Incidence and risk of celiac disease after type 1 diabetes: A population-based cohort study using the health improvement network database

Objective To determine the incidence of and risk factors for development of celiac disease (CD) in individuals with type 1 diabetes. Methods Cohort study using The Health Improvement Network (THIN), a UK primary care database of >13 million people. Individuals with incident type 1 diabetes diagnosed at 1 to 35 years of age between 1995 and 2015 with no previous diagnosis of CD were included. Cox regression was used to identify risk factors for CD, including age at diabetes diagnosis and sex, while adjusting for year of diagnosis to control for potential rising incidence in CD over time. Results Subjects (n = 9180; 43% female) had a median observation time of 5.1 years (interquartile range 2.0-10.1). CD was diagnosed in 196 (2%) during follow up. Median time to diagnosis was 2.1 years, but 25% were diagnosed more than 5 years after diabetes diagnosis. Incidence (per 10 000 person-years) was greater in females (43.0 [95% confidence interval [CI] 35.2-52.0]) vs males (26.8 [95% CI 21.5-32.9]). In multivariable Cox regression stratified by childhood- vs young adult-onset diabetes, younger age at diabetes diagnosis within childhood (hazard ratio [HR] 0.91 [95% CI 0.88-0.94]) and female sex among the adult-onset diabetes group (HR 3.19 [95% CI 1.39-7.34]) were associated with greater risk of CD. Conclusions As expected, incidence of CD was higher in individuals with childhood-onset diabetes vs those with adult-onset diabetes. However, individuals with diabetes are at risk of developing CD throughout childhood and adulthood, and prolonged screening after diagnosis may be warranted. Prospective studies are needed in order to guide risk-stratified approaches to screening.