Biochemical Markers of Bone Turnover in Chronic Obstructive Pulmonary Disease (COPD)

Abstract

PURPOSE: Osteoporosis has a higher prevalence in COPD patients and its etiology is very complex, it has been linked with reduced physical activity, low body mass index (BMD), a worse degree of airflow limitation and glucocorticosteroids treatment. The main objective was to describe the biochemical markers of bone turnover and a Lateral Dual energy X-ray absorptiometry (DXA) scan in COPD patients, and related them. METHOD(S): We determined in peripheral blood of 68 COPD patients, these biochemical markers of bone turnover: Vitamin D, osteocalcin and bone alkaline phosphatase (bone formation markers) and betacrosslaps (bone resorption marker). We used the DXA scan results at lumbar spine and femoral neck closer the blood sample (Hologic QDR-4500w). We classified the blood sample as normal or abnormal using the reference values for gender and age, and correlated it with BMD. RESULT(S): 68 patients, 17 women, median age 70,6 years old (48-88 years). The mean of blood samples results were: - Vitamin D levels: 23,28 ng/ml (5,2 - 73,5) - Osteocalcin levels: 19,63 ng/ml (5,32 - 63,36) - Bone Alkaline Phosphatase levels: 14,88 micrag/l (3,8 - 49,1) - Betacrosslaps levels: 342,66 pg/ml (73,9 - 843,5) 31 patients had a low femoral neck BMD and 34 at the lumbar spine. 77% patients had low Vitamin D levels, 41% low osteocalcin levels and 38% patients had raised the betacrosslaps levels. There were not statistical significance between blood samples and BMD. CONCLUSION(S): 1) More than 50% of patients had pathological DXA results. 2) 2/3 of the sample had low Vitamin D levels. 3) Lumbar spine alteration was more common in COPD patients.