Cognitive impairment in uncontrolled vs controlled hypertension - systematic review and meta-analysis

Hypertension is a well-recognized risk factor for the development of cognitive impairment (CImp) and brain vasculogenic lesions. The aim of this systematic review was to assess whether adequate blood pressure control, compared with ineffective treatment, reduces the risk of CImp and brain structural abnormalities.

Between June and July 2024, three databases (MEDLINE, Embase, PsycINFO) were screened for studies comparing cognitive performance or brain damage in hypertensive adults. 2,613 unique records were identified, and ultimately 18 predominantly cross-sectional studies were included. Meta-analyses using a random-effect model were performed for CImp prevalence in 5 studies, for Mini-Mental State Examination and Montreal Cognitive Assessment scores in 3 studies, for verbal fluency outcomes in 3 studies, and for white matter hyperintensities assessed in magnetic resonance imaging in 4 studies.

The prevalence of CImp was lower in the group with well-controlled hypertension (OR 0.32, 95% CI: 0.13, 0.80), but the result was significant only among individuals ≥65 years of age. Similarly, white matter hyperintensities (WMH) tended to be less advanced among patients with controlled hypertension (SMD: 0.58, 95% CI: 0.08, 1.08). However, the individual neuropsychological tests analyzed (verbal fluency, delayed word recall, digit symbol substitution, and digit span) did not reveal significant differences between these groups.

Adequate control of hypertension may be associated with a lower prevalence of CImp and less advanced WMH. However, the association with CImp was confined to older adults (≥65 years) and was based on a small number of studies with considerable between-study heterogeneity.