Hypomagnesemia and incident delirium in hospitalized older persons.

Background: Altered serum magnesium (Mg) levels in older persons have been hypothesized to have a role in predicting hospitalization and mortality. Hypomagnesemia and delirium are frequent problems in older patients, but no study has evaluated such an association in acute geriatric setting.

Aims: We investigated the impact of hypomagnesemia on the incidence of delirium in an acute geriatric setting.

Methods: This retrospective study was conducted on 209 older hospitalized patients. All subjects underwent a comprehensive geriatric assessment. Mg was measured in serum by routine laboratory methods. The presence of incident delirium was determined by the 4AT screening tool. A logistic regression model was used to assess the association between serum Mg and delirium controlling for multiple covariates.

Results: 209 patients (77.9% women) were included in the study. The mean age of the participants was 85.7 ± 6.50 years (range 65-100). 27 subjects (12.9%) developed delirium during the hospitalization, with no difference between genders. Subjects with delirium had lower serum magnesium levels than those without (1.88 ± 0.34 versus 2.04 ± 0.28; p = 0.009). Delirium risk was significantly higher in patients with lower serum magnesium levels (OR 5.80 95% CI 1.450-23.222; p = 0.013), independent of multiple covariates.

Conclusion: Our data show that low serum Mg level is a good predictor of incident delirium in acute geriatric settings. Present findings have relevant implications for clinical management, highlighting the need for analyzing Mg concentration carefully. Whether Mg supplementation in patients with hypomagnesemia could lead to delirium prevention and/or control needs further investigation.