Classification of distinct baseline insulin infusion patterns in children and adolescents with type 1 diabetes on continuous subcutaneous insulin infusion therapy

OBJECTIVE - We hypothesized systematic differences in the patterns of programmed basal insulin infusion rates in children and adolescents with type 1 diabetes on continuous subcutaneous insulin infusion (CSII). We aimed at classification of basal insulin infusion rate regimens and comparing patients' underlying clinical characteristics. RESEARCH DESIGN AND METHODS - The German/Austrian diabetes data acquisition system for prospective surveillance database for quality control and scientific surveys in pediatric diabetology served as the primary data source. Latest(September 2004) basal insulin infusion rates of all 1,248 patients with type 1 diabetes on CSII (0.38-18 years) were analyzed (dataset 1). Basal insulin infusion rates per hour were expressed relative to mean basal insulin infusion rates per 24 h. Unsupervised clustering was used to classify basal insulin infusion rate patterns. Clinical characteristics of patients falling into distinct basal insulin infusion rate clusters were compared by Kruskal-Wallis test. Changes of basal insulin infusion rates in 64 patients were followed from initial settings before CSII to latest programming in an independent dataset 2. RESULTS - Seven different basal insulin infusion rate patterns occurred in dataset 1. A dawn-dusk pattern was used in 708 patients (14.9 +/- 2.4 years) with the peak basal insulin infusion rate at 5 A.M. Additional patterns showed only one basal insulin infusion rate oscillation per 24 h with a backshift of peak basal insulin infusion rates in younger children (P < 0.000001) (1 A.M.: n = 152, 12.4 years and 9 P.m.: n = 117, 8.9 years). All but two patients in dataset 2 were initially set on dawn-dusk patterns but showed a comparable diversification of basal insulin infusion rates during follow-up with backshift of peak basal insulin infusion rates in younger children (P < 0.01). CONCLUSIONS - Pediatric diabetologists shape distinct basal insulin infusion rate profiles during treatment of CSII patients, mainly reflecting differences in age. Our data strongly suggest that age-dependent endocrine changes during childhood (e.g., puberty) affect circadian distribution of insulin needs in CSII, which should be kept in mind when considering basal insulin infusion rate strategies in children and adolescents.