Increased Fracture Incidence in Middle-Aged HIV-Infected and HIV-Uninfected Women: Updated Results From the Women's Interagency HIV Study

Abstract

Background: We previously reported that fracture incidence rates did not differ by HIV status among predominantly premenopausal Women's Interagency HIV Study participants. We now conduct a follow-up study with 5 additional observation years to further characterize fracture risk associated with HIV infection in women as they age.

Methods: We measured time to first new fracture at any site in 2375 (1713 HIV-infected and 662 HIV-uninfected) Women's Interagency HIV Study participants, with median 10-year follow-up. Fractures were self-reported semiannually. Proportional hazards models assessed predictors of incident fracture.

Results: At index visit, HIV-infected women were older [median age of 40 years (IQR: 34-46) vs. 35 (27-43), P < 0.0001] and more likely to be postmenopausal, hepatitis C virus infected, and weigh less than HIV-uninfected women. Among HIV-infected women, mean CD4 count was 480 cells per microliter and 63% were taking highly active antiretroviral therapy. Unadjusted incidence rates of any fracture were higher in HIV-infected than in HIV-uninfected women [2.19/100 person-years (py) vs. 1.54/100 py, P = 0.002]. In multivariate models, HIV status, older age, white (vs. black) race, prior fracture, history of cocaine use, and history of injection drug use were significant predictors of incident fracture. Among HIV-infected women, age, white race, prior fracture, smoking, and prior AIDS were predictors of new fracture.

Conclusions: Middle-aged HIV-infected women had a higher adjusted fracture rate than HIV-uninfected women. Cocaine use and injection drug use were also associated with a greater risk of incident fracture. Further research is needed to understand whether the risk of fracture associated with cocaine use relates to increased rate of falls or direct effects on bone metabolism.

Figure 1

(a). Incidence of new fracture (fragility or non-fragility) at any site, unadjusted in HIV-infected (dashed line) and uninfected (solid line) women (P=0.002). (b). Incidence of new fracture (fragility or non-fragility) at any site adjusted for age, race, fracture before index, cocaine use (ever) and injection drug use (ever) in HIV-infected (dashed line) and uninfected (solid line) women (P=0.04).