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Risikesan J, Nellemann B, Christensen B, Jørgensen JOL, Nielsen S. No effect of 10 weeks erythropoietin treatment on lipid oxidation in healthy men. Endocr Connect 2020; 9:1148-1155. [PMID: 33112835 PMCID: PMC7774772 DOI: 10.1530/ec-20-0305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/13/2020] [Indexed: 11/21/2022]
Abstract
Studies indicate that erythropoietin (EPO) has effect on lipid and energy metabolism; however, the impact of EPO on lipid oxidation in vivo has not been well documented. Here, we evaluate whether long-term erythropoiesis-stimulating agent (ESA) treatment affects the oxidation of plasma very low-density lipoprotein triglycerides (VLDL-TG) fatty acids (FA), plasma free fatty acids (FFA) and non-plasma (residual) FA in healthy, young, sedentary men. Infusion of [1-14C]VLDL-TG and [9,10-3H]palmitate was used in combination with indirect calorimetry to assess resting lipid fuel utilization and kinetics, and resting energy expenditure (REE) before and after 10 weeks of ESA exposure compared with placebo. REE increased significantly during ESA compared with placebo (P = 0.023, RM-ANOVA). Oxidation rates of VLDL-TG FA, FFA, and residual FA remained unchanged during ESA compared with placebo. The relative contribution of the lipid stores was greatest for FFA (47.1%) and the total lipid oxidation rate and was not significantly different between ESA and placebo-treated subjects. We conclude that long-term ESA treatment of healthy young men increases REE but does not alter the oxidation rates of plasma and non-plasma FA sources.
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Affiliation(s)
- Jeyanthini Risikesan
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Correspondence should be addressed to S Nielsen:
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2
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Valsdottir TD, Henriksen C, Odden N, Nellemann B, Jeppesen PB, Hisdal J, Westerberg AC, Jensen J. Effect of a Low-Carbohydrate High-Fat Diet and a Single Bout of Exercise on Glucose Tolerance, Lipid Profile and Endothelial Function in Normal Weight Young Healthy Females. Front Physiol 2019; 10:1499. [PMID: 31920704 PMCID: PMC6931312 DOI: 10.3389/fphys.2019.01499] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/25/2019] [Indexed: 01/07/2023] Open
Abstract
Low-carbohydrate-high-fat (LCHF) diets are efficient for weight loss, and are also used by healthy people to maintain bodyweight. The main aim of this study was to investigate the effect of 3-week energy-balanced LCHF-diet, with >75 percentage energy (E%) from fat, on glucose tolerance and lipid profile in normal weight, young, healthy women. The second aim of the study was to investigate if a bout of exercise would prevent any negative effect of LCHF-diet on glucose tolerance. Seventeen females participated, age 23.5 ± 0.5 years; body mass index 21.0 ± 0.4 kg/m2, with a mean dietary intake of 78 ± 1 E% fat, 19 ± 1 E% protein and 3 ± 0 E% carbohydrates. Measurements were performed at baseline and post-intervention. Fasting glucose decreased from 4.7 ± 0.1 to 4.4 mmol/L (p < 0.001) during the dietary intervention whereas fasting insulin was unaffected. Glucose area under the curve (AUC) and insulin AUC did not change during an OGTT after the intervention. Before the intervention, a bout of aerobic exercise reduced fasting glucose (4.4 ± 0.1 mmol/L, p < 0.001) and glucose AUC (739 ± 41 to 661 ± 25, p = 0.008) during OGTT the following morning. After the intervention, exercise did not reduce fasting glucose the following morning, and glucose AUC during an OGTT increased compared to the day before (789 ± 43 to 889 ± 40 mmol/L∙120min–1, p = 0.001). AUC for insulin was unaffected. The dietary intervention increased total cholesterol (p < 0.001), low-density lipoprotein (p ≤ 0.001), high-density lipoprotein (p = 0.011), triglycerides (p = 0.035), and free fatty acids (p = 0.021). In conclusion, 3-week LCHF-diet reduced fasting glucose, while glucose tolerance was unaffected. A bout of exercise post-intervention did not decrease AUC glucose as it did at baseline. Total cholesterol increased, mainly due to increments in low-density lipoprotein. LCHF-diets should be further evaluated and carefully considered for healthy individuals.
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Affiliation(s)
- Thorhildur Ditta Valsdottir
- Department of Medicine, Atlantis Medical University College, Oslo, Norway.,Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Christine Henriksen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Nancy Odden
- Department of Nutrition, Atlantis Medical University College, Oslo, Norway
| | - Birgitte Nellemann
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Per B Jeppesen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jonny Hisdal
- Oslo Vascular Center, Department of Vascular Surgery, Oslo University Hospital, Oslo, Norway
| | - Ane C Westerberg
- Department of Nutrition, Atlantis Medical University College, Oslo, Norway.,Institute of Health Sciences, Kristiania University College, Oslo, Norway
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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3
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Sharma VM, Vestergaard ET, Jessen N, Kolind-Thomsen P, Nellemann B, Nielsen TS, Vendelbo MH, Møller N, Sharma R, Lee KY, Kopchick JJ, Jørgensen JOL, Puri V. Growth hormone acts along the PPARγ-FSP27 axis to stimulate lipolysis in human adipocytes. Am J Physiol Endocrinol Metab 2019; 316:E34-E42. [PMID: 30325658 PMCID: PMC6417689 DOI: 10.1152/ajpendo.00129.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 10/01/2018] [Accepted: 10/03/2018] [Indexed: 12/22/2022]
Abstract
The lipolytic effects of growth hormone (GH) have been known for half a century and play an important physiological role for substrate metabolism during fasting. In addition, sustained GH-induced lipolysis is causally linked to insulin resistance. However, the underlying molecular mechanisms remain elusive. In the present study, we obtained experimental data in human subjects and used human adipose-derived stromal vascular cells (hADSCs) as a model system to elucidate GH-triggered molecular signaling that stimulates adipose tissue lipolysis and insulin resistance in human adipocytes. We discovered that GH downregulates the expression of fat-specific protein (FSP27), a negative regulator of lipolysis, by impairing the transcriptional ability of the master transcriptional regulator, peroxisome proliferator-activated receptor-γ (PPARγ) via MEK/ERK activation. Ultimately, GH treatment promotes phosphorylation of PPARγ at Ser273 and causes its translocation from nucleus to the cytosol. Surprisingly, FSP27 overexpression inhibited PPARγ Ser273 phosphorylation and promoted its nuclear retention. GH antagonist treatment had similar effects. Our study identifies a novel signaling mechanism by which GH transcriptionally induces lipolysis via the MEK/ERK pathway that acts along PPARγ-FSP27 in human adipose tissue.
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Affiliation(s)
- Vishva M Sharma
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
- The Diabetes Institute, Ohio University , Athens, Ohio
| | - Esben Thyssen Vestergaard
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Department of Pediatrics, Randers Regional Hospital, Randers, Denmark
| | - Niels Jessen
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Research Laboratory for Biochemical Pathology, Aarhus University Hospital , Aarhus , Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Peter Kolind-Thomsen
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Research Laboratory for Biochemical Pathology, Aarhus University Hospital , Aarhus , Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | | | - Thomas S Nielsen
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Faculty of Health and Medical Sciences, The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen , Copenhagen , Denmark
| | - Mikkel Holm Vendelbo
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital , Aarhus , Denmark
| | - Niels Møller
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Rita Sharma
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
- The Diabetes Institute, Ohio University , Athens, Ohio
| | - Kevin Y Lee
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
- The Diabetes Institute, Ohio University , Athens, Ohio
| | - John J Kopchick
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
- The Diabetes Institute, Ohio University , Athens, Ohio
- Edison Biotechnology Institute, Ohio University , Athens, Ohio
| | - Jens Otto Lunde Jørgensen
- Medical Research Laboratory, Aarhus University , Aarhus , Denmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Vishwajeet Puri
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, Ohio
- The Diabetes Institute, Ohio University , Athens, Ohio
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4
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Riis S, Christensen B, Nellemann B, Møller AB, Husted AS, Pedersen SB, Schwartz TW, Jørgensen JOL, Jessen N. Molecular adaptations in human subcutaneous adipose tissue after ten weeks of endurance exercise training in healthy males. J Appl Physiol (1985) 2018; 126:569-577. [PMID: 30571288 DOI: 10.1152/japplphysiol.00989.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Endurance exercise training induces adaptations in metabolically active organs, but adaptations in human subcutaneous adipose tissue (scAT) remains incompletely understood. On the basis of animal studies, we hypothesized that endurance exercise training would increase the expression of proteins involved in lipolysis and glucose uptake in scAT. To test these hypotheses, 19 young and healthy males were randomized to either endurance exercise training (TR; age 18-24 yr; BMI 19.0-25.4 kg/m2) or a nonexercising control group (CON; age 21-35 yr; BMI 20.5-28.8 kg/m2). Abdominal subcutaneous fat biopsies and blood were obtained at rest before and after intervention. By using Western blotting and PCR, we determined expression of lipid droplet-associated proteins, various proteins involved in substrate metabolism, and mRNA abundance of cell surface G protein-coupled receptors (GPCRs). Adipose tissue insulin sensitivity was determined from fasting plasma insulin and nonesterified fatty acids (adipose tissue insulin resistance index; Adipo-IR). Adipo-IR improved in TR compared with CON ( P = 0.03). This was accompanied by increased insulin receptor (IR) protein expression in scAT with a 1.54-fold (SD 0.79) change from baseline in TR vs. 0.85 (SD 0.30) in CON ( P = 0.007). Additionally, hexokinase II (HKII) and succinate dehydrogenase complex subunit A (SDHA) protein increased in TR compared with CON ( P = 0.006 and P = 0.04, respectively). We did not observe changes in lipid droplet-associated proteins or mRNA abundance of GPCRs. Collectively, 10 weeks of endurance exercise training improved adipose tissue insulin sensitivity, which was accompanied by increased IR, HKII, and SDHA protein expression in scAT. We suggest that these adaptations contribute to an improved metabolic flexibility. NEW & NOTEWORTHY This study is the first to investigate the molecular adaptations in human subcutaneous adipose tissue (scAT) after endurance exercise training compared with a nonexercising control group. We show that endurance exercise training improves insulin sensitivity in human scAT, and this is accompanied by increased expression of insulin receptor, hexokinase II, and succinate dehydrogenase complex subunit A. Collectively, our data suggest that endurance exercise training induces molecular adaptations in human scAT, which may contribute to an improved metabolic flexibility.
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Affiliation(s)
- Simon Riis
- Section for Sport Science, Department of Public Health, Aarhus University , Aarhus , Denmark.,Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University , Aarhus , Denmark
| | - Britt Christensen
- Section for Sport Science, Department of Public Health, Aarhus University , Aarhus , Denmark.,Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University , Aarhus , Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital , Aarhus , Denmark
| | - Anna Sofie Husted
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research , Copenhagen , Denmark
| | - Steen B Pedersen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital , Aarhus , Denmark
| | - Thue W Schwartz
- Section for Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research , Copenhagen , Denmark.,Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen , Copenhagen , Denmark
| | | | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Department of Clinical Medicine, Aarhus University , Aarhus , Denmark.,Department of Biomedicine, Aarhus University , Aarhus , Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital , Aarhus , Denmark
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5
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Sollie O, Jeppesen PB, Tangen DS, Jernerén F, Nellemann B, Valsdottir D, Madsen K, Turner C, Refsum H, Skålhegg BS, Ivy JL, Jensen J. Protein intake in the early recovery period after exhaustive exercise improves performance the following day. J Appl Physiol (1985) 2018; 125:1731-1742. [DOI: 10.1152/japplphysiol.01132.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of the present study was to investigate the effect of protein and carbohydrate ingestion during early recovery from exhaustive exercise on performance after 18-h recovery. Eight elite cyclists (V̇o2max: 74.0 ± 1.6 ml·kg−1·min−1) completed two exercise and diet interventions in a double-blinded, randomized, crossover design. Participants cycled first at 73% of V̇o2max (W73%) followed by 1-min intervals at 90% of V̇o2max until exhaustion. During the first 2 h of recovery, participants ingested either 1.2 g carbohydrate·kg−1·h−1 (CHO) or 0.8 g carbohydrate + 0.4 g protein·kg−1·h−1 (CHO + PROT). The diet during the remaining recovery period was similar for both interventions and adjusted to body weight. After an 18-h recovery, cycling performance was assessed with a 10-s sprint test, 30 min of cycling at W73%, and a cycling time trial (TT). The TT was 8.5% faster (41:53 ± 1:51 vs. 45:26 ± 1:32 min; P < 0.03) after CHO + PROT compared with CHO. Mean power output during the sprints was 3.7% higher in CHO + PROT compared with CHO (1,063 ± 54 vs. 1,026 ± 53 W; P = 0.01). Nitrogen balance in the recovery period was negative in CHO and neutral in CHO + PROT (−82.4 ± 11.5 vs. 7.0 ± 15.4 mg/kg; P < 0.01). In conclusion, TT and sprint performances were improved 18 h after exhaustive cycling by CHO + PROT supplementation during the first 2 h of recovery compared with isoenergetic CHO supplementation. Our results indicate that intake of carbohydrate plus protein after exhaustive endurance exercise more rapidly converts the body from a catabolic to an anabolic state than carbohydrate alone, thus speeding recovery and improving subsequent cycling performance. NEW & NOTEWORTHY Prolonged high intensity endurance exercise depends on glycogen utilization and high oxidative capacity. Still, exhaustion develops and effective recovery strategies are required to compete in multiday stage races. We show that coingestion of protein and carbohydrate during the first 2 h of recovery is superior to isoenergetic intake of carbohydrate to stimulate recovery, and improves both endurance time-trial and 10-s sprint performance the following day in elite cyclists.
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Affiliation(s)
- Ove Sollie
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
| | - Per B. Jeppesen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Daniel S. Tangen
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
| | - Fredrik Jernerén
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Birgitte Nellemann
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
| | - Ditta Valsdottir
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
- Department of Medical Sciences, Atlantis Medical University College, Oslo, Norway
| | - Klavs Madsen
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
- Department of Public Health–Sport Science, Aarhus University, Aarhus, Norway
| | - Cheryl Turner
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Helga Refsum
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
- Department of Nutrition, Section for Molecular Nutrition, University of Oslo, Oslo, Norway
| | - Bjørn S. Skålhegg
- Department of Nutrition, Section for Molecular Nutrition, University of Oslo, Oslo, Norway
| | - John L. Ivy
- Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
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Poulsen MK, Nellemann B, Bibby BM, Stødkilde-Jørgensen H, Pedersen SB, Grønbaek H, Nielsen S. No effect of resveratrol on VLDL-TG kinetics and insulin sensitivity in obese men with nonalcoholic fatty liver disease. Diabetes Obes Metab 2018; 20:2504-2509. [PMID: 29885082 DOI: 10.1111/dom.13409] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 06/02/2018] [Accepted: 06/05/2018] [Indexed: 12/19/2022]
Abstract
The present study (NCT01446276, ClinicalTrials.gov) assessed long-term effects of high-dose Resveratrol (RSV) on basal and insulin-mediated very low-density lipoprotein triglyceride (VLDL-TG), palmitate and glucose kinetics, and liver fat content in men with nonalcoholic fatty liver disease (NAFLD). Participants (n = 16) were non-diabetic, upper-body obese (BMI > 28 kg/m2 , WHR > 0.9) men with NAFLD who were randomized (1:1) in a double-blinded, placebo-controlled clinical trial to either RSV or placebo (500 mg 3 times daily) for 6 months. Magnetic resonance (MR) spectroscopy, dual-X-ray absorptiometry and MR imaging assessed liver fat content and body composition, respectively. 14 C-labeled VLDL-TG and 3 H-labeled glucose and palmitate tracers, in combination with indirect calorimetry and breath samples, were used to assess kinetics and substrate oxidations during basal and hyperinsulinaemic euglycaemic clamp conditions. RSV did not improve either basal or insulin-mediated VLDL-TG secretion, oxidation or clearance rates, nor did it affect palmitate or glucose turnover. Likewise, no changes in body composition or liver fat content occurred following RSV compared with placebo treatment. Therefore, RSV cannot be recommended for treatment of metabolic abnormalities in NAFLD.
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Affiliation(s)
- Marianne K Poulsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Bo Martin Bibby
- Department of Public Health, Aarhus University, Aarhus, Denmark
| | | | - Steen B Pedersen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Henning Grønbaek
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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7
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Nielsen J, Christensen AE, Nellemann B, Christensen B. Lipid droplet size and location in human skeletal muscle fibers are associated with insulin sensitivity. Am J Physiol Endocrinol Metab 2017; 313:E721-E730. [PMID: 28743757 DOI: 10.1152/ajpendo.00062.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/28/2017] [Accepted: 07/18/2017] [Indexed: 11/22/2022]
Abstract
In skeletal muscle, an accumulation of lipid droplets (LDs) in the subsarcolemmal space is associated with insulin resistance, but the underlying mechanism is not clear. We aimed to investigate how the size, number, and location of LDs are associated with insulin sensitivity and muscle fiber types and are regulated by aerobic training and treatment with an erythropoiesis-stimulating agent (ESA) in healthy young untrained men. LD analyses were performed by quantitative transmission electron microscopy, and insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp. At baseline, we found that only the diameter (and not the number) of individual subsarcolemmal LDs was negatively associated with insulin sensitivity (R2 = 0.20, P = 0.03, n = 29). Despite 34% (P = 0.004) fewer LDs, the diameter of individual subsarcolemmal LDs was 20% (P = 0.0004) larger in type 2 fibers than in type 1 fibers. Furthermore, aerobic training decreased the size of subsarcolemmal LDs in the type 2 fibers, and ESA treatment lowered the number of both intermyofibrillar and subsarcolemmal LDs in the type 1 fibers. In conclusion, the size of individual subsarcolemmal LDs may be involved in the mechanism by which LDs are associated with insulin resistance in skeletal muscle.
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Affiliation(s)
- Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense M, Denmark;
- Department of Pathology, SDU Muscle Research Cluster (SMRC), Odense University Hospital, Odense C, Denmark; and
| | - Anders E Christensen
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense M, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
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8
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Andersen IR, Søndergaard E, Sørensen LP, Nellemann B, Gormsen LC, Jensen MD, Nielsen S. Increased VLDL-TG Fatty Acid Storage in Skeletal Muscle in Men With Type 2 Diabetes. J Clin Endocrinol Metab 2017; 102:831-839. [PMID: 27898284 DOI: 10.1210/jc.2016-2979] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/28/2016] [Indexed: 12/19/2022]
Abstract
CONTEXT Lipoprotein lipase (LPL) activity is considered the rate-limiting step of very-low-density-lipoprotein triglycerides (VLDL-TG) tissue storage, and has been suggested to relate to the development of obesity as well as insulin resistance and type 2 diabetes. OBJECTIVE The objective of the study was to assess the relationship between the quantitative storage of VLDL-TG fatty acids and LPL activity and other storage factors in muscle and adipose tissue. In addition, we examine whether such relations were influenced by type 2 diabetes. DESIGN We recruited 23 men (12 with type 2 diabetes, 11 nondiabetic) matched for age and body mass index. Postabsorptive VLDL-TG muscle and subcutaneous adipose tissue (abdominal and leg) quantitative storage was measured using tissue biopsies in combination with a primed-constant infusion of ex vivo triolein labeled [1-14C]VLDL-TG and a bolus infusion of ex vivo triolein labeled [9,10-3H]VLDL-TG. Biopsies were analyzed for LPL activity and cellular storage factors. RESULTS VLDL-TG storage rate was significantly greater in men with type 2 diabetes compared with nondiabetic men in muscle tissue (P = 0.02). We found no significant relationship between VLDL-TG storage rate and LPL activity or other storage factors in muscle or adipose tissue. However, LPL activity correlated with fractional VLDL-TG storage in abdominal fat (P = 0.04). CONCLUSIONS Men with type 2 diabetes have increased VLDL-TG storage in muscle tissue, potentially contributing to increased intramyocellular triglyceride and ectopic lipid deposition. Neither muscle nor adipose tissue storage rates were related to LPL activity. This argues against LPL as a rate-limiting step in the postabsorptive quantitative storage of VLDL-TG.
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Affiliation(s)
| | - Esben Søndergaard
- Departments of Endocrinology and Internal Medicine and
- Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905; and
- Danish Diabetes Academy, 5000 Odense, Denmark
| | | | | | - Lars C Gormsen
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, 8000 Aarhus, Denmark
| | - Michael D Jensen
- Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905; and
| | - Søren Nielsen
- Departments of Endocrinology and Internal Medicine and
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9
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Langleite TM, Jensen J, Norheim F, Gulseth HL, Tangen DS, Kolnes KJ, Heck A, Storås T, Grøthe G, Dahl MA, Kielland A, Holen T, Noreng HJ, Stadheim HK, Bjørnerud A, Johansen EI, Nellemann B, Birkeland KI, Drevon CA. Insulin sensitivity, body composition and adipose depots following 12 w combined endurance and strength training in dysglycemic and normoglycemic sedentary men. Arch Physiol Biochem 2016; 122:167-179. [PMID: 27477619 DOI: 10.1080/13813455.2016.1202985] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
CONTEXT Insulin resistance and dysglycemia are associated with physical inactivity and adiposity, and may be improved by exercise. OBJECTIVE Investigate the effect of exercise on insulin sensitivity, body composition and adipose depots in sedentary men with (n = 11) or without (n = 11) overweight and dysglycemia. MATERIAL AND METHODS Euglycemic-hyperinsulinemic clamp, ankle-to-neck MRI, MRS, muscle and adipose tissue biopsies before and after 12 weeks combined strength and endurance exercise. RESULTS Insulin sensitivity, VO2max, strength, whole-body and muscle fat content, and abdominal adipose depots were improved without obvious differences between normo- and dysglycemic men. Hepatic fat, waist circumference and subcutaneous adipose tissue were reduced in the dysglycemic group. For both groups plasma adiponectin was reduced, whereas IL-6 was unchanged. Visceral fat was preferentially lost compared with other adipose depots. DISCUSSION AND CONCLUSION Body composition, fat distribution and insulin sensitivity improved following training in sedentary middle-aged men with and without dysglycemia.
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Affiliation(s)
- Torgrim Mikal Langleite
- a Department of Nutrition , University of Oslo , Oslo , Norway
- b Department of Endocrinology , Morbid Obesity and Preventive Medicine, Oslo University Hospital , Oslo , Norway
| | - Jørgen Jensen
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | - Frode Norheim
- a Department of Nutrition , University of Oslo , Oslo , Norway
| | - Hanne Løvdal Gulseth
- b Department of Endocrinology , Morbid Obesity and Preventive Medicine, Oslo University Hospital , Oslo , Norway
| | - Daniel Steensen Tangen
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | | | - Ansgar Heck
- b Department of Endocrinology , Morbid Obesity and Preventive Medicine, Oslo University Hospital , Oslo , Norway
- d Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
| | - Tryggve Storås
- e The Intervention Centre, Oslo University Hospital , Oslo , Norway
| | - Guro Grøthe
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | - Marius Adler Dahl
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | - Anders Kielland
- a Department of Nutrition , University of Oslo , Oslo , Norway
| | - Torgeir Holen
- a Department of Nutrition , University of Oslo , Oslo , Norway
| | | | - Hans Kristian Stadheim
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | - Atle Bjørnerud
- e The Intervention Centre, Oslo University Hospital , Oslo , Norway
- g Department of Physics , University of Oslo , Oslo , Norway , and
| | - Egil Ivar Johansen
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
| | - Birgitte Nellemann
- c Department of Physical Performance , Norwegian School of Sport Sciences , Oslo , Norway
- h Department of Endocrinology and Internal Medicine , Aarhus University Hospital , Aarhus , Denmark
| | - Kåre Inge Birkeland
- b Department of Endocrinology , Morbid Obesity and Preventive Medicine, Oslo University Hospital , Oslo , Norway
- d Institute of Clinical Medicine, Faculty of Medicine, University of Oslo , Oslo , Norway
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Christensen B, Nellemann B, Jørgensen JOL, Pedersen SB, Jessen N. Erythropoietin does not activate erythropoietin receptor signaling or lipolytic pathways in human subcutaneous white adipose tissue in vivo. Lipids Health Dis 2016; 15:160. [PMID: 27640183 PMCID: PMC5027120 DOI: 10.1186/s12944-016-0327-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/06/2016] [Indexed: 01/01/2023] Open
Abstract
Background Erythropoietin (Epo) exerts direct effects on white adipose tissue (WAT) in mice in addition to its erythropoietic effects, and in humans Epo increases resting energy expenditure and affect serum lipid levels, but direct effects of Epo in human WAT have not been documented. We therefore investigated the effects of acute and prolonged Epo exposure on human WAT in vivo. Method Data were obtained from two clinical trials: 1) acute Epo exposure (rHuEpo, 400 IU/kg) followed by WAT biopsies after 1 h and 2) 10 weeks treatment with the erythropoiesis-stimulating agent (ESA) Darbepoietin-alpha. Biopsies were analyzed by PCR for Epo receptor (Epo-R) mRNA. A new and highly specific antibody (A82, Amgen) was used to evaluate the presence of Epo-R by western blot analysis in addition to Epo-R signaling proteins (Akt, STAT5, p70s6k, LYN, and p38MAPK), activation of lipolytic pathways (ATGL, HSL, CGI-58, G0S2, Perilipin, Cidea, Cidec, AMPK, and ACC), and mitochondrial biogenesis (VDAC, HSP90, PDH, and SDHA). Results No evidence of in vivo activation of the Epo-R in WAT could be documented despite detectable levels of Epo-R mRNA. Conclusion Thus, in contradiction to animal studies, Epo treatment within a physiological relevant range in humans does not exert direct effects in a subcutaneous WAT.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark. .,Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Jens Otto L Jørgensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Steen B Pedersen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
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Sieljacks P, Thams L, Nellemann B, Larsen MS, Vissing K, Christensen B. Comparative Effects of Aerobic Training and Erythropoietin on Oxygen Uptake in Untrained Humans. J Strength Cond Res 2016; 30:2307-17. [DOI: 10.1519/jsc.0000000000001314] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Poulsen MK, Nellemann B, Stødkilde-Jørgensen H, Pedersen SB, Grønbæk H, Nielsen S. Impaired Insulin Suppression of VLDL-Triglyceride Kinetics in Nonalcoholic Fatty Liver Disease. J Clin Endocrinol Metab 2016; 101:1637-46. [PMID: 26829441 DOI: 10.1210/jc.2015-3476] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT Nonalcoholic fatty liver disease (NAFLD) is associated with glucose and lipid metabolic abnormalities. However, insulin suppression of very low-density lipoprotein-triglyceride (VLDL-TG) kinetics is not fully understood. OBJECTIVE The objective of the study was to determine VLDL-TG, glucose, and palmitate kinetics during fasting and hyperinsulinemia in men with (NAFLD+) and without NAFLD (NAFLD−). DESIGN Twenty-seven nondiabetic, upper-body obese (waist to hip ratio > 0.9, body mass index > 28 kg/m2) men, 18 NAFLD+, and nine NAFLD− determined by magnetic resonance spectroscopy were enrolled.14C-labeled VLDL-TG and 3H-labeled glucose and palmitate tracers were applied in combination with indirect calorimetry and breath samples to assess kinetics and substrate oxidations postabsorptively and during a hyperinsulinemic-euglycemic clamp. Dual-X-ray absorptiometry and magnetic resonance imaging assessed body composition. RESULTS Liver fat content was greater in NAFLD+ than NAFLD− men (21.0% vs 3.7%), even though body composition, metabolites (except triglycerides), and insulin were similar in the groups. Insulin suppression of VLDL-TG secretion (P = .0001), oxidation (P = .0003), and concentration (P= .008) as well as percentage decreases were lower in NAFLD+ than NAFLD− men (secretion: 31.9% ± 17.2% vs 64.7% ± 19.9%; oxidation: −9.0% ± 24.7% vs 46.5% ± 36.6%; concentration: 11.9% ± 20.7% vs 56.2% ± 22.9%, all P < .001). Likewise, lower insulin suppression of very low-density lipoprotein particle size was present in NAFLD+ than NAFLD− men (P = .0002). Conversely, insulin suppression of endogenous glucose production was similar in the groups. CONCLUSIONS Compared with endogenous glucose production, the inability of NAFLD+ men to suppress VLDL-TG kinetics to compensate for the increased liver fat content seems to be an early pathophysiological manifestation of male NAFLD+. These data suggest therapeutic targets reducing liver fat content may ameliorate metabolic abnormalities associated with NAFLD and presumably diabetes.
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Affiliation(s)
- Marianne K Poulsen
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
| | - Birgitte Nellemann
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
| | - Hans Stødkilde-Jørgensen
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
| | - Steen B Pedersen
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
| | - Henning Grønbæk
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
| | - Søren Nielsen
- Departments of Endocrinology and Internal Medicine (M.K.P., B.N., S.B.P., S.N.) and Hepatology and Gastroenterology (H.G.), Aarhus University Hospital, 8000 C Aarhus, Denmark; and The MR Research Centre (H.S.-J.), Aarhus University Hospital, 8200 N Skejby, Denmark
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Hoedt A, Christensen B, Nellemann B, Mikkelsen UR, Hansen M, Schjerling P, Farup J. Satellite cell response to erythropoietin treatment and endurance training in healthy young men. J Physiol 2015; 594:727-43. [PMID: 26607845 DOI: 10.1113/jp271333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/18/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINT Erythropoietin (Epo) treatment may induce myogenic differentiation factor (MyoD) expression and prevent apoptosis in satellite cells (SCs) in murine and in vitro models. Endurance training stimulates SC proliferation in vivo in murine and human skeletal muscle. In the present study, we show, in human skeletal muscle, that treatment with an Epo-stimulating agent (darbepoetin-α) in vivo increases the content of MyoD(+) SCs in healthy young men. Moreover, we report that Epo receptor mRNA is expressed in adult human SCs, suggesting that Epo may directly target SCs through ligand-receptor interaction. Moreover, endurance training, but not Epo treatment, increases the SC content in type II myofibres, as well as the content of MyoD(+) SCs. Collectively, our results suggest that Epo treatment can regulate human SCs in vivo, supported by Epo receptor mRNA expression in human SCs. In effect, long-term Epo treatment during disease conditions involving anaemia may impact SCs and warrants further investigation. Satellite cell (SC) proliferation is observed following erythropoitin treatment in vitro in murine myoblasts and endurance training in vivo in human skeletal muscle. The present study aimed to investigate the effects of prolonged erythropoiesis-stimulating agent (ESA; darbepoetin-α) treatment and endurance training, separately and combined, on SC quantity and commitment in human skeletal muscle. Thirty-five healthy, untrained men were randomized into four groups: sedentary-placebo (SP, n = 9), sedentary-ESA (SE, n = 9), training-placebo (TP, n = 9) or training-ESA (TE, n = 8). ESA/placebo was injected once weekly and training consisted of ergometer cycling three times a week for 10 weeks. Prior to and following the intervention period, blood samples and muscle biopsies were obtained and maximal oxygen uptake (V̇O2, max) was measured. Immunohistochemical analyses were used to quantify fibre type specific SCs (Pax7(+)), myonuclei and active SCs (Pax7(+)/MyoD(+)). ESA treatment led to elevated haematocrit, whereas endurance training increased V̇O2, max. Endurance training led to an increase in SCs associated with type II fibres (P < 0.05), whereas type I fibres showed no changes. Both ESA treatment and endurance training increased Pax7(+)/MyoD(+) cells, whereas only ESA treatment increased the total content of MyoD(+) cells. Epo-R mRNA presence in adult SC was tested with real-time RT-PCR using fluorescence-activated cell sorting (CD56(+)/CD45(-)/CD31(-)) to isolate cells from a human rectus abdominis muscle and was found to be considerably higher than in whole muscle. In conclusion, endurance training and ESA treatment may separately stimulate SC commitment to the myogenic program. Furthermore, ESA-treatment may alter SC activity by direct interaction with the Epo-R expressed on SCs.
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Affiliation(s)
- Andrea Hoedt
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Ramer Mikkelsen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.,Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Hansen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jean Farup
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
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Søndergaard E, Nellemann B, Sørensen LP, Christensen B, Gormsen LC, Nielsen S. Lean body mass, not FFA, predicts VLDL-TG secretion rate in healthy men. Obesity (Silver Spring) 2015; 23:1379-85. [PMID: 26052691 DOI: 10.1002/oby.21108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/10/2015] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Triglyceride is a risk factor for cardiovascular disease. However, the impact of body composition and free fatty acid (FFA) levels on very-low-density-lipoprotein triglyceride (VLDL-TG) secretion remains controversial. The aim was to identify predictors of VLDL-TG secretion in a data set compiled from seven previously published studies. METHODS VLDL-TG kinetics was studied in 96 healthy men covering a wide span in body composition. A primed-constant infusion of ex vivo labeled [1-(14)C]-triolein VLDL-TG was used. Body composition was determined by dual X-ray absorptiometry and computed tomography scanning. Energy expenditure was measured by indirect calorimetry. Palmitate flux was measured by a [9,10-(3)H]-palmitate infusion. RESULTS VLDL-TG secretion rate correlated significantly with body mass index (BMI), lean body mass (LBM), total fat mass, resting energy expenditure (REE), and insulin. A trend toward an inverse relationship between VLDL-TG secretion rate and FFA concentration was observed. In mixed model linear regression analysis, VLDL-TG secretion rate was positively associated with LBM (P = 0.03), and VLDL-TG clearance rate was inversely related to total fat mass (P < 0.01). CONCLUSIONS LBM is a predictor of VLDL-TG secretion in healthy men, whereas FFA availability is not associated with VLDL-TG secretion. The work suggests reporting VLDL-TG secretion rates normalized for LBM when comparing subjects with differences in body composition.
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Affiliation(s)
- Esben Søndergaard
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Danish Diabetes Academy, Odense, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Lars Peter Sørensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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15
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Christensen B, Nellemann B, Thorsen K, Nielsen MM, Pedersen SB, Ornstrup MJ, JØrgensen JOL, Jessen N. Prolonged erythropoietin treatment does not impact gene expression in human skeletal muscle. Muscle Nerve 2015; 51:554-61. [PMID: 25088500 DOI: 10.1002/mus.24355] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2014] [Indexed: 01/12/2023]
Abstract
INTRODUCTION We tested for the presence of erythropoietin receptor (Epo-R) in human skeletal muscle and alterations in gene expression after prolonged use of an erythropoiesis-stimulating agent (ESA). METHODS Nine healthy men were treated with ESA for 10 weeks (darbepoietin alfa). Muscle biopsies were collected before and after treatment. Alterations in gene expression were evaluated by gene array. Western blot and PCR analysis were used to test for Epo-R presence in human skeletal muscle. RESULTS Very low Epo-R mRNA levels were found, but a new and sensitive antibody did not identify Epo-R protein in human skeletal muscle. The between-subject variation in skeletal muscle gene expression was greater than that observed in response to prolonged ESA treatment. CONCLUSIONS Erythropoietin is unlikely to exert direct effects in human skeletal muscle due to a lack of Epo-R protein. Furthermore, prolonged ESA treatment does not seem to exert either direct or indirect effects on skeletal muscle gene expression.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark; Section of Sports Sciences, Institute of Public Health, Aarhus University, Aarhus, Denmark
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Christensen B, Ludvigsen M, Nellemann B, Kopchick JJ, Honoré B, Jørgensen JOL. Serum proteomic changes after randomized prolonged erythropoietin treatment and/or endurance training: detection of novel biomarkers. PLoS One 2015; 10:e0117119. [PMID: 25679398 PMCID: PMC4332672 DOI: 10.1371/journal.pone.0117119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 12/12/2014] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION Despite implementation of the biological passport to detect erythropoietin abuse, a need for additional biomarkers remains. We used a proteomic approach to identify novel serum biomarkers of prolonged erythropoiesis-stimulating agent (ESA) exposure (Darbepoietin-α) and/or aerobic training. TRIAL DESIGN Thirty-six healthy young males were randomly assigned to the following groups: Sedentary-placebo (n = 9), Sedentary-ESA (n = 9), Training-placebo (n = 10), or Training-ESA (n = 8). They were treated with placebo/Darbepoietin-α subcutaneously once/week for 10 weeks followed by a 3-week washout period. Training consisted of supervised biking 3/week for 13 weeks at the highest possible intensity. Serum was collected at baseline, week 3 (high dose Darbepoietin-α), week 10 (reduced dose Darbepoietin-α), and after a 3-week washout period. METHODS Serum proteins were separated according to charge and molecular mass (2D-gel electrophoresis). The identity of proteins from spots exhibiting altered intensity was determined by mass spectrometry. RESULTS Six protein spots changed in response to Darbepoietin-α treatment. Comparing all 4 experimental groups, two protein spots (serotransferrin and haptoglobin/haptoglobin related protein) showed a significant response to Darbepoietin-α treatment. The haptoglobin/haptoglobin related protein spot showed a significantly lower intensity in all subjects in the training-ESA group during the treatment period and increased during the washout period. CONCLUSION An isoform of haptoglobin/haptoglobin related protein could be a new anti-doping marker and merits further research. TRIAL REGISTRATION ClinicalTrials.gov NCT01320449.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark; Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Maja Ludvigsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark
| | - John J Kopchick
- Edison Biotechnology Institute Ohio University, Athens, Ohio, United States of America; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
| | - Bent Honoré
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jens Otto L Jørgensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Johansen RF, Søndergaard E, Sørensen LP, Nellemann B, Christiansen JS, Nielsen S. Isolated hyperglycaemia does not increase VLDL-triacylglycerol secretion in type 1 diabetic men. Diabetologia 2015; 58:355-62. [PMID: 25385409 DOI: 10.1007/s00125-014-3422-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 09/26/2014] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS In type 1 diabetes, abnormalities of both glucose and lipoprotein metabolism are seen. The relationship between these factors is not understood, but studies indicate that hyperglycaemia may increase hepatic VLDL-triacylglycerol (VLDL-TG) secretion and reduce VLDL-TG fatty acid oxidation, which could lead to the development of dyslipidaemia. The aim of this study was to determine the isolated effect of hyperglycaemia on VLDL-TG and NEFA kinetics in men with type 1 diabetes. METHODS VLDL-TG and palmitate kinetics were measured in eight men with type 1 diabetes using ex vivo labelled VLDL-TG and palmitate tracers. A 2.5 h basal period (plasma glucose 5 mmol/l) was followed by a 4 h hyperglycaemic period (plasma glucose 16 mmol/l). Steady-state VLDL-TG kinetics (VLDL-TG secretion, clearance and oxidation rates) were assessed by an isotope dilution technique using an intravenous primed-constant infusion of ex vivo labelled [1-(14)C]VLDL-TG in combination with sampling of blood and expired air. Palmitate turnover was measured using [9,10-(3)H]palmitate. RESULTS The VLDL-TG secretion rate (36.0 ± 9.6 vs 30.8 ± 6.1 μmol/min, NS) and clearance rate (209 ± 30.4 vs 197 ± 41.7 ml/min, NS) were unchanged during the basal and hyperglycaemic periods, resulting in unchanged VLDL-TG concentrations (0.25 ± 0.11 μmol/l vs 0.28 ± 0.10 μmol/l, NS). In addition, VLDL-TG fatty acid oxidation and palmitate flux were not changed during hyperglycaemia. CONCLUSIONS/INTERPRETATION Four hours of acute hyperglycaemia (16 mmol/l) without a concomitant increase in insulin does not alter VLDL-TG and NEFA kinetics in men with type 1 diabetes. CLINICAL TRIAL REGISTRY NUMBER NCT01178957.
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Affiliation(s)
- Rakel F Johansen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark,
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Nellemann B, Christensen B, Vissing K, Thams L, Sieljacks P, Larsen MS, Jørgensen JOL, Nielsen S. Ten weeks of aerobic training does not result in persistent changes in VLDL triglyceride turnover or oxidation in healthy men. Eur J Endocrinol 2014; 171:603-13. [PMID: 25117466 DOI: 10.1530/eje-14-0333] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Very low density lipoprotein triglyceride (VLDL-TG) and free fatty acids (FFA) constitute a substantial proportion of human energy supply both at rest and during exercise. Exercise acutely decreases VLDL-TG concentration, and VLDL-TG clearance is increased after an exercise bout. However, the effects of long-term training are not clear. DESIGN The aim was to investigate long-term effects of training by direct assessments of VLDL-TG and palmitate kinetics and oxidation in healthy lean men (n=9) at rest, before and after a 10-week training program, compared with a non-training control group (n=9). METHODS VLDL-TG kinetics were assessed by a primed constant infusion of [1-14C]VLDL-TG, and VLDL-TG oxidation by specific activity (14CO2) in expired air. The metabolic study days were placed 60-72 h after the last exercise bout. RESULTS Palmitate kinetics and oxidation were assessed by a 2 h constant infusion of [9,10-(3)H]palmitate. In the training group (n=9), maximal oxygen uptake increased significantly by ≈20% (P<0.05), and the insulin sensitivity (assessed by the hyperinsulinemic-euglycemic clamp) improved significantly (P<0.05). Despite these metabolic improvements, no changes were observed in VLDL-TG secretion, clearance, or oxidation or in palmitate kinetics. CONCLUSION We conclude that 10 weeks of exercise training did not induce changes in VLDL-TG and palmitate kinetics in healthy lean men.
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Affiliation(s)
- Birgitte Nellemann
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Kristian Vissing
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Line Thams
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Sieljacks
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Mads Sørensen Larsen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Jens Otto Lunde Jørgensen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
| | - Søren Nielsen
- Department of Endocrinology and Internal MedicineAarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, DenmarkSection of Sports ScienceDepartment of Public Health, Aarhus University, Aarhus, Denmark
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Larsen MS, Vissing K, Thams L, Sieljacks P, Dalgas U, Nellemann B, Christensen B. Erythropoietin administration alone or in combination with endurance training affects neither skeletal muscle morphology nor angiogenesis in healthy young men. Exp Physiol 2014; 99:1409-20. [PMID: 25128327 DOI: 10.1113/expphysiol.2014.080606] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim was to investigate the ability of an erythropoiesis-stimulating agent (ESA), alone or in combination with endurance training, to induce changes in human skeletal muscle fibre and vascular morphology. In a comparative study, 36 healthy untrained men were randomly dispersed into the following four groups: sedentary-placebo (SP, n = 9); sedentary-ESA (SE, n = 9); training-placebo (TP, n = 10); or training-ESA (TE, n = 8). The ESA or placebo was injected once weekly. Training consisted of progressive bicycling three times per week for 10 weeks. Before and after the intervention period, muscle biopsies and magnetic resonance images were collected from the thigh muscles, blood was collected, body composition measured and endurance exercise performance evaluated. The ESA treatment (SE and TE) led to elevated haematocrit, and both ESA treatment and training (SE, TP and TE) increased maximal O2 uptake. With regard to skeletal muscle morphology, TP alone exhibited increases in whole-muscle cross-sectional area and fibre diameter of all fibre types. Also exclusively for TP was an increase in type IIa fibres and a corresponding decrease in type IIx fibres. Furthermore, an overall training effect (TP and TE) was statistically demonstrated in whole-muscle cross-sectional area, muscle fibre diameter and type IIa and type IIx fibre distribution. With regard to muscle vascular morphology, TP and TE both promoted a rise in capillary to muscle fibre ratio, with no differences between the two groups. There were no effects of ESA treatment on any of the muscle morphological parameters. Despite the haematopoietic effects of ESA, we provide novel evidence that endurance training rather than ESA treatment induces adaptational changes in angiogenesis and muscle morphology.
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Affiliation(s)
- Mads S Larsen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Kristian Vissing
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Line Thams
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Sieljacks
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Ulrik Dalgas
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Nellemann B, Søndergaard E, Jensen J, Pedersen SB, Jessen N, Jørgensen JOL, Nielsen S. Kinetics and utilization of lipid sources during acute exercise and acipimox. Am J Physiol Endocrinol Metab 2014; 307:E199-208. [PMID: 24895285 DOI: 10.1152/ajpendo.00043.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Overweight is associated with abnormalities of lipid metabolism, many of which are reversed by exercise. We investigated the impact of experimental antilipolysis and acute exercise on lipid kinetics and oxidation from VLDL-TG, plasma FFA, and "residual lipids" in overweight men (n = 8) using VLDL-TG and palmitate tracers in combination with muscle biopsies in a randomized, placebo-controlled design. Participants received placebo or acipimox on each study day (4 h of rest, 90 min of exercise at 50% V(O(2 max))). Exercise suppressed VLDL-TG secretion significantly during placebo but not acipimox (placebo-rest: 64.2 ± 9.4; placebo-exercise: 48.3 ± 8.0; acipimox-rest: 55.2 ± 13.4; acipimox-exercise: 52.0 ± 10.9). Resting oxidation of VLDL-TG FA and FFA was significantly reduced during acipimox compared with placebo, whereas "residual lipid oxidation" increased significantly [VLDL-TG oxidation (placebo: 18 ± 3 kcal/h; acipimox: 11 ± 2 kcal/h), FFA oxidation (placebo: 14 ± 2 kcal/h; acipimox: 4 ± 0.5 kcal/h), and residual lipid oxidation (placebo: 3 ± 5 kcal/h; acipimox: 14 ± 5 kcal/h)]. Additionally, during exercise on both placebo and acipimox, oxidation of VLDL-TG and FFA increased, but the relative contribution to total lipid oxidation diminished, except for FFA, which remained unchanged during acipimox. Residual lipid oxidation increased significantly during exercise in both absolute and relative terms. Changes in selected cellular enzymes and proteins provided no explanations for kinetic changes. In conclusion, suppressed FFA availability blunts the effect of exercise on VLDL-TG secretion and modifies the contribution of lipid sources for oxidation.
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Affiliation(s)
- Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway; and
| | - Esben Søndergaard
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway; and
| | - Steen Bønløkke Pedersen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Jessen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark;
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21
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Vendelbo MH, Møller AB, Christensen B, Nellemann B, Clasen BFF, Nair KS, Jørgensen JOL, Jessen N, Møller N. Fasting increases human skeletal muscle net phenylalanine release and this is associated with decreased mTOR signaling. PLoS One 2014; 9:e102031. [PMID: 25020061 PMCID: PMC4096723 DOI: 10.1371/journal.pone.0102031] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 06/13/2014] [Indexed: 12/12/2022] Open
Abstract
Aim Fasting is characterised by profound changes in energy metabolism including progressive loss of body proteins. The underlying mechanisms are however unknown and we therefore determined the effects of a 72-hour-fast on human skeletal muscle protein metabolism and activation of mammalian target of rapamycin (mTOR), a key regulator of cell growth. Methods Eight healthy male volunteers were studied twice: in the postabsorptive state and following 72 hours of fasting. Regional muscle amino acid kinetics was measured in the forearm using amino acid tracers. Signaling to protein synthesis and breakdown were assessed in skeletal muscle biopsies obtained during non-insulin and insulin stimulated conditions on both examination days. Results Fasting significantly increased forearm net phenylalanine release and tended to decrease phenylalanine rate of disappearance. mTOR phosphorylation was decreased by ∼50% following fasting, together with reduced downstream phosphorylation of 4EBP1, ULK1 and rpS6. In addition, the insulin stimulated increase in mTOR and rpS6 phosphorylation was significantly reduced after fasting indicating insulin resistance in this part of the signaling pathway. Autophagy initiation is in part regulated by mTOR through ULK1 and fasting increased expression of the autophagic marker LC3B-II by ∼30%. p62 is degraded during autophagy but was increased by ∼10% during fasting making interpretation of autophagic flux problematic. MAFbx and MURF1 ubiquitin ligases remained unaltered after fasting indicating no change in protesomal protein degradation. Conclusions Our results show that during fasting increased net phenylalanine release in skeletal muscle is associated to reduced mTOR activation and concomitant decreased downstream signaling to cell growth.
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Affiliation(s)
- Mikkel Holm Vendelbo
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- * E-mail:
| | - Andreas Buch Møller
- Research Laboratory for Biochemical Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Berthil Frederik Forrest Clasen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Research Laboratory for Biochemical Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - K. Sreekumaran Nair
- Division of Endocrinology, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota, United States of America
| | | | - Niels Jessen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Research Laboratory for Biochemical Pathology, Aarhus University Hospital, Aarhus, Denmark
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Møller
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Nellemann B, Vendelbo MH, Nielsen TS, Bak AM, Høgild M, Pedersen SB, Biensø RS, Pilegaard H, Møller N, Jessen N, Jørgensen JOL. Growth hormone-induced insulin resistance in human subjects involves reduced pyruvate dehydrogenase activity. Acta Physiol (Oxf) 2014; 210:392-402. [PMID: 24148194 DOI: 10.1111/apha.12183] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/09/2013] [Accepted: 10/17/2013] [Indexed: 12/15/2022]
Abstract
AIM Insulin resistance induced by growth hormone (GH) is linked to promotion of lipolysis by unknown mechanisms. We hypothesized that suppression of the activity of pyruvate dehydrogenase in the active form (PDHa) underlies GH-induced insulin resistance similar to what is observed during fasting. METHODS Eight healthy male subjects were studied four times in a randomized, single-blinded parallel design: Control, GH, Fasting (36 h) and GH + Fasting. GH (30 ng × kg(-1) × min(-1)) or saline was infused throughout the metabolic study day. Substrate metabolism and insulin sensitivity were assessed by indirect calorimetry and isotopically determined rates of glucose turnover before and after a hyperinsulinemic euglycemic clamp. PDHa activity, PDH-E1α phosphorylation, PDK4 expression and activation of insulin signalling proteins were assessed in skeletal muscle. RESULTS Both fasting and GH promoted lipolysis, which was associated with ≈50% reduction in insulin sensitivity compared with the control day. PDHa activity was significantly reduced by GH as well as fasting. This was associated with increased inhibitory PDH-E1α phosphorylation on site 1 (Ser(293)) and 2 (Ser(300)) and up-regulation of PDK4 mRNA, while canonical insulin signalling to glucose transport was unaffected. CONCLUSION Competition between intermediates of glucose and fatty acids seems to play a causal role in insulin resistance induced by GH in human subjects.
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Affiliation(s)
- B. Nellemann
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - M. H. Vendelbo
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - T. S. Nielsen
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - A. M. Bak
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - M. Høgild
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - S. B. Pedersen
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - R. S. Biensø
- Centre of Inflammation and Metabolism & August Krogh Centre; Department of Biology; University of Copenhagen; Copenhagen Denmark
| | - H. Pilegaard
- Centre of Inflammation and Metabolism & August Krogh Centre; Department of Biology; University of Copenhagen; Copenhagen Denmark
| | - N. Møller
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - N. Jessen
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
| | - J. O. L. Jørgensen
- Department of Endocrinology and Internal Medicine; Aarhus University Hospital; Aarhus Denmark
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Christensen B, Nellemann B, Larsen MS, Thams L, Sieljacks P, Vestergaard PF, Bibby BM, Vissing K, Stødkilde-Jørgensen H, Pedersen SB, Møller N, Nielsen S, Jessen N, Jørgensen JOL. Whole body metabolic effects of prolonged endurance training in combination with erythropoietin treatment in humans: a randomized placebo controlled trial. Am J Physiol Endocrinol Metab 2013; 305:E879-89. [PMID: 23921143 DOI: 10.1152/ajpendo.00269.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
UNLABELLED Erythropoietin (Epo) administration improves aerobic exercise capacity and insulin sensitivity in renal patients and also increases resting energy expenditure (REE). Similar effects are observed in response to endurance training. The aim was to compare the effects of endurance training with erythropoiesis-stimulating agent (ESA) treatment in healthy humans. Thirty-six healthy untrained men were randomized to 10 wk of either: 1) placebo (n = 9), 2) ESA (n = 9), 3) endurance training (n = 10), or 4) ESA and endurance training (n = 8). In a single-blinded design, ESA/placebo was injected one time weekly. Training consisted of biking for 1 h at 65% of wattmax three times per week. Measurements performed before and after the intervention were as follows: body composition, maximal oxygen uptake, insulin sensitivity, REE, and palmitate turnover. Uncoupling protein 2 (UCP2) mRNA levels were assessed in skeletal muscle. Fat mass decreased after training (P = 0.003), whereas ESA induced a small but significant increase in intrahepatic fat (P = 0.025). Serum free fatty acid (FFA) levels and palmitate turnover decreased significantly in response to training, whereas the opposite pattern was found after ESA. REE corrected for lean body mass increased in response to ESA and training, and muscle UCP2 mRNA levels increased after ESA (P = 0.035). Insulin sensitivity increased only after training (P = 0.011). IN CONCLUSION 1) insulin sensitivity is not improved after ESA treatment despite improved exercise capacity, 2) the calorigenic effects of ESA may be related to increased UCP2 gene expression in skeletal muscle, and 3) training and ESA exert opposite effects on lipolysis under basal conditions, increased FFA levels and liver fat fraction was observed after ESA treatment.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
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Abstract
Direct FFA storage in adipose tissue is a recently appreciated pathway for postabsorptive lipid storage. We evaluated the effect of body fat distribution on direct FFA storage in women with different obesity phenotypes. Twenty-eight women [10 upper body overweight/obese (UBO; WHR >0.85, BMI >28 kg/m(2)), 11 lower body overweight/obese (LBO; WHR <0.80, BMI >28 kg/m(2)), and 7 lean (BMI <25 kg/m(2))] received an intravenous bolus dose of [9,10-(3)H]palmitate- and [1-(14)C]triolein-labeled VLDL tracer followed by upper body subcutaneous (UBSQ) and lower body subcutaneous (LBSQ) fat biopsies. Regional fat mass was assessed by combining DEXA and CT scanning. We report greater fractional storage of FFA in UBSQ fat in UBO women compared with lean women (P < 0.01). The LBO women had greater storage per 10(6) fat cells in LBSQ adipocytes compared with UBSQ adipocytes (P = 0.04), whereas the other groups had comparable storage in UBSQ and LBSQ adipocytes. Fractional FFA storage was significantly associated with fractional VLDL-TG storage in both UBSQ (P < 0.01) and LBSQ (P = 0.03) adipose tissue. In conclusion, UBO women store a greater proportion of FFA in the UBSQ depot compared with lean women. In addition, LBO women store FFA more efficiently in LBSQ fat cells compared with UBSQ fat cells, which may play a role in development of their LBO phenotype. Finally, direct FFA storage and VLDL-TG fatty acid storage are correlated, indicating they may share a common rate-limiting pathway for fatty acid storage in adipose tissue.
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Affiliation(s)
- E Søndergaard
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark
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Nellemann B, Gormsen LC, Sørensen LP, Christiansen JS, Nielsen S. Impaired insulin-mediated antilipolysis and lactate release in adipose tissue of upper-body obese women. Obesity (Silver Spring) 2012; 20:57-64. [PMID: 21959346 DOI: 10.1038/oby.2011.290] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Upper-body/visceral obesity is associated with abnormalities of free fatty acid (FFA) metabolism and greater risk of developing type 2 diabetes compared with lower-body obesity. In lean subjects lipolysis is readily suppressed by insulin; however, metabolic inflexibility with respect to antilipolysis is a frequent finding in obesity, partly determined by body composition. This study investigates effects of insulin on regional adipose tissue lipolysis and lactate levels in upper-body overweight/obese (UBO), lower-body overweight/obese (LBO), and lean women. The microdialysis technique was used to assess adipose tissue glycerol and lactate concentrations in abdominal and femoral fat during a 5-h basal period and a 2-h hyperinsulinemic euglycemic clamp. The main findings were that the antilipolytic effect of insulin was attenuated in abdominal fat of UBO (glycerol reduction, abd (%): UBO 40.4 (-14 to 66), LBO 46.0 (-8 to 66), lean 66.2 (2-78), ANOVA, P < 0.05), and in femoral fat in both obese groups (glycerol reduction, fem (%): UBO 44.4 (35-67), LBO 44.4 (0-63), lean 65.0 (43-79), ANOVA, P < 0.05). Further, abdominal fat insulin-mediated increase in lactate concentration was greater in lean women compared with UBO women (lactate increase, abd (%): UBO -6.1 (-37.1 to 57.4), LBO 16.5 (-32.2 to 112.5), lean 51.4 (-45.7 to 162.9), P < 0.05), whereas no differences were found between groups in femoral fat (lactate increase, fem (%), UBO -12.9 (-43 to 24), LBO 12.7 (-30.7 to 92), lean 27.6 (-9.5 to 123.8), not significant). Respiratory exchange ratio (RER) increased significantly and similarly in all groups. So, UBO women were metabolically inflexible with respect to insulins antilipolytic and lactate increasing effects in abdominal adipose tissue. These phenomena are probably both consequences of insulin resistance of adipose tissue.
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Affiliation(s)
- Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Søndergaard E, Nellemann B, Sørensen LP, Gormsen LC, Christiansen JS, Ernst E, Dueholm M, Nielsen S. Similar VLDL-TG storage in visceral and subcutaneous fat in obese and lean women. Diabetes 2011; 60:2787-91. [PMID: 21911742 PMCID: PMC3198059 DOI: 10.2337/db11-0604] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Excess visceral fat accumulation is associated with the metabolic disturbances of obesity. Differential lipid redistribution through lipoproteins may affect body fat distribution. This is the first study to investigate VLDL-triglyceride (VLDL-TG) storage in visceral fat. RESEARCH DESIGN AND METHODS Nine upper-body obese (UBO; waist circumference >88 cm) and six lean (waist circumference <80 cm) women scheduled for elective tubal ligation surgery were studied. VLDL-TG storage in visceral, upper-body subcutaneous (UBSQ), and lower-body subcutaneous (LBSQ) fat were measured with [9,10-(3)H]-triolein-labeled VLDL. RESULTS VLDL-TG storage in visceral fat accounted for only ~0.8% of VLDL-TG turnover in UBO and lean women, respectively. A significantly larger proportion of VLDL-TG turnover was stored in UBSQ (~5%) and LBSQ (~4%) fat. The VLDL-TG fractional storage was similar in UBO and lean women for all regional depots. VLDL-TG fractional storage and VLDL-TG concentration were correlated in UBO women in UBSQ fat (r = 0.68, P = 0.04), whereas an inverse association was observed for lean women in visceral (r = -0.89, P = 0.02) and LBSQ (r = -0.87, P = 0.02) fat. CONCLUSIONS VLDL-TG storage efficiency is similar in all regional fat depots, and trafficking of VLDL-TG into different adipose tissue depots is similar in UBO and lean women. Postabsorptive VLDL-TG storage is unlikely to be of major importance in the development of preferential upper-body fat distribution in obese women.
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Affiliation(s)
- Esben Søndergaard
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Lars P. Sørensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Lars C. Gormsen
- Department of Clinical Physiology and Nuclear Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Jens S. Christiansen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Erik Ernst
- Department of Gynecology and Obstetrics, Aarhus University Hospital, Aarhus, Denmark
| | - Margit Dueholm
- Department of Gynecology and Obstetrics, Aarhus University Hospital, Aarhus, Denmark
| | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Corresponding author: Søren Nielsen,
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Nellemann B, Gregersen HE, Olesen JL. [Picture of the month: stress fracture]. Ugeskr Laeger 2011; 173:2275. [PMID: 21917231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Sørensen LP, Søndergaard E, Nellemann B, Christiansen JS, Gormsen LC, Nielsen S. Increased VLDL-triglyceride secretion precedes impaired control of endogenous glucose production in obese, normoglycemic men. Diabetes 2011; 60:2257-64. [PMID: 21810597 PMCID: PMC3161323 DOI: 10.2337/db11-0040] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To assess basal and insulin-mediated VLDL-triglyceride (TG) kinetics and the relationship between VLDL-TG secretion and hepatic insulin resistance assessed by endogenous glucose production (EGP) in obese and lean men. RESEARCH DESIGN AND METHODS A total of 12 normoglycemic, obese (waist-to-hip ratio >0.9, BMI >30 kg/m(2)) and 12 lean (BMI 20-25 kg/m(2)) age-matched men were included. Ex vivo-labeled [1-(14)C]VLDL-TGs and [3-(3)H]glucose were infused postabsorptively and during a hyperinsulinemic-euglycemic clamp to determine VLDL-TG kinetics and EGP. Body composition was determined by dual X-ray absorptiometry and computed tomography scanning. Energy expenditure and substrate oxidation rates were measured by indirect calorimetry. RESULTS Basal VLDL-TG secretion rates were increased in obese compared with lean men (1.25 ± 0.34 vs. 0.86 ± 0.34 μmol/kg fat-free mass [FFM]/min; P = 0.011), whereas there was no difference in clearance rates (150 ± 56 vs. 162 ± 77 mL/min; P = NS), resulting in greater VLDL-TG concentrations (0.74 ± 0.40 vs. 0.38 ± 0.20 mmol/L; P = 0.011). The absolute insulin-mediated suppression of VLDL-TG secretion was similar in the groups. However, the percentage reduction (-36 ± 18 vs. -54 ± 10%; P = 0.008) and achieved VLDL-TG secretion rates (0.76 ± 0.20 vs. 0.41 ± 0.19 μmol/kg FFM/min; P < 0.001) were impaired in obese men. Furthermore, clearance rates decreased significantly in obese men, but there was no significant change in lean men (-17 ± 18 vs. 7 ± 20%; P = 0.007), resulting in less percentage reduction of VLDL-TG concentrations in obese men (-22 ± 20 vs. -56 ± 11%; P < 0.001). Insulin-suppressed EGP was similar (0.4 [0.0-0.8] vs. 0.1 [0.0-1.2] mg/kg FFM/min (median [range]); P = NS), and the percentage reduction was equivalent (-80% [57-98] vs. -98% [49-100], P = NS). Insulin-mediated glucose disposal was significantly reduced in obese men. CONCLUSIONS Basal VLDL-TG secretion rates are increased in normoglycemic but insulin-resistant, obese men, resulting in hypertriglyceridemia. Insulin-mediated suppression of EGP is preserved in obese men, whereas suppression of VLDL-TG secretion is less pronounced in obese men. Compared with EGP, the inability to achieve suppression of VLDL-TG secretions to a level similar to control subjects during hyperinsulinemia seems to be an early manifestation in male obesity.
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Affiliation(s)
- Lars P. Sørensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Søndergaard
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Jens S. Christiansen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Lars C. Gormsen
- Department of Nuclear Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Søren Nielsen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Corresponding author: Søren Nielsen,
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Abstract
Adipose tissue lipoprotein lipase (LPL) is a necessary enzyme for storage of very-low-density lipoprotein-triglyceride (VLDL-TG), but whether it is a rate-determining step is unknown. To test this hypothesis we included 10 upper-body obese (UBO), 11 lower-body obese (LBO), and 8 lean women. We infused ex vivo-labeled VLDL-(14)C-TG and then performed adipose tissue biopsies to understand the relationship between VLDL-TG storage and LPL activity in femoral and upper-body subcutaneous fat. Both fractional tracer storage and rate of storage of the VLDL-TG tracer were evaluated. VLDL-TG storage was also examined as a function of regional adipose tissue blood flow (ATBF), insulin, VLDL-TG turnover, regional fat mass, fat-free mass (FFM), and fat cell size. LPL activity per adipocyte was significantly greater in obese than lean women but not significantly different per gram lipid. Both VLDL-TG fractional tracer storage per kg lipid and VLDL-TG storage rate per kg lipid were similar in abdominal and femoral fat in all three groups and were not significantly different between groups. Multiple regression analysis identified FFM and femoral fat mass as significant independent predictors of VLDL-TG fractional tracer storage and insulin as a significant predictor of VLDL-TG fatty acid storage rate. LPL activity, ATBF, and VLDL-TG turnover did not predict VLDL-TG storage. We conclude that lower FFM and greater plasma insulin are associated with greater VLDL-TG deposition in abdominal subcutaneous and femoral fat. Greater femoral fat mass signals greater femoral VLDL-TG storage. We suggest that the differences in VLDL-TG storage in abdominal and femoral fat that occur with progressive obesity are regulated through mechanisms other than LPL activity.
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30
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Sondergaard E, Gormsen LC, Nellemann B, Vestergaard ET, Christiansen JS, Nielsen S. Visceral fat mass is a strong predictor of circulating ghrelin levels in premenopausal women. Eur J Endocrinol 2009; 160:375-9. [PMID: 19106245 DOI: 10.1530/eje-08-0735] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE A well known inverse relationship exists between obesity and circulating ghrelin concentrations. However, obesity is a heterogeneous disease entity and upper-body obesity (UBO) is associated with more profound metabolic disturbances than lower-body obesity (LBO). We therefore aimed to investigate the impact of body composition on circulating ghrelin levels in women spanning a wide range of body composition phenotypes. SUBJECTS AND METHODS Ten (UBO; waist-to-hip ratio (WHR) >0.85, body mass index (BMI) >28 kg/m(2)), ten LBO (WHR <0.80, BMI >28 kg/m(2)) and ten lean women (BMI<25 kg/m(2)) were studied. Total ghrelin levels were measured under basal and hyperinsulinemic (0.6 mU/kg per min) conditions. Body fat distribution was determined by dual X-ray absorptiometry in combination with computed tomography at the L2-L3 level. RESULTS As expected, an inverse correlation existed between basal ghrelin concentration and BMI (r=-0.40, P=0.03) and total fat mass (r=-0.39, P=0.04). Visceral fat mass was a strong predictor (r=-0.56, P=0.003) of circulating ghrelin levels, even when adjusted for BMI (P=0.02) or body composition group (P=0.04). The suppressive effect of insulin on ghrelin concentration was significantly diminished in the UBO compared with the lean controls (P=0.012) and a highly significant inverse correlation existed with visceral fat mass (r=-0.52, P=0.004). CONCLUSIONS Visceral fat mass is a strong predictor of basal ghrelin concentrations and also attenuates the suppressive effect of insulin on ghrelin concentrations. These data provide further evidence that the UBO phenotype is associated with more profound metabolic abnormalities than obesity per se.
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Affiliation(s)
- E Sondergaard
- Medical Department M (Endocrinology & Diabetes), Aarhus University Hospital, Aarhus C, Denmark.
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Gormsen LC, Nellemann B, Sørensen LP, Jensen MD, Christiansen JS, Nielsen S. Impact of body composition on very-low-density lipoprotein-triglycerides kinetics. Am J Physiol Endocrinol Metab 2009; 296:E165-73. [PMID: 18984851 DOI: 10.1152/ajpendo.90675.2008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Upper body obese (UBO) subjects have greater cardiovascular disease risk than lower body obese (LBO) or lean subjects. Obesity is also associated with hypertriglyceridemia that may involve greater production and impaired removal of very-low-density lipoprotein (VLDL)-triglycerides (TG). In these studies, we assessed the impact of body composition on basal VLDL-TG production, VLDL-TG oxidation, and VLDL-TG storage. VLDL-TG kinetics were assessed in 10 UBO, 10 LBO, and 10 lean women using a bolus injection of [1-(14)C]VLDL-TG. VLDL-TG oxidation was measured by (14)CO(2) production (hyamine trapping) and VLDL-TG adipose tissue storage by fat biopsies. Insulin sensititvity was assessed by the hyperinsulinemic-euglycemic clamp technique and body composition by dual X-ray absorptiometry in combination with computed tomography. Hepatic VLDL-TG production was significantly greater in UBO than in lean women [(mumol/min) UBO: 64.8 (SD 40.0) vs. LBO: 42.5 (SD 25.6) vs. lean: 31.8 (SD 13.3), P = 0.04], whereas VLDL-TG oxidation was similar in the three groups and averaged 20% of resting energy expenditure [(mumol/min) UBO: 38.3 (SD 26.5) vs. LBO: 23.5 (SD 13.5) vs. lean: 21.1 (SD 9.7), P = 0.09]. In UBO women, more VLDL-TG was deposited in upper body subcutaneous fat [VLDL-TG redeposition in abdominal adipose tissue (mumol/min): UBO: 5.0 (SD 2.9) vs. LBO: 4.0 (SD 3.2) vs. lean: 1.3 (SD 1.0), ANOVA P = 0.01]; in LBO women, more VLDL-TG was deposited in femoral fat [VLDL-TG redeposition in femoral adipose tissue (mumol/min): UBO: 5.1 (SD 3.1) vs. LBO: 5.8 (SD 4.3) vs. lean: 2.3 (SD 1.5), ANOVA P = 0.04]. Only a small proportion of VLDL-TG (8-16%) was partitioned into redeposition in either group. We found that elevated VLDL-TG production without concomitant increased clearance via oxidation and adipose tissue redeposition contributes to hypertriglyceridemia in UBO women.
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Affiliation(s)
- Lars C Gormsen
- Dept. of Nuclear Medicine, Aarhus Univ. Hospital, DK-8000 Aarhus C, Denmark.
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Nellemann B, Gormsen LC, Dollerup J, Schmitz O, Mogensen CE, Rasmussen LM, Nielsen S. Simvastatin reduces plasma osteoprotegerin in type 2 diabetic patients with microalbuminuria. Diabetes Care 2007; 30:3122-4. [PMID: 17804683 DOI: 10.2337/dc07-0919] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Badre-Esfahani S, Nellemann B, Danielsen D, Fisker S, Christiansen JS, Jørgensen JOL. Assessment of hydration by means of bioelectrical impedance and arm muscle area during growth hormone (GH) replacement therapy: A prospective study of 130 GH-deficient patients. Growth Horm IGF Res 2007; 17:227-233. [PMID: 17347010 DOI: 10.1016/j.ghir.2007.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 01/20/2007] [Accepted: 01/24/2007] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Growth hormone (GH)-deficiency is associated with a reduced extracellular volume (ECV), whereas GH replacement may cause fluid retention. We have tested a simple method to assess hydration in GH-deficient patients (GHD) based on concomitant measurements of body resistance by bioelectrical impedance analysis (BIA), and arm muscle area (AMA). DESIGN We prospectively followed 130 patients (54 females, 76 males) with adult-onset GHD before and during 1-5 years GH replacement therapy. METHODS Concomitant measurements of body resistance and AMA were done on four occasions: before treatment, after one month and one year of treatment, and at the most recent visit. Based on normative data obtained in 142 women and 84 men an inverse relationship was documented between body resistance and AMA. Assuming that linear height and the concentration of electrolytes remain constant, body resistance at a given AMA will reflect specific hydration. RESULTS In the patients a gender-specific inverse correlation between body resistance and AMA existed, which was different from the control group and changed during GH replacement. A deviation between predicted (based on normative data) and measured body resistance at a given AMA was recorded in the patients before and during therapy compatible with relative dehydration in the untreated state followed by an increase in hydration during therapy. CONCLUSIONS Concomitant measurements of BIA and AMA in GHD patients may provide a non-invasive and simple means to estimate hydration before and during GH replacement.
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Affiliation(s)
- Sara Badre-Esfahani
- Medical Department M (Endocrinology and Diabetes), Aarhus University Hospital, Nørrebrograde 44, DK-8000 C Aarhus, Denmark
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