There is a growing evidence of the association between HIV infection and fracture risk. Independently of its cause (antiretroviral therapy (ART) or HIV), what remains most important is a prompt diagnosis. Although densitometry is the gold standard, sometimes this technique is not as accurate as necessary in clinical practice. A new validated tool for early and more accurate diagnosis is presented.
In a HIV group of patients, we analyzed the bone properties by microindentation, studying bone strength in vivo in <5 min. Its results are comparable and reproducible. Two groups of patients were included: HIV+ (with and without ART), and controls without HIV and no bone disease. ART naïve patients had at least 5 years of HIV diagnosis. Bone material strength (BMS) was measured with osteoprobe applying a 20 N force on the anterior tibia. Age and gender-adjusted ANOVA was used for comparisons.
Results: 23 HIV patients (nine on ART and 14 without) and 43 controls were included. Age (42+9.9 vs 69+13.4) and gender (14 men and nine women vs four men and 39 women) for HIV+ and controls respectively. After adjusting by age and gender, HIV+ patients showed worse bone quality (lower BMS) BMS (79.6+12.7) than controls (84.9±6.2, P=0.013) (mean±S.D.). HIV+ patients receiving ART had lower BMS than controls (76±8) (P<0.001 vs controls) and also compared with HIV+ without HAART (BMS 81±14) although the difference was not significant. T-scores in lumbar spine (−1.5+1.7) and total hip (−1.2+1.7) were, on average, in the range of osteopenia in the HIV+ patients. No differences in BMD were observed between HIV+ and controls (P=0.38 and P=0.67 for lumbar spine and total hip respectively). There was no correlation between BMS and lumbar spine BMD (R2=0.002, P=0.80) or total hip BMD (R2=0.002, P=0.81). In a subset of four HIV patients with vertebral fractures BMS was 72±4 significantly lower than controls (P<0.001) and also than the rest of HIV group P<0.05. In this subgroup there were no differences in BMD (lumbar spine) with the rest of HIV group, nor with controls.
Conclusions: Microindentation is a new feasible technique that seems to be superior to BMD to study bone quality, and therefore bone toxicity. HIV infected patients have deterioration in bone quality measured by microindentation and this effect seems more pronounced in those receiving ART.
17 May 2014 - 20 May 2014