Correlation between serum insulin and features of metabolic syndrome in Thais

Several clinical and metabolic abnormalities, i.e. central obesity, hypertension, impaired glucose tolerance or diabetes and dyslipidemia often cluster together and are commonly found in patients with atherosclerotic cardiovascular disease. Hyperinsulinemia and insulin resistance are often evident in subjects with these metabolic abnormalities, so called insulin resistance or metabolic syndrome. In the present study, we looked into the correlations between serum insulin or index of insulin sensitivity and various clinical and metabolic abnormalities. Subjects consisted of 103 males and 118 females. Oral glucose tolerance test was performed on all subjects. Homeostasis model assessment of insulin sensitivity (HOMA-S) was used to determine insulin sensitivity. In males, HOMA-S was found to be significantly correlated with BMI, plasma glucose, insulin, triglycerides and waist circumference. Male subjects in the highest quartile of HOMA-S also had significantly higher systolic blood pressure compared to those in the lowest quartile. In females, HOMA-S was significantly correlated with BMI, blood pressure, plasma glucose, insulin, triglycerides, HDL-cholesterol, waist circumferences and waist-hip ratio. However, after adjustment for BMI, correlation between HOMA-S and blood pressure in women was no longer statistically significant. We, therefore, concluded that correlations between serum insulin or index of insulin sensitivity with certain metabolic abnormalities also existed in Thai subjects. Some of these correlations seem to be at least in part dependent on obesity.