Among older adults with mild cognitive deficits, discontinuing the use of antihypertensive medications did not improve their cognitive, psychological and general daily functioning.
Lead researcher Justine E.F. Moonen, MD, of Leiden University Medical Center in the Netherlands, and colleagues published the results of their randomized trial online in JAMA Internal Medicine on Aug. 24.
The researchers enrolled 385 participants from 128 general practices in the Netherlands from June 26, 2011, through Aug. 23, 2013. All participants were at least 75 years old, had mild cognitive deficits and systolic blood pressure of 160 mm Hg or less, received antihypertensive treatment and did not have serious cardiovascular disease.
They were randomly assigned to parallel discontinuation (the intervention group) or continuation (the control group) of antihypertensive treatment. Six weeks after randomization, physicians withdrew antihypertensive treatment in the intervention group participants until they had a maximum increase of 200 mm Hg in systolic blood pressure. During that time period, physicians monitored blood pressure on a weekly basis.
At six, 10 and 16-week follow-ups, systolic and diastolic blood pressure were significantly higher in the intervention group compared with the control group. After 16 weeks, the mean systolic blood pressure increased by 5.4 mm Hg and the mean diastolic blood pressure increased by 1.3 mm Hg in the intervention group. Meanwhile, among the control group, the mean systolic blood pressure decreased by 2 mm Hg and the mean diastolic blood pressure decreased by 1.3 mm Hg.
The groups did not significantly differ in terms of change in overall cognition compound scores, executive function, memory, psychomotor speed, symptoms of apathy, depression and quality of life.
The researchers also conducted exploratory analyses that showed no benefit of discontinuing antihypertensive medications in older participants with orthostatic hypotension, worse cognitive or general daily functioning, lower cerebral blood flow or more white matter hyperintensities, microbleeds and/or lacunar infarcts.
They mentioned a few possible explanations for the intervention’s inability to improve outcomes. They may have unintentionally selected a population with a relatively intact cerebral autoregulation who could not increase their cerebral perfusion. They chose participants who did not have cardiovascular disease, but they noted those with cardiovascular disease would more likely have their cerebral autoregulation impaired.
In addition, they said the study may have been underpowered and that the relationship between lower blood pressure and cognitive dysfunction may not be causal but rather attributed to common causes such as cardiac dysfunction or subtle neurodegenerative cerebral lesions in blood pressure regulation centers.
“Future randomized clinical trials with longer follow-up should determine whether older persons with impaired cerebral autoregulation might benefit from less stringent [blood pressure] targets,” the researchers wrote. “Nursing home residents would form a study population of interest because they often have more serious cerebrovascular disease and are thus prone to have an impaired cerebral autoregulation.”