Underestimation of Smoking Rates in an East Asian Population with Crohn's Disease

[How Should We Do Different Approach to Treat Inflammatory Bowel Disease by Gender Difference?]

Although not as prominent, there are gender/sex differences in incidence/prevalence, clinical manifestation and disease course, comorbidities, therapeutic response, and patients coping strategy to the disease of inflammatory bowel disease (IBD). In this review, current knowledge about gender-specific differences in IBD would be provided and how to apply this in clinical practice be discussed.

Effects of smoking on the association of human leukocyte antigen with ulcerative colitis

BACKGROUND AND AIM

Tobacco smoking is a risk factor for gastrointestinal disorders, causing mucosal damage and impairing immune responses. However, smoking has been found to be protective against ulcerative colitis (UC). Human leukocyte antigen (HLA) is a major susceptibility locus for UC, and HLA-DRB1*15:02 has the strongest effect in Asians. This study investigated the effects of smoking on the association between HLA and UC.

METHODS

The study enrolled 882 patients with UC, including 526 never, 151 current, and 205 former smokers, and 3091 healthy controls, including 2124 never, 502 current, and 465 former smokers. Smoking-stratified analyses of HLA data were performed using a case-control approach.

RESULTS

In a case-control approach, HLA-DRB1*15:02 was associated with UC in never smokers (OR_{never smokers}  = 3.20, P_{never smokers}  = 7.88 × 10^-23 ) but not in current or former smokers (P_{current smokers}  = 0.72 and P_{former smokers}  = 0.33, respectively). In current smokers, HLA-DQB1*06 was associated with UC (OR_{current smokers}  = 2.59, P_{current smokers}  = 6.39 × 10^-12 ). No variants reached genome-wide significance in former smokers.

CONCLUSIONS

An association between UC and HLA-DRB1*15:02 was limited to never smokers. Our findings highlight that tobacco smoking modifies the effects of HLA on the risk of UC.

Smoking Status at Diagnosis and Subsequent Smoking Cessation: Associations With Corticosteroid Use and Intestinal Resection in Crohn's Disease

BACKGROUND

The impact of smoking at diagnosis and subsequent smoking cessation on clinical outcomes in Crohn's disease (CD) has not been evaluated in a population-based cohort.

METHODS

Using a nationally representative clinical research database, we identified incident cases of CD between 2005 and 2014. We compared the following outcomes: overall corticosteroid (CS) use; flares requiring CS; CS dependency and intestinal surgery between smokers and non-smokers at time of CD diagnosis. Differences in these outcomes were also compared between persistent smokers and smokers who quit within 2 years of diagnosis.

RESULTS

We identified 3553 patients with a new CD diagnosis over the study period of whom 1121 (32%) were smokers. Smokers at CD diagnosis had significantly higher CS-use (56 versus 47%, p < 0.0001), proportionally more CS flares (>1 CS flare/year: 9 versus 6%, p < 0.0001), and higher CS dependency (27 versus 21%, p < 0.0001) than non-smokers. Regression analysis identified smoking at diagnosis to be associated with a higher risk of intestinal surgery (HR 1.64, 95% CI 1.16-2.52). There was a significantly higher proportion of 'quitters' who remained steroid-free through follow-up in comparison to 'persistent smokers' (45.4 versus 37.5%, respectively, p = 0.02). 'Quitters' also had lower rates of CS dependency compared to 'persistent smokers' (24 versus 33%, p = 0.008).

CONCLUSIONS

Smokers at CD diagnosis have higher CS-use, CS dependency and higher risk of intestinal surgery. Quitting smoking appears to have beneficial effects on disease related outcomes, including reducing CS dependency highlighting the importance of offering early smoking cessation support.

Disease Activity Patterns Recorded Using a Mobile Monitoring System Are Associated with Clinical Outcomes of Patients with Crohn's Disease

BACKGROUND

Usefulness of a mobile monitoring system for Crohn's disease (CD) has not been evaluated. We aimed to determine whether disease activity patterns depicted using a web-based symptom diary for CD could indicate disease clinical outcomes.

METHODS

Patients with CD from tertiary hospitals were prospectively invited to record their symptoms using a smartphone at least once a week. Disease activity patterns for at least 2 months were statistically classified into good and poor groups based on two factors in two consecutive time frames; the degree of score variation (maximum-minimum) in each frame and the trend (upward, stationary, or downward) of patterns indicated by the difference in the mean activity scores between two time frames.

RESULTS

Overall, 220 (82.7%) and 46 (17.3%) patients were included in good and poor groups, respectively. Poor group was significantly more associated with disease-related hospitalization (p = 0.004), unscheduled hospital visits (p = 0.005), and bowel surgery (p < 0.001) during the follow-up period than good group. In the multivariate analysis, poor patterns [odds ratio (OR) 2.62, p = 0.006], stricturing (OR 4.19, p < 0.001) or penetrating behavior (OR 2.27, p = 0.012), and young age at diagnosis (OR 1.06, p = 0.019) were independently associated with disease-related hospitalization. Poor patterns (OR 4.06, p = 0.006) and an ileal location (OR 5.79, p = 0.032) remained independent risk factors for unscheduled visits. Poor patterns (OR 15.2, p < 0.001) and stricturing behavior (OR 9.77, p = 0.004) were independent risk factors for bowel surgery.

CONCLUSION

The disease activity patterns depicted using a web-based symptom diary were useful indicators of poor clinical outcomes in patients with CD.

Assessment of factors associated with smoking cessation at diagnosis or during follow-up of Crohn's disease

BACKGROUND AND AIM

Smoking cessation is known to improve the course of Crohn's disease (CD). However, the factors associated with smoking cessation after CD diagnosis have not been well established.

METHODS

Clinical characteristics and change in smoking status were evaluated in 445 current smokers at the time of CD diagnosis. Patients were classified into three subgroups based on their final smoking status and time of smoking cessation: non-quitters, quitters at diagnosis, and quitters during follow-up.

RESULTS

The overall smoking cessation rate was 55.7% (248 of 445 patients). The diagnosis of CD was the main reason for quitting (41.5%, 103 of 248 patients). Smoking cessation at the time of CD diagnosis was associated with intestinal resection within 3 months from CD diagnosis (odds ratio [OR] 2.355, 95% confidence interval [CI] 1.348-4.116, P = 0.003), light smoking (OR 2.041, 95% CI 1.157-3.602, P = 0.014), and initiation of smoking before 18 years of age (OR 0.570, 95% CI 0.327-0.994, P = 0.047). Light smoking (OR 1.762, 95% CI 1.019-3.144, P = 0.043) and initiation of smoking before 18 years (OR 0.588, 95% CI 0.381-0.908, P = 0.017) were also associated with overall smoking cessation.

CONCLUSION

Quitters after CD diagnosis, including quitters at diagnosis and quitters during follow-up, had features distinct from those of non-quitters. Given the motivation at CD diagnosis, a detailed history of smoking habits should be taken and all current smokers should be encouraged to quit smoking at the time of CD diagnosis.

Clinical characteristics and long-term prognosis of elderly onset ulcerative colitis

BACKGROUND AND AIM

The aim of this study was to investigate the clinical characteristics and prognosis of patients with elderly onset ulcerative colitis (EOUC), a new growing subgroup of UC.

METHODS

This study retrospectively analyzed 3060 South Korean UC patients diagnosed between 1977 and 2014. The clinical characteristics and prognosis of EOUC, defined as UC in those aged ≥ 60 years at diagnosis, were compared with those of non-EOUC (NEOUC).

RESULTS

Among the 3060 patients, 226 were diagnosed with EOUC (7.4%, median age at diagnosis 65.9 years [interquartile range, 62.9-68.7 years], 58.4% male). The frequency of EOUC increased from 3.9% in the interval 1977-1999 to 9.7% in the interval 2008-2014 (P < 0.001). There were more ex-smokers in the EOUC than in the NEOUC group (44.2% vs 19.9%, P < 0.001). In the EOUC group, extensive colitis at diagnosis, and the maximum extent thereof, was less than in the NEOUC group (13.7% vs 22.6%, P = 0.002, and 34.5% vs 42.5%, P = 0.011, respectively). The 10-year cumulative colectomy rate was significantly higher in the EOUC than in the NEOUC group (12.6% vs 7.7%, P = 0.015). UC-related and all-cause mortality were higher in the EOUC than in the NEOUC group (3.5% vs 0.6%, P < 0.001, and 12.4% vs 1.8%, P < 0.001, respectively).

CONCLUSION

Elderly onset ulcerative colitis patients are likely to exhibit distinct features both at diagnosis and during follow-up. It is necessary to pay more attention to, and to conduct further studies on, this particular group of patients.

Epidemiology, Natural History, and Risk Stratification of Crohn's Disease

Crohn's disease (CD) is a chronic condition that can result in significant morbidity and disability. By studying the association between demographics and initial clinical features and subsequent natural history, one may be able to stratify patients by their risks of clinical relapse, hospitalization, and surgery. Understanding the potential environmental risk factors and natural history of CD in a given patient guides the physician when counseling the patient and selecting a treatment strategy. In this review, updated data regarding the incidence and prevalence of CD, important environmental risk factors, natural history of the disease, and important prognostic factors are discussed.