Trends in the prevalence rates and predictive factors of coeliac disease: A long-term nationwide follow-up study

Background: The prevalence of coeliac disease doubled in Finland from 1980 to 2000. Aims: To investigate whether this increase is continuing and if there are specific patient-related factors predicting the development of coeliac disease at a population level. Methods: We elicited comprehensive health data in the nationwide Health 2000 and Health 2011 surveys. Serum samples were taken for the measurement of tissue transglutaminase antibodies (TGA); subjects who were seropositive were tested for endomysial antibodies (EmA). Coeliac disease was defined either as a reported diagnosis or as positive TGA and EmA. The surveys comprised, respectively, 6379 and 4056 individuals, forming representative samples for 2,946,057 and 2,079,438 Finnish adults. Altogether 3254 individuals participating in both surveys comprised a prospective follow-up cohort. Results: Prevalence of coeliac disease was 2.12% in 2000 and 2.40% in 2011 (p = 0.156). In the prospective cohort, 16 out of the 3254 (0.49%) subjects developed coeliac disease during follow-up from 2000 to 2011, with an annual incidence rate of 45 per 100,000 persons. Positive TGA without EmA (OR: 133, 95% CI: 30.3–584), TGA values in the upper normal range (51.1, 16.0–163), and after adjusting for TGA, previous autoimmune co-morbidity (8.39, 4.98–35.9) in 2000 increased the likelihood of subsequent coeliac disease. Conclusions: The nationwide prevalence of coeliac disease kept on rising from 2.12% in 2000 to 2.40% in 2011 in Finland. Positive TGA without EmA, TGA titres in the upper normal range and a pre-existing autoimmune disease predisposed to coeliac disease during the 10-year follow-up.