Box 2: Commonly encountered sources of artifacts in measurements of blood glucose
Measurement methodReason for falsely low blood glucoseReason for falsely elevated glucose
Capillary glucose

  • Decreased circulation (2) (hypotension, Raynaud phenomenon, peripheral vascular disease)

  • Analytical errors (3) (high hematocrit, high oxygen levels [> 100 mm Hg], test strip expiry)

  • Operator error (3)

  • Sugary substances on skin (3)

  • Low hematocrit (3)

  • Icodextrin-containing peritoneal dialysis solutions (3)*

  • High uric acid levels (3)*

  • Low oxygen levels (3)

Venous glucose

  • Leukocytosis (1), (2) (leukemia, (2) reactive leukocytosis (4))

  • Reticulocytosis (1), (2) (polycythemia vera, (2), (5) chronic hemolytic anemia (6))

  • Prolonged delay in transport or analysis (1)

  • Hyperviscosity (2)

Subcutaneous glucose monitor

  • Local compression (7)

  • Presence of salicylic acid (8)

  • First 12 h of new sensor (8)

  • Acetaminophen (9)*

  • Hydroxyurea (9)

  • Vitamin C (8)

  • ↵* Method dependent.