Metabolically healthy obesity and cardiovascular events: A nationwide cohort study

Aims Whether obesity is associated with a higher risk of cardiovascular events in the absence of metabolic risk factors is a matter of debate. We evaluated the associations among metabolically healthy obesity (MHO) and different types of incident cardiovascular events in a contemporary population. Methods All patients discharged from French hospitals in 2013 with at least 5 years of follow-up and without a history of major adverse cardiovascular event (myocardial infarction, heart failure [HF], ischemic stroke or cardiovascular death, MACE-HF) or underweight/malnutrition were identified. They were categorized by phenotypes defined by obesity and 3 metabolic abnormalities (diabetes mellitus, hypertension, and hyperlipidemia). Hazard ratios for cardiovascular events during follow-up were adjusted on age, sex and smoking status at baseline. Results In total, 2,873,039 individuals were included in the analysis, among whom 272,838 (9.5%) had obesity. During a mean follow-up of 4.9 years, when pooling men and women, individuals with MHO had a higher risk of MACE-HF (multivariate-adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI]: 1.19-1.24), new-onset HF (HR 1.34, 95%CI 1.31-1.37), and AF (HR 1.33, 95%CI 1.30-1.37) compared with individuals with no obesity and 0 metabolic abnormalities. By contrast, risks were not higher for myocardial infarction (HR 0.92, 95%CI 0.87-0.98), ischemic stroke (HR 0.93, 95%CI 0.88-0.98) and cardiovascular death (HR 0.99, 95%CI 0.93-1.04). MHO in men was associated with higher risk of clinical events compared to MH men with normal weight (HR 1.12 to 1.80) while women with MHO had lower risk for most events than MH women with normal weight (HR 0.49 to 0.99). Conclusions In a large and contemporary analysis of patients seen in French hospitals, individuals with MHO did not have a higher risk of myocardial infarction, ischemic stroke or cardiovascular death than metabolically healthy individuals with no obesity. By contrast they had a higher risk of new-onset HF and new onset AF. Notable differences were however observed in men and women in the sex-stratified analysis. This article is protected by copyright. All rights reserved.