Coronary artery disease risk among obese metabolically healthy young men

Objective: The aim of this study was to assess coronary artery disease (CAD) risk among obese young men without metabolic risk factors. Design: A longitudinal study in a historical cohort. Methods: Incident CAD during a median follow-up of 6.1 years was assessed among 31 684 young men (mean age 31.2 +/- 5.7 years) of the Metabolic, Lifestyle and Nutrition Assessment in Young Adults (MELANY) cohort. Participants were categorized by BMI and the number of metabolic abnormalities (based on the Adult Treatment Panel-III). Metabolically healthy (MH) obesity was defined as BMI >= 30 kg/m(2) in the presence of normal blood pressure (BP) and normal levels of fasting glucose, triglyceride, and HDL-cholesterol (HDL-c) levels (n=599; 1.9%). Cox proportional hazard models were applied. Results: There were 198 new cases of CAD that were diagnosed during 209 971 person-years of follow-up, of which six cases occurred among MH obese. The incidence of CAD among MH lean, overweight, and obese participants was 0.23, 0.45, and 1.0/1000 person-years respectively. In a multivariable model adjusted for clinical and biochemical CAD risk factors, a higher CAD risk was observed among MH-obese (hazard ratio=3.08; 95% CI=1.10-8.68, P=0.033), compared to MH-normal weight subjects. This risk persisted when BMI was treated as a time-dependent variable, or when fasting glucose, HDL-c, triglycerides, or BP were added to the model. Similar results were also obtained when a more permissive definition of MH was used. Conclusions: Obesity may continue to contribute to increased risk for incident CAD in young men even in the presence of a healthy metabolic profile.