Which conditions can cause falsely elevated HbA1c levels?

Which conditions can cause falsely elevated HbA1c levels?

• A. Hypertriglyceridemia, hyperbilirubinemia, iron deficiency anaemia, splenectomy
• B. Hyperglycemia and obesity
• C. Renal failure
• D. Vitamin B12 deficiency

Answer: (A)

HbA1c accuracy depends on how long red blood cells live and how the assay handles abnormal samples. When red cells survive longer, there’s more time for glucose to attach to hemoglobin, so HbA1c can appear higher even if average glucose isn’t elevated. Iron deficiency anemia prolongs red cell lifespan, and splenectomy reduces clearance of old red cells, both leading to a falsely higher HbA1c. Lipid and bilirubin abnormalities can interfere with some HbA1c assays, also yielding higher readings in certain methods. In contrast, true high glucose states like hyperglycemia and obesity raise HbA1c through actual increased glucose exposure, not a measurement artifact. Renal failure and vitamin B12 deficiency don’t consistently cause a false elevation in HbA1c.

HbA1c accuracy depends on how long red blood cells live and how the assay handles abnormal samples. When red cells survive longer, there’s more time for glucose to attach to hemoglobin, so HbA1c can appear higher even if average glucose isn’t elevated. Iron deficiency anemia prolongs red cell lifespan, and splenectomy reduces clearance of old red cells, both leading to a falsely higher HbA1c. Lipid and bilirubin abnormalities can interfere with some HbA1c assays, also yielding higher readings in certain methods. In contrast, true high glucose states like hyperglycemia and obesity raise HbA1c through actual increased glucose exposure, not a measurement artifact. Renal failure and vitamin B12 deficiency don’t consistently cause a false elevation in HbA1c.