Impact of hyponatremia on multiple myeloma hospitalizations: A nationwide analysis.

Abstract

e19529 Background: Pseudohyponatremia has been studied to be a common laboratory artifact associated with Multiple Myeloma[MM] due to the paraproteinemia and the fluid shift. But recent studies are emerging with evidence of true hyponatremia in patients with MM usually associated with reduced anion gap. Hyponatremia is also one of the adverse effects with chemotherapy and major comorbidity associated with MM. In this study, we tried to study the effect of hyponatremia on the outcomes of MM. Methods: A retrospective analysis was formulated using the National Inpatient Sample database from 2016-2020. ICD 10 codes were used to find correlation between MM and Hyponatremia. The effects on morbidity, mortality, and secondary outcomes were compared in MM patients with Hyponatremia and without Hyponatremia. Categorical variables were compared using chi-square test, and continuous variables were compared using t-test. Multivariable regression analyses were performed adjusting for demographics, hospital-level characteristics, and relevant comorbidities. These included: Age, gender, race, Charlson Comorbidity Index, chronic kidney disease, congestive heart failure, adrenal insufficiency, polydipsia, hypothyroidism, alcohol use disorder, and various patient and hospital characteristics. Results: A total of 576,869 adults with MM were identified, of which 13.3% were diagnosed with hyponatremia. Mean age was 69 years, and 44 % were females. Patients with hyponatremia had 7.2% in-hospital mortality compared to 4.6% for patients without hyponatremia with an OR 1.61 [p-value 0.00]. Multivariate regression analysis showed that among those with MM, presence of hyponatremia increased the chance of mortality with OR 1.54 [1.43 - 1.65, p- value 0.00]. Hyponatremia also had significant impact on secondary outcomes including cerebral edema with OR 2.28 [1.76 - 2.95, p - value 0.00], AKI with OR 2.02 [1.94 - 2.09, p-value 0.00], Need for ventilator 2.28 [1.76 - 2.95, p-value 0.00] and sepsis 1.74 [1.66-1.81, p-value 0.00]. However there was no statistically significant differences found in venous thromboembolism and altered mental status. Hyponatremia also had an increased length of stay and Total hospital source utilization (Table). Conclusions: Hyponatremia is associated with multiple complications in MM hospitalizations. They even tend to portend worse prognosis as per our results. Further prospective studies are required to prove this association and management strategies should be established to improve outcomes and prevent complications. [Table: see text]