Association between high serum estradiol levels and delirium among hospitalized elderly women.

Background: Delirium is a common and serious disorder among hospitalized elderly individuals. We investigated the association between serum estradiol levels and incident delirium.

Methods: Longitudinal study of 141 women ≥ 70 years old admitted to a tertiary care hospital in Mexico City. All participants underwent a comprehensive geriatric assessment. Blood samples for cortisol and estradiol determination were obtained at hospital admission. Incident delirium was investigated until participants were discharged. Multivariate models were run to test the independent association between estradiol levels and incident delirium.

Results: Twenty-three (16.3%) participants developed delirium. Estradiol levels were higher among women with incident delirium compared with non-affected women. Multivariate logistic regression analysis showed that serum estradiol levels were associated with incident delirium even after adjusting for multiple confounding covariates, including cortisol levels (OR: 1.93; 95% CI: 1.28-2.92).

Conclusions: Elderly women with high serum estradiol levels at hospital admission had an increased risk for incident delirium. Serum estradiol may be a biomarker for increased risk of delirium.