Lower blood pressure during antihypertensive treatment is associated with higher all-cause mortality and accelerated cognitive decline in the oldest-old-data from the Leiden 85-plus Study.

Background: the appropriateness of lowering systolic blood pressure remains controversial in the oldest-old. We tested whether systolic blood pressure is associated with all-cause mortality and change in cognitive function for patients prescribed antihypertensive treatment and those without treatment.

Methods: we studied participants in the population-based Leiden 85-plus cohort study. Baseline systolic blood pressure and use of antihypertensive treatment were predictors; all-cause mortality and change in cognitive function measured using the Mini-Mental State Examination were the outcomes. Grip strength was measured as a proxy for physical frailty. We used Cox proportional hazards and mixed-effects linear regression models to analyse the relationship between systolic blood pressure and both time to death and change in cognitive function. In sensitivity analyses, we excluded deaths within 1 year and restricted analyses to participants without a history of cardiovascular disease.

Results: of 570 participants, 249 (44%) were prescribed antihypertensive therapy. All-cause mortality was higher in participants with lower blood pressure prescribed antihypertensive treatment (HR 1.29 per 10 mmHg lower systolic blood pressure, 95% CI 1.15-1.46, P < 0.001). Participants taking antihypertensives showed an association between accelerated cognitive decline and lower blood pressure (annual mean change -0.35 points per 10 mmHg lower systolic blood pressure, 95% CI -0.60, -0.11, P = 0.004); decline in cognition was more rapid in those with lower hand grip strength. In participants not prescribed antihypertensive treatment, no significant associations were seen between blood pressure and either mortality or cognitive decline.

Conclusions: lower systolic blood pressure in the oldest-old taking antihypertensives was associated with higher mortality and faster decline in cognitive function.