Are we beyond the peak of celiac disease incidence in Olmsted County, Minnesota, USA?

Background and Objectives: The incidence of celiac disease (CD) has increased over the past few decades. Recent reports suggest the incidence has peaked and plateaued in many countries. We aimed to demonstrate the CD incidence trend since 2000 in a well-defined US population. Methods: Using the Rochester Epidemiology Project (REP), we reviewed electronic health records for patients of Mayo Clinic and Olmsted Medical Center between 2000 and 2021. We identified patients diagnosed with CD during the study period and resided in Olmsted County, Minnesota. Incidence rates (per 100,000 person-years) were calculated by age, sex, and calendar year and adjusted to the 2020 US population. Results: Among 622 patients diagnosed with CD during the study period, 179 (29%) were children and 395 (64%) were female. Median age at diagnosis among pediatric and adult patients was 9.2 years and 42.2 years, respectively. Overall CD incidence rate increased and peaked at 24.9 in 2015 through 2017. Incidence plateaued in the later part but remained higher at the end of the study period. The increased incidence rate was influenced primarily by children younger than 11 years, whose incidence almost tripled during the study period. A clear decreasing trend was noted only among adults older than 64 years. Conclusion: Although the overall CD incidence rate is plateauing in Olmsted County, it continued to increase among children. This could indicate a shift to increase awareness and earlier diagnosis.