Obesity at a young age is associated with development of diabetes mellitus: A prospective cohort study in rural China

Objectives We aimed to assess the age-dependent association of obesity with the risk of developing diabetes mellitus (DM) among a low-income population in China. Methods In this prospective cohort study, we estimated the hazard ratios (HR) for the association of body mass index (BMI) with DM risk from 1991 to 2014, after adjusting for other possible risk factors, using Cox-regression analysis. Results A total of 971 participants were followed up for 23 years in this study. The incidence of DM in this population was as high as 467.0/100,000 person-years. Compared with normal weight, the HR (and 95% confidence interval [CI]) for overweight affecting DM risk was 2.23 (1.45-3.41) overall, including 2.43 (1.05-5.63) for men and 2.17 (1.31-3.59) for women. The HR associated with the impact of obesity was 3.59 (2.06-6.27) overall, including 6.04 (1.84-19.81) for men and 3.23 (1.69-6.16) for women. Being overweight had a significant association with DM for people aged 40-49 years (HR, 1.99; 95% CI, 1.03-3.84); the HR for an association between DM and obesity was the highest among individuals aged 30-39 years (HR, 4.43; 95% CI, 1.84-10.67). There was no statistical significance between BMI and DM among individuals aged >= 50 years. Conclusions These findings suggest that obesity is associated with developing DM in rural China, especially among adults aged <50 years. Weight management is the highest priority for reducing the heavy burden of DM.