Risk Factors Associated with Avascular Necrosis in HIV-Infected Patients in the New Antiretroviral Therapy Era

Abstract

Background. Avascular necrosis (AVN) has been shown to have a higher prevalence in the HIV population. This is partly due to high prevalence of already established risk factors such as hyperlipidemia, alcohol abuse, and steroid use, as well as the use of protease inhibitors. There have not been any studies looking at risk factors for avascular necrosis in the more recent antiretroviral therapy era. Methods. We conducted a case‐control study among HIV‐infected individuals who receive care at the Partnership Comprehensive Care Practice at Drexel University, Philadelphia, Pennsylvania. Cases were retrospectively identified, with AVN defined by surgical pathology or imaging. For each case, 1 control patient was randomly selected who showed no evidence of AVN and was matched for gender and age. Chi‐square, Fisher exact, and unpaired T‐tests were used to compare AVN and control groups on dichotomous or numeric variables. A logistic regression model was used to evaluate the effect of hypothesized risk factors. Results. We included 33 cases in our study from 2003 through 2015; 76% were male, 65% were African American, and the median age was 46 ± 7 years. Using logistic regression analysis of the possible risk factors we found an odds ratio of 7 for detectable viral load and AVN (P =.003). We did not find an association between steroid use or protease inhibitor and AVN. Conclusion. A detectable HIV load seems to be an independent risk factor for AVN. In contrast to prior case‐control studies, our study did not find an association between protease inhibitor use and avascular necrosis. It is possible that newer protease inhibitors are not associated with avascular necrosis.