Obesity and malnutrition in critically ill patients with acute myeloid leukemia: prevalence and impact on mortality

Objectives: Obese patients have an increased risk of developing acute myeloid leukemia (AML), which in turn predisposes to malnutrition. Obesity has been associated with improved survival in critically ill patients (obesity paradox), but this effect seems to disappear when adjusting for malnutrition. How obesity and malnutrition interplay to affect mortality in critically ill patients with AML has not been addressed and was the objective of this study. Methods: This was a retrospective chart review of adult patients with AML who were admitted to the medical intensive care unit and had a nutrition consultation between 2011 and 2018. Demographic characteristics, comorbidities, severity scores, and laboratory parameters, as well as data on vital organ support, hospital mortality, and long-term survival were collected. Obesity was defined by a body mass index of ≥30 kg/m² and malnutrition per the American Society for Parenteral and Enteral Nutrition criteria. Patients were compared based on nutrition and weight status, and hospital and long-term mortality were analyzed with logistic regression and Kaplan-Meier curves. Results: We included 145 patients (57% obese, 30% malnourished) in the study. As time from AML diagnosis elapsed, obesity was less frequent and malnutrition more prevalent, with 25% of obese patients also presenting with malnutrition. Hospital mortality was 40% and associated with malnutrition in nonobese patients (odds ratio: 5.1; 95% confidence interval, 1.3–21.8; P = 0.02) and sequential organ failure assessment severity score (odds ratio: 1.5; 95% confidence interval, 1.3–1.7; P < 0.0001). Sensitivity analyses confirmed the association between malnutrition, but not obesity, and hospital mortality. Obese malnourished patients had lower long-term survival, but this was not significant (P = 0.25). Conclusions: Critically ill patients with AML have a high prevalence of malnutrition and obesity, which are sometimes associated. Malnutrition, but not obesity, was associated with hospital mortality.