A recent study (A Unalp-Arida et al. Gastroenterol 2017; 152: 1922-32) examines the relationship of latitude and the prevalence of celiac disease and gluten avoidance.
Using the NHANES 2009-2014 survey with 22,277 participants (6 years and older), the authors identified persons with celiac disease (based on serology) along with those who avoided gluten without a diagnosis of celiac disease.
- 0.7% of participants had celiac disease and 1.1% avoided gluten without celiac disease
- Celiac disease was more common among individuals who lived at latitudes of above 35 degrees and more common with higher socioeconomic status. Figure 2 map provides latitude lines. In the eastern U.S. the Georgia-Tennessee border corresponds to this latitude line and in the western U.S. the southern tip of Nevada lies on this line.
- From 35 degrees to 39 degrees the odds ratio was 3.2, whereas the odds ratio was 5.4 for those above 40 degrees. These odds ratios were independent of race, ethnicity, socioeconomic status and body mass index.
- Similarly, the prevalence of gluten avoidance without celiac disease was twice as common among persons living north of 40 degrees compared with those residing at latitudes <35 degrees.
- The findings on latitude were heavily influenced by the increased rate of celiac and gluten avoidance in the Northeast region (more so than in the West)
In their discussion, the authors note that “a North-South gradient in disease occurrence in genetically similar populations has been shown in studies of autoimmune diseases, including inflammatory bowel disease, multiple sclerosis, and rheumatoid arthritis.” Potential environmental factors could include lack of sunshine/vitamin D deficiency, hygiene, and infections. A study comparing similar populations in Finland and Russia suggested a lower economic status/less hygiene increased the risk of celiac disease despite similar gluten exposure. The authors note that there was NOT an increased risk in Northern Sweden compared to Southern Sweden. In fact, this study of children found a higher rate of celiac disease in Southern Sweden (Arch Dis Child 2016; 101: 1114-18).
My take: This is another intriguing study regarding celiac disease epidemiology which strongly points to environmental factors accounting for marked variation in celiac disease prevalence.
More information on this topic from AGA Blog: Do More People Have Celiac Disease in the North vs the South?
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- Vaccine for Celiac Disease
- Celiac Disease Risk –TEDDY study
- Celiac Disease and Mode of Delivery -Perhaps Not Very Consequential
- Celiac disease and diabetes
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- How Birth Can Affect Your GI Tract | gutsandgrowth
- How to Protect Children From Celiac Disease
- Why are we seeing so many more cases | gutsandgrowth
- Why is Celiac Disease Becoming More Prevalent?