Acute phase response and energy balance in stable human immunodeficiency virus-infected patients: a doubly labeled water study.

We sought to assess possible associations of the acute phase response with energy balance as a cause of malnutrition in uncomplicated HIV-infection. Seven stable HIV-infected patients and 7 control subjects were followed for 2 weeks for blood chemistry, body composition, total and resting energy expenditure (TEE, REE), heart rate, energy intake, and physical activity; 6 patients were investigated for interleukin-2 receptor. TEE, REE, energy intake, and anthropometric data in patients and control subjects were very similar. However, physical activity, total body potassium, and bioimpedance phase angle were decreased (1.41 ± 0.08 vs 1.55 ± 0.9, 152 ± 10 g vs 191 ± 37 g, and 6.4 ± 0.8 degrees vs 7.1 ± 0.5 degrees; each P < .05), and mean heart rate, fibrinogen, and erythrocyte sedimentation rate were increased in HIV-infected patients (84 ± 6 bpm vs 76 ± 8 bpm, 4.3 ± 1.2 g/L vs 2.5 ± 0.4 g/L, and 21 ± 13 mm vs 2 ± 3 mm; P < .05). The deviation between the measured and the predicted REE in the patient group correlated positively with heart rate and serum interleukin-2 receptor concentrations (r = 0.83 and r = 0.91; P < .05). Possible increases in REE caused by an ongoing acute phase response may be counterbalanced by reduced physical activity that results in normal TEE in HIV infection. (J Lab Clin Med 2001;138:94-100)