Dementia risk with antihypertensive use and blood pressure variability: A cohort study

Abstract

<p><b>Objective:</b> To determine the association between discrete antihypertensive drug classes and incident dementia controlling for blood pressure variability (BPV) in the preceding 4 years.</p> <p><b>Methods:</b> A total of 6,537 participants (mean age 79 years, 62% women) in a prospective population-based cohort were followed up for incident dementia. A 4-year time lag period was created to classify drug exposure and measure blood pressure. BPV (percent coefficient of variation [CV]) was regressed against 9 antihypertensive drug classes (BPV_reg). Cox regression models were employed to determine hazard ratios (HRs) for incident dementia thereafter according to drug class, adjusted for mean blood pressure, covariates, and BPV or BPV_reg.</p><p><b>Results:</b> Over a median 8.4 years follow-up (interquartile range 6.7-9.0), lower dementia risk was associated with nondihydropyridine calcium channel blocker (HR 0.56; 95% confidence interval [CI] 0.31-1.00, <i>p</i> = 0.05) and loop diuretics (HR 0.45; 95% CI 0.22-0.93, <i>p</i> = 0.03) after adjusting for CV-BPV. Similar findings were obtained in analyses restricted to antihypertensive drug users for nondihydropyridine calcium channel blocker (HR 0.52; 95% CI 0.28-0.95, <i>p</i> = 0.03) and loop diuretics (HR 0.40; 95% CI 0.19-0.83, <i>p</i> = 0.01). All systolic BPV × antihypertensive drug interaction terms were not different from <i>p</i> < 0.05.</p><p><b>Conclusions:</b> Nondihydropyridine calcium channel blocker and loop diuretics were associated with a reduced dementia risk independent of CV-BPV in the preceding 4 years. Systolic BPV was not the primary mechanism through which antihypertensive drug classes lower dementia risk.</p>