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Glucose and C-peptide changes in the perionset period of type 1 diabetes in the Diabetes Prevention Trial-Type 1.

Sosenko JM, Palmer JP, Rafkin-Mervis L, Krischer JP, Cuthbertson D, Matheson D, Skyler JS - Diabetes Care (2008)

Bottom Line: Peak C-peptide levels fell substantially between the OGTTs (median change -14.3%, P < 0.001).Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 +/- 1.3 months) was -23.8% (P < 0.001).It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

View Article: PubMed Central - PubMed

Affiliation: Division of Endocrinology, University of Miami, Miami, Florida, USA. jsosenko@med.miami.edu

ABSTRACT

Objective: We examined metabolic changes in the period immediately after the diagnosis of type 1 diabetes and in the period leading up to its diagnosis in Diabetes Prevention Trial-Type 1 (DPT-1) participants.

Research design and methods: The study included oral insulin trial participants and parenteral insulin trial control subjects (n = 63) in whom diabetes was diagnosed by a 2-h diabetic oral glucose tolerance test (OGTT) that was confirmed by another diabetic OGTT within 3 months. Differences in glucose and C-peptide levels between the OGTTs were assessed.

Results: Glucose levels increased at 90 (P = 0.006) and 120 min (P < 0.001) from the initial diabetic OGTT to the confirmatory diabetic OGTT (mean +/- SD interval 5.5 +/- 2.8 weeks). Peak C-peptide levels fell substantially between the OGTTs (median change -14.3%, P < 0.001). Among the 55 individuals whose last nondiabetic OGTT was approximately 6 months before the initial diabetic OGTT, peak C-peptide levels decreased between these two OGTTs (median change -14.0%, P = 0.052). Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 +/- 1.3 months) was -23.8% (P < 0.001). Median rates of change in peak C-peptide levels were 0.00 ng x ml(-1) x month(-1) (P = 0.468, n = 36) from approximately 12 to 6 months before diagnosis, -0.10 ng x ml(-1) x month(-1) (P = 0.059, n = 55) from 6 months before diagnosis to diagnosis, and -0.43 ng x ml(-1) x month(-1) (P = 0.002, n = 63) from the initial diabetic OGTT to the confirmatory diabetic OGTT.

Conclusions: It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

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Related in: MedlinePlus

Association between change in peak C-peptide and time after diagnosis. Shown is the scatter plot for the association between the change in peak C-peptide levels and the time after diagnosis. The amount of decline becomes more substantial with increasing time after diagnosis. (An outlier was removed with a change in peak C-peptide of −8.8 ng/ml and a time after diagnosis of 8.0 weeks [r = −0.31, P = 0.014 with the outlier included.]) When an allowance was made for the peak C-peptide at the first diabetic OGTT, the slope for the difference in peak C-peptide versus time after diagnosis was −0.56 ng · ml−1 · month−1.
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f2: Association between change in peak C-peptide and time after diagnosis. Shown is the scatter plot for the association between the change in peak C-peptide levels and the time after diagnosis. The amount of decline becomes more substantial with increasing time after diagnosis. (An outlier was removed with a change in peak C-peptide of −8.8 ng/ml and a time after diagnosis of 8.0 weeks [r = −0.31, P = 0.014 with the outlier included.]) When an allowance was made for the peak C-peptide at the first diabetic OGTT, the slope for the difference in peak C-peptide versus time after diagnosis was −0.56 ng · ml−1 · month−1.

Mentions: The change in AUC glucose values between the two diabetic OGTTs was positively associated with the length of the interval between them (r = 0.32, P = 0.011), whereas there was an inverse correlation of change of peak C-peptide levels with that interval (r = −0.31, P = 0.014). Thus, the fall in peak C-peptide levels increased with longer intervals. A scatter plot for the association of the change in peak C-peptide levels between the OGTTs and the interval between the diabetic OGTTs (with the removal of an outlier) is shown in Fig. 2. The correlation was almost identical (r = −0.31, P = 0.016) with the outlier excluded. With an allowance for the peak C-peptide levels from the first diabetic OGTT, the slope for the association of change in peak C-peptide levels with the interval between the diabetic OGTTs was −0.56 ng · ml−1 · month−1.


Glucose and C-peptide changes in the perionset period of type 1 diabetes in the Diabetes Prevention Trial-Type 1.

Sosenko JM, Palmer JP, Rafkin-Mervis L, Krischer JP, Cuthbertson D, Matheson D, Skyler JS - Diabetes Care (2008)

Association between change in peak C-peptide and time after diagnosis. Shown is the scatter plot for the association between the change in peak C-peptide levels and the time after diagnosis. The amount of decline becomes more substantial with increasing time after diagnosis. (An outlier was removed with a change in peak C-peptide of −8.8 ng/ml and a time after diagnosis of 8.0 weeks [r = −0.31, P = 0.014 with the outlier included.]) When an allowance was made for the peak C-peptide at the first diabetic OGTT, the slope for the difference in peak C-peptide versus time after diagnosis was −0.56 ng · ml−1 · month−1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2571043&req=5

f2: Association between change in peak C-peptide and time after diagnosis. Shown is the scatter plot for the association between the change in peak C-peptide levels and the time after diagnosis. The amount of decline becomes more substantial with increasing time after diagnosis. (An outlier was removed with a change in peak C-peptide of −8.8 ng/ml and a time after diagnosis of 8.0 weeks [r = −0.31, P = 0.014 with the outlier included.]) When an allowance was made for the peak C-peptide at the first diabetic OGTT, the slope for the difference in peak C-peptide versus time after diagnosis was −0.56 ng · ml−1 · month−1.
Mentions: The change in AUC glucose values between the two diabetic OGTTs was positively associated with the length of the interval between them (r = 0.32, P = 0.011), whereas there was an inverse correlation of change of peak C-peptide levels with that interval (r = −0.31, P = 0.014). Thus, the fall in peak C-peptide levels increased with longer intervals. A scatter plot for the association of the change in peak C-peptide levels between the OGTTs and the interval between the diabetic OGTTs (with the removal of an outlier) is shown in Fig. 2. The correlation was almost identical (r = −0.31, P = 0.016) with the outlier excluded. With an allowance for the peak C-peptide levels from the first diabetic OGTT, the slope for the association of change in peak C-peptide levels with the interval between the diabetic OGTTs was −0.56 ng · ml−1 · month−1.

Bottom Line: Peak C-peptide levels fell substantially between the OGTTs (median change -14.3%, P < 0.001).Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 +/- 1.3 months) was -23.8% (P < 0.001).It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

View Article: PubMed Central - PubMed

Affiliation: Division of Endocrinology, University of Miami, Miami, Florida, USA. jsosenko@med.miami.edu

ABSTRACT

Objective: We examined metabolic changes in the period immediately after the diagnosis of type 1 diabetes and in the period leading up to its diagnosis in Diabetes Prevention Trial-Type 1 (DPT-1) participants.

Research design and methods: The study included oral insulin trial participants and parenteral insulin trial control subjects (n = 63) in whom diabetes was diagnosed by a 2-h diabetic oral glucose tolerance test (OGTT) that was confirmed by another diabetic OGTT within 3 months. Differences in glucose and C-peptide levels between the OGTTs were assessed.

Results: Glucose levels increased at 90 (P = 0.006) and 120 min (P < 0.001) from the initial diabetic OGTT to the confirmatory diabetic OGTT (mean +/- SD interval 5.5 +/- 2.8 weeks). Peak C-peptide levels fell substantially between the OGTTs (median change -14.3%, P < 0.001). Among the 55 individuals whose last nondiabetic OGTT was approximately 6 months before the initial diabetic OGTT, peak C-peptide levels decreased between these two OGTTs (median change -14.0%, P = 0.052). Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 +/- 1.3 months) was -23.8% (P < 0.001). Median rates of change in peak C-peptide levels were 0.00 ng x ml(-1) x month(-1) (P = 0.468, n = 36) from approximately 12 to 6 months before diagnosis, -0.10 ng x ml(-1) x month(-1) (P = 0.059, n = 55) from 6 months before diagnosis to diagnosis, and -0.43 ng x ml(-1) x month(-1) (P = 0.002, n = 63) from the initial diabetic OGTT to the confirmatory diabetic OGTT.

Conclusions: It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

Show MeSH
Related in: MedlinePlus