Relationship between pulmonary emphysema and osteoporosis assessed by CT in patients with COPD.
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.
Ohara
Tadashi
T
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Hirai
Toyohiro
T
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address: t_hirai@kuhp.kyoto-u.ac.jp.
Muro
Shigeo
S
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Haruna
Akane
A
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Terada
Kunihiko
K
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Kinose
Daisuke
D
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Marumo
Satoshi
S
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Ogawa
Emiko
E
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Hoshino
Yuma
Y
Department of Experimental Therapeutics, Kyoto University, Kyoto, Japan.
Niimi
Akio
A
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Chin
Kazuo
K
Department of Physical Therapeutics, Kyoto University, Kyoto, Japan.
Mishima
Michiaki
M
Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
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