INS and diabetes mellitus: The impaired action of insulin is a characteristic of type 2 diabetes mellitus (T2DM),1 accompanied by abnormality in the temporal patterns of circulating insulin concentration.2–4 The circulating insulin concentration changes over the course of 24 h, including a persistently low level during fasting and a surge in response to food ingestion, consisting of basal and additional secretions from the pancreas, respectively.5,6