title: Adiponectin multimers and metabolic syndrome traits: relative adiponectin resistance in African Americans.
abstract: African Americans (AAs) tend to have lower total adiponectin levels compared to European Americans (EA); however, it is not known whether race affects adiponectin multimer distribution and their relationships to metabolic traits. We measured total adiponectin, high molecular weight (HMW), low molecular weight (LMW) (i.e., hexamer), and trimer adiponectin in 132 normoglycemic premenopausal women (75 AAs, 57 EAs), together with measures of total and abdominal fat, plasma lipids, insulin sensitivity (S(i)), and genetic admixture estimates. We found that lower total adiponectin in AAs was explained by reduced LMW, and trimer forms because levels of HMW did not differ between races. In EAs, HMW was highly correlated with multiple metabolic syndrome traits. In contrast, the LMW and trimer forms were most highly correlated with metabolic traits in AAs, including abdominal adiposity, lipids, and S(i). At similar levels of visceral adiposity, AAs exhibited significantly lower LMW adiponectin than EAs. Similarly, at comparable levels of HMW and LMW adiponectin, AAs were more insulin resistant than their EA counterparts. In conclusion, (i) serum adiponectin is lower in AAs predominantly as a result of reduced concentrations of LMW and trimers multimeric forms; (ii) LMW and trimer, not HMW, are most broadly correlated with metabolic traits in AAs. Thus, HMW adiponectin may exert less bioactivity in explaining the metabolic syndrome trait cluster in populations of predominant African genetic background.
authors.affiliation: Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA. larac@uab.edu
authors.forename: Cristina
authors.initials: C
authors.lastname: Lara-Castro
authors.forename: Erin C
authors.initials: EC
authors.lastname: Doud
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Tapia
authors.forename: Andres J
authors.initials: AJ
authors.lastname: Munoz
authors.forename: Jose R
authors.initials: JR
authors.lastname: Fernandez
authors.forename: Gary R
authors.initials: GR
authors.lastname: Hunter
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Gower
authors.forename: W Timothy
authors.initials: WT
authors.lastname: Garvey
mesh_terms: D052242:Adiponectin / Q000097:blood*; D000328:Adult; D001741:Black or African American; D001823:Body Composition; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000208:ethnology; D050152:Intra-Abdominal Fat; D008970:Molecular Weight; D017697:Premenopause; D014280:Triglycerides / Q000097:blood; D044465:White People
chemical_list: D052242:Adiponectin; D014280:Triglycerides; D002784:Cholesterol