Diabetes Reference Ranges and Metabolism

Gestational Diabetes Reference Ranges

• Fasting glucose ≥ 92 mg/dL
• 1-hour glucose ≥ 180 mg/dL
• 2-hour glucose ≥ 153 mg/dL

Type 1 Diabetes Reference Ranges

• Fasting blood glucose > 126 mg/dL

Type 2 Diabetes Reference Ranges

• Fasting glucose ≥ 126 mg/dL
• Random glucose ≥ 200 mg/dL

Lactate Reference Range

• 0.5–2.2 mmol/L

Microalbumin Reference Range

• < 30 mg/24 hours in urine

Abnormal Metabolic Relationships in Insulin-Dependent Individuals

• Lack of insulin prevents glucose uptake
• Increased fatty acid oxidation and ketone production (acetoacetate, beta-hydroxybutyrate)
• Ketoacidosis can occur
• Impaired glucose metabolism leads to increased lactate due to anaerobic glycolysis

Causes of Hypoglycemia

• Insulin overuse
• Alcohol consumption
• Pancreatic islet cell tumors
• Fasting
• Postprandial hypoglycemia
• Medications

Detecting Ketones and Microalbumin

• Ketones in serum/urine are detected using nitroprusside tests (Acetest or Ketodiastix)
• Microalbumin in urine is measured by immunoassays or albumin-to-creatinine ratio

POCT Glucose Methods

• Portable meters utilize glucose oxidase or hexokinase methods
• Whole blood is used, resulting in 10-15% lower values compared to plasma or serum

Pros and Cons of Fructosamine Test

• Pros: Reflects short-term glucose control (2-3 weeks)
• Cons: Affected by protein metabolism disorders, less precise than HbA1c

Pyruvate and Lactate Relationship

• Pyruvate is converted to lactate under anaerobic conditions
• Increased lactate-to-pyruvate ratio (>35) suggests hypoxia
• Low ratio (<10) indicates mitochondrial dysfunction or pyruvate deficiency