ASSOCIATION OF GESTATIONAL DIABETES WITH ABNORMAL MATERNAL VASCULAR ENDOTHELIAL FUNCTION

Objective To evaluate vascular endothelial function in isolated small arteries from women with gestational diabetes. Methods Small subcutane ous arteries (mean luminal diameter approximate to 250 mu m) were diss ected from biopsies obtained at caesarean section in 14 normotensive w omen with gestational diabetes and in 18 normotensive nondiabetic preg nant women. Vascular function was determined after mounting the arteri es on a small vessel myograph. Results Pre-constricted arteries from g estational diabetic pregnant women demonstrated poor relaxation to ace tylcholine, an endothelium-dependent vasodilator (pEC(50), mean [SE], 6.98 [0.10] vs normal pregnant, 7.28 [0.08], P < 0.03; % maximum relax ation, median [range], 88.2 [42.4-99.4] vs normal pregnant 94.2 [71.8- 100.0], P < 0.01). In the presence of indomethacin relaxation to acety lcholine was similar in both groups suggesting a deficiency in dilator prostaglandin synthesis in the arteries from the diabetic women. The nitric oxide synthase inhibitor N-G-monomethyl-L-arginine further redu ced sensitivity of arteries to acetylcholine but to a similar degree i n both normal pregnant and gestational diabetic women. Relaxation to s odium nitroprusside, an indicator of sensitivity of the vascular smoot h muscle to nitric oxide, was similar in both groups. Conclusions Mate rnal vascular endothelial dysfunction may contribute to the increased incidence of cardiovascular disorders in women with gestational diabet es.