Sex differences in the relationship between household solid fuel use and incident stroke and the mediating role of depressive symptoms in middle-aged and older Chinese adults

Background Household solid fuel use is associated with a higher risk of a wide spectrum of health disorders. However, the sex-specific relationship between solid fuel use and incident stroke in older Chinese adults, as well as the potential mediating role of depressive symptoms, remains insufficiently explored. Methods This longitudinal study used data from the China Health and Retirement Longitudinal Study (CHARLS), including 13928 Chinese participants aged 45 years or older free of stroke at baseline. Logistic regression models were used to assess the relationship between solid fuel use, depressive symptoms, and the risk of stroke. To quantify the potential mediation role of depressive symptoms in the pathway from solid fuel use to new-onset stroke, a mediation analysis was performed. Results Of the 13928 adults (mean age of 58, 47.26% male), 917 (6.58%) participants documented the incident stroke. Solid fuel use was significantly associated with the increased incident stroke risk in the total population (OR = 1.27, 95% CI: 1.08–1.51) and female populations (OR = 1.40, 95% CI: 1.11–1.78) in the fully adjusted model. In addition, depressive symptoms could explain the pathway, with the significant mediating proportions up to 16.2%, regardless of whether the depressive symptoms presented as general depression or severe depression. The results of the stratified analysis also indicate that this mediating effect is present only among the female group. Conclusion Household solid fuel use significantly increased the risk of incident stroke, and depressive symptoms played a mediating role in the relationship. These findings highlight the need for integrated public health interventions in the areas of environmental pollution and mental health, with particular attention to women.