Different hypertension thresholds and cognitive decline: a pooled analysis of three ageing cohorts

BACKGROUND: The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for high blood pressure (BP) in adults came up with a new definition of hypertension with a threshold BP level of 130/80 mmHg. But the 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines adhered to a conventional hypertension definition as BP ≥ 140/90 mmHg. We aimed to compare the trajectories of cognitive decline between participants with BP < 130/80 mmHg in all BP measurement waves and others with all BP < 140/90 mmHg. METHODS: This pooled analysis involved middle-aged and older participants from three nationally representative ageing cohorts, including the Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA), and the China Health Retirement Longitudinal Study (CHARLS). Participants were divided into the Normal (BP < 130/80 mmHg on all occasions throughout the study), the Borderline (BP < 140/90 mmHg on all occasions throughout the study but not in the Normal group), and the High (the rest of participants) BP groups. Global cognitive Z score was calculated from tests on memory, executive function, and orientation. RESULTS: A total of 17,590 participants (HRS 6964, median follow-ups 12 years; ELSA 5334, median follow-ups 16 years; CHARLS 5292, median follow-ups 7 years) were included. No significant difference in global cognitive decline rate was detected between the Normal and the borderline groups (men, pooled β = − 0.006 standard deviation [SD]/year; 95% confidence interval [CI], − 0.020 to 0.008; P = 0.377; women, pooled β = 0.006 SD/year; 95% CI − 0.005 to 0.018; P = 0.269). Participants in the High group had a significantly faster cognitive decline (men, pooled β = − 0.011 SD/year; 95% CI − 0.020 to − 0.002; P = 0.013; women, pooled β = − 0.017 SD/year; 95% CI − 0.026 to − 0.008; P < 0.001) than that in the Borderline group. CONCLUSIONS: Individuals in the Borderline group did not experience significantly faster cognitive decline compared with those in the Normal group. It might not be necessary for individuals with borderline BP (between 130/80 and 140/90 mmHg) to initiate antihypertension therapy in consideration of cognitive decline. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-021-02165-4.