David E. Ong

Environmental risk factors in inflammatory bowel disease: a population-based case-control study in Asia-Pacific.

Objective The rising incidence of inflammatory bowel disease in Asia supports the importance of environmental risk factors in disease aetiology. This prospective population-based case-control study in Asia-Pacific examined risk factors prior to patients developing IBD. Design 442 incident cases (186 Crohns disease (CD); 256 UC; 374 Asians) diagnosed between 2011 and 2013 from eight countries in Asia and Australia and 940 controls (frequency-matched by sex, age and geographical location; 789 Asians) completed an environmental factor questionnaire at diagnosis. Unconditional logistic regression models were used to estimate adjusted ORs (aOR) and 95% CIs. Results In multivariate model, being breast fed >12 months (aOR 0.10; 95% CI 0.04 to 0.30), antibiotic use (aOR 0.19; 0.07 to 0.52), having dogs (aOR 0.54; 0.35 to 0.83), daily tea consumption (aOR 0.62; 0.43 to 0.91) and daily physical activity (aOR 0.58; 0.35 to 0.96) decreased the odds for CD in Asians. In UC, being breast fed >12 months (aOR 0.16; 0.08 to 0.31), antibiotic use (aOR 0.48; 0.27 to 0.87), daily tea (aOR 0.63; 0.46 to 0.86) or coffee consumption (aOR 0.51; 0.36 to 0.72), presence of hot water tap (aOR 0.65; 0.46 to 0.91) and flush toilet in childhood (aOR 0.71; 0.51 to 0.98) were protective for UC development whereas ex-smoking (aOR 2.02; 1.22 to 3.35) increased the risk of UC. Conclusions This first population-based study of IBD risk factors in Asia-Pacific supports the importance of childhood immunological, hygiene and dietary factors in the development of IBD, suggesting that markers of altered intestinal microbiota may modulate risk of IBD later in life.

Early Course of Inflammatory Bowel Disease in a Population-Based Inception Cohort Study From 8 Countries in Asia and Australia

BACKGROUND & AIMS The incidence of inflammatory bowel disease (IBD) is increasing in Asia, but little is known about disease progression in this region. The Asia-Pacific Crohns and Colitis Epidemiology Study was initiated in 2011, enrolling subjects from 8 countries in Asia (China, Hong Kong, Indonesia, Sri Lanka, Macau, Malaysia, Singapore, and Thailand) and Australia. We present data from this ongoing study. METHODS We collected data on 413 patients diagnosed with IBD (222 with ulcerative colitis [UC], 181 with Crohns disease [CD], 10 with IBD unclassified; median age, 37 y) from 2011 through 2013. We analyzed the disease course and severity and mortality. Risks for medical and surgical therapies were assessed using Kaplan-Meier analysis. RESULTS The cumulative probability that CD would change from inflammatory to stricturing or penetrating disease was 19.6%. The cumulative probabilities for use of immunosuppressants or anti-tumor necrosis factor agents were 58.9% and 12.0% for patients with CD, and 12.7% and 0.9% for patients with UC, respectively. Perianal CD was associated with an increased risk of anti-tumor necrosis factor therapy within 1 year of its diagnosis (hazard ratio, 2.97; 95% confidence interval, 1.09-8.09). The cumulative probabilities for surgery 1 year after diagnosis were 9.1% for patients with CD and 0.9% for patients with UC. Patients with CD and penetrating disease had a 7-fold increase for risk of surgery, compared with patients with inflammatory disease (hazard ratio, 7.67; 95% confidence interval, 3.93-14.96). The overall mortality for patients with IBD was 0.7%. CONCLUSIONS In a prospective population-based study, we found that the early course of disease in patients with IBD in Asia was comparable with that of the West. Patients with CD frequently progress to complicated disease and have accelerated use of immunosuppressants. Few patients with early stage UC undergo surgery in Asia. Increasing our understanding of IBD progression in different populations can help optimize therapy and improve outcomes.

Addition of thiopurines can recapture response in patients with Crohn's disease who have lost response to anti-tumor necrosis factor monotherapy.

Anti‐tumor necrosis factor (TNF) antibodies are effective in maintaining remission in Crohns disease. However, a significant proportion of patients lose response to these agents with time. This study aimed to determine whether the introduction of a thiopurine in patients who have lost response to anti‐TNF monotherapy results in regained response.

Inflammatory bowel disease cancer surveillance in a tertiary referral hospital: attitudes and practice.

Physician adherence to guidelines for colorectal cancer (CRC) surveillance in inflammatory bowel disease (IBD) is often poor. This may lead to adverse patient outcomes and excess endoscopic workload.

Risk of Major Abdominal Surgery in an Asian Population-based Crohnʼs Disease Cohort

Background:Crohns disease (CD) is increasing in incidence and prevalence in Asia, but there is a paucity of population-based studies on risk factors for surgery in Asian patients with CD. This will be useful to identify patients who may benefit from top-down treatment. This study describes the rates of abdominal surgery and identifies associated risk factors in Singaporean patients with CD. Methods:This was a retrospective observational study. The medical records of Singaporeans diagnosed with CD from 1970 to 2013 were reviewed from 8 different hospitals in Singapore. The cumulative probability of CD-related abdominal surgery was estimated using the Kaplan–Meier method. The logistic regression model was used to assess associations between independent risk factors and surgery. Results:The cohort of 430 Singaporean patients with CD included 63.5% Chinese, 11.9% Malay, and 24.7% Indians, with a male to female ratio of 1.6; median follow-up was 7.3 years (range, 2.9–13.0 yr) and median age at diagnosis 30.5 years (range, 19.5–43.7 yr). One hundred twelve patients (26.0%) required major abdominal surgery: the cumulative risk of surgery was 14.9% at 90 days, 21.2% at 5 years, 28.8% at 10 years, 38.3% at 20 years, and 50.6% at 30 years from diagnosis. Of the surgical patients, 75.0% were Chinese, 10.7% Malays, and 14.3% Indians; 21.4% underwent surgery for inflammatory disease, 40.2% for stricturing disease, and 38.4% for penetrating disease. Age at diagnosis (A2 17–40 yr, OR: 2.75, 95% confidence interval [CI], 1.14–7.76), ileal disease (L1 location, OR: 2.35, 95% CI, 1.14–5.0), stricturing (B2 OR: 6.09, 95% CI, 3.20–11.8), and penetrating behavior (B3 OR: 21.6, 95% CI, 9.0–58.8) were independent risk factors for CD-related abdominal surgery. Indian patients were less likely to require surgery (OR: 0.40, 95% CI, 0.19–0.78). Conclusions:Age at diagnosis, L1 location, B2, and B3 disease behavior are independent risk factors for abdominal surgery. Interestingly, despite a higher prevalence of CD in Indians, a smaller proportion of Indian patients required surgery. These findings suggest that both environmental and genetic factors contribute to the risk of surgery in Asian patients with CD.

78 Incidence and Phenotype of Inflammatory Bowel Disease From 13 Countries in Asia-Pacific: Results From the Asia-Pacific Crohn's and Colitis Epidemiologic Study 2011-2013

Incidence and Phenotype of Inflammatory Bowel Disease From 13 Countries in Asia-Pacific: Results From the Asia-Pacific Crohns and Colitis Epidemiologic Study 2011-2013 Siew C. Ng, Gilaad Kaplan, Rupa Banerjee, Shu-Chen Wei, Whitney Tang, Zhirong Zeng, Min-hu Chen, Hong Yang, H. Janaka de Silva, Madunil A Niriella, David E. Ong, KhoonLin Ling, Ida Hilmi, Pises Pisespongsa, Satimai Aniwan, Julajak Limsrivilai, Murdani Abdullah, Vui Heng Chong, Qian Cao, Yinglei Miao, Arlinking K. Ong-Go, Sally Bell, Olga Niewiadomski, Michael A. Kamm, Ka Kei Ng, Hon Ho Yu, Yu-Fang Wang, Qin Ouyang, Khean Lee Goh, Hung-Hsin Lin, Wei-Chen Lin, Kaichun Wu, Marcellus Simadibrata, Francis K. Chan, Joseph Sung

Mo1993 Identification of Individuals at High Risk of Gastric Cancer for Targeted Endoscopic Screening

Identification of Individuals at High Risk of Gastric Cancer for Targeted Endoscopic Screening Zhu Feng, Li Lin Lim, Calvin J. Koh, David E. Ong, Lee Guan Lim, Khek-Yu Ho, Chia Chung-King, Christopher J. Khor, Choon Jin Ooi, Kwong Ming Fock, Jimmy B. So, Wee Chian Lim, Khoon-Lin Ling, Tiing Leong Ang, Andrew S. Wong, Jaideepraj Rao, Andrea Rajnakova, Ming Teh, Manuel Salto-Tellez, Supriya Srivastava, Yik Ying Teo, Khay Guan Yeoh

Population Density and Risk of Inflammatory Bowel Disease: A Prospective Population-Based Study in 13 Countries or Regions in Asia-Pacific

INTRODUCTION: Living in an urban environment may increase the risk of developing inflammatory bowel disease (IBD). It is unclear if this observation is seen globally. We conducted a population-based study to assess the relationship between urbanization and incidence of IBD in the Asia-Pacific region. METHODS: Newly diagnosed IBD cases between 2011 and 2013 from 13 countries or regions in Asia-Pacific were included. Incidence was calculated with 95% confidence interval (CI) and pooled using random-effects model. Meta-regression analysis was used to assess incidence rates and their association with population density, latitude, and longitude. RESULTS: We identified 1175 ulcerative colitis (UC), 656 Crohn’s disease (CD), and 37 IBD undetermined (IBD-U). Mean annual IBD incidence per 100 000 was 1.50 (95% CI: 1.43–1.57). India (9.31; 95% CI: 8.38–10.31) and China (3.64; 95% CI, 2.97–4.42) had the highest IBD incidence in Asia. Incidence of overall IBD (incidence rate ratio [IRR]: 2.19; 95% CI: 1.01–4.76]) and CD (IRR: 3.28; 95% CI: 1.83–9.12) was higher across 19 areas of Asia with a higher population density. In China, incidence of IBD (IRR: 2.37; 95% CI: 1.10–5.16) and UC (IRR: 2.63; 95% CI: 1.2–5.8) was positively associated with gross domestic product. A south-to-north disease gradient (IRR: 0.94; 95% CI: 0.91–0.98) was observed for IBD incidence and a west-to-east gradient (IRR: 1.14; 95% CI: 1.05–1.24) was observed for CD incidence in China. This study received IRB approval. CONCLUSIONS: Regions in Asia with a high population density had a higher CD and UC incidence. Coastal areas within China had higher IBD incidence. With increasing urbanization and a shift from rural areas to cities, disease incidence may continue to climb in Asia.

The association between new generation oral contraceptive pill and the development of inflammatory bowel diseases

Background/Aims To examine the association between use of oral contraceptive pills (OCPs) and the risk of developing inflammatory bowel diseases (IBD), in a modern cohort. Methods A prospective nested case-control study across sites in the Asia-Pacific region was conducted; involving female IBD cases and asymptomatic controls. Subjects completed a questionnaire addressing questions related to OCP use. Primary outcome was the risk of development of IBD of those exposed to OCP versus non-exposure. Secondary outcomes were development of Crohns disease (CD) versus ulcerative colitis (UC), and whether age of first use of OCP use may be associated with risk of IBD. Results Three hundred and forty-eight female IBD cases (41% CD, median age: 43 years) and 590 female age-matched controls were recruited. No significant association was found between OCP use and the risk of IBD (odds ratio [OR], 1.65; 95% confidence interval, 0.77–3.13; P=0.22), CD (OR, 1.55) or UC (OR, 1.01). The lack of association persisted when results were adjusted for age and smoking. IBD cases commenced OCP use at a younger age than controls (18 years vs. 20 years, P=0.049). Conclusions In this large cohort of subjects from the Asia-Pacific region, we found a modest but not significantly increased risk of developing IBD amongst OCP users.

Endoscopic and Histological Mucosal Healing in Ulcerative Colitis in the First Year of Diagnosis: Results from a Population-based Inception Cohort from Six Countries in Asia

Background and Aims Mucosal healing is associated with improved long-term clinical outcomes in patients with ulcerative colitis. This population-based study assessed endoscopic and histological mucosal healing within the first year of diagnosis. Methods Consecutive patients diagnosed with ulcerative colitis from six countries in Asia were prospectively enrolled. Clinical demographics, blood markers and inflammatory activity were assessed at baseline. Mayo score and Nancy index were used to assess endoscopic and histological activities, respectively. Clinical, endoscopic and histological evaluations were repeated at 1 year. Logistic regression was performed to identify predictors of mucosal healing. Results Of 433 ulcerative colitis patients, 202 [46.7%] underwent colonoscopy at 1 year. In total, 68 [38.2%] achieved endoscopic mucosal healing and 35 [23.1%] achieved histological mucosal healing. On multivariate analysis, an elevated erythrocyte sedimentation rate [ESR] at diagnosis (odds ratio [OR], 0.332; 95% confidence interval (CI), 0.133-0.830; p = 0.018) was a significant negative predictor of endoscopic mucosal healing at 1 year, while histological features of ulceration [OR, 0.156; 95% CI, 0.028-0.862; p = 0.033] and being an ex-smoker [OR, 0.067; 95% CI, 0.005-0.965; p = 0.047] were significant negative predictors of histological healing at 1 year. Both endoscopic and histological mucosal healing were associated with less steroid use [p < 0.001 and p = 0.001, respectively] and hospitalization [p = 0.002 and p = 0.01, respectively]. Conclusions Mucosal healing was achieved in fewer than half of patients with ulcerative colitis in the first year of diagnosis. An elevated ESR predicted less likelihood of endoscopic mucosal healing, while histological features of ulceration and being an ex-smoker at diagnosis predicted less likelihood of histological healing.