Younger Age, Female Sex, and HbA1c Linked to C-Peptide Decline in Pediatric T1D

little girl with diabetes at doctor
Investigators sought to determine whether younger age at diagnosis, female sex, and higher weight z score and HbA1c are risk factors for C-peptide decline after new onset of pediatric type 1 diabetes.

Decline in C-peptide, a measurement of pancreatic beta cell function and endogenous insulin secretion, is associated with younger age, female sex, higher weight, and higher glycated hemoglobin (HbA1c) in young children diagnosed with type 1 diabetes (T1D). This is according to study results published in the Journal of Clinical Endocrinology and Metabolism.

The observational study, conducted across academic medical centers in the United States and Europe, included 57 participants from The Environmental Determinants of Diabetes in the Young (TEDDY) trial. Researchers enrolled participants in TEDDY at age 3 months and followed them until T1D diagnosis. They recruited an additional 56 age-matched control participants from the community who had been diagnosed with T1D and enrolled them in the study.

The mean age of TEDDY participants at time of T1D diagnosis was 6.5 plus or minus 1.8 years, with no difference between the TEDDY and community groups (P =.378).

Investigators administered a mixed meal tolerance test, consisting of a standardized liquid protein meal, to measure the area under the curve (AUC) C-peptide at 1, 3, 6, 12, and 24 months after the T1D diagnosis.

There was no difference between the TEDDY participants and community control participants in terms of the adjusted slopes of AUC C-peptide decline (P =.21). In the multivariate analysis, factors significantly associated with higher rate of C-peptide decline at 3 months after T1D diagnosis included younger age (P =.001), female sex (P =.017), and higher weight z score (P =.009). In addition, higher HbA1c was an independent factor associated with higher C-peptide loss at 3 months after T1D diagnosis (P =.005).

Limitations of the study include the small sample size as well as the relatively short postdiagnosis follow-up period.

The researchers concluded that the findings from their study suggest that “metabolic factors could also play a role in preservation of beta-cell function” in young children with T1D.


Steck AK, Liu X, Krischer JP, et al. Factors associated with decline of C-peptide in a cohort of young children diagnosed with type 1 diabetes. Published online October 9, 2020. J Clin Endocrinol Metab. doi: 10.1210/clinem/dgaa715