Hypertensive disorders of pregnancy and the risk of dementia: a systematic review and meta-analysis of cohort studies

This study aimed to investigate the association between hypertensive disorders of pregnancy (HDP) and subsequent risk of dementia using a systematic review and meta-analysis of cohort studies. We searched PubMed and Scopus for eligible studies that investigated the association between HDP and dementia risk. Using the random-effects model, pooled hazard ratio (HR) and 95% confidence interval (CI) of dementia risk in women with HDP were calculated. We applied the I2 statistic to measure heterogeneity across studies and the test for funnel plot asymmetry to evaluate publication bias. Six cohort studies were eligible: three from the United States, two from Sweden, and one from Denmark. When combined, HDP was associated with the risk of dementia: pooled HR (95% CI) = 1.31 (1.12, 1.53). The heterogeneity across studies was moderate (I2 = 47.3%, p-heterogeneity = 0.091), but no signs of publication bias were detected. The association of HDP with vascular dementia was stronger than that with Alzheimer's disease: pooled HRs (95% CIs) = 1.66 (1.13, 2.43) and 1.29 (0.97, 1.72), respectively. In conclusion, HDP was associated with a higher risk of dementia and this association was more prominent with vascular dementia.