OBJECTIVES:Â The risk of cardiovascular disease among obese individuals without obesity-related metabolic abnormalities, referred to as MHO, is controversial. To compare the coronary artery calcium (CAC) scores of metabolically healthy obese (MHO) and metabolically healthy normal weight individuals in a large sample of apparently healthy men and women.
METHODS:Â Cross-sectional study comprised14,828 metabolically healthy adults 30 to 59 years of age with no known cardiovascular disease who underwent a health checkup exam including cardiac tomography estimation of CAC scores. Being metabolic healthy was defined as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance (HOMA-IR) <2.5.
RESULTS:Â MHO individuals had a higher prevalence of coronary calcification than those with normal weight. In multivariable adjusted models, the CAC score ratio comparing MHO to normal weight participants was 2.26 (95% CI 1.48 â€“ 3.43). In mediation analyses, further adjustment for metabolic risk factors markedly attenuated this association, which was no longer statistically significant (CAC score ratio 1.24, 95% CI 0.79 â€“ 1.96). These associations did not differ by clinically relevant subgroups.
CONCLUSIONS:Â MHO participants had a higher prevalence of subclinical coronary atherosclerosis compared to metabolically healthy normal weight participants, supporting that MHO is not a harmless condition. This association, however, was mediated by metabolic risk factors at levels below those considered abnormal, suggesting that label of metabolically healthy for obese subjects may be an artifact of the cut-off levels used in the definition of metabolic health.