Blood pressure change patterns and accelerated cognitive decline: evidence from a national longitudinal cohort of middle-aged and older Chinese adults.

BACKGROUND: Blood pressure is a modifiable vascular risk factor for cognitive decline, but the association between dynamic blood pressure changes and subsequent cognitive deterioration remains unclear. This study aimed to examine whether systolic blood pressure (SBP) and diastolic blood pressure (DBP) change patterns were associated with cognitive decline among middle-aged and older Chinese adults. METHODS: Data were obtained from the China Health and Retirement Longitudinal Study. Participants aged 45 years or older with available blood pressure measurements in 2011 and 2013 and repeated cognitive assessments during follow-up were included. Individuals with baseline cognitive impairment were excluded. Blood pressure change patterns were defined separately for SBP and DBP using the baseline median values, 124/74 mmHg, and categorized as stable low, low-to-high, high-to-low, and stable high. Cognitive decline was assessed from Wave 2 to Wave 4 over approximately 5 years of follow-up. Cognitive function was assessed using memory, executive function, and orientation tests. Global cognitive z scores were calculated, and the annual rate of cognitive change was estimated. Multivariable linear regression models were used to evaluate associations between blood pressure change patterns and cognitive decline. RESULTS: A total of 3,245 participants were included. Compared with the stable low SBP group, participants with a low-to-high SBP pattern had significantly faster decline in global cognitive function after full adjustment (β = -0.038 SD/year, 95% CI: -0.065 to -0.011; P = 0.005). Similarly, the low-to-high DBP pattern was associated with accelerated global cognitive decline (β = -0.032 SD/year, 95% CI: -0.059 to -0.005; P = 0.021). High-to-low and stable high patterns of SBP or DBP were not significantly associated with cognitive decline. Domain-specific analyses showed that low-to-high DBP was associated with faster memory decline, whereas low-to-high SBP was associated with faster decline in orientation. Sensitivity findings were not uniform across alternative blood pressure definitions and model specifications. The associations remained statistically significant when the 130/80-mmHg threshold was used, but the effect estimates were attenuated and no longer statistically significant when the 140/90-mmHg threshold was applied. CONCLUSIONS: Among middle-aged and older Chinese adults, low-to-high SBP and DBP patterns were associated with faster subsequent cognitive decline, although results varied across alternative blood pressure specifications. Long-term monitoring and prevention of substantial blood pressure increases may be relevant to cognitive health.