Is the cognitive function of older patients affected by antihypertensive treatment? Results from 54 months of the Medical Research Council's treatment trial of hypertension in older adults

Abstract

Objective: To establish whether initiation of treatment with diuretic or β blocker is associated over 54 months with change in cognitive function. Design: A cognitive substudy, nested within a randomised, placebo controlled, single blind trial. Setting: 226 general practices from the Medical Research Council's general practice research framework. Subjects: A subset of 2584 subjects sequentially recruited from among the 4396 participants aged 65-74 in the trial of treatment of hypertension in older adults. The 4396 subjects were randomised to receive diuretic, β blocker, or placebo. Subjects had mean systolic pressures of 160-209 mm Hg and mean diastolic pressures Outcome measures: The rate of change in paired associate learning test (PALT) and trail making test part A (TMT) scores (administered at entry and at 1, 9, 21, and 54 months) over time. Results: There was no difference in the mean learning test coefficients (rate of change of score over time) between the three treatments: diuretic -0.31 (95% confidence interval -0.23 to -0.39), β blocker -0.33 (-0.25 to -0.41), placebo -0.30, (-0.24 to -0.36). There was also no difference in the mean trail making coefficients (rate of change in time taken to complete over time) between the three groups: diuretic -2.73 (95% confidence interval -3.57 to -1.88), β blocker -2.08 (-3.29 to -0.87), placebo -3.01, (-3.69 to -2.32). A less conservative protocol analysis confirmed this negative finding. Conclusion: Treating moderate hypertension in older people is unlikely to influence, for better or for worse, subsequent cognitive function. Key messages Studies have shown that treating hypertension in older adults reduces cardiovascular mortality and morbidity Treating moderate hypertension with either diuretic or β blocker does not seem to influence cognitive function Concerns about damaging cognition should not deter doctors from treating hypertension in older patients Age should no longer be a factor in the decision to initiate antihypertensive treatment