Effect of Losartan on Airway Mucociliary Dysfunction in Patients With COPD and Chronic Bronchitis

Inclusion Criteria: 1. Fulfill one of the group definitions above 2. Age between 35 and 75 years old 3. Clinical diagnosis of chronic bronchitis, defined as productive cough for at least 3 months per year for at least two consecutive years 4. Stable maintenance of all current medication therapy for 3 months, including ARBs for treated groups Exclusion criteria 1. Current therapy with Angiotensin-converting-enzyme (ACE) inhibitor,or Intolerance to Angiotensin II receptor blockers (ARB) 2. Women of child bearing potential 3. Current use of nonsteroidal antiinflammatory drugs or potassium supplementation, treatment with aliskiren, anticoagulation 4. COPD exacerbation requiring treatment within 6 weeks of the screening visit 5. Oral corticosteroid use within 6 weeks of the screening visit 6. Significant hypoxemia (oxygen saturation \<90% on room air), chronic respiratory failure by history (pCO2 \> 45 mmHg) and forced expiratory volume in 1 second (FEV1) below 40%, clinical evidence of cor pulmonale 7. Untreated arterial hypertension (systolic blood pressure \>140 mm Hg, diastolic blood pressure \> 90 mm Hg) 8. Ability to understand and willingness to sign consent documents 9. Blood pressure less than 100 mm Hg systolic or 70 mm Hg diastolic while standing at the screening visit 10. Cardiac, renal, hepatic (LFTs \> 3x normal upper limit), neurological, psychiatric, endocrine or neoplastic diseases that are at the discretion of the investigator, to interfere with participation in study 11. History of renal artery stenosis 12. Concomitant airway disorders other than COPD and chronic bronchitis, such as bronchiectasis and asthma (history and reversible airflow obstruction by American Thoracic Society (ATS) criteria) 13. History of pulmonary malignancies, and any other malignancies in the last 5 years 14. History of thoracic surgery. 15. Acute pulmonary exacerbation within 6 weeks from the Screening Visit. 16. Subjects with no airflow obstruction by spirometry but with a decrease in diffusing capacity of lung for carbon monoxide(DLco) possibly indicating emphysema. 17. Significant exposure to environmental tobacco smoke or atmospheric or occupational pollutants 18. Urine pregnancy positive test at the Screening Visit.