Weight status in young adulthood and survival after cardiovascular diseases and cancer

Background: Some studies have suggested that overweight is associated with lower mortality, but these results may be affected by reverse causality. We analysed how body mass index (BMI) in young adulthood is associated with mortality in the general population and after the diagnoses of coronary heart disease (CHD), stroke and cancer.

Methods: BMI was measured at an average age of 18 years in 734 438 Swedish men born in 1950-65. Diagnoses of CHD, stroke and cancer as well as all-cause mortality were derived from registers covering the whole population, up to 31 December 2010. The follow-up of 24.56 million person-years included 33 067 cases of mortality and 19 843 CHD, 13 578 stroke and 27 365 cancer diagnoses. Hazard ratios (HR) [with 95% confidence intervals (CI)] were estimated by the Cox proportional hazards model.

Results: Higher mortality in the whole cohort (HR = 1.26, 1.21-1.32) as well as after the diagnosis of CHD (HR = 1.33, 1.09-1.63) or cancer (HR = 1.13, 1.01-1.25) was found in moderately overweight men (BMI 25.0-27.4 kg/m(2)) as compared with normal weight men (BMI 20.1-22.4 kg/m(2)); for stroke patients the result for the same BMI categories was not statistically significant (HR = 1.17, 0.94-1.45). Mortality increased with increasing weight status and was highest in obese men (BMI >30 kg/m(2)): HR = 2.17 (2.02-2.34) for the whole cohort, 2.35 (1.81-3.05) after the diagnosis of CHD, 2.08 (1.56-2.77) after stroke and 1.68 (1.40-2.01) after cancer.

Conclusions: Even moderate overweight in young adulthood increases all-cause mortality and mortality after the diagnosis of CHD, stroke and cancer in men. Preventing overweight in young adulthood remains as an important public health issue.