HIV and Hepatitis.com Coverage of the
14th Annual Conference on Retroviruses
and Opportunistic Infections (14th CROI)
February 25 - 28, 2007, Los Angeles, CA
No Significant Body Composition Differences between Patients Treated with Atazanavir vs Atazanavir/ritonavir

Prior studies have demonstrated that metabolic changes in antiretroviral-naive patients treated with atazanavir (Reyataz) are similar to those seen with efavirenz (Sustiva)-based regimens. However, there are fewer data on the effects on body composition when ritonavir (Norvir) is added to atazanavir.

In the current study, presented at the 14th Conference on Retroviruses and Opportunistic Infections last month in Los Angeles, 200 treatment-naive HIV patients were randomly assigned to initiate therapy with 400 mg atazanavir or 300/100 mg atazanavir/ritonavir once daily, each in combination with once-daily d4T (stavudine; Zerit) and 3TC (lamivudine; Epivir).

The following parameters were assessed at baseline, week 24 and week 28:

  • Body composition was evaluated using computed tomography and DEXA imaging;

  • Lipodystrophy case definition scores were recorded;

  • Body mass index (BMI) and hip/waist measurements were assessed.

Results

  • All participants had comparable mean weight changes at 48 weeks from baseline (atazanavir 5%; atazanavir/ritonavir 6%).

  • BMI and waist circumference changes were comparable between the 2 regimens.

  • Minimal changes in waist‑to‑hip ratio were observed.

  • No significant differences between regimens were noted in body composition parameters.

  • Rates of lipodystrophy (body shape changes) and lipohypertrophy (fat accumulation) were similar.

Body Composition Changes through 48 Weeks

Atanazir 400 mg

Atazanavir/ritonavir 300/100 mg

Baseline

48 weeks

% change

Baseline

48 weeks

% change

DEXA (n)

104

89

89

93

72

72

Trunk fat (kg) ±SE

9.1 ±0.59

10.2 ±0.56

15%**

8.9 ±0.59

9.2 ±0.57

12%*

Limb fat (kg) ±SE

7.6 ±0.58

7.6 ±0.58

-3%

7.7±0.53

7.5±0.57

2%

Computed tomography (n)

99

85

83

84

68

65

Visceral adipose tissue (cm2) ±SE

85.4 ±4.8

116.4 ± 6.58

34%***

82.7 ±5.24

105.6 ±7.91

27%***

Subcutaneous adipose tissue (cm2) ±SE

200.6 ±14.88

218.4 ±15.41

11%*

187.8 ±13.98

197.3 ±15.56

13%*

* Percent changes are computed on the log scale p <0.05(*), p <0.001 (**), p < 0.0001(**)


Conclusion

Based on these findings, the investigators concluded that there were no clinically significant differences in body composition between atazanavir and atazanavir/ritonavir in these patients receiving d4T-containing regimens over the 48 week course of the study.

Pharma Res Inst, Bristol-Myers Squibb, Wallingford, CT, US and 2Pharma Res Inst, Bristol-Myers Squibb, Princeton, NJ.

Link to poster

Link to study abstract

03/20/07 

Reference
D McGrath, D Frederick, V Wirtz, and others.. Body Composition Changes in ART-naive Subjects Treated with Atazanavir or Atazanavir/Ritonavir-based Once-daily HAART: 48-Week Computed Tomography and DEXA Data. 14th Conference on Retroviruses and Opportunistic Infections. Los Angeles, CA. February 25-28, 2007. Abstract 804 (poster).











































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