[Predictors of osteopenic syndrome in idiopathic pulmonary fibrosis]

To evaluate the functional state of bone tissue in patients with idiopathic pulmonary fibrosis (IPF), waiting for lung transplantation, and to determine possible predictors of lower bone mineral density (BMD) in this pathology in the pretransplantation period.

Forty-nine IPF patients waiting for lung transplantation were examined. The patients' mean age was 53.4 +/- 6.4 years. BMD in the lumbar spine (L(II)-L(IV)) and femoral neck (FN) was estimated using dual-energy X-ray absorptiometry. All the patients underwent external respiratory function test, pulmonary diffusing capacity (DL(CO)), gasometry, and 6-minute walk test (6'WT).

Osteopenia was recorded in 77% of the examinees, of them 28% had osteoporosis (OP). Normal BMD in both L(II)-L(IV) and FN was found only in 13% of the patients. The T score in L(II)-L(IV) was directly related to body mass index. There was a direct correlation between BMD in L(II)-L(IV) and FN, forced vital capacity (FVC), DL(CO), and arterial blood oxygen saturation (SaO2) and an inverse correlation with arterial carbon dioxide partial pressure (pCO2). No significant correlation was found between the distance covered in 6'WT, FEV1, pO2, and BMD in both L(II)-L(IV) and FN. Six (15%) subjects had atraumatic fractures at different sites.

Osteopenia is a common systemic manifestation in patients with IPF in the pre-transplantation period. BMI, FVC, exercise desaturation, and DL(CO) may be considered as predictors for the development of OP initiated by IPF.