Reduced quantitative ultrasound bone mineral density in HIV-infected patients on antiretroviral therapy in Senegal

Abstract

Background: Bone status in HIV-infected patients on antiretroviral treatment (ART) is poorly documented in resource-limited settings. We compared bone mineral density between HIV-infected patients and control subjects from Dakar, Senegal.

Methods: A total of 207 (134 women and 73 men) HIV-infected patients from an observational cohort in Dakar (ANRS 1215) and 207 age- and sex-matched controls from the general population were enrolled. Bone mineral density was assessed by quantitative ultrasound (QUS) at the calcaneus, an alternative to the reference method (i.e. dual X-absorptiometry), often not available in resource-limited countries.

Results: Mean age was 47.0 (±8.5) years. Patients had received ART for a median duration of 8.8 years; 45% received a protease inhibitor and 27% tenofovir; 84% had undetectable viral load. Patients had lower body mass index (BMI) than controls (23 versus 26 kg/m(2), P<0.001). In unadjusted analysis, QUS bone mineral density was lower in HIV-infected patients than in controls (difference: -0.36 standard deviation, 95% confidence interval (CI): -0.59;-0.12, P = 0.003). Adjusting for BMI, physical activity, smoking and calcium intake attenuated the difference (-0.27, CI: -0.53;-0.002, P = 0.05). Differences in BMI between patients and controls explained a third of the difference in QUS bone mineral density. Among patients, BMI was independently associated with QUS bone mineral density (P<0.001). An association between undetectable viral load and QUS bone density was also suggested (β = 0.48, CI: 0.02;0.93; P = 0.04). No association between protease inhibitor or tenofovir use and QUS bone mineral density was found.

Conclusion: Senegalese HIV-infected patients had reduced QUS bone mineral density in comparison with control subjects, in part related to their lower BMI. Further investigation is needed to clarify the clinical significance of these observations.

Figure 1. Mean QUS bone mineral density expressed as T-score (and 95% confidence interval) in HIV-infected patients and controls, separately for men and women.