Chapter 20: Integrated Pathophysiologic Concepts: Insulin and the Pancreas & Diabetes Mellitus

Flashcards covering insulin, pancreas function, types of diabetes, diagnostic criteria, treatment goals, gestational diabetes, acute and chronic complications.

What are the endocrine and exocrine functions of the pancreas?

Endocrine: produces insulin and glucagon from the Islets of Langerhans. Exocrine: secretes alkaline fluids and digestive enzymes.

Which cells in the Islets of Langerhans secrete insulin and glucagon?

Beta cells secrete insulin; Alpha cells secrete glucagon (delta cells relate to other hormones like somatostatin).

What are the metabolic roles of insulin in the body?

Promotes glucose absorption into liver, muscle, and adipose tissue; facilitates transport of potassium, phosphate, and magnesium into cells; promotes lipid storage and protein synthesis.

What regulates insulin release from the pancreas?

Insulin levels rise with increases in blood glucose, amino acids, potassium, phosphate, magnesium, glucagon, and gastrin; fall with low blood glucose, high insulin levels, and stimulation of alpha cells.

What is diabetes mellitus?

A condition characterized by the body's inability to regulate glucose, resulting in inadequate metabolism of macronutrients.

How many main types of diabetes mellitus are described, and what are they?

Type 1, Type 2, and Gestational diabetes.

What causes Type 1 diabetes and what are its key features?

Immunodestruction of pancreatic beta cells leading to a significant or total insulin deficiency; multifactorial influences; about 10% of cases; hyperglycemia, hyperketonemia, and ketoacidosis.

What are the classic clinical manifestations of Type 1 diabetes?

Polydipsia, polyuria, polyphagia, nocturia, fatigue, weight loss, and blurred vision.

What diagnostic thresholds are listed for fasting and random blood glucose in diabetes?

Fasting >126 mg/dL; Random >200 mg/dL.

What HbA1c criterion is listed for diabetes in these notes?

HbA1c ≥ 8%.

What are the treatment goals and components for glycemic control in Type 1 diabetes?

Glycemic control with a target fasting glucose of 70–120 mg/dL; self-monitoring of blood glucose; carbohydrate management; regular exercise; insulin replacement therapy (rapid/short-, intermediate-, or long-acting).

What is Type 2 diabetes characterized by pathophysiologically?

Insulin resistance with reduced adequate insulin secretion; influenced by genetic and environmental factors; obesity is a major risk factor.

What are the major risk factors for Type 2 diabetes besides obesity?

Being over 30 years old, having a family history, and being of Native American, Hispanic, or African American descent.

What are common clinical manifestations of Type 2 diabetes?

Often asymptomatic; possible symptoms include visual changes, kidney function changes, coronary artery disease, peripheral vascular disease, recurrent infections, and neuropathy.

What are the diagnostic criteria for Type 2 diabetes?

Fasting glucose >126 mg/dL; Random glucose >200 mg/dL; consider pre-diabetes 110–125 mg/dL; tests to differentiate from Type 1 and assess long-term complications.

What are the main treatment approaches for Type 2 diabetes?

Weight control; diet and exercise; oral glycemic agents; insulin replacement therapy; goal to maintain optimal blood glucose levels.

What is gestational diabetes and its significance?

Glucose intolerance that appears during pregnancy; typically temporary but increases risk of developing Type 2 diabetes later; affects up to 15% of pregnancies.

How is gestational diabetes managed, and what are potential fetal risks if untreated?

Dietary changes, exercise, and possibly insulin; risks include fetal macrosomia, neonatal hypoglycemia, hypocalcemia, and birth defects.

What are the acute complications of diabetes mellitus?

Hypoglycemia; Diabetic Ketoacidosis (DKA); Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNK); Somogyi effect; dawn phenomenon.

What causes hypoglycemia in diabetes management?

Excessive insulin dosage, inadequate food intake, vomiting, strenuous exercise, or infection.

What does DKA stand for and what is HHNK?

DKA = Diabetic Ketoacidosis; HHNK = Hyperglycemic Hyperosmolar Nonketotic Syndrome (nonketotic hyperglycemia).

What are the microvascular complications of diabetes?

Retinopathy and nephropathy.

What are the macrovascular and neuropathic complications of diabetes?

Macrovascular: diseases of the coronary arteries, cerebrovascular system, and peripheral arteries; Neuropathies: nerve degeneration with numbness, tingling, weakness, pain, and muscle wasting.

What is the relationship between gestational diabetes and future diabetes risk?

Gestational diabetes increases the risk of developing Type 2 diabetes later in life.

What is the expected frequency of infection as a chronic complication of diabetes?

Increased susceptibility to infections.