Pulmonary function in ulcerative colitis

Pulmonary involvement in ulcerative colitis (UC) is thought to be rare. There is not a definite document about the question that "Is the lung a target organ in inflammatory bowel disease?" The aim of the present study is to compare lung function between cases with UC and healthy controls. This study will also be of interest about searching the outbreak of pulmonary function abnormalities in a sample of Iranian patients with UC and factors associated with severity of UC. In an analytic cross sectional study between July 2006 and September2007, we evaluated 70 patients with histologically confirmed UC and 70 matchedhealthy people. Our checklist addressed demographic variables, symptoms, smoking behavior, drugs, laboratory findings and pulmonary function tests. None of the lung volumes and capacities were significantly different in cases as compared to controls. Severity of UC was mild in 65.7%. It was correlated with smoking (P=0.019) and allergy (P=0.017). Patients with moderate UC had lower hemoglobin (P<.001), MCH (P=0.002), MCV (P=0.047), MCHC (P=0.028) and higher REFF (P=0.032) and BF (P=0.01). The controversies about the relation between UC and lung disease can be due to different sample sizes, activity of UC at the time of measurement of lung volumes, methods of measuring lung capacities at the time of PFT and different nationalities.