The association between the ratio of triglyceride to HDL-C and insulin resistance according to waist circumference in a rural Korean population.

BACKGROUND AND AIMS: This study aimed to examine the association between an increased ratio of triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) and insulin resistance as well as to investigate the interactive effect of TG/HDL-C and waist circumference on insulin resistance in a rural Korean population.

METHODS AND RESULTS: This study, employing a cross-sectional design, included 8411 participants from the Korean Genomic Rural Cohort Study. Levels of fasting insulin, lipid profiles and anthropometric data were assessed for all participants. Insulin resistance was defined as a value greater than the 75th percentile on the homeostasis model assessment of insulin resistance (HOMA-IR). The TG/HDL-C ratio was positively correlated with waist circumference, total cholesterol, low-density lipoprotein cholesterol (LDL-C), TG and HOMA-IR, and negatively correlated with HDL-C when the calculations were controlled for gender. In comparison with the lowest quartile group of TG/HDL-C (≤1.92 in men, ≤1.63 in women), the odds ratios (ORs) (95% confidence interval) for insulin resistance in the highest quartile group of TG/HDL-C (>4.90 in men, >3.93 in women) were 2.33 (1.72-3.16) in men and 2.16 (1.73-2.71) in women, after adjusting for multiple covariates including waist circumference. Following stratification of waist circumference into quartiles, the effect of TG/HDL-C on insulin resistance remained significant irrespective of the waist circumference quartile.

CONCLUSION: The TG/HDL-C ratio was linearly associated with insulin resistance in a rural Korean cohort independently of waist circumference in both genders, albeit not interactive.