Objectives: To study, by sequential screening for gliadin antibodies (GA) and endomysial antibodies (EMA), the prevalence and clinical characteristics of coeliac disease (CD) in adult IDDM patients.
Subjects and measurements: A series comprising 1664 diabetes patients [848 with IDDM, 745 with non-insulin-dependent diabetes (NIDDM) and 71 with secondary diabetes] were screened for GA. IgA- or IgG-GA positive sera were analysed for EMA.
Results: IgA-GA were more frequent in all the diabetes subgroups (13.7% in IDDM,12.3% in NIDDM and 23.9% in secondary diabetes, P < 0.001 in all three cases) than among healthy blood donors (4.7%). Two patients with NIDDM had CD. Of the IDDM group (n = 848), 8 had previously diagnosed CD and 14 more (of whom 7 could be biopsied) were EMA positive. All had villous atrophy. The minimum prevalence of CD (including probable cases) in IDDM was 2.6% (22/848). Patients with previously known CD had more symptoms (P < 0.001), more deficiency states (P < 0.001) and more autoimmune diseases (P < 0.04) than those identified by screening. IDDM patients with a diabetes duration of 31-40 years were characterised by a higher prevalence of CD than patients with a duration of less than 30 years (6.7% vs. 1.7%; P < 0.02).
Conclusions: Serial analysis of GA and EMA confirmed a high prevalence of CD in adult IDDM (2.6%). False-positive IgA-GA test results are frequent in patients with diabetes, irrespective of type. EMA analysis is the preferable screening tool for CD in diabetes.