Prevalence rates of type 1 diabetes (T1D) and celiac disease (CD) vary from 1.6% to 16.4% worldwide. Screening guidelines are variable and not evidence based. Our aim was to conduct a systematic review of CD in T1D.
Medline, Embase, and the Cochrane Library were searched. Studies were limited to those in English and in humans. We selected longitudinal cohort studies screening for CD in T1D with at least 5 years of follow-up. Screening rates, characteristics, and prevalence of biopsy-proven CD in people with T1D were extracted.
We identified 457 nonduplicate citations; 48 were selected for full-text review. Nine longitudinal cohort studies in 11 157 children and adolescents with 587 cases of biopsy-proven CD met the inclusion criteria. Median follow-up was 10 years (range: 5–18 years). The weighted pooled prevalence of CD was 5.1% (95% confidence interval: 3.1–7.4%). After excluding 41 cases with CD onset before T1D, CD was diagnosed in 218 of 546 (40%) subjects within 1 year, in 55% within 2 years, and in 79% within 5 years of diabetes duration. Two studies (478 cases) reported higher rates of CD in children aged <5 years at T1D diagnosis. The duration of follow-up varied across the included studies. CD screening frequency progressively decreased with increased T1D duration.
Because most cases of CD are diagnosed within 5 years of T1D diagnosis, screening should be considered at T1D diagnosis and within 2 and 5 years thereafter. CD screening should be considered at other times in patients with symptoms suggestive of CD. More research is required to determine the screening frequency beyond 5 years of diabetes duration.