Indices of insulin sensitivity and secretion from a standard liquid meal test in subjects with type 2 diabetes, impaired or normal fasting glucose.
BACKGROUND
To provide an initial evaluation of insulin sensitivity and secretion indices derived from a standard liquid meal tolerance test protocol in subjects with normal (NFG), impaired fasting glucose (IFG) or type 2 diabetes mellitus.


METHODS
Areas under the curve (AUC) for glucose, insulin and C-peptide from pre-meal to 120 min after consumption of a liquid meal were calculated, as were homeostasis model assessments of insulin resistance (HOMA2-IR) and the Matsuda index of insulin sensitivity.


RESULTS
Subjects with NFG (n = 19), IFG (n = 19), and diabetes (n = 35) had mean +/- SEM HOMA2-IR values of 1.0 +/- 0.1, 1.6 +/- 0.2 and 2.5 +/- 0.3 and Matsuda insulin sensitivity index values of 15.6 +/- 2.0, 8.8 +/- 1.2 and 6.0 +/- 0.6, respectively. The log-transformed values for these variables were highly correlated overall and within each fasting glucose category (r = -0.91 to -0.94, all p < 0.001). Values for the product of the insulin/glucose AUC ratio and the Matsuda index, an indicator of the ability of the pancreas to match insulin secretion to the degree of insulin resistance, were 995.6 +/- 80.7 (NFG), 684.0 +/- 57.3 (IFG) and 188.3 +/- 16.1 (diabetes) and discriminated significantly between fasting glucose categories (p < 0.001 for each comparison).


CONCLUSIONS
These results provide initial evidence to support the usefulness of a standard liquid meal tolerance test for evaluation of insulin secretion and sensitivity in clinical and population studies.
Maki
Kevin C
KC
Provident Clinical Research, Bloomington, IN, USA. kmaki@providentcrc.com
McKenney
James M
JM
Farmer
Mildred V
MV
Reeves
Matthew S
MS
Dicklin
Mary R
MR
D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D002096:C-Peptide / Q000032:analysis / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000379:methods*; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin