Systolic blood pressure (SBP) time in target range (TTR) is an independent predictor for probable dementia, according to findings from a post hoc analysis published in the journal Hypertension.
Hypertension and SBP variability have been associated with dementia risk. It remains unclear whether the novel metric SBP TTR may also be a predictor for dementia risk.
To evaluate this relationship, data were sourced from the Systolic Blood Pressure Intervention Trial Memory and Cognition in Decreased Hypertension, (SPRINT MIND; ClinicalTrials.gov Identifier: NCT01206062) study, which was a multicenter, randomized, controlled, open-label trial comparing intensive and standard SBP targets. Cognitive outcomes among 8,298 patients were evaluated on the basis of SBP TTR between baseline and 3 months. The intensive SBP target was defined as 110-130 mmHg and the standard target as 120-140 mmHg.
The patients in the first (n=2,763), second (n=2,779), and third (n=2,757) tertiles of TTR were mean age, 68.4, 68.1, and 67.2 years (P <.001); 38.6%, 35.7%, and 30.3% were women (P <.001); 32.0%, 29.4%, and 30.4% were Black; they had a body mass index (BMI) of 29.7, 29.9, and 30.1 kg/m2 (P =.011); 17.5%, 17.3%, and 15.0% had a history of cardiovascular disease (P =.024); and, 56.3%, 49.3%, and 44.8% were randomly assigned to the intensive SBP target group (P <.001), respectively.
During a median follow-up of 5.05 years, the overall incidence rate (IR) of probable dementia was 0.77 per 100 person-years (py), mild cognitive impairment (MCI) was 1.63 per 100 py, and probable dementia or MCI was 2.18 per 100 py. In general, the rate of probable dementia was higher among individuals who spent less time in range.
In the fully adjusted model, SBP TTR associated with lower risk for probable dementia (adjusted hazard ratio [aHR], 0.86; 95% CI, 0.76-0.98; P =.023). Similar trends were observed when the target range was adjusted to 110-140 mmHg.
Stratified by TTR, compared with those who were in range less than 43% of the time, risk for probable dementia was lower for those in range 43%-<76% (hazard ratio [HR], 0.70; 95% CI, 0.53-0.93) and 76% or more (HR, 0.62; 95% CI, 0.45-0.84) of the time (P =.002).
No significant trends were observed for the risk for MCI or probable dementia or MCI with SBP TTR.
The limitations of this study included the post hoc design and the fact that patients with prior stroke or diabetes were excluded, making it unclear whether these findings are generalizable for those patient populations.
Researchers concluded, “In this post hoc analysis of SPRINT MIND, higher time in SBP target range was significantly associated with a lower risk of probable dementia, independent of mean SBP. Maintaining consistent BP within 110 to 140 mmHg over time may be beneficial for dementia prevention.”
Li S, Jiang C, Wang Y, et al. Systolic blood pressure time in target range and cognitive outcomes: insights from the SPRINT MIND trial. Hypertension. Published online May 11, 2023. doi:10.1161/HYPERTENSIONAHA.122.20711