Diabetic microangiopathy in patients with cystic fibrosis.

Individuals with cystic fibrosis have a 1% to 7% incidence of insulin-dependent diabetes mellitus. The occurrence of diabetic microangiopathy in patients with cystic fibrosis has been reported recently. From 1978 to 1987, 19 patients with cystic fibrosis and diabetes mellitus were followed up. Four patients (21%) had evidence of diabetic microangiopathy. In one, peripheral neuropathy developed 5 years after the onset of diabetes mellitus, and the other 3 patients each had complications of retinopathy, nephropathy, and neuropathy which developed 10 years after the onset of diabetes mellitus. All were poorly compliant in their medical care. Significant morbidity was seen in the 3 patients with multisystem involvement--blindness, glaucoma, hypertension, and renal failure. The combination of long-standing diabetes mellitus, poor glycemic control, plus pathophysiologic features associated with cystic fibrosis may have contributed to the development of microangiopathy. The use of steroids in 4 other patients and dextrose infusions (as part of hyperalimentation) in another 4 patients precipitated or exacerbated diabetes. The data indicate that diabetic microangiopathy can occur in the individual with cystic fibrosis. Routine screening for diabetes and its complications in the population with cystic fibrosis, as well as optimal control of hyperglycemia, is warranted.