Simultaneous presentation of type 1 diabetes and Graves' disease

The association between type 1 diabetes mellitus and autoimmune thyroid disease is well documented in the literature. Both can coexist although one endocrinopathy usually precedes the other. The simultaneous new onset of both diseases is rarely seen. Hyperthyroidism can precipitate and complicate the management of diabetic ketoacidosis by masking its classical clinical features. Persistent tachycardia after correction of acidosis and dehydration, may be the only suggestion of another coexisting illness such as thyrotoxicosis. We describe the case of a previously healthy woman who developed new onset type 1 diabetes mellitus and Graves' disease, and presented with diabetic ketoacidosis.