Identification of risk factors associated with hyponatremia in psychiatric patients: a case-control study.

Background and aims: Prompt recognition and optimal management of hyponatremia helps the physician devise a better treatment plan to prevent future complications in patients. Hence this study aims to identify the risk factors associated with hyponatremia in psychiatric patients. Methods: A case-control study was conducted among psychiatric inpatients in a tertiary care teaching hospital. Patients admitted from January 2013 to December 2017 were identified using ICD-10 code F01-F99. Patients with serum sodium levels < 135 mmol/L were considered to have hyponatremia and between 135-145 mmol/L as controls. Factors associated with hyponatremia were identified by multiple logistic regression, and the odds ratio (OR) was calculated. Results: Based on the inclusion and exclusion criteria, 264 cases of hyponatremia and 253 matching controls were included in the study. The mean age of patients with hyponatremia was 56.4 ± 16.8 years compared to 39.6 ± 13.9 years in controls, and 65.7% of them were males. Seizure disorder (OR = 3.14, p = 0.047), bipolar disorder (OR = 6.03, p = 0.001), depression (OR = 4.78, p = 0.0005), use of quetiapine (OR = 2.11, p = 0.007) and insulin (OR = 3.53, p = 0.038) were independent risk factors associated with development of hyponatremia. Conclusions: The chances of developing hyponatremia are increased in psychiatric patients with a seizure disorder, bipolar disorder, depression and using quetiapine or insulin. And they should be monitored carefully.