Sex hormones and the incidence of severe retinopathy in male subjects with type I diabetes.

BACKGROUND: Diabetic retinopathy rarely occurs before puberty, suggesting that changes in sex hormones may influence the development of this condition.
METHODS: The authors measured total testosterone, free testosterone, sex hormone-binding globulin, estradiol, and dehydroepiandrosterone-sulfate levels in 44 men with type I diabetes participating in the 1984 to 1986 re-examination phase of the Wisconsin Epidemiologic Study of Diabetic Retinopathy, a population-based study of diabetic complications. The mean age was 32.7 years, and the mean duration of diabetes was 15.4 years. Subjects who progressed to proliferative or preproliferative retinopathy 6 years later (cases, n = 22) were compared with subjects who had little or no progression (controls, n = 22). Both groups were matched on initial level of retinopathy. Seven stereoscopic retinal photographs of each eye were obtained at both examinations, and the photographs were read by the University of Wisconsin Reading Center.
RESULTS: Sex hormone-binding globulin concentrations (nmol/l) were significantly lower (reflecting increased androgenicity) in cases than in controls (22.4 +/- 11.4 versus 32.5 +/- 19.8; P = 0.04). No other statistically significant differences in hormone levels were observed.
CONCLUSION: Neither serum testosterone nor other sex hormones were related to the incidence of severe retinopathy. The relationship to low-serum sex hormone-binding globulin suggests that increased androgenicity may be associated with the progression of retinopathy in male subjects with type I diabetes.