Time in target range of systolic blood pressure and cognitive outcomes in patients with hypertension

Abstract Background Blood pressure (BP) is a dynamic measure that fluctuates over time. However, conventional BP control indicators may not adequately reflect the variability of BP during a period of time. Methods We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), which compared systolic blood pressure (SBP) targets of <120 mmHg (intensive) and <140 mmHg (standard) among patients with hypertension and high cardiac risks. The target ranges were defined as 110 to 130 mmHg in intensive treatment arm and 120 to 140 mmHg in standard treatment arm, respectively. Time in target range (TTR) was calculated based on SBP measurements recorded during the first 3‐month follow‐up using linear interpolation method. The Fine‐Gray competing risk regression models were used to evaluate the association between TTR and cognitive outcomes. Results A total of 7965 patients with the mean (SD) age of 68.0 (9.2) years were included, and 35% were female. Patients with higher TTR were younger, more likely to be male and take <3 BP‐lowering agents. Compared to the last quartile, the first quartile of TTR was significantly associated with a higher risk of probable dementia (HR: 1.74; 95% CI: 1.22–2.46; p = 0.002) and the composite of probable dementia or mild cognitive impairment (HR: 1.26; 95% CI: 1.03–1.55; p = 0.025). The risk of probable dementia and the composite outcome increased with per quartile decrease of TTR (HR: 1.18; 95% CI: 1.06–1.30; p = 0.002 and HR: 1.07; 95% CI: 1.00–1.14; p = 0.036). Sensitivity analyses showed similar results after adjusting mean SBP during the first 3‐month follow‐up. Conclusions In this secondary analysis of SPRINT data, TTR was independently associated with probable dementia among patients with hypertension, suggesting that TTR could be used as a practical metric of BP control to evaluate the risk of dementia in older adults. Registration URL: https://www.clinicaltrials.gov ; Identifier: NCT01206062.