Evaluation of the relations between the presence of the metabolic syndrome and the degree of visceral obesity and the severity of coronary artery disease by coronary angiography.

Background: The prevalence of the metabolic syndrome (MetSy) steadily increases worldwide.

Aim: To evaluate the relation between the presence of MetSy and visceral obesity and the presence of coronary lesions, and to assess correlations between waist circumference and body mass index (BMI) and coronary lesions.

Methods: We studied 105 patients who underwent elective coronary angiography. The study population was divided into four groups depending on the presence of MetSy and visceral obesity. Coronary angiographic evaluation was performed by an invasive cardiologist. For ultimate objective evaluation of the degree of coronary stenoses, quantitative coronary angiography was performed. Based upon coronary angiography results, patients were divided into four groups depending on the severity of coronary artery disease (CAD): with no coronary lesions, with haemodynamically insignificant lesions (1-69% stenosis), with haemodynamically significant lesions (> 70%) in 1 or 2 vessels, and with multivessel disease (> 70% stenoses in 3 vessels or a > 50% stenosis in the left main coronary artery).

Results: Normal coronary arteries were significantly more commonly found in patients without obesity and MetSy (50% of patients). Haemodynamically significant lesions were most frequently found among obese patients with MetSy (40% of patients) and among obese patients without MetSy (38.1% of patients). Concomitant presence of obesity among patients with MetSy (i.e., MetSy with obesity as compared to MetSy without obesity) was not found to be significantly related to the severity of CAD. In addition, advanced CAD was significantly more frequent in obese patients with MetSy compared to the other groups. Isolated visceral obesity in patients without MetSy (i.e., obese patients without MetSy as compared to non-obese patients without MetSy) was found to correlate with haemodynamically significant coronary lesions. When we evaluated nonparametric correlations between waist circumference, BMI; and the severity of CAD, BMI did not correlate with coronary lesions (r = 0.08, p = 0.37). In contrast, a significant correlation was found between waist circumference and the severity of CAD (r = 0.55, p < 0.001). Haemodynamically significant lesions were more significantly more frequent in patients with MetSy compared to patients without MetSy (76% vs. 24%, p < 0.001). Haemodynamically significant lesions were found in 67.7% of patients with isolated visceral obesity compared to 23.2% of non-obese patients without MetSy. In multivariate analysis, CAD was significantly more likely among patients with MetSy regardless of the analysed model (OR 5.3, 95% CI 1.1-25.8, p < 0.05).

Conclusions: 1. The presence of MetSy significantly correlates with haemodynamically significant coronary lesions. 2. The degree of visceral obesity significantly correlates with the severity of CAD. 3. BMI does not correlate with the severity of CAD. 4. Isolated visceral obesity is a weaker determinant of haemodynamically significant coronary lesions compared to MetSy with associated obesity. 5. MetSy is associated with significantly more advanced coronary lesions, i.e. multivessel disease.