On 19 May, Dr Diarmaid Hughes and collaborators published a systematic review and meta-analysis in the JAMA journal, showing that treatment of hypertensive patients with blood pressure-lowering medication can reduce the risk of dementia and cognitive impairment. Clinical studies have identified a link between elevated blood pressure (or hypertension) and dementia, with studies showing that people with hypertension in middle age and later life are almost 50% more likely to develop dementia compared to people with normal blood pressure. Hypertension is a risk factor for multiple forms of dementia including vascular dementia and Alzheimer’s disease, due in part to the vascular damage caused by high blood pressure. However, the benefit of blood pressure-lowering medication for the prevention of dementia or cognitive impairment is unclear, as two recent large-scale trials (the SPRINT MIND and HOPE-3 studies) found opposing results. In undertaking their systematic review and meta-analysis, Dr. Hughes and colleagues hoped to determine whether blood pressure lowering using antihypertensive drugs was associated with a reduced risk of dementia.
In total, fourteen studies were selected for inclusion in the meta-analysis, comprising 96,158 participants who were followed up for an average duration of 49 months. At baseline, none of the trial participants were known to have dementia or cognitive impairment, and all trials included a treatment and control arm. The mean age of trial participants was 69, and the mean baseline systolic and diastolic blood pressures were 154/83 mmHg. Analysis of the trials that reported dementia or cognitive impairment outcomes revealed a 7% reduction in dementia and 7.5% reduction in cognitive impairment in participants receiving antihypertensive drugs. In trials that reported on progressive cognitive decline over the follow-up period, blood pressure-lowering treatment was associated with a 20.2% reduction in cognitive decline. Overall, blood pressure lowering with antihypertensive agents was associated with a statistically significant reduction in dementia or cognitive impairment. The original article in JAMA can be found here: https://bit.ly/2ZIB4DS
