Autoimmune polyglandular syndrome type 3 complicated by mineralocorticoid-responsive hyponatremia of the elderly.

We experienced the first case with autoimmune polyglandular syndrome type 3 (anti-thyroid peroxidase antibody-positive hypothyroidism and anti-glutamic acid decarboxylase antibody-positive diabetes) complicated by mineralocorticoid-responsive hyponatremia of the elderly. This case is also a rare slowly progressive insulin-dependent diabetes mellitus (SPIDDM) case, for which the patient has been treated for many years with sulfonylurea or glinide. Our observation also demonstrated that glucose metabolism in autoimmune diabetes such as SPIDDM is influenced by appetite, thyroid function and glucocorticoid effect.