Time of progression to osteopenia/osteoporosis in chronically HIV-infected patients: screening DXA scan.

Background: Algorithms for bone mineral density (BMD) management in HIV-infected patients are lacking. Our objective was to assess how often a dual-energy x-ray absorptiometry (DXA) scan should be performed by assessing time of progression to osteopenia/osteoporosis.
Methods: All DXA scans performed between 2000 and 2009 from HIV-infected patients with at least two DXA were included. Time to an event (osteopenia and osteoporosis) was assessed using the Kaplan-Meier method. Strata (tertiles) were defined using baseline minimum T scores. Differences between strata in time to an event were compared with the log-rank test.
Results: Of 391 patients (1,639 DXAs), 49.6% had osteopenia and 21.7% osteoporosis at their first DXA scan. Of the 112 (28.6%) with normal BMD, 35.7% progressed to osteopenia; median progression time was 6.7 years. These patients were stratified: "low-risk" (baseline minimum T score >-0.2 SD), "middle-risk" (between -0.2 and -0.6 SD), and "high-risk" (from -0.6 to -1 SD); median progression time to osteopenia was 8.7, >7.2, and 1.7 years, respectively (p<0.0001). Of patients with osteopenia, 23.7% progressed to osteoporosis; median progression time was >8.5 years. Progression time was >8.2 years in "low-risk" tertile (T score between -1.1 and -1.6 SD), >8.5 years in "middle-risk" (between -1.6 and -2), and 3.2 years in "high-risk" (from -2 to -2.4) (p<0.0001).
Conclusions: Our results may help to define the BMD testing interval. The lowest T score tertiles would suggest recommending a subsequent DXA in 1-2 years; in the highest tertiles, ≥6 years. Early intervention in patients with bone demineralization could reduce fracture-related morbidity/mortality.