Estimation of risk for diabetes according to the metabolically healthy status stratified by degree of obesity in Korean men

Although obesity is clearly identified as a risk factor for diabetes, the relationship between diabetes and metabolically healthy status of obesity is less clear. This study was aimed to evaluate the incidental risk of diabetes according to metabolically healthy status of obesity. 31,834 Korean men without diabetes categorized into six groups according to their metabolically healthy status stratified by degree of obesity were followed up for 5 years: metabolically healthy normal weight (MH-NW), metabolically healthy overweight (MH-OW), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MU-NW), metabolically unhealthy overweight (MU-OW), and metabolically unhealthy obese (MUO). Cox proportional hazards analysis was used to measure the risk for diabetes according to their categories. While overall incidence was 9.0 %, incidence of diabetes was in proportion to the degree of obesity and metabolically healthy status (MH-NW: 6.3 %, MH-OW: 7.5 %, MHO: 9.2 %, MU-NW: 11.8 %, MU-OW: 14.9 %, MUO: 20.1 %). When MH-NW was set as reference, the adjusted HRs (95 % CI) for diabetes of the MH-OW, MHO, MU-NW, MU-OW, MUO compared to MH-NW were 1.18 (1.06–1.32), 1.58 (1.03–2.41), 1.81 (1.61–2.04), 2.36 (2.11–2.63), and 3.47 (2.84–4.24), respectively. In conclusion, risk for diabetes was in proportion to the degree of obesity in both metabolically healthy and unhealthy group. Metabolically healthy status was more significant determinant for incident diabetes than obesity itself.