A systematic review of calcium channel blocker use and cognitive decline/dementia in the elderly

OBJECTIVE: Treating hypertension in those aged at least 80 years is now recommended; however, the best antihypertensive to choose remains unexplored. Calcium channel blocker (CCB) use has been associated with a decreased risk of incident dementia in a younger hypertensive group but with an increased risk of cognitive decline in the very elderly. Either result could have a large impact on a vulnerable population. The aim of this review was to assess the evidence relating CCB use to later cognitive decline or dementia in the very elderly. METHODS: A systematic review of the literature was carried out. The databases Medline, PubMed, Embase and Psychinfo were searched from 1980 to 22 August 2013. Abstracts were reviewed by two independent reviewers and papers meeting the inclusion criteria were extracted. RESULTS: One thousand, nine hundred and sixty-eight records were reviewed and 10 articles reporting on nine studies retained and extracted. Data were primarily from cohort studies. Only one reported a randomized controlled trial comparing CCBs with placebo. Populations, comparator groups, follow-up times, outcomes and exposure varied and overall results were mixed. It was not possible to combine all studies, but those reporting Alzheimer's disease outcomes were combined to produce an overall risk ratio of 0.79 (95% confidence interval 0.53-1.17). CONCLUSION: At present, there is no clear evidence to suggest that CCB use increases or decreases risk of cognitive decline or dementia in the very elderly. A robust clinical trial is now required to resolve this.