Indoor solid fuel use for cooking and the risk of incidental non-fatal cardiovascular disease among middle-aged and elderly Chinese adults: a prospective cohort study

OBJECTIVES: The harm of indoor air pollution to health has gradually attracted attention, but the effect of indoor air pollution from burning solid fuels on incidental non-fatal cardiovascular disease (CVD) is not well understood. Under these circumstances, this study examined the association between solid fuel use and incidental non-fatal CVD. DESIGN: The prospective cohort study was conducted in 2011, 2013, 2015 and 2018. SETTING: The nationally representative survey was conducted in 28 provinces of China. PARTICIPANTS: This study included 13 544 middle-aged and elderly adults without CVD in the baseline survey, and they were followed for 7 years. OUTCOME MEASURES: First incidence of non-fatal CVD (heart disease or stroke). METHODS: Based on longitudinal data, Cox proportional hazards models were used to assess the effects of solid fuel use and persistent use on incidental CVD events. RESULTS: During the 7-year follow-up period, there were 1533 non-fatal CVD cases. A total of 7310 (54%) participants used solid fuel for cooking at the baseline survey, and 2998 (41%) users continued to use solid fuel. Solid fuel use was associated with incidental non-fatal CVD (HR: 1.18; 95% CI: 1.05 to 1.32) compared with clean fuel, and persistent solid fuel use might lead to a higher risk of incidental non-fatal CVD (HR: 1.38; 95% CI: 1.18 to 1.61) and heart disease (HR: 1.49; 95% CI: 1.24 to 1.81). In the subgroup analysis, the relationship remained significant in the female, elderly, rural and hypertensive groups. However, we found no significant interaction between these risk factors and fuel use (all p<0.05). CONCLUSIONS: This cohort study provides evidence for the effects of solid fuel use on incidental non-fatal CVD in middle-aged and elderly Chinese adults. Advocating for the use of clean energy and ventilation stoves is important to cardiovascular health.