Impact of changes in obesity parameters on glucose metabolism and insulin resistance over a one-year period.

AIM Changes in indexes of obesity, such as waist circumference (WC) and body mass index (BMI), may influence some glucose metabolism-related parameters in both obese and non-obese subjects. We have investigated the impact of changes in WC and in BMI on data related to glucose metabolism over a one-year period. METHODS Data from 3213 individuals (2014 men, 1199 women) who underwent a general health screening two years running and were not taking antidiabetic medication were analyzed. RESULTS In men, percent changes in WC (%dWC) and BMI (%dBMI) were both significantly correlated with percent changes in fasting glucose (%dFG), in hemoglobin A(1C) (%dHbA(1C)), and in HOMA-IR (%dHOMA-IR). In women, these relationships were not significant except for the relationship between %dBMI and %dHOMA-IR. In a multivariate linear regression analysis using age, %dBMI, and %dWC as independent variables, %dBMI, but not %dWC, was found to be an independent predictor of %dHOMA-IR in both genders. Furthermore, in men, %dBMI was also an independent factor predicting %dFG and %dHbA(1C). CONCLUSION During the one-year period, a reduction in BMI, and thus weight loss, was found to be associated with the improvement of insulin sensitivity, especially in men. A reduction in WC was also associated with an improvement in insulin sensitivity in men; however, this relationship did not remain significant after controlling for changes in BMI.