Acute manic episode is associated with an increased risk of lower limb edema.

Objective: Lower limb edema (LLE) was suggested to be associated with the use of psychotropic drugs among patients suffering from severe mental illnesses; however no direct mechanism was found. Therefore, we examined the association between the occurrence of LLE and acute untreated episode leading to hospitalization.

Methods: A retrospective cross-sectional study was conducted using medical charts of 2529 patients admitted to Geha Mental Health Center between 2002 and 2012. Incident cases of LLE, demographic and clinical data were retrieved. Admission clinical status was modeled as three non-overlapping groups of patients: (i) Patients with a non-affective psychosis (NAP) episode (n = 1563), (ii) patients with a manic episode (n = 366), and (iii) patients with a depressive episode (n = 600). We performed a logistic regression analysis with LLE as the dependent variable controlling for the demographic and clinical variables that may be associated with LLE.

Results: LLE was diagnosed in 3.8% (n = 95) of the study population. The rate of LLE was 3-fold higher (χ(2) = 51.9, df = 2, p<0.001) in patients admitted with a manic episode (n = 38; 10.4%) compared to patients admitted with a NAP episode (n = 41; 2.6%) and patients admitted with a depressive episode (n = 16; 2.7%). Manic episode was associated with an increased risk for LLE compared to depressive episode (OR 8.72, 95% CI: 3.53-21.52, p<0.001) or NAP episode (OR 3.96, 95% CI: 2.16-7.26, p<0.001) after controlling for relevant confounders.

Conclusion: Acute manic episode, leading to hospitalization, is associated with an increased risk of LLE, compared to NAP or depressive episode, suggesting causal relationship between mood and fluid imbalance. Yet, future prospective studies are needed to rule out the contribution of physical agitation and lithium treatment.