Aggressive treatment to reach blood pressure targets may have adverse effects on cognitive function in patients with dementia and mild cognitive impairment (MCI), according to the results of a recent study (Mossello et al. JAMA Intern Med 2015;175:578-585).The cohort study analysed antihypertensive drug use and change from baseline in Mini-Mental State Examination (MMSE) scores in 172 older patients (mean age 79 years) at two memory clinics. Overall, 68% of patients had dementia and 32% had MCI; 69% were being treated with an antihypertensive drug. Mean MMSE score at baseline was 22.1.

MMSE change over a 9-month follow-up period was greater among patients in the lowest daytime systolic BP tertile (SBP < 128 mmHg) compared to the intermediate tertile (SBP 129-144 mmHg) and the highest tertile (SBP >145 mmHg). MMSE change was -2.8, -0.7 and -0.7 for the three tertiles, respectively. Low daytime SBP and antihypertensive drug use were independently associated with worsening MMSE in dementia and MCI subjects in a multivariate model incorporating age, baseline MMSE score and vascular comorbidity.

In a separate review, the authors recommended ambulatory BP monitoring rather than periodic assessments to reduce the risk of overtreatment with antihypertensive agents (Mossello & Simoni. Monaldi Arch Chest Ddis 2016;84:730). Frail elderly patients requiring a more cautious BP lowering may be identified through brief cognitive screening and motor assessment. The authors added that the most appropriate BP targets need to be identified in elderly patients with dementia.