Results from the Diabetes Control and Complications Trial (DCCT) showed that intensive management of hyperglycaemia is associated with slow progression of micro and macrovascular complications (2), even though despite the current use of intensive insulin treatment, the risk of cardiovascular disease (CVD) in patients with T1D still remains high, suggesting the importance of other factors, such as blood pressure, lipids, obesity and smoking (41). The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.