Steve Tsang

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.

Natural History of Elderly-onset Ulcerative Colitis: Results from a Territory-wide Inflammatory Bowel Disease Registry

BACKGROUND AND AIMS Data on the natural history of elderly-onset ulcerative colitis [UC] are limited. We aimed to investigate clinical features and outcomes of patients with elderly-onset UC. METHODS Patients with a confirmed diagnosis of UC between 1981 and 2013, from 13 hospitals within a territory-wide Hong Kong Inflammatory Bowel Disease Registry, were included. Clinical features and outcomes of elderly-onset patients, defined as age ≥ 60 years at diagnosis, were compared with those of non-elderly-onset disease [< 60 years at diagnosis]. RESULTS We identified 1225 patients, of whom 12.8% [157/1225; 56.1% male] had elderly-onset UC. Median duration of follow-up was 11 years [interquartile range, 6-16 years]. Age-specific incidence of elderly-onset UC increased from 0.1 per 100000 persons before 1991 to 1.3 per 100000 persons after 2010. There were more ex-smokers [32.2% vs. 12.2%, p < 0.001] and higher proportion of comorbidities [p < 0.001] in elderly-onset than non-elderly-onset patients. Disease extent, corticosteroids, immunosuppressants use, and colectomy rates were similar between the two groups. Elderly-onset disease was an independent risk factor for cytomegalovirus infection [odds ratio 2.9, 95% confidence interval 1.6-5.2, p < 0.001]. More elderly-onset patients had Clostridium difficile infection [11.0% vs. 5.4%, p = 0.007], hospitalisation for UC exacerbation [50.6% vs. 41.8%, p = 0.037], colorectal cancer [3.2% vs. 0.9%, p = 0.033], all-cause mortality [7.0% vs. 1.0%, p < 0.001], and UC-related mortality [1.9% vs. 0.2%, p = 0.017] than non-elderly-onset patients. CONCLUSIONS Elderly-onset UC patients are increasing in number. These patients have higher risk of opportunistic infections, hospitalisation, colorectal cancer, and mortality than non-elderly-onset patients. Management and therapeutic strategies in this special group need careful attention.

Su1303 Prevalence and Disease Characteristics of Inflammatory Bowel Disease (IBD) in Chinese: Results From a Nationwide Population-Based Registry

Prevalence and Disease Characteristics of Inflammatory Bowel Disease (IBD) in Chinese: Results From a Nationwide Population-Based Registry Siew C Ng, Wai K. Leung, Michael K. Li, Chi Man Leung, Yee Tak HUI, Carmen Ka Man Ng, Fu Hang Lo, Steve Tsang, Ching Kong Loo, Yiu Kay Chan, Kam Hon Chan, Aric J. Hui, Wai Hung Chow, Jessica Ching, Tiffany ML Chung, Catherine YY Iu, Marcus Harbord, Ivan Fan Ngai Hung, Wai Cheung Lao, Shun Fung Sze, Marc Tin Long Wong, Rita Leung, Vivian W. Tsang, Belsy Chung Yan Lam, Raymond Wai Hung Tong, Edwin Hok Shing Shan, Lai Yee Mak, Sai Ho Wong, Justin C. Wu, Francis K. L. Chan, Joseph J. Y. Sung

Su1301 Incidence and Phenotype of Inflammatory Bowel Disease From 2012-2013 Across 9 Countries in Asia: Results From the 2012 Access Inception Cohort

AGA Poster session Abstract (Su1301) Digestive Disease Week (DDW), May 16-19, 2015, Washington DC

219 Incidence and Phenotype At Diagnosis of Inflammatory Bowel Disease Across 9 Countries in Asia-Pacific

Whether the results of randomized controlled trials on colorectal cancer (CRC) screening with guaiac fecal occult blood test (gFOBT) are transposable in the real world is questionable. gFOBT has several drawbacks, one is the requirement for frequent testing, which may limit compliance and thereby effectiveness. Aim: To assess the short term outcomes of the four first rounds of a population-based CRC screening program using gFOBT. Methods: Comparison of the outcomes of the four first rounds (R1 to R4) of the organized CRC screening program with Hemoccult II implemented in the Haut-Rhin, a French administrative area, since 2003 (Denis B et al Gut 2007;56:1579-84). All average-risk residents aged 50 74 were invited by mail to participate every other year. Results: Main outcomes are presented in the table. The crude uptake rate decreased from 47.9% to 38.5%. The decrease in adjusted uptake was similar in men and women but was observed in younger age groups (50 64) only and maximal in the 50 54 year age group. 15.8% of people who participated in Rn did not participate in Rn+1. Overall, 56.7% of the target population had completed at least one test and 19.6% four tests. More than 80% of the completed tests were provided by general practitioners. The positive predictive value for advanced neoplasia decreased significantly from 31.4% in R1 to 26.1% in R4 (and detection rate from 9.7‰ to 4.7‰). The rate of stage I colon cancers decreased significantly from 44.9% in R1 to 38.1% in R4. Conclusion: Participation and yield deteriorated with time in our organized population-based gFOBT CRC screening program. This deterioration was not observed in previous randomized controlled trials on gFOBT screening and may question the reproducibility of their effectiveness on the reduction of CRC mortality in the real world. Effort is needed to enhance uptake and to reduce inequalities in participation related to sex, age, place of residence and deprivation.