The Effect of Alpha-Thalassemia on HbA1c Levels

Abstract

Background: Beta-thalassemia patients have shown that HbA1c levels are lower in patients and correlate with lower hemoglobin (Hb) levels. The findings are possibly due to the shortening of red blood cell lifespan and elevated fetal hemoglobin (Hb F) levels. Alpha-thalassemia is common in Southeast Asia. Patients with alpha-thalassemia also experience chronic hemolytic anemia that may affect HbA1c levels.

Objective: To investigate the effect of alpha-thalassemia on HbA1c levels and the correlation between Hb and HbA1c levels.

Methods: This cross-sectional study enrolled patients with alpha-thalassemia and a control group from September 2022 to April 2024 from the Tertiary care University Hospital. Thalassemia patients and control subjects were confirmed through hemoglobin typing (HPLC) and PCR for alpha-thalassemia. Inclusion criteria included individuals aged ≥ 15 years with confirmed non-diabetes mellitus status by fasting blood sugar (FBS) and hemoglobin A1c level (HbA1c). Exclusion criteria included anemia resulting from other hemoglobinopathies and anemia from other causes. An analysis of variance (ANOVA) test was employed for the statistical analysis, dependent on the distribution of data. Linear correlation analysis was employed to explore the association between anemia and HbA1c levels in the HbH disease group.

Results: A total of 158 patients were enrolled, comprising 56 control patients, 72 HbH disease patients, and 30 patients with alpha-thalassemia trait 1. Patient characteristics, including sex, fasting blood glucose, creatinine, and GFR, did not differ significantly between the groups. The mean ± SD of HbA1c compared between the control, alpha-thalassemia 1 trait, and HbH disease groups was 5.3% ± 0.4 mmol/mol, 5.3% ± 0.4 mmol/mol, and 4.1% ± 0.6 mmol/mol, respectively (P < 0.001). Significant differences in the mean HbA1c level ± SD [95% CI] were observed between the HbH disease and control groups (-1.25 ± 0.09 mmol/mol [95% CI -1.44 to -1.05] P < 0.001), whereas no significant difference was found in the alpha-thalassemia trait 1 group compared with the control group (0.06 ± 0.09 mmol/mol [95% CI -0.11 to 0.24] P= 0.476). Furthermore, no statistically significant linear correlation was observed between the degree of anemia and HbA1c levels in the HbH disease group.

Conclusion: In summary, HbH patients demonstrated notably lower HbA1c levels than the control group while levels were similar between the alpha-thalassemia trait 1 and control group.

No relevant conflicts of interest to declare.