Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy.
We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic hyperinsulinemic clamp in 26 young, healthy subjects and 43 elderly patients with unmedicated essential hypertension and left ventricular hypertrophy. The 3-h Sip correlated strongly with the 2-h M/IG in the patients (r = 0.88, p < 0.001) as well as in the healthy subjects (r = 0.96, p < 0.001) with relatively narrow limits of agreement in the patients. However, during the third hour of insulin infusion, M/IG (10.0 vs 12.21(2) x kg(-1) x min(-1) x mmol(-1), p < 0.001) as well as Sip (7.1 vs 9.41(2) x kg(-1) x min(-1) x mmol(-1), p < 0.001) increased significantly in the patients, but not in the healthy subjects. Because the 2-h M/IG correlated strongly with the 3-h Sip with relatively narrow limits of agreement, it is a good measure of insulin sensitivity. However, a 2-h clamp results in lower insulin sensitivity values in elderly, hypertensive patients due to the fact that steady state is not reached, demonstrating a higher prevalence of insulin resistance in such a population.
Olsen
M H
MH
Department of Clinical Physiology and Nuclear Medicine, Glostrup Hospital, University of Copenhagen, Denmark. mho@dadlnet.dk
Andersen
U B
UB
Wachtell
K
K
Ibsen
H
H
Dige-Petersen
H
H
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism; D006973:Hypertension / Q000097:blood* / Q000378:metabolism*; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000378:metabolism; D007328:Insulin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D007332:Insulin Infusion Systems / Q000592:standards; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D005947:Glucose