Background and objective: To assess the relation between body mass index (BMI) and the risk of death from various causes in a prospective cohort study.
Methods: In 6,192 obese patients (BMI > or =25 kg/m(2)) with mean BMI 36.6 kg/m(2) (SD 6.1) and mean age 40.4 years (SD 12.9) who had been referred to the obesity clinic of the Heinrich-Heine-University Düsseldorf, Germany, between 1961 and 1994, there were 1,058 deaths from all causes during a median follow-up time of 14.8 years. We calculated standardized mortality ratios (SMRs) with 95% confidence intervals (CIs) for death from predefined groups of diseases by using Germany as reference population.
Results: In both sexes, risk of death from cardiovascular diseases (men: SMR = 2.2, CI 1.9-2.5; women: SMR = 1.6, CI 1.5-1.8), from diabetes (men: SMR = 5.4, CI 3.2-8.7; women: SMR = 3.5, CI 2.6-4.8), and in men from digestive diseases (SMR = 1.6, CI 1.01-2.3) was significantly increased. In contrast to other studies, an association between obesity and all-cancer mortality could not be found. Only in morbidly obese women (BMI > or =40 kg/m(2)), all-cancer mortality was significantly increased (SMR = 1.5, CI 1.1-1.9).
Conclusion: Obesity is associated with increased risk of death from cardiovascular diseases and diabetes in both sexes, and from diseases of the digestive system in men.