Coeliac disease and diabetes mellitus: a study of 24 patients with HLA typing.

The clinical features of 24 patients with coeliac disease and insulin-dependent diabetes mellitus were reviewed. The HLA types of 17 of these patients were compared with those of 44 normal subjects, 49 patients with diabetes only and 58 patients with coeliac disease only. The diagnosis of coeliac disease was made after the diagnosis of diabetes in 14 patients, before diabetes in five and simultaneously in five. In established diabetics, coeliac disease was recognized relatively late (mean age 31 years) but the average duration of symptoms attributable to coeliac disease prior to a jejunal biopsy was five months. Gluten restriction was generally followed by a marked improvement in diabetic control. The frequency of HLA-DR3 in patients with coeliac disease and diabetes mellitus (88 per cent), patients with coeliac disease only (88 per cent), and patients with insulin-dependent diabetes mellitus only (69 per cent), was significantly greater than in normal subjects (44 per cent). The subtype of diabetes related to DR4/B15 does not appear to predispose to coeliac disease. The mechanism of the association between coeliac disease and insulin-dependent diabetes is discussed and the importance of coeliac disease in the differential diagnosis of 'diabetic diarrhoea' is emphasized.