title: Association between -308 G/A TNF-α polymorphism and appendicular skeletal muscle mass index as a marker of sarcopenia in normal weight obese syndrome.
abstract: OBJECTIVE
  Normal weight obese (NWO) syndrome is characterized by normal body mass index (BMI), but high amount of fat mass and reduced lean mass. We evaluated allelic frequency of the G/A -308 TNF-α polymorphism and prevalence of sarcopenia in NWO.
  
  
  METHODS
  We enrolled 120 Italian healthy women, distinguished into 3 groups: normal weight (NW); NWO, and preobese-obese (PreOB/OB) and evaluated anthropometric parameters, body composition by dual X-ray absorptiometry, blood tests, and genotyping of G/A -308 TNF-α polymorphism.
  
  
  RESULTS
  We found a positive association between sarcopenic obesity and -308 TNF-α polymorphism. All obese women were sarcopenic and were no carrier of mutation (G/G). Among all G/G, NWO showed significant differences in lean mass and total body lean mass (TBLean) with respect to NW and PreOB/OB (P < 0.001). Regarding appendicular skeletal muscle mass index values, 4.21% of NW were sarcopenic (50% G/G and 50% G/A); the same percentage was observed in NWO subjects (100% G/G). Moreover, 2.10% of PreOB/OB were sarcopenic and all were G/G.
  
  
  CONCLUSIONS
  Our study suggests that TNF-α polymorphism contributes to sarcopenic obesity susceptibility, in association with body composition. This is the first study that shows the importance of TNF-α polymorphism to determine TBLean variation in NWO syndrome.
authors.affiliation: Division of Clinical Nutrition and Nutrigenomic, Department of Biomedicine and Prevention, University of Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Di Renzo
authors.forename: F
authors.initials: F
authors.lastname: Sarlo
authors.forename: L
authors.initials: L
authors.lastname: Petramala
authors.forename: L
authors.initials: L
authors.lastname: Iacopino
authors.forename: G
authors.initials: G
authors.lastname: Monteleone
authors.forename: C
authors.initials: C
authors.lastname: Colica
authors.forename: A
authors.initials: A
authors.lastname: De Lorenzo
mesh_terms: D050154:Adiposity / Q000235:genetics; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D055948:Sarcopenia / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D055815:Young Adult
chemical_list: C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha