Demographic and clinical characteristics of a population-based pediatric cohort of type 1 and type 2 diabetes in Western Australia (1999–2019)

Objectives: To determine demographic and clinical characteristics of youth diagnosed with type 1 (T1D) or type 2 (T2D) diabetes aged ≤15 years from 1999 to 2019 in Western Australia, and examine time to first diagnosis of diabetes complications. 

Methods: A retrospective cohort study was conducted of patients identified from the population-based, prospective Western Australian Children's Diabetes Database and longitudinal data extracted for available demographic and clinical variables. Patients were followed from diagnosis to transition to adult services, death, or December 31, 2019. Cox proportional hazards regression models were used to analyse time to first diagnosis of hypertension, high cholesterol or microalbuminuria, after adjusting for sex, age at diagnosis, time period of diagnosis, hemoglobin A1_c, and body max index Z-score. 

Results: 2438 eligible patients were identified (2209 [91%] T1D: 229 [9%] T2D). The mean age at diagnosis was lower in patients with T1D (8.5 [±4.0] vs. 12.7 [±2.0] years). A higher proportion of patients with T2D were female (58% vs. 47%) and of Aboriginal ethnicity (59% vs. 2%). The median HbA1c (interquartile range) at diagnosis was lower 8.9% [6.7, 11.5] (74 mmol/mol [50, 102]) versus 11.6% [10.1, 13.3] (103 mmol/mol [87, 122]) and mean body max index Z-score higher (2.05 [±0.66] vs. 0.37 [±0.95]), in patients with T2D compared to T1D. Patients with T2D had a higher risk of hypertension, high cholesterol, and microalbuminuria (aHR 3.39 [95%CI:2.04, 5.63], 2.69 [95%CI:1.21, 5.98], and 19.79 [95%CI:10.99, 35.64] respectively).