Background

South Asians have increased risk for type-2 diabetes and cardiovascular disease, but the relationship between metabolic health and weight has not been described. This study establishes the prevalence of metabolic abnormalities in normal weight, overweight, and obese South Asians.

Methods

Participants were categorized by body mass index and waist circumference. Subjects with two or more cardiometabolic risk factors (blood pressure, glucose, insulin, triglycerides, high-density lipoprotein cholesterol, and C-reactive protein) were defined as metabolically abnormal.

Results

Forty-one percent of the sample (n=1015) was metabolically abnormal, and 12% of those were normal weight. Of metabolically healthy individuals, 58% were overweight or obese. At a normal level of adiposity, women were more likely to be metabolically unhealthy, whereas men were more likely to be unhealthy with increasing adiposity.

Conclusions

Similar to other ethnic groups, a significant number of normal weight South Asians can be metabolically unhealthy.

Background & objectives

Prevalence of insulin resistance and associated dyslipidaemia [high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) concentrations] are increased in South Asian individuals; likely contributing to their increased risk of type-2 diabetes and cardiovascular disease. The plasma concentration ratio of TG/HDL-C has been proposed as a simple way to identify apparently healthy individuals at high cardio-metabolic risk. This study was carried out to compare the cardio-metabolic risk profiles of high-risk South Asian individuals identified by an elevated TG/HDL-C ratio versus those with a diagnosis of the metabolic syndrome.

Methods

Body mass index, waist circumference, blood pressure, and fasting plasma glucose, insulin, TG, and HDL-C concentrations were determined in apparently healthy men (n=498) and women (n=526). The cardio-metabolic risk profile of "high risk" individuals identified by TG/HDL-C ratios in men (≥ 3.5) and women (≥2.5) was compared to those identified by a diagnosis of the metabolic syndrome.

Results

More concentrations of all cardio-metabolic risk factors were significantly higher in "high risk" groups, identified by either the TG/HDL-C ratio or a diagnosis of the metabolic syndrome. TG, HDL-C, and insulin concentrations were not significantly different in "high risk" groups identified by either criterion, whereas plasma glucose and blood pressure were higher in those with the metabolic syndrome.

Interpretation & conclusions

Apparently healthy South Asian individuals at high cardio-metabolic risk can be identified using either the TG/HDL-C ratio or the metabolic syndrome criteria. The TG/HDL-C ratio may be used as a simple marker to identify such individuals.

Introduction

The aims of this study were to compare microRNA (miR) expression between individuals with and without insulin resistance and to determine whether miRs predict response to thiazolidinedione treatment.

Materials and methods

In a sample of 93 healthy adults, insulin resistance was defined as steady state plasma glucose (SSPG)≥180 mg/dL and insulin sensitive as <120 mg/dL. Response to thiazolidinedione therapy was defined as ≥10% decrease in SSPG. We selected a panel of microRNAs based on prior evidence for a role in insulin or glucose metabolism. Fold change and Wilcoxon rank sum tests were calculated for the 25 miRs measured.

Results

At baseline, 81% (n=75) of participants were insulin resistant. Five miRs were differentially expressed between the insulin resistant and sensitive groups: miR-193b (1.45 fold change (FC)), miR-22-3p (1.15 FC), miR-320a (1.36 FC), miR-375 (0.59 FC), and miR-486 (1.21 FC) (all p<0.05). In the subset who were insulin resistant at baseline and received thiazolidinediones (n=47), 77% (n=36) showed improved insulin sensitivity. Six miRs were differentially expressed between responders compared to non-responders: miR-20b-5p (1.20 FC), miR-21-5p, (0.92 FC), miR-214-3p (1.13 FC), miR-22-3p (1.14 FC), miR-320a (0.98 FC), and miR-486-5p (1.25 FC) (all p<0.05).

Discussion

This study is the first to report miRs associated with response to a pharmacologic intervention for insulin resistance. MiR-320a and miR-486-5p identified responders to thiazolidinedione therapy among the insulin resistant group.