Nephrogenic diabetes insipidus associated with hemochromatosis.

Although hemochromatosis is one of the most common genetic disorders in humans, the clinical information on iron-induced renal impairment is limited. We describe the clinical features of nephrogenic diabetes insipidus (NDI) observed in a case of hemochromatosis. A 57-year-old diabetic man was admitted to the hospital with a 6-month history of persistent polyuria, which had been sustained after glycemic optimization with insulin therapy and resulted in hepatic coma. Despite sufficient basal excretion of arginine vasopressin, impaired urinary concentrating capacity was observed, which could not be corrected by supraphysiologic doses of exogenous arginine vasopressin. Histochemical investigations showed widely distributed iron deposition in hepatocytes and moderately increased iron deposits in the tubular epithelium of distal urinary tubules and collecting ducts, suggesting that iron deposition resulting from hemochromatosis leads to NDI. This may be the first case report of NDI associated with hemochromatosis in humans. More attention should be paid to latent NDI as another complication of hemochromatosis.