Insulin Resistance Explained! What Is Insulin Resistance & How It Leads To Type II Diabetes?

Summary

Insulin, a vital peptide hormone, is secreted by pancreatic beta cells to regulate carbohydrate, fat, and protein metabolism. It lowers blood glucose by facilitating glucose uptake into cells and promoting glycogen storage while inhibiting fat breakdown. Insulin resistance, characterized by reduced cell responsiveness, leads to impaired glucose uptake and can result in hyperglycemia and type 2 diabetes. Factors contributing to insulin resistance include obesity, sedentary lifestyle, diet, genetics, and certain medications. This condition is also linked to metabolic syndrome, cardiovascular disease, and non-alcoholic fatty liver disease.

Takeaways

• 💉 Insulin is a peptide hormone produced by the beta cells of the pancreas, essential for regulating metabolism.
• 🍽 Insulin secretion is triggered by high blood glucose levels, especially after eating.
• 🏃‍♂️ Insulin helps glucose enter cells, particularly muscles and adipose tissue, to lower blood sugar.
• 💊 It promotes the storage of glucose as glycogen in the liver and muscle cells for energy reserve.
• 🚫 Insulin inhibits the breakdown of fat by suppressing lipase, the enzyme for fat degradation.
• 🍲 It stimulates the synthesis of fatty acids in the liver, contributing to fat storage.
• 🥚 Insulin also enhances the uptake of amino acids and promotes protein synthesis in tissues.
• 🚫 Insulin resistance is when cells become less responsive to insulin, impairing glucose uptake.
• 📈 Factors like obesity, sedentary lifestyle, high intake of refined carbs, and family history predispose individuals to insulin resistance.
• 🔍 Mechanisms behind insulin resistance include receptor downregulation, signaling defects, and mitochondrial dysfunction.
• 💉 Compensatory hyperinsulinemia occurs when the pancreas tries to overcome resistance by secreting more insulin.
• 🚑 Persistent insulin resistance can lead to type 2 diabetes and is associated with metabolic syndrome and cardiovascular disease.

Q & A

What is insulin and where is it produced?

Insulin is a peptide hormone produced by the beta cells of the pancreatic islets, which plays a crucial role in regulating carbohydrate, fat, and protein metabolism in the body.

How is insulin secretion triggered?

Insulin secretion is triggered by elevated blood glucose levels, typically after meals.

What does insulin do in terms of glucose uptake into cells?

Insulin facilitates the uptake of glucose into cells, particularly muscle and adipose cells, thereby lowering blood glucose levels.

How does insulin promote glucose storage in the body?

Insulin promotes the storage of glucose as glycogen in the liver and muscle cells.

What is the role of insulin in fat metabolism?

Insulin inhibits the breakdown of fat in adipose tissue by inhibiting lipase, an enzyme responsible for fat degradation, and promotes the synthesis of fatty acids in the liver.

How does insulin affect protein synthesis in tissues?

Insulin stimulates the uptake of amino acids and promotes protein synthesis in tissues.

What is insulin resistance and what are its consequences?

Insulin resistance is a pathological condition where cells become less responsive to insulin, leading to impaired glucose uptake, increased blood glucose levels, and various metabolic disturbances.

What factors predispose an individual to insulin resistance?

Factors predisposed to insulin resistance include obesity, particularly central obesity, sedentary lifestyle, high intake of refined carbohydrates, sugars, and saturated fats, family history of diabetes or insulin resistance, advancing age, and certain medications such as glucocorticoids.

How do the factors contributing to insulin resistance affect the body?

These factors contribute to insulin resistance through mechanisms such as insulin receptor down regulation, receptor mutations, postreceptor signaling defects, ectopic fat accumulation, elevated free fatty acid levels in blood, mitochondrial dysfunction, and inflammation.

What is compensatory hyperinsulinemia and how is it related to insulin resistance?

Compensatory hyperinsulinemia is a condition where the pancreas secretes more insulin than usual in response to insulin resistance, leading to high insulin levels.

What are the potential outcomes of persistent insulin resistance and hyperinsulinemia?

Persistent insulin resistance coupled with hyperinsulinemia and pancreatic beta cell dysfunction can ultimately result in the development of type 2 diabetes.

How is insulin resistance associated with other health conditions?

Insulin resistance is strongly associated with metabolic syndrome, cardiovascular disease, and non-alcoholic fatty liver disease.