio Imaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore
| | - Navin Michael
- Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore
| | | | - Swee Shean Lee
- Laboratory of Molecular Imaging, Singapore Bio Imaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore
| | | | - K N Bhanu Prakash
- Laboratory of Molecular Imaging, Singapore Bio Imaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore
| | - Jadegoud Yaligar
- Laboratory of Molecular Imaging, Singapore Bio Imaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore
| | - Suresh Anand Sadananthan
- Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore
| | | | | | | | | | | | - Bin Zhu
- Takeda Singapore Pte Ltd., Singapore
| | - Takashi Horiguchi
- Molecular Imaging Centre, National Institute of Radiological Sciences, Chiba, Japan
| | | | - S Sendhil Velan
- Laboratory of Molecular Imaging, Singapore Bio Imaging Consortium, Agency for Science Technology and Research (A*STAR), Singapore
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36
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Devanathan S, Whitehead TD, Fettig N, Gropler RJ, Nemanich S, Shoghi KI. Sexual dimorphism in myocardial acylcarnitine and triglyceride metabolism. Biol Sex Differ 2016; 7:25. [PMID: 27182432 PMCID: PMC4866274 DOI: 10.1186/s13293-016-0077-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/24/2016] [Indexed: 01/22/2023] Open
Abstract
Background Cardiovascular disease is the leading cause of death among diabetic patients. Importantly, recent data highlight the apparent sexual dimorphism in the pathogenesis of cardiovascular disease in diabetics with respect to both frequency- and age-related risk factors. The disposition to cardiovascular disease among diabetic patients has been attributed, at least in part, to excess lipid supply to the heart culminating in lipotoxicity of the heart and downstream derangements. A confounding factor in obese animal models of diabetes is that increased peripheral lipid availability to the heart can induce cardio-metabolic remodeling independent of the underlying pathophysiology of diabetes, thus masking the diabetic phenotype. To that end, we hypothesized that the use of non-obese diabetic (NOD) animal models will reveal metabolic signatures of diabetes in a sex-specific manner. Methods To test this hypothesis, male and female NOD Goto-Kakizaki (GK) rats were used to assess the expression profile of 84 genes involved in lipid metabolism. In parallel, targeted lipidomics analysis was performed to characterize sex differences in homeostasis of non-esterified fatty acids (NEFA), acylcarnitines (AC), and triglycerides (TG). Results Our analysis revealed significant sex differences in the expression of a broad range of genes involved in transport, activation, and utilization of lipids. Furthermore, NOD male rats exhibited enhanced oxidative metabolism and accumulation of TG, whereas female NOD rats exhibited reduced TG content coupled with accumulation of AC species. Multi-dimensional statistical analysis identified saturated AC16:0, AC18:0, and AC20:0 as dominant metabolites in mediating sex differences in AC metabolism. Confocal microscopy of rat cardiomyocytes exposed to AC14:0, AC16:0, and AC18:0 confirmed induction of ROS with AC18:0 being more potent followed by AC14:0. Conclusion Overall, we demonstrate sex differences in myocardial AC and TG metabolism with implications for therapy and diagnosis of diabetic cardiovascular disease. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0077-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sriram Devanathan
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Timothy D Whitehead
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Nicole Fettig
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Robert J Gropler
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Department of Medicine, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Samuel Nemanich
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Kooresh I Shoghi
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Department of Biomedical Engineering, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Division of Biology and Biomedical Sciences, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
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Effects of Moderate and Subsequent Progressive Weight Loss on Metabolic Function and Adipose Tissue Biology in Humans with Obesity. Cell Metab 2016; 23:591-601. [PMID: 26916363 PMCID: PMC4833627 DOI: 10.1016/j.cmet.2016.02.005] [Citation(s) in RCA: 528] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/04/2016] [Accepted: 02/03/2016] [Indexed: 02/07/2023]
Abstract
Although 5%-10% weight loss is routinely recommended for people with obesity, the precise effects of 5% and further weight loss on metabolic health are unclear. We conducted a randomized controlled trial that evaluated the effects of 5.1% ± 0.9% (n = 19), 10.8% ± 1.3% (n = 9), and 16.4% ± 2.1% (n = 9) weight loss and weight maintenance (n = 14) on metabolic outcomes. 5% weight loss improved adipose tissue, liver and muscle insulin sensitivity, and β cell function, without a concomitant change in systemic or subcutaneous adipose tissue markers of inflammation. Additional weight loss further improved β cell function and insulin sensitivity in muscle and caused stepwise changes in adipose tissue mass, intrahepatic triglyceride content, and adipose tissue expression of genes involved in cholesterol flux, lipid synthesis, extracellular matrix remodeling, and oxidative stress. These results demonstrate that moderate 5% weight loss improves metabolic function in multiple organs simultaneously, and progressive weight loss causes dose-dependent alterations in key adipose tissue biological pathways.
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38
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Ress C, Kaser S. Mechanisms of intrahepatic triglyceride accumulation. World J Gastroenterol 2016; 22:1664-1673. [PMID: 26819531 PMCID: PMC4721997 DOI: 10.3748/wjg.v22.i4.1664] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/20/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
Hepatic steatosis defined as lipid accumulation in hepatocytes is very frequently found in adults and obese adolescents in the Western World. Etiologically, obesity and associated insulin resistance or excess alcohol intake are the most frequent causes of hepatic steatosis. However, steatosis also often occurs with chronic hepatitis C virus (HCV) infection and is also found in rare but potentially life-threatening liver diseases of pregnancy. Clinical significance and outcome of hepatic triglyceride accumulation are highly dependent on etiology and histological pattern of steatosis. This review summarizes current concepts of pathophysiology of common causes of hepatic steatosis, including non-alcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease, chronic HCV infections, drug-induced forms of hepatic steatosis, and acute fatty liver of pregnancy. Regarding the pathophysiology of NAFLD, this work focuses on the close correlation between insulin resistance and hepatic triglyceride accumulation, highlighting the potential harmful effects of systemic insulin resistance on hepatic metabolism of fatty acids on the one side and the role of lipid intermediates on insulin signalling on the other side. Current studies on lipid droplet morphogenesis have identified novel candidate proteins and enzymes in NAFLD.
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39
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Stout MB, Steyn FJ, Jurczak MJ, Camporez JPG, Zhu Y, Hawse JR, Jurk D, Palmer AK, Xu M, Pirtskhalava T, Evans GL, de Souza Santos R, Frank AP, White TA, Monroe DG, Singh RJ, Casaclang-Verzosa G, Miller JD, Clegg DJ, LeBrasseur NK, von Zglinicki T, Shulman GI, Tchkonia T, Kirkland JL. 17α-Estradiol Alleviates Age-related Metabolic and Inflammatory Dysfunction in Male Mice Without Inducing Feminization. J Gerontol A Biol Sci Med Sci 2016; 72:3-15. [PMID: 26809497 PMCID: PMC5155656 DOI: 10.1093/gerona/glv309] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 12/15/2015] [Indexed: 12/20/2022] Open
Abstract
Aging is associated with visceral adiposity, metabolic disorders, and chronic low-grade inflammation. 17α-estradiol (17α-E2), a naturally occurring enantiomer of 17β-estradiol (17β-E2), extends life span in male mice through unresolved mechanisms. We tested whether 17α-E2 could alleviate age-related metabolic dysfunction and inflammation. 17α-E2 reduced body mass, visceral adiposity, and ectopic lipid deposition without decreasing lean mass. These declines were associated with reductions in energy intake due to the activation of hypothalamic anorexigenic pathways and direct effects of 17α-E2 on nutrient-sensing pathways in visceral adipose tissue. 17α-E2 did not alter energy expenditure or excretion. Fasting glucose, insulin, and glycosylated hemoglobin were also reduced by 17α-E2, and hyperinsulinemic-euglycemic clamps revealed improvements in peripheral glucose disposal and hepatic glucose production. Inflammatory mediators in visceral adipose tissue and the circulation were reduced by 17α-E2. 17α-E2 increased AMPKα and reduced mTOR complex 1 activity in visceral adipose tissue but not in liver or quadriceps muscle, which is in contrast to the generalized systemic effects of caloric restriction. These beneficial phenotypic changes occurred in the absence of feminization or cardiac dysfunction, two commonly observed deleterious effects of exogenous estrogen administration. Thus, 17α-E2 holds potential as a novel therapeutic for alleviating age-related metabolic dysfunction through tissue-specific effects.
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Affiliation(s)
- Michael B Stout
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Frederik J Steyn
- Center for Clinical Research and School of Biomedical Sciences, University of Queensland, Herston, Australia
| | - Michael J Jurczak
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pennsylvania
| | | | - Yi Zhu
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - John R Hawse
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| | - Diana Jurk
- Institutes for Cell & Molecular Biosciences and Ageing, Newcastle University
| | - Allyson K Palmer
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Ming Xu
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Tamar Pirtskhalava
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Glenda L Evans
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Roberta de Souza Santos
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Beverly Hills, California
| | - Aaron P Frank
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Beverly Hills, California
| | - Thomas A White
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - David G Monroe
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Ravinder J Singh
- Department of Laboratory Medicine, Mayo Clinic, Rochester, Minnesota
| | | | - Jordan D Miller
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - Deborah J Clegg
- Diabetes and Obesity Research Institute, Cedars-Sinai Medical Center, Beverly Hills, California
| | | | | | - Gerald I Shulman
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut
| | - Tamara Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota
| | - James L Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, Minnesota.
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Fonvig CE, Chabanova E, Ohrt JD, Nielsen LA, Pedersen O, Hansen T, Thomsen HS, Holm JC. Multidisciplinary care of obese children and adolescents for one year reduces ectopic fat content in liver and skeletal muscle. BMC Pediatr 2015; 15:196. [PMID: 26714769 PMCID: PMC4696236 DOI: 10.1186/s12887-015-0513-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 11/24/2015] [Indexed: 02/07/2023] Open
Abstract
Background Ectopic fat deposition in liver and skeletal muscle tissue is related to cardiovascular disease risk and is a common metabolic complication in obese children. We evaluated the hypotheses of ectopic fat in these organs could be diminished following 1 year of multidisciplinary care specialized in childhood obesity, and whether this reduction would associate with changes in other markers of metabolic function. Methods This observational longitudinal study evaluated 40 overweight children and adolescents enrolled in a multidisciplinary treatment protocol at the Children’s Obesity Clinic, Holbæk, Denmark. The participants were assessed by anthropometry, fasting blood samples (HbA1c, glucose, insulin, lipids, and biochemical variables of liver function), and liver and muscle fat content assessed by magnetic resonance spectroscopy at enrollment and following an average of 12.2 months of care. Univariate linear regression models adjusted for age, sex, treatment duration, baseline degree of obesity, and pubertal developmental stage were used for investigating possible associations. Results The standard deviation score (SDS) of baseline median body mass index (BMI) was 2.80 (range: 1.49–3.85) and the median age was 14 years (10–17). At the end of the observational period, the 40 children and adolescents (21 girls) significantly decreased their BMI SDS, liver fat, muscle fat, and visceral adipose tissue volume. The prevalence of hepatic steatosis changed from 28 to 20 % (p = 0.26) and the prevalence of muscular steatosis decreased from 75 to 45 % (p = 0.007). Changes in liver and muscle fat were independent of changes in BMI SDS, baseline degree of obesity, duration of treatment, age, sex, and pubertal developmental stage. Conclusions A 1-year multidisciplinary intervention program in the setting of a childhood obesity outpatient clinic confers a biologically important reduction in liver and muscle fat; metabolic improvements that are independent of the magnitude of concurrent weight loss. Trial registration ClinicalTrials.gov registration number: NCT00928473, the Danish Childhood Obesity Biobank. Registered June 25, 2009. Electronic supplementary material The online version of this article (doi:10.1186/s12887-015-0513-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cilius Esmann Fonvig
- The Children's Obesity Clinic, Department of Pediatrics, Copenhagen University Hospital Holbæk, 4300, Holbæk, Denmark. .,The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Medical and Health Sciences, University of Copenhagen, 2100, Copenhagen Ø, Denmark.
| | - Elizaveta Chabanova
- Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, 2730, Herlev, Denmark.
| | - Johanne Dam Ohrt
- The Children's Obesity Clinic, Department of Pediatrics, Copenhagen University Hospital Holbæk, 4300, Holbæk, Denmark.
| | - Louise Aas Nielsen
- The Children's Obesity Clinic, Department of Pediatrics, Copenhagen University Hospital Holbæk, 4300, Holbæk, Denmark.
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Medical and Health Sciences, University of Copenhagen, 2100, Copenhagen Ø, Denmark.
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Medical and Health Sciences, University of Copenhagen, 2100, Copenhagen Ø, Denmark.
| | - Henrik S Thomsen
- Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, 2730, Herlev, Denmark. .,University of Copenhagen, Faculty of Medical and Health Sciences, 2200, Copenhagen N, Denmark.
| | - Jens-Christian Holm
- The Children's Obesity Clinic, Department of Pediatrics, Copenhagen University Hospital Holbæk, 4300, Holbæk, Denmark. .,University of Copenhagen, Faculty of Medical and Health Sciences, 2200, Copenhagen N, Denmark.
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Abstract
Previous studies have implicated age-associated reductions in mitochondrial oxidative phosphorylation activity in skeletal muscle as a predisposing factor for intramyocellular lipid (IMCL) accumulation and muscle insulin resistance (IR) in the elderly. To further investigate potential alterations in muscle mitochondrial function associated with aging, we assessed basal and insulin-stimulated rates of muscle pyruvate dehydrogenase (VPDH) flux relative to citrate synthase flux (VCS) in healthy lean, elderly subjects and healthy young body mass index- and activity-matched subjects. VPDH/VCS flux was assessed from the (13)C incorporation from of infused [1-13C] glucose into glutamate [4-13C] relative to alanine [3-13C] assessed by LC-tandem MS in muscle biopsies. Insulin-stimulated rates of muscle glucose uptake were reduced by 25% (P<0.01) in the elderly subjects and were associated with ∼70% (P<0.04) increase in IMCL, assessed by 1H magnetic resonance spectroscopy. Basal VPDH/VCS fluxes were similar between the groups (young: 0.20±0.03; elderly: 0.14±0.03) and increased approximately threefold in the young subjects following insulin stimulation. However, this increase was severely blunted in the elderly subjects (young: 0.55±0.04; elderly: 0.18±0.02, P=0.0002) and was associated with an ∼40% (P=0.004) reduction in insulin activation of Akt. These results provide new insights into acquired mitochondrial abnormalities associated with aging and demonstrate that age-associated reductions in muscle mitochondrial function and increased IMCL are associated with a marked inability of mitochondria to switch from lipid to glucose oxidation during insulin stimulation.
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42
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Gao Y, Wu F, Zhou J, Yan L, Jurczak MJ, Lee HY, Yang L, Mueller M, Zhou XB, Dandolo L, Szendroedi J, Roden M, Flannery C, Taylor H, Carmichael GG, Shulman GI, Huang Y. The H19/let-7 double-negative feedback loop contributes to glucose metabolism in muscle cells. Nucleic Acids Res 2014; 42:13799-811. [PMID: 25399420 PMCID: PMC4267628 DOI: 10.1093/nar/gku1160] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The H19 lncRNA has been implicated in development and growth control and is associated with human genetic disorders and cancer. Acting as a molecular sponge, H19 inhibits microRNA (miRNA) let-7. Here we report that H19 is significantly decreased in muscle of human subjects with type-2 diabetes and insulin resistant rodents. This decrease leads to increased bioavailability of let-7, causing diminished expression of let-7 targets, which is recapitulated in vitro where H19 depletion results in impaired insulin signaling and decreased glucose uptake. Furthermore, acute hyperinsulinemia downregulates H19, a phenomenon that occurs through PI3K/AKT-dependent phosphorylation of the miRNA processing factor KSRP, which promotes biogenesis of let-7 and its mediated H19 destabilization. Our results reveal a previously undescribed double-negative feedback loop between sponge lncRNA and target miRNA that contributes to glucose regulation in muscle cells.
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Affiliation(s)
- Yuan Gao
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Gynecology and Obstetrics, Chinese PLA General Hospital, Beijing 100853, P. R. China
| | - Fuju Wu
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Obstetrics and Gynecology, Jilin University, Changchun, Jilin 130021, P. R. China
| | - Jichun Zhou
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Surgical Oncology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, P. R. China
| | - Lei Yan
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Obstetrics and Gynecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250021, P. R. China
| | - Michael J Jurczak
- Howard Hughes Medical Institute and Departments of Internal Medicine, Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Hui-Young Lee
- Howard Hughes Medical Institute and Departments of Internal Medicine, Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Lihua Yang
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Obstetrics and Gynecology Department, Tangshan Gongren Hospital, Tangshan, Hebei 063000, P. R. China
| | - Martin Mueller
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Obstetrics and Gynecology, University Hospital, 3012 Bern, Switzerland
| | - Xiao-Bo Zhou
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA Department of Immunology and Pathogenic Biology, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P. R. China
| | - Luisa Dandolo
- Department of Genetics and Development, Institut Cochin, U1016 Paris, France
| | - Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, 40225 Dusseldorf, Germany Department of Metabolic Diseases, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, 40225 Dusseldorf, Germany Department of Metabolic Diseases, Heinrich Heine University, 40225 Dusseldorf, Germany
| | - Clare Flannery
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Hugh Taylor
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Gordon G Carmichael
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Gerald I Shulman
- Howard Hughes Medical Institute and Departments of Internal Medicine, Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Yingqun Huang
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale Stem Cell Center, Yale University School of Medicine, New Haven, CT 06510, USA
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43
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Affiliation(s)
- Gerald I Shulman
- From the Howard Hughes Medical Institute and the Departments of Internal Medicine and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT
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44
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Wolf P, Winhofer Y, Anderwald CH, Krššák M, Krebs M. Intracellular lipid accumulation and shift during diabetes progression. Wien Med Wochenschr 2014; 164:320-9. [DOI: 10.1007/s10354-014-0292-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/23/2014] [Indexed: 02/08/2023]
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45
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The role of hepatic lipids in hepatic insulin resistance and type 2 diabetes. Nature 2014; 510:84-91. [PMID: 24899308 DOI: 10.1038/nature13478] [Citation(s) in RCA: 800] [Impact Index Per Article: 80.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 03/14/2014] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease and its downstream sequelae, hepatic insulin resistance and type 2 diabetes, are rapidly growing epidemics, which lead to increased morbidity and mortality rates, and soaring health-care costs. Developing interventions requires a comprehensive understanding of the mechanisms by which excess hepatic lipid develops and causes hepatic insulin resistance and type 2 diabetes. Proposed mechanisms implicate various lipid species, inflammatory signalling and other cellular modifications. Studies in mice and humans have elucidated a key role for hepatic diacylglycerol activation of protein kinase Cε in triggering hepatic insulin resistance. Therapeutic approaches based on this mechanism could alleviate the related epidemics of non-alcoholic fatty liver disease and type 2 diabetes.
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Rietman A, Schwarz J, Tomé D, Kok FJ, Mensink M. High dietary protein intake, reducing or eliciting insulin resistance? Eur J Clin Nutr 2014; 68:973-9. [DOI: 10.1038/ejcn.2014.123] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/13/2014] [Accepted: 05/21/2014] [Indexed: 02/07/2023]
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47
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Blaslov K, Bulum T, Zibar K, Duvnjak L. Incretin based therapies: A novel treatment approach for non-alcoholic fatty liver disease. World J Gastroenterol 2014; 20:7356-7365. [PMID: 24966606 PMCID: PMC4064081 DOI: 10.3748/wjg.v20.i23.7356] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 12/07/2013] [Accepted: 01/08/2014] [Indexed: 02/06/2023] Open
Abstract
Non-alcoholic fatty liver disease is considered a hepatic manifestation of metabolic syndrome (MS). The current treatment of non-alcoholic fatty liver disease (NAFLD) principally includes amelioration of MS components by lifestyle modifications but the lack of success in their implementation and sustainment arises the need for effective pharmacological agent in fatty liver treatment. Incretins are gut derived hormones secreted into the circulation in response to nutrient ingestion that enhances glucose-stimulated insulin secretion. Glucagon-like peptide-1 (GLP-1) is the most important incretin. Its receptor agonist and inhibitors of dipeptidyl peptidase-4 (DPP-4) are used in treatment of type 2 diabetes mellitus. DPP-4 serum activity and hepatic expression are shown to be elevated in several hepatic diseases. There are several experimental and clinical trials exploring the efficacy of incretin based therapies in NAFLD treatment. They suggest that GLP-1 analogues might have beneficial effect on hepatic steatosis acting as insulin sensitizers and directly by stimulating GLP-1 receptors expressed on hepatocytes. The use of DPP-4 inhibitors also results in hepatic fat reduction but the mechanism of action remains unclear. There is growing evidence that incretin based therapies have beneficial effects on hepatocytes, however further study analysis are needed to assess the long term effect of incretin based therapies on NAFLD.
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48
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Nassir F, Ibdah JA. Role of mitochondria in nonalcoholic fatty liver disease. Int J Mol Sci 2014; 15:8713-42. [PMID: 24837835 PMCID: PMC4057755 DOI: 10.3390/ijms15058713] [Citation(s) in RCA: 240] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/04/2014] [Accepted: 05/07/2014] [Indexed: 12/15/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) affects about 30% of the general population in the United States and includes a spectrum of disease that includes simple steatosis, non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Significant insight has been gained into our understanding of the pathogenesis of NALFD; however the key metabolic aberrations underlying lipid accumulation in hepatocytes and the progression of NAFLD remain to be elucidated. Accumulating and emerging evidence indicate that hepatic mitochondria play a critical role in the development and pathogenesis of steatosis and NAFLD. Here, we review studies that document a link between the pathogenesis of NAFLD and hepatic mitochondrial dysfunction with particular focus on new insights into the role of impaired fatty acid oxidation, the transcription factor peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and sirtuins in development and progression of NAFLD.
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Affiliation(s)
- Fatiha Nassir
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Missouri, Columbia, MO 65212, USA.
| | - Jamal A Ibdah
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Missouri, Columbia, MO 65212, USA.
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Suga T, Kinugawa S, Takada S, Kadoguchi T, Fukushima A, Homma T, Masaki Y, Furihata T, Takahashi M, Sobirin MA, Ono T, Hirabayashi K, Yokota T, Tanaka S, Okita K, Tsutsui H. Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice. Endocrinology 2014; 155:68-80. [PMID: 24189138 DOI: 10.1210/en.2013-1382] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.
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Affiliation(s)
- Tadashi Suga
- Departments of Cardiovascular Medicine (T.S., S.K., S.Tak., T.K., A.F., T.H., Y.M., T.F., M.T., M.A.S., T.O., K.H., T.Y., H.T.) and Cancer Pathology (S.Tan.), Hokkaido University Graduate School of Medicine, Hokkaido 060-8638, Japan; Faculty of Sport and Health Science (T.S.), Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan; Research Fellow of the Japan Society for the Promotion of Science (S.Tak.); and Graduate School of Program in Lifelong Learning Studies (K.O.), Hokusho University, Hokkaido 069-8511, Japan
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Ye Q, Danzer CF, Fuchs A, Vats D, Wolfrum C, Rudin M. Longitudinal evaluation of hepatic lipid deposition and composition in ob/ob and ob/+ control mice. NMR IN BIOMEDICINE 2013; 26:1079-1088. [PMID: 23355481 DOI: 10.1002/nbm.2921] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 11/05/2012] [Accepted: 12/17/2012] [Indexed: 06/01/2023]
Abstract
Obesity is associated with insulin resistance (IR) and hepatosteatosis. Understanding the link between IR and hepatosteatosis could be relevant to chronic clinical outcomes. The objective of this study was to quantitatively assess lipid deposition (fractional lipid mass, fLM) and composition (fraction of polyunsaturated lipids, fPUL and mean chain length, MCL) in livers of ob/ob mice, a genetic model of obesity and mild diabetes, and ob/+ heterozygous control animals in a noninvasive manner using (1) H-MRS at 9.4T. For accurate quantification, intensity values were corrected for differences in T2 values while T1 effects were considered minimal due to the long TR values used. Values of fLM, fPUL and MCL were derived from T2 -corrected signal intensities of lipids and water resonance. Hepatic lipid signals were compared with fasted plasma insulin, glucose and lipid levels. Statistically significant correlations between fPUL and fasting plasma insulin/glucose levels were found in adolescent ob/ob mice. A similar correlation was found between fLM and fasting plasma insulin levels; however, the correlation between fLM and fasting plasma glucose levels was less obvious in adolescent ob/ob mice. These correlations were lost in adult ob/ob mice. The study showed that in adolescent ob/ob mice, there was an obvious link between lipid deposition/composition in the liver and plasma insulin/glucose levels. This correlation was lost in adult animals, probably due to the limited lipid storage capacity of the liver.
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Affiliation(s)
- Qiong Ye
- Institute for Biomedical Engineering, ETH Zürich and University of Zürich, Switzerland
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