Bone mineral density in patients with idiopathic pulmonary fibrosis

Kohei Ikezoe， Tomohiro Handae， Kiminobu Tanizawa， Takeshi Kubo， Tsuyoshi Oguma， Satoshi Hamada， Kizuku Watanabe， Kensaku Aihara， Akihiko Sokai， Yoshinari Nakatsuka， Shigeo Muro， Sonoko Nagai， Kazuko Uno， Kazuo Chin， Motonari Fukui， Toyohiro Hirai， Michiaki Mishima

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.

Conclusion

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.

respiratory medicine

September 2015Volume 109, Issue 9, Pages 1181–1187

DOI: http://dx.doi.org/10.1016/j.rmed.2015.06.014 |