Smoking and ulcerative colitis: a community study

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

Dose-response relationship between cigarette smoking and risk of ulcerative colitis: a nationwide population-based study

BACKGROUND

Former cigarette smokers are at risk of developing ulcerative colitis (UC). However, the impact of smoking behavior on the occurrence of UC according to the amount smoked remains elusive. We aimed to determine the relationship between smoking behavior and the risk of UC development.

METHODS

We conducted a retrospective population-based cohort study using the National Health Insurance Service database in South Korea. From January 2009 to December 2012, 23,235,771 individuals over 18 years of age who underwent a national health examination were enrolled and followed until 2016. All study participants were divided into the following 3 groups: nonsmokers, former smokers, and current smokers. The primary endpoint was newly developed UC.

RESULTS

Compared with nonsmokers, the risk of UC development was significantly higher in former smokers [adjusted hazard ratio (aHR) 1.83; 95% confidence interval (CI) 1.73-1.95] but significantly lower in current smokers (aHR 0.92; 95% CI 0.87-0.98). Among current smokers, individuals who stopped smoking after the baseline evaluation had a significantly higher risk of UC development than those who continued to smoke (aHR 2.42; 95% CI 2.10-2.80). The risk of UC development among former smokers was significantly associated with smoking amount and duration. Among current smokers, however, the risk of UC development was not correlated with the cumulative lifetime smoking exposure. The preventive effect of current smoking on UC development was observed only in men (aHR 0.90; 95% CI 0.84-0.96).

CONCLUSIONS

Compared with nonsmokers, former smokers have a significantly higher risk of UC development that may be proportional to the cumulative smoking exposure.

Smoking prevalence and its influence on disease course and surgery in Crohn's disease and ulcerative colitis

BACKGROUND

Smoking demonstrates divergent effects in Crohn's disease (CD) and ulcerative colitis (UC). Smoking frequency is greater in CD and deleterious to its disease course. Conversely, UC is primarily a disease of nonsmokers and ex-smokers, with reports of disease amelioration in active smoking.

AIM

To determine the prevalence of smoking and its effects on disease progression and surgery in a well-characterised cohort of inflammatory bowel diseases (IBD) patients.

METHODS

Patients with smoking data of the Sydney IBD Cohort were included. Demographic, phenotypic, medical, surgical and hospitalisation data were analysed and reported on the basis of patient smoking status.

RESULTS

1203 IBD patients were identified comprising 626 CD and 557 UC with 6725 and 6672 patient-years of follow-up, respectively. CD patients were more likely to smoke than UC patients (19.2% vs. 10.2%, P < 0.001). A history of smoking in CD was associated with an increased proportional surgery rate (45.8% vs. 37.8%, P = 0.045), requirement for IBD-related hospitalisation (P = 0.009) and incidence of peripheral arthritis (29.8% vs. 22.0%, P = 0.027). Current smokers with UC demonstrated reduced corticosteroid utilisation (24.1% vs. 37.5%, P = 0.045), yet no reduction in the rates of colectomy (3.4% vs. 6.6%, P = 0.34) or hospital admission (P = 0.25) relative to nonsmokers. Ex-smokers with UC required proportionately greater immunosuppressive (36.2% vs. 26.3%, P = 0.041) and corticosteroid (43.7% vs. 34.5%, P = 0.078) therapies compared with current and never smokers.

CONCLUSIONS

This study confirms the detrimental effects of smoking in CD, yet failed to demonstrate substantial benefit from smoking in UC. These data should encourage all patients with IBD to quit smoking.

Is current smoking still an important environmental factor in inflammatory bowel diseases? Results from a population-based incident cohort

BACKGROUND

Previous studies suggest that smoking is an important environmental factor in inflammatory bowel diseases (IBDs), with dichotomous effects in ulcerative colitis (UC) and Crohn's disease (CD). The aim of this study was to analyze the relationship between smoking and IBD risk in a population-based database from Veszprem Province, which included incident cases diagnosed between January 1, 1977, and December 31, 2008.

METHODS

Data from 1420 incident patients were analyzed (UC: 914, age at diagnosis: 38.9 years; CD: 506, age at diagnosis: 31.5 years). Both inpatient and outpatient records were collected and comprehensively reviewed. Overall, smoking frequency in the adult general population was 36.1%.

RESULTS

Of patients with CD, 47.2% were current smokers at diagnosis. Smoking was more frequent in male patients (P = 0.002) and was associated with an increased risk of CD (odds ratio, 1.96; 95% confidence interval, 1.63-2.37; P < 0.001). In contrast, current smoking was protective against UC (odds ratio, 0.33; 95% confidence interval, 0.27-0.41). The effect of smoking was linked to gender (in CD, more deleterious in male patients) and age at diagnosis and was most prominent in young adults, with a difference already being seen in 18- to 19-year-olds. In CD, a change in disease behavior (P = 0.02), location from ileal or colonic to ileocolonic (P = 0.003), arthritis/arthropathy (P = 0.002), need for steroids (P = 0.06), or AZA (P = 0.038) was more common in current smokers. Smoking in UC was associated with more extensive disease (P = 0.01) and a tendency for decreased need for colectomy (P = 0.06).

CONCLUSIONS

Current smoking was associated with the risk of IBD. This effect was linked to gender and age at diagnosis and was most prominent in young adults. No association was observed in pediatric or elderly patients. The deleterious and protective effects of smoking on the course in CD and UC were partially confirmed.

Review article: Ulcerative colitis, smoking and nicotine therapy

BACKGROUND

Smoking is the best-characterised environmental association of ulcerative colitis (UC). Smoking has been observed to exert protective effects on both the development and progression of UC.

AIMS

To examine the association between UC and smoking, possible pathogenic mechanisms and the potential of nicotine as a therapeutic agent in the treatment of UC.

METHODS

A literature search was conducted through MEDLINE, using the MeSH search terms 'ulcerative colitis' and 'smoking' or 'nicotine'. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles.

RESULTS

Ulcerative colitis is less prevalent in smokers. Current smokers with a prior diagnosis of UC are more likely to exhibit milder disease than ex-smokers and nonsmokers. There is conflicting evidence for smokers having reduced rates of hospitalisation, colectomy and need for oral corticosteroids and immunosuppressants to manage their disease. Multiple potential active mediators in smoke may be responsible for these clinical effects, including nicotine and carbon monoxide, but the precise mechanism remains unknown. Nicotine has demonstrated variable efficacy in the induction of remission in UC when compared to placebo and conventional medicines. Despite this, the high frequency of adverse events limits its clinical significance.

CONCLUSIONS

Nicotine's application as a therapeutic treatment in ulcerative colitis is limited. Presently, it may be an option considered only in selected cases of acute ulcerative colitis refractory to conventional treatment options. This review also questions whether nicotine is the active component of smoking that modifies risk and inflammation in ulcerative colitis.

Tobacco dependence and awareness of health risks of smoking in patients with inflammatory bowel disease

BACKGROUND AND AIM

Smoking is a risk factor for developing Crohn's disease (CD) and worsens its outcome. Conversely, in ulcerative colitis (UC), the onset may be triggered by the smoking cessation and smoking may be beneficial. To help to ascertain whether patients with inflammatory bowel disease (IBD) would benefit from attending a smoking cessation clinic, we assessed: first, the prevalence of smoking; second, patients' awareness of the effects of smoking, and finally nicotine dependence in IBD patients compared with the healthy and disease-matched controls.

METHODS

A total of 246 consecutive IBD outpatients (173 patients with CD, 73 patients with UC) completed a questionnaire on smoking habits and its effect on IBD. Smokers were assessed for dependence using the Fagerstrom test for nicotine dependence (FTND) score and their results were compared with those of age, sex, and ethnicity-matched healthy (five controls for each IBD patient) and asthma controls (one control for each IBD patient) attending a smoking cessation clinic.

RESULTS

Thirty five out of 173 patients (20%) with CD and nine out of 73 patients (12%) with UC were current smokers, with 52 out of 173 patients (30%) with CD and 28 out of 73 patients (38%) with UC being ex-smokers. Ninety out of 173 patients (52%) with CD knew that smoking worsens CD, whereas only 15 out of 73 patients (21%) with UC knew of the beneficial effects of smoking on their disease (P=0.032). Knowledge was unrelated to smoking status. In patients with CD, the median (range) FTND score was 3 (0-8) compared with 7 (2-10) in healthy (P<0.001) and 6 (2-9) in asthma controls (P<0.0001). Only seven of the 35 (20%) smoking patients with CD were highly dependent (FTND score ≥6). Similarly, in the patients with UC, the FTND score was 1 (0-4), lower than in healthy, [6 (2-10)], and asthma controls, [7 (4-10); (P<0.004 for both groups)].

CONCLUSION

Patients with CD were better informed about the effects of smoking on their own disease than the patients with UC. Nicotine dependence in IBD patients is lower than in smokers' clinic clients and comparable with that of the general population. Their low nicotine dependence suggests that most IBD patients could be weaned off the smoking habit successfully in the IBD clinic and referral to a smoking cessation clinic was offered to the highly dependent minority and others expressing interest in attending.

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

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 protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing CD and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves CD. 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.

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

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 protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, 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.

Smoking habit and load influence age at diagnosis and disease extent in ulcerative colitis

INTRODUCTION

Cigarette smoking affects susceptibility to ulcerative colitis (UC), but its effects on age at diagnosis, disease extent, and need for surgery are less well defined. We examined these parameters in a detailed retrospective analysis of a large cohort of well-characterized UC patients.

METHODS

499 UC patients (254 male, median age 34.3 yr) were studied. Data were collected on smoking habits, smoking load (pack-years), age at recruitment, age at diagnosis, surgery, and disease extent. Colonoscopic and histological data at both diagnosis and follow-up (median follow-up time 4.6 yr) were available on 349 patients.

RESULTS

Ex-smokers were older at diagnosis than current or nonsmokers, (46.5 yr vs 31.1 or 29.4 yr, respectively, P < 0.001). Before diagnosis, ex-smokers had a higher smoking load than current smokers (13.0 vs 6.94 pack-years, P < 0.001). A Cox model for age at diagnosis, with smoking as a time-dependent covariate, showed that at any age, ex-smokers were significantly more likely to develop UC than current smokers (hazard ratio 1.8, 95% CI 1.41-2.44, P < 0.001). For current smokers at latest colonoscopy, those with extensive disease were the lightest smokers (median 0.320 pack-years), whereas those with healthy colons were the heaviest smokers (median 9.18 pack-years, P= 0.006). At 5 yr, regression of extensive disease was more frequent in current than ex-smokers or nonsmokers (30% current smokers vs 8% nonsmokers and 5% ex-smokers, chi(2)= 30.4, P < 0.001) but these differences were not maintained over a longer time period.

CONCLUSIONS

Smoking habit influences the age at diagnosis and changes in disease extent in UC. Mechanisms are likely to be complex and require further investigation.

Tobacco and IBD: relevance in the understanding of disease mechanisms and clinical practice

Current smoking protects against ulcerative colitis and, after onset of the disease, improves its course, decreasing the need for colectomy. However, smoking increases the risk of developing Crohn's disease and worsens its course, increasing the need for steroids, immunosuppressants and reoperations. Smoking cessation aggravates ulcerative colitis and improves Crohn's disease. The effects of smoking are the sum of contradictory effects of various substances, including nicotine and carbon monoxide, and are modulated by gender, genetic background, disease location and activity, cigarette dose and nicotine concentration. Smokers with ulcerative colitis should not be discouraged from stopping smoking but encouraged to stop, to reduce their risk of cardiopulmonary tobacco-related diseases. In Crohn's disease, smoking cessation has become a major therapeutic goal, particularly in young women and in patients with ileal involvement. A large amount of supportive information, use of nicotine-replacement therapies and antidepressants, and individual counselling might aid the patient in quitting.

Impact of cessation of smoking on the course of ulcerative colitis

OBJECTIVES

The incidence and severity of ulcerative colitis (UC) are higher in nonsmokers than in smokers. The natural course of UC in smokers who stop smoking is not known. The aim of this study was to determine the impact of cessation of smoking on the course of UC among the cohort of patients regularly seen at our institution.

METHODS

The severity of UC, as judged by the occurrence of flare-ups and the need for systemic steroids, immunosuppressive drugs and colectomy, was determined in 32 patients with UC who stopped smoking after the diagnosis of UC. We compared the period after cessation of smoking (7-yr mean follow-up) with the period between the onset of the disease and the cessation of smoking (9-yr mean duration). The course of UC in this group was compared with that of 32 nonsmokers and 32 continuing smokers matched for sex, age, and age at onset.

RESULTS

In patients who quit, cessation of smoking was followed by an increase in the rate of years with active disease (p < 0.01), years with hospitalization (p < 0.05) and years with major medical therapy (oral steroids, intravenous steroids, and azathioprine, p < 0.01). After cessation of smoking, the rate of years with immunosuppressive therapy was significantly greater in ex-smokers and nonsmokers than in continuing smokers (p < 0.01). The risk of colectomy in ex-smokers after smoking cessation was similar to that of nonsmokers and continuing smokers.

CONCLUSIONS

In smokers with UC who stop smoking, the severity of the disease increases after smoking cessation, with an increase in the disease activity and the need for hospital admission and major medical therapy. In addition, the need for azathioprine therapy becomes similar to that of nonsmokers.

A critical review of epidemiological studies in inflammatory bowel disease

This review addresses the difficulty in interpreting the results of epidemiological studies in IBD and in making meaningful comparisons between studies. Both ulcerative colitis and Crohn disease appear to be more common in some industrialized countries such as Scandinavia, United Kingdom, North America and less common in Central and Southern Europe, Asia and Africa. Given data showing an increased incidence of ulcerative colitis in the United Kingdom, it is crucial that more studies be conducted in developing countries. While the incidence of Crohn disease has increased strikingly in many areas, the incidence of ulcerative colitis has remained fairly stable in most. This could be due to the rising number of community-based studies, as well as the improved accuracy in diagnosing Crohn disease. Although, the incidence of IBD among Blacks in Africa is low, infection rates are high, life expectancy is lower than in developed countries. Data from the USA suggest that rates are similar in Afro-American and Caucasian populations. Rates for Jewish populations may be slightly higher than in non-Jewish populations but this also varies geographically. Careful attention to genetic, environmental, and socioeconomic factors must be accounted for in these studies. There is no strong evidence to support that IBD is more common in urban than in rural settings and migration towards more accessible health care has not been adequately addressed. Recent epidemiological studies suggest that mortality rates for IBD are similar to that of the general population for the majority of patients. However, older patients with IBD and newly diagnosed cases with severe diseases are at increased risk of dying. Epidemiological studies remain important in assisting with health policy planning and in hypothesis testing of etiological factors. As better diagnostic techniques become widely available and public health registries are increasingly used, it is possible that geographic differences will diminish. International collaborative studies will be better equipped to answer research questions addressing risk factors and disease natural history. We have summarized in Table V the essential criteria to conduct a sound epidemiological study, which would permit future testing of hypotheses among different populations.

The effects of migration on ulcerative colitis: a three-year prospective study among Europeans and first- and second- generation South Asians in Leicester (1991-1994)

OBJECTIVE

Our aim was to measure prospectively the incidence of ulcerative colitis in Leicester City and to compare this with a previous retrospective study in the same area. We also sought to compare the incidence and disease extent in the European community with that of the South Asian community and to compare the disease extent between first- and second-generation South Asian migrants.

METHODS

A 3-yr prospective study of ulcerative colitis in the city of Leicester took place from October 1, 1991 to September 30, 1994 and included all cases resident in Leicester City and diagnosed as having ulcerative colitis, regardless of the extent and severity of the disease.

RESULTS

Extensive colitis was commoner in second-generation migrants than in the first generation (chi2 = 4.3, p = 0.04) and was comparable to the European community. The annual average incidence of ulcerative colitis was 9.1/10(5) population/yr (95% confidence interval [CI] 7.1-11.3), which is similar to the previous retrospective study. However, the annual average incidence of ulcerative colitis in the European population was 7.0/10(5) population/yr (95% CI 5-9.5), whereas that of the South Asian population was 17.2/10(5) population/yr (95% CI 11.8-24.3), confirming that the risk of ulcerative colitis in this particular community is exceptionally high.

CONCLUSIONS

These early results suggest that the disease pattern follows that of the indigenous population after only one generation and requires monitoring over the next decade. The incidence of ulcerative colitis in the South Asian population is high and continuing to rise.

The effect of mesalamine and nicotine in the treatment of inflammatory bowel disease

OBJECTIVE

To characterize the usefulness of mesalamine and nicotine in the treatment of active ulcerative colitis and inactive Crohn's disease.

DATA SOURCES

Citations were selected from the MEDLINE database. Only those involving human subjects, inflammatory bowel disease, and available in English were selected.

STUDY SELECTION

Selection criteria of clinical trials and review articles assessing the effects of mesalamine and nicotine in active ulcerative colitis or inactive Crohn's disease and the utility of reducing steroid dependence or relapse rate. Less than 20% of the articles identified met the selection criteria.

DATA SYNTHESIS

In patients with inactive Crohn's disease, mesalamine 2 g/d significantly reduced the risk of relapse in high-relapse-risk patients compared with placebo, reducing the relapse rate from 71% to 55%, but was ineffective in preventing recurrence of inactive Crohn's disease following surgical resection. Mesalamine 4 g/d was effective in decreasing weaning failure due to steroid dependence by 67%, although the relapse rate was not significant compared with placebo at the end of 12 months. Following surgical resection, mesalamine was unable to significantly reduce the incidence of recurrence compared with placebo at the end of 1 year. In patients with active ulcerative colitis, oral mesalamine 2 and 4 g/d was superior to placebo in inducing remission compared with placebo. Among patients with prior steroid of sulfasalazine treatment, rectal mesalamine 4 g hs achieved a remission rate of 78% in more than 12 weeks of therapy. Other studies have not found a dose-response relationship with lower dosages of mesalamine. Whereas nicotine 15-25 mg/d administered as a transdermal patch produced greater symptomatic improvement in active ulcerative colitis compared with placebo, nicotine 15 mg/16 h produced results no different from those with placebo in maintaining remission in active colitis. Nicotine appears to have an adverse effect on the course of Crohn's disease and is not recommended.

CONCLUSIONS

Mesalamine has demonstrated clinical effectiveness as a therapeutic agent in the treatment of active ulcerative colitis and inactive Crohn's disease. Although its relationship to inflammatory bowel disease has been known for many years, the usefulness of nicotine for the treatment of active ulcerative colitis requires further exploration before it can be recommended as therapeutic agent.

Epidemiology of inflammatory bowel disease: an update

What have epidemiologic studies on IBD taught so far? Consistent findings are as follows: A high incidence of both CD and UC in industrialized countries and an increase in these areas of the incidence of CD during the years 1960-80 followed by a plateau phase, and a more stable pattern in UC during the same period have been found. A greater number of mild cases have probably been diagnosed recently. This also helps to explain the differences in severity and survival between community and referral centre groups. The male to female ratio is greater than 1 in UC, and this is the opposite in CD. Mortality of IBD has decreased during the past decades. As young people are especially prone to develop IBD, most of those affected will have their disease for many years. In developing IBD, genetic influences are of importance. However, epidemiologic studies strongly point to possible interactions between genetically determined features and environmental or other factors. Of these exogenic factors smoking is the most consistent, being of negative influence in CD and protective in UC. Diet and oral contraceptives may influence disease expression, and perinatal events such as viral infections may alter adult susceptibility. The question remains open whether UC and CD are one diseases entity. Similarities in the epidemiologic features of UC and CD support the idea of IBD being one disease. Other findings suggest dividing UC and CD into further subgroups: in CD it has been suggested that fibrostenotic, penetrating, and inflammatory behaviour should be considered different disease entities; in UC some groups consider ulcerative proctitis a disease entity on its own, separating it from the proximally extending colitis. In therapeutic trials this approach has proved to be of importance, and it is not inconceivable that in subgroups, with regard to aetiopathogenetic mechanisms, different factors have to be looked for.

Cutaneous manifestations and consequences of smoking

Cigarette smoking is strongly linked to serious internal diseases such as cancer, cardiovascular disease, and lung disease. However, the external manifestations and consequences of smoking are relatively unknown. Although generally less ominous, the cutaneous manifestations of smoking may be associated with significant morbidity. This article reviews the known adverse effects on the skin of smoking.

Long-term effects of inhaled nicotine

Tobacco smoking has been reported to be associated with increased risk of cardiovascular disease and cancer, particularly of the lungs. In spite of extensive research on the health effects of tobacco smoking, the substances in tobacco smoke exerting these negative health effects are not completely known. Nicotine is the substance giving the subjective pleasure of smoking as well as inducing addiction. For the first time we report the effect on the rat of long-term (two years) inhalation of nicotine. The rats breathed in a chamber with nicotine at a concentration giving twice the plasma concentration found in heavy smokers. Nicotine was given for 20 h a day, five days a week during a two-year period. We could not find any increase in mortality, in atherosclerosis or frequency of tumors in these rats compared with controls. Particularly, there was no microscopic or macroscopic lung tumors nor any increase in pulmonary neuroendocrine cells. Throughout the study, however, the body weight of the nicotine exposed rats was reduced as compared with controls. In conclusion, our study does not indicate any harmful effect of nicotine when given in its pure form by inhalation.

Epidemiology of inflammatory bowel disease in different ethnic and religious groups: limitations and aetiological clues

We present a review of epidemiological studies of inflammatory bowel disease and abdominal tuberculosis in various migrant communities in the United Kingdom. The differences between various South Asian groups such as Gujaratis, Bangladeshis and Punjabis are discussed in the context of age standardisation of incidence data and various dietary and social activities.

Transdermal nicotine for active ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Because anecdotal reports suggest that smoking and nicotine may improve the symptoms of the disease, we examined the effect of nicotine as a supplemental treatment for ulcerative colitis.

METHODS

We treated 72 patients with active ulcerative colitis with either transdermal nicotine patches or placebo patches for six weeks in a randomized, double-blind study. Incremental doses of nicotine were given; most patients tolerated doses of 15 to 25 mg per 24 hours. All the patients had been taking mesalamine, and 12 were receiving low doses of glucocorticoids; these medications were continued without change during the study. Clinical, sigmoidoscopic, and histologic assessments were made at base line and at the end of the study; symptoms were recorded daily on a diary card, and the clinician made a global assessment. Side effects and plasma nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

Seventeen of the 35 patients in the nicotine group had complete remissions, as compared with 9 of the 37 patients in the placebo group (P = 0.03). The patients in the nicotine group had greater improvement in the global clinical grade of colitis (P < 0.001) and the histologic grade (P = 0.03), lower stool frequency (a difference of 1.6 stools daily; P = 0.008), less abdominal pain (P = 0.05), and less fecal urgency (P = 0.009). More patients in the nicotine group had side effects (23, vs. 11 in the placebo group; P = 0.002), the most common of which were nausea, lightheadedness, headache, and sleep disturbance. Withdrawals due to ineffective therapy were more common in the placebo group (3 vs. 8, P = 0.12).

CONCLUSIONS

The addition of transdermal nicotine to conventional maintenance therapy improves symptoms in patients with ulcerative colitis.