Elevated resting energy expenditure among HIV-seropositive persons receiving highly active antiretroviral therapy

Objectives: To ascertain the relationships between resting energy expenditure (REE), HIV RNA in plasma, and highly active antiretroviral therapy (HAART). Design: Cross-sectional analysis using data of a large cohort study of nutrition in relation to HIV disease. Methods: HIV RNA in plasma, REE, fat-free mass (FFM), and medication regimens were assessed at 530 visits among 372 participants in a cohort study of HIV-seropositive men and women. Results: HIV RNA in plasma was directly correlated with REE. After adjustment for FFM, age, CD4 cell count and HAART use, there was an increase in REE of 90 kJ/day per log(10) copies/ml increase in HIV RNA [95% confidence interval (CI) 16-164; P = 0.02). HAART use had an independent effect on REE. In patients reporting HAART use, adjusted REE was 339 kJ/day higher than in those not reporting HAART use (95% CI 177-501; P = 0.0001). Conclusions: Viral load and HAART appear to exert independent effects on REE. Although HAART may decrease metabolic rate by lowering viral burden, it appears to increase metabolic demands through some mechanism(s) independent of its effect on viral burden. This may result in elevated REE despite control of viral replication. (C) 1999 Lippincott Williams & Wilkins.