title: Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio.
abstract: OBJECTIVE
  Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients.
  
  
  METHODS
  A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted.
  
  
  RESULTS
  Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR.
  
  
  CONCLUSIONS
  Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch.
authors.affiliation: Hospital Clinic IDIBAPS, University of Barcelona, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Martínez
authors.affiliation: Hospital Universitari Vall d'Hebron, Infectious Diseases Division, Universitat Autonoma de Barcelona, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Ribera
authors.affiliation: IrsiCaixa Foundation, Institut Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Clotet
authors.affiliation: Instituto de Investigación Biomédica del Hospital Clínico San Carlos, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Estrada
authors.affiliation: Hospital Universitario de la Princesa, Instituto de Investigación Princesa, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sanz
authors.affiliation: Infectious Diseases/HIV Unit, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Berenguer
authors.affiliation: Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Rubio
authors.affiliation: Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Pulido
authors.affiliation: Hospital de Mataró, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Larrousse
authors.affiliation: Hospital Universitari Vall d'Hebron, Infectious Diseases Division, Universitat Autonoma de Barcelona, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Curran
authors.affiliation: IrsiCaixa Foundation, Institut Germans Trias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Negredo
authors.affiliation: Gilead Sciences Inc., Foster City, CA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Arterburn
authors.affiliation: Gilead Sciences SL, Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Ferrer
authors.affiliation: Gilead Sciences SL, Madrid, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Álvarez
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D050218:Body Fat Distribution; D004338:Drug Combinations; D057915:Drug Substitution; D000068679:Emtricitabine / Q000627:therapeutic use*; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D000068698:Tenofovir / Q000627:therapeutic use*; D015215:Zidovudine / Q000627:therapeutic use*
chemical_list: D019380:Anti-HIV Agents; D004338:Drug Combinations; C109078:lamivudine, zidovudine drug combination; D019259:Lamivudine; D015215:Zidovudine; D000068698:Tenofovir; D000068679:Emtricitabine
keywords: emtricitabine; fat mass ratio; lipoatrophy; tenofovir; zidovudine