A preliminary exploration of the association between hypertension and cognitive function and the mediating role of estimated glomerular filtration rate among older adults in a community in Shanghai

OBJECTIVE: To analyze the association between hypertension and cognitive impairment among older adults in Shanghai and assess the potential mediating effect of estimated glomerular filtration rate (eGFR) in this association. METHODS: From July 2016 to December 2019, a cross-sectional survey was conducted among 1 380 older adults aged ≥60 years in communities in 2 subdistricts of Xuhui District, Shanghai. General demographic data were collected, and the Montreal Cognitive Assessment (MoCA) was administered to assess the cognitive function of all included participants. Independent-samples t tests were used to compare MoCA scores between groups with different characteristics. A multiple linear regression model was used to analyze independent factors influencing cognitive function. A mediation model was further constructed, and the Bootstrap method was used to test the mediating effect of eGFR between hypertension and cognitive function. RESULTS: Univariate analysis showed that MoCA scores were significantly lower among individuals with a history of hypertension than among those without a history of hypertension [(21.33±4.51) points versus (22.26±4.18) points, P<0.001], and significantly lower among those with a history of cardiovascular and cerebrovascular disease than among those without such a history [(20.81±4.71) points versus (22.07±4.21) points, P<0.001]. After adjustment for confounding factors including age, sex, educational level, marital status, smoking history, and alcohol consumption history, multiple linear regression analysis showed that a history of hypertension (β=-0.055, 95%CI:-0.961～-0.047, P=0.031) and a history of cardiovascular and cerebrovascular disease (β=-0.077, 95%CI:-1.204～-0.261, P=0.002) were independent risk factors affecting cognitive function, while eGFR (β=0.090, 95%CI:0.013～0.058, P=0.002) was an independent protective factor. Mediation analysis indicated that eGFR had a significant partial mediating effect in the relationship between hypertension and cognitive function, with an indirect effect of -0.062, 95%CI:-0.126～-0.016, and a mediating effect accounting for 10.95% of the total effect. CONCLUSIONS: Hypertension is an important risk factor for impaired cognitive function and may negatively affect cognitive function by reducing glomerular filtration rate. Screening for hypertension and renal function should be strengthened, with early diagnosis and intervention for cognitive decline in older adults.