乌鸦传媒

Preeclampsia raised the risk of young-onset dementia, a prospective study of nearly 2 million women in France showed.

Compared with pregnancies without hypertensive disorders, preeclampsia more than doubled the risk of dementia at a young age (HR 2.65, 95% CI 1.34-5.25), according to Valérie Olié, PhD, of Santé Publique France in Saint-Maurice, and co-authors.

The risk of young-onset dementia rose when preeclampsia occurred before 34 weeks' gestation (HR 4.15, 95% CI 1.30-13.14), or when it was superimposed with chronic hypertension (HR 4.76, 95% CI 1.49-15.22), Olié and colleagues reported in a research letter.

"This is a novel study because it identifies an association between a new disease and preeclampsia," noted Stephen Tong, PhD, and Roxanne Hastie, PhD, of the University of Melbourne in Australia, in an .

Of the 1,966,323 women in the study, only 128 -- less than 1% -- developed young-onset dementia, the editorialists observed.

"Hence, individuals who have had preeclampsia should be reassured that young-onset dementia remains a very rare condition," they pointed out. "Their absolute risk increases only imperceptibly."

Recent studies have reported relationships between hypertensive disorders of pregnancy, mostly preeclampsia, and late-life cognition. An 80-year retrospective study showed that women with hypertensive disorders of pregnancy had a higher risk of later-life . Women with gestational hypertension and preeclampsia also had a higher risk of dying before age 70.

"Over the last two decades, the life-long health consequences of preeclampsia have come into sharp focus," Tong and Hastie noted. "These risks are so consequential that many international clinical guidelines, such as the American Heart Association, now recognize that previous preeclampsia is an important risk factor for later cardiovascular diseases."

Young-onset dementia may be more prevalent than previously thought, though it during childbearing years are very rare (1.0 to 3.8 per 100,000 population). A recent U.K. Biobank study identified risk factors for dementia at young ages; preeclampsia was not among them.

Olié and colleagues analyzed information from the nationwide CONCEPTION cohort, which used data from the information system. Previous research from this cohort showed that preeclampsia was present in in France.

The database included all deliveries in France after 22 weeks' gestation from 2010 through 2018. The researchers followed women ages 30 or older without a history of dementia from delivery through December 2021, and adjusted findings for obesity, diabetes, tobacco smoking, drug or alcohol addiction, and social deprivation.

Nearly 2 million women were included in the study. The mean maternal age was 34.6 years.

Dementia was identified through hospital records over an average follow-up of 9 years. Women who developed young-onset dementia were older (36.4 vs 34.6 years), more frequently socially deprived (13.3% vs 12.0%), smokers (14.8% vs 9.0%), or had diabetes (2.3% vs 0.7%), compared with those without dementia.

The overall findings suggest a dose-dependent association between preeclampsia and early dementia risk, "with higher HRs for early-onset preeclampsia and superimposed preeclampsia," Olié and co-authors wrote. Severe preeclampsia, however, was not associated with young-onset dementia, which may be due to low statistical power in this subgroup.

"Although it is yet to be proven in clinical trials, it is plausible that after an episode of preeclampsia, adopting a healthy lifestyle may improve vascular health and reduce the risk of many serious cardiovascular conditions," the editorialists suggested.

"Furthermore, if the pathology causing an increased dementia risk is also mediated through poor vascular health, a healthy lifestyle may also mitigate this risk, too," they added. "If so, then the message is clear -- healthy diet, regular exercise, and engaging with primary health care physicians may reduce the risk of all these conditions associated with preeclampsia in one fell swoop."

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