Retinopathy and Plasma Growth Hormone Levels in Idiopathic Hemochromatosis with Diabetes

In patients with idiopathic hemochromatosis, retinopathy was investigated by ophthalmoscopy and fluorescein angiography and was present in eight out of 23; this prevalence is similar to that reported in patients with diabetes aged between 30 and 60 years at onset of diabetes and with the same duration of the disease; in these eight patients retinopathy was of mild degree, with no impairment of visual acuity, fewer than 10 microaneurysms in each fundus, and no other retinal abnormalities. Plasma growth hormone response to arginine stimulation was studied in 10 patients with hemochromatosis and diabetes and was significantly lowered compared with uncomplicated diabetes and with nondiabetic subjects. Plasma growth hormone response to insulin-induced hypoglycemia was studied in six patients with hemochromatosis and diabetes and was significantly lowered as compared with nondiabetics. It is suggested that the blunted growth hormone secretion in idiopathic hemochromatosis acts as a protective factor and could explain the mild degree of the retinopathy; this would support the hypothesis on a possible role of growth hormone in the development of diabetic microangiopathy.