Dementia risk due to blood pressure fluctuation

Observational studies have shown that higher systolic blood pressure variability (BPV) over time increases the risk of dementia later in life.

At 3, 6, 9 and 12 years, higher systolic BPV was associated with a higher risk of subsequent dementia, with HRs ranging from 1.02 (95% CI 1.01-1.04) to 1.10 (95% CI 1.05-1.16). range, Simin reported. He is co-author with Mahinrad, MD, PhD, of Northwestern University Feinberg School of Medicine in Chicago.

The relationship between systolic BPV and dementia risk was stronger in those not taking calcium channel blockers (P. interaction <0.05), the investigator Alzheimer’s disease and dementia.

Dr. Heather Snyder of the Alzheimer’s Association was not involved in the study.

“Previous studies have investigated the effects of antihypertensive treatment on the biology underlying Alzheimer’s disease and other dementias and cognitive decline, and whether treatment may influence disease risk and progression. , with mixed results,” Snyder said. MedPage Today“Cardiovascular-related interventions may be population- or intervention-timing specific.”

“More and more studies are looking more broadly at interventions that address blood pressure rather than specific interventions to determine their impact on cognitive decline and dementia,” she added.

One example is the Sprint MIND clinical trial. “In this study, aggressive treatment of systolic blood pressure reduced individuals who progressed from healthy cognition to mild cognitive impairment by nearly 20 percent,” he said. “Studies are ongoing to assess the impact of different interventions on progression to mild cognitive impairment and dementia.”

Independent of mean blood pressure level, BPV is emerging as a risk factor for dementia and Alzheimer’s disease in the elderly. Evidence suggests that both long-term (per-visit BPV) and short-term (minutes or days) elevations in BPV are associated with cognitive decline and dementia.

“However, most of these previous studies did not censor cases of dementia that developed during the period of BPV measurement, which raised concerns about reverse causal bias,” Mahinrad and co-authors noted. “In addition, although these studies assessed BPV over up to 6 years, the effects of longer-term exposure to BP fluctuations on dementia risk were not investigated.”

Mahinrad and colleagues evaluated long-term visit-to-visit BPV in two ongoing cohorts of community-dwelling older adults, the Rush Memory and Aging Project (MAP) and the Religious Orders Study (ROS). Both were prospective studies in older adults without dementia who consented to annual clinical evaluations and brain autopsies at death.

Blood pressure was measured with a sphygmomanometer by a trained research assistant at annual visits. BPV per visit was quantified over 3, 6, 9, and 12 years. Cognitive status was determined at each annual visit.

Researchers evaluated 2,234 participants who were 65 years of age or older and who participated in the study. Most (74%) were female and 94% were Caucasian. A total of 1,371 were taking antihypertensive drugs, of which 466 were taking calcium channel blockers.

The mean systolic blood pressure during the first 3, 6, 9, and 12 years was 134, 133, 132, and 131 mm Hg, respectively. Mean systolic BPV was 8.3%, 9.2%, 10%, and 10%, respectively.

During a median follow-up of 10 years, 668 participants developed dementia, 641 of whom were classified as having Alzheimer’s disease. After full adjustment, systolic BPV of ≥10% was associated with increased risk of dementia, and the best HR for systolic BPV was ≥12 years (HR 1.75, 95% CI 1.16-2.66). Each unit increase in systolic BPV over 3, 6, 9, and 12 years was associated with a 1.02-, 1.04-, 1.06-, and 1.10-fold increase in dementia risk (P.<0.05).

The researchers observed a significant moderating effect of calcium channel blockers on the relationship between systolic BPV and dementia risk. “Specifically, the period-specific association between systolic BPV and dementia risk was stronger among those who had not taken calcium channel blockers during the first 3 or 9 years.” They wrote. [renin-angiotensin system] modulators, and diuretics) did not change the results. ”

Mahinrad and co-authors noted that the study had several limitations. The sample consisted primarily of older Caucasian adults, and results may not apply to other groups. In addition, BPV per visit was measured annually. The effects of short fluctuations in blood pressure were not assessed.