Carotid artery atherosclerosis and stiffness: comparison of different metabolic measures

Background. Recently a new index of metabolic impairment has been introduced: the triglycerides/HDL ratio (TG/HDL). This index indicates an atherogenic lipid profile and an increased risk for the development of common atherosclerosis. Purpose. To evaluate in a population of non diabetic patients the role of TG/HDL ratio compared to non-HDL cholesterol and insulin resistance in predicting early carotid atherosclerosis and stiffness. Methods. The study population consisted of 377 non-diabetic asymptomatic patients (mean age 54 ± 14 years; 242 females, BMI 34.6 ± 8 Kg/m2) referred to our Department for clinical evaluation and primary prevention. All patients underwent a high definition carotid ultrasound examination implemented by an echo-tracking system. In all cases, we evaluated beta-index vascular stiffness, intimal media thickness (IMT) values and the presence of carotid vascular plaque defined as IMT > 1.5 mm. Complete lipid profile was obtained as well as insulin resistance by means of HOMA index. Non-HDL cholesterol was used instead of LDL estimation by Friedewald formula because the high prevalence of hypertriglyceridemia. Results. Mean IMT was 0.87 ± 0.17 mm, mean beta index was 7.3 ± 2.8. One hundred forty one pts (37%) showed a carotid plaque at the ultrasound evaluation. In a model considering systolic blood pressure, glicemia, HOMA index, triglycerides, TG/HDL ratio and non-HDL cholesterol, only non-HDL cholesterol emerged as predictive variable for elevated IMT, elevated beta stiffness and presence of carotid plaque (p <.001). Conclusion. In a population of non diabetic patients in primary prevention, non-HDL cholesterol is superior in predicting carotid atherosclerosis and stiffness than triglycerides/HDL ratio and HOMA index.