Smoking in inflammatory bowel diseases: Good, bad or ugly?

Abstract

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn's disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be p r o t e c t i v e a g a i n s t u l c e r a t i v e c o l i t i s a n d , a f t e r onset of the disease, might improve its course, d e c r e a s i n g t h e n e e d f o r c o l e c t o m y . H o w e v e r , smoking increases the risk of developing Crohn's disease and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves Crohn's disease. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases.

Cigarette smoking alters epithelial apoptosis and immune composition in murine GALT

“…6 Furthermore, smoking is associated with more complicated disease, a higher need for steroids and immunosuppressants and poorer response rate to infliximab. 5,7 Notwithstanding this substantial epidemiological evidence, little is known about the molecular and cellular mechanisms by which smoking affects the gut and interferes with CD pathogenesis. Hypotheses include modulation of humoral and cellular immune responses, changes in intestinal cytokine levels, alterations in mucosal blood flow and modifications in gut permeability or gut motility by smoke exposure.…”

“…A drawback of both human and animal experimental studies is that they generally focus on changes in the-easier accessible-colon, whereas epidemiological data suggest a smoke-induced increase in Crohn's ileitis rather than colitis. 7,8 The purpose of this study was to investigate the influence of cigarette smoke on the mucosal immune system of the small intestine in a murine model. Mice were exposed to main stream cigarette smoke for 24 weeks.…”

Leukocyte myeloperoxidase activity and serum CRP levels as predictive markers of inflammatory disorders amongst Passive smokers

“…More recently, CVD has even been referred to as an inflammatory disease 21,22 . In addition, a link has been established between several other chronic inflammatory diseases and smoking, including, Chronic inflammatory diseases, including chronic obstructive pulmonary disease (COPD) 23 , rheumatoid arthritis, systemic lupus erythematosus 24 and Crohn's disease 25 . has been associated with smoking .Although the mechanisms linking smoking to these diseases are not well understood, inflammatory markers may be valuable in providing explanations for smoking-mediated morbidity and mortality.…”

Evaluation of Lipid Parameters , Liver Function Test , CRP and MDA (as a marker of lipid peroxidation) in Chronic Cigarette Smokers

“…[3][4] It has been recognised that CVD contains a component of inflammation and has even been referred to as an inflammatory disease [5]. In addition, a link has been established between several other chronic inflammatory diseases and smoking, including chronic obstructive pulmonary disease (COPD) [6], rheumatoid arthritis, systemic lupus erythematosus [7] and Crohn's disease [8]. Although the mechanisms linking smoking to these diseases are not well understood, interest in the relationship between inflammatory markers and smoking has been gathering pace in an attempt to provide explanations for smoking-mediated morbidity and mortality.…”