Plasma endothelin-1 and nitric oxide in children with insulin-dependent diabetes mellitus

ABSTRACT

Dysfunction of vascular endothelium is considered an early step in the development of diabetic complications. To assess plasma endothelin-1 [ET-1] and nitric oxide [NO] levels in children with insulin-dependent diabetes mellitus [IDDM] and their relation to the degree of metabolic control and disease duration. Plasma ET-1 and NO levels were assessed-by enzyme immunoassay-in 34 children with IDDM and compared to 17 healthy controls of matched age and sex. Diabetic patients had higher plasma ET-1 levels compared to controls [median [IQR]=5.9 [4.9-39.2] Vs 4.9 [4.4-6.1] pg/mI, P=0.02]. ET-1 levels were higher in patients with poor and moderate metabolic control when compared to those with ideal control [p=0.004 and 0.001; respectively]. ET-1 levels were positively correlated with NO levels [r=0.48, p=0.004]; HblAc level [r=0.57, P=0,001]; and disease duration [r=0.39, p=0.02]. Although, plasma NO levels in diabetic patients were not significantly different from controls [median [IQR]=24.6 [21.9-30.2] Vs 22.0 [21.0-26.5] umol/L, P 0.09]; NO levels were significantly higher in patients with poor metabolic control when compared to those with ideal control [p<0.001]. In children with IDDM, poor metabolic control and increased disease duration are associated with increased ET-1 production, which may be related to future diabetic complications. The elevated plasma NO levels in poorly controlled patients might mean a compensatory protective response towards increased ET-1 production