The study
A cohort study of 172 patients with an average age of 79 years between 2009 and 2012 aimed to measure cognitive function using their MMSE (mini-mental state examination) scores.
The findings
1 MMSE scores of patients with a daytime systolic BP of <128 decreased faster (over the nine-month follow up period) than patients with a daytime systolic BP of 129 -144, or >145.
2 This association was deemed significant only in patients with dementia and those with mild cognitive impairment who were taking anti-hypertensive medications.
3 The association between consultation room BPs and MMSE was much weaker than the association between daytime BP and MMSE.
What does this mean for GPs?
Lowering systolic BP excessively may be detrimental to the cognitive function of elderly patients with dementia or cognitive impairment. This effect, and the potential collateral harms (such as falls and poor nutrition) must be considered carefully when treating hypertension in the elderly.
Ambulatory/home BP monitoring, rather than consultation room BP, is especially important in elderly patients with dementia.
Daytime systolic BP of 130-145 may be the most suitable range for elderly patients with dementia or cognitive impairment.
The paper
JAMA Internal Medicine March 2015
Dr Hamed Khan is a GP in the emergency department of St George’s, London, and a clinical lecturer. He tweets as @drhamedkhan.
