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 cm(2) in men and 3 cm(2) 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 cm(2) in men and > vs <120 cm(2) 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.