Better HbA1c during the first years after diagnosis of type 1 diabetes is associated with residual C peptide 10 years later

Abstract

ObjectiveTo identify the factors associated with residual C peptide production at least 10 years after diagnosis in children and adolescents with type 1 diabetes.Research design and methods73 children and adolescents (<25 years), born in 1988–2005, diagnosed with type 1 diabetes were included during the 4-year study period (2013–2016). At least 10 years after diagnosis, we measured any remaining C peptide concentration using an ultrasensitive C peptide ELISA (≥1.17 pmol/L). The average hemoglobin A1c (HbA1c) was calculated during each of the 10 years after diagnosis and further grand average was calculated for the entire study period.ResultsC peptide was detectable in 38% of participants. The C peptide concentration was 4.3±5.3 pmol/L. At onset of type 1 diabetes, participants were on average approximately 5 years of age, and their average HbA1c was 9.4% (79 mmol/mol). During the first 3 years after diagnosis, HbA1c was lower in the group with detectable C peptide at follow-up ≥10 years later. Moreover, detectable C peptide was more common among female participants. Body mass index SD scores had not increased since the 1-year follow-up, but were higher in patients with measurable C peptide. Nine participants (12%) had been diagnosed with celiac disease and two (3%) with hypothyreosis. Eighteen (25%) participants had retinopathy.ConclusionsChildren and adolescents with detectable C peptide after more than 10 years of diabetes duration were predominantly female and had better HbA1c than others during the first 3 years after diagnosis.