If blood pressure values that are too high are effectively reduced, the risk of dementia is significantly reduced. Successful high blood pressure therapy can therefore also contribute to the prevention of dementia.
A research team led by Professor Jiang He from Tulane University presented the results of a study at the American Heart Association’s 2023 Scientific Session that suggests a clear connection between blood pressure reduction and the risk of dementia in people with high blood pressure.
High blood pressure and dementia
Previous observational studies had already shown that people with untreated high blood pressure have a 42 percent increased risk of dementia compared to healthy adults, while people with successfully treated high blood pressure do not have a significantly increased risk of dementia, reports Professor He.
Last year, researchers at the George Institute for Global Health found relatively reliable evidence in a study that lowering blood pressure can protect against dementia.
Study with around 34,000 participants
Professor He’s team has now examined the extent to which measures to lower blood pressure actually reduce the risk of dementia in around 34,000 participants from 326 villages in rural China.
All participants were at least 40 years old and suffered from untreated high blood pressure, defined as blood pressure values above 140/90 mm Hg or above 130/80 mm Hg in people at high risk of cardiovascular disease, the researchers explain.
In 163 villages, participants received a physician-guided intensive blood pressure intervention strategy over a period of four years, while in the other 163 villages usual care was provided by village doctors or general practitioners in township hospitals.
The goal in the intervention group was to reduce systolic blood pressure to less than 130 mm Hg and diastolic blood pressure to less than 80 mm Hg, the research team reports. In addition to lifestyle changes, blood pressure-lowering medications were also an essential element.
Significant reduction in blood pressure achieved
According to the researchers, after 48 months, the average blood pressure in the intervention group was 128/73 mm Hg, compared to 148/81 mm Hg in the usual care group. On average, the systolic blood pressure fell by 22 mm Hg and the diastolic blood pressure fell by 9 mm Hg among the people in the intervention group.
At the end of the four-year study period, cognitive function assessments were also performed and, where appropriate, a final diagnosis of dementia from any cause or cognitive impairment (no dementia) was made by a panel of experts.
Dementia risk significantly reduced
The subsequent data analysis showed that people in the intervention group had a 15 percent lower risk of a dementia diagnosis and a 16 percent lower risk of cognitive impairment compared to the other group, the researchers report.
In addition, fewer serious adverse events such as hospitalizations and deaths from any cause occurred in the intervention group.
The intensive treatment strategy resulted in a significant improvement in blood pressure values as well as a reduced risk of cognitive impairment and a lower risk of dementia.
Lowering blood pressure to prevent dementia?
“This is the first large, randomized study to show that lowering blood pressure effectively reduces the risk of dementia in people with high blood pressure,” summarizes Professor He. Accordingly, an effective strategy against high blood pressure could also reduce the global burden of dementia.
In addition to medication, lifestyle changes, which primarily include sufficient exercise and a healthy diet, are promising approaches here. For example, another recently published study showed that cutting out salt can lower blood pressure as much as medication.
But the intestinal flora could also make a contribution to lowering blood pressure. In a study, researchers at the University of Hong Kong were able to identify two probiotics that have a blood pressure-lowering effect and may open up new therapeutic approaches in the future.
Regardless of how blood pressure is reduced in the case of hypertension, various other positive health effects can be hoped for, as high blood pressure is also considered a risk factor for strokes, heart attacks and other serious illnesses. (fp)