HEMOGLOBIN A1C AND BODY MASS INDEX AS PREDICTORS OF DISCREPANCIES BETWEEN CONTINUOUS GLUCOSE MONITORING AND GLUCOMETER READINGS IN PREGNANT WOMEN WITH GESTATIONAL DIABETES

Abstract

This study investigated the relationship between differences in continuous glucose monitoring (CGM) and glucometer measurements and the clinical factors hemoglobin A1c (HbA1c) and body mass index (BMI) in women with gestational diabetes. We also evaluated if HbA1c and BMI could serve as predictors of CGM‑glucometer differences. Materials and methods: HbA1c was measured both continuously and categorically (≥5.9% vs <5.9%), and BMI was calculated in kg/m². An independent-samples t-test compared CGM differences between the two HbA1c categories. Pearson correlations examined relationships between CGM differences and HbA1c and BMI. A multiple linear regression assessed whether HbA1c and BMI predicted CGM differences. Results: Patients with elevated HbA1c (≥5.9%) had significantly higher CGM differences (M = 28.71, SD = 0.73) compared to those with lower HbA1c (M = 23.17, SD = 0.91), t(42) = -19.94, p < 0.001. CGM differences were very strongly correlated with HbA1c (r = .996, p < 0.001) and BMI (r = .984, p < 0.001). In the multiple regression model, only HbA1c significantly predicted CGM differences (B = 26.52, SE = 2.18, p < 0.001), whereas BMI was not statistically significant. The model explained 99.3% of the variance in CGM differences (R² = 0.993). Conclusions. The findings of our study suggest that HbA1c is strongly associated with CGM-glucometer differences, while BMI, despite a strong correlation, does not independently predict discrepancies when HbA1c is considered. These results underscore the importance of HbA1c in assessing CGM accuracy.