ABSTRACT
The purpose of this study was to determine whether racial/ethnic differences exist in the relationship between visceral adipose tissue (VAT) and selected inflammatory biomarkers. Subjects included 136 African-American, 133 Hispanic, and 100 white men and women, aged > or =45. Waist circumference and BMI were measured using standard methods. Total VAT, and VAT and subcutaneous adipose tissue (SAT) at the L4L5 spinal level were measured using computed tomography. Interleukin-6 (IL-6), C-reactive protein (CRP), and fibrinogen were measured from fasting blood samples. Results revealed that waist circumference and BMI were similar among groups but African Americans had significantly lower L4L5 VAT compared with Hispanics and whites. Despite lower VAT, African-American men had similar concentrations of inflammatory biomarkers. On the other hand, African-American women had higher CRP and IL-6 than white women, and higher fibrinogen than both Hispanic and white women. After controlling for L4L5 VAT, L4L5 SAT, and age, African-American women had higher concentrations of IL-6 and fibrinogen. Stratified analyses for CRP indicated that L4L5 SAT was associated with CRP in African-American and white women after controlling for L4L5 VAT and age, but that the reverse was not true. These data indicate that African Americans had lower VAT but similar or higher concentrations of inflammatory biomarkers. African-American women consistently displayed greater inflammation compared with whites, even after controlling for VAT or SAT.
Subject(s)
Black or African American/ethnology , Hispanic or Latino/ethnology , Inflammation/blood , Inflammation/ethnology , Intra-Abdominal Fat/physiopathology , White People/ethnology , Aged , Biomarkers/blood , Body Composition/physiology , Body Mass Index , C-Reactive Protein/metabolism , Female , Fibrinogen/metabolism , Humans , Inflammation/physiopathology , Interleukin-6/blood , Male , Middle Aged , Subcutaneous Fat/physiopathology , Waist CircumferenceABSTRACT
BACKGROUND: Increased visceral adipose tissue (VAT) is thought to be a risk factor for cardiovascular and metabolic diseases. There are only limited data on whether VAT loss after laparoscopic gastric banding surgery (LGBS) is related to risk factor reduction. This study determined whether improvements in risk markers, in particular insulin resistance, were related to VAT reduction at 6 months after LGBS (T2). METHODS: Thirty-four LGBS patients and 17 normal weight controls underwent initial and T2 testing. Fasting venous blood samples were taken to evaluate glucose, insulin, hemoglobin A(1c), lipids, C-reactive protein (CRP), and hormone profiles. Insulin resistance was estimated using the homeostasis model assessment (HOMA) index. VAT was measured using CT techniques. Data were analyzed using repeated measures ANOVA and regression analysis. RESULTS: Results at T2 showed that patients had significant improvements in body composition, HOMA, and hemoglobin A(1c). There were also reductions in plasma renin activity and leptin, and increases in ghrelin and GLP-1. Reductions in VAT were significantly correlated with reductions in insulin, HOMA, and glucose. While high density lipoprotein cholesterol, triglycerides, CRP, and the apolipoprotein A1/B ratio were also improved, VAT reduction was significantly correlated only with an increased apolipoprotein A1/B ratio. CONCLUSION: These data indicate that 6 months after LGBS there were significant improvements in many cardiovascular and metabolic risk markers. However, VAT reduction was most strongly associated with reductions in insulin resistance. Body weight loss was not associated with markers of improved insulin sensitivity.
Subject(s)
Adiposity/physiology , Gastroplasty , Insulin Resistance/physiology , Intra-Abdominal Fat , Laparoscopy , Obesity, Morbid/surgery , Adult , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Female , Follow-Up Studies , Humans , Male , Obesity, Morbid/complications , Obesity, Morbid/metabolism , Risk Factors , Time Factors , Treatment Outcome , Weight Loss/physiologyABSTRACT
OBJECTIVE: BMI and waist circumference are used to define risk from excess body fat. Limited data in women suggest that there may be racial/ethnic differences in visceral adipose tissue (VAT) at a given BMI or waist circumference. This study tested the hypothesis that racial/ethnic differences exist in both men and women in the relationship of anthropometric measures of body composition and computed tomography (CT)-determined VAT or subcutaneous adipose tissue (SAT). METHODS AND PROCEDURES: Subjects included 66 African American, 72 Hispanic, and 47 white men and women, aged > or =45. Waist circumference and BMI were measured using standard methods. Total abdominal and L4L5 VAT and SAT were measured using CT. RESULTS: Among both men and women, groups did not differ in waist circumference or BMI. White men had greater L4L5 VAT than African-American men, and both white and Hispanic men had greater total VAT than African-American men. Among women, Hispanics and whites had greater L4L5 VAT than African Americans, and Hispanics had greater total VAT than African Americans. The slope of the linear relationship between BMI or waist circumference and VAT was lower in African Americans than in Hispanics and/or whites. DISCUSSION: Middle-aged and older African-American men and women had lower VAT despite similar BMI and waist circumference measurements. Altered relationships between anthropometric measures and VAT may have implications for defining metabolic risk in different populations. Different waist circumference or BMI cutoff points may be necessary to adequately reflect risk in different racial/ethnic groups.
