Increased rates of bone fracture among HIV-infected persons in the HIV Outpatient Study (HOPS) compared with the US general population, 2000-2006

Abstract

Background: Among persons with HIV infection, low bone mineral density is common and has raised concerns about increased risk of fracture.

Methods: We analyzed data from the HIV Outpatient Study (HOPS), an open prospective cohort study of HIV-infected adults who were followed up at 10 US HIV clinics. We assessed rates of first fractures at any anatomic site during the period 2000-2008. We indirectly standardized the rates of fracture in the HOPS to the general population by age and sex, using data from outpatients in the National Hospital Ambulatory Medical Care Survey (NHAMCS-OPD). We examined factors associated with fractures using Cox proportional hazards modeling.

Results: Among 5826 active HOPS patients whose data were analyzed (median baseline age, 40 years; male sex, 79%; white race, 52%; exposure to antiretroviral therapy, 73%), 233 patients had incident fractures (crude annual rates, 59.6-93.5 fractures per 10,000 persons). Age-standardized fracture rates increased from 2000 to 2002 (P = .01) and stabilized thereafter. Among persons aged 25-54 years, both fracture rates and relative proportion of fragility fractures were higher among HOPS patients than among patients in the NHAMCS-OPD. In addition to older age and substance abuse, nadir CD4+ cell count <200 cells/mm(3) (adjusted hazard ratio [aHR], 1.60; 95% confidence interval [CI], 1.11-2.31), hepatitis C infection (aHR, 1.61; 95% CI, 1.13-2.29) and diabetes (aHR, 1.62; 95% CI, 1.00-2.64) were associated with incident fractures.

Conclusions: Age-adjusted fracture rates among HOPS patients were higher than rates in the general US population during the period 2000-2006. Clinicians should regularly assess HIV-infected persons for fracture risk, especially those with low nadir CD4+ cell counts or other established risk factors for fracture.