Which type of diabetes has impaired glucose induced secretion of insulin with preserved b cell mass?
**Core Concept**
Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder characterized by impaired insulin secretion and insulin resistance, leading to hyperglycemia. The pathophysiology involves impaired glucose-induced insulin secretion, but the pancreatic beta-cell mass is typically preserved initially.
**Why the Correct Answer is Right**
Impaired glucose-induced insulin secretion in T2DM is due to defective insulin signaling pathways in the beta-cells, leading to reduced insulin secretion in response to glucose. This is often associated with insulin resistance in peripheral tissues, further exacerbating hyperglycemia. The preserved beta-cell mass initially allows for some degree of insulin secretion, but eventually, beta-cell dysfunction and apoptosis occur, leading to a decline in insulin secretion.
**Why Each Wrong Option is Incorrect**
**Option A:** Type 1 diabetes mellitus (T1DM) is characterized by absolute insulin deficiency due to autoimmune destruction of pancreatic beta-cells, resulting in a complete loss of insulin secretion.
**Option B:** Maturity-onset diabetes of the young (MODY) is caused by genetic mutations affecting insulin secretion, but it is typically characterized by a preserved or even increased insulin secretion in response to glucose, not impaired.
**Option C:** Gestational diabetes mellitus (GDM) is a transient form of diabetes that develops during pregnancy, often due to insulin resistance and impaired insulin secretion, but it is not a chronic form of diabetes and does not typically involve preserved beta-cell mass.
**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between T2DM and T1DM, as T2DM is often managed with lifestyle modifications and oral hypoglycemic agents, whereas T1DM requires insulin replacement therapy.
**Correct Answer: C. Maturity-onset diabetes of the young (MODY) is characterized by impaired glucose induced secretion of insulin with preserved b cell mass.**