Research presented at the Alzheimer’s Association International Conference in 2022 indicated that experiencing hypertensive disorders during pregnancy is associated with an increased risk of vascular dementia and accelerated brain aging.
Chronic/gestational hypertension and preeclampsia, collectively known as hypertensive disorders of pregnancy (HDP), are closely linked to heart disease later in life. However, few studies have connected these disorders with cognitive impairment. Key findings presented at AAIC 2022 include:
- Women with a history of HDP are more likely to develop vascular dementia in old age compared to those who did not experience hypertensive disorders during pregnancy.
- HDP, particularly chronic hypertension during pregnancy, is associated with white matter pathology, a predictor of cognitive decline, 15 years post-pregnancy.
- Women with severe preeclampsia have significantly higher levels of beta-amyloid, a brain change associated with Alzheimer’s disease, than those who did not experience HDP.
HDP affects about 1 in 7 pregnancies and is a major cause of maternal and fetal morbidity and mortality worldwide. It disproportionately impacts African-American, LatinX, Asian/Pacific Islander, and Native American populations.
Dr. Claire Sexton, Senior Director of Scientific Programs and Outreach at the Alzheimer’s Association, stated, “This is one of the first sets of longitudinal data linking hypertensive disorders during pregnancy with dementia in a large study cohort. Considering the severe short and long-term effects of HDP, early detection and treatment are crucial for protecting both the mother and the fetus.”
Increased Risk of Vascular Dementia Linked to HDP
To investigate the link between HDP and dementia in old age, Dr. Karen Schliep from the University of Utah Health and colleagues conducted a retrospective cohort study on 59,668 women who had experienced pregnancy. Women with a history of HDP had a higher adjusted risk of all-cause dementia compared to those who did not experience HDP by 1.37 times. Their risk of vascular dementia was 1.64 times higher and the risk of other related dementias, though not Alzheimer’s disease was 1.49 times higher. Both gestational hypertension and preeclampsia/eclampsia showed similar risks for vascular dementia.
Schliep noted, “Our findings confirm previous discoveries that preeclampsia is most closely associated with vascular dementia compared to Alzheimer’s or other types of dementia. These results suggest that women with a history of gestational hypertension may also face a high risk of vascular dementia, similar to those with a history of preeclampsia.”
HDP Linked to White Matter Pathology 15 Years Post-Pregnancy
Rowina Hussainali, a researcher at Erasmus University MC Medical Center, and her colleagues aimed to explore the long-term cerebrovascular health effects of HDP by investigating the link between HDP and markers of vascular brain pathology 15 years after pregnancy.
They studied 538 women from the Generation R study, including 445 women who did not experience HDP and 93 who did. The study included women with due dates between April 2002 and January 2006. Fifteen years later, some of these women underwent MRI scans to evaluate brain tissue volume and other pathology markers.
The researchers found that women who experienced HDP had 38% more white matter pathology compared to those who did not. This link was most pronounced in women with a history of gestational hypertension, who had 48% more white matter pathology than women with normal blood pressure during pregnancy. No differences were found for other brain pathology markers like brain infarcts or cerebral microbleeds. The onset of chronic hypertension after pregnancy strengthened these results, particularly in women who had gestational hypertension.
Hussainali remarked, “These data clearly show that a history of HDP is associated with increased brain damage 15 years post-pregnancy. Such damage can have lasting effects on cognitive function. Women with a history of HDP should be evaluated early for hypertension and other cardiovascular risk factors.”
Increased Markers of Brain Inflammation Linked to Preeclampsia
Preeclampsia, a severe hypertensive disorder of pregnancy, affects up to 8% of pregnancies. Many data points show that women with a history of preeclampsia accumulate health risks, including heart disease, later in life. Given its association with high cerebrovascular disease risk, Dr. Sonja Suvakov and her team at the Mayo Clinic investigated whether extracellular vesicles, small pockets released from brain cells, could be detected years after severe preeclampsia.
They found that women with a history of severe preeclampsia had significantly higher concentrations of extracellular vesicles positive for amyloid-beta, a protein involved in Alzheimer’s disease. They also discovered significant increases in vesicles positive for markers of cerebrovascular endothelial damage and inflammation, alongside increased circulating levels of beta-amyloid.
Suvakov stated, “These findings show that women with a history of preeclampsia have elevated levels of markers indicating neurovascular damage, which could negatively impact cognitive function. Further research is needed to fully understand the lifelong neurodegenerative and cognitive risks posed by a history of hypertensive disorders.”
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