CUHK Announces World’s First Systematic Review of the Global Incidence and Prevalence of Inflammatory Bowel Diseases in the 21st Century Reveals Surge in Hong Kong in past 30 years

Researchers from The Chinese University of Hong Kong (CUHK) have conducted the world’s first systematic review of the global incidence and prevalence of Inflammatory Bowel Diseases (IBD) in the 21^st century and found a continuous surge in the non-western world, with the incidence in Hong Kong having risen about 30 times in the past 30 years, much more seriously than in other Asia regions, such as Japan, Taiwan and Singapore. CUHK’s researchers regard this increase as alarming and think that IBD has emerged as a public health challenge worldwide. However, the continual surge also provides unique opportunities to identify the cause of IBD. Results of the systematic review have just been published in the leading medical journal The Lancet and presented yesterday in the World Congress of Gastroenterology in Orlando, USA.

Crohn’s disease (CD) and ulcerative colitis (UC) are the two main subtypes of IBD which could lead to inflammation and ulceration of the gut. The onset of the disease frequently occurs in early life with the peak onset between 20 and 40 years of age, and with lifelong symptoms such as rectal bleeding, mucus in stool, abdominal pain, diarrhoea, weight loss, fever and extra-intestinal inflammation of other organs including the eyes, skin and joints. Treatment for IBD usually involves drug therapy, or in some severe cases, surgery.

IBD was traditionally regarded as a disease of Westernized nations. Over 1.5 million and 2 million people suffer from the disease in North America and Europe respectively and it imposes a heavy burden on the local healthcare systems. However, newer epidemiologic studies indicate that the incidence and prevalence are rising in Asia, South America, Eastern Europe and Africa, highlighting that IBD has emerged as a public health challenge worldwide.

In order to provide insights into the epidemiology of IBD in the 21^st century from a global perspective, researchers from CUHK, including Prof. Joseph SUNG, Vice-Chancellor and President of CUHK; Prof. Francis CHAN, Dean of the Faculty of Medicine; and Prof. Siew Chien NG, Professor of the Department of Medicine and Therapeutics, together with gastroenterologists and epidemiologists from the University of Calgary in Canada conducted a systematic review which is the most updated and comprehensive worldwide. The research team evaluated more than 11,000 studies on IBD, published from 1990 to 2016. Among them, 147 studies were identified for full-text review.

Results showed that there is a paradigm shift in the epidemiology of IBD in the 21^st century. Since 1990, the incidence of IBD has stabilized in the Western world while other regions are showing a rising incidence as they have undergone Westernization, in terms of living style. In Hong Kong, there were 26 new IBD cases in a million people, which are higher than the figures in some other parts of Asia:

Regarding the paradigm shift of IBD incidence observed in the study, Prof. Siew Chien NG, Professor of the Department of Medicine and Therapeutics, Faculty of Medicine at CUHK, stated, ‘The increase in incidence of IBD in regions other than the Western world is alarming. Taking Hong Kong as an example, the figure has increased about 30 times in the past 3 decades. Since the actual causes of IBD remain unknown and there is no cure at present, we believe the golden time to identify the cause or to prevent the disease is in the coming 10 years, before the incidence has peaked.’

Dr. Gilaad KAPLAN, Associate Professor, Cumming School of Medicine at the University of Calgary, added, ‘The high prevalence of IBD in the Western world will challenge clinicians to provide high quality and cost-efficient care to patients with IBD. More striking is the observation that as newly industrialized countries have transitioned towards a Westernized society, IBD emerges and its incidence rises rapidly. Consequently, we will need to prepare our clinical infrastructure and personnel to manage this complex and costly disease.’

Prof. NG and her collaborators are also pursuing several researches to find out the risk factors of IBD. Apart from this very comprehensive and updated systematic review conducted with the University of Calgary, CUHK has just announced that Prof. NG’s team is also collaborating with research centres in Australia and mainland China on a research project entitled ‘The ENIGMA Studies – Eastern Inflammatory Bowel Disease (IBD) Gut Microbiota’ (ENIGMA). This project aims to study the association between IBD, especially Crohn’s disease, and the patients’ gut microbiota and dietary habits.

The team is also studying mothers and infants with IBD in order to identify bacterial transmission pattern that may potentially lead to preventive measures for the disease. Members of the public can learn more about this project via https://www.cuhkibd.org/ or email to digestivehealth@cuhk.edu.hk.