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Insulin clearance and incretin hormones following oral and "isoglycemic" intravenous glucose in type 2 diabetes patients under different antidiabetic treatments. Sci Rep 2022; 12:2510. [PMID: 35169165 PMCID: PMC8847358 DOI: 10.1038/s41598-022-06402-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/09/2021] [Indexed: 12/14/2022] Open
Abstract
It has not been elucidated whether incretins affect insulin clearance in type 2 diabetes (T2D). We aimed exploring possible associations between insulin clearance and endogenously secreted or exogenously administered incretins in T2D patients. Twenty T2D patients were studied (16 males/4 females, 59 ± 2 years (mean ± standard error), BMI = 31 ± 1 kg/m2, HbA1c = 7.0 ± 0.1%). Patients were treated with metformin, sitagliptin, metformin/sitagliptin combination, and placebo (randomized order). On each treatment period, oral and isoglycemic intravenous glucose infusion tests were performed (OGTT, IIGI, respectively). We also studied twelve T2D patients (9 males/3 females, 61 ± 3 years, BMI = 30 ± 1 kg/m2, HbA1c = 7.3 ± 0.4%) that underwent infusion of GLP-1(7–36)-amide, GIP, GLP-1/GIP combination, and placebo. Plasma glucose, insulin, C-peptide, and incretins were measured. Insulin clearance was assessed as insulin secretion to insulin concentration ratio. In the first study, we found OGTT/IIGI insulin clearance ratio weakly inversely related to OGTT/IIGI total GIP and intact GLP-1 (R2 = 0.13, p < 0.02). However, insulin clearance showed some differences between sitagliptin and metformin treatment (p < 0.02). In the second study we found no difference in insulin clearance following GLP-1 and/or GIP infusion (p > 0.5). Thus, our data suggest that in T2D there are no relevant incretin effects on insulin clearance. Conversely, different antidiabetic treatments may determine insulin clearance variations.
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Determinants of hepatic insulin clearance - Results from a Mendelian Randomization study. Metabolism 2021; 119:154776. [PMID: 33862045 DOI: 10.1016/j.metabol.2021.154776] [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: 01/15/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 11/22/2022]
Abstract
AIMS/HYPOTHESIS Besides insulin resistance, type 2 diabetes associates with decreased hepatic insulin clearance (HIC). We now tested for causal relationship of HIC to liver fat accumulation or features of the metabolic syndrome. METHODS HIC was derived from oral glucose tolerance tests with the "Oral C-peptide and Insulin Minimal Models" (n = 3311). Liver fat was quantified by magnetic resonance spectroscopy (n = 1211). Mendelian Randomization was performed using established single nucleotide polymorphisms (SNPs; 115 for liver fat, 155 alanine-aminotransferase, 37 insulin sensitivity, 37 insulin secretion, 72 fasting insulin, 5285 BMI, 163 visceral fat, 270 waist circumference, 442 triglycerides, 620 HDL-Cholesterol, 193 C-reactive protein, 53 lipodystrophy-like phenotypes). RESULTS HIC associated inversely with liver fat (p < 0.003) and insulin sensitivity (p < 0.0001). Both liver fat and HIC were independently associated with insulin sensitivity (p < 0.0001). Neither liver fat nor alanine-aminotransferase were causally linked to HIC, as indicated by Mendelian Randomization (Nliver fat = 1054, NHIC = 2254; Nalanineaminotranferase = 1985, NHIC = 2251). BMI-related SNPs were causally associated with HIC (NBMI = 2772, NHIC = 2259, p < 0.001) but not waist circumference-SNPs (NSNPs-waist circumference = 2751, NHIC = 2280). Genetically determined insulin sensitivity was not causally related to HIC (Ninsulin sensitivity = 2752, NHIC = 2286). C-reactive protein and HDL were causally associated with HIC, with higher C-reactive protein and lower HDL leading to higher HIC (NC-reactive protein = 2660, NHIC = 2240; NHDL = 2694, NHIC = 2275). CONCLUSIONS This Mendelian Randomization analysis does not support a causal link between hepatic steatosis and HIC. Other components of the metabolic syndrome seem to compensate peripheral hyperinsulinemia by increasing hepatic insulin extraction.
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Targeting Insulin-Degrading Enzyme in Insulin Clearance. Int J Mol Sci 2021; 22:ijms22052235. [PMID: 33668109 PMCID: PMC7956289 DOI: 10.3390/ijms22052235] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/20/2021] [Accepted: 02/21/2021] [Indexed: 02/07/2023] Open
Abstract
Hepatic insulin clearance, a physiological process that in response to nutritional cues clears ~50–80% of circulating insulin, is emerging as an important factor in our understanding of the pathogenesis of type 2 diabetes mellitus (T2DM). Insulin-degrading enzyme (IDE) is a highly conserved Zn2+-metalloprotease that degrades insulin and several other intermediate-size peptides. Both, insulin clearance and IDE activity are reduced in diabetic patients, albeit the cause-effect relationship in humans remains unproven. Because historically IDE has been proposed as the main enzyme involved in insulin degradation, efforts in the development of IDE inhibitors as therapeutics in diabetic patients has attracted attention during the last decades. In this review, we retrace the path from Mirsky’s seminal discovery of IDE to the present, highlighting the pros and cons of the development of IDE inhibitors as a pharmacological approach to treating diabetic patients.
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Association of Basal Metabolic Rate and Nutrients Oxidation with Cardiometabolic Risk Factors and Insulin Sensitivity in Sedentary Middle-Aged Adults. Nutrients 2020; 12:nu12041186. [PMID: 32340248 PMCID: PMC7230721 DOI: 10.3390/nu12041186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/15/2020] [Accepted: 04/23/2020] [Indexed: 01/03/2023] Open
Abstract
This cross-sectional study aimed to examine the association of basal metabolic rate (BMR) and basal fat and carbohydrate oxidation (BFox and BCHox, respectively) with cardiometabolic risk factors and insulin sensitivity in sedentary middle-aged adults. A total of 71 healthy sedentary adults (37 women) aged 40–65 years participated in the current study. Data were collected during the baseline assessments of the FIT-AGEING randomized controlled trial. BMR was measured via indirect calorimetry, and BFox and BCHox estimated by stoichiometric equations. Blood pressure, glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides plasma levels were selected as cardiometabolic risk factors and assessed following standard procedures. We observed positive associations of BMR with plasma insulin and the homeostatic model assessment of insulin resistance index (HOMA; all p < 0.05) which were attenuated or disappeared after controlling by sex, age, and/or lean mass. There were positive associations between BFox and the quantitative insulin sensitivity check index (QUICKI; p < 0.015), while negative associations were noted between BFox and plasma insulin and HOMA (p < 0.015). There was a significant negative association between BCHox with QUICKI (p < 0.01), whereas significant positive relationships were obtained when BCHox was associated with plasma insulin and HOMA (p < 0.01). These associations persisted in almost all cases when controlling by sex, age and/or lean mass. No further relationships were found when BMR, BFox, and BCHox were associated with other cardiometabolic risk factors. In conclusion, our study findings support that greater BFox and lower BCHox are related to improved insulin sensitivity, whereas BMR seems to be not associated with neither cardiometabolic risk nor insulin sensitivity in sedentary middle-aged adults. Further intervention studies are necessary to well-understand the physiological mechanism implied in this relationship.
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Elevated insulin levels following 7 days of increased sedentary time are due to lower hepatic extraction and not higher insulin secretion. Appl Physiol Nutr Metab 2019; 44:1020-1023. [PMID: 30970217 DOI: 10.1139/apnm-2018-0802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Higher insulin following sedentary behavior may be due to increased insulin secretion (IS), decreased hepatic insulin extraction (HIE), or a combination of both. Ten healthy adults completed glucose tolerance tests following 7 days of normal activity and 7 days of increased sitting. There were no differences in IS; however, HIE at 120 min after ingestion (85.4% ± 7.2% vs. 74.6% ± 6.6%, p < 0.05) and the area under the curve (73.6% ± 9.4% vs. 67.5% ± 11.3%, p < 0.05) were reduced following 7 days of increased sedentary time.
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Determinants of longitudinal change in insulin clearance: the Prospective Metabolism and Islet Cell Evaluation cohort. BMJ Open Diabetes Res Care 2019; 7:e000825. [PMID: 31803485 PMCID: PMC6887510 DOI: 10.1136/bmjdrc-2019-000825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/03/2019] [Accepted: 10/28/2019] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE To evaluate multiple determinants of the longitudinal change in insulin clearance (IC) in subjects at high risk for type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Adults (n=492) at risk for T2D in the Prospective Metabolism and Islet Cell Evaluation cohort, a longitudinal observational cohort, had four visits over 9 years. Values from oral glucose tolerance tests collected at each assessment were used to calculate the ratios of both fasting C peptide-to-insulin (ICFASTING) and areas under the curve of C peptide-to-insulin (ICAUC). Generalized estimating equations (GEE) evaluated multiple determinants of longitudinal changes in IC. RESULTS IC declined by 20% over the 9-year follow-up period (p<0.05). Primary GEE results indicated that non-European ethnicity, as well as increases in baseline measures of waist circumference, white cell count, and alanine aminotransferase, was associated with declines in ICFASTING and ICAUC over time (all p<0.05). There were no significant associations of IC with sex, age, physical activity, smoking, or family history of T2D. Both baseline and longitudinal IC were associated with incident dysglycemia. CONCLUSIONS Our findings suggest that non-European ethnicity and components of the metabolic syndrome, including central obesity, non-alcoholic fatty liver disease, and subclinical inflammation, may be related to longitudinal declines in IC.
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Plasma HDL-cholesterol and triglycerides, but not LDL-cholesterol, are associated with insulin secretion in non-diabetic subjects. Metabolism 2017; 69:33-42. [PMID: 28285650 DOI: 10.1016/j.metabol.2017.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 12/15/2016] [Accepted: 01/03/2017] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Experimental data support the notion that lipoproteins might directly affect beta cell function, however clinical data are sparse and inconsistent. We aimed at verifying whether, independently of major confounders, serum lipids are associated with alterations in insulin secretion or clearance non-diabetic subjects. METHODS Cross sectional and observational prospective (3.5yrs), multicentre study in which 1016 non-diabetic volunteers aged 30-60yrs. and with a wide range of BMI (20.0-39.9kg/m2) were recruited in a setting of University hospital ambulatory care (RISC study). MAIN OUTCOME MEASURES baseline fasting lipids, fasting and OGTT-induced insulin secretion and clearance (measured by glucose and C-peptide modeling), peripheral insulin sensitivity (by the euglycemic clamp). Lipids and OGTT were repeated in 980 subjects after 3.5years. RESULTS LDL-cholesterol did not show independent associations with fasting or stimulated insulin secretion or clearance. After accounting for potential confounders, HDL-cholesterol displayed negative and triglycerides positive independent associations with fasting and OGTT insulin secretion; neither with insulin clearance. Low HDL-cholesterol and high triglycerides were associated with an increase in glucose-dependent and a decrease in non-glucose-dependent insulin secretion. Over 3.5years both an HDL-cholesterol decline and a triglycerides rise were associated with an increase in fasting insulin secretion independent of changes in body weight or plasma glucose. CONCLUSIONS LDL-cholesterol does not seem to influence any major determinant of insulin bioavailability while low HDL-cholesterol and high triglycerides might contribute to sustain the abnormalities in insulin secretion that characterize the pre-diabetic state.
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Insulin Clearance Is Associated with Hepatic Lipase Activity and Lipid and Adiposity Traits in Mexican Americans. PLoS One 2016; 11:e0166263. [PMID: 27846285 PMCID: PMC5112869 DOI: 10.1371/journal.pone.0166263] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/25/2016] [Indexed: 12/18/2022] Open
Abstract
Reduction in insulin clearance plays an important role in the compensatory response to insulin resistance. Given the importance of this trait to the pathogenesis of diabetes, a deeper understanding of its regulation is warranted. Our goal was to identify metabolic and cardiovascular traits that are independently associated with metabolic clearance rate of insulin (MCRI). We conducted a cross-sectional analysis of metabolic and cardiovascular traits in 765 participants from the Mexican-American Coronary Artery Disease (MACAD) project who had undergone blood sampling, oral glucose tolerance test, euglycemic-hyperinsulinemic clamp, dual-energy X-ray absorptiometry, and carotid ultrasound. We assessed correlations of MCRI with traits from seven domains, including anthropometry, biomarkers, cardiovascular, glucose homeostasis, lipase activity, lipid profile, and liver function tests. We found inverse independent correlations between MCRI and hepatic lipase (P = 0.0004), insulin secretion (P = 0.0002), alanine aminotransferase (P = 0.0045), total fat mass (P = 0.014), and diabetes (P = 0.03). MCRI and apolipoprotein A-I exhibited a positive independent correlation (P = 0.035). These results generate a hypothesis that lipid and adiposity associated traits related to liver function may play a role in insulin clearance.
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Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study. Nutrients 2016; 8:nu8110687. [PMID: 27809219 PMCID: PMC5133075 DOI: 10.3390/nu8110687] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/19/2016] [Accepted: 10/25/2016] [Indexed: 11/28/2022] Open
Abstract
Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal or a dairy/chicken/nuts/wholegrain meal after four weeks of the matching diet. After a three-week washout period and four weeks of the alternate diet, they consumed the matching meal. The diets differed with respect to both protein and carbohydrate sources. Blood samples were taken for 180 min for the measurement of glucose, insulin, C-peptide and triglyceride. Fifty-one participants (age: 35.1 ± 15.6 years; body mass index: 27.7 ± 6.9 kg/m2, 17 with normal and 34 with impaired glucose tolerance) completed two meal tests. The area under the curve (p < 0.001) and incremental area under the curve (p = 0.001) for insulin was significantly higher after the red meat/refined grain diet than after the dairy/chicken/nuts/whole grain diet. There was an interaction between meal and glucose tolerance group (p < 0.05) in the area under the curve (AUC) and the incremental area under the curve (iAUC) of glucose; the red meat/refined grain diet increased glucose relative to the dairy/chicken/nuts/whole grain diet only in the normal group (+2.5 mmol/L/3 h). The red meat/refined grain diet increased glucose and insulin responses compared with the dairy/chicken/nuts/whole grain diet. This meal pattern would increase pancreatic stress long term and may account for the increased risk of type 2 diabetes with this diet.
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Branched-Chain Amino Acids and Insulin Metabolism: The Insulin Resistance Atherosclerosis Study (IRAS). Diabetes Care 2016; 39:582-8. [PMID: 26895884 PMCID: PMC4806771 DOI: 10.2337/dc15-2284] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 01/30/2016] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Recent studies using untargeted metabolomics approaches have suggested that plasma branched-chain amino acids (BCAAs) are associated with incident diabetes. However, little is known about the role of plasma BCAAs in metabolic abnormalities underlying diabetes and whether these relationships are consistent across ethnic populations at high risk for diabetes. We investigated the associations of BCAAs with insulin sensitivity (SI), acute insulin response (AIR), and metabolic clearance of insulin (MCRI) in a multiethnic cohort. RESEARCH DESIGN AND METHODS In 685 participants without diabetes of the Insulin Resistance Atherosclerosis Study (IRAS) (290 Caucasians, 165 African Americans, and 230 Hispanics), we measured plasma BCAAs (sum of valine, leucine, and isoleucine) by mass spectrometry and SI, AIR, and MCRI by frequently sampled intravenous glucose tolerance tests. RESULTS Elevated plasma BCAAs were inversely associated with SI and MCRI and positively associated with fasting insulin in regression models adjusted for potential confounders (β = -0.0012 [95% CI -0.0018, -0.00059], P < 0.001 for SI; β = -0.0013 [95% CI -0.0018, -0.00082], P < 0.001 for MCRI; and β = 0.0015 [95% CI 0.0008, 0.0023], P < 0.001 for fasting insulin). The association of BCAA with SI was significantly modified by ethnicity, with the association only being significant in Caucasians and Hispanics. Elevated plasma BCAAs were associated with incident diabetes in Caucasians and Hispanics (multivariable-adjusted odds ratio per 1-SD increase in plasma BCAAs: 1.67 [95% CI 1.21, 2.29], P = 0.002) but not in African Americans. Plasma BCAAs were not associated with SI-adjusted AIR. CONCLUSIONS Plasma BCAAs are associated with incident diabetes and underlying metabolic abnormalities, although the associations were generally stronger in Caucasians and Hispanics.
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Reduction in peripheral vascular resistance predicts improvement in insulin clearance following weight loss. Cardiovasc Diabetol 2015; 14:113. [PMID: 26297500 PMCID: PMC4546319 DOI: 10.1186/s12933-015-0276-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 08/09/2015] [Indexed: 02/07/2023] Open
Abstract
Background The hyperinsulinemia of obesity is a function of both increased pancreatic insulin secretion and decreased insulin clearance, and contributes to cardiovascular risk. Whilst weight loss is known to enhance insulin clearance, there is a paucity of data concerning the underlying mechanisms. This study was conducted to examine the inter-relationships between changes in sympathetic nervous system (SNS) activity, vascular function and insulin clearance during a weight loss program. Methods Seventeen non-smoking, un-medicated individuals aged 55 ± 1 years (mean ± SEM), body mass index (BMI) 33.9 ± 1.7 kg/m2, underwent a 4-month hypocaloric diet (HCD), using a modified Dietary Approaches to Stop Hypertension diet, whilst seventeen age- and BMI-matched subjects acted as controls. Insulin sensitivity and insulin clearance were assessed via euglycemic hyperinsulinemic clamp (exogenous insulin clearance); hepatic insulin extraction was calculated as fasting C-peptide to insulin ratio (endogenous insulin clearance); SNS activity was quantified by microneurographic nerve recordings of muscle sympathetic nerve activity (MSNA) and whole-body norepinephrine kinetics; and vascular function by calf venous occlusion plethysmography and finger arterial tonometry. Results Weight loss averaged −8.3 ± 0.6 % of body weight in the HCD group and was accompanied by increased clamp-derived glucose utilization (by 20 ± 9 %, P = 0.04) and exogenous insulin clearance (by 12 ± 5 %, P = 0.02). Hepatic insulin extraction increased from 6.3 ± 0.8 to 7.1 ± 0.9 (P = 0.09). Arterial norepinephrine concentration decreased by −12 ± 5 %, whole-body norepinephrine spillover rate by −14 ± 8 %, and MSNA by −9 ± 5 bursts per 100 heartbeats in the HCD group (P all >0.05 versus control group). Step-wise regression analysis revealed a bidirectional relationship between enhanced exogenous insulin clearance post weight loss and reduction in calf vascular resistance (r = −0.63, P = 0.01) which explained 40 % of the variance. Increase in hepatic insulin extraction was predicted by enhanced finger reactive hyperaemic response (P = 0.006) and improvement in oral glucose tolerance (P = 0.002) which together explained 64 % of the variance. Conclusions Insulin clearance is independently and reciprocally associated with changes in vascular function during weight loss intervention. Trial registration ClinicalTrials.gov: NCT01771042 and NCT00408850
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Abstract
Obesity and being overweight are linked with a cluster of metabolic and vascular disorders that have been termed the metabolic syndrome. This syndrome promotes the incidence of cardiovascular diseases that are an important public health problem because they represent a major cause of death worldwide. Whereas there is not a universally-accepted set of diagnostic criteria, most expert groups agree that this syndrome is defined by an endothelial dysfunction, an impaired insulin sensitivity and hyperglycemia, dyslipidemia, abdominal obesity and hypertension. Epidemiological studies suggest that the beneficial cardiovascular health effects of diets rich in green tea are, in part, mediated by their flavonoid content, with particular benefits provided by members of this family such as epigallocatechin gallate (EGCG). Although their bioavailability is discussed, various studies suggest that EGCG modulates cellular and molecular mechanisms of various symptoms leading to metabolic syndrome. Therefore, according to in vitro and in vivo model data, this review attempts to increase our understanding about the beneficial properties of EGCG to prevent metabolic syndrome.
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Vegetarian diets and cardiovascular risk factors in black members of the Adventist Health Study-2. Public Health Nutr 2014; 18:537-45. [PMID: 24636393 DOI: 10.1017/s1368980014000263] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE To compare cardiovascular risk factors between vegetarians and non-vegetarians in black individuals living in the USA. DESIGN A cross-sectional analysis of a sub-set of 592 black women and men enrolled in the Adventist Health Study-2 (AHS-2) cohort of Seventh-day Adventists. SETTING Members of the AHS-2 cohort, who lived in all states of the USA and provinces of Canada. SUBJECTS Black/African-American members of two sub-studies of AHS-2 where blood and physiological measurements were obtained. RESULTS Of these women and men, 25% were either vegan or lacto-ovo-vegetarians (labelled 'vegetarian/vegans'), 13% were pesco-vegetarian and 62% were non-vegetarian. Compared with non-vegetarians, the vegetarian/vegans had odds ratios for hypertension, diabetes, high blood total cholesterol and high blood LDL-cholesterol of 0·56 (95% CI 0·36, 0·87), 0·48 (95% CI 0·24, 0·98), 0·42 (95% CI 0·27, 0·65) and 0·54 (95% CI 0·33, 0·89), respectively, when adjusted for age, gender, education, physical activity and sub-study. Corresponding odds ratios for obesity in vegetarian/vegans and pesco-vegetarians, compared with non-vegetarians, were 0·43 (95% CI 0·28, 0·67) and 0·47 (95% CI 0·27, 0·81), respectively; and for abdominal obesity 0·54 (95% CI 0·36, 0·82) and 0·50 (95% CI 0·29, 0·84), respectively. Results for pesco-vegetarians did not differ significantly from those of non-vegetarians for other variables. Further adjustment for BMI suggested that BMI acts as an intermediary variable between diet and both hypertension and diabetes. CONCLUSIONS As with non-blacks, these results suggest that there are sizeable advantages to a vegetarian diet in black individuals also, although a cross-sectional analysis cannot conclusively establish cause.
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Gender differences in the association of insulin resistance and high-sensitivity c-reactive protein in obese adolescents. J Diabetes Metab Disord 2014; 13:35. [PMID: 24555754 PMCID: PMC3974110 DOI: 10.1186/2251-6581-13-35] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 12/21/2013] [Indexed: 11/23/2022]
Abstract
Background Low-grade vascular inflammation is believed to initiate early atherosclerotic process by inducing insulin resistance (IR), with significant gender differences in adults. We evaluated the relationship between surrogate measures of inflammation and IR in obese adolescents. Methods The association among markers of inflammation [high-sensitivity c-reactive protein (hs-CRP)] and IR, cardiometabolic risk factors and body composition was retrospectively examined in 199 obese adolescents [(111 F/88 M), aged 15.5 ± 1.2 years]. Insulin resistance was assessed using homeostatic model assessment for insulin resistance (HOMA-IR). Results Males had higher body mass index SD-score (BMI-SDS), fat mass (FM), glucose, insulin, HOMA-IR, HbA1c, hs-CRP, triglycerides: HDL-C (TG:HDL-C) ratio than females (p < 0.05), whereas females had higher c-peptide: insulin ratio than males (p < 0.05). Also, 50.8% of subjects were identified with metabolic syndrome with similar gender distribution (M: 57.9% vs. F: 45.1%, p = 0.32). Hs-CRP was correlated with HOMA-IR in the cohort, even when controlling for FM (r = 0.26; p < 0.0001). However, hs-CRP and HOMA-IR displayed a significant correlation only in females (r = 0.37; p < 0.0001) when adjusting for FM and pubertal status. Also, c-peptide: insulin ratio was inversely correlated with hs-CRP (r = −0.32; p < 0.001) and HOMA-IR (r = −0.62; p < 0.0001) and partially mediated the relationship between these biomarkers only among females (β = 0.36, p < 0.001 to β = 0.18, p < 0.05; Sobel Test: p < 0.01). Conclusions A positive association between hs-CRP and HOMA-IR was observed only in adolescent girls which was influenced by altered hepatic insulin clearance. This implies that obese adolescent girls may be at greatest risk of developing early atherosclerosis and diabetes.
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