Serum insulin is significantly related to components of the metabolic syndrome in Japanese working men.

The aim of this study was to examine the association between serum insulin levels and components of the metabolic syndrome (MS). The target participants were 3054 working men. MS was diagnosed based on the modified criteria of the International Diabetes Federation and was present in 12.9% of the study patients. Serum lipid profiles, uric acid, insulin, plasma glucose, and hemoglobin A1c were measured. Stepwise multiple regression analysis showed that all the components of MS were significantly associated with log-transformed values of the serum insulin. The standardized regression coefficient for the waist circumference was 5-fold higher than that for fasting plasma glucose, being 0.40 and 0.08, respectively. The standardized regression coefficients for diastolic blood pressure, log-transformed values of serum triglyceride, high-density lipoprotein cholesterol, and age were 0.09, 0.13, -0.16, and -0.11, respectively. A statistically significant relationship existed between the components of MS, especially abdominal obesity, and the serum insulin levels.