The objectives of this research grant are to determine the association of hypoxia with the severity of osteoporosis in the patients with bronchiectasis and whether the mechanism of inflammation is triggered by inflammasones, which makes it more prone to osteoporosis in patients with bronchiectasis.

80 patients with proven bronchiectasis, diagnosed by high-resolution computed tomography (HRCT), will be recruited from our outpatient clinic of Chang Gung Memorial Hospital with written informed consent. Inclusion criteria are: daily sputum > 10 ml; absence of asthma or other unstable systemic diseases; and "steady-state" bronchiectasis (< 10% alteration of 24 h sputum volume, FEV1, and FVC, and in the absence of deterioration in respiratory symptoms at baseline visits). Exclusion criteria include: unreliable clinic attendance; regular user of inhaled or oral corticosteroids; history of lung resection and known asthma defined according to American Thoracic Society guidelines.

The lung function and desaturation will be assessed by six-minute walking tests and the severity of disease will be evaluated by HRCT scores. Peripheral blood sample (40ml/person) is performed to analyze the bone turnover markers and the level of Hif in PBMC.

Inclusion Criteria:

1. willing to sign a written consent form
2. Male and female subjects with bronchiectasis diagnosed by high-resolution computed tomography
3. willing to accept 6-minute exercise pulmonary function test and blood draw
4. Men and women over the age of 20
5. Has undergone chest computed tomography and bone density examination in the recent five years

Exclusion Criteria:

1. pregnant women or lactating women
2. asthma, lung resection history before the screening period
3. active Tuberculosis infection
4. Have received oral steroid treatment within 30 days
5. current acute attack or clinical symptoms instability of bronchiectasis

80 adult patients with proven bronchiectasis, diagnosed by high-resolution computed tomography (HRCT), will be recruited from our outpatient clinic of Chang Gung Memorial Hospital with written informed consent. The inclusion and exclusion criteria are described above.