Determinants of serum concentrations of lipopolysaccharide-binding protein (LBP) in the adult population: the role of obesity

PLoS One. 2013;8(1):e54600. doi: 10.1371/journal.pone.0054600. Epub 2013 Jan 22.


Background and aim: Assessment of serum concentration of lipopolysaccharide (LPS)-binding protein (LBP) has been suggested as a useful biomarker to indicate activation of innate immune responses to microbial products. We investigated LBP concentrations and associations with demographics, lifestyle factors, and common metabolic abnormalities in adults. We also examined if LBP concentrations were associated with common polymorphisms in genes coding for LBP (rs2232618), CD14 (rs2569190), and TLR4 (rs4986790), the molecules responsible for the innate immune response to LPS, or serum levels of soluble CD14 (sCD14) and proinflammatory cytokines.

Methods: Serum LBP was measured with a commercial immunoassay in a random sample of the adult population (n = 420, 45% males, age 18-92 years) from a single municipality.

Results: Serum LBP concentrations increased with age (P<0.001) and were higher in individuals who were overweight or obese than in normal-weight individuals (P<0.001). Similarly, LBP concentrations were higher in individuals with metabolic syndrome than in individuals without it (P<0.001). Among metabolic syndrome components, LBP concentrations were independently associated with abdominal obesity (P = 0.002) and low concentrations of HDL-cholesterol (P<0.001). Serum LBP concentrations tended to be independently associated with smoking (P = 0.05), but not with alcohol consumption. Likewise, there was not significant association between LBP concentrations and gene polymorphisms. Concentrations of LBP significantly correlated with serum levels of proinflammatory cytokines (IL-6 and IL-8), sCD14, and with liver enzymes.

Conclusions: Serum LBP concentrations increased with age. Overweight, obesity, and having metabolic syndrome (particularly, low HDL cholesterol levels) were associated with higher LBP concentrations. These findings are consistent with microbial exposure playing a role in these inflammatory, metabolic abnormalities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Proteins / genetics
  • Adolescent
  • Adult
  • Age Factors
  • Carrier Proteins / blood*
  • Carrier Proteins / genetics
  • Female
  • Genetic Association Studies
  • Humans
  • Immunity, Innate*
  • Inflammation / blood
  • Inflammation / genetics
  • Inflammation / immunology
  • Lipopolysaccharide Receptors / genetics
  • Male
  • Membrane Glycoproteins / blood*
  • Membrane Glycoproteins / genetics
  • Metabolic Syndrome / blood*
  • Metabolic Syndrome / genetics
  • Metabolic Syndrome / immunology
  • Middle Aged
  • Obesity / blood*
  • Obesity / genetics
  • Obesity / immunology
  • Polymorphism, Single Nucleotide
  • Toll-Like Receptor 4 / genetics


  • Acute-Phase Proteins
  • Carrier Proteins
  • Lipopolysaccharide Receptors
  • Membrane Glycoproteins
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • lipopolysaccharide-binding protein

Grants and funding

This study was supported by the Xunta de Galicia (, Spain (project no. PGIDIT06PXIB918313 and 10CSA918028PR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.