Higher diastolic blood pressure aged 40‐44 is associated with declining cognition and increasing white matter lesions over 8‐12 year follow up.

Abstract

AbstractBackgroundBackground: High midlife blood pressure (BP) is an accepted risk factor for later life cognitive decline and dementia. However, the changing patterns of systolic and diastolic (DBP) blood pressure from our 40s to our 60s highlight the need for a more sophisticated understanding of the relationships between BP during the midlife period and cognition as well as brain measures, including white matter lesion (WHL) volume as a marker of small vessel disease.MethodThe Personality and total health (PATH) study is an Australian longitudinal population based cohort with four waves of follow‐up at approximately 4‐year intervals (W1‐4). Data was used from two PATH cohorts, one aged 40‐44 at W1 (40s) and the other aged 60‐64 at W1 (60s) and included the subset of participants with BP (W1), neuropsychological testing (W1, W4), imaging (MRI)(40s W2, W4, 60s W1, W4). Linear regression models with relevant adjustment, including antihypertensive use, were used to examine the relationship between baseline BP and change in imaging and cognition over time. P≤0.01 was taken as significant.ResultData were available for 492 participants,’40s’: 218 (53% female) ‘60s’: 274 (42%). Key findings were that higher DBP at ages 40‐44 was associated with a significant decline in performance over the subsequent 12 years on the symbol digit modalities test (slope‐0.7 (95% CI ‐1.2, ‐0.3) p=0.002) and to a lesser extent, trail making A (0.9 (0.2, 1.6)p=0.01) per 10mmHg increment. There were no associations for recall, digit span or dexterity tests. There were no associations for the 60s. Higher DBP aged 60‐64 was associated with a 31% (95% CI 13%, 51%) increase in WML over 12 years (p<0.001) per 10mmHg and a similar but less strong relationship (13% (3%, 24%) in the 40s over 8 years (p=0.008). There were no relationships between change in hippocampal or total brain volume. There were no significant relationships for SBP.ConclusionHigher DBP was associated with decline in processing speed in the 40s and growth of WML overall. The next step is to examine the relationship between change in BP and change in cognition and imaging measures.