Which factor does NOT affect insulin absorption?

Insulin absorption can be impacted by several physiological and environmental factors. Among the options provided, time of day is the factor that generally does not have a direct influence on how insulin is absorbed into the bloodstream.

Injection site is significant because different areas of the body (e.g., abdomen, thigh, or arm) can absorb insulin at different rates; for instance, abdominal injections typically allow for faster absorption than those into the thigh. Temperature also plays a role; insulin is absorbed more quickly when injected into warmer body areas due to increased blood flow, while colder locations can slow this process. Physical activity affects insulin absorption as well; exercise can enhance blood flow to the muscles, leading to faster absorption when insulin is injected into areas that are active.

Since time of day does not alter the pharmacokinetics of insulin, it is the correct choice in this context. Insulin absorption is more influenced by physical and environmental conditions rather than the specific timing of the insulin administration.