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.