A28 RELATIVE RATES OF ULCERATIVE COLITIS TO CROHN’S DISEASE: PARALLEL EPIDEMIOLOGIES IN NEWLY VS. HIGHLY INDUSTRIALIZED COUNTRIES

Background

Inflammatory bowel disease (IBD) first presents in a population as cases of ulcerative colitis (UC) followed by cases of Crohn’s disease (CD). Newly industrialized countries (NIC) show a prallel epidemiology of IBD to highly industrialized countries (HIC) in the previous century; one marker of this is the relative incidence/prevalence rates of UC to CD, which approximates 1 over time.

Aims

Provide evidence for the UC:CD ratio as a proxy for disease penatrance in a population.

Methods

Systematic review of MedLine and Embase for studies reporting incidence or prevalence of UC and CD. Log-linear regression (by region and NIC/HIC [2019 United Nations definitions]) was used to calculate average annual percent change (AAPC) and associated 95% confidence intervals (CI). Data were plotted on an online, interactive map to show trends (link provided).

Results

We extracted data from 218 studies compising population-level data from 69 countries. We found negative AAPCs as the prevalence ratio of UC:CD significantly decreased over time in East Asia, West Asia, North Europe, and South Europe; 6/12 global regions displayed significantly decreasing incidence ratios. No AAPC was found to be significantly increasing (Table 1). When examing HIC/NIC, we found a significant effect of NIC on the UC:CD prevalence ratio after 2000 (AAPC:−3.83;95%CI:−6.28,−1.31) while HIC regions remained stable (AAPC:2.14;95%CI:−1.40,5.82). Looking at all available data, both HICs and NICs show significantly decreasing UC:CD prevalence ratios (HIC:AAPC:−3.72;95% CI:−4.46,−2.97; NIC:AAPC:−2.62;95%CI:−4.13,−1.08).

Conclusions

In some HICs (eg. Canada), the UC:CD incidence ratio was <1 in the earliest available data (1966), explaining the stable AAPC in North America (AAPC:−0.24;95%CI:−1.12,0.65). However, in NICs (eg. Southern Asia), the AAPC is rapidly decreasing (AAPC:−24.68;95%CI:−37.85,−8.71) as areas like Sri Lanka rapidly fall from an incidence ratio of 7.5 (2007) to 2.8 (2012), mimicking trends in IBD epidimeology of HICs in the previous century.

Funding Agencies

None

Disability in Restorative Proctocolectomy Recipients Measured using the Inflammatory Bowel Disease Disability Index

BACKGROUND AND AIMS

The inflammatory bowel disease [IBD] disability index [IBD-DI], which measures IBD-associated disability, has been validated on IBD patients but not those who have had restorative proctocolectomy with ileal pouch-anal anastomosis [RP with IPAA]. This study aimed to utilize the IBD-DI in RP with IPAA recipients and compare ulcerative colitis [UC]-indicated RP with IPAA patients to medically treated UC patients.

METHODS

This study was population based. Demographic, indication, complication and direct cost data were collected via medical records while disability, quality of life [QoL] and indirect costs were measured using questionnaires and structured interviews. De-identified raw data about medically treated UC patients were provided by a previous study for comparison.

RESULTS

In total there were 136 RP with IPAA patients [mean 11.5 years of follow up]. Eighty-four completed the IBD-DI and 80 completed the IBD questionnaire [IBDQ]. The IBDQ and IBD-DI were highly correlated [r = 0.84, p < 0.01]. Worse QoL and disability were found in those who had their position affected at work [both p < 0.01] and those who had more than 100 days off work in the last year [p < 0.01 for QoL and p = 0.012 for disability]. Lower QoL and disability scores were associated with higher indirect and total costs [p < 0.01]. UC patients treated with RP with IPAA had less disability than medically treated UC patients [p = 0.04].

CONCLUSIONS

Disability in RP with IPAA recipients can be measured using the IBD-DI. Perioperative complications and high costs of care are associated with higher levels of disability. Disability of RP with IPAA recipients was lower than that of medically managed UC patients.

In vitro characterisation of the fermentation profile and prebiotic capacity of gold-fleshed kiwifruit

A new Actinidia chinensis gold-fleshed kiwifruit cultivar 'Zesy002' was tested to investigate whether it could positively modulate the composition of the human colonic microbiota. Digested Zesy002 kiwifruit was added to in vitro pH-controlled anaerobic batch fermenters that were inoculated with representative human faecal microbiota. Alterations to the gut microbial ecology were determined by 16S rRNA gene sequencing and metabolic end products were measured using gas chromatography and liquid chromatography - mass spectrometry. Results indicated a substantial shift in the composition of bacteria within the gut models caused by kiwifruit supplementation. Zesy002 supplemented microbiota had a significantly higher abundance of Bacteroides spp., Parabacteroides spp. and Bifidobacterium spp. after 48 h of fermentation compared with the start of the fermentation. Organic acids from kiwifruit were able to endure simulated gastrointestinal digestion and were detectable in the first 10 h of fermentation. The fermentable carbohydrates were converted to beneficial organic acids with a particular predilection for propionate production, corresponding with the rise in Bacteroides spp. and Parabacteroides spp. These results support the claim that Zesy002 kiwifruit non-digestible fractions can effect favourable changes to the human colonic microbial community and primary metabolites, and demonstrate a hitherto unknown effect of Zesy002 on colonic microbiota under in vitro conditions.

Canterbury Health, Ageing and Life Course (CHALICE) study: rationale, design and methodology

AIMS

New Zealand's ageing population threatens the financial sustainability of our current model of health service delivery. The Canterbury Health, Ageing and Life Course (CHALICE) study aims to develop a comprehensive and flexible database of important determinants of health to inform new models. This paper describes the design, methodology, and first 300 participants of CHALICE.

METHODS

Commencing August 2010, CHALICE is a multidisciplinary prospective random cohort study and biobank of 1,000 Canterbury adults aged 49-51 years at inception, stratified by self-identified Maori (n=200) and non-Maori (n=800) ethnicity. Assessment covers sociodemographic, physical, cognition, mental health, clinical history, family and social, cardiovascular, and lifestyle domains. Detailed follow-up assessment occurs every 5 years, with a brief postal follow-up assessment undertaken annually.

RESULTS

For the first 300 participants (44 Maori, 256 non-Maori), the participation rate is 63.7%. Overall, 53.3% of participants are female, 75.3% are living in married or de facto relationships, and 19.0% have university degrees. These sociodemographic profiles are comparable with the 2006 Census, Canterbury region, 50-54 years age group percentages (50.7%, 77.2%, and 14.3%, respectively).

CONCLUSIONS

CHALICE has been designed to provide quality data that will inform policy development and programme implementation across a broad spectrum of health indicators.

Ileal disease is associated with surgery for perianal disease in a population-based Crohn's disease cohort

BACKGROUND

The aim of this study was describe the frequency and characteristics of perianal surgical intervention (PSI) for Crohn's disease in a population-based cohort of patients with inflammatory bowel disease (IBD).

METHODS

A total of 1421 patients with IBD were recruited, representing approximately 91 per cent of people with IBD in Canterbury, New Zealand. The clinical notes were screened to confirm the diagnosis and extract clinical data, including details of PSIs.

RESULTS

Some 649 patients with Crohn's disease were included in the analysis, of whom 119 (18.3 per cent) had at least one PSI. Of these, 61 (51.3 per cent) required further procedures. Operations for perianal abscess and fistula accounted for 72.4 per cent of interventions. PSI rates did not differ between the sexes (P = 0.218). Age less than 17 years (adjusted odds ratio (OR) 1.89 (95 per cent confidence interval 1.08 to 3.28)) and ileal disease (OR 1.76 (1.06 to 2.92)) were identified as predictors of PSI. As disease duration increased, so did the proportion of patients with complicated intestinal disease among those who had undergone PSI. The median time to first PSI from diagnosis of Crohn's disease was 28 (interquartile range 7-82) months. Sex, age at diagnosis and disease location did not influence the time to first PSI.

CONCLUSION

PSIs are frequent in patients with Crohn's disease, particularly those with ileal disease and those diagnosed at a young age.

Quantifying exposure to diagnostic medical radiation in patients with inflammatory bowel disease: are we contributing to malignancy?

BACKGROUND

While potential risks of diagnostic medical radiation are acknowledged, actual exposure of patients in routine clinical practice is poorly documented.

AIM

To quantify such exposure to vulnerable abdominal organs in patients with inflammatory bowel disease who are already at risk of intestinal cancer.

METHODS

All incidences of exposure to diagnostic medical radiation were documented in a consecutive series of 100 patients with inflammatory bowel disease (62 Crohn's disease, 37 ulcerative colitis, 1 indeterminate colitis) attending a hospital-based clinic. Total effective dose (mSv) was calculated using published tables. Predictors of high or no irradiation were evaluated by multivariate logistic regression analysis.

RESULTS

Thirteen patients had no documented diagnostic irradiation. Twenty-three patients received an effective dose greater than 25 mSv. An at-risk effective dose >50 mSv was received by 11 patients. Dosage was higher in patients with Crohn's disease than ulcerative colitis (P = 0.02) and in patients undergoing surgery (P = 0.004). However, no predictive factors for high radiation dosage or for no exposure were identified.

CONCLUSIONS

At-risk irradiation from diagnostic medical radiation is common in patients with inflammatory bowel disease, and might potentially contribute to the elevated risk of intra-abdominal and other cancers. The level of irradiation should be considered in clinical decisions regarding abdominal imaging.