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.