Endogenous insulin modulates circulating endothelin-1 concentrations in humans.
OBJECTIVE
To assess the effect of oral glucose loading on plasma endothelin-1 (ET-1) levels in humans.


METHODS
A total of 75 g D-glucose was given orally to 14 nonobese nondiabetic essential hypertensive subjects (eight men and six women, mean age 43.1 +/- 3.0 years) and eight normotensive subjects (four men and four women, mean age 45.2 +/- 4.1 years). Blood samples for plasma ET-1 measurement were drawn every 30 min for 2 h and then at 180 and 240 min.


RESULTS
After glucose load, insulin increased more significantly in hypertensive subjects than in normotensive subjects at times 60 (P = 0.004) and 90 (P = 0.001) min. Glucose loading was followed by a mild but significant increase in circulating ET-1 levels in both groups (hypertensive subjects, from 0.87 +/- 0.25 pg/ml at time 0 to 1.64 +/- 0.33 pg/ml at 120 min and 1.74 +/- 0.38 pg/ml at 180 min, P < 0.05; normotensive subjects, from 0.82 +/- 0.38 pg/ml at time 0 to 1.42 +/- 0.18 pg/ml at 180 min, P < 0.05). Whereas baseline ET-1 levels were similar between the two groups, postload ET-1 levels were higher in hypertensive subjects than in normotensive subjects (P = 0.003 at 120 min; P = 0.04 at 180 min).


CONCLUSIONS
This study indicates that significant changes in circulating ET-1 levels occur after oral glucose loading, probably due to a glucose-induced increment in endogenous insulin concentration.
Ferri
C
C
University La Sapienza Institute of I Clinica Medica, Andrea Cesalpino Foundation, Rome, Italy.
Bellini
C
C
Desideri
G
G
De Mattia
G
G
Santucci
A
A
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D003920:Diabetes Mellitus / Q000235:genetics; D004040:Dietary Carbohydrates; D016232:Endothelins / Q000097:blood*; D005260:Female; D005947:Glucose; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000235:genetics / Q000503:physiopathology; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013997:Time Factors
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D016232:Endothelins; D007328:Insulin; D005947:Glucose