Body mass index categories and mortality risk in US adults: the effect of overweight and obesity on advancing death.

OBJECTIVES

We examined the association of body mass index with all-cause and cardiovascular disease (CVD)-specific mortality risks among US adults and calculated the rate advancement period by which death is advanced among the exposed groups.

METHODS

We used data from the Third National Health and Nutrition Examination Survey (1988-1994) linked to the National Death Index mortality file with follow-up to 2006 (n = 16 868). We used Cox proportional hazards regression to estimate the rate of dying and rate advancement period for all-cause and CVD-specific mortality for overweight and obese adults relative to their normal-weight counterparts.

RESULTS

Compared with normal-weight adults, obese adults had at least 20% significantly higher rate of dying of all-cause or CVD. These rates advanced death by 3.7 years (grades II and III obesity) for all-cause mortality and between 1.6 (grade I obesity) and 5.0 years (grade III obesity) for CVD-specific mortality. The burden of obesity was greatest among adults aged 45 to 64 years for all-cause and CVD-specific mortality and among women for all-cause mortality.

CONCLUSIONS

These findings highlight the impact of the obesity epidemic on mortality risk and premature deaths among US adults.