RESUMEN
BACKGROUND AND AIMS: The environmental factors, apart from gluten ingestion predisposing to coeliac disease are poorly known. Smoking is associated with many immune-mediated diseases, but research on coeliac disease is scarce. This study aims to investigate how smoking affects the clinical presentation, presence of comorbidities and response to gluten-free diet in coeliac disease. METHODS: Altogether 815 adults with coeliac disease participated in a nationwide cross-sectional study. Participants were interviewed and smoking habits (never, former, or current smoker), clinical presentation of coeliac disease and presence of comorbidities were elicited. Serology and severity of small bowel mucosal lesions at diagnosis were gathered from the participants' medical records and follow-up serology was measured. Gastrointestinal symptoms and psychological well-being were assessed using validated questionnaires. RESULTS: Current smokers were more often male and were diagnosed at younger ages than never or former smokers. There were no differences between the groups in clinical presentation, severity of symptoms or mucosal lesions at diagnosis or in dietary compliance and clinical, serological, and histological recovery. Musculoskeletal disorders, particularly osteoporosis and osteopenia, were more common in never smokers than in other groups (14.5% vs. 5.1% and 4.1%, p<0.001), and cardiovascular disorders were diagnosed more often in former smokers (36.2% vs. 23.5% and 21.9%, p=0.003). CONCLUSIONS: Smoking does not seem to have an impact on the clinical presentation, severity of symptoms or mucosal damage in coeliac disease. Histological and clinical recovery as well as seroconversion on gluten-free diet are not affected by smoking status.