Intensive insulin therapy improves endothelial function and microvascular reactivity in young people with type 1 diabetes

Aims/hypothesis Macrovascular disease is an important cause of the increased morbidity and mortality rates associated with type 1 diabetes, and this vascular impairment begins in childhood. The aim of this study was to determine whether introducing intensive diabetes management [intensive insulin therapy (IIT) and 'Sweet Talk' text-messaging support] produces measurable improvements in endothelial function.

Methods One hundred and twenty-six patients fulfilled the eligibility criteria (type 1 diabetes for >1 year; on conventional insulin therapy (CIT); aged between 8 and 18 years), of whom 92 enrolled. Patients were randomised to group 1, CIT only (n=28); group 2, CIT and Sweet Talk (n=33); or group 3, IIT and Sweet Talk (n=31). Vascular assessments (including measures of endothelial damage, activation, dysfunction and oxidative stress) and HbA(1c) were performed at baseline and repeated after 12 months of the study.

Results Glycaemic control deteriorated in patients on CIT, but improved significantly in patients allocated to IIT (p=0.007). IIT was associated with significantly greater improvements in E-selectin (p<0.0001) than CIT (group 1, p=0.026 and group 2, p=0.053). Vascular responses to acetylcholine improved in patients on IIT (p=0.017), but not in patients receiving CIT. These changes were all independent of HbA(1c) level.

Conclusions/interpretation IIT appears to be associated with improvements in vascular markers, independently of changes in HbA(1c), suggesting that IIT may confer vascular protection in addition to improving glycaemic control.