Comparison of Vehicle Delivery Depth Using the NovoFine® 5 mm Needle With or Without a Skin Fold and Inserted at Either 45 or 90 Degrees

Children and adolescents with type 1 diabetes mellitus are required to inject insulin daily. The injection technique should reliably deposit insulin into subcutaneous fat while minimizing inadvertent delivery into either the skin or the underlying muscle, both of which are associated with suboptimal outcomes. The use of shorter, thinner needles reduces the incidence of intramuscular delivery and is associated with reduced discomfort, but increases the risks of both shallow (intradermal) delivery and of loss of insulin through backflow to the skin surface. In the current study, 240 subjects (children and adults) will receive multiple injections of small volumes of sterile air in the thigh and abdomen using 5 mm Novofine® needles, to simulate insulin injections performed at the two sites using various injection techniques (perpendicular or angled needle, with or without skin fold). Ultrasound visualisation of the injected air will allow determination of the incidence of intradermal or intramuscular delivery using the various delivery methods in the trial. In addition, adult subjects will receive injections of a liquid test medium in order to determine the incidence and extent of backflow. Qualitative data on perceived discomfort and information on body composition will also be collected. This investigation will form the basis for recommendations regarding preferred injection technique where 5 mm needles are used.