Comment on Russell-Jones et al. Diabetes Care 2017;40:943–950. Comment on Bowering et al. Diabetes Care 2017;40:951–957

We read with interest the recent papers relating to the onset 1 and onset 2 trials (1,2), which compared the clinical efficacy and safety profiles of fast-acting insulin aspart (faster aspart) with insulin aspart (IAsp) in patients with type 1 and type 2 diabetes who concurrently received basal insulin. The authors recognize the importance of lowering postprandial glycemia to achieve HbA1c goals, particularly when fasting glucose is adequately controlled or only modestly elevated. The central hypothesis underlying the trials is that mealtime insulin with a faster action will provide better control of postprandial glycemia and, potentially, HbA1c when used with basal insulin. However, postprandial blood glucose concentrations are determined by glucose disposal and both exogenous and endogenous glucose production, i.e., interrelated …