The potential value of FRAX index and bone turnover markers to identify osteoporosis in COPD patients

Chronic Obstructive Pulmonary Disease (COPD) is associated with numerous extrapulmonary diseases including osteoporosis. The incidence of osteoporosisin COPD patients is high and its early detection would prevent significant associated morbidity. To determine the utility of Fracture Risk Assessment Tool ( FRAX) index and bone turnover markers (BTM) for the diagnosis of osteoporosisin COPD patients. This is a pilot study of 50 COPD patients followed at a Pulmonary Service. Age, sex, pack-yearsof smoking status, lung function, FRAXindex and BTM (betacrosslap, osteocalcinand N-terminal propeptide of type 1 procollagen [P1NP]) were recorded. Bone densitometrywas performed on all patients, and was classified as healthy or osteoporotic according to WHO criteria. The potential utility of FRAXindex and BTM was explored by ROC analysis. Patient characteristics are described in Table 1. Excluding densitometric values, the area under the curve (AUC) for major fracture and hip fracture was 0.72 and 0.73, respectively; and the AUC for betacrosslap, osteocalcinand P1NP were 0.70, 0.74 and 0.63, respectively (Figure 1). The FRAXindex and BTM have potential value in the screening for the early diagnosis of osteoporosisin COPD patients. The completion of our study will allow the identification of a useful cutoff point for early screening.