Which of the following are complications of insulin therapy? (Select all that apply).

Choice A rationale: Lipodystrophy is a complication of insulin therapy where changes in subcutaneous fat tissue occur at injection sites. Repeated injections in the same area can lead to either lipohypertrophy (a lump of fat) or lipoatrophy (a depression in the skin), which can impair insulin absorption. Rotating injection sites helps prevent this condition. Choice B rationale: The dawn phenomenon is a physiological event, not a complication of insulin therapy. It is a morning hyperglycemia caused by the normal nocturnal release of counter-regulatory hormones like growth hormone and cortisol, which increase liver glucose production and cause blood sugar levels to rise. This is an endogenous process. Choice C rationale: Hypoglycemia is a common and serious complication of insulin therapy. It occurs when insulin levels are too high relative to the available glucose, causing blood sugar to drop below 70 mg/dL. This can result from a missed meal, excessive exercise, or an incorrect insulin dose, leading to neuroglycopenic symptoms. Choice D rationale: The Somogyi phenomenon, or rebound hyperglycemia, is a physiological response to insulin-induced hypoglycemia. An excessive insulin dose causes blood glucose to drop during the night, triggering the release of counter-regulatory hormones that cause rebound hyperglycemia in the morning. This is not a direct complication of the insulin itself but of its administration. Choice E rationale: Insulin resistance is a complication where the body's cells become less responsive to the effects of insulin, requiring higher and higher doses to achieve the desired glycemic control. This can be caused by various factors, including obesity, inactivity, and the development of antibodies to insulin, impairing its ability to facilitate glucose uptake.