Peripheral and central fat changes in subjects randomized to abacavir-lamivudine or tenofovir-emtricitabine with atazanavir-ritonavir or efavirenz: ACTG Study A5224s

Clin Infect Dis. 2011 Jul 15;53(2):185-96. doi: 10.1093/cid/cir324.

Abstract

Background: We compare the effect of 4 different antiretroviral regimens on limb and visceral fat.

Methods: A5224s was a substudy of A5202, a trial of human immunodeficiency virus type 1 (HIV-1)-infected, treatment-naive subjects randomized to blinded abacavir-lamivudine (ABC-3TC) or tenofovir DF-emtricitabine (TDF-FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV-r). The primary endpoint was the presence of lipoatrophy (≥ 10% loss of limb fat) at week 96 by intent-to-treat (ITT) analysis. Secondary endpoints included changes in limb and visceral fat. Statistical tests included linear regression, binomial, two-sample t test, and Fisher's exact test.

Results: A5224s enrolled 269 subjects; 85% were male, and 47% were white non-Hispanic. The subjects had a median baseline HIV-1 RNA level of 4.6 log(10) copies/mL, a median age of 38 years, a median CD4+ cell count of 233 cells/μL, median limb fat of 7.4 kg, median visceral adipose tissue (VAT) of 84.1 cm(2), and VAT: total adipose tissue (TAT) ratio of 0.31. At week 96, estimated prevalence of lipoatrophy (upper 95% confidence interval [CI]) was 18% (25%) for ABC-3TC and 15% (22%) for TDF-FTC (P = .70); this was not significantly less than the hypothesized 15% for both (P ≥ .55 for both). The secondary as-treated (AT) analysis showed similar results. At week 96, the estimated mean percentage change from baseline in VAT was higher for the ATV-r group than for the EFV group (26.6% vs 12.4%; P = .090 in ITT analysis and 30.0% vs 14.5%; P = .10 in AT analysis); however, the percentage change in VAT:TAT was similar by ITT and AT analysis (P ≥ .60 for both). Results were similar for absolute changes in VAT and VAT:TAT.

Conclusions: ABC-3TC- and TDF-FTC-based regimens increased limb and visceral fat at week 96, with a similar prevalence of lipoatrophy. Compared to the EFV group, subjects assigned to ATV-r had a trend towards higher mean percentage increase in VAT.

Clinical trials registration: NCT00118898.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-HIV Agents / administration & dosage*
  • Anti-HIV Agents / adverse effects*
  • Antiretroviral Therapy, Highly Active / adverse effects*
  • Antiretroviral Therapy, Highly Active / methods*
  • Body Fat Distribution
  • Female
  • HIV Infections / drug therapy*
  • HIV Infections / virology
  • HIV-1 / isolation & purification
  • HIV-Associated Lipodystrophy Syndrome / chemically induced*
  • Humans
  • Male
  • Middle Aged

Substances

  • Anti-HIV Agents

Associated data

  • ClinicalTrials.gov/NCT00118898