An intensive blood-pressure lowering intervention significantly reduced the risk of developing dementia among adults with hypertension, according to study results released at the at the American Heart Association’s Scientific Sessions 2023.
The findings come from a prospective study conducted in China of a four year intervention to reduce BP in a population of 34,000 adults over the age of 40.
BP lowering is effective in reducing risk of dementia in patients with hypertension. This proven-effective intervention should be widely scaled up to reduce the global burden of dementia.
Study participants had untreated blood pressure of 140/90 mm Hg or higher, or 130/80 mm Hg or higher for people at high risk for cardiovascular disease or those currently taking blood pressure medication.
Half of the participants were randomly assigned to a doctor-led intensive blood pressure intervention strategy, which involved a stepped-care protocol to achieve a systolic BP goal of <130 mmHg and diastolic BP goal of <80 mm Hg. The other half of patients received usual care hypertension management from local doctors or primary care physicians.
The stepwise protocol for hypertension management included a treatment algorithm, selection of medication, review of contraindications of medications and, finally, strategies to adjust dose. They also provided discounted and free blood pressure medications to patients and conducted health coaching on lifestyle modifications, home blood-pressure measurement and medication adherence.
At the end of the 48-month study period, cognitive function assessments or screenings were conducted on participants by neurologists, who were blinded to randomization assignments.
The analysis found that the people in the BP-lowering intervention group showed significant improvement in BP control and reduced dementia and cognitive impairment compared to those who received usual care.
People in the intervention group had 15% lower risk of dementia and 16% lower risk of memory impairment compared to the group that received usual care.
The primary outcome of dementia was significantly lower in the intervention group compared to the usual care group (1.12% vs. 1.31% per year; relative risk with intervention: 0.85, 95% CI: 0.76 to 0.95; p=0.0035).
Cognitive impairment alone, the composite outcome of dementia or cognitive impairment, death from all causes, and the composite outcome of dementia or deaths were all significantly lower in the intervention group compared to the usual care group
The average blood pressure in the intervention group at 48 months was 128/73 mm Hg, compared to 148/81 mm Hg in the usual care group.
Serious adverse events, such as hospitalisations and death from all causes, were also less frequent in the intervention group.
“This is the first, large, randomised trial to demonstrate that lowering blood pressure is effective in reducing the risk of dementia in people with high blood pressure,” said study investigator Dr Jiang He, a professor of epidemiology and medicine and director of Tulane University’s Translational Science Institute in New Orleans.
“Previous observational studies have found that individuals with untreated hypertension have a 42% increased risk of dementia compared with healthy adults, while individuals with treated hypertension have no significant increase in dementia risk compared with healthy adults,” he noted
“This proven-effective intervention should be widely scaled up to reduce the global burden of dementia,” the study authors concluded.