Association of Glycemic Variability With Early Vascular Dysfunction in Adults With Type 2 Diabetes
DOI:
https://doi.org/10.61336/jdme.0401.01Keywords:
Type 2 diabetes mellitus, glycemic variability, endothelial dysfunction, flow-mediated dilation, continuous glucose monitoring, vascular function, oxidative stressAbstract
Background: Glycemic variability represents fluctuations in blood glucose that are not fully captured by glycated hemoglobin (HbA1c). Increasing evidence suggests that repeated glucose excursions may contribute to vascular injury through oxidative stress, inflammation, and endothelial dysfunction. This study evaluated the association between glycemic variability and early vascular dysfunction in adults with type 2 diabetes mellitus (T2DM). Methods: A cross-sectional study was conducted among 180 adults with T2DM aged 35–70 years. Glycemic variability was assessed using 14-day continuous glucose monitoring. The coefficient of variation (CV), standard deviation (SD), mean amplitude of glycemic excursions (MAGE), and time in range (TIR) were calculated. Endothelial function was assessed by brachial artery flow-mediated dilation (FMD). Serum nitric oxide, endothelin-1, high-sensitivity C-reactive protein (hs-CRP), and fasting lipid parameters were also measured. Participants were categorized into lower- and higher-glycemic-variability groups according to the median glucose CV. Results: The mean age of participants was 54.2 ± 8.7 years, and 101 (56.1%) were male. Participants with higher glycemic variability had lower mean FMD than those with lower variability (5.1 ± 1.4% vs. 6.4 ± 1.6%, p < 0.001). Higher MAGE and glucose CV were associated with reduced FMD after adjustment for age, sex, diabetes duration, HbA1c, systolic blood pressure, body mass index, LDL cholesterol, and smoking status. Glucose CV showed an inverse correlation with FMD (r = −0.48, p < 0.001) and nitric oxide concentration (r = −0.35, p < 0.001), while positive correlations were observed with endothelin-1 and hs-CRP. Participants in the highest glucose-CV tertile had approximately 2.7-fold higher odds of impaired endothelial function compared with those in the lowest tertile. Conclusion: Higher glycemic variability was associated with markers of early vascular dysfunction in adults with T2DM, independently of average glycemic control. Assessment of glucose fluctuations may therefore provide additional information about vascular risk beyond HbA1c.
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