Impact of Protein Energy Malnutrition on Hospitalized Patients with Multiple Myeloma: A United States Population-Based Cohort Study

Background Multiple myeloma poses a significant burden to the society and the healthcare system. With newer advances in therapeutics and prolonged survival, these patients are predisposed to multiple co-morbidities, including cancer-related cachexia, systemic inflammation, and adverse effects of therapy, often leading to varying degrees of protein-energy malnutrition (PEM). PEM can further complicate the clinical picture, leading to an inability to tolerate therapy & propagation of this vicious cycle. Thus, the impact of PEM on outcomes among patients with multiple myeloma needs further exploration. Methods We utilized the 2020 National Inpatient Sample (NIS) Database to conduct this retrospective cohort study. We identified patients with multiple myeloma and PEM using appropriate ICD-10 diagnostic codes. We stratified patients with multiple myeloma based on the presence or absence of PEM. A survey multivariable logistic and linear regression analysis was used to calculate adjusted odds ratios (ORs) for the primary and secondary outcomes. A p-value of <0.05 was considered statistically significant. The aim of this study was to investigate the impact of PEM on in-hospital mortality, hospital length of stay (LOS), and total hospitalization charges among hospitalized patients with multiple myeloma. Results We identified a total of 19025 hospitalized patients with multiple myeloma, of which 12.50% (2380/19025) had co-morbid PEM. The overall in-hospital mortality among patients with multiple myeloma was 4.33% (825/19025). Among those with concomitant PEM, the mortality rate was significantly higher at 9.24% (220/2380, p<0.001). Utilizing a stepwise survey multivariable logistic regression model that adjusted for patient and hospital level confounders, PEM was found to be an independent predictor of increased in-hospital mortality (adjusted OR 2.53; 95% (confidence interval [CI] 1.70-3.76; p<0.001), longer LOS (coefficient 3.78; CI 2.29-5.27; p<0.001), higher total hospitalization charge ($59042; CI $28467-$89617; p<0.001), and increased need for mechanical ventilation (adjusted OR 2.92; CI 1.78-4.79; p<0.001). Conclusion Our analysis demonstrated that PEM was widely prevalent in patients with multiple myeloma. It was associated with worse outcomes, including significantly increased in-hospital mortality, longer LOS, total cost of healthcare utilization, as well as increased need for mechanical ventilation. Efforts should be made to promote nutritional assessment and screening mechanisms to include early nutritional support as indicated. Prospective studies with larger sample sizes are warranted to better understand these associations.