Delayed Decline of Cognitive Function by Antihypertensive Agents: A Cohort Study Linked with Genotype Data

BACKGROUND: Arterial hypertension is among factors with the potential for increasing the risk of cognitive impairment in elderly subjects. However, studies investigating the effects of antihypertensives on cognitive function have reported mixed results. METHODS: We have used the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) to investigate the effect of each class of antihypertensives, both as single and combined, in reducing the rate of conversion from normal to mild cognitive impairment (MCI). RESULTS: The use of antihypertensive drugs was associated with 21% (Hazard ratio: 0.79, p<01001) delay in the rate of conversion to MCI. This effect was modulated by age, gender, and genotypic APOE4 allele. Among different antihypertensive subclasses, calcium channel blockers (CCBs) (24%, HR: 0.76, P=0.004), diuretics (21%, HR: 0.79, P=0.006), and α1-adrenergic blockers (α1-ABs) (23%, HR: 0.77, P=0.034) significantly delayed the rate of MCI conversion. A significant effect was observed with the selective L-type voltage-gated CCBs, dihydropyridines, amlodipine (47%, HR=0.53, P<0.001) and nifedipine (49%, HR=0.51, P=0.012), whereas non-DHPs showed insignificant effect. Loop diuretics, potassium sparing diuretics, and thiazides all significantly reduced the rate of MCI conversion. Combination of α1-AB and diuretics led to synergistic effects; combination of vasodilators plus β-blockers (βBs), and α1-AB plus βBs led to additive effect in delaying the rate of MCI conversion, when compared to a single drug. CONCLUSION: Our results could have implications for the more effective treatment of hypertensive elderly adults who are likely to be at high risk of cognitive decline and dementia. The choice of combination of antihypertensive therapy should also consider the combination which would lead to an optimum benefit on cognitive function.