Immune Function Is Impaired With a Mini Nutritional Assessment Score Indicative of Malnutrition in Nursing Home Elders With Pressure Ulcers

Abstract

Background: Malnutrition is prevalent in elders with pressure ulcers and is associated with increased morbidity and mortality. This study compared nutritional status, assessed by the Mini Nutrition Assessment (MNA), to immune function in nursing home elders with pressure ulcers. Methods: Nutritional status was assessed in nursing home residents (>65 years) with a stage II or more severe pressure ulcer. Subjects were classified as well nourished, at risk of malnutrition, or malnourished according to MNA score. Blood was drawn to assess whole blood mitogen-induced lymphocyte proliferation and neutrophil respiratory burst. Delayed-type hypersensitivity to 3 antigens was measured. MNA status was compared with immune parameters using the Kruskall-Wallis test. Results: Of the 24 subjects (23 men, 1 woman) who completed the study protocol, only 4 (17%) were classified as well nourished, whereas 7 (29%) were at risk and 13 (54%) were malnourished according to MNA score. Whole blood lymphocyte proliferation was significantly lower in the malnourished vs at risk subjects with both pokeweed (median [25^th,75^th percentile], 0.6 [0.3, 0.9] vs 1.8 [1.2, 2.1] disintegrations per minute [dpm]/cell, p< .05); and concanavalin A (1.7 [0.9, 2.0] vs 2.8 [2.6, 3.9] dpm/cell, p < .05) mitogens. Neutrophil respiratory burst normalized to a young control was significantly lower in malnourished subjects vs well-nourished subjects (0.8 [0.5, 0.9] vs 1.4 [1.0, 1.7], p < .05). Total induration to 3 skin-test antigens was 13.4± 4.6, 3.5 ± 2.6, and 3.8 ± 1.8 (mean ± SEM) for well-nourished, at risk, and malnourished, respectively (p = .059). Conclusions: Immune function is impaired with an MNA score indicative of malnutrition in nursing home elders with pressure ulcers.