Body mass index and triglyceride-to-HDL-cholesterol ratio in relation to risk of diabetes: The Nagasaki Islands study

Body mass index (BMI) is well known as an independent risk factor for insulin resistance. In addition, lower BMI and lower insulin levels are recognized as specific characteristics of Asian diabetes patients. Since the triglyceride-to-HDL-cholesterol ratio (TG-HDL) is positively associated with insulin level, but inversely associated with insulin sensitivity, we supposed that diabetes combined with high but not with low TG-HDL might be positively associated with BMI. We therefore conducted a cross-sectional study of 2,431 Japanese subjects (905 men and 1,526 women) aged 30-79 years, who underwent a general health check, to investigate associations between BMI, diabetes and its subtypes that we defined on the basis of TG-HDL levels, which in turn were categorized according to sex-specific tertiles. Among the 172 diabetic patients identified in the study group, 45 showed low TG-HDL and 82 high TG-HDL. We found a significant inverse association between low-TG-HDL diabetes and BMI, and a significant positive association between high-TG-HDL diabetes and BMI. The multivariable-adjusted odds ratio and 95%CI for a 1SD increment in BMI (3.03 kg/m² for men and 3.44 kg/m² for women) for low-TG-HDL diabetes was 0.53 (95%CI: 0.36-0.77) and 1.57 (95%CI: 1.24-2.01) for high-TG-HDL diabetes. These findings demonstrated that for Japanese subjects associations between diabetes and BMI are strongly influenced by the TG-HDL status. Since a previous study of ours found that diabetes combined with high TG-HDL ratios constitutes a risk for atherosclerosis, these findings may serve as an effective tool for estimating risk of atherosclerosis for diabetes patients.