Integrated Pathophysiologic Concepts: Diabetes Mellitus

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Questions and Answers

What is the primary source of energy for all tissue cells?

Glucose (correct)

Proteins

Fatty acids

Amino acids

Where is stored glucose primarily located?

In the heart

In the liver and muscles (correct)

In the blood

In the lungs

Which of the following hormones is responsible for increasing blood glucose levels?

Somatostatin

Gastrin

Glucagon (correct)

Insulin

What role does insulin play in glucose metabolism?

Facilitates glucose entry into cells Signup and view all the answers

When does insulin increase in the bloodstream?

When potassium levels rise Signup and view all the answers

What is the action of insulin on lipid metabolism?

Increases triglyceride storage Signup and view all the answers

What effect does high blood glucose have on insulin secretion?

Stimulates insulin production Signup and view all the answers

Which type of cells in the pancreas produce insulin?

Beta cells Signup and view all the answers

What is the primary function of insulin in the body related to glucose?

To allow glucose to move into cells Signup and view all the answers

What diagnostic level of fasting blood sugar indicates diabetes mellitus?

126 mg/dL Signup and view all the answers

Which of the following reflects a condition where insulin is present but cells do not respond to it?

Type 2 Diabetes Signup and view all the answers

Which test is considered the gold standard for diagnosing diabetes and monitoring control?

HgA1C test Signup and view all the answers

What is the significance of an HgA1C level of 6.5 or higher?

Diagnostic for diabetes Signup and view all the answers

What are common symptoms associated with hyperglycemia in diabetes?

Polydipsia, polyuria, and polyphagia Signup and view all the answers

In Type 1 Diabetes, what happens to the beta cells?

They are destroyed Signup and view all the answers

What causes the high levels of glucose in the blood for individuals with Type 1 Diabetes?

Destruction of insulin-producing cells Signup and view all the answers

What leads to the production of ketones in Type 1 Diabetes?

Insufficient glucose in cells Signup and view all the answers

Which of the following is a classic sign of diabetic ketoacidosis (DKA)?

Kussmaul respirations Signup and view all the answers

What is a key indicator of diabetic ketoacidosis (DKA)?

Presence of ketones in urine Signup and view all the answers

In the context of Type 1 Diabetes, what triggers an increased demand for insulin?

Pregnancy or infection Signup and view all the answers

What is the primary treatment focus for diabetic ketoacidosis?

Correct acidosis and normalize glucose levels Signup and view all the answers

Why is carbohydrate counting essential for individuals with Type 1 Diabetes?

To determine the amount of insulin to administer Signup and view all the answers

What complication can result from insufficient insulin in Type 1 diabetes?

Diabetic ketoacidosis Signup and view all the answers

Which of the following symptoms is NOT one of the classic three polys associated with Type 1 Diabetes?

Polycythemia Signup and view all the answers

What is the primary function of a continuous glucose monitor (CGM)?

To track blood glucose levels Signup and view all the answers

Which of the following is a common clinical manifestation of Type 2 Diabetes?

Polyphagia Signup and view all the answers

What complication is most commonly associated with extreme hyperglycemia in Type 2 Diabetes?

Hyperosmolar Hyperglycemia Non Ketototic Syndrome (HHNK) Signup and view all the answers

Which method is NOT mentioned as a treatment approach for Type 2 Diabetes?

Hormone replacement therapy Signup and view all the answers

What does an insulin infusion pump primarily do?

Delivers small doses of insulin throughout the day Signup and view all the answers

What causes the hyperosmolarity related to Hyperosmolar Hyperglycemia Non Ketototic Syndrome (HHNK)?

Deficiency of insulin Signup and view all the answers

Which symptom is associated with low fluid levels in diabetic patients experiencing HHNK?

Dehydration Signup and view all the answers

How does exercise affect insulin sensitivity in individuals with Type 2 Diabetes?

Decreases insulin resistance Signup and view all the answers

What is a common factor contributing to the gradual onset of Type 2 Diabetes?

Insulin resistance Signup and view all the answers

How does a CGM communicate blood glucose levels to users?

Wirelessly to a smartphone or insulin pump Signup and view all the answers

Study Notes

Chapter 20: Integrated Pathophysiologic Concepts: Diabetes Mellitus

Diabetes mellitus is a disease where the body's ability to produce or respond to insulin is impaired, leading to abnormal carbohydrate metabolism and elevated blood/urine glucose levels.
Glucose is the primary energy source for all cells. Insulin facilitates glucose uptake into cells.

Glucose Metabolism Review

Glucose is used by cells for energy production.
Stored glucose is called glycogen.
Glycogen is stored primarily in the liver and muscles.
Hormones involved in glucose metabolism include insulin and glucagon.
Insulin promotes glucose uptake by cells, promoting protein synthesis and fat storage, and also potassium, phosphate, and magnesium transport into cells.
Glucagon, on the other hand, breaks down glycogen in the liver to raise blood glucose.

Pancreas Review

The pancreas has both endocrine and exocrine functions.
Endocrine function: produces hormones like insulin and glucagon.
Exocrine function: secretes digestive enzymes and bicarbonate-rich fluids.
Islets of Langerhans are clusters of cells in the pancreas, including alpha cells (produce glucagon), beta cells (produce insulin), and delta cells (produce somatostatin).

Function of Insulin

Insulin is an anabolic hormone promoting glucose uptake into cells, protein synthesis, and lipid storage (preventing fat breakdown).
Insulin binds to insulin receptors on cells, opening glucose channels to let glucose enter cells.
Insulin also facilitates the transport of potassium, phosphate, and magnesium into cells.

Feedback Mechanisms—Glucose Homeostasis

Insulin secretion increases in response to elevated blood glucose, amino acids, potassium, phosphate, magnesium, glucagon, and gastrin.
Insulin decreases when blood glucose is low, insulin levels are high, or alpha cell function is stimulated (resulting in glucagon production).
Glucagon is released when glucose levels are low, causing the breakdown of glycogen in the liver to raise blood glucose.

Diabetes Mellitus Types

Type 1 Diabetes: Characterized by the destruction of beta cells in the pancreas, leading to a lack of insulin production. This is often an autoimmune response; often presenting in childhood or young adulthood.
Type 2 Diabetes: Characterized by insulin resistance, where the body does not respond effectively to insulin, and/or a decline in insulin production. It is usually a gradual onset condition, sometimes presenting in younger age groups now, and increasing in prevalence.
Gestational Diabetes: A form of diabetes that develops during pregnancy due to the body's impaired response to insulin.

Diabetes Mellitus Type 1 Pathophysiology

Beta cells are destroyed.
Insulin production is reduced or absent.
This leads to elevated blood and insulin levels, eventually leading to pancreatic exhaustion.

Diabetes Mellitus Type 2 Pathophysiology

Insulin resistance, where cells don't respond properly to insulin, decreases glucose uptake.
Decreased insulin production by beta cells.
Increased glucose production by the liver.
These factors lead to elevated blood glucose.

Diabetes Mellitus Type II Diagnosis

Fasting blood sugar (FBS) greater than 126 mg/dL.
Random blood sugar (RBS) greater than 200 mg/dL.
Hemoglobin A1c (HbA1c) is a gold standard blood test; indicates average blood glucose levels over several months (typically three months, due to the lifespan of Red Blood Cells).
- An A1C of 6.5% or greater is diagnosed as diabetes.
- Values between 5.7%-6.4% indicate prediabetes.

Clinical Manifestations of Diabetes Mellitus

Polydipsia: excessive thirst (caused by osmotic diuresis, trying to get rid of excess sugar in the blood via urine).
Polyuria: excessive urination (caused by osmotic diuresis).
Polyphagia: excessive hunger (caused by cells unable to access glucose).
Glycosuria: sugar in the urine.
Unintentional weight loss (when glucose isn't accessible, the body breaks down protein and fats for energy).

Type 1 Diabetes Complications

Diabetic ketoacidosis (DKA): A serious complication characterized by ketone accumulation in the blood due to insufficient insulin and an increased rate of fat breakdown, leading to acidosis.
- Symptoms include fruity breath (ketones), Kussmaul respirations (deep and rapid breathing to compensate for acidosis), dehydration, and possibly coma.

Type 1 Diabetes Treatment

Daily insulin injections are needed because insulin is not produced naturally, often with various types of insulin (rapid acting, short acting, intermediate acting).
Careful carbohydrate counting is critical to determine the correct insulin dosage based on the amount of carbohydrates consumed.
Regular exercise is very important and critical in diabetes management.

Insulin Pumps and CGMs

Insulin pumps deliver insulin continuously, improving blood glucose control.
Continuous glucose monitors (CGMs) measure glucose levels continuously and signal insulin pumps to adjust insulin delivery.

Diabetes Type 2 Treatment Approaches

Medications improve insulin sensitivity, insulin secretion, and glucose excretion to maintain optimal blood glucose levels.
Diet and exercise are important components in managing type 2 diabetes.

Hypoglycemia

Abnormally low blood sugar (<70 mg/dL).
Symptoms include light-headedness, palpitations, excessive perspiration, and (more severely) confusion, trembling, seizures, and coma.
Treatment involves quickly raising blood glucose with quick-acting carbohydrates.

Insulin Shock

A rapid onset of hypoglycemia often due to excessive insulin or insufficient carbohydrate intake.
Symptoms: diaphoresis, light-headedness, tremor, confusion; can progress to coma.
Treated with quick-acting glucose.

How Hyperglycemia Damages Blood Vessels

Hyperglycemia leads to vessel wall thickening, damage, inflammation, and plaque buildup (atherosclerosis), affecting vessels throughout the body. This reduces blood flow, leading to tissue damage.

Diabetic Macrovascular Complications

Increased risk of cardiovascular issues, stroke, peripheral artery disease, leading to foot complications, and heart attack.
Cardiovascular issues, including clogged arteries, stroke high blood pressures, increase in risk of heart attack and other issues stemming form poor blood flow.

Diabetic Microvascular Complications

Retinopathy (eye damage, blindness).
Nephropathy (kidney damage, kidney failure).
Neuropathy (nerve damage, numbness, tingling, pain, possible muscle wasting).

Chronic Complications Summary

Diabetes can cause a range of chronic complications, including various types of neuropathy, retinopathy, nephropathy and atherosclerosis.

Wound Healing in Diabetes

Poor wound healing in patients with diabetes is linked to elevated glucose levels, which impair the blood supply and nerve function vital to healing. These factors can also lead to bacterial infection, further delaying or impeding healing.

Gestational Diabetes

Happens only during pregnancy, caused by insulin resistance.
Often leads to larger babies.
Routine prenatal glucose tolerance tests (GTTs) are critical for diagnosis and monitoring.
Usually resolves after delivery, but carries increased risk of developing Type 2 DM later in life.
Prevention involves balanced nutrition (protein, carbs, and fats).

Somogyi Effect

Temporary overcompensation by the body; Hypoglycemia during the night is corrected during the morning, leading to a rebound of hyperglycemia.

Dawn Phenomenon

The natural hormone secretion of the body (such as GH, cortisol, glucagon, catecholamines) that occurs in the early morning hours result in an increase of blood glucose levels, especially in the pre-dawn hours, leading to higher levels of blood glucose in the morning.

Miscellaneous: Orthostatic Hypotension

A sudden drop in blood pressure when standing up due to insufficient compensatory mechanisms to maintain blood pressure.
Causes include autonomic issues, insufficient norepinephrine response, poor blood pressure response.

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Description

Explore the essential concepts of diabetes mellitus, including its effects on glucose metabolism and the role of insulin and glucagon. This quiz covers key physiological aspects, the function of the pancreas, and how these elements contribute to the management of diabetes. Test your understanding of how glucose and hormones interact in the body.