Stability and changes in metabolically healthy overweight or obesity and risk of future diabetes: Niigata wellness study

OBJECTIVE: Stability and changes in obesity and metabolic health status from a baseline period and longitudinally investigated their impact on predicting future diabetes were assessed. METHODS: Studied were 27,478 Japanese individuals without diabetes. Metabolically healthy (MH) was indicated by having ≤1 among impaired fasting glucose, hypertension, hypertriglyceridemia and low HDL cholesterol concentration. Metabolically abnormal (MA) was indicated by having ≥2 of those metabolic abnormalities. A cut-off value of BMI 25.0 defined overweight or obesity (O) or normal weight (NW). Hazard ratio (HR) for diabetes for a 6-year period was investigated after changes in phenotypes were assessed during the previous 2 years. RESULTS: Compared with maintaining MH-NW, transitioning to MH-O from MH-NW resulted in a multivariate-adjusted HR of 1.96 (95% CI: 1.18, 3.25) for diabetes. With a stable MH-O the HR for diabetes was 2.59 (2.00, 3.34) while change from MH-O to MH-NW resulted in an HR of 1.30 (0.61, 2.76). Transitioning to MA-O from MH-O was associated with an HR of 7.09 (5.41, 9.30). With a stable MA-O the risk of diabetes was substantially elevated with an HR of 12.5 (10.5, 14.9). CONCLUSIONS: Examining the transitory nature of apparently benign or unhealthy obese phenotypes was effective for differentiating high-risk individuals for future diabetes.