Usefulness of Abdominal Visceral Fat Thickness Using Ultrasonography as a Predictor of Metabolic Syndrome and Atherosclerosis in Obese Adults

Kim, Jong Sub; Lee, Hui Joong; Kim, Jong Yeol; Kang, Duk Sik; Lee, Duk Hee; Kam, Sin; Lee, Sung Kook; Lee, Jeong Beom

Abstract

BACKGROUND: Abdominal obesity with visceral fat accumulation is known to be an important contributing factor to the development of metabolic syndrome and atherosclerosis. Therefore, estimating the precise amount of visceral fat is an important step in assessing the risks of these diseases. Recently, it has been reported that ultrasonography is a simple, noninvasive and reliable method for visceral fat evaluation. This study was undertaken primarily to investigate how visceral fat thickness measured by ultrasonography correlates with atherosclerotic risk factors including components of metabolic syndrome, and secondly to assess its usefulness as a predictor of metabolic syndrome and atherosclerosis in obese adults.
METHODS
Total of 200 obese (BMI > or = 25 kg/m2) subjects (109 men and 91 women) were recruited in this study. An ultrasonographic evaluation of abdomen just above the umbilicus was conducted to obtain three ultrasonographic indexes, visceral fat thickness (VFT), subcutaneous fat thickness (SFT), and visceral to subcutaneous fat thickness ratio (VSR). The measurements were taken cautiously to avoid distortions caused by respiration or compression. Also, an ultrasonographic evaluation of carotid artery was conducted to evaluate intima-media thickness (IMT) and to determine the presence of atherosclerotic plaque. Concurrently serum total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride, fasting serum glucose, blood pressure and body mass index (BMI) were measured.
RESULTS
Of the three ultrasonographic indexes, VFT was most closely correlated with atherosclerotic risk factors, and VFT was correlated with age, BMI, systolic blood pressure, fasting serum glucose, triglyceride, HDL-cholesterol and carotid IMT in both male and female subjects. VFT was significantly higher in the subjects with metabolic syndrome and carotid atherosclerotic plaque than in those without these diseases in both men and women. According to multiple logistic regression analysis, VFT was an independent determinant of metabolic syndrome in both men and women, and an independent determinant of carotid atherosclerotic plaque in only men.
CONCLUSION
VFT using ultrasonography significantly correlates with atherosclerotic risk factors including components of metabolic syndrome in obese adults. Also, VFT using ultrasonography can be used as a predictor of metabolic syndrome in obese adults and carotid atherosclerosis in obese male adults.