title: [Association between carbonyl proteins and tumor necrosis factor alpha with muscle strength in young and older women: exploratory study].
abstract: BACKGROUND
  It has recently been proposed that there is a close relationship between oxidative stress and low-grade chronic inflammation. Both processes have been related separately to muscle function in older adults (OA). Nevertheless, it still has not been determined if this relationship is present particularly in OA. The objective of this study was to determine the relationship between the plasma levels of TNF-α and carbonyl proteins (CP) and muscle strength in a group of young and older women.
  
  
  METHODS
  An exploratory study was conducted on 13 older and 8 young women, in whom the plasma levels of CP and TNF-α were measured. Muscle strength was measured by handgrip test, quadriceps voluntary maximal isometric strength, arm curl, and the 30 second sit to stand test.
  
  
  RESULTS
  There were no differences in the plasma levels of CP and TNF-α between the groups, but there was relationship between the biomarkers only in the OA group. A non-linear relationship was observed between CP and quadriceps voluntary maximal isometric strength only in the OA group (R(2)=36.2; P=.038). For TNF-α there were no significant association with any of the applied tests.
  
  
  CONCLUSIONS
  There is an association between CP and quadriceps voluntary maximal isometric strength only in the OA group, which could indicate a deleterious action of oxidative stress on muscle function, particularly in aging.
authors.affiliation: Escuela de Kinesiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile. Electronic address: sergio.martinez@uach.cl.
authors.forename: Sergio Francisco
authors.initials: SF
authors.lastname: Martínez Huenchullán
authors.affiliation: Departamento de Kinesiología, Facultad de Ciencias de la Salud, Universidad Católica del Maule, Talca, Chile.
authors.forename: Eladio Bernabé
authors.initials: EB
authors.lastname: Mancilla Solorza
mesh_terms: D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D053580:Muscle Strength; D050050:Protein Carbonylation; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha
keywords: Aging; Carbonilación proteica; Envejecimiento; Factor necrótico tumoral alfa; Fuerza muscular; Muscle strength; Protein carbonylation; Tumor necrosis factor-alpha