Abstract
AIMS/HYPOTHESIS: Our aim was to examine the presence of subclinical cardiovascular autonomic neuropathy (CAN) in a cohort of children with well-regulated type 1 diabetes by measuring baroreceptor sensitivity (BRS), QT variability index (QTVI) and heart rate variability (HRV). METHODS: Forty-five children (aged 6-15.99 years) with a type 1 diabetes duration of ≥5 years, and 37 healthy control children were included at baseline; and 28 and 18 children, respectively, were included at 2 year follow-up. Cardiac BRS, QTVI and HRV were measured and anthropometrical data and blood samples were collected from all study participants. Longitudinal HbA(1c) values from 3 months after type 1 diabetes diagnosis and continuous glucose monitoring data from the children with type 1 diabetes were also collected. RESULTS: Time in normoglycaemia (TING) increased significantly from 42% to 48% between baseline and 2 year follow-up (p=0.042). No difference in BRS, QTVI or HRV were found between the study groups at baseline or follow-up. Children with type 1 diabetes with a BMI z score ≥1 showed higher QTVI compared with either lean children with diabetes or healthy control children. QTVI correlated with type 1 diabetes duration, longitudinal HbA(1c) AUC and cystatin C in children with type 1 diabetes at baseline, and with CV at follow-up. (r=-0.447 p=0.004, r=-0.376 p=0.017, r=-323 p=0.048, and r=0.568 p=0.01, respectively). There was also a correlation between the increase in TING between the study visits and BRS at follow-up in children with type 1 diabetes (r=0.524 p=0.031). CONCLUSIONS/INTERPRETATION: In this well-regulated type 1 diabetes cohort we did not find manifest signs of CAN in children with type 1 diabetes. These are promising findings and should motivate further to keep striving for normoglycaemia in paediatric diabetes care. Children with both type 1 diabetes and overweight seem more susceptible to early development of CAN and might benefit from earlier and more intensive preventive targeting.