Energy expenditure of acutely ill hospitalised patients

OBJECTIVE To measure energy expenditure of acutely ill elderly patients in hospital and following discharge in the community. DESIGN Sixty-three consecutive hospitalised acutely ill elderly patients were recruited. Eight patients were studied to assess the reliability of the Delta Tract Machine as a measure of energy expenditure; 35 patients had their energy expenditure studied in hospital on two occasions and 20 patients had their energy expenditure measured in hospital and at 6 weeks in the community RESULTS Men had higher basal energy expenditure (BMR) values compared to women however the difference was not statistically significant [Men, mean (SD) 1405 (321) Kcal, women 1238 (322) kcal; mean difference (95% CI) 166 kcal (-17 to 531), p = 0.075]. After adjusting for age, gender and body mass index both medication and C-reactive protein (CRP), concentrations showed significant correlation with measured energy expenditure in hospital, (r = -0.36, "p < 0.05"; r = -0.29, "p < 0.05" respectively). However, in a multivariate analysis for all 63 subjects combined CRP explained most of the variance in BMR in hospital. The Harris Benedict equation predicted within +/- 10% measured BMR in only 47% of individuals in hospital. CONCLUSION Tissue inflammation and medications were associated with change in measured energy expenditure in acutely ill patients.