ASSOCIATION BETWEEN HOUSEHOLD SOLID FUEL USE AND RISK OF SARCOPENIA: DATA FROM THE CHINA HEALTH AND RETIREMENT LONGITUDINAL STUDY

Objective: Few studies have examined the effects of air pollutants on the risk of sarcopenia, especially air pollution from indoor settings. We aimed to explore the cross-sectional and longitudinal associations of household solid fuel use for cooking and heating, separately and simultaneously, with risk of sarcopenia. Design and method: Cross-sectional and follow-up data from the China Health and Retirement Longitudinal Study (CHARLS) were used. Multivariable-adjusted generalized linear models and Cox proportional hazards regression models were performed to estimate the odds ratio (OR) and hazard ratio (HR) with 95% confidence intervals (CI), respectively. We also calculated the extent of interaction or joint relations of sociodemographic and behavioral factors and household fuel use with sarcopenia. Results: 11,494 (median age: 57.0 years; 47.4% males) and 7,483 (median age: 57.0 years; 46.9% males) participants were included in the cross-sectional and follow-up study, respectively. After fully adjusting for covariates, both using solid fuels for cooking and heating were positively associated with incident sarcopenia in the longitudinal analyses, with hazard ratio (HR) (95% CI) of 1.56 (1.28-1.89) and 1.26 (1.04-1.52), respectively. When comparing to those using clean fuels for both cooking and heating, participants using solid fuels for both cooking and heating were more likely to have incident sarcopenia [HR (95% CI):1.52 (1.19-1.93)]. In addition, compared with those persistently used clean fuel for cooking, significantly higher risk of new-onset sarcopenia was found in participants persistently used solid fuels [HR (95% CI):2.05 (1.55-2.71)]. Moreover, significant multiplicative and/or additive interactions were observed between age, smoking status and solid fuel use for cooking with risk of sarcopenia (all P for interaction < 0.05). Similar results were found in the cross-sectional analyses. Conclusions: Household solid fuel use was significantly associated with higher risk of sarcopenia. In addition, ageing and smoking had synergetic effects with burning solid fuels for increasing the risk of sarcopenia. Our results highlighted the importance of taking multi-pronged measures from both aspects of air pollution and health behavior to prevent sarcopenia and promote healthy ageing.