Coronary atherosclerosis is characterized by more severe metabolic, inflammatory and endothelial alterations when compared to carotid atherosclerosis

Background and aims: Several studies have demonstrated that patients affected by coronary or carotid atherosclerosis are at high risk of developing atherosclerotic lesions in other vascular districts, but there are no data available on the specific differences between coronary and carotid atherosclerosis. Therefore, aim of the present study was to evaluate which metabolic, hormonal and inflammatory alterations characterize coronary atherosclerosis compared to carotid atherosclerosis. Materials and methods: We studied 66 patients affected by asymptomatic ischemic cardiopathy (Group 1) and 88 patients affected by carotid vasculopathy (Group 2). Group 1 included patients with a medical history of negative vascular events in other districts, in particular these patients were submitted to a carotid ultrasound that ruled out the presence of atherosclerotic lesions. In Group 2 patients presented a negative medical history for coronary events and a negative ECG for previous ischemic lesions. All patients did not have any known diabetes and fasting plasma glucose was below 126 mg/dl. The two groups were comparable by age, BMI, systolic and diastolic blood pressure, total cholesterol, HDL cholesterol and triglycerides. Plasma glucose, serum insulin and FFA levels were evaluated during an oral glucose load in all subjects and inflammatory and endothelial markers were evaluated in the fasting state. Results: Fasting plasma glucose (107.1±3.6 vs 96.1±2.0 mg/dl; p<0.01), HOMA index (2.90±0.4 vs 1.93±0.3; p<0.003), NOx (18.7±1.60 vs 11.7±0.86 μmol/l; p <0.001), IL-6 levels (4.04±0.64 vs 2.79±0.43 pg/ml; p<0.02) and TNF-alpha levels (19.4±0.1.3 vs 15.7±1.7 pg/ml; p<0.05) were significantly higher in Group 1 when compared to Group 2. After the oral glucose load, 26.5% of Group 1 patients presented normal glucose tolerance compared to 44.5% in Group 2 (p<0.05). An altered glucose homeostasis, i.e. impaired glucose tolerance was found in 40.5% of Group 1 patients, while 33% evidenced type 2 diabetes mellitus. In Group 2, 35% of patients presented impaired glucose tolerance and 20% type 2 diabetes mellitus. FFA levels during the oral glucose load were higher in Group 1 than in Group 2 (60 min: 0.38±0.03 vs 0.23±0.01 μmol/l, p<0.01; 120 min: 0.19±0.02 vs 0.15±0.01 mmol/l, p<0.03). Furthermore, NOx levels during the oral glucose load were significantly lower in Group 1 compared to Group 2 (ΔAUC NOx: -58.4±28.2 vs -13.3±12.1 μmol/l (0-120 min); p<0.0001). Performing a multiple regression analysis, 2h post load plasma glucose was independently related to vascular district (p<0.001), AUC of FFA (p<0.01), HDL cholesterol (p<0.003), AUC of insulin (p<0.01) and basal NOx (p<0.02). Conclusion: Coronary atherosclerosis is characterized by a higher prevalence of abnormal glucose tolerance and insulin resistance, a decreased antilipolytic activity of insulin, and a more proatherogenetic profile than carotid atherosclerosis.