Severe non-diabetic ketoacidosis due to starvation and Graves' disease.

Starvation-induced non-diabetic ketoacidosis (NDKA) is a typically mild condition. Here, we report life-threatening NDKA induced by a brief period of starvation in a patient with undiagnosed hyperthyroidism. A Japanese woman in her mid-30s, with intellectual disabilities and selective mutism, presented with a 3 day history of vomiting and anorexia. She developed severe high-anion-gap metabolic acidosis, marked by elevated serum ketone bodies and normal blood glucose levels. Furthermore, mild-to-moderate hyperthyroidism was detected, which was later diagnosed as Graves' disease. The patient required intensive care, including a single session of haemodialysis, intravenous glucose-containing fluids, antithyroid medication and continuous intravenous beta-blocker infusion. These interventions led to acidosis resolution and normalisation of thyroid function. This case highlights that coexisting hyperthyroidism, even if mild to moderate, could dramatically exacerbate starvation-induced NDKA. Clinicians should consider hyperthyroidism in patients presenting with severe ketoacidosis.