Insulin concentration is the main predictor of leptin level: a homogenous type 2 diabetes cohort study in Taiwan

We hypothesized that there would be strong association between insulin level and leptin level, and attempted to examine factors affecting plasma leptin level among the homogeneous Type 2 diabetes subjects. The study was conducted from July 2005 through September 2005 in the Taipei Hospital, Taiwan. From 1356 registered diabetes patients, 120 subjects who met the criteria of (1) aged between 20 and 75 years, (2) being Chinese, (3) having Type 2 diabetes for more than one year, (4) having been taking gliclazide and metformin for more than 6 months, were enrolled for this study. Factors affecting plasma leptin level are determined using multiple linear regression analysis. The coefficients obtained by multiple regression analysis with stepwise method showed that gender (β=-0.49, p<0.001), insulin level (β=0.46, p<0.001) and body mass index (BMI)(β=0.21, p=0.003) were the main predictors of leptin concentrations for all type 2 diabetic subjects; insulin level (β=0.50, p<0.001), BMI (β=0.42, p<0.001) and triglyceride (β=0.17, p=0.03) were the main predictors for type 2 diabetic men; and insulin level (β=0.68, p<0.001) was the only predictor for type 2 diabetic women. These initial findings seem to indicate that insulin concentration is the main predictor of leptin level in both male and female type 2 diabetes subjects.