Effect of BP Meds on Dementia Risk Explored
Non-dihydropyridine calcium channel blockers and loop diuretics were associated with a lower risk of dementia independent of blood pressure variability (percent coefficient of variation [CV]) in the preceding 4 years, researchers found in a study published in Neurology.
There has been opposing research on whether specific antihypertensive drugs could delay or reduce the risk the dementia. Researchers from France conducted a prospective population-based cohort study (n=6,537) to determine the association between antihypertensive drug classes and incident dementia controlling for blood pressure (BP) variability in the preceding 4 years.
In order to classify drug exposure and measure BP, study authors created a 4-year time lag. BP variability was regressed against 9 drug classes and hazard ratios (HRs) were calculated for incident dementia according to drug class, and adjusted for mean BP, covariates, and BP variability or BP variability regression (BPVreg). The median follow-up was 8.4 years for a total of 49,032 person-years of survival.
Patients who developed dementia were characterized by higher systolic BP and lower CV-BPV but the diastolic BP and diastolic CV-BPV were not different from P<0.05, the authors noted.
Overall, the data showed a reduced dementia risk with non-dihydropyridine calcium channel blockers (HR 0.56, 95% CI: 0.31-1.00; P=0.05) and loop diuretics (HR 0.45, 95% CI: 0.22-0.93; P=0.03) after adjusting for CV-BPV. Specifically for antihypertensive users, results were similar for non-dihydropyridine calcium channel blockers and loop diuretics (HR 0.52 and HR 0.40, respectively).
A stratified analysis based on dementia subtype further showed 309 cases of Alzheimer's dementia and 85 cases of vascular dementia/mixed dementias. ACE inhibitors were associated with a lower risk of vascular dementia/mixed dementias (P=0.07) in a propensity-adjusted model including CV-BPV but it was not different from P<0.05.
Findings from this study add to existing literature by showing that systolic BP variability was not the primary mechanism by which antihypertensive drug classes reduce dementia risk. Neither non-dihydropyridine calcium channel blockers or loop diuretics decreased systolic BP variability indicating that other mechanisms may be at play. Further studies are warranted regarding the delay or mitigation of dementia risk and the interaction among BP, antihypertensive drugs, and BP variability.
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