1
|
Modvig IM, Smits MM, Galsgaard KD, Hjørne AP, Drzazga AK, Rosenkilde MM, Holst JJ. L-valine is a powerful stimulator of GLP-1 secretion in rodents and stimulates secretion through ATP-sensitive potassium channels and voltage-gated calcium channels. Nutr Diabetes 2024; 14:43. [PMID: 38862477 PMCID: PMC11166632 DOI: 10.1038/s41387-024-00303-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/30/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
BACKGROUND We previously reported that, among all the naturally occurring amino acids, L-valine is the most powerful luminal stimulator of glucagon-like peptide 1 (GLP-1) release from the upper part of the rat small intestine. This makes L-valine an interesting target for nutritional-based modulation of GLP-1 secretion. However, the molecular mechanism of L-valine-induced secretion remains unknown. METHODS We aimed to investigate the effect of orally given L-valine in mice and to identify the molecular details of L-valine stimulated GLP-1 release using the isolated perfused rat small intestine and GLUTag cells. In addition, the effect of L-valine on hormone secretion from the distal intestine was investigated using a perfused rat colon. RESULTS Orally given L-valine (1 g/kg) increased plasma levels of active GLP-1 comparably to orally given glucose (2 g/kg) in male mice, supporting that L-valine is a powerful stimulator of GLP-1 release in vivo (P > 0.05). Luminal L-valine (50 mM) strongly stimulated GLP-1 release from the perfused rat small intestine (P < 0.0001), and inhibition of voltage-gated Ca2+-channels with nifedipine (10 μM) inhibited the GLP-1 response (P < 0.01). Depletion of luminal Na+ did not affect L-valine-induced GLP-1 secretion (P > 0.05), suggesting that co-transport of L-valine and Na+ is not important for the depolarization necessary to activate the voltage-gated Ca2+-channels. Administration of the KATP-channel opener diazoxide (250 μM) completely blocked the L-valine induced GLP-1 response (P < 0.05), suggesting that L-valine induced depolarization arises from metabolism and opening of KATP-channels. Similar to the perfused rat small intestine, L-valine tended to stimulate peptide tyrosine-tyrosine (PYY) and GLP-1 release from the perfused rat colon. CONCLUSIONS L-valine is a powerful stimulator of GLP-1 release in rodents. We propose that intracellular metabolism of L-valine leading to closure of KATP-channels and opening of voltage-gated Ca2+-channels are involved in L-valine induced GLP-1 secretion.
Collapse
Affiliation(s)
- Ida Marie Modvig
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mark M Smits
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Douglas Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anna Pii Hjørne
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anna Katarzyna Drzazga
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Łódź, Poland
| | - Mette Marie Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Juul Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
2
|
Wang F, Dou P, Wei W, Liu PJ. Effects of high-protein diets on the cardiometabolic factors and reproductive hormones of women with polycystic ovary syndrome: a systematic review and meta-analysis. Nutr Diabetes 2024; 14:6. [PMID: 38424054 PMCID: PMC10904368 DOI: 10.1038/s41387-024-00263-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024] Open
Abstract
The optimal dietary regimen for polycystic ovary syndrome (PCOS) has not been identified. High-protein diets (HPDs) are effective for weight control in individuals with metabolic abnormalities, but no systematic meta-analyses have yet summarised the effects of HPDs on PCOS. Seven electronic databases were searched from inception to 30 April 2023, and studies comparing the effects of HPDs and other diets on the anthropometrics, metabolic factors, and hormonal profiles for PCOS were identified. Data were pooled using random-effects models and expressed as weighted mean differences and 95% confidence intervals. The risk of bias was assessed by Cochrane Collaboration tool. Eight trials involving 300 women with PCOS were included. Compared with isocaloric balanced diets (BDs), HPDs significantly reduced fasting insulin (-2.69 μIU/mL, 95% CI [-3.81, -1.57], P < 0.0001, I2 = 46%) and homoeostatic model assessment for insulin resistance (HOMA-IR-0.41, 95% CI [-0.80, -0.02], P = 0.04, I2 = 94%) in women with PCOS. However, HPDs and BDs had comparable effects on weight loss, abdominal adiposity, lipid profiles, and reproductive hormones (all P ≥ 0.05). HPDs may benefit women with PCOS in terms of improving insulin resistance, supporting for their use as one of the dietary management options for PCOS, however further RCTs in larger and broader settings are required to confirm these observations and investigate the mechanism behind it.
Collapse
Affiliation(s)
- Fang Wang
- Department of Clinical Nutrition, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Dongdansantiao, Dongcheng District, 100730, Beijing, China
| | - Pan Dou
- Department of Clinical Nutrition, Peking University First Hospital, No.7 Xishiku Dajie, Xicheng District, 100034, Beijing, China
| | - Wei Wei
- Department of Clinical Nutrition, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Dongdansantiao, Dongcheng District, 100730, Beijing, China
| | - Peng Ju Liu
- Department of Clinical Nutrition, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Dongdansantiao, Dongcheng District, 100730, Beijing, China.
| |
Collapse
|
3
|
Chiriacò M, Nesti L, Natali A, Santoro N, Caprio S, Tricò D. Proatherogenic changes in lipoprotein particles associated with a high triglyceride to high-density lipoprotein cholesterol ratio in youths. Obesity (Silver Spring) 2023; 31:1894-1902. [PMID: 37227148 PMCID: PMC10330115 DOI: 10.1002/oby.23767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/12/2023] [Accepted: 02/21/2023] [Indexed: 05/26/2023]
Abstract
OBJECTIVE A high triglyceride (TG) to high-density lipoprotein cholesterol (HDL) ratio (TG/HDL) predicts atherosclerosis and cardiovascular events. This study examined whether a proatherogenic distribution of plasma lipoprotein subclasses is associated with a high TG/HDL ratio in youths with obesity. METHODS Lipoprotein particle concentration and size were measured by proton nuclear magnetic resonance in a multiethnic cohort of 592 adolescents with overweight/obesity (age 13 ± 3 years, 58% females, BMI z score 2.1 ± 0.8) who were phenotyped with a 3-hour oral glucose tolerance test and abdominal magnetic resonance imaging. RESULTS The highest TG/HDL quartile showed a higher particle concentration of very low-density lipoprotein (VLDL; +178%, p < 0.0001), intermediate-density lipoprotein (+338%, p < 0.0001), and low-density lipoprotein (LDL; +42%, p < 0.0001), compared with the lowest quartile. The prevalence of large VLDL, very small LDL, and small HDL progressively increased across TG/HDL quartiles. The TG/HDL ratio correlated positively with the average particle size of VLDL (r = 0.37, p < 0.0001) and negatively with particle size of both LDL (r = -0.51, p < 0.0001) and HDL (r = -0.69, p < 0.0001). These associations were independent of sex, age, race/ethnicity, body mass, fasting plasma glucose, and insulin sensitivity. CONCLUSIONS In youths with obesity, an elevated TG/HDL ratio is associated with high concentrations of proatherogenic lipoprotein subclasses. This phenotype may explain the increased cardiovascular risk associated with a high TG/HDL ratio.
Collapse
Affiliation(s)
- Martina Chiriacò
- Metabolism, Nutrition, and Atherosclerosis Laboratory, University of Pisa, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Lorenzo Nesti
- Metabolism, Nutrition, and Atherosclerosis Laboratory, University of Pisa, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Natali
- Metabolism, Nutrition, and Atherosclerosis Laboratory, University of Pisa, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nicola Santoro
- Kansas University Medical Center, Kansas City, KS, USA
- Department of Medicine and Health Sciences, “V.Tiberio” University of Molise, Campobasso, Italy
| | - Sonia Caprio
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT
| | - Domenico Tricò
- Metabolism, Nutrition, and Atherosclerosis Laboratory, University of Pisa, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| |
Collapse
|
4
|
Tricò D. Nutrients and Cardiometabolic Health in Type 2 Diabetes. Nutrients 2023; 15:nu15112517. [PMID: 37299480 DOI: 10.3390/nu15112517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/16/2023] [Indexed: 06/12/2023] Open
Abstract
Paralleling the obesity pandemic, the prevalence and socioeconomic burden of type 2 diabetes are growing worldwide, requiring immediate attention and novel cost-effective preventive and therapeutic strategies [...].
Collapse
Affiliation(s)
- Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Via Roma 67, 56126 Pisa, Italy
| |
Collapse
|
5
|
Yong YN, Dong J, Pakkiri LS, Henry CJ, Haldar S, Drum CL. Chronometabolism: The Timing of the Consumption of Meals Has a Greater Influence Than Glycemic Index (GI) on the Postprandial Metabolome. Metabolites 2023; 13:metabo13040490. [PMID: 37110149 PMCID: PMC10143625 DOI: 10.3390/metabo13040490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 03/30/2023] Open
Abstract
Eating late in the day is associated with circadian desynchrony, resulting in dysregulated metabolism and increased cardiometabolic disease risk. However, the underlying mechanisms remain unclear. Using targeted metabolomics of postprandial plasma samples from a secondary analysis of a randomised 2 × 2 crossover study in 36 healthy older Chinese adults, we have compared postprandial metabolic responses between high (HI) glycemic index (GI) or low-GI (LO) meals, consumed either at breakfast (BR) or at dinner (DI). 29 out of 234 plasma metabolites exhibited significant differences (p < 0.05) in postprandial AUC between BR and DI sessions, whereas only five metabolites were significantly different between HI and LO sessions. There were no significant interactions between intake timing and meal GI. Lower glutamine: glutamate ratio, lower lysine and higher trimethyllysine (TML) levels were found during DI compared with BR, along with greater postprandial reductions (δAUC) in creatine and ornithine levels during DI, indicating a worse metabolic state during the evening DI period. Greater reductions (δAUC) in postprandial creatine and ornithine were also observed during HI compared with LO (both p < 0.05). These metabolomic changes may indicate potential molecular signatures and/or pathways linking metabolic responses with cardiometabolic disease risk between different meal intake timings and/or meals with variable GI.
Collapse
|
6
|
Song LL, Wang N, Zhang JP, Yu LP, Chen XP, Zhang B, Yang WY. Postprandial glucagon-like peptide 1 secretion is associated with urinary albumin excretion in newly diagnosed type 2 diabetes patients. World J Diabetes 2023; 14:279-289. [PMID: 37035218 PMCID: PMC10075041 DOI: 10.4239/wjd.v14.i3.279] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/21/2022] [Accepted: 02/16/2023] [Indexed: 03/15/2023] Open
Abstract
BACKGROUND Microalbuminuria is an early and informative marker of diabetic nephropathy. Our study found that microalbuminuria developed in patients with newly diagnosed type 2 diabetes mellitus (T2DM).
AIM To investigate the association between glucagon-like peptide 1 (GLP-1) and microalbuminuria in newly diagnosed T2DM patients.
METHODS In total, 760 patients were recruited for this cross-sectional study. The GLP-1 levels during a standard meal test and urinary albumin-creatinine ratio (UACR) were determined.
RESULTS Patients with microalbuminuria exhibited lower GLP-1 levels at 30 min and 120 min during a standard meal test than patients with normal albuminuria (30 min GLP-1, 16.7 ± 13.3 pmol vs 19.9 ± 15.6 pmol, P = 0.007; 120 min GLP-1, 16.0 ± 14.1 pmol vs 18.4 ± 13.8 pmol, P = 0.037). The corresponding area under the curve for active GLP-1 (AUCGLP-1) was also lower in microalbuminuria patients (2257, 1585 to 3506 vs 2896, 1763 to 4726, pmol × min, P = 0.003). Postprandial GLP-1 levels at 30 min and 120 min and AUCGLP-1 were negatively correlated with the UACR (r = 0.159, r = 0.132, r = 0.206, respectively, P < 0.001). The prevalence of microalbuminuria in patients with newly diagnosed T2DM was 21.7%, which decreased with increasing quartiles of AUCGLP-1 levels (27.4%, 25.3%, 18.9% and 15.8%). After logistic regression analysis adjusted for sex, age, hemoglobin A1c, body mass index, systolic blood pressure, estimated glomerular filtration rate, homeostasis model assessment of insulin resistance, AUCglucose and AUCglucagon, patients in quartile 4 of the AUCGLP-1 presented a lower risk of microalbuminuria compared with the patients in quartile 1 (odds ratio = 0.547, 95% confidence interval: 0.325-0.920, P = 0.01). A consistent association was also found between 30 min GLP-1 or 120 min GLP-1 and microalbuminuria.
CONCLUSION Postprandial GLP-1 levels were independently associated with microalbuminuria in newly diagnosed Chinese T2DM patients.
Collapse
Affiliation(s)
- Lu-Lu Song
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Na Wang
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jin-Ping Zhang
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Li-Ping Yu
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Xiao-Ping Chen
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Bo Zhang
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Wen-Ying Yang
- Department of Endocrinology, China-Japan Friendship Hospital, Beijing 100029, China
| |
Collapse
|
7
|
Ding C, Egli L, Bosco N, Sun L, Goh HJ, Yeo KK, Yap JJL, Actis-Goretta L, Leow MKS, Magkos F. Plasma Branched-Chain Amino Acids Are Associated With Greater Fasting and Postprandial Insulin Secretion in Non-diabetic Chinese Adults. Front Nutr 2021; 8:664939. [PMID: 33996878 PMCID: PMC8113402 DOI: 10.3389/fnut.2021.664939] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 03/30/2021] [Indexed: 12/22/2022] Open
Abstract
Background: Plasma branched-chain amino acids (BCAA) are consistently elevated in subjects with obesity and type 2 diabetes (T2DM) and correlate with insulin resistance. The association of BCAA with insulin secretion and clearance rates has not been adequately described. Objective: To evaluate the relationships between fasting and postprandial plasma BCAA, insulin secretion and insulin clearance. Design: Ninety-five non-diabetic Chinese subjects (43 females) underwent a mixed-meal tolerance test; blood biomarkers including BCAAs (leucine, isoleucine, valine) were measured for 6 h. Fasting and postprandial insulin secretion rates (ISR) and insulin clearance were determined by oral minimal modeling of glucose and C-peptide. Results: Fasting and postprandial plasma BCAA correlated strongly with each other (ρ = 0.796, P < 0.001), and both were positively associated with basal ISR (ρ = 0.45/0.36, P < 0.001), total postprandial ISR AUC (ρ = 0.37/0.45, P < 0.001), and negatively with insulin clearance (ρ = -0.29/-0.29, P < 0.01), after adjusting for sex and body mass index. These relationships largely persisted after adjusting further for insulin resistance and postprandial glucose. Compared with subjects in the middle and lowest tertiles for fasting or postprandial plasma BCAA, subjects in the highest tertile had significantly greater postprandial glucose (by 7-10%) and insulin (by 74-98%) concentrations, basal ISRs (by 34-53%), postprandial ISR AUCs (by 41-49%), and lower insulin clearance rates (by 17-22%) (all P < 0.05). Conclusions: Fasting and postprandial plasma BCAA levels are associated with greater fasting and postprandial insulin secretion and reduced insulin clearance in healthy Chinese subjects. These observations potentially highlight an additional layer of involvement of BCAA in the regulation of glucose homeostasis.
Collapse
Affiliation(s)
| | - Leonie Egli
- Nestlé Institute of Health Sciences, Nestlé Research, Lausanne, Switzerland
| | - Nabil Bosco
- Nestlé Research, Singapore, Singapore
- Nestlé Institute of Health Sciences, Nestlé Research, Lausanne, Switzerland
| | - Lijuan Sun
- Singapore Institute for Clinical Sciences, Singapore, Singapore
| | - Hui Jen Goh
- Singapore Institute for Clinical Sciences, Singapore, Singapore
| | - Khung Keong Yeo
- Duke-NUS Medical School, Singapore, Singapore
- National Heart Centre Singapore, Singapore, Singapore
| | - Jonathan Jiunn Liang Yap
- National Heart Centre Singapore, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | | | - Melvin Khee-Shing Leow
- Singapore Institute for Clinical Sciences, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore, Singapore
| | - Faidon Magkos
- Department of Nutrition, Exercise & Sports, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
8
|
Effects of Low-Carbohydrate versus Mediterranean Diets on Weight Loss, Glucose Metabolism, Insulin Kinetics and β-Cell Function in Morbidly Obese Individuals. Nutrients 2021; 13:nu13041345. [PMID: 33919503 PMCID: PMC8074206 DOI: 10.3390/nu13041345] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
Low-calorie Mediterranean-style or low-carbohydrate dietary regimens are widely used nutritional strategies against obesity and associated metabolic diseases, including type 2 diabetes. The aim of this study was to compare the effectiveness of a balanced Mediterranean diet with a low-carbohydrate diet on weight loss and glucose homeostasis in morbidly obese individuals at high risk to develop diabetes. Insulin secretion, insulin clearance, and different β-cell function components were estimated by modeling plasma glucose, insulin and C-peptide profiles during 75-g oral glucose tolerance tests (OGTTs) performed at baseline and after 4 weeks of each dietary intervention. The average weight loss was 5%, being 58% greater in the low-carbohydrate-group than Mediterranean-group. Fasting plasma glucose and glucose tolerance were not affected by the diets. The two dietary regimens proved similarly effective in improving insulin resistance and fasting hyperinsulinemia, while enhancing endogenous insulin clearance and β-cell glucose sensitivity. In summary, we demonstrated that a low-carbohydrate diet is a successful short-term approach for weight loss in morbidly obese patients and a feasible alternative to the Mediterranean diet for its glucometabolic benefits, including improvements in insulin resistance, insulin clearance and β-cell function. Further studies are needed to compare the long-term efficacy and safety of the two diets.
Collapse
|
9
|
Elovaris RA, Hajishafiee M, Ullrich SS, Fitzgerald PCE, Lange K, Horowitz M, Feinle-Bisset C. Intragastric administration of leucine and isoleucine does not reduce the glycaemic response to, or slow gastric emptying of, a carbohydrate-containing drink in type 2 diabetes. Diabetes Res Clin Pract 2021; 171:108618. [PMID: 33310174 DOI: 10.1016/j.diabres.2020.108618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 02/07/2023]
Abstract
AIMS In healthy individuals, intragastric administration of the branched-chain amino acids, leucine and isoleucine, diminishes the glycaemic response to a mixed-nutrient drink, apparently by stimulating insulin and slowing gastric emptying, respectively. This study aimed to evaluate the effects of leucine and isoleucine on postprandial glycaemia and gastric emptying in type-2 diabetes mellitus (T2D). METHODS 14 males with T2D received, on 3 separate occasions, in double-blind, randomised fashion, either 10 g leucine, 10 g isoleucine or control, intragastrically 30 min before a mixed-nutrient drink (500 kcal; 74 g carbohydrates, 18 g protein, 15 g fat). Plasma glucose, insulin and glucagon were measured from 30 min pre- until 120 min post-drink. Gastric emptying of the drink was also measured. RESULTS Leucine and isoleucine stimulated insulin, both before and after the drink (all P < 0.05; peak (mU/L): control: 70 ± 15; leucine: 88 ± 17; isoleucine: 74 ± 15). Isoleucine stimulated (P < 0.05), and leucine tended to stimulate (P = 0.078), glucagon before the drink, and isoleucine stimulated glucagon post-drink (P = 0.031; peak (pg/mL): control: 62 ± 5; leucine: 70 ± 9; isoleucine: 69 ± 6). Neither amino acid affected gastric emptying or plasma glucose (peak (mmol/L): control: 12.0 ± 0.5; leucine: 12.5 ± 0.7; isoleucine: 12.0 ± 0.6). CONCLUSIONS In contrast to health, in T2D, leucine and isoleucine, administered intragastrically in a dose of 10 g, do not lower the glycaemic response to a mixed-nutrient drink. This finding argues against a role for 'preloads' of either leucine or isoleucine in the management of T2D.
Collapse
Affiliation(s)
- Rachel A Elovaris
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia
| | - Maryam Hajishafiee
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia
| | - Sina S Ullrich
- Department of Clinical Research, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Penelope C E Fitzgerald
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia
| | - Kylie Lange
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia
| | - Michael Horowitz
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia
| | - Christine Feinle-Bisset
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, University of Adelaide, Adelaide, Australia.
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW In this review, the latest evidence on the influence of dietary protein and plasma amino acids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is discussed. RECENT FINDINGS Increasing protein consumption during weight loss and maintenance may help reduce liver fat content. Conversely, high protein intake characteristic of the unhealthy Western diet is associated with increased NAFLD prevalence and severity. Plasma concentration of several amino acids, including branched-chain (BCAA) and aromatic amino acids (AAA), is altered in NAFLD. Excess amino acid availability contributes to intrahepatic fat accumulation and may reflect poor dietary habits and dysregulation of amino acid metabolic processing in both liver and peripheral tissues. Specific amino acid patterns, characterized by increased BCAA, AAA, alanine, glutamate, lysine levels, and decreased glycine and serine levels, may be used for early detection of NAFLD and noninvasive assessment of its histological severity. SUMMARY Mechanistic studies in NAFLD have been mostly focused on carbohydrate and fat metabolism, while little is known about the influence of protein and amino acids. Moreover, intervention and observational studies on the relation between protein intake and NAFLD yielded conflicting results. Filling the current knowledge gaps would help define the optimal diet composition for NAFLD prevention and management. Furthermore, metabolomics studies may provide insight into the pathogenesis of NAFLD, identify useful diagnostic and prognostic biomarkers, and unravel novel pharmacological targets and treatment options.
Collapse
Affiliation(s)
- Domenico Tricò
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa
- Institute of Life Sciences, Sant'Anna School of Advanced Studies
| | - Edoardo Biancalana
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Anna Solini
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa
| |
Collapse
|
11
|
Kamruzzaman M, Horowitz M, Jones KL, Marathe CS. Gut-Based Strategies to Reduce Postprandial Glycaemia in Type 2 Diabetes. Front Endocrinol (Lausanne) 2021; 12:661877. [PMID: 33897622 PMCID: PMC8062751 DOI: 10.3389/fendo.2021.661877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/16/2021] [Indexed: 02/05/2023] Open
Abstract
Postprandial glycemic control is an important target for optimal type 2 diabetes management, but is often difficult to achieve. The gastrointestinal tract plays a major role in modulating postprandial glycaemia in both health and diabetes. The various strategies that have been proposed to modulate gastrointestinal function, particularly by slowing gastric emptying and/or stimulating incretin hormone GLP-1, are summarized in this review.
Collapse
Affiliation(s)
- Md Kamruzzaman
- Department of Applied Nutrition and Food Technology, Islamic University, Kushtia, Bangladesh
| | - Michael Horowitz
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Karen L. Jones
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Chinmay S. Marathe
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
- *Correspondence: Chinmay S. Marathe,
| |
Collapse
|
12
|
Smith K, Bowden Davies KA, Stevenson EJ, West DJ. The Clinical Application of Mealtime Whey Protein for the Treatment of Postprandial Hyperglycaemia for People With Type 2 Diabetes: A Long Whey to Go. Front Nutr 2020; 7:587843. [PMID: 33195375 PMCID: PMC7607659 DOI: 10.3389/fnut.2020.587843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/15/2020] [Indexed: 12/11/2022] Open
Abstract
Mitigating postprandial hyperglycaemic excursions may be effective in not only enhancing glycaemic control for people with type 2 diabetes but also reducing the onset of diabetes-related complications. However, there are growing concerns over the long-term efficacy of anti-hyperglycaemic pharmacotherapies, which coupled with their rising financial costs, underlines the need for further non-pharmaceutical treatments to regulate postprandial glycaemic excursions. One promising strategy that acutely improves postprandial glycaemia for people with type 2 diabetes is through the provision of mealtime whey protein, owing to the slowing of gastric emptying and increased secretion of insulin and the incretin peptides. The magnitude of this effect appears greater when whey protein is consumed before, rather than with, a meal. Herein, this dietary tool may offer a simple and inexpensive strategy in the management of postprandial hyperglycaemia for people with type 2 diabetes. However, there are insufficient long-term studies that have investigated the use of mealtime whey protein as a treatment option for individuals with type 2 diabetes. The methodological approaches applied in acute studies and outcomes reported may also not portray what is achievable long-term in practice. Therefore, studies are needed to refine the application of this mealtime strategy to maximize its clinical potential to treat hyperglycaemia and to apply these long-term to address key components of successful diabetes care. This review discusses evidence surrounding the provision of mealtime whey protein to treat postprandial hyperglycaemia in individuals with type 2 diabetes and highlights areas to help facilitate its clinical application.
Collapse
Affiliation(s)
- Kieran Smith
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kelly A Bowden Davies
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.,Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, United Kingdom
| | - Emma J Stevenson
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Daniel J West
- Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| |
Collapse
|
13
|
Dietary intake of specific amino acids and liver status in subjects with nonalcoholic fatty liver disease: fatty liver in obesity (FLiO) study. Eur J Nutr 2020; 60:1769-1780. [PMID: 32857176 DOI: 10.1007/s00394-020-02370-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/19/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE Identification of dietary factors involved in the development and progression of nonalcoholic fatty liver disease (NAFLD) is relevant to the current epidemics of the disease. Dietary amino acids appear to play a key role in the onset and progression of NAFLD. The aim of this study was to analyze potential associations between specific dietary amino acids and variables related to glucose metabolism and hepatic status in adults with overweight/obesity and NAFLD. METHODS One hundred and twelve individuals from the Fatty Liver in Obesity (FLiO) study were evaluated. Liver assessment was carried out by ultrasonography, magnetic resonance imaging and analysis of biochemical parameters. Dietary amino acid intake (aromatic amino acids (AAA); branched-chain amino acids (BCAA); sulfur amino acids (SAA)) was estimated by means of a validated 137-item food frequency questionnaire. RESULTS Higher consumption of these amino acids was associated with worse hepatic health. Multiple adjusted regression models confirmed that dietary AAA, BCAA and SAA were positively associated with liver fat content. AAA and BCAA were positively associated with liver iron concentration. Regarding ferritin levels, a positive association was found with BCAA. Dietary intake of these amino acids was positively correlated with glucose metabolism (glycated hemoglobin, triglyceride and glucose index) although the significance disappeared when potential confounders were included in the model. CONCLUSION These findings suggest that the consumption of specific dietary amino acids might negatively impact on liver status and, to a lesser extent on glucose metabolism in subjects with overweight/obesity and NAFLD. A control of specific dietary amino acid composition should be considered in the management of NAFLD and associated insulin resistance. NCT03183193; June 2017.
Collapse
|
14
|
Minderis P, Fokin A, Dirmontas M, Ratkevicius A. Hypocaloric Low-Carbohydrate and Low-Fat Diets with Fixed Protein Lead to Similar Health Outcomes in Obese Mice. Obesity (Silver Spring) 2020; 28:1494-1502. [PMID: 32639096 DOI: 10.1002/oby.22872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/21/2022]
Abstract
OBJECTIVE It is controversial whether low-carbohydrate diets are better suited for weight control and metabolic health than high-carbohydrate diets. This study examined whether these diets induce different improvements in body composition and glucose tolerance in obese mice during caloric restriction (CR). METHODS Male C57BL/6J mice were fed an obesogenic diet ad libitum for 18 weeks and then subjected to 6-week progressive CR of up to 40%, using either a low-fat or low-carbohydrate diet with equal protein content. Mice fed a regular chow diet ad libitum served as controls. Body mass, hindlimb muscle mass, fat mass, energy expenditure, and glucose tolerance were compared between the groups. RESULTS Initially low-fat and low-carbohydrate groups had similar body mass, which was 30% greater compared with controls. CR induced similar weight loss in low-fat and low-carbohydrate groups. This weight loss was mainly due to fat loss in both groups. Energy expenditure of freely moving mice did not differ between the groups. Glucose tolerance improved compared with the values before CR and in controls but did not differ between the diets. CONCLUSIONS Dietary carbohydrate or fat content does not affect improvements in body composition and metabolic health in obese mice exposed to CR with fixed energy and protein intake.
Collapse
Affiliation(s)
- Petras Minderis
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Andrej Fokin
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Mantas Dirmontas
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Aivaras Ratkevicius
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania
| |
Collapse
|
15
|
A Protein/Lipid Preload Attenuates Glucose-Induced Endothelial Dysfunction in Individuals with Abnormal Glucose Tolerance. Nutrients 2020; 12:nu12072053. [PMID: 32664350 PMCID: PMC7400934 DOI: 10.3390/nu12072053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/24/2020] [Accepted: 07/08/2020] [Indexed: 12/24/2022] Open
Abstract
Postprandial hyperglycemia interferes with vascular reactivity and is a strong predictor of cardiovascular disease. Macronutrient preloads reduce postprandial hyperglycemia in subjects with impaired glucose tolerance (IGT) or type 2 diabetes (T2D), but the effect on endothelial function is unknown. Therefore, we examined whether a protein/lipid preload can attenuate postprandial endothelial dysfunction by lowering plasma glucose responses in subjects with IGT/T2D. Endothelial function was assessed by the reactive hyperemia index (RHI) at fasting, 60 min and 120 min during two 75 g oral glucose tolerance tests (OGTTs) preceded by either water or a macronutrient preload (i.e., egg and parmesan cheese) in 22 volunteers with IGT/T2D. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), glucagon, free fatty acids, and amino acids were measured through each test. RHI negatively correlated with fasting plasma glucose. During the control OGTT, RHI decreased by 9% and its deterioration was associated with the rise in plasma glucose. The macronutrient preload attenuated the decline in RHI and markedly reduced postprandial glycemia. The beneficial effect of the macronutrient preload on RHI was proportional to the improvement in glucose tolerance and was associated with the increase in plasma GLP-1 and arginine levels. In conclusion, a protein/lipid macronutrient preload attenuates glucose-induced endothelial dysfunction in individuals with IGT/T2D by lowering plasma glucose excursions and by increasing GLP-1 and arginine levels, which are known regulators of the nitric oxide vasodilator system.
Collapse
|
16
|
Churuangsuk C, Lean MEJ, Combet E. Low and reduced carbohydrate diets: challenges and opportunities for type 2 diabetes management and prevention. Proc Nutr Soc 2020; 79:1-16. [PMID: 32131904 DOI: 10.1017/s0029665120000105] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Low-carbohydrate diets (LCD) have been promoted for weight control and type 2 diabetes (T2D) management, based on an emerging body of evidence, including meta-analyses with an indication of publication bias. Proposed definitions vary between 50 and 130 g/d, or <10 and <40 % of energy from carbohydrate, with no consensus on LCD compositional criteria. LCD are usually followed with limited consideration for other macronutrients in the overall diet composition, introducing variance in the constituent foods and in metabolic responses. For weight management, extensive evidence supports LCD as a valid weight loss treatment, up to 1-2 years. Solely lowering carbohydrate intake does not, in the medium/long term, reduce HbA1c for T2D prevention or treatment, as many mechanisms interplay. Under controlled feeding conditions, LCD are not physiologically or clinically superior to diets with higher carbohydrates for weight-loss, fat loss, energy expenditure or glycaemic outcomes; indeed, all metabolic improvements require weight loss. Long-term evidence also links the LCD pattern to increased CVD risks and mortality. LCD can lead to micronutrient deficiencies and increased LDL-cholesterol, depending on food selection to replace carbohydrates. Evidence is limited but promising regarding food choices/sources to replace high-carbohydrate foods that may alleviate the negative effects of LCD, demanding further insight into the dietary practice of medium to long term LCD followers. Long-term, high-quality studies of LCD with different food sources (animal and/or plant origins) are needed, aiming for clinical endpoints (T2D incidence and remission, cardiovascular events, mortality). Ensuring micronutrient adequacy by food selection or supplementation should be considered for people who wish to pursue long-term LCD.
Collapse
Affiliation(s)
- Chaitong Churuangsuk
- Human Nutrition, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, GlasgowG31 2ER, UK
- Division of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
| | - Michael E J Lean
- Human Nutrition, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, GlasgowG31 2ER, UK
| | - Emilie Combet
- Human Nutrition, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, GlasgowG31 2ER, UK
| |
Collapse
|
17
|
Prentki M, Peyot ML, Masiello P, Madiraju SRM. Nutrient-Induced Metabolic Stress, Adaptation, Detoxification, and Toxicity in the Pancreatic β-Cell. Diabetes 2020; 69:279-290. [PMID: 32079704 DOI: 10.2337/dbi19-0014] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/20/2019] [Indexed: 11/13/2022]
Abstract
Paraphrasing the Swiss physician and father of toxicology Paracelsus (1493-1541) on chemical agents used as therapeutics, "the dose makes the poison," it is now realized that this aptly applies to the calorigenic nutrients. The case here is the pancreatic islet β-cell presented with excessive levels of nutrients such as glucose, lipids, and amino acids. The short-term effects these nutrients exert on the β-cell are enhanced insulin biosynthesis and secretion and changes in glucose sensitivity. However, chronic fuel surfeit triggers additional compensatory and adaptive mechanisms by β-cells to cope with the increased insulin demand or to protect itself. When these mechanisms fail, toxicity due to the nutrient surplus ensues, leading to β-cell dysfunction, dedifferentiation, and apoptosis. The terms glucotoxicity, lipotoxicity, and glucolipotoxicity have been widely used, but there is some confusion as to what they mean precisely and which is most appropriate for a given situation. Here we address the gluco-, lipo-, and glucolipo-toxicities in β-cells by assessing the evidence both for and against each of them. We also discuss potential mechanisms and defend the view that many of the identified "toxic" effects of nutrient excess, which may also include amino acids, are in fact beneficial adaptive processes. In addition, candidate fuel-excess detoxification pathways are evaluated. Finally, we propose that a more general term should be used for the in vivo situation of overweight-associated type 2 diabetes reflecting both the adaptive and toxic processes to mixed calorigenic nutrients excess: "nutrient-induced metabolic stress" or, in brief, "nutri-stress."
Collapse
Affiliation(s)
- Marc Prentki
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Marie-Line Peyot
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Pellegrino Masiello
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - S R Murthy Madiraju
- Departments of Nutrition and Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| |
Collapse
|
18
|
Elovaris RA, Hutchison AT, Lange K, Horowitz M, Feinle-Bisset C, Luscombe-Marsh ND. Plasma Free Amino Acid Responses to Whey Protein and Their Relationships with Gastric Emptying, Blood Glucose- and Appetite-Regulatory Hormones and Energy Intake in Lean Healthy Men. Nutrients 2019; 11:nu11102465. [PMID: 31618863 PMCID: PMC6835323 DOI: 10.3390/nu11102465] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/01/2019] [Accepted: 10/09/2019] [Indexed: 02/07/2023] Open
Abstract
This study determined the effects of increasing loads of whey protein on plasma amino acid (AA) concentrations, and their relationships with gastric emptying, blood glucose- and appetite-regulatory hormones, blood glucose and energy intake. Eighteen healthy lean men participated in a double-blinded study, in which they consumed, on 3 separate occasions, in randomised order, 450-mL drinks containing either 30 g (L) or 70 g (H) of pure whey protein isolate, or control with 0 g of protein (C). Gastric emptying, serum concentrations of AAs, ghrelin, cholecystokinin (CCK), glucagon-like-peptide 1 (GLP-1), insulin, glucagon and blood glucose were measured before and after the drinks over 180 min. Then energy intake was quantified. All AAs were increased, and 7/20 AAs were increased more by H than L. Incremental areas under the curve (iAUC0-180 min) for CCK, GLP-1, insulin and glucagon were correlated positively with iAUCs of 19/20 AAs (p < 0.05). The strongest correlations were with the branched-chain AAs as well as lysine, tyrosine, methionine, tryptophan, and aspartic acid (all R2 > 0.52, p < 0.05). Blood glucose did not correlate with any AA (all p > 0.05). Ghrelin and energy intake correlated inversely, but only weakly, with 15/20 AAs (all R2 < 0.34, p < 0.05). There is a strong relationship between gluco-regulatory hormones with a number of (predominantly essential) AAs. However, the factors mediating the effects of protein on blood glucose and energy intake are likely to be multifactorial.
Collapse
Affiliation(s)
- Rachel A Elovaris
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
| | - Amy T Hutchison
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
- Nutrition and Metabolism Theme, South Australian Health and Medical Research Institute, Adelaide 5000, Australia.
| | - Kylie Lange
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
| | - Michael Horowitz
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
| | - Christine Feinle-Bisset
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
| | - Natalie D Luscombe-Marsh
- Adelaide Medical School and National Health and Medical Research Council of Australia Centre of Research Excellence in Translating Nutritional Science to Good Health, Adelaide Health and Medical Sciences Building, Corner North Terrace and George Street, Adelaide 5005, Australia.
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Nutrition and Health Program, P.O. Box 10097, Adelaide 5000, Australia.
| |
Collapse
|
19
|
Modvig IM, Kuhre RE, Holst JJ. Peptone-mediated glucagon-like peptide-1 secretion depends on intestinal absorption and activation of basolaterally located Calcium-Sensing Receptors. Physiol Rep 2019; 7:e14056. [PMID: 31020803 PMCID: PMC6482282 DOI: 10.14814/phy2.14056] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/15/2019] [Accepted: 03/16/2019] [Indexed: 01/13/2023] Open
Abstract
Protein intake robustly stimulates the secretion of the incretin hormone, glucagon-like peptide-1 (GLP-1) but the molecular mechanisms involved are not well understood. In particular, it is unknown whether proteins stimulate secretion by activation of luminal or basolateral sensors. We characterized the mechanisms using a physiologically relevant model - the isolated perfused proximal rat small intestine. Intraluminal protein hydrolysates derived from meat (peptone; 50 mg/mL) increased GLP-1 secretion 2.3-fold (from a basal secretion of 110 ± 28 fmol/min). The sensory mechanisms underlying the response depended on di/tripeptide uptake through Peptide Transporter 1 (PepT1) and subsequent basolateral activation of the amino acid sensing receptor, Calcium-Sensing Receptor (CaSR), since inhibition of PepT1 as well as CaSR both attenuated the peptone-induced GLP-1 response. Supporting this, intraluminal peptones were absorbed efficiently by the perfused intestine (resulting in increased amino acid concentrations in the venous effluent) and infusion of amino acids robustly stimulated GLP-1 secretion. Inhibitors of voltage-gated L-type Ca2+ channels had no effect on secretion suggesting that peptone-mediated GLP-1 secretion is not mediated by L-cell depolarization with subsequent opening of these channels. Specific targeting of CaSR could serve as a target to stimulate the endogenous secretion of GLP-1.
Collapse
Affiliation(s)
- Ida M. Modvig
- Department of Biomedical SciencesNNF Center for Basic Metabolic ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Rune E. Kuhre
- Department of Biomedical SciencesNNF Center for Basic Metabolic ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jens Juul Holst
- Department of Biomedical SciencesNNF Center for Basic Metabolic ResearchFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| |
Collapse
|
20
|
Melnik BC, Schmitz G. Exosomes of pasteurized milk: potential pathogens of Western diseases. J Transl Med 2019; 17:3. [PMID: 30602375 PMCID: PMC6317263 DOI: 10.1186/s12967-018-1760-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 12/21/2018] [Indexed: 12/16/2022] Open
Abstract
Milk consumption is a hallmark of western diet. According to common believes, milk consumption has beneficial effects for human health. Pasteurization of cow's milk protects thermolabile vitamins and other organic compounds including bioactive and bioavailable exosomes and extracellular vesicles in the range of 40-120 nm, which are pivotal mediators of cell communication via systemic transfer of specific micro-ribonucleic acids, mRNAs and regulatory proteins such as transforming growth factor-β. There is compelling evidence that human and bovine milk exosomes play a crucial role for adequate metabolic and immunological programming of the newborn infant at the beginning of extrauterine life. Milk exosomes assist in executing an anabolic, growth-promoting and immunological program confined to the postnatal period in all mammals. However, epidemiological and translational evidence presented in this review indicates that continuous exposure of humans to exosomes of pasteurized milk may confer a substantial risk for the development of chronic diseases of civilization including obesity, type 2 diabetes mellitus, osteoporosis, common cancers (prostate, breast, liver, B-cells) as well as Parkinson's disease. Exosomes of pasteurized milk may represent new pathogens that should not reach the human food chain.
Collapse
Affiliation(s)
- Bodo C. Melnik
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Am Finkenhügel 7A, 49076 Osnabrück, Germany
| | - Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, University of Regensburg, Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| |
Collapse
|
21
|
Nesti L, Mengozzi A, Tricò D. Impact of Nutrient Type and Sequence on Glucose Tolerance: Physiological Insights and Therapeutic Implications. Front Endocrinol (Lausanne) 2019; 10:144. [PMID: 30906282 PMCID: PMC6418004 DOI: 10.3389/fendo.2019.00144] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/18/2019] [Indexed: 02/03/2023] Open
Abstract
Pharmacological and dietary interventions targeting postprandial glycemia have proved effective in reducing the risk for type 2 diabetes and its cardiovascular complications. Besides meal composition and size, the timing of macronutrient consumption during a meal has been recently recognized as a key regulator of postprandial glycemia. Emerging evidence suggests that premeal consumption of non-carbohydrate macronutrients (i.e., protein and fat "preloads") can markedly reduce postprandial glycemia by delaying gastric emptying, enhancing glucose-stimulated insulin release, and decreasing insulin clearance. The same improvement in glucose tolerance is achievable by optimal timing of carbohydrate ingestion during a meal (i.e., carbohydrate-last meal patterns), which minimizes the risk of body weight gain when compared with nutrient preloads. The magnitude of the glucose-lowering effect of preload-based nutritional strategies is greater in type 2 diabetes than healthy subjects, being comparable and additive to current glucose-lowering drugs, and appears sustained over time. This dietary approach has also shown promising results in pathological conditions characterized by postprandial hyperglycemia in which available pharmacological options are limited or not cost-effective, such as type 1 diabetes, gestational diabetes, and impaired glucose tolerance. Therefore, preload-based nutritional strategies, either alone or in combination with pharmacological treatments, may offer a simple, effective, safe, and inexpensive tool for the prevention and management of postprandial hyperglycemia. Here, we survey these novel physiological insights and their therapeutic implications for patients with diabetes mellitus and altered glucose tolerance.
Collapse
Affiliation(s)
- Lorenzo Nesti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Alessandro Mengozzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Domenico Tricò
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Sant'Anna School of Advanced Studies, Institute of Life Sciences, Pisa, Italy
- *Correspondence: Domenico Tricò
| |
Collapse
|
22
|
Guess ND. Dietary Interventions for the Prevention of Type 2 Diabetes in High-Risk Groups: Current State of Evidence and Future Research Needs. Nutrients 2018; 10:E1245. [PMID: 30200572 PMCID: PMC6163866 DOI: 10.3390/nu10091245] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/28/2018] [Accepted: 08/30/2018] [Indexed: 12/13/2022] Open
Abstract
A series of large-scale randomised controlled trials have demonstrated the effectiveness of lifestyle change in preventing type 2 diabetes in people with impaired glucose tolerance. Participants in these trials consumed a low-fat diet, lost a moderate amount of weight and/or increased their physical activity. Weight loss appears to be the primary driver of type 2 diabetes risk reduction, with individual dietary components playing a minor role. The effect of weight loss via other dietary approaches, such as low-carbohydrate diets, a Mediterranean dietary pattern, intermittent fasting or very-low-energy diets, on the incidence of type 2 diabetes has not been tested. These diets-as described here-could be equally, if not more effective in preventing type 2 diabetes than the tested low-fat diet, and if so, would increase choice for patients. There is also a need to understand the effect of foods and diets on beta-cell function, as the available evidence suggests moderate weight loss, as achieved in the diabetes prevention trials, improves insulin sensitivity but not beta-cell function. Finally, prediabetes is an umbrella term for different prediabetic states, each with distinct underlying pathophysiology. The limited data available question whether moderate weight loss is effective at preventing type 2 diabetes in each of the prediabetes subtypes.
Collapse
Affiliation(s)
- Nicola D Guess
- Department of Nutritional Sciences, King's College London, 150 Stamford Street, Room 4.13, London SE1 9NH, UK.
| |
Collapse
|