Mh. Olsen et al., Influence of non-steady state during isoglycemic hyperinsulinemic clamp inhypertension - A LIFE substudy, BLOOD PRESS, 8(4), 1999, pp. 207-213
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 (S
ip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic h
yperinsulinemic 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 m
mol(-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 Si
p with relatively narrow limits of agreement, it is a good measure of insul
in sensitivity. However, a 2-h clamp results in lower insulin sensitivity v
alues in elderly, hypertensive patients due to the fact that steady state i
s not reached, demonstrating a higher prevalence of insulin resistance in s
uch a population.