Diabetes Mellitus Overview

Diabetes Mellitus Overview

• Chronic condition characterized by insufficient insulin production from the pancreas.
• Results in hyperglycemia, which is a high level of glucose in the blood.
• Hypoglycemia indicates low blood sugar levels.

Type 1 Diabetes Mellitus (DM)

• Also known as insulin-dependent, juvenile, or childhood onset diabetes.
• Usually diagnosed around 9 years of age; symptoms include thirst and weight loss.
• Represents 0-15% of the total population.
• Involves destruction of beta cells in the pancreas that produce insulin, leading to lack of glucose entry into cells.
• Ketones are produced as a last energy source due to beta cell destruction.

Immune Response in Type 1 DM

• Autoantibodies target and destroy insulin-producing beta cells.
• Presence of ketonuria indicates fat metabolism resulting from low insulin.

Type 2 Diabetes Mellitus (DM)

• Characterized by insulin resistance; glucose is present but not effectively used by the body.
• No ketonuria typically observed.
• Often develops in adults and is linked to obesity, genetic factors, lack of exercise, and conditions like PCOS.
• Represents about 80% of the diabetic population.
• Beta cells may be present but their function declines, potentially leading to kidney failure if untreated.

Pathophysiology of DM

• Both type 1 and type 2 diabetes result in hyperglycemia.
• Untreated type 2 diabetes can lead to non-ketotic hyperosmolar state and dehydration due to excessive glucose production.

Symptoms and Diagnostic Criteria

• Common symptoms include:
  • Polydipsia (increased thirst)
  • Polyphagia (increased hunger)
  • Polyuria (increased urination)
• Diagnostic tests include:
  • HbA1c (glycosylated hemoglobin), which monitors long-term glucose levels.
  • Fasting blood sugar, Oral Glucose Tolerance Test (OGTT), and random plasma glucose levels.

Pre-Diabetes Indicators

• Acanthosis nigricans (darkening of skin) can signal pre-diabetes.
• Individuals over 45 years old should be tested for diabetes every 3-6 months.

Gestational Diabetes Mellitus (GDM)

• Glucose intolerance occurring during pregnancy.
• Diagnosed using OGTT; caused by metabolic hormonal changes associated with pregnancy.
• Risks for babies include being overweight, hypoglycemia, and jaundice.
• Mothers may face premature births and increased risk for type 2 diabetes post-pregnancy.

Specific Causes of Diabetes Mellitus

• Genetic defects such as Maturity Onset Diabetes of the Young (MODY) have a strong familial correlation.
• Other causes include diseases affecting the exocrine pancreas and endocrinopathies like Cushing's disease.
• Drug or chemical induced DM often involves hypoglycemic episodes.

Blood Sugar Monitoring and Testing Protocol

• Fasting periods vary: typically 8-10 hours for blood tests.
• Capillary blood glucose > 140 mg/dl indicates potential diabetes.
• OGTT involves drinking glucola and testing blood within a set timeframe after consumption.

Diagnostic Methods for Diabetes

• Various enzymatic and oxidation methods are used for glucose measurement, including:
  • Glucose oxidase
  • Hexokinase (gold standard)
• HbA1c testing requires EDTA-venous whole blood; its formation is proportional to plasma glucose levels.
• High-Pressure Liquid Chromatography (HPLC) is the gold standard for HbA1c detection.

Testing Parameters and Ranges

• Fast Blood Sugar (FBS) levels < 126 mg/dl indicate normal.
• OGTT < 200 mg/dl and random plasma glucose < 200 mg/dl are considered normal.
• HbA1c levels:
  • Normal: 4.2-6.2%
  • Pre-diabetes: 5.7-6.4%
  • Diabetes: > 6.5%
• Fructosamine normal range is 205-285 mm/l.

Ketone Testing

• Ketone bodies indicate fat metabolism during energy deficiency.
• Tests for acetoacetate and β-hydroxybutyrate utilize fresh serum or urine samples.

Observable Signs of Hypoglycemia

• Symptoms manifest when blood glucose levels drop to 50-55 mg/dl; treatment may require rapid glucose administration.