The effects of household solid fuel use on self-reported and performance-based physical functioning in middle-aged and older Chinese populations: A cross-sectional study.

BACKGROUND: Physical limitation, which has been linked to outdoor air pollution exposure in previous studies, is a risk factor for disability and even for premature death. Although people often spend more time indoors, the relationship between indoor air pollution and physical function has not been fully explored. METHODS: The associations of household fuel types with self-reported and performance-based physical functioning were tested on a total of 12,458 participants in the China Health and Retirement Longitudinal Study (CHARL), using generalized linear models and logistic regression models. Additionally, subgroup analyses according to smoking status and number of chronic diseases, were performed regarding these associations. RESULTS: Our results revealed that after adjusting for potential confounds, solid fuel use in cooking showed -0.08 (-0.13, -0.04) and -0.15 (-0.23, -0.06) declines in self-reported and performance-based physical functioning scores (higher scores means fewer physical limitations), when compared with cleaner groups, respectively. Considering these outcomes as binary variables, the ORs (95% CIs) for abnormal self-reported and performance-based physical functioning in the solid fuel cooking group were 1.226 (1.053-1.427) and 1.194 (1.072-1.330), respectively. No significant association between heating fuel use and physical functioning was observed. Additionally, no modification effect of smoking status and the number of chronic diseases on the association between cooking fuel use and performance-based physical functioning was observed (P > 0.05). CONCLUSION: Our findings suggested that solid cooking fuel use may be associated with self-reported and performance-based physical functioning decline of middle-aged and elder Chinese populations.