A large study in rural China found that reducing blood pressure lowered the risk of all-cause dementia among adult patients with uncontrolled hypertension.

The findings came from the China Rural Hypertension Control Project Phase-3, a 48-month cluster-randomized trial in which researchers enrolled 33,995 individuals aged 40 years and older from 326 villages. Half of the participants were assigned to an intervention group managed by trained nonphysician health care providers using a stepped-care protocol to reach blood pressure targets below 130/80 mmHg. The remaining villages received the usual care.

After 4 years, the intervention group had a 15% lower risk of all-cause dementia compared with the control group. Dementia developed in 4.6% of the participants in the intervention group vs 5.4% of those in the usual care group. The relative risk was 0.85.

Systolic blood pressure in the intervention group declined by an average of 22 mmHg, and diastolic pressure by 9 mmHg. In comparison, the usual care group saw smaller reductions of 7 and 6 mmHg, respectively. By the end of the trial, 68% of the intervention group participants had reached the target blood pressure compared with 15% of the usual care participants.

Additionally, those in the intervention group took an average of 3 antihypertensive medications compared with about one in the control group. They were also more likely to use Angiotensin-converting enzyme inhibitors, calcium channel blockers, and diuretics. Medication adherence was 88% in the intervention group vs 66% in the usual care group.

The researchers also evaluated cognitive impairment without dementia. Among the participants in the intervention group, 17% of them developed this condition compared with 21% among those in the control group. The intervention group also had fewer deaths and serious adverse events.

The researchers found that the benefits remained significant after adjusting for variables such as age, sex, education, health history, and cardiovascular risk. Subgroup analyses confirmed consistent effects across different populations, including older adults and those at higher risk for cardiovascular disease.

The trial was among the largest to demonstrate that real-world blood pressure control can lower dementia risk. It underscored the potential of nonphysician health care workers in hypertension management and strengthened the case for blood pressure reduction as a dementia prevention strategy.

Full disclosures can be found in the study.

Source: Nature Medicine