Metabolically healthy obesity and cardiovascular events: A nationwide cohort study

To evaluate the associations between metabolically healthy obesity (MHO) and different types of incident cardiovascular events in a contemporary population.

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 (MACE; myocardial infarction, heart failure [HF], ischaemic stroke or cardiovascular death [MACE-HF]) or underweight/malnutrition were identified. They were categorized by phenotypes defined by obesity and three metabolic abnormalities (diabetes, hypertension and hyperlipidaemia). Hazard ratios (HRs) for cardiovascular events during follow-up were adjusted on age, sex and smoking status at baseline.

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 HR 1.22, 95% confidence interval [CI]: 1.19-1.24), new-onset HF (HR 1.34, 95% CI 1.31-1.37) and atrial fibrillation (AF; HR 1.33, 95% CI 1.30-1.37) compared with individuals with no obesity and zero metabolic abnormalities. By contrast, risks were not higher for myocardial infarction (HR 0.92, 95% CI 0.87-0.98), ischaemic 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 a higher risk of clinical events compared with metabolically healthy men of normal weight (HR 1.12-1.80), while women with MHO had a lower risk for most events than metabolically healthy women of normal weight (HR 0.49-0.99).

In a large and contemporary analysis of patients seen in French hospitals, individuals with MHO did not have a higher risk of myocardial infarction, ischaemic 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. However, notable differences were observed in men and women in the sex-stratified analysis.