Incidence of Metabolic Syndrome in Adults with Healthy Weight, Normal Weight Obesity, and Overweight/obesity

Objectives: The aim of this study was to estimate the incidence of metabolic syndrome (MetS) in individuals with a healthy weight (HWI), normal weight obesity (NWO), or overweight/obesity (OWO).

Methods: In all, 787 adults belonging to a 1978/1979 birth cohort from Ribeirão Preto were placed into one of three groups: HWI (body mass index [BMI] ≥18.5 and <25 kg/m + ∑skinfolds ≤90th percentile); NWO (BMI ≥18.5 and <25 kg/m +∑skinfolds >90th percentile); and OWO (BMI ≥25 kg/m +∑skinfolds >90th percentile). Those diagnosed with MetS at the 23 to 25 y of age were excluded according to Joint Interim Statement criteria. The incidence of MetS and its components in individuals 37 to 39 y of age was evaluated by Poisson regression with robust estimation of variance, which was adjusted for family income; physical activity level; and daily intake of calories, lipids, and added sugar.

Results: MetS was detected in 279 adults at 37 to 39 y of age. NWO and OWO individuals showed higher risk ratios (RRs) for the development of MetS (RR,1.87; 95% confidence interval [CI], 1.36-2.57; RR, 1.61; 95% CI, 1.29-2.03), increased blood glucose levels (RR, 1.77; 95% CI, 1.12-2.79; RR, 1.51; 95% CI, 1.12-2.04), and increased waist circumferences (RR, 1.46; 95% CI, 1.32-1.61; RR, 1.50; 95% CI, 1.38-1.62). There was a higher risk for increased blood pressure (RR, 1.72; 95% CI, 1.35-2.19) among OWO individuals, but not among those with NWO.

Conclusion: Individuals with NWO have a risk ratio for MetS similar to individuals with OWO. This demonstrates the need to assess body fat percentages, even in BMI-designated normal weight individuals, both for prevention and management of obesity.