Pancreatic Disease: Pancreatitis & Diabetes Mellitus

Class: Foundation Year

Course: Fundamentals of Human Biology

Code: IHD. 14

Lecturer & Date: Information not provided.

Learning Outcomes

• ALO 1: Review the biology of the pancreas and describe pancreatitis.

• ALO 2: Understand the difference between the three main types of diabetes.

• ALO 3: Describe the pathogenesis of Type 2 diabetes.

• ALO 4: Explain the main symptoms of Type 2 diabetes.

• ALO 5: Outline the steps in diagnosis and treatments of diabetes.

• ALO 6: Describe preventative approaches for type 2 diabetes.

Biology of the Pancreas

The pancreas has a long, flat structure located behind the stomach and is involved in both endocrine and exocrine functions.

Functions:

• Aids in digestion by producing digestive enzymes.

• Regulates blood sugar levels through hormone secretion.

Pancreatic Function

Exocrine Function

• Digestive Enzymes: Secreted into the duodenum via the main pancreatic duct. Includes:

  • Lipase: Digests fats by breaking them down into fatty acids and glycerol.

  • Amylase: Digests carbohydrates into simple sugars.

  • Proteases (e.g., trypsin, chymotrypsin): Digests proteins into peptides and amino acids.

Endocrine Function

• Produces and secretes hormones into the bloodstream specifically from the Islets of Langerhans:

  • Alpha Cells: Release glucagon, which raises blood sugar levels.

  • Beta Cells: Release insulin, which lowers blood sugar levels by facilitating cellular glucose uptake.

  • Delta Cells: Release somatostatin, which regulates the secretion of other hormones and slows down digestive processes.

Histology of the Pancreas

• The pancreas is surrounded by a thin connective tissue capsule with septae for structural support.

• Distinct lobules can be observed microscopically.

Islets of Langerhans include:

• Beta Cells: Crucial for insulin production and regulation of glucose levels in the body, thus playing an essential role in glucose metabolism.

Pancreatitis

Definition:

Inflammation of the pancreas which can be acute or chronic.

Symptoms:

• Can cause swelling, sharp abdominal pain, vomiting, and functional changes in the pancreas such as malabsorption of nutrients.

• Acute pancreatitis is often sudden and intense, while chronic pancreatitis leads to persistent abdominal pain and digestive issues.

Diabetes Mellitus Overview

General Info:

Diabetes occurs due to the inability to transport sugar (glucose) from the blood into cells, which leads to chronic hyperglycemia.

Types:

• Type 1 Diabetes (T1DM): Autoimmune destruction of beta cells, resulting in no insulin production and requiring lifelong insulin therapy.

• Type 2 Diabetes (T2DM): Characterized by insulin resistance followed by reduced insulin production; accounts for over 90% of diabetes cases. Often related to lifestyle factors such as obesity.

• Gestational Diabetes: Triggered by pregnancy-related hormone changes, increasing risks for Type 2 diabetes in later life.

Symptoms of Type 2 Diabetes

Symptoms may develop slowly and include:

• Discolored skin patches in the armpits or neck (acanthosis nigricans).

• Neuropathy characterized by pain or numbness in extremities (feet).

• Unlike Type 1 diabetes, Type 2 may not present with rapid symptoms such as weight loss or diabetic ketoacidosis.

Pathogenesis of Type 2 Diabetes

Involves:

• Impaired function and loss of islet beta-cells.

• Increased alpha-cell mass and inappropriate glucagon secretion which contribute to hyperglycemia.

• Changes at the cellular level negatively affect insulin release and action on glucose uptake by tissues.

Common Symptoms of Diabetes

Symptoms to monitor include:

• Polydipsia: Excessive thirst due to dehydration from urination.

• Polyphagia: Excessive hunger because cells are unable to utilize glucose properly.

• Polyuria: Frequent urination, leading to further dehydration.

• Additional Symptoms: Drowsiness or fatigue, skin issues including slow-healing sores, and blurred vision.

• Age of onset varies, with Type 1 typically presenting in youth and Type 2 in older adults, although increasingly noted in younger populations due to lifestyle changes.

Risk Factors for Type 2 Diabetes

Factors influencing risk include:

• Obesity: Excess body weight is the most significant risk factor.

• Sedentary Lifestyle: Lack of physical activity increases the risk.

• Poor Diet: High in processed foods, sugars, and fats.

• Family History: A child with a parent with T2DM has a 40% chance of developing diabetes, indicating a genetic connection.

Diagnosis and Treatments of Diabetes

Clinical Tests Include:

• Lipid Profile: Assessment for proteinuria & ketones which are elevated in T1DM.

• Blood Tests:

  • HbA1C: Measures the average blood glucose over the past 2-3 months.

  • Fasting Blood Sugar Test: Measures glucose levels after fasting.

  • Oral Glucose Tolerance Test (OGTT): Assesses the body's response to sugar.

  • Random Blood Sugar Test: Checks current blood sugar levels.

Medications for Type 2 Diabetes

Drug Classes and Examples:

• Biguanides (Metformin): Increases insulin sensitivity and decreases hepatic glucose production.

• Thiazolidinediones (e.g., Pioglitazone): Improve insulin sensitivity similarly.

• Sulfonylureas (e.g., Glipizide): Stimulate insulin secretion from beta cells.

• SGLT-2 Inhibitors (Dapagliflozin): Promote glucose excretion in urine leading to weight loss but may cause increased thirst.

• DPP-4 Inhibitors (Sitagliptin): Help modulate incretin hormones to improve glucose control.

• GLP-1 Mimetics (Exenatide): Help stimulate insulin secretion while inhibiting glucagon release.

Complications from Diabetes

Macrovascular Complications:

Consistently high blood sugar can lead to:

• Atherosclerosis: Increases risks of cardiovascular diseases, heart attacks, and strokes.

Microvascular Complications:

Chronically elevated blood sugar may damage small blood vessels leading to:

• Diabetic Retinopathy: Can result in vision loss.

• Diabetic Nephropathy: May lead to renal failure requiring dialysis.

• Diabetic Neuropathy: May result in foot ulcers, leading to severe complications and potential amputations.

Preventative Approaches for Type 2 Diabetes

• Diet: Increase intake of fiber-rich fruits, vegetables, and whole grains; reduce consumption of refined carbohydrates and sugars.

• Exercise: Aim for at least 150 minutes of moderate aerobic exercise weekly, with resistance training 2-3 times a week to improve insulin sensitivity.

• Monitoring: Regular HbA1C tests to assess control over blood glucose levels; daily blood sugar monitoring may be necessary depending on treatment strategies.

Conclusion

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