Fasting and OGTT-derived measures of insulin resistance as compared with the euglycemic-hyperinsulinemic clamp in nondiabetic Finnish offspring of type 2 diabetic individuals.
BACKGROUND
It remains to be established which surrogate marker is the most predictive of insulin resistance.


OBJECTIVE
We evaluated the incremental value of the Matsuda insulin sensitivity index (ISI) to homeostasis model assessment of insulin resistance (HOMA-IR) for detecting insulin resistance.


METHODS
This was a cross-sectional analysis of the EUGENE2 Kuopio cohort.


METHODS
Participants included 266 nondiabetic Finnish offspring of type 2 diabetic individuals (aged 24-50 years).


METHODS
Insulin resistance (the lowest whole-body glucose uptake quartile) was measured by the euglycemic-hyperinsulinemic clamp. We used the area under the receiver operating characteristic curve, an insensitive method to model improvement. Reclassification was assessed by the net reclassification improvement and integrated discrimination improvement. We generated four strata using, as cut points, the 0.05, 0.25, and 0.70 probabilities of having insulin resistance. These were observed probabilities at body mass index of 20, 27, and 35 kg/m(2), respectively.


RESULTS
The area under the receiver operating characteristic curve of the Matsuda ISI based on 5 time points (0, 30, 60, 90, and 120 minutes) did not differ statistically from that of HOMA-IR (0.897 and 0.875, P = .080). However, the Matsuda ISI added incremental value to HOMA-IR for the detection of insulin-resistant individuals (net reclassification improvement, 26.2%, P < .001; integrated discrimination improvement, 6.3%, P < .001). A modified Matsuda ISI based on 4 time points (0, 30, 60, and 120 minutes) yielded similar results.


CONCLUSIONS
The Matsuda ISI has additional value for the detection of insulin resistance beyond the ability of HOMA-IR. The Matsuda ISI reclassifies a net of 26% of individuals more appropriately.
Department of Medicine (C.L., S.M.H.), University of Texas Health Science Center, San Antonio, Texas 78229; and Department of Medicine (A.S., J.K., M.L.), University of Eastern Finland, Kuopio 70211, Finland.
Carlos
C
Lorenzo
Steven M
SM
Haffner
Alena
A
Stančáková
Johanna
J
Kuusisto
Markku
M
Laakso
D000328:Adult; D016241:Child of Impaired Parents; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005215:Fasting / Q000097:blood*; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult