Resumption Of Smoking Research Articles

Predictors of smoking relapse after percutaneous coronary intervention in Chinese patients.

To evaluate the prevalence and predictors of smoking relapse after percutaneous coronary intervention in Chinese patients. Smoking is considered a vital risk factor for coronary heart disease. Although smoking cessation could decrease the risks of adverse cardiac outcomes, many patients resume smoking following a short period of abstinence. However, little is known about smoking resumption in patients who have undergone percutaneous coronary intervention. A longitudinal study was conducted among Chinese patients who underwent percutaneous coronary intervention. Predictive variables were assessed at baseline through medical records and interviews with questionnaires including the Fagerström Test for Nicotine Dependence, Center for Epidemiologic Studies-Depression scale and Smoking Self-Efficacy Questionnaire. Smoking relapses were recorded at three, six, nine and 12months by the self-reporting through telephone or at routine visits to the cardiology outpatient clinics. A total of 221 patients who quit smoking immediately after percutaneous coronary intervention completed the whole study. Overall, 51.1%(n=113) of the patients relapsed within 12months after percutaneous coronary intervention. The prevalence showed a particular rise (49.6%, n=56) in the first 3months and a more gradual increase in the following months. The patients who were employed and had higher nicotine dependence, worse depressive symptoms and lower level of smoking self-efficacy were more vulnerable to relapse to cigarettes. The prevalence of smoking relapse is high in the patients who stop smoking in the hospital due to percutaneous coronary intervention. The predictors of smoking relapse are employment, nicotine dependence, depression and smoking self-efficacy in the post- percutaneous coronary intervention patients. This study may prompt the healthcare providers to focus on the issue of smoking relapse and provide some instructions for identification of the patients with a high-risk of relapse after percutaneous coronary intervention.

Event-related potentials reflecting smoking cue reactivity and cognitive control as predictors of smoking relapse and resumption.

RationaleGiven that most attempts to quit smoking fail, it is critical to increase knowledge about the mechanisms involved in smoking relapse and resumption (i.e., the increase in smoking over time after a quit attempt). Neurocognitive measures, such as event-related potentials (ERPs), may provide novel insights into smoking relapse and resumption.ObjectivesThe objective of the present study is to investigate the association between smoking relapse and resumption and ERPs reflecting smoking cue reactivity (i.e., P300, LPP), inhibitory control (i.e., N2, P3), and error processing (i.e., error-related negativity (ERN), Pe).MethodsSeventy-two smokers viewed smoking and neutral pictures and performed a Go-NoGo and an Eriksen Flanker task, while ERPs were measured using electroencephalography. All smokers started a quit attempt in the week following the laboratory visit. Smoking behavior after the quit attempt was measured at 4, 8, and 12 weeks. Both relapse (i.e., 7-day point prevalence at 12 weeks) and smoking resumption (i.e., the number of cigarettes a day at 4, 8, and 12 weeks) were used as outcome measures.ResultsLogistic regression analyses showed that smaller P3 amplitudes, reflecting brain activation associated with inhibitory control, are related to an increased relapse risk. Latent growth curve analyses showed that reduced post-error slowing, the main behavioral measure reflecting error processing, is associated with stronger smoking resumption. ERPs reflecting smoking cue reactivity were unrelated to smoking relapse or resumption.ConclusionsThe finding that smaller inhibitory control-related P3 amplitudes are associated with increased relapse risks suggests that strategies to increase inhibitory control in smokers are worth further investigation in the search for more effective smoking cessation interventions.Electronic supplementary materialThe online version of this article (doi:10.1007/s00213-016-4332-8) contains supplementary material, which is available to authorized users.

Tolerance and Effectiveness of Forced and Prolonged Smoking Cessation Among French Submariners.

This study investigates nicotine withdrawal symptoms and resumption rates of tobacco abuse among French submariners during and after a 7-week mission without using tobacco. A prospective study was conducted in 2010 during two missions aboard nuclear-powered ballistic missile submarines. Over a 6-month follow-up, the study subjects completed five standardized questionnaires (Fagerström test, Hospital Anxiety Depression, and the Minnesota Nicotine Withdrawal Scale). Out of 222 prospective study subjects, 168 were included, 52 of whom were smokers. For 84.9% of the smokers, the Fagerström test score was lower than 2 (no dependency). Additionally, 92% of the smokers did not experience withdrawal symptoms following an abrupt and mandatory cessation of cigarette smoking. Two-thirds of the smokers resumed their addiction within 2 months, 78% of whom did so the first day they had the opportunity. In the physically and mentally constraining environment of submarines, the behavioral component of cigarette dependency largely dominates over the psychological and physical components of nicotine dependence. This phenomenon occurs because the behavioral component of addiction is the source of smoking resumption and, therefore, must be better addressed to achieve sustained withdrawal.

Resumption of Smoking by Women after Childbirth: Influence of Spousal Smoking

To investigate factors related to resumption of smoking by women after childbirth, the smoking habits of 241 postnatal women, who initially had stopped smoking after pregnancy, in a rural city in Aomori Prefecture, Japan, were studied at 5 - 6 days, 1 month, and 12 months after childbirth. At 1 month after childbirth, only nine women had resumed smoking, but a total of 40 women had resumed smoking after 12 months. Factors related to smoking resumption after childbirth included the switching from breast feeding to bottle feeding and the influence of smoking by their spouses. Spousal smoking is an important factor in the resumption of smoking by women after childbirth.

Nondaily smokers' experience of craving on days they do not smoke.

Nondaily, or intermittent smokers (ITS), represent a growing pattern in adult smoking that needs to be explained by models of drug dependence. ITS regularly and voluntarily abstain from smoking, yet have difficulty quitting. We examine potential accounts of ITS' smoking by exploring their experience of craving and withdrawal on the days they abstain. For 3 weeks, 146 ITS and 194 daily smokers used the Ecological Momentary Assessment (EMA) to monitor craving, withdrawal, and smoking in real-time. ITS' craving (p < .001) and arousal (p < .001) were significantly lower on the 34.4% of days when they abstained (compared with days they smoked), and they experienced no increases in withdrawal symptoms. ITS who abstained for longer experienced lower craving, even on their first day of abstinence (p < .001). Within strata defined by longest duration of abstinence (1, 2-3, 4-6, ≥7 days), craving did not change over time, demonstrating no increase as resumption of smoking approached. Craving increased only at the moment smoking resumed. Furthermore, duration of abstinence runs varied more within persons than across persons. These findings contradict the predictions of a model positing that craving recurs at fixed intervals. Findings are consistent with the hypothesis that ITS' smoking is cued or primed by particular stimuli rather than by temporal cycles. These analyses demonstrate that ITS do not experience increased craving or withdrawal on days they do not smoke, and show neither signs of classical dependence nor regular cycles of craving and smoking.

Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention.

Acute nicotine administration stimulates [(14)C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus, and in right posterior cortical regions at this time. At 60 and 105 minutes after smoking resumption, CBF had increased by 8% and CMRO2 had increased by 11-12%. Thus, we find substantial and global impairment of CBF/CMRO2 in abstaining smokers, and acute restoration by resumption of smoking. The reduced CBF and CMRO2 during acute abstention may mediate the cognitive changes described in chronic smokers.

O063 Is a Heart attack really a wake up call? Rates and correlates of smoking cessation following PCI for Acute Coronary Syndrome (ACS)

R A L A B ST R who discontinued on the day of surgery. Fifty-one percent of current smokers resumed smoking in the year after surgery, with 80% of these resuming within 2 weeks. Conclusion: The timing of smoking cessation prior to surgery does not impact on cardiovascular, major medical outcomes or death in the perioperative period. Therefore, physicians seeing a patient even within 8 weeks of surgery should have no reservations about encouraging abstinence. Resumption of smoking after surgery is common and indicates that there are opportunities to encourage more sustained abstinence. Disclosure of Interest: None Declared A C T S O063

Reaching the unreached: Mobile surgical camps in a remote village of Himachal Pradesh.

Aims:The aim was to study the epidemiological factors responsible for pelvic organ prolapse (POP) in poor women of the remote village Shillai, do their POP quantification staging, to study the variety of surgeries conducted in mobile surgical camps in this area.Materials and Methods:Retrospective analysis of surgeries conducted in five mobile surgical camps in Shillai, Himachal Pradesh from 2009 to 2013, under “Project Prolapse”.Results:A total number of surgeries conducted in five camps from 2009 to 2013 were 490 including 192 gynecological surgeries. Eighty-two percent of gynecological surgery was conducted for POP. Poor nutritional status (mean weight 41.1 kg), multiparty (mean 3.5), early marriage (mean age 18.2 years), unassisted home deliveries (100%), premature bearing down (23.8%), early postpartum resumption of strenuous activity (54.7%) and smoking (33%) contribute to the high incidence of POP. Anterior compartment prolapse was seen in 99% of patients undergoing surgery while posterior compartment prolapse was seen in 4% of patients. Vaginal hysterectomy with anterior repair with culdoplasty was the most common procedure performed (73.4%), and vault suspension was done in 3.6% subjects. The complication rate was negligible.Conclusion:Uterovaginal prolapse is not only socially embarrassing and disabling; its surgical treatment is complex and costly too. The free mobile surgical camps under Project Prolapse in Shillai, Himachal Pradesh has provided relief to old neglected, disabled women suffering from prolapse in this remote village. Parallel counseling of women and dais for safe hospital delivery and training subordinates in prolapse surgery may help in addressing the problem of POP in this area in the long run.

Reassessing the Safety of Varenicline

Reassessing the Safety of Varenicline

Extended interactive voice response telephony (IVR) for relapse prevention after smoking cessation using varenicline and IVR: a pilot study

BackgroundThere is a significant resumption of smoking following smoking cessation using varenicline. Both smoking cessation medications and counseling have been shown to increase smoking quit rates at one year. Thus, the combination of varenicline and interactive voice response (IVR) telephony followed by extended IVR may further improve smoking cessation rates at one and two years.Methods101 participants were recruited from the community via newspaper advertisement. They attended a group counseling session and were given smoking information booklets from the Canadian Cancer Society.After 12 weeks of varenicline and 9 IVR calls, all participants who had quit smoking were randomized into 2 groups matched by levels of motivation and addiction as per baseline questionnaire score. The intervention group continued to receive bi-weekly IVR support for weeks 13 – 52. The control group no longer received IVR. The primary end-point was self-reported abstinence and exhaled carbon monoxide levels of less than 10 ppm for weeks 12, 52 and 2 years. Data were analyzed by Fisher’s exact test or Wilcoxon rank-sum test.ResultsOf the 101 participants, 44 (43%) had stopped smoking after 12 weeks of varenicline and 9 IVR calls. Of these, 23 (52%) were randomized to receive IVR calls from weeks 13 to 52.At 52 weeks, 26 (59%) participants remained smoke-free. Of the 23 with IVR, 12 (52.2%) stopped smoking compared to 14 of 21 (66.7%) without IVR. At 2 years, 40 of the 44 (90.9%) randomized participants were contacted and 24 of the 44 (54.5%) came in for testing. Fourteen (13% of the original cohort, 30% who were abstinent at 12 weeks and 53% who were abstinent at 52 weeks) remained smoke-free. Five of the 23 (21.7%) randomized to IVR and 9 of the 21 (42.9%) randomized to no IVR remained smoke-free at 2 years.ConclusionsIn this pilot study of an apparently healthy population, extended IVR did not affect abstinence rates. There was no relapse prevention benefit in offering 9 months of continued IVR to subjects who had stopped smoking after receiving 3 months of varenicline and IVR treatment.Trial registrationClinicalTrial.gov: NCT00832806

A dynamical systems approach to understanding self-regulation in smoking cessation behavior change.

Self-regulation, a key component of the addiction process, has been challenging to model precisely in smoking cessation settings, largely due to the limitations of traditional methodological approaches in measuring behavior over time. However, increased availability of intensive longitudinal data (ILD) measured through ecological momentary assessment facilitates the novel use of an engineering modeling approach to better understand self-regulation. Dynamical systems modeling is a mature engineering methodology that can represent smoking cessation as a self-regulation process. This article shows how a dynamical systems approach effectively captures the reciprocal relationship between day-to-day changes in craving and smoking. Models are estimated using ILD from a smoking cessation randomized clinical trial. A system of low-order differential equations is presented that models cessation as a self-regulatory process. It explains 87.32% and 89.16% of the variance observed in craving and smoking levels, respectively, for an active treatment group and 62.25% and 84.12% of the variance in a control group. The models quantify the initial increase and subsequent gradual decrease in craving occurring postquit as well as the dramatic quit-induced smoking reduction and postquit smoking resumption observed in both groups. Comparing the estimated parameters for the group models suggests that active treatment facilitates craving reduction and slows postquit smoking resumption. This article illustrates that dynamical systems modeling can effectively leverage ILD in order to understand self-regulation within smoking cessation. Such models quantify group-level dynamic responses in smoking cessation and can inform the development of more effective interventions in the future.

Smoking resumption after lung transplantation: standardised screening and importance for long-term outcome

To the Editor: Worldwide, about 40% of lung transplantations (LTx) are performed for end-stage emphysema [1]. Eligible patients are enrolled on the waiting list after at least 6 months of smoking cessation [1]. Although in most centres smoking behaviour after LTx is not routinely monitored, resuming smoking can complicate post-transplant outcome [2–5]. In general, smoking relapse can be found in 12–40% of all liver, heart and renal transplant patients [3]. Smoking is mostly assessed by use of a questionnaire. Only the study of Botha et al. [4] combined a questionnaire with urinary cotinine detection. We previously reported post-LTx smoking in 11% of our LTx patients [6]. Patients that restart smoking after heart [4] and liver transplantation [5] have an increased prevalence of cancer, yet there are no data for LTx. We assessed all living, mainly adult (98%), LTx patients (n=331, of whom 230 were also included in our previous study [5]) with a minimal follow-up of 1 year after approval by the local Ethics Committee (approval number S51577) and informed consent. Smoking behaviour was investigated by a questionnaire, semi-quantitative and quantitative measurement of cotinine, and exhaled carbon monoxide levels. The questionnaire addressed past and current smoking habits. Second-hand smoking was defined as an living with a relative who smoked. The exhaled carbon monoxide level was quantified using an electrochemical sensor (Bedfont Scientific, Kent, UK) (detection limit 1 ppm) as previously described [5]. An exhaled carbon monoxide value ≥10 ppm was considered positive. Quantitative cotinine analysis was …

System Identification Modeling of a Smoking Cessation Intervention

This paper examines the use of system identification to describe time-varying phenomena in a smoking cessation intervention. The analysis is facilitated by the availability of intensive longitudinal data that enables the application of system identification techniques. Two model structures are considered; one involves the concept of statistical mediation, while the other describes a feedback mechanism. In fitting these models to intensive longitudinal data from a University of Wisconsin clinical trial that studied bupropion and counseling as smoking cessation aids, we focus on the relationship between craving and smoking. Here, we find craving features inverse response and smoking behavior features a dramatic reduction on the quit date, followed by a resumption in smoking. Analyzing the resulting models, we find that they differ in how they describe smoking resumption, and the case is made that the feedback mechanism more appropriately describes the relationship between craving and smoking.

Effective secondary prevention through cardiac rehabilitation after coronary revascularization and predictors of poor adherence to lifestyle modification and medication. Results of the ICAROS Survey

Background and aimSecondary prevention is a priority after coronary revascularization. We investigate the impact of a cardiac rehabilitation (CR) program on lifestyle, risk factors and medication modifications and analyze predictors of poor behavioral changes and events in patients after coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). MethodsMulticenter (n=62), prospective, longitudinal survey in post-CABG or -PCI consecutive patients after a comprehensive CR program. Cardiac risk factors, lifestyle habits, medication and 1year cardiovascular events were collected. Logistic regression analyzed the association between risk factors, events and predictors of non-adherence to treatment and lifestyle. ResultsAt 1year, of the 1262 patients (66±10years, CABG 69%, PCI 31%), 94% were taking antiplatelet agents (vs. 91.8% at CR admission and 91.7% at CR discharge, p=ns), 87% statins (vs. 67.5%, p<.0001, and 86.3%, p=ns), 80.7% beta-blockers (vs. 67.4%, p<.0001, and 88.8%, p=ns), and 81.1% ACE inhibitors (vs. 57.5% p<.0001, and 77.7%, p=ns). 89.9% of the patients showed good adherence to treatment, 72% adhered to diet and 51% to exercise recommendations; 74% of smokers stopped smoking. Younger age was predictive of smoking resumption (OR 8.9, CI 3.5–22.8). Pre-event sedentary lifestyle (OR 3.3, CI 1.3–8.7) was predictive of poor diet. Older patients with comorbidity (OR 3.1; CI, 1.8–5.2) tended to persist in sedentary lifestyle and discontinue therapy and diet recommendations. Age, diabetes, smoking and PCI indication were predictors of recurrent CV events which occurred in 142 patients. ConclusionParticipation in CR results in excellent treatment after revascularization, as well as a good lifestyle and medication adherence at 1year and provides further confirmation of the benefit of secondary prevention. Several clinical characteristics may predict poor behavioral changes.

Associations between maternal stress and smoking: findings from a population‐based prospective cohort study

To investigate associations between maternal stress and smoking prior to, during and 6 months after the pregnancy. A prospective population-based cohort study. Norway. A total of 71 757 women in the Norwegian Mother and Child Cohort Study (MoBa) participating twice during pregnancy and at 6 months postpartum. Respondents' estimates of anxiety and depression, relationship discord and negative life events were measured, along with self-reports of smoking behaviour and demographic variables. Smoking was assessed at gestation weeks 17 and 30 and at 6 months postpartum. Of the 27.5% women who smoked at conception, 55.8% quit smoking during pregnancy. At 6 months postpartum, 28.9% of quitters had relapsed to smoking. In total, 12.9% of the sample reported smoking during the pregnancy. Adjusted for well-known risk factors, women reporting high levels of anxiety and depression had a decreased likelihood of quitting smoking during pregnancy [odds ratio (OR) 0.80, 95% confidence interval (CI): 0.73, 0.88) and an increased likelihood of relapsing after delivery (OR 1.26, 95% CI: 1.11, 1.44). Both relationship discord (OR 0.82, 95% CI: 0.75, 0.90) and exposure to negative life events (OR 0.93, 95%: CI 0.90, 0.96) had a negative influence on quitting smoking during pregnancy but had no influence on relapse to smoking postpartum. Maternal stress and relationship discord may inhibit smoking cessation during pregnancy and promote resumption of smoking after pregnancy in women who have achieved abstinence.

Relapse to Smoking and Postpartum Weight Retention Among Women Who Quit Smoking During Pregnancy

Postpartum weight retention contributes to obesity risk in women. Given that most women who quit smoking as a result of pregnancy will resume smoking within 6 months postpartum and that there is a robust association between smoking and weight, we sought to evaluate postpartum weight retention as a function of postpartum smoking status among women who had quit smoking during pregnancy. Women (N = 183) with biochemically confirmed cigarette abstinence at the end of pregnancy were recruited between February 2003 and November 2006. Women self-reported demographic information and weight before pregnancy. Smoking status and weight were documented at the end of pregnancy and at 6, 12, and 24 weeks postpartum. Breastfeeding was reported at 6 weeks postpartum. Differences in weight retention by relapse status at each assessment were evaluated. To examine weight retention in the presence of conceptually relevant covariates, mixed models with log-transformed weight data were used. At 24 weeks postpartum, 34.6% of women remained abstinent. Women who remained abstinent throughout the 24-week period retained 4.7 ± 2.1 kg more than did women who had relapsed by 6 weeks postpartum, P = 0.03. This difference in postpartum weight retention was significant after controlling for relevant covariates (age, race, breastfeeding, and pregravid BMI). Resumption of smoking within the first 6 weeks following childbirth is associated with decreased postpartum weight retention, even after controlling for breastfeeding and pregravid weight. Interventions to sustain smoking abstinence postpartum might be enhanced by components designed to minimize weight retention.

Acute cigarette smoking reduces latencies on a Smoking Stroop test

RationaleSensitivity to addiction-related cues, a type of attentional bias, may interfere with executive functions that are important in sustaining abstinence from drug abuse. Assessments of attentional bias in research participants who smoke cigarettes have used Smoking Stroop tasks, which are variations of emotional Stroop tasks in which the stimuli are smoking-related and neutral words. ObjectivesWe aimed to determine the effect of resumption of smoking by deprived cigarette smokers on attentional bias. MethodsTesting occurred twice on each of two test days. One test day began after overnight abstinence (13–16h) and the other after <1h of abstinence. The participants (n=51) smoked a cigarette between the two test sessions on each test day. ResultsSmokers exhibited attentional bias for smoking-related words and had longer response times after overnight abstinence than after brief abstinence. Cigarette smoking between sessions reduced response times on both test days with no interaction by stimulus type. ConclusionsSmoking-related cues have distracting effects in smokers, and smoking reduces response latency, with no specific effect on attentional bias. The increase in response speed may contribute to a smoker's impression that abstinence hinders performance and that smoking reverses impairment.

Low-dose smoking resumption in ex-smokers with refractory ulcerative colitis

Background and aimUlcerative colitis (UC) is primarily a disease of non-smokers. Ex-smokers may have a more refractory disease course and anecdotal evidence in non-controlled clinical trials have suggested that smoking resumption, or the administration of nicotine, may ameliorate signs and symptoms of UC in ex-smokers. We report outcomes of ex-smokers with refractory UC who resumed low-dose cigarette smoking. Methods17 ex-smokers with refractory UC were identified. Clinical remission was defined as a disease activity index score of 0. ResultsTwo out of 17 patients refused the recommendation to resume smoking. Of the 15 patients who resumed smoking, the mean daily number of cigarettes was 8.6. Fourteen out of those 15 patients who resumed smoking were able to maintain prolonged clinical remission off steroids. One out of the 15 patients failed to improve and required oral steroids. Another patient was compelled to quit smoking since he became addicted. His disease flared after maintaining a prolonged remission of 3years and he eventually underwent surgery. Three out of these 15 patients switched from cigarettes smoking to nicotine compounds and continued to maintain remission. ConclusionResumption of low dose smoking in a selected group of ex-smokers with refractory UC may ameliorate signs and symptoms. Quality of life, medication side effects, and smoking risk factors should all be considered and discussed with patients. Smokers should be meticulously followed for compliance with “low-dose” regimen and all associated smoking risks.

Bare Metal Stent Thrombosis in Patients With Acute Coronary Syndrome

Patients undergoing coronary stenting during acute coronary syndrome (ACS) are exposed to a higher risk of stent thrombosis (ST) than those undergoing elective stenting. FEW STUDIES HAVE AIMED TO IDENTIFY ST INCIDENCE AND PREDICTORS IN THIS SPECIFIC POPULATION. This single-center study enrolled 611 consecutive Tunisian patients with ACS who underwent coronary stenting with bare metal stents (BMS). The incidence of ARC (Academic Research Consortium) definite ST throughout a median 16-month follow-up period was 3.5%; it was 9.2% in patients with ST-elevation myocardial infarction (STEMI) who underwent an emergency percutaneous coronary intervention (PCI). Independent predictors were fever during PCI (hazard ratio (HR) 5.19; 95% confidence interval (95%CI) 1.69-15.95, P=0.004); premature cessation of clopidogrel (HR 2.66; 95%CI 1.02-6.97, P=0.046), resumption of smoking (after PCI) (HR 4.41; 95%CI 1.58-12.27, P=0.005), primary PCI (HR 5.02; 95%CI 1.57-16.01, P=0.006), rescue PCI (HR 6.33; 95%CI 2.08-19.34, P=0.001), reference vessel diameter <2.8mm (HR 6.96; 95%CI 2.06-23.56, P=0.002), TIMI flow grade before PCI <2 (HR 11.51; 95%CI 2.76-48.06, P=0.001) and a visible thrombus (HR 3.57; 95%CI 1.1-11.12, P=0.028). The incidence of ST in ACS patients was higher than classically described. Clopidogrel discontinuation and resumption of smoking are involved. Efforts should be made to improve patient education and secondary prevention.

Impact of environmental and dietary factors on the course of inflammatory bowel disease

Besides their possible effects on the development of inflammatory bowel disease (IBD), some environmental factors can modulate the clinical course of both ulcerative colitis (UC) and Crohn's disease (CD). This review is mainly devoted to describing the current knowledge of the impact of some of these factors on the outcome of IBD, with special emphasis on smoking and diet. Although the impact of smoking on the susceptibility to develop CD and UC is firmly established, its influence on the clinical course of both diseases is still debatable. In CD, active smoking is a risk factor for postoperative recurrence. Beyond this clinical setting, smoking cessation seems to be advantageous in those CD patients who were smokers at disease diagnosis, while smoking resumption may be of benefit in ex-smokers with resistant UC. The role of dietary habits on the development of IBD is far from being well established. Also, food intolerances are very frequent, but usually inconsistent among IBD patients, and therefore no general dietary recommendations can be made in these patients. In general, IBD patients should eat a diet as varied as possible. Regarding the possible therapeutic role of some dietary components in IBD, lessons should be drawn from the investigation of the primary therapeutic effect of enteral nutrition in CD. Low-fat diets seem to be particularly useful. Also, some lipid sources, such as olive oil, medium-chain triglycerides, and perhaps omega-3 fatty acids, might have a therapeutic effect. Fermentable fiber may have a role in preventing relapses in inactive UC.