ABSTRACT
Objectives
Indoor air pollution related to household solid fuel use for heating and cooking and social disconnection including loneliness and social isolation are reported to increase the risk of mild cognitive impairment (MCI), but their joint associations have not yet been examined. This study aimed to explore their joint associations with MCI.
Methods
Data were from five waves (2011–2020) of the China Health and Retirement Longitudinal Study (CHARLS) among 5314 cognitively intact participants aged ≥ 60 years at baseline. Cox proportional hazards models were applied to explore the associations of household solid fuel use and social disconnection with MCI.
Results
During the 9-year follow-up, 644 (12.5%) participants experienced MCI. Participants exposed to both solid fuel use and social disconnection (HR = 1.417, 95% CI = 1.149–1.747) had higher risk of MCI than those exposed to one factor alone (HR = 1.195–1.218, 95% CI = 0.944–1.572). There were significant additive interaction (RERI = 0.274, 95% CI = 0.065–0.482) and multiplicative interaction (p for interaction = 0.017) between household fuel types for heating and loneliness. The association of loneliness with higher risk of MCI was not significant in both subgroups, but the values of HR in the solid fuel use subgroup (HR = 1.142, 95% CI = 0.997–1.307, p = 0.055) were higher than that in the clean fuel use subgroup (HR = 0.853, 95% CI = 0.695–1.046, p = 0.126).
Conclusion
Household solid fuel use and social disconnection may be independently and jointly associated with MCI. These findings implicate that social and health strategies should address the reduction of solid fuel use and improvement of social connections to maintain cognitive function among older adults.