Early-onset dementia: A neurological sequela of preeclampsia

Women with preeclampsia are 2.6 times more likely to develop early-onset dementia compared with women who did not have a hypertensive disorder of pregnancy, according to a study published in JAMA Network Open.1 The risk was particularly high when preeclampsia occurs early in pregnancy or in conjunction with chronic hypertension.

To investigate the potential long-term effects of hypertensive disorders of pregnancy (HDPs), including preeclampsia, on the risk of developing young-onset dementia, French researchers conducted this study with 1,966,323 women. The mean maternal age was 34.6 years. Data for the study was taken from the nation-wide prospective Conception study, which used data from the French National Health Insurance Information System. All deliveries in France that occurred after 22 weeks of gestation between January 1, 2010, and December 31, 2018, were included in this database. Because this study employed anonymised data, it was approved by the French Data Protection Authority, which waived the informed consent requirement. The investigators identified and tracked every person 30 years of age or older who had no prior history of dementia from the time of delivery until December 31, 2021. The Cox proportional hazards regression models, both crude and adjusted, were used to compute the hazard ratios (HRs). The models were modified to account for social hardship, drug or alcohol addiction, obesity, diabetes, and tobacco smoking.

Less than one percent (n = 128) women developed dementia during the follow-up period of 9.0 years. The primary diagnosis for hospitalization was used to identify dementia. Compared to patients without dementia, participants who developed young-onset dementia tended to be older (34.6 vs 36.4 years); they were also more likely to be smokers (9.0% vs 14.8%), have diabetes (0.7% vs 2.3%) and be more often socially deprived (12.0% vs 13.3%).

Women who had preeclampsia during pregnancy had a 2.65 times higher risk of developing young-onset dementia compared to those who had pregnancies without hypertensive disorders of pregnancy with hazard ratio (HR) of 2.65. The risk for young-onset dementia almost doubled in cases with early-onset preeclampsia (before 34 weeks) with HR of 4.15. Preeclampsia superimposed on chronic hypertension was associated with nearly five times higher risk of developing young-onset dementia (HR 4.76).

On the other hand, severe preeclampsia was not found to be significantly associated with an increased risk of young-onset dementia (HR 1.45).

This study, which utilised a comprehensive national database, provides crucial insights into the long-term cognitive risks associated with hypertensive disorders of pregnancy. It calls for clinical awareness with enhanced surveillance and early intervention strategies for cognitive health in women with a history of hypertensive disorders of pregnancy. The researchers write, “The results add early-onset preeclampsia to the list of lifelong disease risks or health care implications of having had preeclampsia.”

Reference

1.    Valérie Olié, et al. Young-onset dementia among individuals with history of preeclampsia. JAMA Netw Open. 2024 May 1;7(5):e2412870. doi: 10.1001/jamanetworkopen.2024.12870.