Evaluation of the fracture risk assessment tool for determining bone disease and the impact of secondary causes of osteoporosis in people living with HIV

Abstract

Background Among HIV-infected individuals, screening for bone disease is encouraged to assess reversible risk factors and plan therapeutic interventions. Objective We assessed the usefulness of Fracture Risk Assessment (FRAX) tool to identify candidates for dual X-ray absorptiometry (DXA) scan, or individuals with bone loss progression. We further explored how secondary causes of osteoporosis are reflected on FRAX. Methods Longitudinal study of 217 consecutive individuals (mean, 45.8 years, 24% females) included after DXA scan. FRAX was calculated without/with femoral neck bone mineral density (BMD), checking the box of “secondary osteoporosis” for all the individuals. Results Low BMD was observed in 133/217 (61%) individuals, of whom 98.5% had not been selected as candidates for DXA by current FRAX thresholds. Specifically, 23% of individuals aged <50 had low BMD but none was candidate for DXA. Adding BMD data, FRAX results increased by 50–100%, with 2/217 individuals (1%) above the thresholds. Classical and HIV-related secondary causes of osteoporosis (observed in 98% overall) correlated with low BMD, modifying significantly FRAX results (HCV coinfection, +124%; longer time of HIV infection, +93%; longer time on antiretroviral therapy, +147%; tenofovir exposure +36%). Individuals with lower BMD and higher FRAX results at inclusion had less bone decline in a follow-up DXA after a median of 3.5 years. Conclusions Currently recommended FRAX thresholds are not useful to select candidates for DXA scan, which could delay its performance in a population with a high prevalence of secondary factors for low BMD. Classical and HIV-related factors alter BMD and fracture risk estimation.

Keywords

• frax
• fracture risk
• bone disease
• secondary osteoporosis
• bone mineral density
• dual-energy x-ray absorptiometry