Body Mass, Smoking, and Overall and Cause-Specific Mortality Among Older U.S. Adults

The authors examine the relationships between body mass, smoking, and overall and cause-specific mortality among U.S. adults aged 60 and older, using data from the National Health Interview Survey linked to the Multiple Cause of Death file and Cox proportional hazard models. The authors find that, compared to those who are normal weight, obese individuals have higher risks of overall, circulatory disease, and diabetes mortality. Furthermore, smoking status suppresses the relationships between obesity and overall, circulatory disease, and cancer mortality, and interacts with low body weight to increase mortality risks. Finally, underweight individuals initially face increased risks of death over the follow-up period, although over time their mortality risks diminish to those of normal-weight individuals, likely due to the presence of unobserved illness. Researchers and health practitioners must account for smoking status, body mass, and specific causes of death to understand and improve the health of our increasingly obese elderly population.