Incidence and predictors of type 2 diabetes mellitus during 17 years of follow-up in the Golestan Cohort Study

In this study, we aimed to determine the incidence and predictors of type 2 Diabetes Mellitus (T2DM) in the Golestan Cohort Study (GCS). This study is a prospective population-based cohort study conducted in the Golestan province of Iran with the participation of 50,044 people aged 30 to 87 years between 2004 and 2008. Participants were followed up for 17 years for T2DM. The cumulative incidence of T2DM was 13.32% in the GCS. We observed hypertension (HTN) and dyslipidemia (DLP) increased the risk of T2DM 1.16 and 1.63 times relative to the healthy participants (RR: 1.16, 1.63, 95% CI : 1.102-1.222, 1.393-1.928, p < 0.001). For every one-unit increase in the body mass index (BMI), the risk of T2DM increased 1.09 times (RR: 1.09, 95% CI :1.086-1.106, p < 0.001). High-risk waist circumference (WC) increased the risk of T2DM by 1.89 times more than normal WC (RR: 1.89, 95% CI : 1.756-2.053, p < 0.001). Smokers had an 89% lower risk of T2DM than non-smokers (RR: 0.897, 95% CI : 0.814-0.989, p = 0.029). We conclude that environmental factors induce T2DM by affecting body fat. Also, other metabolic diseases could develop T2DM.