title: Higher CD163 levels are associated with insulin resistance in hepatitis C virus-infected and HIV-infected adults.
abstract: HIV/hepatitis C virus (HCV) coinfection is associated with insulin resistance, but the mechanism is unclear. We hypothesized that intestinal epithelial damage and the consequent monocyte/macrophage activation and inflammation explain this perturbation.
  
  
  
  Cross-sectional study of 519 adults (220 HIV+/HCV-; 64 HIV-/HCV+; 89 HIV+/HCV+; 146 HIV-/HCV-).
  
  
  
  We used multivariable linear regression to evaluate associations of HIV and HCV with the homeostasis model assessment of insulin resistance (HOMA-IR) and if intestinal fatty (FA) acid binding protein (I-FABP, a marker of gut epithelial integrity), soluble CD14 (sCD14) and soluble CD163 (sCD163) (markers of monocyte/macrophage activation), and IL-6 (an inflammatory cytokine) mediated this association.
  
  
  
  HIV+/HCV+ and HIV-/HCV+ had greater demographic-adjusted HOMA-IR [mean (95% confidence interval (CI)): 1.96 (1.51, 2.54) and 1.65 (1.22, 2.24)] than HIV+/HCV- and HIV-/HCV-[1.41 (1.18, 1.67) and 1.44 (1.17, 1.75), respectively]. After additional adjustment for lifestyle and metabolic factors, HIV+/HCV+ remained associated with 36% (95% CI: 4, 80%) greater HOMA-IR relative to HIV-/HCV-, whereas HIV-/HCV+ and HIV+/HCV- had smaller differences. Adjustment for sCD163 substantially attenuated the difference between HIV+/HCV+ and HIV-/HCV-; adjustment for I-FABP, sCD14, and IL-6 had little effect. Higher sCD163 was independently associated with 19% (95% CI: 7, 33%), 26% (95% CI: 15, 39%), 25% (95% CI: 14, 37%), and 23% (95% CI: 11, 36%) greater HOMA-IR in HIV+/HCV+, HIV-/HCV+, HIV+/HCV-, and HIV-/HCV- (all estimates per doubling of sCD163). I-FABP, sCD14, and IL-6 were not associated with HOMA-IR.
  
  
  
  HIV/HCV coinfection is associated with greater HOMA-IR, even after controlling for demographic, lifestyle, and metabolic factors. sCD163, which appears independent of intestinal epithelial damage and inflammation, partly explains this association. Our findings that the association of sCD163 with HOMA-IR occurred even in the absence of HIV and HCV, indicate that viral and nonviral factors affect sCD163 levels. Its role in insulin resistance needs elucidation.
authors.affiliation: aDepartment of Medicine, University of California, San FranciscobMedical Service, Department of Veteran Affairs Medical Center, San Francisco, CaliforniacDepartment of Medicine, Stroger Hospital and Rush University, Chicago, IllinoisdDepartment of Medicine, Georgetown University Medical Center, Washington, District of Columbia, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Reid
authors.forename: Yifei
authors.initials: Y
authors.lastname: Ma
authors.forename: Rebecca
authors.initials: R
authors.lastname: Scherzer
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Price
authors.forename: Audrey L
authors.initials: AL
authors.lastname: French
authors.forename: Michael W
authors.initials: MW
authors.lastname: Plankey
authors.forename: Carl
authors.initials: C
authors.lastname: Grunfeld
authors.forename: Phyllis C
authors.initials: PC
authors.lastname: Tien
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000097:blood*; D015214:Antigens, Differentiation, Myelomonocytic / Q000097:blood*; D060085:Coinfection / Q000150:complications* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000473:pathology*; D019698:Hepatitis C, Chronic / Q000150:complications / Q000473:pathology*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000097:blood*; D000098902:CD163 Antigen
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000098902:CD163 Antigen; D011956:Receptors, Cell Surface