title: Interaction between GSTM1 genotype and IL-6 on mortality in older adults: results from the ilSIRENTE study.
abstract: OBJECTIVE
  The inflammatory process is related to oxidative stress and inflammation was proven to be a strong determinant of the aging process and to ultimately lead to death. The aim of the present study was to assess if, in a population of older adults, the effect of antioxidant genes GSTM1 and GSTT1 genotypes on mortality may differ depending on levels of inflammation.
  
  
  METHODS
  Data are from 353 older persons aged ≥80 years enrolled in the ilSIRENTE study. Study population was divided into two groups computed based on the median value of serum IL-6 (low IL-6, n=177 and high IL-6, n=176). All participants were followed up for 48 months.
  
  
  RESULTS
  Mean age of study participants was 85.8 years (Standard Deviation 4.8), 235 (66.6%) were women. Overall 48/177 participant (27.1%) in the low IL-6 group died during the study period, compared with 97/176 (55.1%) in the high IL-6 group (p<0.001). After adjusting for potential confounders, GSTM1 wildtype had no effect on mortality in the low IL-6 group (RR=1.07; 95% CI 0.46-2.47), but it was associated with a significant lower mortality rate in the high IL-6 level (RR=0.33; 95% CI 0.15-0.69). Testing the interaction between IL-6 and GSTM1 genotype, we found a significant result (p=0.02). No significant effect of GSTT1 genotype on mortality was shown in participants with low and high IL-6 level.
  
  
  CONCLUSIONS
  GSTM1 wildtype is associated with reduced mortality among older adults with high levels of inflammation, but not among those with low levels of inflammation.
authors.affiliation: Centro Medicina dell'Invecchiamento, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Onder
authors.forename: Ettore
authors.initials: E
authors.lastname: Capoluongo
authors.forename: Silvia
authors.initials: S
authors.lastname: Giovannini
authors.forename: Paola
authors.initials: P
authors.lastname: Concolino
authors.forename: Andrea
authors.initials: A
authors.lastname: Russo
authors.forename: Rosa
authors.initials: R
authors.lastname: Liperoti
authors.forename: Roberto
authors.initials: R
authors.lastname: Bernabei
authors.forename: Francesco
authors.initials: F
authors.lastname: Landi
mesh_terms: D000369:Aged, 80 and over; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000235:genetics* / Q000401:mortality; D015850:Interleukin-6 / Q000097:blood*; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D005982:Glutathione Transferase; D015850:Interleukin-6; C413545:glutathione S-transferase T1