ABSTRACT
Excess weight is a well known risk factor for Type 2 diabetes mellitus. Several studies have estimated the population attributable risk of diabetes associated with overweight and obesity in developed countries. However, little evidence exists regarding the contribution of excess weight to diabetes in the Middle East countries. This study aimed at quantification of the impact of overweight and obesity on a population level in Iran. Using data of a population-based short-term cohort study in Iran, which began in 1998 with 3.6-year follow-up, we calculated the adjusted odds ratios [OR] and population attributable risks [PAR] of developing diabetes, i.e. the proportion of diabetes that would have been avoided had overweight and/or obesity not been present in the population. Results: Of the 4728 subjects studied, during the 3.6- year follow-up period, 3.5% [n=164] developed diabetes. This proportion was 1.3%, 3.2%, and 7.0% for the normal, overweight, and obese subjects, respectively. When compared to normal BMI, the adjusted ORs for incident diabetes were 1.78 [95% confidence interval [CI] 1.05 to 3.02] for overweight and 3.61 [95% CI 2.13-6.10] for obesity. The adjusted-PAR was 23.8% for overweight and 37.6% for obesity. Relatively feasible lifestyle changes of preventing overweight and obesity could substantially lower population diabetes incidence