10th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV 6-8 November 2008, London, UK

ASSOCIATION BETWEEN PERIPHERAL LIPOATROPHY AND BONE DEMINERALIZATION IN TREATED HIV-POSITIVE MALES

Antiviral Therapy 2008; 13(Suppl. 4):A33 (abstract no. P-15)

J Falutz and K Rosenthall
McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, Canada

INTRODUCTION: Bone demineralization is increasingly recognized as an important component of the metabolic complications affecting HIV-positive patients. In the general population, multiple factors influence bone mineral density (BMD) including both regional lean and fat mass. In treated HIV patients, body composition changes still include peripheral lipoatrophy, relative stability of lean mass and variable changes in central fat mass. We investigated factors associated with regional bone demineralization in HIV-positive males.

METHODS: A cohort of treated, clinically stable males who underwent DXA scans between 2001 and 2007 were characterized with regards to clinical (highly active antiretroviral therapy [HAART] usage, CD4s, HIV viral load [V_L], body mass index, cigarette use and serum testosterone levels), metabolic (fasting lipid and glucose homeostasis), DXA- derived regional body composition (limb fat mass/total body fat mass ratio [%L/TBFM]) and DXA-derived BMD parameters (femoral neck [FN], total hip [TH] and lumbosacral [LS] spine T-scores). Differences between medians of variables were compared using the Mann–Whitney U test in patients grouped below and above the median value for the %L/TBFM. Differences between proportions were determined by Χ² analysis.

RESULTS: Data was available on 129 males (median age 47 [46–49], CD4s 438 [357–488], 68% with undetectable V_L). Antiretroviral use at the time of DXA acquisition revealed that 34% were on AZT, 40% on D4T, 13% on TDF, 64% on PI HAART and 33% on NNRTI HAART. The median L/TBFM ratio was 36%. Median T-score at the FN in patients with %L/TBFM <36% was -2.08 (-2.4– -1.8) versus -1.84 (-2.3–-1.2) in patients with %L/TBFM >36% (P=0.03). Median T-score at the TH in patients with %L/TBFM <36% was -1.81(-2.1–-1.4) versus -1.56 (-2.0–-0.9) in patients with %L/TBFM >36% (P=0.11). There was no difference in T-scores at the LS spine in patients with %L/TBFM < or >36%. Comparing patients with %L/TBFM < or >36%, there were more patients with osteopenia and osteoporosis at the FN (87% versus 71%, P=0.048) and at the TH (77% versus 62%, P=0.049), but not at the LS spine. The limb lean mass did not change significantly for changes in limb fat mass. There were no differences in patients with %L/TBFM < or >36% with regards to age, body mass index, cigarette use, CD4s, V_L, HOMA or testosterone. Antiretroviral use was similar in both groups except more patients with %L/TBFM <36% were on D4T and more patients with %L/TBFM >36% were on AZT.

CONCLUSION: Progressive loss of peripheral fat mass, unrelated to loss of lean mass, is associated with decreasing BMD in the hip region but not at the LS spine. This LA-associated bone demineralization may contribute to increasing hip-related morbidity in treated patients, especially as they age. Both total body and regional BMD assessment should be considered and efforts to prevent and treat peripheral LA instituted where possible.

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2008-11-06
P-15

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