7th Conference - Abstract 208

Osteopenia in a Randomized, Multicenter Study of Protease Inhibitor (PI) Substitution in Patients with the Lipodystrophy Syndrome and Well-Controlled HIV Viremia

J. HOY*¹, J. HUDSON², M. LAW², D. A. COOPER^{2, and} for the PIILR investigators*. ¹The Alfred Hosp., Melbourne, ²Natl. Ctr. in HIV Epidemiology and Clin. Res.; and ³St. Vincent's Hosp., Sydney, Australia.

Background: Osteopenia has been observed in patients with diabetes, male hypogonadism and inflammatory bowel disease. It has not been studied in HIV-infected patients to date, despite the presence of elevated insulin, low testosterone and elevated cytokine levels in many patients.
Methods: 80 HIV-infected patients with lipodystrophy (defined by total body fat <20% on DEXA scanning) and suppressed viremia (viral load <400 copies/ml) enrolled in the PIILR study. Body composition measurements including determination of regional bone mineral densities (BMD) and T- and Z- scores by DEXA scans were performed at screening, weeks 12 and 24 after randomization to either continue the PI based regimen or switch to a non-PI regimen. Osteopenia was defined as a T-score between -1 and -2.5, and osteoporosis as a T-score less than -2.5.
Results: 21 of 74 patients (28.4%) had evidence of osteopenia at baseline, and a further 7 (9.5%) had osteoporosis. There was no change in the proportion of individuals with osteopenia, over 24 weeks. There was no significant change from baseline in BMD and T-scores for arms, legs, trunk and total scores and no statistically significant differences by treatment group. There was no association between baseline insulin level, CD4 cell count, duration of antiretroviral therapy, duration of PI use and baseline T-scores.
Conclusions: There is a high prevalence of osteopenia and osteoporosis in HIV-infected men with lipodystrophy. Further study into the aetiology of loss of bone mineral density in the HIV population is indicated, in addition to identification of risk factors and appropriate prevention strategies.

Key Words: HIV, lipodystrophy, osteopenia