Prevalence of pernicious anaemia in patients with Type 1 diabetes mellitusand autoimmune thyroid disease

Aims To determine the prevalence of pernicious anaemia in patients with Typ e 1 diabetes mellitus and autoimmune thyroid disease. Methods A randomly selected asymptomatic group of 63 patients with Type 1 d iabetes who also had autoimmune thyroid disease was studied. Blood samples were taken and assayed for serum B12. Those subjects with serum B12 concent rations below the reference range had a further blood sample taken for dete rmination of intrinsic factor antibody. Results One patient had been diagnosed previously to have pernicious anaemi a. Three patients had low serum B12 concentration and positive intrinsic fa ctor antibody, confirming the diagnosis of pernicious anaemia. The prevalen ce of pernicious anaemia in this population with Type 1 diabetes and concom itant autoimmune thyroid disease was 6.3%. In female patients the prevalenc e of pernicious anaemia was 8.5%. Conclusions Patients who have both Type 1 diabetes mellitus and autoimmune thyroid disease are at risk of developing pernicious anaemia.