ABSTRACT
BACKGROUND: Despite the recognition that central obesity plays a critical role in chronic disease, few large-scale imaging studies have documented human variation in abdominal adipose tissue patterning. OBJECTIVE: We aimed to compare the associations between abdominal subcutaneous adipose tissue (ASAT) and visceral abdominal tissue (VAT), which were measured at different locations across the abdomen, and the presence of the metabolic syndrome (MS; National Cholesterol Education Program Adult Treatment Panel III definition) and individual cardiometabolic risk factors. DESIGN: This study included 713 non-Hispanic whites aged 18-86 y, in whom VAT and ASAT were assessed by using multiple-image magnetic resonance imaging. The anatomical position of the magnetic resonance image containing the maximum VAT area for each subject was used as a measure of VAT patterning. Multivariate linear and logistic regression analyses were used to examine the relation of VAT, ASAT, and VAT patterning to cardiometabolic risk. RESULTS: VAT mass was a stronger predictor of the MS than was ASAT mass, but ASAT mass (and other measures of subcutaneous adiposity) had signification interactions with VAT mass, whereby elevated ASAT reduced the probability of MS among men with high VAT (P = 0.0008). There was variation across image locations in the association of VAT area with the MS in men, and magnetic resonance images located 4-8 cm above L4-L5 provided the strongest correlations between VAT area and cardiometabolic risk factors. Subjects whose maximum VAT area was higher in the abdomen had higher LDL-cholesterol concentrations (R(2) = 0.07, P < 0.0001), independent of age and adiposity. CONCLUSION: Further studies are needed to confirm the effects of VAT patterning on cardiometabolic risk.
Subject(s)
Body Composition/physiology , Cardiovascular Diseases/epidemiology , Intra-Abdominal Fat/physiopathology , Metabolic Syndrome/epidemiology , Obesity/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Cardiovascular Diseases/etiology , Cardiovascular Diseases/metabolism , Female , Humans , Intra-Abdominal Fat/metabolism , Linear Models , Logistic Models , Magnetic Resonance Imaging , Male , Metabolic Syndrome/etiology , Metabolic Syndrome/metabolism , Middle Aged , Multivariate Analysis , Predictive Value of Tests , Risk Factors , Subcutaneous Fat/metabolism , Subcutaneous Fat/physiopathologyABSTRACT
OBJECTIVE: We tested sex, race, and age differences in the patterning of visceral adipose tissue (VAT) and subcutaneous adipose tissue. RESEARCH METHODS AND PROCEDURES: Contiguous 1-cm-thick magnetic resonance (MR) images of the abdomen were collected from 820 African-American and white adults. Repeated-measures ANOVA was used to examine the effects of image location, sex, race, and age (>or=50 vs. <50 years) on adipose tissue areas. Maximum VAT area was identified for each subject from the raw data. RESULTS: Compared to women, men had greater total VAT volume (p < 0.0001), and their maximum VAT area occurred higher in the abdomen (p < 0.0001). Among white men, maximim VAT area most frequently occurred 5 to 10 cm above L4-L5, whereas in the other groups, maximim VAT area most frequently occurred 1 to 4 cm above L4-L5 (p < 0.0001). African-American men had greater total VAT volume than African-American women (p < 0.01), but this sex difference was only significant using single images cranial to L4-L5 + 2 cm. Age-related increases in VAT tended to be greatest 5 to 10 cm above L4-L5 in men and near L4-L5 in women. DISCUSSION: A single MR image 5 to 10 cm above L4-L5 may allow more accurate conclusions than the L4-L5 image regarding group differences in visceral adiposity.
