Evaluation of Quantitative Ultrasonography versus Dual X-ray Absorptiometry for Bone Status Monitoring in South African Children Living with HIV
Name: Jackson A. Roberts
School: Vagelos College of Physicians and Surgeons, Class of 2024, Varmus Global Scholar 2021
Mentor: Michael T. Yin, MD, MS
Abstract
Does bone quality assessed by quantitative ultrasonography (QUS) correlate with the gold-standard dual x-ray absorptiometry (DXA) for bone status monitoring in children living with HIV (CLHIV)? CLHIV have decreased bone mineral content (BMC) and density (BMD), increasing risk for future bone-related injury. While DXA is the gold-standard for bone status monitoring, it lacks availability in resource-constrained settings (RCS). QUS offers an alternative owing to its portability, low cost, and ease of handling. While QUS has previously demonstrated differences in bone quality between CLHIV and controls, its correspondence to DXA remains unexplored. Data was obtained at enrollment and 12-month follow-up from CHANGES, a longitudinal cohort of perinatally HIV-infected children in Johannesburg, South Africa. BMC and BMD of the whole body, lumbar spine, and distal 1/3 radius were measured by DXA. Calcaneal speed of sound (SOS) and broadband ultrasound attenuation (BUA) and radius SOS were obtained by QUS, and calcaneal stiffness index (SI) was calculated. Spearman correlations were performed between QUS measures and DXA at enrollment, follow-up, and percent changes between the two visits. At enrollment and follow-up, Achilles BUA and SI correlated strongly with DXA measurements, while radial QUS displayed only modest correlations at enrollment. QUS did not correlate with DXA longitudinally as measured by percent change. At cross-section, Achilles QUS corresponds strongly to DXA and may represent a viable alternative in RCS. Longitudinally, the two methods do not correlate well, which may reflect that each method captures related, yet distinct, aspects of bone architecture.