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.