Abstract
Background: In new onset type 1 diabetes (T1D), overall C-peptide measures such as area under the curve (AUC) C-peptide and peak C-peptide are useful for estimating the extent of β-cell dysfunction, and for assessing responses to intervention therapy. However, measures of the timing of C-peptide responsiveness could have additional value. Objectives: We assessed the contribution of the timing of C-peptide responsiveness during oral glucose tolerance tests (OGTTs) to hemoglobin A1c (HbA1c) variation at T1D diagnosis. Methods: We analyzed data from 85 individuals <18 years with OGTTs and HbA1c measurements at diagnosis. Overall [AUC and peak C-peptide] and timing measures [30-0 minute C-peptide (early); 60 to 120 minute C-peptide sum-30 minutes (late); 120/30 C-peptide; time to peak C-peptide] were utilized. Results: At diagnosis, the mean (±SD) age was 11.2 ± 3.3 years, body mass index (BMI)-z was 0.4 ± 1.1, 51.0% were male. The average HbA1c was 43.54 ± 8.46 mmol/mol (6.1 ± 0.8%). HbA1c correlated inversely with the AUC C-peptide (P < 0.001), peak C-peptide (P < 0.001), early and late C-peptide responses (P < 0.001 each), and 120/30 C-peptide (P < 0.001). Those with a peak C-peptide occurring at ≤60 minutes had higher HbA1c values than those with peaks later (P = 0.003). HbA1c variance was better explained with timing measures added to regression models (R 2 = 11.6% with AUC C-peptide alone; R 2 = 20.0% with 120/30 C-peptide added; R 2 = 13.7% with peak C-peptide alone, R 2 = 20.4% with timing of the peak added). Similar associations were seen between the 2-hour glucose and the C-peptide measures. Conclusions: These findings show that the addition of timing measures of C-peptide responsiveness better explains HbA1c variation at diagnosis than standard measures alone.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 408-413 |
| Number of pages | 6 |
| Journal | Pediatric Diabetes |
| Volume | 20 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jun 1 2019 |
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Keywords
- C-peptide
- glycemia
- HbA1c
- OGTT
- type 1 diabetes
ASJC Scopus subject areas
- Internal Medicine
- Pediatrics, Perinatology, and Child Health
- Endocrinology, Diabetes and Metabolism
Cite this
Associations of HbA1c with the timing of C-peptide responses during the oral glucose tolerance test at the diagnosis of type 1 diabetes. / Type 1 Diabetes Trial Net and Diabetes Prevention Trial-Type-1 (DPT-1) Study Groups.
In: Pediatric Diabetes, Vol. 20, No. 4, 01.06.2019, p. 408-413.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Associations of HbA1c with the timing of C-peptide responses during the oral glucose tolerance test at the diagnosis of type 1 diabetes
AU - Type 1 Diabetes Trial Net and Diabetes Prevention Trial-Type-1 (DPT-1) Study Groups
AU - Ismail, Heba M.
AU - Evans-Molina, Carmella
AU - DiMeglio, Linda A.
AU - Becker, Dorothy J.
AU - Libman, Ingrid
AU - Sims, Emily K.
AU - Boulware, David
AU - Herold, Kevan C.
AU - Rafkin, Lisa
AU - Skyler, Jay S
AU - Cleves, Mario A.
AU - Palmer, Jerry
AU - Sosenko, Jay M
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Background: In new onset type 1 diabetes (T1D), overall C-peptide measures such as area under the curve (AUC) C-peptide and peak C-peptide are useful for estimating the extent of β-cell dysfunction, and for assessing responses to intervention therapy. However, measures of the timing of C-peptide responsiveness could have additional value. Objectives: We assessed the contribution of the timing of C-peptide responsiveness during oral glucose tolerance tests (OGTTs) to hemoglobin A1c (HbA1c) variation at T1D diagnosis. Methods: We analyzed data from 85 individuals <18 years with OGTTs and HbA1c measurements at diagnosis. Overall [AUC and peak C-peptide] and timing measures [30-0 minute C-peptide (early); 60 to 120 minute C-peptide sum-30 minutes (late); 120/30 C-peptide; time to peak C-peptide] were utilized. Results: At diagnosis, the mean (±SD) age was 11.2 ± 3.3 years, body mass index (BMI)-z was 0.4 ± 1.1, 51.0% were male. The average HbA1c was 43.54 ± 8.46 mmol/mol (6.1 ± 0.8%). HbA1c correlated inversely with the AUC C-peptide (P < 0.001), peak C-peptide (P < 0.001), early and late C-peptide responses (P < 0.001 each), and 120/30 C-peptide (P < 0.001). Those with a peak C-peptide occurring at ≤60 minutes had higher HbA1c values than those with peaks later (P = 0.003). HbA1c variance was better explained with timing measures added to regression models (R 2 = 11.6% with AUC C-peptide alone; R 2 = 20.0% with 120/30 C-peptide added; R 2 = 13.7% with peak C-peptide alone, R 2 = 20.4% with timing of the peak added). Similar associations were seen between the 2-hour glucose and the C-peptide measures. Conclusions: These findings show that the addition of timing measures of C-peptide responsiveness better explains HbA1c variation at diagnosis than standard measures alone.
AB - Background: In new onset type 1 diabetes (T1D), overall C-peptide measures such as area under the curve (AUC) C-peptide and peak C-peptide are useful for estimating the extent of β-cell dysfunction, and for assessing responses to intervention therapy. However, measures of the timing of C-peptide responsiveness could have additional value. Objectives: We assessed the contribution of the timing of C-peptide responsiveness during oral glucose tolerance tests (OGTTs) to hemoglobin A1c (HbA1c) variation at T1D diagnosis. Methods: We analyzed data from 85 individuals <18 years with OGTTs and HbA1c measurements at diagnosis. Overall [AUC and peak C-peptide] and timing measures [30-0 minute C-peptide (early); 60 to 120 minute C-peptide sum-30 minutes (late); 120/30 C-peptide; time to peak C-peptide] were utilized. Results: At diagnosis, the mean (±SD) age was 11.2 ± 3.3 years, body mass index (BMI)-z was 0.4 ± 1.1, 51.0% were male. The average HbA1c was 43.54 ± 8.46 mmol/mol (6.1 ± 0.8%). HbA1c correlated inversely with the AUC C-peptide (P < 0.001), peak C-peptide (P < 0.001), early and late C-peptide responses (P < 0.001 each), and 120/30 C-peptide (P < 0.001). Those with a peak C-peptide occurring at ≤60 minutes had higher HbA1c values than those with peaks later (P = 0.003). HbA1c variance was better explained with timing measures added to regression models (R 2 = 11.6% with AUC C-peptide alone; R 2 = 20.0% with 120/30 C-peptide added; R 2 = 13.7% with peak C-peptide alone, R 2 = 20.4% with timing of the peak added). Similar associations were seen between the 2-hour glucose and the C-peptide measures. Conclusions: These findings show that the addition of timing measures of C-peptide responsiveness better explains HbA1c variation at diagnosis than standard measures alone.
KW - C-peptide
KW - glycemia
KW - HbA1c
KW - OGTT
KW - type 1 diabetes
UR - http://www.scopus.com/inward/record.url?scp=85064502048&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85064502048&partnerID=8YFLogxK
U2 - 10.1111/pedi.12845
DO - 10.1111/pedi.12845
M3 - Article
C2 - 30891858
AN - SCOPUS:85064502048
VL - 20
SP - 408
EP - 413
JO - Pediatric Diabetes
JF - Pediatric Diabetes
SN - 1399-543X
IS - 4
ER -