Gender differences in the relationship between smoking and frailty: results from the Beijing Longitudinal Study of Aging.

BACKGROUND Smoking is common in China, where the population is aging rapidly. This study evaluated the relationship between smoking and frailty and their joint association with health and survival in older Chinese men and women. METHODS Data came from the Beijing Longitudinal Study of Aging, a representative cohort study with a 15-year follow-up. Community-dwelling people (n = 3257) aged more than 55 years at baseline were followed between 1992 and 2007, during which time 51% died. A frailty index (FI) was constructed from 28 self-reported health deficits. RESULTS Almost half (1,485 people; 45.6%) of the participants reported smoking at baseline (66.8% men, 25.3% women). On average, male smokers were frailer (FI = 0.17±0.13) than male nonsmokers (FI = 0.13±0.10; p = .038). No such differences were seen in women. Men who smoked had the lowest survival probability; female nonsmokers had the highest. Compared with female nonsmokers, the risk of death for male smokers was 1.58 (95% CI = 1.41-1.95; p < .001), adjusted for age and education. Across all FI values, female smokers and male nonsmokers had comparable survival rates. CONCLUSION Smoking was associated with an increased rate of both worsening health and mortality. At all levels of health status, as defined by deficit accumulation, women who smoked lost the survival advantage conferred by their sex.