Impact of body mass index, metabolic health and weight change on incident diabetes in a Korean population.

Abstract

The aim of this study was to examine an impact of body mass index (BMI) and weight change on the risk of diabetes according to metabolic health status. Cohort study of 34,999 Korean men and women 30-59 years of age free of diabetes at baseline were followed-up annually or biennially for an average of 5.1 years. Being metabolically healthy was defined as not having any metabolic syndrome component. During 176,878.6 person-years of follow-up, 889 participants developed diabetes (incidence rate 5.0 per 1000 person-years). Compared to metabolically healthy normal-weight individuals, the adjusted hazard ratios for diabetes in metabolically unhealthy obese and in metabolically healthy obese were 13.7 (95% confidence interval [CI] 9.8-19.0) and 2.7 (95% CI: 1.7-4.3), respectively. The aHR (95% CI) for incident diabetes for weight changes of <-0.9, 0.5 to 2.0, and ≥2.1 kg compared to a weight change of -0.9 to 0.4 kg (reference) were 0.80 (0.66-0.97), 0.99 (0.82-1.20), and 1.24 (1.02-1.49), respectively (P-trend<0.001). In this large cohort of young and middle age Koreans, metabolic health status, obesity, and weight change were all independently associated with increased incidence of diabetes over 5 years of follow-up.