The Relationship between Smoking Status, Carbon Monoxide Levels and Quality of Life, Disease Characteristics in Inflammatory Bowel Diseases

Objective: The aim of the study was to analyze the relationship between smoking status and exhaled carbon monoxide (E-CO) levels, quality of life, and disease characteristics in patients with inflammatory bowel disease. Method: The demographic and disease characteristics and smoking status of 121 patients with inflammatory bowel disease who presented our hospital between 01.12.2020 and 01.03.2021 were investigated. After the first follow-up, the E-CO levels of these participants were measured every four consecutive weeks. The mean of these E-CO readings was accepted as the main E -CO value. After one month after their first application SF-36 Quality of Life Scale was applied. The relationship between these variables was investigated. Results: The mean age of the participants was 42.06 +/- 14.9 years, and 36.3% were active smokers. While patients with Crohn's disease (CD) exhibited a higher smoking rate, smokers with ulcerative colitis (UC) registered significantly higher mean CO ppm readings (p<0.05). The general health components of smoker UC patients were higher than those of non-smokers (p<0.05). A weak correlation was determined between mean number of cigarettes smoked per day, mean CO ppm, Fagerstrom Nicotine Dependency Test (FNDT), package year, and the physical and mental components of SF-36 in the UC group (p<0.05). There was a weak negative correlation between mental components and mean E-CO in the CD group (p=0.027). No difference was observed in the non-smoker group between participants exposed to second-hand smoke and those with no such exposure (p>0.05). Conclusion: Our results revealed that smoking has a weak positive effect on the quality of health in patients with UC, but no effect on patients with CD.