Singh P, et al. “Global Prevalence of Celiac Disease: Systematic Review and Meta-analysis” Clinical Gastroenterology and Hepatology 2017. https://www.ncbi.nlm.nih.gov/pubmed/29551598
A large scale review and analysis was conducted of studies on celiac disease (CD) prevalence. Previous prevalence data had come primarily from European studies, and showed that CD was estimated to affect approximately 1 % of the European population. Over the last few decades, prevalence data has been reported from other parts of the world as well. The present study utilized this expanded data base, encompassing the following regions: Asia, Europe, Africa, South America, North America, and Australia.
3843 published articles on CD prevalence were screened for inclusion in this analysis. Studies from the time period 1991 – 2016 were included. Earlier studies were not included because 1990 was considered the cut off year for establishment of well-defined diagnostic criteria for CD.
Two categories of prevalence were analyzed: prevalence based on positive antibody results (sero-prevalence), and prevalence based on confirmation by biopsy. Sero-prevalence was based on testing for anti–tissue transglutaminase and/or anti-endomysial antibodies.
The final number of studies included in the analysis was 96. Reasons for exclusion included studies in which only high risk subjects were screened (e.g. those with type 1 diabetes), studies which documented CD prevalence based on self-reporting, or studies in which individuals were screened using anti-gliadin antibody testing (AGA), which is no longer recommended as a sole screening test for CD.
All 96 studies (which included 275,818 individuals) were used to calculate sero-prevalence. 57 studies (which included 138,792 individuals) were included in analyzing biopsy-confirmed celiac disease.
[The term “pooled” is used in relation to the fact that data from multiple studies was combined (or “pooled”) and analyzed to yield the results.]
The pooled global prevalence of celiac disease was found to be 1.4% based on positive serology, and .7% based on positive biopsy. It was also found that the prevalence of biopsy-confirmed celiac disease increased over time from 0.6 % between 1991 and 2000, to 0.8% between 2001 and 2016.
Gender and Age Differences
Only 33 studies reported separate pooled prevalence of biopsy-confirmed CD for males and females; among these it was found that prevalence was 1.5 times higher in females than males. Comparing adults and children, biopsy-confirmed prevalence was found to be significantly greater in children than adults (0.5% in adults and 0.9% in children).
Prevalence of biopsy-confirmed celiac disease varied by region as follows: 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania. More specific data on biopsy-proven CD was as follows: On the high end, Argentina, Egypt, Hungary, Finland, India, New Zealand, and Sweden had a pooled prevalence of 0.9% – 2.4%. On the lower end of the scale in countries where data on biopsy confirmed CD was available, the following countries had a pooled prevalence of between 0.2% and 0.4%: Brazil, Germany, Republic of San Marino, Russia, and Tunisia.
The sero-prevalence of CD was observed to be highest in Asia (1.8%) and lowest in Africa (1.1%). (The studies included in this analysis from Africa were primarily from the northern part of the continent.) On the high end, the following group of countries had a pooled sero-prevalence of between 2.1% and 8.5%: Algeria, Czech Republic, India, Israel, Mexico, Malaysia, Saudi Arabia, Sweden, Portugal, and Turkey. On the lower end were the following group, with a pooled sero-prevalence of between 0.2% and 0.8%: Estonia, Germany, Iceland, Libya, Poland, Republic of San Marino, Spain, and Switzerland.
According to the authors, factors responsible for geographic differences found are likely genetic (including HLA and non-HLA genes), and environmental – including patterns of wheat consumption, age at wheat introduction, infant feeding practices, gastrointestinal infections, antibiotic and proton-pump inhibitor use, and C-section rates.
The authors note that of the world’s 10 most populous countries, population-based prevalence data on CD are available from only 4: India, U.S., Brazil and Russia. They further note that population-based prevalence data from the other 6 most populous countries (China, Indonesia, Pakistan, Nigeria, Bangladesh, and Japan) are lacking, although CD has been reported in each of these countries except Nigeria. The authors note that prevalence data from Russia, a country with a population of 143 million, is sparse, including only 3728 individuals, and that there is a possibility of a large celiac disease burden in Russia, something which needs to be explored.
In addition, the authors conclude that there is a need for well-designed population-based studies from many other countries.