To see if glucocorticoid deficiency might explain increased insulin sensitivity causing severe brittle diabetes in two type 1 diabetic patients.
We describe two patients who developed brittle diabetes characterized by recurrent severe hypoglycemia on small daily insulin doses with severe hyperglycemia on further insulin dose reduction. In both patients, insulin requirements had fallen markedly.
Both patients were found to have glucocorticoid deficiency. In one patient, this was a result of hypopituitarism, in which hypoglycemia was aggravated by growth hormone deficiency. In the other patient, glucocorticoid deficiency was the result of primary adrenal failure. Resolution of brittle diabetes and restoration of normal insulin doses followed steroid replacement therapy in both patients.
These patients emphasize the importance of seeking an organic cause for recurrent severe hypoglycemia. Increasing insulin sensitivity in type I diabetic patients should alert clinicians to the possibility of glucocorticoid deficiency.
