Comparison of Cystic Fibrosis–Related Diabetes With Type 1 Diabetes Based on a German/Austrian Pediatric Diabetes Registry

Abstract

OBJECTIVE The prevalence of cystic fibrosis–related diabetes (CFRD) has increased with improved life expectancy of patients. Clinical and care characteristics were compared with type 1 diabetes mellitus (T1DM) in a multicenter analysis of pediatric data. RESEARCH DESIGN AND METHODS Auxological and treatment data from 47,227 patients aged younger than 21 years with CFRD or T1DM in the German/Austrian Diabetes Prospective Documentation Initiative registry were analyzed by multivariable mixed regression modeling. RESULTS Diabetes onset (mean [interquartile range]) occurred later in individuals with CFRD (14.5 [11.8–16.3] years) than in individuals with T1DM (8.5 [4.9–11.8] years), with female preponderance in CFRD (59.1% vs. 47.5%; P < 0.01). CFRD patients had lower BMI standard deviation scores (−0.85 [−1.59 to −0.12] vs. +0.52 [−0.10 to +1.16]; P < 0.01) and lower HbA1c (6.87% vs. 7.97%; P < 0.01). Self-monitoring of blood glucose was more frequent in patients with T1DM (4.5 vs. 3.5; P < 0.01); 72% of CFRD patients received insulin. In insulin-treated patients, insulin dosage adjusted for age, sex, and diabetes duration differed significantly (T1DM: 0.79 IE per kilogram of body weight; CFRD: 0.83 IE per kilogram of body weight). Use of short-acting and long-acting insulin analogs was significantly more frequent in T1DM (47% vs. 39% and 37% vs. 28%; both P < 0.05). Metabolic control in CFRD patients without insulin was better compared with CFRD on insulin (HbA1c: 6.00 vs. 7.12; P < 0.01), but duration of disease was significantly shorter (0.8 years [0.1–2.4] compared with 2.4 years [0.6–4.6]). There was no significant difference for BMI standard deviations scores between CFRD patients with or without insulin treatment. CONCLUSIONS Pediatric patients with CFRD show clear auxological and metabolic differences from those with T1DM, with different treatment choices.