Type 1 diabetes occurs when the body produces no insulin because of autoimmune destruction of the pancreatic cells that produce it. It can occur at any age, but usually develops before the age of 40, often during teenage years.

Someone who has type 1 diabetes will need to take insulin injections for life and in order to reduce their risk of developing complications, must ensure that their blood glucose levels are as good as possible by balancing their insulin doses, diet and activity, as well as carrying out regular blood testing.

The primary diabetes outcome is glycaemic control, as measured by a blood test (glycosylated haemoglobin or HbA1c) that indicates average plasma glucose for the previous 2-3 months.