The Impact of Nutritional Therapy on Resting Energy Expenditure in Malnourished Older Hospitalized Patients

Abstract

Background and aims: Little is known about the effect of nutritional therapy on resting energy expenditure (REE) in malnourished older hospitalized patients. We sought to evaluate longitudinal changes in REE during nutritional therapy and to examine the different factors associated with changes in REE among these patients.Methods: Twenty-three malnourished older patients (age range 67–93, 65% women) participated in this prospective longitudinal observational study. Malnutrition was defined as Mini Nutritional Assessment Short Form (MNA-SF) < 8. REE was measured by using indirect calorimetry on hospital admission and at discharge. Body composition (i.e. fat free mass (FFM)) was assessed by bioelectrical impedance analysis. The Parker mobility score was performed to evaluate the patient's mobility. Nutritional support (i.e. high protein and/or high calorie oral nutritional supplements) was provided to all malnourished patients during hospitalization.Results: All patients were malnourished with a median MNA-SF score of 6. The median time between two REE measurements was 13 days (interquartile range: 11–15). On admission, REE was significantly lower in patients with lower FFM (P = 0.043) and decreased along with the degree of malnutrition (P = 0.008). REE (+ 212.6 kcal, P = 0.010) and REE/FFM (+ 5.6 kcal/kg, P = 0.021) increased significantly during hospitalization. In a multiple regression analysis, age, gender and BMI followed by MNA-SF score and mobility were the major independent risk factors of changes in REE.Conclusion: Low REE in malnourished older patients increased to normal after 2 weeks of nutritional treatment.