Despite the popular belief that smoking may provide a protective effect for patients with ulcerative colitis (UC), a recent large-scale study found no benefits from smoking in patients with UC.
The study also found that quitting smoking did not worsen the course of the disease in UC patients, confirming that the harm caused by smoking far outweighs any possible benefits.
The study, “The impact of smoking and smoking cessation on disease outcomes in ulcerative colitis: a nationwide population‐based study,” was published in the journal Alimentary Pharmacology and Therapeutics.
A previous study showed that tobacco smoke exposure was associated with approximately half the risk of developing UC. “However, these studies have not evaluated the effect of smoking on corticosteroid dependency, which is increasingly recognized as a key indicator of disease control in the management of UC,” the authors wrote.
Such results have led to a belief that smoking may be beneficial in UC and some patients report that they smoke to improve their disease.
In fact, almost half of all UC patients, when responding to a questionnaire, reported that they were aware of the protective effects that smoking has in UC. Furthermore, one study found that four out of 19 ex-smokers with UC resumed smoking to prevent a disease flare.
However, the relationship between smoking status at time of diagnosis and the subsequent course of disease is still unclear.
“The ongoing belief that tobacco smoke has beneficial effects on disease outcomes in UC may be perpetuating smoking behavior and denying patients the undisputed wider health benefits of smoking cessation,” the researchers stated.
The overall benefits associated with quitting smoking are beyond dispute, but its effect in patients with UC is poorly understood. Therefore, researchers set out to conduct a study to evaluate the effect of smoking status and cessation on disease outcomes in patients with UC.
Using a clinical research database, Clinical Practice Research Datalink (CPRD), researchers identified incident cases of UC from 2005 through 2016. Patients were grouped either as never smokers, former smokers, or smokers based on their smoking status noted two years prior to their UC diagnosis.
Researchers studied 6,754 patients who had new diagnoses of UC, among whom 878 were smokers at time of diagnosis, 2,698 were never smokers and 3,178 were ex-smokers.
Results indicated that smokers had a similar risk of developing flares that required treatment with corticosteroids (anti-inflammatory medicines), use of thiopurine (immune system suppressant), dependency on corticosteroids, hospitalizations and colectomy (a surgical procedure to remove all or part of the colon) in comparison with those who had never smoked.
Furthermore, rates of flares, thiopurine use, corticosteroid dependency, hospitalization, and colectomy were not significantly different between people who continued to smoke and those who quit smoking after a diagnosis of UC.
“Smokers and never-smokers with UC have similar outcomes with respect to flares, thiopurine use, corticosteroid dependency, hospitalization, and colectomy. Smoking cessation was not associated with worse disease course,” the researchers concluded.
“We did not find any benefits of smoking in ulcerative colitis. We hope our study will give people with ulcerative colitis the confidence to avoid smoking and thereby improve their health in general,” Jonathan Blackwell, of St. George’s Healthcare NHS Trust and St. George’s University in London, lead author of the study, said in a press release.
The authors of the study added, “The risks associated with smoking outweigh any benefits. UC patients should be counseled against smoking.”