Age and sex mark clinical differences in the presentation of pediatric type 1 diabetes mellitus.

Objectives: Type 1 diabetes mellitus (T1D) is a heterogeneous condition. We aimed to study the associations between age and sex with clinical characteristics at the onset of pediatric T1D.

Methods: A secondary analysis was conducted on data collected retrospectively from 706 children newly diagnosed with T1D at a large tertiary hospital in southeastern USA. Age (stratified across three cohorts from 0.84 to 18.08 years), sex, and their interaction were compared for associations with clinical characteristics of T1D at presentation by multivariable regression analyses and pairwise comparisons.

Results: Within the participants (mean age 9.71 (SD 4.10), 48.3 % female, 21.0 % Hispanic, 15.3 % non-Hispanic black and 58.7 % non-Hispanic white), children under 6 years had higher glucose (p<0.001), lower hemoglobin A1c (HbA1c) (p<0.001), and lower C-peptide (p<0.001) than the older age groups. Diabetic ketoacidosis (DKA) was more prevalent in the youngest (p=0.005) and the intermediate-aged cohorts (p=0.005), compared to the oldest group. Among the children with DKA, bicarbonate was lower in the youngest (p<0.001) and middle cohorts (p=0.013), compared to the oldest group. Younger age was associated with higher prevalence of insulin autoantibodies (IAA; p<0.001) and IA-2 autoantibodies (IA-2A; p=0.006). Males had higher glucose (p=0.001), but lower HbA1c (p=0.003), lower C-peptide (p<0.001), and lower GAD autoantibody (GADA) prevalence (p=0.001) than females. There was no significant interaction between age and sex.

Conclusions: In children with new onset T1D, younger age and male sex were associated with findings suggestive of more rapid and aggressive T1D preclinical course, including poorer beta-cell function, and distinct islet autoantibody profiles.