Characteristics of glucose metabolism in Nordic and South Asian subjects with type 2 diabetes

Insulin and body mass index decrease serum soluble leptin receptor levels in humans

PURPOSE

Test how serum soluble leptin receptor (sOb-R) is influenced by glucose, insulin, body fat, body mass index (BMI), food intake and physical activity.

METHODS

We performed an epidemiological triangulation combining cross-sectional, interventional and Mendelian randomization study designs. In five independent clinical studies (n = 24-823), sOb-R was quantified in serum or plasma by commercial ELISA kits using monoclonal antibodies. We performed mixed models regression and two-sample Mendelian randomization.

RESULTS

In pooled, cross-sectional data, levelling on study, sOb-R associated inversely with body mass index (BMI) (beta [95% CI] -0.19 [-0.21 to -0.17]), body fat (-0.12 [-0.14 to -0.10) and fasting C-peptide (-2.04 [-2.46 to -1.62]). sOb-R decreased in response to acute hyperinsulinaemia during euglycaemic glucose clamp in two independent clinical studies (-0.5 [-0.7 to -0.4] and -0.5 [-0.6 to -0.3]), and immediately increased in response to intensive exercise (0.18 [0.04 to 0.31]) and food intake (0.20 [0.06 to 0.34]). In two-sample Mendelian randomization, higher fasting insulin and higher BMI were causally linked to lower sOb-R levels (inverse variance weighted, -1.72 [-2.86 to -0.58], and -0.20 [-0.36 to -0.04], respectively). The relationship between hyperglycaemia and sOb-R were inconsistent in cross-sectional studies, non-significant in intervention studies, and two-sample Mendelian randomization suggested no causal effect of fasting glucose on sOb-R.

MAIN CONCLUSION

Both BMI and insulin causally decreased serum sOb-R levels. Conversely, intensive exercise and food intake acutely increased sOb-R. Our results suggest that sOb-R is involved in short-term regulation of leptin signalling, either directly or indirectly, and that hyperinsulinaemia may reduce leptin signalling.

Fetuin-A mediates the difference in adipose tissue insulin resistance between young adult pakistani and norwegian patients with type 2 diabetes

BACKGROUND

South-Asian immigrants to Western countries have a high prevalence of type 2 diabetes mellitus (T2DM) and increased adipose tissue insulin resistance (AT-IR), as compared to their Western counterparts. Fetuin-A is a hepatokine known to influence AT-IR.

AIM

Can plasma fetuin-A concentrations explain an ethnic difference in adipose tissue insulin resistance?

METHODS

We performed a two-step euglycemic-hyperinsulinaemic clamp and measured plasma concentrations of fetuin-A and non-esterified fatty acids (NEFA), in 18 Pakistani and 21 Norwegians with T2DM (age 29-45y) in Norway. AT-IR was calculated as NEFA-suppression during the clamp. The adipokines/cytokines leptin, adiponectin, visfatin, PTX3, IL-1β, INF-γ, and IL-4 were measured in fasting plasma. Liver fat was estimated by CT-scans.

RESULTS

Despite a lower BMI, Pakistani patients displayed higher AT-IR than Norwegians. NEFA-suppression during clamp was lower in Pakistani than Norwegians (mean=-20.6%, 95%CI=[-40.8, -0.01] and p = 0.046). Plasma fetuin-A concentration was higher in Pakistani than Norwegians (43.4 ng/mL[12.7,74.0], p = 0.007) and correlated negatively to %NEFA-suppression during clamp (rho=-0.39, p = 0.039). Plasma fetuin-A concentration explained 22% of the ethnic difference in NEFA-suppression during the clamp. Pakistani patients exhibited higher plasma leptin and lower PTX3 levels than Norwegian, and plasma visfatin correlated positively to plasma fetuin-A levels in the Pakistani patients. We observed no correlation between plasma fetuin-A and liver fat, but fetuin-A correlated negatively with plasma IL-1β, INF-γ, and IL-4 concentrations. Plasma IL-4 concentration was lower in Pakistani than in Norwegian patients.

CONCLUSION

Fetuin-A may contribute to explain the discrepancy in T2DM prevalence between Pakistani and Norwegians patients by influencing AT-IR.

Ethnic disparities attributed to the manifestation in and response to type 2 diabetes: insights from metabolomics

Type 2 diabetes (T2D) associated health disparities among different ethnicities have long been known. Ethnic variations also exist in T2D related comorbidities including insulin resistance, vascular complications and drug response. Genetic heterogeneity, dietary patterns, nutrient metabolism and gut microbiome composition attribute to ethnic disparities in both manifestation and progression of T2D. These factors differentially regulate the rate of metabolism and metabolic health. Metabolomics studies have indicated significant differences in carbohydrate, lipid and amino acid metabolism among ethnicities. Interestingly, genetic variations regulating lipid and amino acid metabolism might also contribute to inter-ethnic differences in T2D. Comprehensive and comparative metabolomics analysis between ethnicities might help to design personalized dietary regimen and newer therapeutic strategies. In the present review, we explore population based metabolomics data to identify inter-ethnic differences in metabolites and discuss how (a) genetic variations, (b) dietary patterns and (c) microbiome composition may attribute for such differences in T2D.

Twenty-Year Trajectory-Patterns of Percentage Energy From Dietary Fat vs. Carbohydrate Throughout Adult Life and Associations With Cardio-Metabolic Disease and All-Cause Mortality

Background: The health impacts of dietary fat-to-energy ratio (FER) compared to carbohydrate-to-energy ratio (CER) are widely discussed topics in public health. This study aimed to assess the health impacts of FER and CER by establishing trajectory-patterns of FER and CER over the course of adult life. Methods: This study used the weighted longitudinal data of the China Health and Nutrition Survey, including eight surveys from 1991 to 2011. The trajectories of FER and CER were determined via latent class trajectory modeling. The trajectories were then cross-grouped into different trajectory-patterns. Multivariate Cox regression models were used to assess the relationship between these trajectory-patterns and cardio-metabolic diseases and all-cause mortality. Ten thousand nine hundred and twenty-six adults with a total of 50,693 observations across eight surveys were included. Results: Compared to the trajectory-pattern of persistently low-FER (increased from 10 to 20%) and moderate-CER (stable and ranging from 55 to 65%) over the adult life-course, the two trajectory-patterns that showed changing to high-FER and low-CER were significantly associated with obesity [HR 1.83 [95% CI, 1.10-3.04]; HR 1.46 [95% CI, 1.02-2.17]], diabetes [HR 1.80 [95% CI, 1.03-3.16]; HR 1.49 [95% CI, 1.01-2.25]], and all-cause mortality [HR 2.29 [95% CI, 1.35-3.87]; HR 1.62 [95% CI, 1.18-2.22]]. In contrast, the trajectory-pattern of a persistently low-FER and high-CER diet was not associated with obesity [HR 1.19 [95% CI, 0.82-1.17]], diabetes [HR 1.41 [95% CI, 0.98-2.02]], cardiovascular-disease [HR 1.48 [95% CI, 0.91-2.39]], and all-cause mortality [HR 1.23 [95% CI, 0.94-1.61]]. Conclusions: This study indicates that changing to a high-FER and low-CER diet over the course of adult life was significantly associated with obesity, diabetes, and all-cause mortality in the Chinese adult population. In addition, low-FER and high-CER were not associated with cardio-metabolic disease and all-cause mortality. These observations may provide insights into nutritional policy and dietary guidelines.

Vitamin D deficiency in western dwelling South Asian populations: an unrecognised epidemic

Vitamin D deficiency (25-hydroxyvitamin D; 25(OH)D) is at epidemic proportions in western dwelling South Asian populations, including severe deficiency (<12⋅5 nmol/l) in 27-60% of individuals, depending on season. The paper aimed to review the literature concerning vitamin D concentrations in this population group. Research from the UK and Europe suggests a high prevalence of South Asians with 25(OH)D concentration <25 nmol/l, with most having a 25(OH)D concentration of <50 nmol/l. In Canada, South Asians appear to have a slightly higher 25(OH)D concentration. There are few studies from the United States, South Africa and Australasia. Reasons for vitamin D deficiency include low vitamin D intake, relatively high adiposity, sun exposure avoidance and wearing of a covered dress style for cultural reasons. Possible health effects of deficiency include bone diseases such as rickets and hypocalcaemia in children and osteomalacia in adults. Vitamin D deficiency may also increase the risk of other chronic diseases. Increased fortification of food items relevant to South Asian groups (e.g. chapatti flour), as well as increased use of vitamin D supplements may help reduce this epidemic. Introducing culturally acceptable ways of increasing skin exposure to the sun in South Asian women may also be beneficial but further research is needed to assess the effectiveness of different approaches. There may be a need for a South Asian specific vitamin D dietary intake guideline in western countries. To conclude, vitamin D deficiency is epidemic in South Asians living in western countries and there is a clear need for urgent public health action.

Substantial inter-individual variations in insulin secretion and sensitivity across the glucometabolic spectrum

Impaired insulin secretion and action are important for development of type 2 diabetes (T2D) and metabolic syndrome (MetS). Despite recognized heterogeneity of these glucometabolic disorders, few data are available of biological variation in insulin secretion and action among individuals with T2D and MetS. The aim of this study was to explore the inter-individual variations using gold standard methods in a cross-sectional study of two independent cohorts of phenotypically well-characterized subjects. Cohort I included 486 subjects with MetS, and cohort II 62 subjects with established T2D. First phase insulin secretion was defined as the incremental area under the curve 0-8 min (iAUC_0-8 min) during an intravenous glucose tolerance test (IVGTT). Insulin sensitivity was measured as the insulin sensitivity index (S_I) modelled from IVGTT in cohort I, and in II as total glucose disposal (TGD) estimated from a euglycaemic-hyperinsulinaemic clamp. Variation is given as total range and, fold-variation between 5%- and 95%-percentile. The iAUC_0-8 min ranged from -60 to 3397 mUL^-1min^-1 among subjects with MetS and from -263 to 1194 mUL^-1min^-1 in subjects with T2D, representing a more than 10-fold variation. Insulin sensitivity ranged from S_I 0.19 to 15.29 (mU/L)^-1min^-1 among subjects with MetS and TGD 12.9-101.6 μmolkgFFM^-1min^-1 in subjects with T2D, representing a 6.8 and 5.5-fold variation, respectively. The other components of MetS; BMI, waist-hip ratio, HDL-cholesterol, triglycerides and blood pressure (BP), showed a 1.4-4.7-fold variation. In conclusion, our data demonstrated extensive inter-individual variations in insulin secretion and sensitivity. These variations may be essential to take into account when planning clinical research and treatment in subjects with T2D and MetS.

The relationship of acculturation to cardiovascular disease risk factors among U.S. South Asians: Findings from the MASALA study

AIM

We investigated the association between acculturation strategies and cardiometabolic risk among South Asian (SA) immigrants in the US.

METHODS

In this cross-sectional analysis of data from 849 SA participants in the Mediators of Atherosclerosis in SAs Living in America (MASALA), we performed multidimensional measures of acculturation to categorize the participants into three acculturation classes: separation (preference for SA culture), assimilation (preference for US culture), and integration (similar preference for both cultures). Differences in glycemic indices, blood pressure, lipid parameters and body composition by acculturation strategy were examined.

RESULTS

Women in the integration class had the lowest prevalence of diabetes (16.4%), prediabetes (29.7%), fasting and 2-h glucose compared to women in the separation class with the highest prevalence of diabetes (29.3%), prediabetes (31.5%), fasting and 2-h glucose and 2-hr insulin (all p < 0.05). Women in the assimilation class had significantly lower triglycerides, BMI, and waist circumference and higher HDL compared to women in the separation class after adjusting for age, study site, and years in the US. After additionally accounting for socioeconomic/lifestyle factors, women in the assimilation class had significantly lower triglyceride and higher HDL levels compared to women in the separation class (p < 0.01). There was no significant association between acculturation strategies and cardiometabolic risk in SA men.

CONCLUSION

SA women who employed an assimilation or integration strategy had a more favorable cardiometabolic profile compared to women using a separation strategy. Future research should investigate the behavioral and psychosocial pathways linking acculturation strategies with cardiometabolic health to inform preventive interventions among SAs living in America.

Vitamin D supplementation improves waist-to-hip ratio and fasting blood glucose in vitamin D deficient, overweight or obese Asians: A pilot secondary analysis of a randomised controlled trial

Recent trials do not support a role for vitamin D supplementation in prevention or treatment of type 2 diabetes mellitus, although effects may differ in Asian populations. In this pilot secondary analysis of a placebo-controlled randomised trial of overweight or obese individuals with low 25-hydroxyvitamin D (25(OH)D < 50 nmol/L), we examined whether vitamin D supplementation improved insulin sensitivity or body composition in participants of Asian ethnicity. Amongst 65 trial participants, 33 reported being of Asian descent (mean ± SD age 30 ± 7 years; 67% male). Participants were block randomised to receive vitamin D (n = 14; initial bolus dose of 2500 μg cholecalciferol followed by 100 μg cholecalciferol/d) or placebo (n = 19; identical capsules) for 16 weeks. Primary outcome was change in insulin sensitivity (M-value) assessed by hyperinsulinemic-euglycemic clamp. Secondary outcomes were changes in 25(OH)D (chemiluminescent immunoassay), fasting blood glucose (YSI Stat 2300), and body composition including waist-hip ratio and total body fat percentage (dual-energy X-ray absorptiometry). Questionnaires assessed sun-exposure habits, physical activity, and diet. After the 16-week intervention, 25(OH)D concentrations increased significantly in the vitamin D group with no change in placebo (61.4 ± 21.1 vs -0.4 ± 12.7 nmol/L; P < 0.01). Vitamin D group participants demonstrated significant improvements in waist-hip ratio (-0.02 ± 0.03 vs 0.00 ± 0.02; P < 0.01) and fasting blood glucose (-0.1 ± 0.2 vs 0.2 ± 04 mmol/L; P < 0.04) compared with the placebo group, but changes in insulin sensitivity and other body composition measures did not differ significantly between groups (all P > 0.05). In conclusion, vitamin D supplementation improved waist-hip ratio and fasting blood glucose in overweight and obese Asian-Australians with low vitamin D concentrations. Further research is required to determine whether vitamin D supplementation is potentially more effective in specific ethnic groups.

An adapted isotope dilution 1H-13C heteronuclear single-quantum correlation (ID-HSQC) for rapid and accurate quantification of endogenous and exogenous plasma glucose

A wide variety of methods, such as enzymatic methods, LC-MS, and LC-MS/MS, are currently available for the concentration determination of plasma glucose in studies of diabetes, obesity, exercise, etc. However, these methods rarely discriminate endogenous and exogenous glucose in plasma. A novel NMR strategy for discriminative quantification of the endogenous and exogenous glucose in plasma has been developed using an adapted isotope dilution ¹H-¹³C heteronuclear single-quantum correlation (ID-HSQC) with uniformly ¹³C-labeled glucose as a tracer of exogenous glucose. This method takes advantage of the distinct ¹H-¹³C chemical shifts of the hemiacetal group of the α-D-glucopyranose and makes use of the ¹³C-¹³C one-bond J-coupling (¹J_CC) in uniformly ¹³C-labeled glucose to differentiate the ¹H-¹³C HSQC signal of labeled glucose from that of its natural counterpart when data are acquired in high-resolution mode. The molar ratio between the endogenous and exogenous plasma glucose can then be calculated from the peak intensities of the natural and labeled glucose. The accuracy and precision of the method were evaluated using a series of standard mixtures of natural and uniformly ¹³C-labeled glucose with varied but known concentrations. Application of this method is demonstrated for the quantification of endogenous and exogenous glucose in plasma derived from healthy and diabetic cynomolgus monkeys. The results nicely agree with our previous LC-MS/MS results. Considering the natural abundance of ¹³C isotope at the level of 1.1% in endogenous glucose, comparable peak intensities of quantitatively measurable signals derived from natural and labeled glucose imply that the ID-HSQC can tolerate a significantly high ratio of isotope dilution, with labeled/natural glucose at ~ 1%. We expect that the ID-HSQC method can serve as an alternative approach to the biomedical or clinical studies of glucose metabolism.

Comprehensive assessment of insulin resistance in non-obese Asian Indian and Chinese men

Aims/Introduction

Indian individuals are more insulin resistant (IR) than Chinese individuals, even among those with a non‐obese body mass index (BMI). However, BMI often underestimates body fat in Indian individuals, and it remains unclear whether Indians would remain more IR than Chinese individuals when both BMI and body fat are equally matched.

Materials and Methods

Using the hyperinsulinemic‐euglycemic clamp with stable‐isotope infusion, we comprehensively assessed IR between 13 non‐obese Indian men with 13 Chinese men matched for age, BMI and body fat. We further compared the differences in insulin metabolic clearance rate (MCR) between the two groups and its relationship with various metabolic parameters. The response of lipid and amino acid metabolism to insulin stimulation was also evaluated using metabolomic profiling.

Results

The rates of endogenous glucose production during fasting were similar, and endogenous glucose production was completely suppressed during insulin clamp for both ethnic groups. Glucose disappearance during insulin clamp was also similar between the two groups, even after accounting for differences in insulin concentration. Metabolomic profiles of amino acids and various acylcarnitines were similar during both fasting and insulin clamp. However, plasma insulin during clamp was significantly higher in Indian men, indicating that insulin MCR was lower. Insulin MCR correlated significantly with total adiposity and skeletal muscle insulin sensitivity.

Conclusion

When equally matched for body fat, non‐obese Indian men had similar skeletal muscle insulin sensitivity and endogenous glucose production to Chinese men. The effects of insulin on lipid and amino acid metabolism were also similar. Low insulin MCR is associated with greater adiposity and lower skeletal muscle insulin sensitivity.

Effects of Vitamin D Supplementation on Insulin Sensitivity and Insulin Secretion in Subjects With Type 2 Diabetes and Vitamin D Deficiency: A Randomized Controlled Trial

OBJECTIVE

In observational studies, low vitamin D levels are associated with type 2 diabetes (T2D), impaired glucose metabolism, insulin sensitivity, and insulin secretion. We evaluated the efficacy of vitamin D supplementation on insulin sensitivity and insulin secretion in subjects with T2D and low vitamin D (25-hydroxyvitamin D [25(OH)D] <50 nmol/L).

RESEARCH DESIGN AND METHODS

Sixty-two men and women with T2D and vitamin D deficiency participated in a 6-month randomized, double-blind, placebo-controlled trial. Participants received a single dose of 400,000 IU oral vitamin D₃ or placebo, and the vitamin D group received an additional 200,000 IU D₃ if serum 25(OH)D was <100 nmol/L after 4 weeks. Primary end points were total R_d by euglycemic clamp with assessment of endogenous glucose production and first-phase insulin secretion by intravenous glucose tolerance test.

RESULTS

In the vitamin D group, the mean ± SD baseline serum 25(OH)D of 38.0 ± 12.6 nmol/L increased to 96.9 ± 18.3 nmol/L after 4 weeks, 73.2 ± 13.7 nmol/L after 3 months, and 53.7 ± 9.2 nmol/L after 6 months. The total exposure to 25(OH)D during 6 months (area under the curve) was 1,870 ± 192 and 1,090 ± 377 nmol/L per week in the vitamin D and placebo groups, respectively (P < 0.001). Insulin sensitivity, endogenous glucose production, and glycemic control did not differ between or within groups after treatment (P = 0.52). First-phase insulin secretion did not change significantly after treatment (P = 0.10).

CONCLUSIONS

Replenishment with a large dose of vitamin D₃ to patients with T2D and vitamin D deficiency did not change insulin sensitivity or insulin secretion. These findings do not support such use of therapeutic vitamin D₃ supplementation to improve glucose homeostasis in patients with T2D.

Special considerations for vitamin D in the south Asian population in the UK

The human requirement for vitamin D is achieved primarily through the synthesis of this prehormone in the skin during exposure to ultraviolet B (UVB) radiation, with only a minor contribution from the diet, year round. Achieving optimal vitamin D status is therefore largely dependent upon adequate exposure of the skin to sunlight, however, the length of exposure required varies with latitude and season, and is also dependent upon skin pigmentation, with darker skin requiring greater exposure than fair skin due to the protective effects of melanin against UVB radiation. In northern European latitudes, where UVB radiation between the months of October and March is of insufficient intensity for the synthesis of vitamin D via this route, vitamin D deficiency is a public health concern, particularly for south Asian diaspora and other dark-skinned ethnic minority communities. The consequences of vitamin D deficiency include poor bone health, including rickets and osteomalacia. In addition, there is increasing awareness of an important role for vitamin D in the development and progression of chronic diseases, including type 2 diabetes, which is prevalent in south Asian populations. The aim of this review is to examine some of the most recent reports of vitamin D status in south Asian diaspora communities, and to explore its impact on bone health. In addition, we will examine the putative association between type 2 diabetes and vitamin D deficiency in south Asian populations and the current guidelines for treatment of vitamin D deficiency of south Asians in primary care settings.

Cardiometabolic disease in South Asians: A global health concern in an expanding population

Cardiovascular disease (CVD) is one of the main causes of mortality and morbidity worldwide. As an emerging population, South Asians (SAs) bear a disproportionately high burden of CVD relative to underlying classical risk factors, partly attributable to a greater prevalence of insulin resistance and diabetes and distinct genetic and epigenetic influences. While the phenotypic distinctions between SAs and other ethnicities in CVD risk are becoming increasingly clear, the biology of these conditions remains an area of active investigation, with emerging studies involving metabolism, genetic variation and epigenetic modifiers (e.g., extracellular RNA). In this review, we describe the current literature on prevalence, prognosis and CVD risk in SAs, and provide a landscape of translational research in this field toward ameliorating CVD risk in SAs.

LIGHT/TNFSF14 is increased in patients with type 2 diabetes mellitus and promotes islet cell dysfunction and endothelial cell inflammation in vitro

AIMS/HYPOTHESIS

Activation of inflammatory pathways is involved in the pathogenesis of type 2 diabetes mellitus. On the basis of its role in vascular inflammation and in metabolic disorders, we hypothesised that the TNF superfamily (TNFSF) member 14 (LIGHT/TNFSF14) could be involved in the pathogenesis of type 2 diabetes mellitus.

METHODS

Plasma levels of LIGHT were measured in two cohorts of type 2 diabetes mellitus patients (191 Italian and 40 Norwegian). Human pancreatic islet cells and arterial endothelial cells were used to explore regulation and relevant effects of LIGHT in vitro.

RESULTS

Our major findings were: (1) in both diabetic cohorts, plasma levels of LIGHT were significantly raised compared with sex- and age-matched healthy controls (n = 32); (2) enhanced release from activated platelets seems to be an important contributor to the raised LIGHT levels in type 2 diabetes mellitus; (3) in human pancreatic islet cells, inflammatory cytokines increased the release of LIGHT and upregulated mRNA and protein levels of the LIGHT receptors lymphotoxin β receptor (LTβR) and TNF receptor superfamily member 14 (HVEM/TNFRSF14); (4) in these cells, LIGHT attenuated the insulin release in response to high glucose at least partly via pro-apoptotic effects; and (5) in human arterial endothelial cells, glucose boosted inflammatory response to LIGHT, accompanied by an upregulation of mRNA levels of HVEM (also known as TNFRSF14) and LTβR (also known as LTBR).

CONCLUSIONS/INTERPRETATION

Our findings show that patients with type 2 diabetes mellitus are characterised by increased plasma LIGHT levels. Our in vitro findings suggest that LIGHT may contribute to the progression of type 2 diabetes mellitus by attenuating insulin secretion in pancreatic islet cells and by contributing to vascular inflammation.

A 70% Ethanol Extract of Mistletoe Rich in Betulin, Betulinic Acid, and Oleanolic Acid Potentiated β-Cell Function and Mass and Enhanced Hepatic Insulin Sensitivity

We investigated that the long-term consumption of the water (KME-W) and 70% ethanol (KME-E) mistletoe extracts had antidiabetic activities in partial pancreatectomized (Px) rats. Px rats were provided with a high-fat diet containing 0.6% KME-E, 0.6% KME-W, and 0.6% dextrin (control) for 8 weeks. As normal-control, Sham-operated rats were provided with 0.6% dextrin. In cell-based studies, the effects of its main terpenoids (betulin, betulinic acid, and oleanolic acid) on glucose metabolism were measured. Both KME-W and KME-E decreased epididymal fat mass by increasing fat oxidation in diabetic rats. KME-E but not KME-W exhibited greater potentiation of first-phase insulin secretion than the Px-control in a hyperglycemic clamp. KME-E also made β-cell mass greater than the control by increasing β-cell proliferation and decreasing its apoptosis. In a euglycemic-hyperinsulinemic clamp, whole-body glucose infusion rate and hepatic glucose output increased with potentiating hepatic insulin signaling in the following order: Px-control, KME-W, KME-E, and normal-control. Betulin potentiated insulin-stimulated glucose uptake via increased PPAR-γ activity and insulin signaling in 3T3-L1 adipocytes, whereas oleanolic acid enhanced glucose-stimulated insulin secretion and cell proliferation in insulinoma cells. In conclusion, KME-E prevented the deterioration of glucose metabolism in diabetic rats more effectively than KME-W and KME-E can be a better therapeutic agent for type 2 diabetes than KME-W.

Cardiovascular Disease in South Asian Migrants

Cardiovascular disease (CVD) represents a significant cause of global mortality and morbidity. South Asians (SAs) have a particularly high burden of coronary artery disease (CAD). This review describes current literature regarding the prevalence, incidence, etiology, and prognosis of CVD in SA migrants to high-income nations. We conducted a narrative review of CVD in the SA diaspora through a search of MEDLINE and PubMed. We included observational studies, randomized clinical trials, nonsystematic reviews, systematic reviews, and meta-analyses written in English. Of 15,231 articles identified, 827 articles were screened and 124 formed the basis for review. SA migrants have a 1.5-2 times greater prevalence of CAD than age- and sex-adjusted Europids. Increased abdominal obesity and body fat and increased burden of type 2 diabetes mellitus and dyslipidemia appear to be primary drivers of the excess CAD burden in SAs. Sedentary lifestyle and changes in diet after immigration are important contributors to weight gain and adiposity. Early life factors, physical activity patterns and, in some cases, reduced adherence to medical therapy may contribute to increased CVD risks in SAs. Novel biomarkers like leptin and adipokines may show distinct patterns in SAs and provide insights into cardiometabolic risk determinants. In conclusion, SAs have distinct CVD risk predispositions, with a complex relationship to cultural, innate, and acquired factors. Although CVD risk factor management and treatment among SAs is improving, opportunities exist for further advances.