A study of almost 34,000 people in rural China has revealed that lowering blood pressure can reduce the risk of dementia in patients with hypertension.
The findings stem from phase 3 of the China Rural Hypertension Control Project (CRHC), led by cardiologist Yingxian Sun, M.D., Ph.D., of First Hospital of China Medical University in Shenyang. The findings were published in Nature Medicine on April 21.
Patients with uncontrolled hypertension from 326 villages were split into two groups; 163 villages received usual hypertension care, while the other 163 received intensive treatment for blood pressure (BP) reduction. In the intensive treatment group, 4.59% of patients had developed dementia after four years, compared to 5.4% in the group receiving usual treatment.
In a secondary measure, 17.2% of patients in the intensive BP lowering group developed cognitive impairment without meeting the criteria for dementia (CIND), compared to 20.7% of those receiving usual care.
“Reduction in BP was associated with a 15% lower risk of all-cause dementia and a 16% lower risk of CIND,” the authors wrote. “The CRHCP-3 trial provides strong evidence for the effectiveness of antihypertensive treatment in reducing the risk of dementia in patients with hypertension.”
The intensive hypertension treatment involved community healthcare providers, often called village doctors though they aren’t physicians, giving patients antihypertensive medications, coaching them on lifestyle changes and rigorously monitoring their BP to ensure it stayed within the targeted lower range. Patients who stuck with their usual care routine did not receive antihypertensive medications or at-home BP monitoring devices.
Previous studies have also indicated a link between high blood pressure and dementia risk. A 2023 analysis of 17 different studies with a combined total of 34,589 participants found that older adults with uncontrolled hypertension were 42% more likely to develop dementia than those whose hypertension was treated.
However, many past studies have been observational, or only measured dementia risk as a secondary outcome, the researchers noted in their paper. In comparison, phase 3 of the CRHC is instead a randomized trial specifically designed to test the effect of lowering BP on dementia risk.
Dementia is a global public health issue, with 57 million people affected by the disease around the world in 2021, according to the World Health Organization. Dementia has emerged as the leading cause of death in the U.K., sparking efforts in the country to fund new treatments and seek a potential link between GSK’s shingles vaccine and reduced dementia risk.