title: Relationship between pulmonary emphysema and osteoporosis assessed by CT in patients with COPD.
abstract: BACKGROUND
  Osteoporosis is one of the important systemic features of COPD. Although COPD itself is regarded as one risk factor for osteoporosis, the relationship between the extent of emphysema and reduced bone density is still unclear. Our first aim was therefore to measure vertebral bone density and the percentage of low-attenuation area (LAA%) in the lungs using chest CT scans in COPD patients. Our second aim was to investigate the relationships among CT scan measurements, anthropometric parameters, and pulmonary function.
  
  
  METHODS
  Chest CT scans and pulmonary function tests were performed in 65 male patients with COPD. Using CT images, the CT scan density of the thoracic and lumbar vertebrae (T4, T7, T10, and L1) and the LAA% were measured quantitatively, and their correlations were analyzed.
  
  
  RESULTS
  Linear regression analyses revealed that LAA% had a significant negative correlation with bone mineral density (BMD) [r = -0.522]. In addition, multiple regression analysis showed that only LAA% and body mass index (BMI) were predictive of BMD among age, BMI, smoking index, FEV(1), arterial blood gas, and LAA%.
  
  
  CONCLUSIONS
  The extent of pulmonary emphysema significantly correlated with reduced bone density. Our study suggested that COPD itself could be a risk factor for osteoporosis and that chest CT scanning is useful for the management of COPD as a systemic disease.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ohara
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address: t_hirai@kuhp.kyoto-u.ac.jp.
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Muro
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Haruna
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Terada
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kinose
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Marumo
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Ogawa
authors.affiliation: Department of Experimental Therapeutics, Kyoto University, Kyoto, Japan.
authors.forename: Yuma
authors.initials: Y
authors.lastname: Hoshino
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.affiliation: Department of Physical Therapeutics, Kyoto University, Kyoto, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000368:Aged; D015519:Bone Density; D003430:Cross-Sectional Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015203:Reproducibility of Results; D012307:Risk Factors; D014057:Tomography, X-Ray Computed