All of the following are associated with insulin resistance except –
**Core Concept**
Insulin resistance is a condition in which the body's cells become less responsive to insulin, a hormone produced by the pancreas that regulates blood glucose levels. This can lead to elevated blood sugar levels and is a key feature of type 2 diabetes. Insulin resistance is often associated with obesity, physical inactivity, and genetic predisposition.
**Why the Correct Answer is Right**
Insulin resistance is a complex condition influenced by multiple factors, including genetic mutations, environmental factors, and lifestyle choices. It is characterized by impaired glucose uptake in skeletal muscle, adipose tissue, and liver, leading to increased glucose production and impaired insulin signaling. Key molecular mechanisms involved in insulin resistance include decreased insulin receptor substrate-1 (IRS-1) activity, reduced phosphatidylinositol 3-kinase (PI3K) activity, and increased serine phosphorylation of IRS-1.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a known cause of insulin resistance. For example, obesity is characterized by chronic inflammation, oxidative stress, and adipokine dysregulation, all of which contribute to insulin resistance.
**Option B:** This option is incorrect because it is associated with insulin resistance. For instance, high-fat diets can lead to increased lipotoxicity, oxidative stress, and inflammation in skeletal muscle and adipose tissue, contributing to insulin resistance.
**Option C:** This option is incorrect because it is associated with insulin resistance. For example, physical inactivity is linked to reduced glucose uptake in skeletal muscle, decreased mitochondrial biogenesis, and impaired insulin signaling, all of which contribute to insulin resistance.
**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that insulin resistance is a common feature of metabolic syndrome, a cluster of conditions that increase the risk of developing type 2 diabetes and cardiovascular disease. These conditions include central obesity, hypertension, dyslipidemia, and elevated fasting glucose levels.
**Correct Answer:** D