Growth hormone has been considered to be the cause of diabetic retinopathy. However the relationship between growth hormone responses and diabetic retinopathy has not been consistent. Moreover, the correlation (if any) between the severity of retinopathy and growth hormone changes are also not well defined. In the present study 23 diabetics (16 with retinopathy, 7 without retinopathy) and 8 non-diabetic healthy controls were studied. Serum growth hormone was measured in the fasting state and one hour after levodopa administration. The mean growth hormone levels were significantly higher in the diabetics as compared to controls, however there was no correlation between the mean growth hormone levels (either in the fasting state or after levodopa stimulation) and presence or absence of diabetic retinopathy although diabetics with retinopathy had significantly greater mean growth hormone response. The mean growth hormone was found to have no correlation with the fasting blood sugar levels. Diabetics with back ground retinopathy had significantly greater mean growth hormone levels than those with proliferative retinal changes
