Association of hypertension status and exposure to atmospheric ozone improvement with cognitive decline in China

The impact of improving atmospheric ozone on the state of hypertension on changes in cognitive function has not received much attention. Using data from the China Health and Retirement Longitudinal Study (CHARLS), which included 8,700 people who were first assessed in 2011 and followed through 2018, this study aimed to investigate this association. The cognitive function examination measured three dimensions: memory, executive function, and orientation, from which a global cognitive function score was calculated. The study defined atmospheric ozone improvement as the decrease in average ozone concentration between the three-year periods preceding and succeeding 2011. Linear mixed models were used to investigate the effect of atmospheric ozone and hypertension status on cognitive function changes. Subsequent subgroup and interaction analyses were performed to evaluate potential effect changes on the aforementioned connection. Using non-hypertensive participants with improved atmospheric ozone as a reference, and after adjusting for potential variables, the multivariable-adjusted beta values for global function from those with hypertension and improved atmospheric ozone, non-hypertensive and unimproved atmospheric ozone, and hypertensive and unimproved atmospheric ozone were − 0.012 (95% CI: -0.021, -0.002), -0.014 (95% CI: -0.022, -0.006), and − 0.027 (95% CI: -0.036, -0.018), respectively (P for trend < 0.001).Subgroup analysis revealed that the combined effects of hypertension and atmospheric ozone exposure status on cognition were more significant in older patients, females, non-exercisers, and people without depressive symptoms at baseline. Notably, none of the interactions between the subgroups were significant (all P-interaction > 0.05). In conclusion, our findings revealed a substantial joint influence of atmospheric ozone improvement and hypertension status on cognitive function change, implying that both health behaviors and environmental policies were crucial in the prevention of function impairment.