Diabetes Pathophysiology

Question 1

Type 1

Answer 1

• Autoimmune destruction of pancreatic beta cells
• Impairment of insulin secretion (absolute deficiency of insulin)
• Children, young adults

Question 2

Type 2

Answer 2

• Obesity is a major contributing factor
• Impairment of insulin secretion and defects in insulin action (relative insulin deficiency)
• Adults, increasing in children

Question 3

Complications of Diabetes

Answer 3

Retinopathy
Neuropathy
Amputation
Nephropathy
Cardiovascular complications

Question 4

Absorptive State

Answer 4

• Ingested glucose supplies immediate energy needs of the body and builds body energy stores
• Glucose is taken up by liver, pancreas, muscle, adipose tissue

Question 5

Glucose from diet gets stored as

Answer 5

Glycogen

Question 6

Free fatty acids from fat in diet get stored as

Answer 6

Triglycerides

Question 7

Amino acids get stored as

Answer 7

Protein

Question 8

Insulin stimulates what in the liver

Answer 8

Glycogen synthesis

Fatty acid synthesis

Question 9

Insulin inhibits what in the liver

Answer 9

Glycogenolysis
Gluconeogenesis
Ketogenesis

Question 10

Insulin stimulates what in fat

Answer 10

Glucose uptake

Triglyceride synthesis and storage

Question 11

Insulin inhibits what in fat

Answer 11

Lipolysis

Question 12

Insulin stimulates what in muscle

Answer 12

Glucose uptake
Glycogen synthesis
Amino acid uptake
Protein synthesis

Question 13

Insulin inhibits what in muscle

Answer 13

Protein breakdown

Question 14

Glucagon

Answer 14

Glucose provider

released in response to low plasma glucose concentrations

Question 15

Glucagon increases

Answer 15

Glycogenolysis
Gluconeogenesis
Plasma glucose concentration
Fat breakdown
Protein breakdown

Question 16

What goes wrong in diabetes

Answer 16

Increased blood glucose levels are a result of

• insufficient insulin secretion
• Resistance to the action of insulin
• Inadequate suppression of post-meal glucagon
  - Body still releases glucagon instead of inhibiting glucagon

Question 17

Symptoms of Type 2 Diabetes

Answer 17

Polyuria
Polydipsia
Unexplained weight loss
Fatigue
Recurrent infections

Question 18

FPG Diabetes

Answer 18

> /= 126 mg/dL

Question 19

FPG prediabetes

Answer 19

100-125 mg/dL

Question 20

FPG normal

Answer 20

less than 100 mg/dL

Question 21

Tolerance Test diabetes

Answer 21

> /= 200 mg/dL

Question 22

Tolerance Test prediabetes

Answer 22

140-199 mg/dL

Question 23

Tolerance Test normal

Answer 23

less than 140 mg/dL

Question 24

A1c diabetes

Answer 24

> /= 6.5%

Question 25

A1c prediabetes

Answer 25

5.7-6.4%

Question 26

A1c normal

Answer 26

less than 5.7%

Question 27

Categories of Increased Risk for Diabetes (prediabetes)

Answer 27

1. Elevated glucose that does not meet the classification for diabetes, but is still too high to be considered normal. 2. Impaired Fasting Glucose (100-125) 3. Impaired Glucose Tolerance (140-199) 4. A1c 5.7-6.4% * These categories confer an increased risk of progressing to diabetes and CVD in the future (30-50% will convert)

Question 28

Type 1 diabetes

Answer 28

Absolute deficiency of insulin secretion 5-10% of all diabetes cases Develops around 10-14 years, typically childhood/early adulthood Immune mediated is most common form -Autoimmune destruction of pancreatic beta cells

Question 29

Symptoms of Type 1 diabetes

Answer 29

``` Polyuria Polydipsia Weight loss Polyphagia Fatigue Ketoacidosis ```

Question 30

Risk Factors for T2D-Modifiable

Answer 30

``` Overweight/obesity Physical inactivity IFG/IGT HTN >140/90 HDL = 35 mg/dL Triglycerides >/= 250 mg/dL ```

Question 31

Risk factors for T2D-Nonmodifiable

Answer 31

``` Family history Race/ethnicity History of gestational diabetes Delivery of a baby > 9 lbs Poycycstic ovary syndrome ```

Question 32

Mechanisms of insulin resistance | Pre-receptor defects

Answer 32

Abnormal insulin molecule (mutations) | Anti-insulin antibodies

Question 33

Mechanisms of insulin resistance | Receptor defects

Answer 33

Decreased number of receptors | Reduction in receptor's binding affinity to insulin

Question 34

Mechanisms of insulin resistance | Post-binding defects

Answer 34

Defective insulin signal transduction | Defects in GLUT4 translocation

Question 35

Consequences of insulin resistance in muscle

Answer 35

Impaired glucose uptake and glycogen synthesis

Question 36

Consequences of insulin resistance in fat

Answer 36

Impaired glucose uptake Increased lipolysis Increased flux of free fatty acids to liver (dyslipidemia)

Question 37

Consequences of insulin resistance in liver

Answer 37

Increased glucose output Alterations in lipoprotein metabolism -Increased VLDL and triglycerides -Leads to increased hepatic glucose production

Question 38

Compensatory hyperinsulinemia

Answer 38

Pancreas secretes more insulin in an effort to overcome insulin resistance and maintain glucose homeostasis (helps for a short time)

Question 39

Post-prandial hyperglycemia

Answer 39

Loss of first phase insulin secretion Diminished glucose uptake in peripheral tissues Failure to suppress glucagon after a meal

Question 40

Fasting Hyperglycemia

Answer 40

Increased hepatic glucose production | Hepatic glucose output exceeds glucose uptake

Question 41

Amylin

Answer 41

Hormone co secreted with insulin from the pancreatic beta cells Involved in glucose regulation Slows rate of gastric emptying Suppresses postprandial release of glucagon Improves satiety signals