title: Bone mineral density in patients with idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  Decreased bone mineral density (BMD) has been reported in patients with interstitial lung disease. However, BMD has not been evaluated in steroid-naïve patients with idiopathic pulmonary fibrosis (IPF). We aimed to measure vertebral BMD and investigate its relationship with clinical features in steroid-naïve patients with IPF.
  
  
  METHODS
  We recruited 55 consecutive male patients with steroid-naïve IPF; 55 male smokers without chronic obstructive pulmonary disease or interstitial lung disease, matched by age, body mass index, and pack-years of smoking (control smokers); and 27 healthy young adults. Thoracic vertebral BMD was measured by computed tomography (CT). We further investigated the relationship of BMD with clinical features and quantitative CT indices of lung density in patients with IPF.
  
  
  RESULTS
  The thoracic vertebral BMD of patients with IPF was significantly lower than that of control smokers (139.9 ± 28.5 mg/mL vs 160.9 ± 39.5 mg/mL, p < 0.01). Fifteen patients (27.2%) had BMD more than 2.5 SD below the mean BMD of young adults. In patients with IPF, emphysema volume (EV) and its ratio to total lung volume (EV%) had a significantly negative correlation with BMD (r = -0.28, p = 0.04 and r = -0.39, p < 0.01, respectively). In stepwise multiple regression analysis, EV% was an independent explanatory variable for thoracic vertebral BMD.
  
  
  CONCLUSIONS
  A substantial percentage of steroid-naïve IPF patients had decreased BMD, and a significant association was observed between the extent of emphysema and BMD in IPF.
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ikezoe
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan. Electronic address: hanta@kuhp.kyoto-u.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Handa
authors.affiliation: Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kiminobu
authors.initials: K
authors.lastname: Tanizawa
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Oguma
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hamada
authors.affiliation: Department of Respiratory Medicine, Fukui Red Cross Hospital, Fukui, Japan.
authors.forename: Kizuku
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Respiratory Medicine, Saiseikai Noe Hospital, Osaka, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Aihara
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sokai
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Nakatsuka
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Muro
authors.affiliation: Kyoto Central Clinic/Clinical Research Center, Kyoto, Japan.
authors.forename: Sonoko
authors.initials: S
authors.lastname: Nagai
authors.affiliation: Louis Pasteur Center for Medical Research, Kyoto, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Uno
authors.affiliation: Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chin
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Motonari
authors.initials: M
authors.lastname: Fukui
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000503:physiopathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D012907:Smoking / Q000503:physiopathology; D013904:Thoracic Vertebrae / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Bone mineral density; Combined pulmonary fibrosis and emphysema; Idiopathic pulmonary fibrosis