Abstract
Background
Osteoporosis is known as a major systemic effect of COPD. Recent studies demonstrated high prevalence of vertebral fractures in patients with COPD. We aim to investigate the determinants of bone mineral density in the lumbar spine (L-BMD) in stable patients with COPD.
Methods
L-BMD was determined by dual energy X-ray absorptiometry and serum levels of undercarboxylated osteocalcin (ucOC) and tartrate-resistant acid phosphatase type 5b (TRAP- 5b) were measured in 38 outpatients with COPD (mean age:71 yr, mean %FEV1:46.4%). The extent of pulmonary emphysema was evaluated by chest CT scan on the basis of Goddard classification and 6 min walk test was assessed. Nutritional status was evaluated by body mass index (BMI) and fat-free mass index (FFMI) measured by bioelectrical impedance analysis.
Results
L-BMD was decreased in 12 patients (32%). Serum levels of ucOC and TRAP- 5b were significantly elevated in underweight patients with COPD compared with control subjects. L-BMD was significantly correlated with serum ucOC levels, FFMI, %DLco/VA and Goddard scores. By stepwise regression analysis, variables significantly contributing to L-BMD were FFMI and serum ucOC levels. Total variance explained in this model was 65% for L-BMD.
Conclusion
FFMI and serum ucOC levels were important predictor of osteoporosis.
- © 2014 ERS
