title: Impact of COPD exacerbations on osteoporosis assessed by chest CT scan.
abstract: BACKGROUND
  COPD pathology involves not only the lungs but also extrapulmonary abnormalities. Osteoporosis is one of the most important abnormalities because it may cause vertebral compression fractures and deteriorate pulmonary function. COPD patients have many risk factors for osteoporosis, such as low BMI, decreased activity, systemic inflammation, and use of corticosteroids. Some of these factors have been shown to deteriorate with COPD exacerbations. We previously demonstrated the correlation between emphysema and osteoporosis and between emphysema progression and COPD exacerbations. Thus, the hypothesis that exacerbation causes osteoporosis progression in COPD patients was investigated.
  
  
  METHODS
  Forty-two COPD patients not on osteoporosis treatment for over 2 years were recruited. During follow-up, exacerbations had been prospectively recorded. Thoracic vertebral bone mineral density (BMD) was measured using chest CT, and the annual change in BMD was calculated. The change was compared between patients with and without a history of exacerbations.
  
  
  RESULTS
  The decrease in thoracic vertebral BMD was greater in patients with than in those without a history of exacerbations (median ΔBMD mg/ml·year: -3.78 versus -0.30, p = 0.02). Moreover, multivariate regression analysis showed that exacerbations and baseline PaO₂ were independent predictors of the BMD decrease (R² = 0.20, p = 0.007, and R² = 0.09, p = 0.03, respectively) after adjustment for baseline age, smoking status, and airflow limitation.
  
  
  CONCLUSIONS
  This is the first longitudinal study to demonstrate that COPD exacerbations are independently associated with osteoporosis progression. Osteoporosis progression should be evaluated in COPD patients, especially in those with a history of frequent exacerbations.
authors.affiliation: Department of Respiratory Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kiyokawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Muro
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Oguma
authors.forename: Susumu
authors.initials: S
authors.lastname: Sato
authors.forename: Naoya
authors.initials: N
authors.lastname: Tanabe
authors.forename: Tamaki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Megumi
authors.initials: M
authors.lastname: Kudo
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kinose
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kondoh
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubo
authors.forename: Yuma
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Emiko
authors.initials: E
authors.lastname: Ogawa
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000009:adverse effects; D015992:Body Mass Index; D015519:Bone Density; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications* / Q000000981:diagnostic imaging; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000000981:diagnostic imaging; D011656:Pulmonary Emphysema / Q000150:complications* / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic; D012307:Risk Factors; D012907:Smoking; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents