Diabetes Mellitus Overview

Diabetes Mellitus Definition

• A disturbance of carbohydrate metabolism caused by insulin deficiency, resistance, or both, resulting in hyperglycemia and glucosuria, with secondary disturbances in protein and fat metabolism.
• Affects about 1-2% of the population.

Diabetes Mellitus Types

• Type 1 (IDDM): Insulin-dependent diabetes mellitus, previously termed juvenile-onset diabetes.
  • Characterized by insulin deficiency due to damage of beta cells.
• Type 2 (NIDDM): Non insulin-dependent diabetes mellitus, previously termed maturity-onset diabetes.
  • May involve insulin resistance, abnormal insulin structure, or both.
  • Combined with relatively reduced insulin secretion that may become absolute in some cases.

Theories of Type 2 Diabetes Etiology

• Central Obesity: Fat concentrated around the waist, impacting abdominal organs, linked to insulin resistance.
• Adipokines: Hormones secreted by abdominal fat that potentially impair glucose tolerance.
• Family History: Predisposition to type 2 diabetes in individuals with close relatives who have the condition.

Comparing Type 1 and Type 2 Diabetes

• Incidence: Type 1 accounts for 10% of cases while Type 2 represents 90%.
• Age of Onset: Type 1 typically develops before 30 years of age (usually between 12-14), while Type 2 occurs after 40 years of age.
• Sex: Type 1 is more common in males, while Type 2 is more prevalent in females.
• Body Weight: Individuals with Type 1 are usually underweight, whereas Type 2 patients are commonly overweight.
• Severity: Type 1 is generally more severe than Type 2.
• Stability: Type 1 diabetes is often unstable and referred to as "brittle diabetes". Type 2 is generally more stable.
• Insulin Requirement: Insulin is essential for Type 1, while it is usually not needed in the early stages of Type 2.
• Oral Hypoglycemic Effectiveness: Oral hypoglycemic agents are ineffective in Type 1, but they can be effective in the initial stages of Type 2.

Symptoms of Diabetes Mellitus

• Asymptomatic: Can go unnoticed and be discovered accidentally.
• Classic Symptoms:
  • Polyuria (increased urination)
  • Polydipsia (increased thirst)
  • Polyphagia (increased hunger, with weight loss especially in Type 1)
  • Pruritis (itchiness, particularly in the vulva and anal region)
  • Parathesia (tingling or numbness)
  • Premature loosening of teeth
  • Repeated infections (e.g., boils)
• Complications: Long-term complications related to diabetes.
• Diabetic Coma: A serious consequence of uncontrolled diabetes.

Diabetes Mellitus Investigations

• Plasma Glucose: Measures fasting and 2-hour postprandial glucose levels and includes an oral glucose tolerance test (OGTT).
  • Normal Levels: Fasting (less than 100 mg%), 2-hour postprandial (less than 140 mg%).
  • Impaired Glucose Tolerance (IGT): Fasting (greater than or equal to 100 mg% but less than 126 mg%), 2-hour postprandial (greater than or equal to 140 mg% but less than 200 mg%).
  • Overt Diabetes: Fasting (greater than or equal to 126 mg%), 2-hour postprandial (greater than or equal to 200 mg%). Symptoms of diabetes plus a causal plasma glucose concentration of greater than or equal to 200 mg/dl.
• Glycosylated Hemoglobin (HA1c): Measures the level of glucose bound to hemoglobin in red blood cells.
  • Used to assess diabetic control over the preceding 8-12 weeks.
  • Normal level is 6% of total hemoglobin.
• Urine Analysis:
  • Tests for glucose using strips and less frequently, solutions like Benedict's reagent.
  • Tests for ketone bodies using strips and Rother's sodium nitroprusside test.

Monitoring Diabetes Treatment

• Home Blood Glucose Monitoring (HBGM): Regular self-monitoring of blood glucose levels.
• Urine Testing: Testing urine for glucose.

Diabetes Mellitus Management

• Patient Education: Critical component, providing information on diabetes and its management.
• Dietetic Support: Tailored dietary recommendations for managing blood glucose levels.
• Sensible Exercise: Regular physical activity is encouraged to improve insulin sensitivity.
• Self-Monitoring: Regular blood glucose level testing to monitor treatment effectiveness.

Type 1 Diabetes Treatment

• Insulin Therapy: Primary treatment, involving artificial insulin delivered via injections.
• Blood Glucose Monitoring: Regular testing to monitor blood glucose levels.
• Insulin Types:
  • Regular Insulin: Rapid-acting insulin.
  • NPH Insulin: Intermediate-acting insulin.
  • Insulin Analogs: Synthetic insulin analogs like Humalog and Novolog (rapid-acting) and Lantus/Levemir (long-acting).
• Insulin Pump: Option for delivering insulin continuously, allowing for more flexibility and control.
• Blood Lancet: Tool used to draw blood for blood glucose testing.

Type 2 Diabetes Treatment

• Lifestyle Modifications: Initial steps prioritizing:
  • Increased Physical Activity: Regular exercise to enhance insulin sensitivity.
  • Decreased Carbohydrate Intake: Reduced carbohydrate intake for optimal blood glucose management.
  • Weight Loss: Weight loss can improve insulin sensitivity, even with modest reductions.
• Oral Antidiabetic Drugs: Used when lifestyle modifications are insufficient.
  • Improve insulin production and management of blood glucose levels.
• Insulin Therapy: May become necessary as beta cell function deteriorates.
  • Typically used for type 2 patients not responding to oral medications or those with longstanding diabetes.

Additional Considerations for Diabetes Management

• Cardiovascular Disease Management: Increased risk for cardiovascular disease in patients with diabetes.
  • Encourage:
    • Controlling blood pressure
    • Lowering cholesterol
    • Exercising regularly
    • Quitting smoking
    • Consuming a heart-healthy diet
    • Wearing diabetic socks and shoes.
• Oral Hypoglycemic Agents: Medications that help lower blood glucose levels.
• Insulin Therapy: Provides exogenous insulin to replace or supplement the body's own insulin production.

Acute Complications of Diabetes

• Diabetic Ketoacidosis (DKA):
  • Life-threatening complication, often associated with high blood glucose levels.
  • Marked by low insulin levels, leading the liver to turn to fat for fuel (ketosis), producing ketone bodies.
  • Ketone buildup leads to metabolic acidosis.
  • Characterized by dehydration, rapid and deep breathing, and abdominal pain.
  • Can cause hypotension, shock, renal failure, brain edema, and death.
  • More common in type 1 diabetes.
• Hyperosmolar Hyperglycemic State (HHS):
  • Different from DKA but shares some symptoms.
  • Occurs when very high blood glucose levels (often above 300 mg/dl) draw water out of cells into the blood.
  • The kidneys then excrete excess glucose in urine, leading to dehydration and increased blood osmolarity.
  • Requires urgent medical treatment, usually starting with fluid volume replacement.
  • Lethargy can progress to coma, more common in type 2 diabetes than type 1.
• Hypoglycemia:
  • Abnormally low blood glucose levels (below 70 mg/dl).
  • Can cause:
    • Agitation
    • Sweating
    • Symptoms of sympathetic nervous system activation
    • Altered consciousness
    • Coma
    • Seizures
    • Brain damage
    • Death
  • May result from:
    • Excessive or incorrectly timed insulin
    • Excessive or incorrectly timed exercise
    • Insufficient food intake
  • Treatment involves:
    • Sugary drinks or food
    • Glucagon injection in severe cases.