Final answer:
Insulin and insulin secretagogues promote glucose uptake, increased fat storage, and protein synthesis, which can lead to weight gain. Insulin-like growth factors induced by insulin also contribute to body growth. Insulin resistance requires higher levels of insulin, often resulting in further weight gain.
Step-by-step explanation:
Why Insulins and Insulin Secretagogues Are Associated with Weight Gain
Insulins and insulin secretagogues are prescribed as treatments for diabetes mellitus to manage blood glucose levels effectively. Upon administration of these medications, insulin facilitates the uptake of glucose from the bloodstream by skeletal muscle cells and adipose cells, which can lead to weight gain. The hormone insulin does not just lower blood glucose levels, but it also has several anabolic effects like promoting triglyceride and protein synthesis and stimulating the liver to convert excess glucose into glycogen for storage. These actions contribute to the accumulation of fat and an increase in body weight.
Furthermore, insulin induces the production of insulin-like growth factors (IGF), which stimulate body growth and a higher metabolic rate. Conversely, in the presence of insulin resistance, which is frequently seen in conditions such as type 2 diabetes and polycystic ovary syndrome (PCOS), higher levels of insulin are required to manage blood glucose levels, which may further contribute to weight gain. Insulin secretagogues stimulate the secretion of insulin from the pancreas, similarly enhancing the body's ability to store energy and leading to weight gain.
Finally, insulin also reduces blood glucose levels by stimulating glycolysis and inhibiting enzymes involved in glycogenolysis and gluconeogenesis. However, with insulin resistance, type 2 diabetes, or PCOS, this careful regulation of blood glucose is disturbed. As a consequence, more insulin or medications that stimulate insulin secretion are needed to maintain normal blood glucose levels, which can result in increased weight.