title: Racial differences in circulating levels of the soluble receptor for advanced glycation endproducts in middle-aged and older adults.
abstract: Low levels of the soluble receptor for advanced glycation endproducts (sRAGE) have been implicated in a number of chronic diseases. Previous studies indicate that sRAGE levels are ~30% lower in Blacks compared to Whites. However, the reasons for these differences are unclear.
  
  
  
  We aimed to identify predictors of circulating sRAGE biomarkers among Black and White adults at high cardiac risk.
  
  
  
  Serum levels of total sRAGE, endogenous secretory RAGE (esRAGE), carboxymethyl-lysine (CML, a major RAGE ligand), and their ratios were measured in 99 Blacks and 454 Whites.
  
  
  
  Blacks had a more adverse cardiovascular risk profile, as well as lower median levels of total sRAGE (972 vs. 1564pg/ml) and esRAGE (474 vs. 710pg/ml) compared to Whites (p<0.0001). In addition, the proportion of esRAGE was higher in Blacks (47% vs. 44%, p=0.02), as were the CML/total sRAGE (0.89 vs. 0.56ng/pg) and CML/esRAGE (1.72 vs. 1.20ng/pg) ratios (p<0.0001). Racial differences persisted after adjustment for key covariates including age, gender, tobacco use, comorbidities, BMI, blood pressure, glucose, insulin, triglycerides, C-reactive protein, and renal function (p<0.05). Race alone accounted for nearly half of the variability in total sRAGE levels (10.6%; model explained 23.9%). In stratified analyses, gender and heart rate were independently associated with total sRAGE and esRAGE in Whites, while CML and C-reactive protein were associated with total sRAGE in Blacks.
  
  
  
  We identified several independent predictors of sRAGE biomarkers. Notably, Black race was associated with an adverse AGE/RAGE profile, including lower sRAGE and higher CML/sRAGE ratios.
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC. Electronic address: tbrinkle@wakehealth.edu.
authors.forename: Tina E
authors.initials: TE
authors.lastname: Brinkley
authors.affiliation: Department of Biostatistical Sciences, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Leng
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.affiliation: Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Jingzhong
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Internal Medicine, Section on Cardiology, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: Dalane W
authors.initials: DW
authors.lastname: Kitzman
authors.affiliation: Department of Internal Medicine, Section on Cardiology, Wake Forest School of Medicine, Winston-Salem, NC.
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Hundley
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006339:Heart Rate; D006801:Humans; D008239:Lysine / Q000031:analogs & derivatives / Q000097:blood; D008297:Male; D008875:Middle Aged; D044469:Racial Groups; D000067759:Receptor for Advanced Glycation End Products / Q000097:blood*; D012737:Sex Factors; D044465:White People
chemical_list: D002097:C-Reactive Protein; D008239:Lysine; D000067759:Receptor for Advanced Glycation End Products; C000593877:esRAGE protein, human; C048496:N(6)-carboxymethyllysine; C000593871:AGER protein, human
keywords: Advanced glycation endproducts; Carboxymethyl-lysine; Endogenous secretory RAGE; Race; Soluble RAGE