Estimates of insulin sensitivity using glucose and C-Peptide from the hyperglycemia and adverse pregnancy outcome glucose tolerance test.
OBJECTIVE To determine if glucose and C-peptide values obtained as part of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study could be used to estimate insulin sensitivity during late pregnancy. RESEARCH DESIGN AND METHODS A total of 78 women enrolled in the HAPO study were recruited for this ancillary study. Venous plasma samples were drawn after an 8- to 10-h fast (time 0) and at 30, 60, 90, and 120 min after a 75-g glucose challenge, which was performed at 24-32 weeks' gestation. Samples were analyzed for plasma glucose, insulin, and C-peptide. Insulin sensitivity was estimated using the established Matsuda and DeFronzo insulin sensitivity index for oral glucose tolerance tests (IS(OGTT)). Insulin sensitivity was also calculated from two other commonly used indexes of insulin sensitivity (that for homeostasis model assessment [IS(HOMA)] and that for quantitative insulin sensitivity check index [IS(QUICKI)]). A new insulin sensitivity index was calculated using the glucose and C-peptide concentrations at 0 and 60 min to derive IS(HOMA C-pep), IS(QUICKI C-pep), and IS(OGTT C-pep). These indexes were then correlated with insulin sensitivity estimated from the IS(OGTT). RESULTS The strongest correlation with the IS(OGTT) was obtained for IS(OGTT C-pep) (r = 0.792, P < 0.001). Further, the correlations of IS(HOMA) (C-pep) and IS(QUICKI C-pep) with IS(OGTT) were also significant (r = 0.676, P < 0.001 and r = 0.707, P < 0.001, respectively). CONCLUSIONS These data suggest that calculated IS(OGTT C-pep) is an excellent predictor of insulin sensitivity in pregnancy and can be used to estimate insulin sensitivity in over 25,000 women participating in the HAPO study.
Radaelli
Tatjana
T
Department of Obstetrics and Gynecology, IRCCS Ospedale Policlinico, Mangiagalli and Regina Elena, University of Milan, Milan, Italy.
Farrell
Kristen Anne
KA
Huston-Presley
Larraine
L
Amini
Saeid Baradaran
SB
Kirwan
John Patrick
JP
McIntyre
Harold David
HD
Catalano
Patrick Michael
PM
D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D002096:C-Peptide / Q000097:blood*; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005951:Glucose Tolerance Test; D006305:Health Status Indicators; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000139:chemically induced; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D055815:Young Adult
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin