Inflammatory proteins are related to total and abdominal adiposity in a healthy adolescent population: the AVENA Study

Background:Inadults,obesityischaracterizedbyastateofchronic low-grade inflammation accompanied by moderately high concentrationsofacutephaseinflammatoryproteins.RecentresultsregardingC-reactiveprotein(CRP)pointtoasimilarstatusinadolescents; however,studiesofassociationsoftheseruminflammatoryproteins CRP, ceruloplasmin, and complement factors C3 and C4 with body fat distribution remain scarce. Objective: We aimed to establish the possible relations of serum inflammatory proteins with body fat estimates and body fat distribution in an apparently healthy adolescent population. Design: This report included 472 adolescents (248 males and 224 females)aged13–18.5ywhowererecruitedfromtheSpanishcrosssectional multicenter AVENA Study for whom anthropometric and immunologic data were complete. The concentrations of the serum proteins and the in vitro production of cytokines (interleukin 6 and tumornecrosisfactor)byisolatedandstimulatedwhitebloodcells were measured. Relations with anthropometric measurements were explored by using simple and partial correlations. Results: CRP, C3, and C4 were correlated with central obesity (as measured by waist circumference) and total body fat in both sexes (P 0.01) and with ceruloplasmin in females only. After further adjustment for BMI, C3 remained independently associated with central obesity (P 0.05). Production of the cytokines by white blood cells did not seem to be affected by an excess of body fat. Conclusions: Total body fat seems to be associated with a chronic low-gradesystemicinflammationinapparentlyhealthyadolescents. Central obesity is independently associated with C3 concentrations, whichmakesthismarkerespeciallyinterestingforfurtherstudiesof obesity-related diseases. Am J Clin Nutr 2006;84:505–12.