title: Severely obese have greater LPS-stimulated TNF-alpha production than normal weight African-American women.
abstract: Obesity is associated with an increase in chronic, low-grade inflammation which has been implicated in the development of type 2 diabetes mellitus and cardiovascular disease. The purpose of this study was to determine whether obesity was associated with an elevation of whole blood lipopolysaccharide (LPS)-stimulated tumor necrosis factor-alpha (TNF-alpha) production. African-American women were recruited from a larger study and assigned to one of five groups based on BMI: normal weight (NORM; BMI 20-25, n = 7), overweight (OVER; BMI 25-30, n = 12), class 1 obese (OB1; BMI 30-35, n = 19), class 2 obese (OB2; BMI 35-40, n = 10), or class 3 obese (OB3; BMI >40, n = 17). Body composition was determined via a whole body dual-energy X-ray absorptiometry (DXA) scan. Venous blood samples were collected following an overnight fast (>8 h), and stimulated with five doses of LPS (Salmonella enteriditis): 80, 40, 20, 10, and 5 microg/ml for 24 h in a 37 degrees C, 5% CO(2) incubator. Following stimulation, TNF-alpha was measured using enzyme-linked immunosorbent assay. OB3 produced 365% more TNF-alpha than NORM at an LPS dose of 20 microg/ml (P < 0.05). When maximal TNF-alpha production was assessed regardless of LPS dose, OB3 produced 230% more than NORM and OVER produced 190% more than NW (P = 0.001). Total and trunk fat mass and BMI were significantly correlated with maximal TNF-alpha production and LPS = 20 microg/ml. Our findings are consistent with previous reports suggesting a relationship between increased adiposity and inflammatory marker production. This is one of the first studies to focus on African-American women, who have higher rates of obesity.
authors.affiliation: Department of Health and Human Performance, University of Houston, Houston, Texas, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Kueht
authors.forename: Brian K
authors.initials: BK
authors.lastname: McFarlin
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Lee
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity / Q000502:physiology; D000328:Adult; D001741:Black or African American / Q000208:ethnology*; D015415:Biomarkers / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood* / Q000208:ethnology*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood* / Q000187:drug effects*
chemical_list: D015415:Biomarkers; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha