Measures of abdominal obesity assessed for visceral adiposity and relation to coronary risk.

AIMS: We aimed to identify by computed tomography (CT) the best suited of three anthropometric indices that reflect the visceral adipose tissue (VAT), and to discern the relationship between VAT and certain atherogenic risk factors and coronary heart disease (CHD) diagnosis in a population sample which had a high (34%) prevalence of the metabolic syndrome (MS). METHODS: A single-scan CT was performed between the fourth and fifth lumbar vertebrae in 157 unselected men and women aged 34-69 y. Total adipose tissue area, abdominal VAT area and the abdominal sagittal diameter were determined. Diagnosis of CHD was based on clinical findings and Minnesota coding of resting electrocardiograms. RESULTS: Men had significantly higher VAT than women. Linear regression analysis for correlates of abdominal VAT area, in a model comprising age, sex, waist circumference, waist-to-hip ratio (WHR) and body mass index (BMI) identified waist circumference as the only independent variable (P<0.001). Waist circumference in men and BMI in women were the independently associated parameters of sagittal diameter (P<0.001). By stepwise linear regression, it was elicited that VAT area rose significantly by a mean of 6.8 cm2 in men and 3 cm2 in women for every 1 cm increment in waist circumference, independent of WHR. Age in women and (inversely) BMI in men were further independent variables, indicating in men that a lower BMI at a given waist girth suggests the existence of a higher VAT. Apo B and HDL-cholesterol (HDL-C) in men, and the latter in women were independently associated with VAT area in linear regression models that also comprised triglycerides, fasting insulin and C-reactive protein concentrations. In the study sample comprising 13 individuals with a CHD diagnosis, the age-adjusted odds ratio of cutpoints of VAT area > vs <140 cm2 in men and > vs <120 cm2 in women was 11.3 (95% CI (1.37, 93)). CONCLUSIONS: The best surrogate of visceral adiposity across a wide age range is waist circumference, in a population in which MS prevails. Apo B and HDL-C in men, and the latter in women were independently associated with VAT area, which proved to be closely related to CHD risk. A lower BMI at a given waist girth in men suggests the existence of a higher VAT.

Detection and quantification of carotid artery stenosis: efficacy of various Doppler velocity parameters.

OBJECTIVE: The purpose of this study was to evaluate and compare the accuracies of the different Doppler velocity parameters used to grade stenoses of the carotid artery. MATERIALS AND METHODS: Seven velocity parameters determined with Doppler spectra were compared with angiographic findings in 138 carotid bifurcations: the peak systolic and peak end-diastolic velocities in the internal and common carotid arteries, the ratios of peak systolic and peak end-diastolic velocities between the internal and common carotid arteries, and the ratio of peak systolic velocity in the internal carotid artery to peak end-diastolic velocity in the common carotid artery. A receiver-operating-characteristic (ROC) analysis was performed, with and without correction for the bias introduced by preferentially selecting patients for angiography, if the Doppler results indicated a lesion. Multiple regression analysis was performed to predict the percent stenosis and to predict the probability of a 70% or greater stenosis. RESULTS: Of the Doppler parameters, the peak systolic velocity in the internal carotid artery and its ratio to the peak end-diastolic velocity in the common carotid artery were the most accurate and had equivalent test performance (ROC area = 0.94; after correction for verification bias, ROC area = 0.78). In multiple regression analysis, the peak systolic velocity in the internal carotid artery was the most significant parameter, although its ratio to the peak end-diastolic velocity in the common carotid artery had incremental value in detecting a 70% or greater stenosis, and the peak systolic velocity in the common carotid artery provided additional information for quantifying the stenosis. CONCLUSION: The peak systolic velocity in the internal carotid artery is the best single velocity parameter for quantifying a stenosis and for detecting a 70% or greater stenosis.