Understanding Diabetes

Type 1 Diabetes

How Blood Glucose and Insulin Work:

  • Eating carbohydrates raises blood glucose levels, providing energy to the body. The ideal blood glucose range is between 4.4–6.1 mmol/L.
  • Insulin, a hormone produced by the pancreas, lowers blood sugar levels by helping the body absorb and use glucose as fuel.
  • Insulin works in two primary ways:
    1. It signals cells to absorb glucose from the blood for energy.
    2. It helps store glucose in the liver and muscles as glycogen for future use.

Without insulin, glucose cannot enter the cells, leading to high blood sugar levels.

Role of Glucagon:

  • Glucagon, another hormone produced by the pancreas, raises blood sugar levels when they drop too low.
  • It signals the liver to break down glycogen into glucose and convert proteins and fats into glucose, ensuring energy availability.

Together, insulin and glucagon maintain blood sugar balance.

Ketogenesis and Ketoacidosis:

  • Ketogenesis occurs when the body lacks glucose or glycogen, such as during fasting. The liver converts fatty acids into ketones, which can fuel the brain and other organs.
  • In healthy individuals, ketones are harmless. However, in Type 1 diabetes, lack of insulin can lead to ketoacidosis (dangerously high ketone levels), causing:
    • Acetone-like breath odor.
    • Severe dehydration from excess urination (polyuria) and intense thirst (polydipsia).
    • Acidic blood due to depleted bicarbonate levels, leading to metabolic acidosis.

Causes of Type 1 Diabetes:

  • The pancreas stops producing insulin, often triggered by genetic factors or viral infections.
  • Without insulin, the body initiates ketogenesis, leading to a dangerous cycle of hyperglycemia, ketosis, and acidosis.

Complications:

  • Hyperglycemia overwhelms the kidneys, resulting in glucose in the urine and dehydration.
  • Insulin deficiency disrupts potassium regulation, causing potential electrolyte imbalances during treatment.

Type 2 Diabetes

How It Develops:

  • Overexposure to glucose and insulin makes cells resistant to insulin’s effects.
  • To compensate, the pancreas produces more insulin, eventually leading to pancreatic exhaustion and decreased insulin production.
  • This results in chronic hyperglycemia.

Screening and Diagnosis:

  • The HbA1C test measures the average blood sugar over three months.
    • Hemoglobin A1C forms when glucose attaches to hemoglobin in red blood cells. High glucose levels result in more glycated hemoglobin.
    • A1C is a key indicator of blood sugar stability, as red blood cells live approximately 120 days.

Pre-Diabetes

What It Means:

  • Pre-diabetes signals increasing insulin resistance and reduced ability to regulate blood glucose effectively.

Prevention:

  • While not yet diabetic, individuals can prevent progression to Type 2 diabetes through lifestyle changes such as:
    • Adopting a healthier diet.
    • Increasing physical activity.
    • Managing weight.

Diagnostic Markers:

  • Impaired fasting glucose: The body struggles to lower blood sugar levels after a period of not eating carbohydrates.
  • Impaired glucose tolerance: The body cannot efficiently process glucose after consuming a carbohydrate-rich meal.

Diagnostic Ranges:

  • Pre-diabetes:
    • HbA1c: 42–47 mmol/mol
    • Fasting glucose: 6.1–6.9 mmol/L
    • Glucose tolerance test: 7.8–11.1 mmol/L
  • Diabetes:
    • HbA1c: ≥48 mmol/mol
    • Random glucose: >11 mmol/L
    • Fasting glucose: >7 mmol/L
    • Glucose tolerance test: >11 mmol/L