title: Body fat changes among antiretroviral-naive patients on PI- and NNRTI-based HAART in the Swiss HIV cohort study.
abstract: BACKGROUND
  Body fat changes are common in patients with HIV. For patients on protease inhibitor (PI)-based highly active antiretroviral therapy (HAART), these changes have been associated with increasing exposure to therapy in general and to stavudine in particular. Our objective is to show whether such associations are more or less likely for patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based HAART.
  
  
  METHODS
  We included all antiretroviral-naive patients in the Swiss HIV Cohort Study starting HAART after April 2000 who had had body weight, CD4 cell count and plasma HIV RNA measured between 6 months before and 3 months after starting HAART, and at least one assessment of body fat changes after starting HAART. At visits scheduled every 6 months, fat loss or fat gain is reported by agreement between patient and physician. We estimate the association between reported body fat changes and both time on therapy and time on stavudine, using conditional logistical regression.
  
  
  RESULTS
  Body fat changes were reported for 85 (9%) out of 925 patients at their first assessment; a further 165 had only one assessment. Of the remaining 675 patients, body fat changes were reported for 156 patients at a rate of 13.2 changes per 100 patient-years. Body fat changes are more likely with increasing age [odds ratio (OR) 1.18 (1.00-1.38) per 10 years], with increasing BMI [OR 1.06 (1.01-1.11)] and in those with a lower baseline CD4 cell count [OR 0.91 (0.83-1.01) per 100 cells/microl]. There is only weak evidence that body fat changes are more likely with increasing time on HAART [OR 1.16 (0.93-1.46)]. After adjusting for time on HAART, fat loss is more likely with increasing stavudine use [OR 1.70 (1.34-2.15)]. There is no evidence of an association between reported fat changes and time on NNRTI therapy relative to PI therapy in those patients who used either one therapy or the other [OR 0.98 (0.56-1.63)].
  
  
  CONCLUSIONS
  Fat loss is more likely to be reported with increasing exposure to stavudine. We find no evidence of major differences between PI and NNRTI therapy in the risk of reported body fat changes.
authors.affiliation: Institut für klinische Epidemiologie, Universitätsspital Basel, Basel, Switzerland. jyoung@uhbs.ch
authors.forename: Jim
authors.initials: J
authors.lastname: Young
authors.forename: Martin
authors.initials: M
authors.lastname: Rickenbach
authors.forename: Rainer
authors.initials: R
authors.lastname: Weber
authors.forename: Hansjakob
authors.initials: H
authors.lastname: Furrer
authors.forename: Enos
authors.initials: E
authors.lastname: Bernasconi
authors.forename: Bernard
authors.initials: B
authors.lastname: Hirschel
authors.forename: Philip E
authors.initials: PE
authors.lastname: Tarr
authors.forename: Pietro
authors.initials: P
authors.lastname: Vernazza
authors.forename: Manuel
authors.initials: M
authors.lastname: Battegay
authors.forename: Heiner C
authors.initials: HC
authors.lastname: Bucher
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000473:pathology*; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000473:pathology*; D017320:HIV Protease Inhibitors / Q000009:adverse effects*; D039682:HIV-Associated Lipodystrophy Syndrome / Q000209:etiology / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects*; D012307:Risk Factors; D018119:Stavudine / Q000009:adverse effects; D013557:Switzerland
chemical_list: D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors; D018119:Stavudine