Explaining the obesity paradox: cardiovascular risk, weight change, and mortality during long-term follow-up in men

Abstract

AIMS: To examine life-long weight trajectories behind the 'obesity paradox', and whether cardiovascular disease (CVD) risk contributes. METHODS AND RESULTS: Cardiovascular disease risk and body mass index (BMI) at mean ages of 25, 47 (year 1974), and 73 years (year 2000) were available of a socioeconomically homogenous sample of 1114 men, without chronic diseases and diabetes in 1974. Overweight was defined as BMI > 25 kg/m(2), and 7-year mortality (2000-06) from the mean age of 73 years determined (188 deaths). Between 1974 and 2000, 44.3% (n = 494) were constantly overweight, 31.0% (n = 345) constantly normal weight, 12.2% (n = 136) moved from normal to overweight, and 12.5% (n = 139) moved from overweight to normal. The last group had highest CVD risk in midlife, and in late life more co-morbidities and greatest total mortality (P < 0.001). Adjusted mortality hazard ratio was 2.0 (95% confidence interval, CI 1.3-3.0; constantly normal weight group as referent). The hazard ratio remained similar (1.9, 95% CI 1.2-3.0) after adjustment for prevalent diseases in 2000. CONCLUSION: In old age, both normal weight and overweight men are a mixture of individuals with different weight trajectories during their life course. Overweight and high-CVD risk in midlife with subsequent weight decrease predict the worst prognosis in late life.