Screening for type 2 diabetes in obese youth.
OBJECTIVE
To assess available blood tests as potential screening tools for impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM).


METHODS
We studied 468 obese (BMI mean: 34.4 kg/m(2)) children, including a subgroup with serum fasting insulin levels of >15 microIU/mL. Fasting laboratory tests included measurements of serum glucose and insulin, hemoglobin A1c (HbA1c), and 1,5-anhydroglucitol (insulin-resistant subgroup only) levels. An oral glucose-tolerance test was performed on each patient, and 2-hour postload serum glucose and insulin levels were obtained. Fasting blood glucose (BG), Homeostasis Model of Assessment for Insulin Resistance (HOMA-IR), HbA1c, and 1,5-anhydroglucitol values were used as predictors for exceeding various 2-hour BG cut-offs. Receiver operator characteristic curves were fitted to determine area-under-the-curve values as measures of screening efficacy.


RESULTS
In the insulin-resistant subgroup, 3 (2%) patients had T2DM and 23 (12%) had IGT. Optimal sensitivity and specificity to detect T2DM were, respectively, 99% and 96% at HbA1c >or= 6.0%, and 96% and 88% at 1,5-anhydroglucitol < 17.0 microg/mL, with lower values for fasting BG and the HOMA-IR. In the entire study group, 9 (2%) patients had T2DM and 44 (9%) had IGT. Optimal sensitivity and specificity to detect T2DM were, respectively, 86% and 85% at HbA1c levels of 5.7%, 88%, and 93% at a fasting BG level of 104 mg/dL, and 62% and 70% at an HOMA-IR of 7.9.


CONCLUSIONS
HbA1c, 1,5-anhydroglucitol, and fasting BG levels are good predictors of T2DM in obese children, whereas HOMA-IR values are not. HbA1c and 1,5-anhydroglucitol are excellent predictors of T2DM in insulin-resistant obese children.
Shah
Shuchi
S
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9063, USA.
Kublaoui
Bassil M
BM
Oden
Jon D
JD
White
Perrin C
PC
D000293:Adolescent; D000367:Age Factors; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002648:Child; D003847:Deoxyglucose / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D008403:Mass Screening; D009765:Obesity / Q000097:blood / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D013781:Texas
D001786:Blood Glucose; D003847:Deoxyglucose; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human; C006584:1,5-anhydroglucitol