The risk of vascular dementia is significantly increased among women with pregnancies complicated by preeclampsia (PE), according to a recent study published in the American Journal of Obstetrics & Gynecology.1
Takeaways
- Women with preeclampsia (PE) during pregnancy have a significantly higher risk of developing vascular dementia later in life.
- The study found a stronger association between PE and vascular dementia compared to other types of dementia.
- Previous research indicates that preeclampsia, especially if it occurs before 34 weeks' gestation, increases the risk of young-onset dementia.
- A systematic review and meta-analysis of 25 studies involving over 2.5 million women highlighted that PE is linked to a higher hazard ratio for dementia, particularly in women aged 65 and older.
- While the connection between PE and vascular dementia is evident, more research is needed to explore the relationship with Alzheimer's Disease and other forms of dementia.
Multiple cognitive conditions are classified as dementia, but the 2 most common are Alzheimer’s Disease and vascular dementia. Approximately 5% to 8% of patients aged over 60 years experience dementia, leading to disability, dependency and death. An annual cost of dementia worldwide of $2.8 trillion was estimated in 2019.
Early detection and optimization of risk factors for dementia is crucial for management. Hypertensive disorders in pregnancy (HDPs), which are a significant global health issue, have been linked to obesity, metabolic syndrome, and advancing maternal age worldwide. However, little is known about the connection between HDPs such as PE with dementia.
In a prior study, a link was reported between PE and young-onset dementia risk, with a hazard ratio of 2.65 vs normotensive patients.2 This increased to 4.15 for preeclampsia before 34 weeks’ gestation and 4.76 for preeclampsia superimposed on chronic hypertension.
To determine the associations between HDPs and subsequent maternal dementia, investigators conducted a systematic review and meta-analysis.1 Literature was identified through a systematic search of the Web of Science, Pubmed, CINAHL, and Psychinfo databases from database inception to July 31, 2022.
Studies were eligible if they had a population of pregnant women, an exposure of 1 or more HDP, normotensive pregnancies for comparison, and data about dementia or cognitive impairment. Relevant HDPs included PE, eclampsia, chronic hypertension, gestational hypertension, and PE superimposed on chronic hypertension.
Dementia with a known genetic or congenital etiology or with links to HDP that are not biologically plausible were excluded from the analysis. The secondary outcome analysis included studies evaluating quantitative changes in cognition score between women with and without HDPs. Categories of cognition tests included memory, attention, and executive function (EF).1
Title and abstract screening were performed by 2 independent authors. These authors also performed data extraction, which included year of publication, author, study design, exposure and outcome definitions, sample size, cofounders, and crude and adjusted estimates.
There were 25 studies included in the analysis, 10 of which assessed dementia and 16 of which assessed cognitive impairment. Across all 25 studies, there were 175,132 women with an HDP and 2,326,541 who were normotensive. Twenty-two of the studies had moderate or high quality, and all were conducted in the United States or Europe.1
Only 2 studies reported the association between undifferentiated HDP and all-cause dementia. The adjusted hazard ratio (aHR) was 1.44, indicating no significant association. However, associations were found for HDP subtypes. PE had an aHR of 1.18 for any dementia, which increased to 1.87 when restricted to women aged at least 65 years.
The association was stronger between PE and vascular dementia, with an aHR of 1.89 from 2 large, national, high-quality studies. When pooling data from 4 studies, the aHR between PE and Alzheimer’s Disease was 1.27, but increased to 1.92 when restricted to women aged over 65 years. However, data about other HDP subtypes remains limited.1
The association between PE and memory issues was assessed in 7 studies using 6 tools. However, only 1 tool reported a reduction in memory function among patients with a history of PE. Similarly, only 1 of 2 measures reported a decline in attention among women with a history of PE.
Three cognitive tools were used to assess EF, with only 1 finding an association with PE. Additionally, 3 tests evaluating EF between patients with and without HDPs found reduced cognition among those with any HDP.
These results indicated a significantly increased risk of future vascular dementia among women with PE during pregnancy. However, further research is needed to assess associations with Alzheimer’s Disease and other forms of dementia.1
References
- Carey C, Mulcahy E, McCarthyFP. Hypertensive disorders of pregnancy and the risk of maternal dementia: a systematic review and meta-analysis. American Journal of Obstetrics & Gynecology. 2024;231(2):196-210. doi:10.1016/j.ajog.2024.01.013
- Krewson C. Preeclampsia linked to elevated risk of young-onset dementia. Contemporary OB/GYN. May 30, 2024. Accessed August 2, 2024. https://www.contemporaryobgyn.net/view/preeclampsia-linked-to-elevated-risk-of-young-onset-dementia
