Influence of glycaemic management and BMI on cardiac autonomic markers in children with type 1 diabetes: a prospective cohort study

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.