Diagnostic Significance of β-Collagen Degradation Products and Osteocalcin in Chronic Obstructive Pulmonary Disease Complicated with Osteoporosis

Chronic obstructive pulmonary disease is a pulmonary dysfunction common to the middle-aged and elderly population. About 20–60% of patients with moderate or severe chronic obstructive pulmonary disease suffer from different degrees of osteoporosis. A strong relationship between β-collagen degradation products and osteocalcin has been shown in several bone diseases, but their roles in chronic obstructive pulmonary disease remain to be investigated. This study was designed to explore such a relationship in patients with chronic obstructive pulmonary disease complicated with osteoporosis. The β-collagen degradation products were the highest in the serum of patients diagnosed with both chronic obstructive pulmonary disease and osteoporosis followed by those with chronic obstructive pulmonary disease only and osteoporosis only. According to the receiver operating characteristic analysis curves, both β-collagen degradation products and osteocalcin had favorable predictive values for patients with chronic obstructive pulmonary disease, osteoporosis or both. In addition, β-collagen degradation products were negatively correlated with forced expiratory volume in 1 s and bone mineral density, while osteocalcin was positively correlated with them. β-collagen degradation products increase, and osteocalcin decreases in patients with both chronic obstructive pulmonary disease and osteoporosis.