Interpretation: The study suggests an increase in the incidence of pediatric T1D in Lombardy throughout the past five years. Pandemic waves may have affected the clinical presentation at onset.

No abstract

Objective: Transient neonatal diabetes mellitus (TNDM) is caused by activating mutations in ABCC8 and KCNJ11 genes (KATP/TNDM) or by chromosome 6q24 abnormalities (6q24/TNDM). We wanted to assess whether these different genetic aetiologies result in distinct clinical features. Design: Retrospective analysis of the Italian data set of patients with TNDM. Methods: Clinical features and treatment of 22 KATP/ TNDM patients and 12 6q24/TNDM patients were compared. Results: Fourteen KATP/TNDM probands had a carrier parent with abnormal glucose values, four patients with 6q24 showed macroglossia and/or umbilical hernia. Median age at diabetes onset and birth weight were lower in patients with 6q24 (1 week; -2.27 SD) than those with KATP mutations (4.0 weeks; -1.04 SD) (p=0.009 and p=0.007, respectively). Median time to remission was longer in KATP/TNDM than 6q24/TNDM (21.5 vs 12 weeks) (p=0.002). Two KATP/TNDM patients entered diabetes remission without pharmacological therapy. A proband with the ABCC8/L225P variant previously associated with permanent neonatal diabetes entered 7-year long remission after 1 year of sulfonylurea therapy. Seven diabetic individuals with KATP mutations were successfully treated with sulfonylurea monotherapy; four cases with relapsing 6q24/TNDM were treated with insulin, metformin or combination therapy. Conclusions: If TNDM is suspected, KATP genes should be analyzed first with the exception of patients with macroglossia and/or umbilical hernia. Remission of diabetes without pharmacological therapy should not preclude genetic analysis. Early treatment with sulfonylurea may induce long-lasting remission of diabetes in patients with KATP mutations associated with PNDM. Adult patients carrying KATP/TNDM mutations respond favourably to sulfonylurea monotherapy.

The prevalence of obesity, according to sex and pubertal stage, and the correlations between obesity and metabolic data were investigated in 286 diabetic patients (164 boys, 122 girls) with mean (SD) age 15-3 (3.2) years and mean (SD) duration of diabetes 7*5 (4.1) years. Prevalence of obesity according to the body mass index (BMI) criteria was 6-3 %. Girls were more often obese than boys but the prevalence approached statistical significance only for the BMI criteria, at 9-8% v 3.7% (x2=3 5