<s>[INST] What is glycated hemoglobin (HbA1c)?  [/INST] Glucose binds to a specific part of hemoglobin and HbA1c (Hemoglobin A1c), glycated hemoglobin is formed. Initially, the reaction between glucose and hemoglobin is reversible (labile HbA1c), but ultimately an irreversible and stable HbA1c is formed. The average life span of red blood cells is 2-3 months. HbA1c reflects the average blood sugar control for the past two to three months.

For a given HbA1c level, the preceding 30 days contribute substantially more (50%) to the HbA1c level, than glucose levels 90-120 days earlier (10%). It does not take 120 days to detect a clinically meaningful change. ~94% of total hemoglobin is non-glycated while ~6% is glycated, ~5% of glycated hemoglobin is HbA1c.  Source: HEMOCUE. Link: https://www.hemocue.com/en/health-areas/diabetes/what-is-diabetes-faq. Field: Endocrine. Disease: Diabetes </s>