OBJECTIVES: This study sought to investigate the effect of daily glucose 
fluctuation on coronary plaque properties in patients with coronary artery 
disease (CAD) pre-treated with lipid-lowering therapy.
BACKGROUND: There is growing evidence that glucose fluctuation, as a residual 
risk apart from dyslipidemia, is an important factor contributing to the 
development of CAD.
METHODS: This prospective study enrolled 70 consecutive CAD patients who were 
referred for percutaneous coronary intervention and whose low-density 
lipoprotein cholesterol level was <120 mg/dl under statin treatment or <100 
mg/dl without statins. Daily glucose fluctuation was analyzed by measuring the 
mean amplitude of glycemic excursion (MAGE). The plaque properties in the 
culprit and nonculprit lesions were assessed by virtual histology intravascular 
ultrasound, and the volume percentage of necrotic core within the plaque (%NC) 
and the presence of thin-cap fibroatheroma were evaluated.
RESULTS: In total, 165 lesions were evaluated in 70 patients (40 diabetic and 30 
nondiabetic patients). %NC was well correlated with MAGE (r = 0.490, p <0.001). 
A linear mixed effect model showed that MAGE had the strongest effect on %NC 
(coefficient β = 0.080 ± 0.020 [standard error], p < 0.001). The generalized 
linear mixed effect model revealed that MAGE was the only independent predictor 
of the presence of thin-cap fibroatheroma (odds ratio: 1.037; 95% confidence 
interval: 1.010 to 1.065; p = 0.007).
CONCLUSIONS: Daily glucose fluctuation may have an effect on coronary plaque 
vulnerability in patients with CAD pre-treated with lipid-lowering therapy. 
Further investigations should address the rationale for the early detection and 
control of glucose fluctuation in the era of universal statin use for CAD 
patients.