The combined effects of household solid fuel use and hypertension on the risk of stroke

Hypertension and household air pollution are both attributable risk factors for stroke. The study explored their joint effects in a prospective cohort. A total of 17096 adults were included in Jurong cohort. Weighted Cox regression models were used to assess the stroke risk. Crossover analysis was used to evaluate the combined effects. The population attributable fraction ( PAF ) was calculated to evaluate stroke risk attributable to solid fuel use. After followed up 8.66 (5.53,8.70) years, 1,104 stroke cases occurred. Solid fuel use was associated with an increased risk 55.6% of stroke, whereas, the association was attenuated after adjustment ( HR =1.077, 95% CI : 0.929-1.249). Among those taking no antihypertensives and normotensive individuals, the associated effect still exists ( HR =1.284, 95% CI : 1.041-1.583, HR =1.551, 95% CI : 1.130-2.129). Moreover, compared with clean fuel users with normotension, clean fuel users with hypertension, solid fuel users with normotension, and solid fuel users with hypertension had increased risks of stroke after excluding those taking antihypertensives with HR s (95% CI ) of 1.181 (0.948-1.472), 1.463 (1.108-1.933), and 1.395 (1.061-1.835), respectively. Heterogeneity was observed between the hypertensive individuals without antihypertensive and normotensive populations ( I 2 =0.588). In addition, solid fuel contributed a higher PAF to stroke among individuals without hypertension ( PAF =0.144, 95% CI =0.051-0.239). The PAF changed after excluding the individuals with antihypertensive treatment, although did not reach statistical significance. This study highlights the impact of solid fuel use on stroke among the population without hypertension, especially in prehypertension, emphasizing the necessity to reduce solid fuel use for stroke prevention. • Solid fuel use increased the risk of stroke in the normotensive population, particularly, among prehypertensive individuals. • Hypertension may cover up the relationship between solid fuel use and stroke. • Solid fuel use reduction in normotensive populations may provide greater benefits for stroke risk. • Antihypertensives use may reduce the independent effect of solid fuel on stroke among participants with hypertension.