Dual-Energy X-Ray Absorptiometry And Calculated Frax Risk Scores May Underestimate Osteoporotic Fracture Risk In Vitamin D-Deficient Veterans With Hiv Infection

Abstract

Objective We evaluated the utility of the World Health Organization Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency. Methods This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the WHO FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures. Results We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between −1 and −2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant. Conclusion We found a high prevalence of subclinical vertebral fractures among vitamin D–deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population.

HIV infection and bone disease

“…The above studies have been restricted to clinical fractures, and there are few data on the prevalence and incidence of morphometric vertebral fractures; these, whilst often asymptomatic, are associated with a significantly increased risk of future fracture. In a retrospective study from the USA in 232 HIV‐infected individuals with vitamin D deficiency, subclinical vertebral fractures were detected in 46.6% . Borderi et al .…”

“…In 1006 HIV‐infected men and women from the USA, osteoporosis, defined as a BMD T‐score ≤−2.5, was associated with a significantly increased risk of incident fracture (adjusted HR 4.02; 95% CI 2.02, 8.01) . However, osteoporosis, defined as above, has not been found to be a good predictor of morphometric vertebral fractures .…”

The Hidden Burden of Fractures in People Living With HIV

“…The subjects in the lowest quartile of TBS had a higher prevalence of vertebral fractures . This observation is interesting because BMD appears to underestimate the incidence of vertebral fractures in the same way as in non‐HIV subjects …”

Bone Loss in HIV Infection

“…As the OREP guidelines note, the WHO diagnostic T-score criteria for DXA were designed for postmenopausal women, and men 50 years of age and older, and may not be applicable to a younger, HIV-infected population [4, 105•]. Additionally, studies involving the VACS-VC show that each modality underestimates fracture risk in the setting of HIV infection, although FRAX improves when HIV is included as a cause of secondary osteoporosis [108, 109]. In HIV-infected men in the United Kingdom with a median age of 45 years, FRAX had a poor sensitivity and specificity for osteoporosis compared with DXA [110].…”