Urinary endothelin in adolescents and young adults with
insulin-dependent diabetes mellitus: Relation to urinary albumin, blood
pressure, and other factors
Endothelin (ET) is a potent vasoconstrictive peptide that may play a
role in vascular pathology in general and diabetic nephropathy in
particular. The aim of this study was to investigate (1) alterations of
urinary ET1 (UET1) in adolescents and young adults with
insulin-dependent diabetes mellitus (IDDM) and (2) the relation of UET1
to other indices of diabetic nephropathy and to risk factors of diabetic
angiopathy in general. In 130 IDDM subjects aged 15.2 +/- 4.9 years with
a diabetes duration of 7.3 +/- 5.1 years, UET1 by radioimmunoassay,
urinary albumin by nephelometry, plasma renin by immunoradiometric
assay, hemoglobin A(1c) (HbA(1c)) by high-performance liquid
chromatography, and routine biochemistry analyses were determined.
Forty-eight controls, healthy siblings of the diabetics of comparable
age, were similarly studied. Total 24-hour UET1 excretion was higher in
diabetics than in controls (10,866 +/- 7,270 and 6,598 +/- 3,294 pg/24
h, respectively, P = .000). This difference was also noted if male and
female diabetics were separately compared with controls. In diabetics
with normoalbuminuria (<20 mu g/min), total 24-hour UET1 excretion was
also higher than in controls (P = .002). In diabetics but not in
controls, 24-hour UET1 values were higher in males than in females (P =
.018). In IDDM subjects, UET1 showed a linear relationship with age (P =
.002), urinary albumin (P = .000), serum creatinine (P = .001), systolic
blood pressure (P = .038), triglycerides (P = .003), and HbA(1c) (P =
.041). Multiple regression analysis demonstrated that the variables
interacting independently with UET1 were urinary albumin (P = .003) and
serum creatinine (P = .038). UET1 is elevated early (in adolescence) in
IDDM subjects, and it is positively correlated with the degree of
albuminuria. These data suggest that the amount of UET1 possibly
reflects the severity of diabetic renovascular damage. It may thus be
speculated that UET1 could be used as another index of diabetic
nephropathy or its progress. Copyright (C) 1998 by W.B. Saunders
Company