Coronary Flow Reserve and Glycemic Variability in Patients with Coronary Artery Disease

Abstract

Objective Glycemic variability is being increasingly recognized as an early indicator of glucose metabolic disorder and may contribute to the development of diabetic vascular complications, such as coronary microvascular dysfunction. The present study sought to investigate the relationship between coronary microvascular function assessed by intracoronary thermodilution method and glycemic variability on a continuous glucose monitoring system (CGMS). Methods We prospectively enrolled 40 patients with or without known diabetes mellitus who had epicardial coronary artery disease referred for coronary angiography and were not treated with diabetic medications. Of these, two had a significant stenosis in the left main coronary artery and were therefore excluded from the analyses. In the end, 38 patients were equipped with a CGMS and underwent intracoronary physiological assessments in the unobstructed left anterior descending artery. The mean amplitude of glycemic excursion (MAGE) and standard deviation were calculated from the obtained CGMS data as indicators of glucose variability. Results Coronary flow reserve (CFR) was negatively correlated with MAGE (r=-0.328, p=0.044) and standard deviation (r=-0.339, p=0.037) on CGMS, while the index of microcirculatory resistance showed no such correlation. Multivariable linear regression analyses showed that MAGE on CGMS was significantly associated with CFR after adjusting for age, sex, fractional flow reserve and hemoglobin A1c. Conclusion Higher MAGE on CGMS was associated with reduced CFR in stable patients with coronary artery disease, suggesting a potential effect of glycemic variability on coronary microvascular flow regulation. A further study with a larger sample size needs to be conducted to confirm our findings.

Impaired coronary flow reserve in patients with poor type 2 diabetes control: Preliminary results from prospective microvascular dysfunction registry

“…Mechanism in which CFR is impaired by poor glycemia control remains unclear. Glucose level variability amplitude has been recently reported to correlate with CFR values, regardless of DM presence [ 23 ]. Furthermore, impaired coronary flow velocity ratio was associated with significantly higher fasting glucose concentration in diabetic women.…”

Cardiovascular Adverse Outcomes as Challenges on Glycemic Variability Among Patients with Type 2 Diabetes on Intensive Insulin Therapy: The Role of Medical Nutrition Therapy with Automatic Snacking

“…Recently, variability in the daily or monthly BG levels has been likewise linked to DM adverse chronic outcomes like neuropathy, retinopathy, and nephropathy [6][7][8][9][10]. The occurrence of fatal cardiovascular events like stroke, heart failure, and myocardial infarction has also been reported to be associated with glycemic variability (GV) [11][12][13][14][15]. However, it is the severe hypoglycemia occurring during nadirs of BG fluctuations mostly in the postprandial state that has shown to result in acute adverse cardiovascular events with increased morbidity and mortality [16][17][18][19].…”