Association between blood glucose variability and coronary plaque instability in patients with acute coronary syndromes

Abstract

Background: Blood glucose variability is receiving considerable attention as a new risk factor for coronary artery disease. This study aimed to investigate the association between blood glucose variability and coronary plaque tissue characteristics.

Methods: In 57 patients with acute coronary syndrome, integrated backscatter intravascular ultrasound (IB-IVUS) and gray-scale IVUS were performed before balloon dilatation or stent implantation in the culprit vessels. Standard IVUS indices were evaluated for volume index (volume/length), and plaque components were measured by IB-IVUS for percent tissue volume. In addition to conventional glucose indicators, blood glucose variability in a stable state was determined by calculating the mean amplitude of glycemic excursions (MAGE) using a continuous glucose monitoring system.

Results: Higher MAGE values were significantly correlated with larger percent plaque volumes (r = 0.32, p = 0.015), and increased lipid (r = 0.44, p = 0.0006) and decreased fibrous (r = -0.45, p = 0.0005) plaque components. In contrast, HbA1c or fasting plasma glucose values were not significantly correlated with plaque volumes and percent plaque components. Homeostasis model assessment of insulin resistance values were positively correlated with vessel (r = 0.35, p = 0.007) and plaque (r = 0.27, p = 0.046) volumes, but not with percent plaque components. In multiple regression analysis, higher MAGE values were independently associated with increased lipid (β = 0.80, p = 0.0035) and decreased fibrous (β = -0.79, p = 0.0034) contents in coronary plaques.

Conclusions: Among all glucose indicators studied, only higher blood glucose variability was an independent determinant of increased lipid and decreased fibrous contents with larger plaque burden, suggesting blood glucose variability as one of the important factors related to coronary plaque vulnerability.

Fig. 1

Representative case of CGMS monitoring. Patient was a 59-year-old man who was diagnosed with STEMI. He had medical history of hypertension, hyperlipidemia and current smoking, and was diagnosed with impaired glucose tolerance on OGTT during hospital admission. Conventional glucose indicators were within normal range: however, CGMS monitoring revealed sustained postprandial hyperglycemia that was more prominent toward the evening meal, and significant hypoglycemia at night. MBG mean blood glucose, FPG fasting plasma glucose

Fig. 2

Correlations between glucose variability and IVUS indices

Fig. 3

Correlations between hemoglobin A1c and IVUS indices

Fig. 4

Correlations between fasting plasma glucose and IVUS indices

Fig. 5

Correlations between HOMA-IR and IVUS indices