7th IAS Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2013)


MOPE078 Poster Exhibition

Number of different antiretroviral regimens rather than cumulative exposure to antiretrovirals associated with lower bone mineral density in HIV-positive subjects

Presented by Aoife G. Cotter (Ireland).

A. Cotter1,2, C.A. Sabin3, S. Simelane1, A. Macken1, B. Rogers1, E. Kavanagh4, J.J. Brady5, P.W.G. Mallon1,2, 'Understanding the Pathology of Bone Disease in HIV Infected Subjects' (HIV UPBEAT) Study Group

1University College Dublin, HIV Molecular Research Group, Dublin, Ireland, 2Mater Misericordiae University Hospital, Department of Infectious Diseases, Dublin, Ireland, 3University College London Medical School, Research Department of Infection & Population Health, London, United Kingdom, 4Mater Misericordiae University Hospital, Department of Radiology, Dublin, Ireland, 5Mater Misericordiae University Hospital, Department of Biochemistry, Dublin, Ireland

Background: The greatest changes in bone mineral density (BMD) in HIV occur with initiation/switch in antiretroviral therapy (ART). We aimed to determine associations between ART exposure and BMD. Methods: In a prospective cohort, HIV positive (HIV+) and negative (HIV-) subjects from similar demographic backgrounds provided demographic, clinical, medication/ laboratory data and underwent annual dual xray absorptiometry (DXA) at femoral neck (FN) and lumbar spine (LS). We examined associations between clinical, virological, immunological and treatment parameters and BMD with t-tests, Pearson correlation and multivariable linear regression. Results are mean[SD] unless specified.
Results: Of 474 subjects, the HIV+ group (n=210) was 58% male, 40% African, median (IQR) age and years since HIV diagnosis were 39[33, 46] years and 5(2,8) years respectively with median number of ART regimens 2(1,3) to a maximum of 13. HIV acquisition risk was heterosexual (46.9%), homosexual sex (25.4%), intravenous drug use (IVDU) (18.7%); 89.2% were on ART, with 97.7%, 48.1% and 48.6% on nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside RTI (NNRTI) and protease inhibitors (PI) respectively. In univariate analyses IVDU risk, HIVRNA< 40copies/mL, number of ART regimens and current and cumulative exposure to NRTI-, PI-classes and individual ART (tenofovir, stavudine, atazanavir, fosamprenavir and ritonavir) were all significantly associated with lower FNBMD (all P< 0.05). After adjustment for age, gender, ethnicity and BMI, neither IDVU risk, current nor cumulative exposure to any ART class or individual agent remained independently associated with lower FNBMD. However HIVRNA< 40copies/mL (-0.053 g/cm2, P< 0.0001) and a greater number of ART regimens (-0.011g/cm2, P =0.04) remained independently associated with lower FNBMD in these adjusted analyses. The influence of number of ART regimens on FNBMD was not appreciably altered by further adjustment for years since HIV diagnosis (-0.013 g/cm2, P=0.04) or total cumulative exposure to ART (-0.013, P =0.05). Similar findings were observed at LSBMD, although IVDU risk remained significantly associated with lower LSBMD.
Conclusion: Number of ART regimens rather than current or cumulative exposure to ART, drug classes or individual drugs was associated with lower BMD, suggesting that multiple ART switches rather than total ART exposure may predict lower BMD in HIV+ subjects.

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