Can the use of solid fuels increase the burden of multisite pain among middle-aged and older adults in China?

Background The relationship between indoor fuel use and multisite body pain remains unclear. This study aims to explore the potential association between solid fuel use and multisite pain burden disorders (MPBD). Methods This study was based on data from the China Health and Retirement Longitudinal Study (CHARLS) and conducted a longitudinal analysis of Chinese adults aged 45 years and older, with an average follow-up period of 6.8 years. Indoor fuel use was categorized into solid fuels and clean fuels, and further distinguished between heating and cooking applications. Participants reporting pain in more than seven body sites were defined as having MPBD. Cox regression was used to assess the hazard ratios (HR) and 95% confidence intervals (CIs) associated with fuel use and fuel switch. Results During the follow-up period, there were 1,201 (26.17%) cases of MPBD in the heating analysis and 1,525 (25.31%) cases in the cooking analysis. Compared to using clean fuels, the use of solid fuels for heating (HR = 1.21, 95% CI = 1.02–1.44) or cooking (HR = 1.20, 95% CI = 1.04–1.38) was associated with a higher risk of MPBD. Additionally, using solid fuels for both heating and cooking corresponded to an even higher risk (HR = 1.24, 95% CI = 1.00–1.53). In the fuel-switching analysis, compared with consistently using clean fuel, consistently using solid fuel for cooking (HR = 1.41, 95% CI: 1.22–1.62) was associated with a higher risk of MPBD. Compared with consistently using solid fuel, switching to clean fuel (HR = 0.80, 95% CI: 0.67–0.95) and consistently using clean fuel (HR = 0.71, 95% CI: 0.62–0.82) were associated with a lower risk of MPBD. No significant association was observed for heating fuel after full adjustment for covariates. Conclusion The use of solid fuels for heating or cooking was associated with a higher risk of MPBD, while switching to clean fuels may help reduce this risk.