Novel imaging modalities for the comparison of bone microarchitecture among HIV+ patients with and without fractures: a pilot study

Background: HIV-infected adults have increased fracture risk. Objectives: To generate pilot data comparing bone density, structure, and strength between HIV-infected adults with and without a prior fracture. Methods: Adults with and without a prior fracture after their HIV diagnosis were matched 1:1 based on age, sex, race, and smoking history. Participants underwent dual-energy X-ray absorptiometry (DXA), trabecular bone score (TBS), hip structural analyses (HSA), vertebral fracture assessment (VFA), high-resolution peripheral quantitative tomography (HR-pQCT) and measurement of bone turnover markers. Results were compared between cases and controls, with differences expressed as percentages of control group values. Results: 23 pairs were included. On DXA, cases had lower areal bone mineral density (aBMD) at the total hip (median difference in T-score −0.25, p = 0.04), but not the lumbar spine (median difference in T-score 0.10, p = 0.68). Cases had greater abnormalities in HSA and most HR-pQCT and HSA measures, by up to 15%. VFA revealed two subclinical fractures among cases but none among controls. TBS, CTX, and P1NP levels were similar between groups, with differences of 1.9% (p = 0.90), 9.7% (p = 0.55), and 10.0% (p = 0.24), respectively. For each parameter, we report the median and interquartile range for the absolute and relative difference between cases and controls, the correlation between cases and controls, and our recruitment rates, to inform the design of future studies. Conclusions: These pilot data suggest potential differences in bone structure, estimated bone strength, and asymptomatic vertebral fractures among HIV-infected adults with and without fracture, warranting further study as markers of fracture risk in HIV.