Risk factors associated with severe proliferative retinopathy in insulin-dependent diabetes mellitus.

The natural history of disease and suspected risk factors for bad prognosis were investigated in 40 subjects with insulin-dependent diabetes mellitus who had severe retinopathy and in 22 patients with a similar duration of diabetes without evidence of complications. The retinopathy group showed a marked excess of men (ratio 2:1). Examination of the data in the literature also showed a striking excess of men, 61% (P less than 0.001) in patients with insulin-dependent diabetes and severe microvascular disease. In addition, proliferative retinopathy was found to have significant associations with current poor diabetic control, hypertension, and previous treatment with once-daily insulin regimens, particularly with protamine zinc insulin.