Oral contraceptive use and cigarette smoking in Crohn's disease

Contraception in autoimmune diseases

Autoimmune diseases (AIDs) affect women and men with a 2:1 ratio, which suggests that hormonal contraceptives play a role in their clinical course. Combined oral contraceptives have complex, sometimes contradictory, effects on AIDs; they can worsen the situation in women with systemic lupus erythematosus and with anti-phospholipid syndrome, conditions in which they are contraindicated. Early studies indicated a positive effect on rheumatoid arthritis (RA), whereas more recent trials failed to do so, possibly because of the lowering of oestrogen content. Evidence of effects on multiple sclerosis (MS) is conflicting: risk may vary depending on the progestin used. Minor adverse effects may exist on inflammatory bowel diseases, and no significant effect was found on autoimmune thyroid diseases. Women can become sensitised to sex hormones. Progestin-only contraceptives may be used, although copper-releasing intra-uterine devices represent the best option. Finally, several organisations have issued guidelines for contraceptive use in women with AIDs.

Exposure to oral contraceptives increases the risk for development of inflammatory bowel disease: a meta-analysis of case-controlled and cohort studies

BACKGROUND

The oral contraceptive pill (OCP) is a widely used method of contraception. There have been conflicting studies linking the use of OCPs to the development of inflammatory bowel disease (IBD). The intent of this meta-analysis is to better define the association between OCP exposure and the risk for development of IBD.

METHODS

A thorough search of multiple databases, including Scopus, Cochrane, MEDLINE/PubMed, and CINAHL, and abstracts from major gastroenterology meetings was performed (October, 2016). Studies reporting the development of IBD in patients with or without previous exposure to OCP, compared with healthy controls, were included. A meta-analysis was completed using the Mantel-Haenszel model to evaluate the risk of developing IBD in the setting of previous OCP exposure.

RESULTS

In a complete analysis of 20 studies, there appeared to be over a 30% increased risk for the development of IBD in patients exposed to OCP compared with patients not exposed to OCP [odds ratio (OR): 1.32, 95% confidence interval (CI): 1.17-1.49, P<0.001, I=14%]. More specifically, there was a 24% higher risk for developing Crohn's disease (OR: 1.24, 95% CI: 1.09-1.40, P<0.001; I=38%) and a 30% higher risk for developing ulcerative colitis (OR: 1.30, 95% CI: 1.13-1.49, I=26%) in patients exposed to OCP compared with those not exposed to the medication.

CONCLUSION

The use of OCP is associated with an increased risk for development of Crohn's disease and ulcerative colitis in the genetically susceptible host. The total duration, dose of OCP exposure, and the risk for development of IBD need to be better characterized.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Smoking, breastfeeding, physical inactivity, contact with animals, and size of the family influence the risk of inflammatory bowel disease: A Slovak case-control study

BACKGROUND

The aetiology of inflammatory bowel disease (IBD) is not known but is likely to involve a combination of genetic predisposition and environmental risk factors. Smoking has been associated consistently with a higher risk of Crohn's disease (CD), while appendectomy and smoking appear to diminish the risk of ulcerative colitis (UC). The roles of other environmental factors are unclear. The aim of the present study was to evaluate the association of CD and UC with several environmental risk factors.

METHODS

This case-control study included 338 patients (190 CD, 148 UC) and 355 controls. All subjects completed a detailed questionnaire regarding breastfeeding duration, history of helminthic infections, allergic diseases, appendectomy, household size, housing type, contact with specific domestic animals, physical activity, and smoking. Associations between risk factors and CD and UC were investigated by univariate and multivariate analysis.

RESULTS

On multivariate analysis, CD associated with smoking at diagnosis (odds ratio, OR, 3.7, 95% CI 2.2-6.2; p < 0.001), being breastfed for <6 months (OR 2.7, 95% CI 1.7-4.4; p < 0.001), and less than two childhood sporting activities weekly (OR 2.7, 95% CI 1.5-5.0; p < 0.001) and inversely associated with frequent contact with cats in childhood (OR 0.6, 95% CI 0.4-0.9; p < 0.03). UC associated with less than two sporting weekly activities in childhood (OR 2.0, 95% CI 1.1-3.5, p = 0.02), fewer household members in childhood (OR 0.8, 95% CI 0.7-0.98, p = 0.03), and being breastfed for <6 months (OR 1.7, 95% CI 1.02-2.8, p = 0.04). A composite environmental risk index for CD revealed that 47 and 14% of the controls and patients with CD had no risk factors, respectively, and that 14 and 38% of the controls and patients with CD had at least two risk factors, respectively.

CONCLUSION

CD and UC associated with infrequent childhood sports activities and short breastfeeding. Furthermore, CD associated with smoking and infrequent contact with animals in childhood. UC associated with a smaller family size in childhood.

Oral contraceptives, reproductive factors and risk of inflammatory bowel disease

BACKGROUND

Oral contraceptive use has been associated with risk of Crohn's disease (CD) and ulcerative colitis (UC).

OBJECTIVE

To determine whether this association is confounded or modified by other important lifestyle and reproductive factors.

DESIGN

A prospective cohort study was carried out of 117,375 US women enrolled since 1976 in the Nurses Health Study I (NHS I) and 115,077 women enrolled since 1989 in the Nurses' Health Study II (NHS II) with no prior history of UC or CD. These women had provided information every 2 years, on age at menarche, oral contraceptive use, parity, menopause status and other risk factors. Diagnoses of CD and UC were confirmed by review of medical records. Cox proportional hazards models were used to calculate HRs and 95% CIs.

RESULTS

Among 232,452 women with over 5,030,196 person-years of follow-up, 315 cases of CD and 392 cases of UC were recorded through 2007 in NHS II and 2008 in NHS I. Compared with never users of oral contraceptives, the multivariate-adjusted HRs for CD were 2.82 (95% CI 1.65 to 4.82) among current users and 1.39 (95% CI 1.05 to 1.85) among past users. The association between oral contraceptives and UC differed according to smoking history (pheterogeneity=0.04). Age at menarche, age at first birth and parity were not associated with risk of UC or CD.

CONCLUSION

In two large prospective cohorts of US women, oral contraceptive use was associated with risk of CD. The association between oral contraceptive use and UC was limited to women with a history of smoking.

Endotoxin neutralization as a biomonitor for inflammatory bowel disease

Gram-negative bacterial endotoxin is a potent immunostimulant implicated in the development and/or progression of a variety of diseases. The mammalian immune system has both innate and adaptive immune responses to neutralize endotoxin. In this study, a system was developed to monitor bacterial exposure by measuring the extent and nature of endotoxin neutralization in plasma. In control patients, females had higher levels of endotoxin neutralization than males, mirroring clinical outcomes from bacterial infection and sepsis. In addition to the total amount of neutralization, we used inactivation techniques to elucidate the nature of this activity and develop a system to compare early and late immune responses. Using this method to monitor patients with inflammatory bowel disease, we found a more robust total response that relies more on long-term, adaptive components of the immune system and less on early, innate components. Our results indicate that endotoxin neutralization is a valuable method to discern inflammatory bowel disease patients from a control population. Additionally, the nature of neutralization may be valuable in monitoring disease severity and/or the role of medication.

Recent advances in understanding ulcerative colitis

Ulcerative colitis, one of the two main forms of inflammatory bowel disease, is characterized by inflammation of the large bowel with constant involvement of the rectum, and a possible continuous retrograde distribution up to the cecum. Typical macroscopic lesions are mucosal ulcerations, with immune cell infiltration and cryptic abscesses at histology. Ulcerative colitis usually manifests with bloody diarrhea, is associated with a number of extra-intestinal manifestations, and may be acutely complicated by toxic megacolon. Longstanding disease may predispose to the development of colorectal cancer. Therapeutic options include mesalazine, corticosteroids, immunomodulators and biologic agents; however, if these treatments fail, the only available therapeutic choice remaining is the surgical removal of the colon. This review emphasizes novel concepts in the basic aspects of ulcerative colitis, and, in addition to the current clinical and diagnostic knowledge, it also describes new treatment options for this condition.

Systematic evaluation of risk factors for diagnostic delay in inflammatory bowel disease

BACKGROUND

The diagnosis of inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), continues to present difficulties due to unspecific symptoms and limited test accuracies. We aimed to determine the diagnostic delay (time from first symptoms to IBD diagnosis) and to identify associated risk factors.

METHODS

A total of 1591 IBD patients (932 CD, 625 UC, 34 indeterminate colitis) from the Swiss IBD cohort study (SIBDCS) were evaluated. The SIBDCS collects data on a large sample of IBD patients from hospitals and private practice across Switzerland through physician and patient questionnaires. The primary outcome measure was diagnostic delay.

RESULTS

Diagnostic delay in CD patients was significantly longer compared to UC patients (median 9 versus 4 months, P < 0.001). Seventy-five percent of CD patients were diagnosed within 24 months compared to 12 months for UC and 6 months for IC patients. Multivariate logistic regression identified age <40 years at diagnosis (odds ratio [OR] 2.15, P = 0.010) and ileal disease (OR 1.69, P = 0.025) as independent risk factors for long diagnostic delay in CD (>24 months). In UC patients, nonsteroidal antiinflammatory drug (NSAID intake (OR 1.75, P = 0.093) and male gender (OR 0.59, P = 0.079) were associated with long diagnostic delay (>12 months).

CONCLUSIONS

Whereas the median delay for diagnosing CD, UC, and IC seems to be acceptable, there exists a long delay in a considerable proportion of CD patients. More public awareness work needs to be done in order to reduce patient and doctor delays in this target population.

Clinical characteristics of inflammatory bowel disease in Turkey: a multicenter epidemiologic survey

AIM

To investigate the epidemiologic and clinical characteristics of inflammatory bowel disease (IBD) patients in a large multicenter, countrywide, hospital-based study in Turkey.

MATERIALS AND METHODS

Twelve centers uniformly distributed throughout Turkey reported through a questionnaire the new IBD cases between 2001 and 2003. The incidence of ulcerative colitis (UC) and Crohn's disease (CD) has been reported per 100,000 people. Epidemiologic features and clinical characteristics of both diseases were analyzed.

RESULTS

During the study period, 661 patients of UC and 216 patients of CD were identified. The incidence in the referral population was 4.4/100,000 and 2.2/100,000 for UC and CD, respectively. The age of the patients showed the characteristic biphasic distribution with 2 peaks between 20 and 30 and 50 and 70 years. A male predominance was observed in both diseases. A history of smoking was detected in 15.5% of UC patients and 49.3% of patients with CD. Family history was positive in 4.4% in UC and 8.3% in CD patients. Concomitant amebiasis was observed in 17.3% of patients with UC and 1.3% of patients with CD. A history of appendectomy was reported in 15% of patients with CD and only 3% of patients with UC. Both extraintestinal and local complications were more frequent in CD patients, whereas arthritis was most common in both diseases.

CONCLUSIONS

IBDs are frequently encountered in Turkey. IBD incidence is lower than North and West Europe but close to Middle East in our country. The majority of IBD cases are diagnosed in young people (20 to 40 y) with predominance in males. The rate of both intestinal and extraintestinal complications in our population was low when compared with the data reported in the literature. IBD and especially UC, can coexist with amebiasis or become manifest with amebic infestation. The presence of concomitant ameba may create confusion and cause dilemmas in the diagnosis and treatment of UC.

The risk of oral contraceptives in the etiology of inflammatory bowel disease: a meta-analysis

OBJECTIVES

Several environmental and genetic factors have been implicated to date in the development of Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study was to provide a quantification of the risk of oral contraceptive pill (OCP) use in the etiology of inflammatory bowel disease.

METHODS

A literature search was performed to identify comparative studies reporting on the association of oral contraceptive use in the etiology of UC and CD between 1983 and 2007. A random-effect meta-analysis was used to compare the incidence of UC or CD between the patients exposed to the OCP and nonexposed patients. The results were adjusted for smoking.

RESULTS

A total of 75,815 patients were reported on by 14 studies, with 36,797 exposed to OCP and 39,018 nonexposed women. The pooled relative risk (RR) for CD for women currently taking the OCP was 1.51 (95% confidence interval [CI] 1.17-1.96, P= 0.002), and 1.46 (95% CI 1.26-1.70, P < 0.001), adjusted for smoking. The RR for UC in women currently taking the OCP was 1.53 (95% CI 1.21-1.94, P= 0.001), and 1.28 (95% CI 1.06-1.54, P= 0.011), adjusted for smoking. The RR for CD increased with the length of exposure to OCP. Moreover, although the RR did not reduce once the OCP was stopped, it was no longer significant once the OCP was stopped (CI contains 1), both for CD and for UC.

CONCLUSIONS

This study provides evidence of an association between the use of oral contraceptive agents and development of IBD, in particular CD. The study also suggests that the risk for patients who stop using the OCP reverts to that of the nonexposed population.

Environmental risk factors (excluding tobacco and microorganisms): critical analysis of old and new hypotheses

The increase in incidence in both ulcerative colitis and Crohn's disease during the 20th century has led to an abundance of different hypotheses on what sort of exposures are responsible. There has been a special focus on dietary factors, as well as on other exposures introduced on a population-based level, including fast food, cola drinks, toothpaste, antibiotics and oral contraceptives. The aim of this review is to critically assess the results from the different observational studies that have investigated these hypotheses, and also to propose research agendas that should be pursued in the future. The conclusion is that infectious exposures and early bacterial colonization, which are associated with better hygiene early in life and that influence immune function, and possibly oral contraceptives, remain the only exposures of interest for future research into the aetiology of ulcerative colitis and Crohn's disease.

Clinical epidemiology of inflammatory bowel disease: Incidence, prevalence, and environmental influences

Although the incidence and prevalence of ulcerative colitis and Crohn's disease are beginning to stabilize in high-incidence areas such as northern Europe and North America, they continue to rise in low-incidence areas such as southern Europe, Asia, and much of the developing world. As many as 1.4 million persons in the United States and 2.2 million persons in Europe suffer from these diseases. Previously noted racial and ethnic differences seem to be narrowing. Differences in incidence across age, time, and geographic region suggest that environmental factors significantly modify the expression of Crohn's disease and ulcerative colitis. The strongest environmental factors identified are cigarette smoking and appendectomy. Whether other factors such as diet, oral contraceptives, perinatal/childhood infections, or atypical mycobacterial infections play a role in expression of inflammatory bowel disease remains unclear. Additional epidemiologic studies to define better the burden of illness, explore the mechanism of association with environmental factors, and identify new risk factors are needed.

Inflammatory bowel disease and environmental influences

Some environmental factors have been established firmly as influences on the development of IBD, such as smoking and appendectomy. Other behaviors, such as oral contraceptive use and sugar intake, have been suggested as risk factors, but he data conflict sharply. The importance of other behaviors, such as breast-feeding, is even murkier with sharply divergent data. Some issues studied may not be factors in themselves but rather markers for other unidentified influences. The conflicting evidence in many of these studies may be clarified as specific genes are identified and the interplay between these environmental factors and genetic subtypes is investigated.

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 relationship between heritability and smoking habits in Crohn's disease. Italian Cooperative Study Group

OBJECTIVE

In Crohn's disease (CD), the relationship between genetic predisposition and smoking has not been well defined. The aim of this study was to compare the smoking habits at the time of the diagnosis of CD patients having familial occurrence of inflammatory bowel disease (IBD) with those of some control groups.

METHODS

In a multicenter study, 136 CD patients with a relative with IBD, 272 healthy controls matched for sex and age, 500 CD patients without familial occurrence of IBD, and 84 ulcerative colitis patients (UC) with familial occurrence of IBD were personally interviewed about their smoking habits. In addition, data for 35 healthy siblings of patients with familial CD were collected by interviewing the patients' relatives.

RESULTS

The prevalence of smokers was found significantly higher in CD patients with a family history for IBD than in healthy controls and in familial UC patients (OR 2.28 CI 1.5-3.48 and OR 5.81 CI 3.15-10.75, respectively). No significant difference was found either in the percentage of smokers or in the number of cigarettes smoked per day between familial and sporadic CD patients. Among all siblings of CD patients, 72% of affected siblings and 34% of healthy siblings were smokers, concordant with their relatives.

CONCLUSIONS

In CD patients with familial occurrence of IBD, the percentage of smokers is elevated. It is possible that in a genetically predisposed population, smoking could be an important environmental factor in determining CD or expressing this disease instead of UC.

Oral contraceptive use and smoking are risk factors for relapse in Crohn's disease. The Canadian Mesalamine for Remission of Crohn's Disease Study Group

BACKGROUND & AIMS

Lifestyle factors have been shown to influence prognosis in Crohn's disease. The purpose of this study was to prospectively assess the effects of smoking and oral contraceptive use on clinical relapse rates.

METHODS

Placebo-treated patients formed a prospective cohort, followed up for 48 weeks or until relapse. The influence of smoking and the use of oral contraceptives on relapse risk was examined by life-table analysis (log rank tests) and Cox proportional hazards modeling, taking into account demographic and disease characteristics.

RESULTS

Of 152 patients, 61 (40%) had a relapse. Univariate analysis showed unfavorable outcomes for women (P = 0.05), current smokers (P = 0.005), and use of oral contraceptives (P = 0.001). Recent surgery was associated with a decreased risk of relapse (P = 0.02). The Cox model retained current smoking vs. never smoking (hazard ratio, 2.1; 95% confidence interval, 1.1-4.2), oral contraceptive use (hazard ratio, 3.0; 95% confidence interval, 1.5-5.9), and medical compared with surgical induction of remission (hazard ratio, 2.1; 95% confidence interval, 1.0-4.2) as predictors of relapse. Ex-smokers did not have an increased risk. Finally, sex, age, time in remission, disease location, and disease duration were not significant predictors.

CONCLUSIONS

Oral contraceptive use and smoking are associated with an increased risk of relapse in patients with Crohn's disease.

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.

Meta-analysis of the role of oral contraceptive agents in inflammatory bowel disease

Numerous epidemiological studies have been performed to determine factors that might contribute to the development of inflammatory bowel disease. Although the role of oral contraceptive agents in Crohn's disease (CD) and ulcerative colitis (UC) have been assessed, most studies were of small sample size and characterised by low statistical precision. A meta-analysis was performed to increase the statistical power and to investigate the association between the use of oral contraceptives and the development of CD and UC. The study was based on a search of a Medline database from 1975 to October 1993 and a review of reference lists from published articles, reviews, symposia proceedings, and abstracts from major gastrointestinal meetings. All studies specifically designed to evaluate this association were selected. The combined results of nine studies--two cohort studies (30,379 unexposed and 30,673 exposed patients) and seven case-control studies (482 CD, 237 UC, and 3198 controls)--which satisfied our selection criteria were evaluated. The pooled relative risk (adjusted for smoking) associated with oral contraceptive use was 1.44 (1.12, 1.86) for CD and 1.29 (0.94, 1.77) for UC. These results suggest modest associations between the use of oral contraceptives and the development of CD and UC. As these associations are weak, non-causal explanations for the findings cannot be eliminated.