Diabetes Overview and Types

Diabetes Definition

• A group of metabolic diseases characterized by the inability to produce sufficient amounts of insulin or the inability to respond to insulin properly.

Alpha vs Beta Cell Function

• Alpha Cells: When blood sugar is low, alpha cells release glucagon, signaling the liver to release stored glucose, raising blood sugar.
• Beta Cells: When blood sugar is high, beta cells release insulin, helping body cells absorb glucose, lowering blood sugar. Beta cells are often found in clusters called islets of Langerhans.

Type 1 vs Type 2 vs Gestational Diabetes

Type 1

• Pathophysiology: Immune attack on beta cells, preventing insulin production.
• Prevalence: "Juvenile onset"
• Characteristics: Insulin-dependent, beta cell destruction, autoimmune disease (or idiopathic).

Type 2

• Pathophysiology: Increased blood glucose and insulin, eventually leading to insulin resistance.
• Prevalence: 90-95 percent of diabetics, adult onset.
• Characteristics: Insulin resistance, insulin secretion defect, strong genetic influence.

Gestational Diabetes

• Pathophysiology: Glucose intolerance during pregnancy.
• Characteristics: Occurs in 2-10% of pregnancies, increases future risk of type 2 diabetes for the mother, and possibly the child.

Criteria for Testing Diabetes

• Fasting Plasma Glucose: ADA/CDC: 5.6-6.9 mmol/L (100-125 mg/dL); WHO: 6.1-6.9 mmol/L (110-125 mg/dL); Diabetes: 7.0 mmol/L (≥126 mg/dL)
• 2-Hour Plasma Glucose: 2.2-11.1 mmol/L (140-200 mg/dL); ≥ 11.1 mmol/L (≥200 mg/dL)
• HbA1c: 5.7-6.4% (39-47 mmol/mol); ≥6.5% (≥48 mmol/mol)

Hyperglycemia vs Hypoglycemia

• Hyperglycemia: Fasting blood glucose >130 mg/dL. Kidneys excrete glucose and water. Can lead to Diabetic Ketoacidosis (body metabolizes fat, producing ketones). Leads to organ damage.
• Hypoglycemia: Fasting blood glucose <70 mg/dL. Too much insulin or too little carbohydrates. Can lead to coma and death.

Macrovascular vs Microvascular vs Neuropathy (Diabetes)

• Macrovascular: large vessel disease (coronary arteries, cerebrum, and periphery)
• Microvascular: small vessel disease (retinopathy, nephropathy)
• Neuropathy: effects peripheral and autonomic nervous systems. Includes peripheral nerve damage in lower extremities (loss of sensation, reflexes, and increased risk of infections) and autonomic neuropathy.

Diabetes- Medical History and Physical Exam

• Medical History: Focus on acute and chronic complications, laboratory values (HbA1c, plasma glucose), lipids, proteinuria, blood pressure, body weight, and body mass index.
• Physical Exam: Elevated resting heart rate; loss of sensation (especially lower extremities); loss of reflexes (especially lower extremities); foot sores/ulcers; excessive bruising; retinal vascular abnormalities

Diabetes Exercise Testing

• Special Considerations: Exercise testing needs to consider cardiovascular risk, neuropathy, blood glucose control.
• ECG Stress Testing: May be indicated in those with additional risk factors.
• Types of Exercise: Cardio-respiratory, Resistance, Range of Motion.

Obesity (Chapter 8)

• Definition: Abnormal or excessive fat accumulation that risks health.
• Calculation: BMI= weight (kg)/ height^2 (m^2) or weight (lb) x 703 / height^2 (in^2).
• Classification: Body weight-related categories (underweight, normal, overweight, and various obesity classes). Table 8.1 (in the text) provides specific criteria.
• Adipocytes: Primary cell type in adipose tissue, stores triglycerides.
• Adipokines: Adipose-derived hormones.
• Leptin: Hormone suppressing appetite, affecting metabolism.
• Adiponectin: Increases metabolism and energy expenditure.
• Ghrelin: Hormone stimulating hunger, released from gastrointestinal tract.

Obesity- Pathophysiology

• Risks: Diabetes, hypertension, dyslipidemia, breathlessness, sleep apnea, gall bladder disease, heart disease, osteoarthritis, hyperuricemia, complications during pregnancy, and cancer.
• Fat Distribution: Android fat (abdomen, upper body) often more associated with health risks than gynoid fat(hips, thighs, and buttocks).

Obesity - Exercise Testing

• Types of Diets: High-protein, low-carb, hypocaloric, time-restricted feeding.
• Pharmacological: Appetite suppressants, fat absorption reducers.
• Surgical: Significant weight loss, but carries risk of complications, potentially permanent weight gain.
• Exercise is important for maintaining and improving health at any body weight.

Hyperlipidemia and Dyslipidemia

• Lipids: Chylomicron, VLDL, IDL, LDL, HDL (in order of size and density), with different roles in transporting lipids & cholesterol.
• LDL receptor: Pathway that removes cholesterol from bloodstream.
• Reverse Cholesterol Pathway: Pathway that transports cholesterol back to the liver.

Metabolic Syndrome

• Definition: Collection of interrelated cardiometabolic risk factors (more common when in the presence of overweight/obesity).. Leading to greater risk of atherosclerotic cardiovascular disease.
• Exercise Recommendation: Moderate intensity cardio exercise 150-250 min per week. Resistance exercise can supplement cardio exercise.

Peripheral Artery Disease

• Definition: Blockage of leg arteries leading to decreased blood flow to the muscles.
• Classifications: Fontaine (asymptomatic, mild-severe claudication, rest pain, ulceration, gangrene); Rutherford (based on tissue loss).
• Clinical Considerations: Inclaudication is the most common symptom.
• Exercise Considerations: Exercise testing and special considerations for PAD will need to consider the presence, severity, and stage of claudication.
• Important Considerations Duration, intensity, use of Borg 15 category scale or similar scales.

Asthma

• Pathophysiology: Airway inflammation and airflow limitation.
• Diagnosis: Spirometry measurement such as FEV₁/FVC, flow volume loop.
• Special Considerations: Exercise testing needs to use and monitor BP, ECG, arterial oxygen saturation, dyspnea (Borg scale).
• Exercise Prescription: Walking, running, swimming, or other aerobic exercise (at intensity just below the anaerobic threshold). Exercise precautions.

Cancer (Chapter 21)

• Definition: Uncontrolled cell growth.
• Types of cancer: Carcinoma, sarcoma, leukemia, lymphoma.
• Differentiation: Benign (slow-growing, isolated) and malignant (faster-growing, invasive).
• Pathophysiology: Tumor growth, angiogenesis, metastasis.
• Treatment Options: Surgery, radiation, chemotherapy, biotherapy
• Exercise Testing: Special considerations for both cancer types and related conditions.

This quiz covers the definitions, cell functions, and differences between Type 1, Type 2, and Gestational diabetes. It examines the underlying pathophysiology and characteristics of each type, providing a comprehensive overview of diabetes. Test your understanding of these metabolic diseases and their clinical implications.