Insufficient awareness of celiac disease in China: population-based screening is needed

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Insufficient awareness of celiac disease in China: population-based screening is needed

For over 4,000 years, wheat has been a cornerstone of Chinese cuisine—from the hand-pulled noodles of Xi’an to the chewy “mianjin” (gluten) snacks sold on street corners. But for some, this beloved grain hides a dangerous secret: celiac disease (CD), an autoimmune condition triggered by gluten that’s vastly underrecognized in China.

Chu-Yan Chen and Jing-Nan Li, gastroenterologists at Peking Union Medical College Hospital (a leading institution under the Chinese Academy of Medical Sciences), argue that low awareness among clinicians and limited access to proper testing mean most Chinese CD cases are “the tip of the iceberg”—hidden from diagnosis and putting lives at risk.

What Is Celiac Disease?

CD isn’t just a gut problem—it’s a systemic autoimmune disorder. It strikes people with specific genetic markers (HLA-DQ2 or HLA-DQ8) when they eat gluten, a protein in wheat, barley, and rye. Classic symptoms include chronic diarrhea, bloating, or weight loss, but it can also cause iron deficiency (from poor nutrient absorption), osteoporosis (low calcium), skin rashes (like dermatitis herpetiformis), or even recurrent miscarriages. For decades, CD was thought to mainly affect people of European descent—but global research shows it’s a worldwide health issue.

Global Prevalence vs. China’s “Hidden” Cases

A 2018 systematic review found CD affects about 1 in 143 people globally (0.7% prevalence). But in China, CD is so rarely diagnosed that most cases are only reported in small case series or single patient stories. Why? The biggest barriers are low awareness among doctors and a lack of standardized testing.

CD Is Emerging in China—But Few Are Noticing

Recent studies suggest CD is more common in China than previously thought:

  • A 2017 study of 19,778 Chinese adolescents and young adults found 2.19% had signs of CD autoimmunity (meaning their immune systems were reacting to gluten). Rates were even higher in wheat-heavy northern provinces.
  • Another study found 1.77% of adults with diarrhea-predominant irritable bowel syndrome (IBS) had positive CD serology—and 4 out of 7 of those cases were confirmed by biopsy.
  • Strikingly, 22% of patients with type 1 diabetes or autoimmune thyroid disease showed CD autoimmunity, according to a 2016 study.

Genetics play a role too. While 25–30% of Caucasians carry the HLA-DQ2 gene linked to CD, Chinese people have lower but still significant rates: 3.4% have HLA-DQ2.5 and 2.1% have HLA-DQ8, per a 2013 meta-analysis. That’s enough to support more CD cases than we’re seeing—so low awareness, not genetics, is the bigger issue.

And it’s not because Chinese people eat less wheat. Wheat has been a major food here for millennia, especially in the north. Plus, as diets become more Westernized—with more bread, pizza, and processed foods—gluten exposure is rising. This means CD cases are likely to increase in the future.

Why Missing CD Diagnoses Is Dangerous

Undiagnosed CD is life-threatening. It can lead to severe malabsorption (meaning the body can’t take in nutrients), causing fatigue, weak bones, or anemia. It also raises the risk of lymphoma (a type of cancer) and even death: a 2009 study found undiagnosed CD patients have a 4 times higher risk of dying than those without CD.

That’s why Chen and Li stress the need for doctors to be more alert. Patients with symptoms of malabsorption (like chronic diarrhea or bloating) should be tested for CD. So should people with “atypical” signs: unexplained iron deficiency anemia, elevated liver enzymes, or type 1 diabetes. Treatment—a strict gluten-free diet—often resolves these issues.

The IBS Connection: A Major Source of Misdiagnosis

One of the biggest challenges is the overlap between CD and IBS. Up to 50% of CD patients meet the Rome criteria for IBS (the standard for diagnosing functional gut disorders). This means some CD patients are mislabeled as having IBS—delaying treatment for years.

A 2017 meta-analysis found 3.3% of IBS patients have biopsy-proven CD—4.5 times higher than the general population. A study in Shandong Province confirmed this in China: 2.85% of IBS patients were diagnosed with CD. For Chen and Li, this means doctors should test for CD in any patient with IBS-like symptoms—especially if they’re from wheat-heavy regions.

How to Diagnose CD Correctly

Diagnosing CD requires three key steps:

  1. Medical History: Symptoms (like chronic diarrhea) or high-risk status (e.g., type 1 diabetes).
  2. Serology: Blood tests to detect immune reactions to gluten. The most accurate test is IgA anti-tissue transglutaminase (tTG-IgA), which has 95% sensitivity and specificity. Critical note: Blood tests only work if you’re still eating gluten—going gluten-free before testing can give false negatives.
  3. Duodenal Biopsy: A sample of the small intestine showing villous atrophy (damage to the tiny, nutrient-absorbing projections lining the gut). CD causes patchy damage, so doctors need to take 1–2 samples from the duodenal bulb and 4+ from the distal duodenum.

Some Chinese studies use anti-gliadin antibodies (AGAs), but these are only reliable for children under 18 months or in high-prevalence groups. Tests like tTG-IgA or endomysium antibodies are far more specific—and need to be more widely available in China.

What Comes Next: Screening and Awareness

The true burden of CD in China is unknown—but the signs point to widespread underdiagnosis. To fix this, Chen and Li call for:

  • Population-based screening: Large-scale studies to find hidden CD cases.
  • Clinician training: Teaching doctors to recognize CD symptoms and test high-risk patients.
  • Standardized testing: Making accurate serology (like tTG-IgA) and biopsy procedures more accessible.
  • Gluten-free food access: If screening reveals many undiagnosed cases, China will need more gluten-free options—something a 2018 survey found is a major challenge for current CD patients.

If screening shows CD is rare in China, it will raise fascinating questions: What genetic or environmental factors protect Chinese people from gluten reactivity? But regardless of the outcome, the first step is to raise awareness.

As Chen and Li write: “Through active investigation, the hidden part of the ‘celiac iceberg’ in China will gradually emerge.” For the millions of Chinese people potentially living with undiagnosed CD, that emergence can’t come soon enough.

  1. Singh P, Arora A, Strand TA, et al. Global prevalence of celiac disease: systematic review and meta-analysis. Clin Gastroenterol Hepatol 2018;16:823–836.e2. doi.org/10.1016/j.cgh.2017.06.037
  2. Yuan J, Gao J, Li X, et al. The tip of the “celiac iceberg” in China: a systematic review and meta-analysis. PLoS One 2013;8:e81151. doi.org/10.1371/journal.pone.0081151
  3. Poddighe D, Rakhimzhanova M, Marchenko Y, et al. Pediatric celiac disease in central and east Asia: current knowledge and prevalence. Medicina 2019;55:11. doi.org/10.3390/medicina55010011
  4. Yuan J, Zhou C, Gao J, et al. Prevalence of celiac disease autoimmunity among adolescents and young adults in China. Clin Gastroenterol Hepatol 2017;15:1572–1579. doi.org/10.1016/j.cgh.2017.04.025
  5. Wang H, Zhou G, Luo L, et al. Serological screening for celiac disease in adult Chinese patients with diarrhea predominant irritable bowel syndrome. Medicine 2015;94:e1779. doi.org/10.1097/md.0000000000001779
  6. Zhao Z, Zou J, Zhao L, et al. Celiac disease autoimmunity in patients with autoimmune diabetes and thyroid disease among Chinese population. PLoS One 2016;11:e0157510. doi.org/10.1371/journal.pone.0157510
  7. Lazar-Molnar E, Snyder M. The role of human leukocyte antigen in celiac disease diagnostics. Clin Lab Med 2018;38:655–668. doi.org/10.1016/j.cll.2018.07.007
  8. Rubio-Tapia A, Kyle RA, Kaplan EL, et al. Increased prevalence and mortality in undiagnosed celiac disease. Gastroenterology 2009;137:88–93. doi.org/10.1053/j.gastro.2009.03.059
  9. Rubio-Tapia A, Hill ID, Kelly CP, et al. ACG clinical guidelines: diagnosis and management of celiac disease. Am J Gastroenterol 2013;108:656–676. doi.org/10.1038/ajg.2013.79
  10. Bibbins-Domingo K, Grossman DC, Curry SJ, et al. Screening for celiac disease: US Preventive Services Task Force Recommendation Statement. JAMA 2017;317:1252–1257. doi.org/10.1001/jama.2017.1462
  11. O’Leary C, Wieneke P, Buckley S, et al. Celiac disease and irritable bowel-type symptoms. Am J Gastroenterol 2002;97:1463–1467. doi.org/10.1111/j.1572-0241.2002.05690.x
  12. Irvine AJ, Chey WD, Ford AC. Screening for celiac disease in irritable bowel syndrome: an updated systematic review and meta-analysis. Am J Gastroenterol 2017;112:65–76. doi.org/10.1038/ajg.2016.466
  13. Kou GJ, Guo J, Zuo XL, et al. Prevalence of celiac disease in adult Chinese patients with diarrhea-predominant irritable bowel syndrome: a prospective, controlled, cohort study. J Dig Dis 2018;19:136–143. doi.org/10.1111/1751-2980.12587
  14. Ludvigsson JF, Bai JC, Biagi F, et al. Diagnosis and management of adult coeliac disease: guidelines from the British Society of Gastroenterology. Gut 2014;63:1210–1228. doi.org/10.1136/gutjnl-2013-306578
  15. Reilly NR, Husby S, Sanders DS, et al. Coeliac disease: to biopsy or not? Nat Rev Gastroenterol Hepatol 2018;15:60–66. doi.org/10.1038/nrgastro.2017.121
  16. Lagerqvist C, Dahlbom I, Hansson T, et al. Antigliadin immunoglobulin A best in finding celiac disease in children younger than 18 months of age. J Pediatr Gastroenterol Nutr 2008;47:428–435. doi.org/10.1097/MPG.0b013e31817d80f4
  17. Villanacci V, Ceppa P, Tavani E, et al. Coeliac disease: the histology report. Dig Liver Dis 2011;43(Suppl 4):S385–S395. doi.org/10.1016/s1590-8658(11)60594-x
  18. Lu Z, Zhang H, Luoto S, et al. Gluten-free living in China: the characteristics, food choices and difficulties in following a gluten-free diet – an online survey. Appetite 2018;127:242–248. doi.org/10.1016/j.appet.2018.05.007

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