Indoor air pollution and frailty: A cross-sectional and follow-up study among older Chinese adults

Abstract

Background: Previous studies have suggested that ambient air pollution negatively affects frailty, but whether indoor air pollution exposure affects frailty is unknown.

Method: This study was conducted on 4946 older adults (≥60 years) followed from baseline to 4 years in the Chinese Longitudinal Healthy Longevity Survey. Household fuel types and frailty were assessed with self-rated questionnaires and physical examination. The relationships between indoor air pollution and frailty via phenotypic frailty and a frailty index were explored with logistic regression models and Cox proportional hazard regression models in both a cross-sectional and follow-up design. Additionally, the effects of indoor air pollution on phenotypic frailty together with mild cognitive impairment (MCI) were further investigated.

Results: In the cross-sectional study, the adjusted ORs (95% CIs) for frailty assessment with the frailty index and phenotypic frailty were 1.28 (1.12, 1.46) and 1.36 (1.18, 1.57), respectively. Solid fuel use was a risk factor in prefrail/frail patients with [OR and 95% CI, 1.88 (1.41, 2.50)], or without MCI [OR and 95% CI, 1.37 (1.17, 1.61)], as compared with the groups with no phenotypic prefrailty/frailty and no MCI. Moreover, solid cooking fuel use was positively associated with the incidence of phenotypic prefrailty and frailty. The adjusted HRs (95% CIs) for phenotypic prefrailty and frailty were 1.26 (1.03, 1.55).

Conclusions: Solid cooking fuels can be regarded as a risk factor for frailty. Moreover, our findings suggest that more attention should be paid to solid cooking fuel using as it relates to phenotypic frailty together with MCI.

Keywords: Cohort; Frailty index; Older Chinese adults; Phenotypic frailty; Solid fuel use.