What Causes Variability in Insulin Action?
Several factors give rise to insulin variability (Table 2). 5,7 Any factor that affects the delivery of insulin to or absorption of insulin from the subcutaneous tissue can affect the variability of insulin action. For example, variations in administration technique, including changes in the depth or site of injection, amount of subcutaneous blood flow, time lapse before needle withdrawal, and quality of the suspension (when crystallized insulins are used) all affect the predictability and intensity of insulin activity. 7 Table 2: Causes of Intraindividual Variability in Insulin Action5,7 • Factors related to the insulin preparation/dose: • Physicochemical properties of the insulin preparation • Insulin concentration • Insulin dose • Factors depending on the injection conditions: • Depth of injection • Anatomical site of injection • Delay before withdrawing the needle • Blood flow in the subcutaneous tissue • Factors related to the individual: • Hypoglycemic effect • Physical activity
