The influence of shorter red blood cell lifespan on the rate of HbA1c target achieved in type 2 diabetes patients with a HbA1c detection value lower than 7%

BACKGROUND: Variations in the red blood cell (RBC) lifespan can affect glycosylated hemoglobin (HbA1c) test values, but there is still a lack of evidence regarding how and to what degree the RBC lifespan influences HbA1c in the type 2 diabetes mellitus (T2DM) population owing to the restriction of traditional RBC lifespan–detection means. This study aimed to investigate the influence of RBC lifespan variation on HbA1c values in T2DM patients with a HbA1c detection value lower than 7%. METHODS: Patients with HbA1c <7% were divided into two groups: RBC lifespan <90 days and RBC lifespan ≥90 days. We collected blood glucose levels at seven time points for three consecutive months, assessed the HbA1c and glycosylated albumin levels, and calculated the hemoglobin glycation index (HGI) for each patient. RESULTS: There were no statistical differences in the HbA1c value between two groups, but the estimated glycosylated hemoglobin (eHbA1c) was significantly higher in patients with an RBC lifespan <90 days. The proportion of the eHbA1c ≥7% in the group with an RBC lifespan <90 days was significantly higher than the other group (33.87% vs. 12.50%, p < .01). Pearson analysis showed a significant negative correlation between RBC lifespan and the HGI in patients with T2DM (r = −0.348, p < .01). CONCLUSION: A reduced RBC lifespan in T2DM patients caused a noticeable underestimate of the blood glucose levels as presented by HbA1c detection value.