Maintaining Metabolically Healthy Overweight and Risk of Incident Type 2 Diabetes or Cardiovascular Disease - Special Issue

Background: Recent studies reveal that metabolically healthy obesity, which is free from the metabolic complications of obesity at present, is a risk of incident diabetes or cardiovascular disease (CVD). It may be because many metabolically healthy obesity individuals transit to metabolically abnormal obesity over time. However, the association between maintaining metabolically healthy obesity and incident diabetes or CVD is still unclear. Methods: 2190 participants without diabetes and/or CVD were examined at baseline and at 5-year follow-up, using a retrospective cohort study design. Metabolically abnormal was defined as having ? 2 of metabolic abnormalities, hypertension, hypertriglyceridemia, low HDL cholesterol and impaired fasting glucose. Overweight was defined as BMI ? 23 kg/ m2, which is recommended by WHO for Asian. Adjusted odds ratio (OR) and 95% confidence interval (CI) for incident diabetes or CVD at follow-up were estimated adjusting for potential confounders, compared to maintaining metabolically healthy non-overweight (MHNO). Results: At the follow-up examination, 82 participants developed diabetes. Crude incident proportions of diabetes were 0.6% in maintained MHNO (case/N = 5/859) and 1.3% in maintained metabolically healthy overweight (MHO)(4/314). Adjusted OR for incident diabetes of maintaining MHO was 1.71 (95% CI 0.42-6.57, P = 0.438). At the follow-up examination, 51 participants developed CVD. Crude incident proportions of CVD were 0.8% in maintained MHNO (7/859) and 1.6% in maintained MHO (5/314). Adjusted OR for incident CVD of maintaining MHO was 1.42 (95% CI 0.41-4.56, P = 0.565). Conclusions: Maintaining MHO phenotype was not associated with higher risk of incident diabetes or CVD.