Preeclampsia may drive risk for young-onset dementia

Key takeaways:

• A preeclampsia diagnosis was associated with risk for early-onset dementia.
• Women who developed early-onset dementia were more likely to be older at delivery, smokers or have diabetes.

Women diagnosed with preeclampsia were 2.6 times more likely to develop early-onset dementia during 9 years of follow-up compared with women who did not have a hypertensive disorder of pregnancy, according to registry data.

Hypertensive disorders of pregnancy are the second leading cause of maternal death behind maternal hemorrhage and are a significant cause of short- and long-term maternal and offspring morbidity worldwide. Data show women with preeclampsia are at higher risk for developing CV and renal complications, with risk persisting decades after the pregnancy.

“Recently, those with preeclampsia were described as having a threefold higher risk of late-onset vascular dementia after a mean follow-up of 20 years,” Jacques Blacher, MD, PhD, of Hotel Dieu University Hospital, France, and colleagues wrote in a research letter published in JAMA Network Open. “This cohort study investigated whether preeclampsia and other hypertensive disorders of pregnancy were associated with an increased risk of young-onset dementia years after the pregnancy.”

Researchers analyzed data from 1,966,323 women aged 30 years or older with no history of dementia and deliveries after 22 weeks’ gestation from 2010 to 2018, using data from the French national health insurance information system. The mean age of women at delivery was 35 years. Researchers followed the women after delivery through Dec. 31, 2021, assessing exposures to hypertensive disorders of pregnancy and adjusting for obesity, diabetes, tobacco smoking and social deprivation.

Within the cohort, 128 women, or fewer than 1%, developed dementia, identified using primary diagnosis for hospitalization during mean follow-up of 9 years.

Compared with women without dementia, those who developed young-onset dementia were older (mean age, 36.4 years vs. 34.6 years), were more frequently socially deprived (13.3% vs. 12%), were more likely to be smokers (14.8% vs. 9%) and were more likely to have diabetes (2.3% vs. 0.7%).

Researchers found that a preeclampsia diagnosis was associated with an increased risk for young-onset dementia compared with pregnancy without a hypertensive disorder, with an HR of 2.65 (95% CI, 1.34-5.25). The risk for young-onset dementia nearly doubled when preeclampsia occurred before 34 weeks’ gestation, with an HR of 4.15 (95% CI, 1.3-13.14) or was superimposed on chronic hypertension (HR = 4.76; 95% CI, 1.49-15.22).

Severe preeclampsia was not associated with early-onset dementia; however, the finding may be due to low statistical power, according to the researchers.

“Although earlier studies have already reported cognitive function impairment and white matter lesions associated with preeclampsia, the present study is the first to show an increase in early-onset dementia risk,” the researchers wrote. “The results suggested a dose-dependent association, with higher HRs for early-onset preeclampsia and superimposed preeclampsia. The nonsignificant result regarding severe preeclampsia could be associated with the low statistical power in this subgroup, adding to the currently limited knowledge about risk factors of young-onset dementia.”

The researchers also noted that identifying dementia by hospital diagnoses may have “substantially underestimated” the incidence of the disease.

“The results add early-onset preeclampsia to the list of lifelong disease risks or health care implications of having had preeclampsia,” the researchers wrote.