The Differential Effects of HIV and HCV on Bone Micro-Architecture and Fracture risk

Abstract

Background

HIV/HCV co-infected subjects have a significantly greater osteoporotic fracture risk than HIV-infected, despite the fact that HIV/HCV co-infection has not been associated with lower bone mineral density (BMD) than HIV or HCV alone. We evaluated if changes in bone microarchitecture , measured by trabecular bone score (TBS) could explain these differences.

Design

We performed a prospective, cross-sectional cohort study of virologically suppressed HIV, untreated HCV, HIV/HCV co-infected and non-infected controls.

Methodology

We enrolled 532 male subjects : 57 HIV/HCV, 174 HIV, 123 HCV and 178 controls. We conducted analysis of covariance comparing BMD and TBS between groups, controlling for age, race, BMI and smoking. We used linear regression to evaluate predictors of BMD and TBS and evaluated the effects of severity of HCV infection and Tenofovir (TDF) use.

Results

Despite both infections being associated with decreased BMD, only HCV, but not HIV was associated with lower TBS score. Also, HIV/HCV co-infected subjects had lower TBS scores than HIV mono-infected, HCV mono-infected and uninfected subjects. Neither the use of TDF, , HCV viremia nor the severity of HCV liver disease were associated with lower TBS.

Conclusions

HCV infection is associated with micro-architectural changes at the lumbar spine as assessed by the low TBS score, suggesting that microstructural abnormalities underlie some of the higher fracture risk in HCV infection. TBS might improve fracture risk prediction in HCV infection.