Impact of obesity on long-term prognosis following acute myocardial infarction

OBJECTIVE: To evaluate the impact of obesity on mortality in patients with acute myocardial infarction. METHODS: This study comprises 6676 consecutive patients with acute myocardial infarction screened for entry into the Danish Trandolapril Cardiac Evaluation (TRACE) study. At baseline, body mass index (BMI) and waist to hip ratio (WHR) were measured. Survival status was determined after 8-10 years. RESULTS: BMI was used to divide patients into 4 groups: underweight, normal weight, overweight and obese. The normal weight group was used as reference for the other groups. WHR was divided in quartiles and the lowest quartile was used as reference for the three other quartiles. The prevalence of overweight (BMI 25-29.9 kg/m(2)) and obesity (BMI>30 kg/m(2)) were 48% and 13% in males and 31% and 13% in females. Obese patients were younger, less often smokers and more frequently suffered from diabetes and hypertension. In both men and women, there was no association between obesity assessed as BMI and mortality [men: adjusted RR=0.99 (0.85-1.14, p=0.3); women: adjusted RR=0.90 (0.74-1.10, p=0.2)]. Men with WHR in the upper quartile had an increased mortality [adjusted RR=1.21 (1.07-1.37, p<0.01)]. Increasing WHR in women showed a trend of increased mortality, although this was not significant [adjusted RR=1.13 (0.95-1.34, p=0.2)]. CONCLUSION: In patients with acute myocardial infarction overall obesity as assessed by body mass index is inversely related to mortality. However, abdominal obesity appears to be an independent predictor of all-cause mortality in men and perhaps also in women.