Metabolic Health, Obesity, and Cardiovascular Disease: 2015-2016 National Health and Nutrition Examination Survey

The metabolically unhealthy normal weight (MUN) and metabolically healthy obese (MHO) phenotypes are abnormal metabolic states. The purpose of this study was to report the frequency of the strictly defined MHO and MUN phenotypes and the association between metabolic phenotype and 10-year Framingham cardiovascular disease (CVD) risk score using a sample taken from the 2015-2016 National Health and Nutrition Examination Survey.

A cross-sectional sample of 2,316 participants age 18-79 years with complete metabolic health information were selected from the 2015-2016 dataset and included in the present analysis. Metabolic health was defined as the absence of all metabolic abnormalities as outlined by the National Cholesterol Education Program Adult Treatment Panel III criteria, excluding waist circumference. Obesity was defined as body mass index ≥30 kg/m² or waist > 88.9 cm for females or > 101.6 cm for males.

Frequency of the MHO phenotype was 5.5% and the MUN was 44.3%. After adjustment for all covariates, Framingham CVD risk score was higher in the MUN (b = 1.74,p < 0.001) and metabolically unhealthy obese (b = 3.32,p < 0.001) phenotypes that used BMI to define obesity, and the MHO phenotype had a slight protective effect (b = -2.25,p < 0.001) when waist circumference was used as the measure of obesity.

Metabolically unhealthy phenotypes had higher CVD risk, while the MHO phenotype was not at any greater risk than the metabolically healthy normal weight.