DM

Question 1

What are the three main factors contributing to hyperglycemia in diabetes mellitus?

Answer 1

Decreased insulin secretion, decreased glucose utilization, increased glucose production.

Question 2

What is the renal threshold for glucose, beyond which glucosuria occurs?

Answer 2

180 mg/dL.

Question 3

What is the mechanism behind polyuria in diabetes mellitus?

Answer 3

Glucosuria attracts water in the renal tubules, leading to excessive urination.

Question 4

Which metabolic pathways are utilized for energy when glucose cannot be used effectively?

Answer 4

First fats, then proteins.

Question 5

What is the primary regulator of glucose homeostasis?

Answer 5

Insulin.

Question 6

What are the two main metabolic pathways insulin promotes?

Answer 6

Glycogen synthesis and lipogenesis.

Question 7

What are the two main hormones that regulate glucose levels in the fasting state?

Answer 7

Insulin and glucagon.

Question 8

What is the function of C-peptide in assessing insulin secretion?

Answer 8

It is a marker of endogenous insulin production and helps differentiate endogenous vs. exogenous insulin sources.

Question 9

What is the rate-limiting step of glucose-regulated insulin secretion?

Answer 9

Glucose phosphorylation by glucokinase.

Question 10

What is the earliest detectable abnormality in both type 1 and type 2 diabetes?

Answer 10

Impaired first-phase insulin response.

Question 11

Which hormones are classified as incretins and what is their role?

Answer 11

GLP-1 and GIP; they stimulate insulin secretion and suppress glucagon secretion in a glucose-dependent manner.

Question 12

How does insulin resistance affect hepatic glucose production?

Answer 12

It prevents insulin from suppressing gluconeogenesis, leading to fasting hyperglycemia.

Question 13

What is the pathophysiologic role of islet amyloid polypeptide (amylin) in type 2 diabetes?

Answer 13

It forms amyloid deposits in pancreatic islets, contributing to beta cell dysfunction.

Question 14

What is the primary genetic susceptibility factor for type 1 diabetes?

Answer 14

HLA region on chromosome 6.

Question 15

How does obesity contribute to insulin resistance?

Answer 15

Through increased free fatty acids, pro-inflammatory cytokines, and ectopic lipid accumulation in muscle and liver.

Question 16

What is the honeymoon phase in type 1 diabetes?

Answer 16

A transient period of improved glycemic control following initial insulin therapy due to residual beta cell function.

Question 17

What is the key distinguishing characteristic of type 1 diabetes compared to type 2 diabetes?

Answer 17

Type 1 diabetes is autoimmune-mediated and leads to absolute insulin deficiency.

Question 18

What is the mechanism by which metformin lowers blood glucose?

Answer 18

It decreases hepatic glucose production and increases insulin sensitivity.

Question 19

Why are sulfonylureas contraindicated in patients with severe renal impairment?

Answer 19

They are metabolized in the liver and excreted by the kidneys, increasing the risk of hypoglycemia.

Question 20

Which diabetes medication class can cause weight loss and has cardiovascular benefits?

Answer 20

GLP-1 receptor agonists (e.g., liraglutide, semaglutide).

Question 21

What is the major side effect of SGLT2 inhibitors?

Answer 21

Increased risk of urinary tract infections and diabetic ketoacidosis.

Question 22

How does exercise affect glucose metabolism in diabetes?

Answer 22

It increases glucose uptake in muscle independent of insulin and improves insulin sensitivity.

Question 23

Why should insulin doses be reduced before exercise in type 1 diabetes?

Answer 23

To prevent exercise-induced hypoglycemia due to increased glucose uptake by muscles.

Question 24

What are the three stages of type 1 diabetes progression?

Answer 24

Stage 1: Presence of two or more autoantibodies, normal glucose; Stage 2: Dysglycemia; Stage 3: Clinical diabetes.

Question 25

What are the hallmark symptoms of diabetes mellitus?

Answer 25

Polyuria, polydipsia, polyphagia, and unexplained weight loss.

Question 26

What is the gold standard for diagnosing diabetes mellitus?

Answer 26

Fasting plasma glucose ≥126 mg/dL, 2-hour OGTT ≥200 mg/dL, random glucose ≥200 mg/dL with symptoms, or HbA1c ≥6.5%.

Question 27

What is the preferred first-line treatment for type 2 diabetes?

Answer 27

Metformin, unless contraindicated.

Question 28

What is a significant risk factor for gestational diabetes mellitus (GDM)?

Answer 28

A history of macrosomia (baby >4 kg) or previous GDM.

Question 29

Which diabetes complication is characterized by albuminuria and declining GFR?

Answer 29

Diabetic nephropathy.

Question 30

What is the most common cause of death in diabetes patients?

Answer 30

Cardiovascular disease.

Question 31

Which diabetic complication presents with burning pain and numbness in the feet?

Answer 31

Diabetic peripheral neuropathy.

Question 32

What is the primary mechanism behind diabetic retinopathy?

Answer 32

Chronic hyperglycemia leading to microvascular damage and neovascularization.

Question 33

Why is tight glycemic control not always recommended for elderly patients with diabetes?

Answer 33

Due to increased risk of hypoglycemia and cardiovascular events.

Question 34

What are the major risk factors for developing type 2 diabetes?

Answer 34

Obesity, sedentary lifestyle, family history, and metabolic syndrome.

Question 35

How does diabetic ketoacidosis (DKA) differ from hyperosmolar hyperglycemic state (HHS)?

Answer 35

DKA has ketonemia and metabolic acidosis, while HHS has severe hyperglycemia and dehydration without significant ketosis.

Question 36

What is the mainstay treatment for diabetic ketoacidosis?

Answer 36

Intravenous fluids, insulin infusion, and electrolyte correction.

Question 37

Which class of medications should be avoided in diabetic patients with heart failure?

Answer 37

Thiazolidinediones (e.g., pioglitazone, rosiglitazone) due to fluid retention.

Question 38

How does chronic hyperglycemia contribute to microvascular complications?

Answer 38

By causing oxidative stress, advanced glycation end-product formation, and endothelial dysfunction.

Question 39

What is the target HbA1c for most patients with diabetes?

Answer 39

<7%, though individualized based on patient factors.

Question 40

What are the three main factors contributing to hyperglycemia in diabetes mellitus?

Answer 40

Decreased insulin secretion, decreased glucose utilization, increased glucose production.

Question 41

Which autoantibodies are commonly associated with type 1 diabetes?

Answer 41

GAD65, IA-2, insulin autoantibodies, and ZnT8.

Question 42

What is the effect of chronic hyperglycemia on endothelial cells?

Answer 42

It leads to oxidative stress, inflammation, and vascular damage.

Question 43

Why do patients with diabetes have an increased risk of infections?

Answer 43

Impaired neutrophil function, poor circulation, and hyperglycemia impair immune response.

Question 44

Which biochemical marker is useful in distinguishing type 1 from type 2 diabetes?

Answer 44

C-peptide (low in type 1, normal or high in type 2).

Question 45

What is the Somogyi effect in diabetes management?

Answer 45

Rebound hyperglycemia following nocturnal hypoglycemia due to counterregulatory hormone activation.

Question 46

How does the Dawn phenomenon differ from the Somogyi effect?

Answer 46

Dawn phenomenon is due to early morning cortisol and GH release, leading to increased fasting glucose.

Question 47

Which form of diabetes is associated with mutations in hepatocyte nuclear factor genes?

Answer 47

Maturity-onset diabetes of the young (MODY).

Question 48

Why is HbA1c an unreliable measure in patients with hemolytic anemia?

Answer 48

Shortened red blood cell lifespan leads to falsely low HbA1c values.

Question 49

Which enzyme deficiency is associated with neonatal diabetes?

Answer 49

Glucokinase deficiency.

Question 50

What is the primary defect in gestational diabetes?

Answer 50

Increased insulin resistance due to placental hormones.

Question 51

Which cytokines contribute to beta-cell destruction in type 1 diabetes?

Answer 51

TNF-α, IL-1, and IFN-γ.

Question 52

How does SGLT2 inhibition increase the risk of euglycemic diabetic ketoacidosis?

Answer 52

By increasing glucagon secretion and reducing insulin levels, promoting ketogenesis.

Question 53

What is the main characteristic of lipodystrophy-associated diabetes?

Answer 53

Severe insulin resistance due to loss of adipose tissue and leptin deficiency.

Question 54

Which diabetes-related complication is associated with Charcot foot?

Answer 54

Diabetic neuropathy leading to joint destruction and deformity.

Question 55

What is LADA (latent autoimmune diabetes in adults)?

Answer 55

A slow-progressing form of autoimmune diabetes with features of both type 1 and type 2 diabetes.

Question 56

What is the mechanism behind nonalcoholic fatty liver disease (NAFLD) in diabetes?

Answer 56

Insulin resistance leads to increased hepatic lipid accumulation and inflammation.

Question 57

What is the significance of postprandial hyperglycemia in diabetes?

Answer 57

It is a major contributor to cardiovascular complications and oxidative stress.

Question 58

Why do patients with diabetes develop gastroparesis?

Answer 58

Autonomic neuropathy impairs gastric motility, delaying gastric emptying.

Question 59

Which antihypertensive medications are preferred in diabetic patients with nephropathy?

Answer 59

ACE inhibitors or ARBs to reduce proteinuria and protect renal function.

Question 60

How does glucotoxicity contribute to beta-cell dysfunction?

Answer 60

Chronic hyperglycemia impairs insulin secretion and promotes apoptosis of beta cells.

Question 61

Why does hyperglycemia lead to polyphagia?

Answer 61

Due to cellular starvation from lack of effective glucose uptake.

Question 62

What are Kimmelstiel-Wilson nodules and what do they indicate?

Answer 62

Hyaline deposits in glomeruli, characteristic of diabetic nephropathy.

Question 63

Which neurotransmitter is involved in the regulation of pancreatic beta-cell function?

Answer 63

Acetylcholine.

Question 64

What is the primary mechanism of action of thiazolidinediones?

Answer 64

Activation of PPAR-γ to improve insulin sensitivity.

Question 65

What is the significance of insulin receptor autoantibodies?

Answer 65

They can cause type B insulin resistance, leading to severe hyperglycemia or hypoglycemia.

Question 66

Which hormones contribute to insulin resistance during pregnancy?

Answer 66

Human placental lactogen (hPL), estrogen, and progesterone.

Question 67

What is the role of leptin in diabetes and metabolism?

Answer 67

It regulates appetite and energy balance; deficiency or resistance can lead to obesity and diabetes.

Question 68

How does exercise improve insulin sensitivity in type 2 diabetes?

Answer 68

By increasing GLUT4 translocation to muscle cell membranes for glucose uptake.

Question 69

Which medication class is contraindicated in patients with a history of medullary thyroid carcinoma?

Answer 69

GLP-1 receptor agonists due to the risk of C-cell hyperplasia.

Question 70

What is the mechanism of beta-cell apoptosis in type 2 diabetes?

Answer 70

Endoplasmic reticulum stress, oxidative stress, and lipotoxicity.

Question 71

Which biochemical pathway is responsible for the formation of advanced glycation end-products (AGEs)?

Answer 71

The polyol pathway.

Question 72

What is the function of islet amyloid polypeptide (amylin) in glucose regulation?

Answer 72

It slows gastric emptying and suppresses glucagon secretion.

Question 73

Which class of diabetes medications increases the risk of fractures?

Answer 73

Thiazolidinediones (TZDs) due to effects on bone metabolism.

Question 74

Why is fasting insulin measurement useful in evaluating insulin resistance?

Answer 74

Elevated fasting insulin suggests compensatory hyperinsulinemia due to resistance.

Question 75

What is the role of fibroblast growth factor 21 (FGF21) in metabolism?

Answer 75

It enhances insulin sensitivity and regulates lipid metabolism.

Question 76

Why do diabetic patients have an increased risk of cardiovascular disease?

Answer 76

Endothelial dysfunction, chronic inflammation, and atherogenic dyslipidemia.

Question 77

What is the primary mechanism by which bariatric surgery improves glycemic control?

Answer 77

Increased GLP-1 secretion and enhanced insulin sensitivity.

Question 78

Which molecular mechanism links hyperglycemia to diabetic neuropathy?

Answer 78

Increased activation of the polyol pathway leading to oxidative stress and nerve damage.

Question 79

Why does diabetes increase the risk of non-alcoholic steatohepatitis (NASH)?

Answer 79

Insulin resistance promotes hepatic fat accumulation and inflammation.