The effect of severe undernutrition and subsequent refeeding on whole-body metabolism and protein synthesis in human subjects.
BACKGROUND
To determine the consequences of severe undernutrition and refeeding on whole-body metabolism and protein synthesis.


METHODS
Respiratory quotient (RQ), resting energy expenditure (REE), and whole-body protein synthesis (WBPS) were assessed in undernourished patients, with anorexia nervosa (n = 8) or with coexistent disease (n = 17). Results were compared with 17 healthy controls. Six anorexic patients and 13 disease patients consented to study after nutrition support.


RESULTS
Mean body mass index was 12.46 +/- 0.53 kg/m2 in the anorexia patients and 13.81 +/- 0.40 kg/m2 in the disease patients (controls 23.71 +/- 0.72 kg/m2; p < .001). Compared with controls, RQ was similar in anorexia patients (0.85 +/- 0.05 vs 0.90 +/- 0.05) but lower in the disease patients (0.76 +/- 0.03 vs 0.90 +/- 0.05; p = .02). REE was lower in the patients (anorexia 1058 +/- 134.0 kcal/d, disease 1189 +/- 101.4 kcal/d vs 1828 +/- 89.76 kcal/d; p < .001); however, expressed as kcal/kg/d, it was higher (anorexia 32.17 +/- 4.25, disease 31.30 +/- 2.14 vs 25.07 +/- 1.00; p < .05). WBPS was lower in the patients (anorexia 140.9 +/- 10.54 g/d, disease 119.8 +/- 8.57 g/d vs 305.0 +/- 21.64 g/d; p < .001); however, when expressed as g/kg/d, the anorexia patients were similar to controls, whereas the disease patients were lower (3.11 +/- 0.24 vs 4.27 +/- 0.32; p < .05). Refeeding increased RQ in the disease patients (0.84 +/- 0.03 vs 0.76 +/- 0.03; p < .05), and normalized REE (anorexia 27.65 +/- 3.05 kcal/kg/d, disease 28.90 +/- 1.85 kcal/kg/d). WBPS increased in the disease patients (173.6 +/- 16.38 g/d vs 116.5 +/- 10.15 g/d; p < .01).


CONCLUSIONS
Undernutrition is associated with increased REE (kcal/kg/d). Reduction in RQ and protein synthesis (g/kg/d) was evident in those patients with coexistent disease. Refeeding resulted in normalization of RQ, REE (kcal/kg/d), and protein synthesis (g/kg/d).
Winter
T A
TA
Division of Digestive Disease and Nutrition, University of Kentucky, Lexington, Kentucky 40536, USA. winter@uky.edu
O'Keefe
S J
SJ
Callanan
M
M
Marks
T
T
D000704:Analysis of Variance; D000856:Anorexia Nervosa / Q000150:complications / Q000378:metabolism*; D001481:Basal Metabolism; D015992:Body Mass Index; D002245:Carbon Dioxide / Q000378:metabolism; D016022:Case-Control Studies; D002908:Chronic Disease; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D044342:Malnutrition / Q000209:etiology / Q000378:metabolism* / Q000628:therapy*; D018529:Nutritional Support / Q000379:methods*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D012720:Severity of Illness Index
D011506:Proteins; D002245:Carbon Dioxide