Martin Lindgren

Background Coronary heart disease remains the dominant cause of death worldwide. To improve cardiovascular disease prevention, knowledge of early key risk factors, especially those that are modifiable, is essential. The ongoing global obesity epidemic is of particular concern. We aimed to determine whether body mass index at conscription predicts early acute coronary events among men in Sweden. Methods and Results This was a population‐based Swedish cohort study of conscripts (n=1 668 921; mean age, 18.3 years; 1968–2005), with follow‐up through linkage to the nationwide Swedish patient and death registries. Risk of a first acute coronary event (hospitalization for acute myocardial infarction or coronary death) during follow‐up (1–48 years) was calculated with generalized additive models. Objective baseline measures of fitness and cognition were included in the models in secondary analyses. During follow‐up, there were 51 779 acute coronary events, of which 6457 (12.5%) were fatal within 30 days. Compared with men at the lowest end of the normal body mass index spectrum (body mass index, 18.5 kg/m 2 ), an increasing risk for a first acute coronary event was observed, with hazard ratios (HRs) peaking at 40 years of age. After multivariable adjustments, men with a body mass index of 35 kg/m 2 had an HR of 4.84 (95% CI, 4.29–5.46) for an event before the age of 40 years. Conclusions An increased risk of an early acute coronary event was detectable within normal levels of body weight at the age of 18 years, increasing to almost 5‐fold in the highest weight category at 40 years of age. Given increasing levels of body weight and prevalence of overweight and obesity in young adults, the current decrease in coronary heart disease incidence in Sweden may flatten or even reverse in the near future.