Vasoactive mediators and retinopathy during type 1 diabetic pregnancy

PURPOSE: To evaluate the role of various vasoactive hormones in the evolution of diabetic retinopathy during pregnancy and postpartum. METHODS: Retinopathy was graded from fundus photographs of 45 pregnant women with type 1 diabetes and seven pregnant women without diabetes in a prospective study. Markers of renin-angiotensin-system (RAS), plasma renin activity (PRA), angiotensin II (AngII), aldosterone, natriuretic peptides (ANP, BNP, CNP) and adreonomedullin (AM) were measured during the first and third trimesters and at 3 months postpartum. The women with diabetes were grouped by progression of retinopathy during pregnancy and postpartum. RESULTS: Levels of PRA (p = 0.001) and ANP (p = 0.03) were significantly lower in diabetes than in non-diabetes subjects throughout pregnancy and postpartum. No significant differences appeared in levels of AngII, aldosterone, AM, BNP or CNP between the two groups. In multivariate logistic regression analyses with retinopathy progression by the third trimester as the dependent variable, only duration of diabetes qualified in the model (p = 0.027, R = 0.227, Exp(B) = 1.28). CONCLUSIONS: Diabetic pregnancy is associated with lower levels of PRA and ANP compared to non-diabetic pregnancy. Lowered RAS activity may contribute to the hyperdynamic blood flow and progression of DR during diabetic pregnancy. Within the power of this study no clear associations between the vasoactive hormones and progression of retinopathy could be detected.