番茄社区

PHILADELPHIA -- Intensive blood pressure control reduced dementia risk among individuals with hypertension, a randomized trial from rural China showed.

A village doctor-led intervention with a simple stepped-care protocol targeting a blood pressure under 130/80 mm Hg reduced occurrence of any dementia by a relative 15% compared with usual care over 4 years (1.12% vs 1.31% incidence per year, RR 0.85, P=0.0035).

The average 22/9.3 mm Hg greater reduction in blood pressure with intensive control also reduced incidence of non-dementia cognitive impairment by a similar degree (4.19% vs 5.02% per year, RR 0.84, P<0.0001), Jiang He, MD, PhD, of Tulane University in New Orleans, reported at the American Heart Association (AHA) meeting.

"This proven effective intervention should be widely scaled up to reduce the global burden of dementia," He concluded at the late-breaking clinical trial session.

"This is, importantly, the first definitive evidence of dementia risk reduction demonstrated in a randomized, controlled clinical trial," said session study discussant Daniel W. Jones, MD, a past president of the AHA. "To now know that we have a tool for prevention of dementia is overwhelming."

These findings extend the benefits seen in the , in which intensive blood pressure control that achieved a 14.8 mm Hg greater reduction in systolic blood pressure achieved reduction in mild cognitive impairment, but not dementia, over a mean of about 3 years.

"The trend was there, but they didn't have enough people to show it to be significant," noted Sandra Taler, MD, of the Mayo Clinic in Rochester, Minnesota and a member of the meeting program committee.

"I already tell patients that it can reduce the precursors to dementia and probably dementia," she said. "I think many people are motivated to treat their blood pressure if it will prevent dementia. That's bigger [to them] than stroke or death or whatever else, is keeping your mind. So I think this data is very important."

Taler cautioned, though, that there was no baseline cognitive screening to rule out preexisting cognitive impairment or dementia, although He noted that the comprehensive consent process likely would have led to exclusion of most people with preexisting dementia.

The trial included 33,995 adults ages 40 and older in 326 villages across three provinces in China. Enrollees had a mean untreated systolic blood pressure ≥140 mm Hg, a diastolic BP ≥90 mm Hg, or both from six measures on two different days. Alternatively, patients with a mean blood pressure as low as 130 mm Hg systolic or 80 mm Hg diastolic were allowed in if it was despite treatment or they had a history of coronary heart disease, chronic kidney disease, or diabetes.

The intensive blood pressure arm utilized village doctors under the training and supervision of primary care physicians and hypertension specialists. The village doctors started and titrated antihypertensive medications by treatment protocol, delivered discounted and free medications to patients, conducted lifestyle coaching, and taught home BP monitoring.

Systolic blood pressure dropped from a mean of 157/87.9 mm Hg in the intervention group at baseline to 127.6/72.6 mm Hg and from 155.4/87.2 to 147.7/81.0 mm Hg in the usual care group over 48 months. Intervention group patients averaged 3.0 antihypertensives on average compared with 1.3 in the usual care group.

"The effectiveness of BP reduction on all-cause dementia was consistent by subgroups of age, sex, education, cigarette smoking, body mass index, systolic blood pressure, and fasting plasma glucose at baseline," He noted.

Potentially hypotension-related adverse events were not significantly more common with no greater rate of injurious falls resulting in medical care or syncope events. Serious adverse events were less likely overall with the intensive blood pressure management.

While the intervention was in a different practice setting than typical in the United States, Keith Ferdinand, MD, of Tulane University in New Orleans, noted at an AHA press conference that "one of the questions is, 'Is this a model that we can use in other places around the globe in places with low resources and in the United States in disadvantaged populations?'"

Jones suggested that the model could be used in any setting with modifications, including in the United States.

A key question, he argued, is whether greater dementia risk reduction could be achieved by starting blood pressure management younger and going to even lower levels.

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