Epidemiology of IBD: the most relevant epidemiological abstracts at ECCO’22

1. The rising prevalence of IBD

A number of the presented epidemiological studies highlighted the constant rise in the global incidence and prevalence of IBD despite continuing advances in the diagnostic and management tools available to prevent and treat the disease.

DOPO2: K. Kontola and colleagues from Tampere University Hospital, Finland, studied the records obtained from the Social Insurance Institution of Finland. They showed that the crude annual incidence of CD increased from 7.5 per 100,000 in the year 2000 to 13.4 per 100,000 in 2020, yielding a significant 1.02-fold increase in the incidence of CD. The same trend was observed for UC – from 20.4 to 34.7 per 100,000 – leading to a 1.03-fold increase in the incidence of UC. During this period, 42,498 new IBD cases were identified. The crude prevalence of IBD increased very significantly, from 376 to 972 per 100,000, with a prevalence risk ratio of 1.05 (CI 1.046–1.047). The study concluded that the incidence of UC and CD continues to increase, with almost one percent of the Finnish population having IBD during the first two decades of the twenty-first century.

P653: The same trend was reported by M. Agrawal and colleagues from Icahn School of Medicine at Mount Sinai, NY, United States. Using data obtained from the Danish Civil Registration System (CRS) and the National Patient Registry (NPR) of all residents in Denmark between 1995 and 2018, they showed that 52,407 individuals were diagnosed with IBD, comprising 17,355 (33%) with CD and 35,052 (67%) with UC. The overall incidence rose significantly from 9.2 to 18 per 100,000 person-years for CD, corresponding to a 94.9% increase, and from 21.1 to 28.4 per 100,000 person-years for UC, corresponding to a 34.1% increase. The prevalence increased by 225.6% and 218.4% for CD and UC, respectively. The fact that the incidence of CD and UC is still increasing calls for more preparation for the management of the IBD population, especially the elderly.

P680: E.S. Zagórowicz and colleagues from Maria Sklodowska-Curie Memorial Cancer Center, Warsaw, Poland, presented similar results. They evaluated administrative health claims collected between 2009 and 2020 and estimated a prevalence of 61.6 and 191.4 per 100,000 people for CD and UC, respectively. Over the period 2012–2018, the prevalence of CD and UC increased significantly. They concluded that a substantial increase in the disease prevalence and burden has been observed in the past decade.

P690: Beyond the EU region, another study by M. Qiu and colleagues from New Zealand showed a clear ethnic-specific and consistent increasing trend in the incidence of IBD from 2001 to 2020, confirming the findings from previous studies from New Zealand, including in the local Māori population.

Viewing these studies in conjunction, the message is clear: the prevalence and incidence of IBDs are rising even in Western countries and especially in the elderly. Older adults are the fastest-growing subpopulation of patients with IBD.

2. New risk factors for IBD

Several studies focused on the identification of new risk factors for IBD, and I report on the two strongest studies here.

DOP06: A. Faye and colleagues from NYU Langone Health, New York, United States, studied a cohort of residents ≥60 years of age between 2000 and 2018, obtained from the Denmark nationwide registries and the Danish National Patient Register. Among 2,327,796 people in this cohort (with 22,670,484 person-years of follow-up), 10,773 new cases of UC and 3825 new cases of CD were identified. A positive history of antibiotic use was associated significantly with a 1.64-fold increase in the incidence of IBD, accompanied by a positive dose response. Interestingly, the highest risk was for use of antibiotics just 1–2 years prior to diagnosis.

P655: With the infectious and the hygiene hypothesis on the risk of IBD as their starting point, M. Agrawal and colleagues from Icahn School of Medicine at Mount Sinai, New York, United States, examined the impact of exposure to mebendazole during childhood and adolescence on the risk of IBD. They used the historical data of 1,520,290 people born between 1995 and 2018, obtained from the Danish National Registers and the National Prescription Registry. Mebendazole exposure at age <5 years was associated with a 1.32-fold increased risk of adult-onset UC, which emphasises the importance of early-life exposures in shaping the risk of IBD later in life.

3. Comorbidity of IBD with other diseases

DOP01: A multicentre study by B. Hayee and colleagues from King’s College Hospital, London, showed that 64.7% of 252 patients with moderate-to-severe psoriasis had one or more indicators of IBD risk at the time of diagnosis, while 3.6% had a confirmed diagnosis of IBD. Prospective investigations will report on the treatments for the identified “at risk” cohort.

P664: Likewise, D.H. Kim and colleagues from Yung Hee University Hospital Department of Paediatrics, Dongdaemun-gu, Republic of Korea, analysed the data of 2,347,591 people from the Korean National Health Insurance claims database who represent the birth cohort from 2002 to 2006. They evaluated data up to 2019. While a total of 2444 IBD patients and 5165 psoriasis patients were identified, 13 patients had both IBD and psoriasis; this translates into a 2.4 odds ratio for observation of psoriasis in IBD patients compared to the control population among paediatric patients.

DOP05: F.C. Canete Pizarro and colleagues, from Germans Trias i Pujol University Hospital, Barcelona, used the Catalan Public Health System database to identify 7.7 million inhabitants (in 2021) who had obesity or morbid obesity within the period 2005–2020. They found 4277 new diagnoses of IBD and determined that the likelihood of developing IBD was significantly higher in patients with morbid obesity as compared with obese patients, with an HR of 1.46. Morbid obesity is an independent risk factor for both CD and UC.

P684: On the same comorbidity track, A.M. Sleutjes and colleagues, from Erasmus Medical Centre, Rotterdam, the Netherlands, assessed the risk of cardiovascular disease (CVD) in IBD patients in a cross-sectional study of 235 consecutive IBD patients aged ≥45 years. They found that, compared with 829 matched controls, IBD patients were more frequently diagnosed with CVD [odds ratio (OR) 2.01], more frequently used antihypertensive drugs (OR 1.67), had a 4 cm larger waist circumference and had a 0.6 mmol/L higher triglyceride level. The CVD risk profile in IBD patients was characterised by hypertension, truncal obesity and hypertriglyceridaemia, particularly among male IBD patients.

P687: R. Loveikyte and colleagues from Leiden University Medical Center, Leiden, the Netherlands, evaluated 2197 patients for the presence of iron-deficiency anaemia and its potential risk factors in a Dutch outpatient population collected across 16 general academic hospitals in the Netherlands. The showed that the prevalence of anaemia, iron-deficiency anaemia and iron deficiency was 18.0%, 12.2% and 43.4%, respectively. Unlike disease clinical characteristics, female gender, younger age, low mean corpuscular volume (MCV) and increased inflammation biomarkers were associated with iron deficiency, while low ferritin levels, older age, low MCV and male gender were associated with a higher risk of anaemia. The study showed that one in five ambulatory IBD patients presented with anaemia, suggesting the need for screening and treatment optimisation.

P676: E. Mekori-Domachevsky and colleagues, from Sheba Medical Center, Ramat Gan, Israel, studied the prevalence of depression and anxiety in 31,340 IBD patients included between 1997 and 2019 in epi-IIRN, the national cohort of IBD patients in Israel. Compared to 91,535 controls, IBD patients showed a ~1.4 times higher risk of depression/anxiety comorbidity at all time points following IBD diagnosis, with female gender being the most prominent risk factor (HR ~1.5, p<0.001). The study emphasised the need to monitor for symptoms of depression and anxiety among IBD patients and for prompt intervention and follow-up by a mental health care provider when such symptoms are detected.

P652: Similarly, D.N. Umar and colleagues, from Sandwell and West Birmingham NHS Trust, West Bromwich, United Kingdom, used The Health Improvement Network (THIN) database to investigate forms of mental illness in IBD patients between 1995 and 2021. Compared to matched controls, IBD patients had a statistically significantly increased incidence and prevalence of anxiety, insomnia, depression and deliberate self-harm at 10 years and 2 years prior to IBD diagnosis. The study clearly showed an additional burden of mental illness in patients who are later diagnosed with IBD. Patients who develop mental illness are at particularly high risk of deliberate self-harm.

DOP07: On the same track, the link between mental complaints and chronic pain in IBD patients was studied by A. Rezazadeh Ardabili Maastricht University Medical Center, Maastricht, the Netherlands, who analysed data collected by MyIBDCoach between 2020 and 2021 from 559 patients representing a real-world population (including 429 in biochemical remission). They found that 198 (46.2%) of those in biochemical remission had chronic abdominal pain. These patients were characterised by female sex, higher BMI, shorter disease duration and significantly higher levels of stress, fatigue, depressive and anxiety symptoms, and occurrence of life events. The authors linked this observation to the gut–brain interaction represented by higher levels of depressive and anxiety symptoms, but the relation to abdominal pain is potentially modulated through increased levels of perceived stress.

4. Management of IBD in extreme conditions!

DOP04: I. Bastón Rey and colleagues, from Ospital Clínico Universitario de Santiago De Compostela, Santiago De Compostela, Spain, studied 177 patients from 31 centres in a retrospective nationwide study. The study showed that one-third of 106 patients with pre-existing IBD had disease progression after solid organ transplant and needed medical therapy escalation, surgery or hospitalisation. Active IBD at the time of transplantation and the presence of extraintestinal manifestations were risk factors for disease progression. Of the 71 de novo IBD patients, about half showed disease progression during follow-up.

In concluding this report, I would like to reiterate the point raised by T. Chhibba and colleagues (P643), namely that patients who have complications of the disease, extensive surgery or altered anatomy are not reflected in current RCTs. The question remains to what extent the findings from RCTs are generalisable to the general IBD population.