Does current smoking predict future frailty? The English longitudinal study of ageing.

Background: smoking is the single most preventable cause of morbidity and mortality. The evidence on independent associations between smoking in later life and incident frailty is scarce. Objectives: to examine the effect of current smoking in older people on the risk of developing frailty, controlling for important confounders. Methods: we used data of 2,542 community-dwelling older people aged ≥60 years in England. Participants were classified as current smokers or non-smokers. Frailty was defined using modified Fried criteria. Multivariable logistic regression models were used to examine risk of 4-year incident frailty in current smokers compared with non-smokers, adjusted for demographic, socioeconomic and health variables. Results: of 2,542 participants, 261 and 2,281 were current smokers and non-smokers, respectively. The current smokers were significantly frailer, younger, with lower BMI, less educated, less wealthy and lonelier compared with non-smokers at baseline. In multivariable logistic regression models adjusting for age and gender, current smokers were twice as likely to develop frailty compared with non-smokers (odds ratio (OR) = 2.07, 95% confidence interval (CI) = 1.39-3.39, P = 0.001). The association is attenuated largely by controlling for socioeconomic status. Smoking remains significantly associated with incident frailty in fully adjusted models including age, gender, socioeconomic status, alcohol use, cognitive function and loneliness (OR = 1.60, 95% CI = 1.02-2.51, P = 0.04). The relationship is however attenuated when taking account of non-response bias through multiple imputation. Conclusions: current smokers compared with non-smokers were significantly more likely to develop frailty over 4 years among community-dwelling older people. Given that smoking is a modifiable lifestyle factor, smoking cessation may potentially prevent or delay developing frailty, even in old age. [ABSTRACT FROM AUTHOR]