Abstract
A 19-year-old obese male had been diagnosed with pan-hypopituitarism, complete diabetes insipidus (DI), and hypothalamic hyperthermia after a craniotomy performed for craniopharyngioma four years previously. He also had adipsia after the operation. Since 1990, this patient had been re-admitted 3 times with a diagnosis of hyperglycemic hyperosmolar nonketotic coma (HHNC). Prior to each episode, he had had a common cold and had consumed a large quantity of sugar-containing soft drinks because of excessive dryness of the oral mucous membranes, but without thirst sensation. A 75-g oral glucose tolerance test showed impaired glucose tolerance with fasting hyperinsulinemia after discharge. Although the patient's fasting plasma glucose and HbA1c have always been within normal range, a state of hyperosmolarity and hypernatremia due to DI and adipsia has persistently been observed during the 5-year follow-up period after recovery from HHNC. We concluded that the pathophysiological mechanisms of HHNC underlying this case were as follows: 1) a persistent hyperosmolar state due to DI, adipsia, and hypothalamic hyperthermia; 2) glucose intolerance and insulin resistance; and 3) exacerbation of these factors due to viral infection and excessive consumption of sugar-containing soft drinks.
