Feasibility study of vertical subcutaneous injection of insulin with an insulin pen injector in diabetic patients with normal body mass index.

This study explored the feasibility of vertical insulin injection with an insulin pen injector in 40 Chinese diabetic outpatients with a normal body mass index. The patients, who received insulin in the hospital clinic, were assessed for abdominal subcutaneous fat thickness and distribution at four abdominal points using ultrasonography. Abdominal subcutaneous fat thickness and distribution were found to be heterogeneous and to differ significantly at these four points. Abdominal subcutaneous fat thickness was < 5 mm in nine of the 40 patients. In patients with abdominal subcutaneous fat thickness of < 5 mm, vertical insulin injection risks injecting into the muscle layer and is, therefore, not desirable. Vertical injection into pinched skin with a rotary syringe is safe and effective in such patients.