icon-folder.gif   Conference Reports for NATAP  
  4th Intl Lipodystrophy Workshop
San Diego at Coronado Beach, Sept 22-25, 2002
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Effect of d4T and AZT on Leg Fat Loss
  Abstract title: "Effect of d4T, AZT and HIV protease inhibitor therapy on subcutaneous leg fat wasting in HIV-infected males - a longitudinal study"
Reported by Jules Levin
In this study David Nolan (abstract 28) and Australian researchers evaluated the effects of HIV drugs, particularly d4T vs AZT, on leg fat wasting in white male patients on HAART. The overall aim of Nolan was to look at fat loss as a process that occurs over time (longitudinally) and to try and understand the process rather than just looking at fat loss as an endpoint that occurs.
Patients in this study were treatment-naive so they were starting a d4T or AZT based regimen for the first time. If a patient changed therapy they were eliminated from the study. The patients receiving AZT or d4T appeared somwehat comparable in terms of baseline characteristics: age 40, CD4 count 320-355, AIDS 4/24 in d4T arm - 3/25 in AZT group, 24/24 on AZT were also on 3TC, 18/25 in d4T group were on 3TC, 18/24 on d4T were on PI therapy, 16/25 on d4T were on PI therapy as opposed to NNRTI. All patients had on average 3 DEXA scans while on HAART, patients had between 2-6 DEXAs. There was a significant difference in BMI (body mass index) between the two groups: BMI was 25.3 in AZT patients vs 23.3 in d4T patients (p=0.05). So d4T patients had a little less body mass.
On average, the patients had upper-normal BMI (24 kg), weight of 172 lbs, an were 5 ft 11 inches, and age 40. Nolan reported that before starting HAART therapy both d4T and AZT patients averaged 22% leg fat. After following patients for 36 months Nolan reported that the average leg fat was 17.5% in the AZT patients and 11% in the d4T patients. There wasnąt enough statistical power to extend the evaluation beyond 36 months but the trends appeared to be similar following 36 months. There was no significant trend in average BMI over the study course in the overall study patient group or in comparison between D4T and AZT groups. Nolan reported that having older age and having AIDS before HAART could be a contributing factor in contributing to fat loss but the dominant factor in this study was whether you were on d4T or AZT.
Nolan said that proportionality of regional versus overall body composition (% leg fat/BMI) provides a measure that adjusts for individual variation in baseline body composition. Similar findings were obtained in this study for the ratios of leg fat weight to BMI, as mentioned above, and to whole body weight. And Nolan concluded that the choice of AZT or d4T is the significant determinant of long-term trends in peripheral fat wasting in this study, irrespective of concurrent PI or NNRTI therapy. In other words, they did not see a difference in fat loss in the leg whether a patient was on a NNRTI or PI. But when I asked him how this fits with their findings reported previously that combining a PI with a nukes has a synergy in contributing to additional fat loss than just being on nukes, he said that this study was not powered enough to see if there was a difference between being on a PI or NNRTI.