Effect of malabsorption on nutritional status and resting energy expenditure in HIV-infected patients

To assess the influence of malabsorption on nutritional status and energy expenditure in patients at different stages of HIV infection.

Fifty HIV patients were classified into three groups: Group 1, HIV asymptomatic patients (n=17); Group 2, AIDS without opportunistic infection (n=16); Group 3, AIDS patients with active infection (n=17). Clinically-healthy subjects (n=19) were used as controls. Parameters measured were: anthropometry, body composition by tetrapolar bioelectrical impedance; resting energy expenditure (REE) by open-circuit indirect calorimetry; malabsoption by D-xylose absorption and triolein breath tests.

Malabsorption (defined as abnormality of xylose and/or fat absorption test) was found in 34 (68%) of patients: 9 (53%) Group 1; 11 (69%) Group 2; 14 (82%) Group 3. Twenty-seven (54%) had sugar malabsorption and 21 (42%) fat malabsorption. A significant relationship was observed between malabsorption and weight loss. REE measured was significantly lower in malabsorptive patients than in non-malabsorptive patients and controls (6006.3+/-846.5 versus 6443.4 + 985.5 versus 6802.1+/-862.7 kJ/day, respectively; P < 0.05). The REE adjusted for fat-free mass was lower in malabsorptive than in non-malabsorptive patients and slightly higher than in controls, although the differences were not statistically significant.

The results suggest that malabsorption is a frequent feature in HIV infection and is related to the HIV-related weight loss. Hypermetabolism is not a constant phenomenon in HIV infection since, in the presence of malabsorption, our patients show an appropriate metabolic response with a compensatory decrease in REE.