Association of smoking cessation with late-life frailty risk: the Singapore Chinese health study.

Objective: To examine whether smoking cessation, in terms of duration and age at quitting, was associated with late-life physical frailty. Design: Prospective population-based cohort study. Setting: Chinese living in Singapore. Participants: We analyzed data from 4,574 men (mean baseline age 52.7 years, range 45-65 years) enrolled in the Singapore Chinese Health Study. Measurements: Participants self-reported smoking behaviors at four time-points over a 20-year follow-up. Physical frailty was assessed in late life (mean age 73.6 years, range 65-88 years) using a modified Cardiovascular Health Study phenotype, incorporating weakness, slowness, exhaustion and weight loss. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for association with frailty. Results: Persistent smokers had higher odds of frailty compared to never smokers (OR: 1.34; 95% CI: 1.01-1.76). Those who had quit smoking within 10 years before frailty assessment also had increased odds (OR = 1.33; 95% CI: 0.86-2.01), albeit not statistically significant. The OR (95% CI) was attenuated to 1.08 (0.76-1.51) for those quitting 10-20 years and 0.97 (0.59-1.55) for those quitting >40 years. Those who quit smoking by age 60 years had similar odds relative to never smokers: OR was 1.05 (0.74-1.48) for quitting at ages 50-60 years and further reduced to 0.86 (0.57-1.25) for quitting at ages <40 years. Conclusion: While persistent smoking was associated with increased odds of late-life physical frailty, smoking cessation for at least 10 years, or before the age of 60 years, could mitigate this risk substantially.