title: Association between serum interleukin-6 concentrations and mortality in older adults: the Rancho Bernardo study.
abstract: BACKGROUND
  Interleukin-6 (IL-6) may have a protective role in acute liver disease but a detrimental effect in chronic liver disease. It is unknown whether IL-6 is associated with risk of liver-related mortality in humans.
  
  
  OBJECTIVE
  To determine if IL-6 is associated with an increased risk of all-cause, cardiovascular disease (CVD), cancer, and liver-related mortality.
  
  
  METHODS
  A prospective cohort study included 1843 participants who attended a research visit in 1984-87. Multiple covariates were ascertained including serum IL-6. Multivariable-adjusted Cox proportional hazards regression analyses were used to examine the association between serum IL-6 as a continuous (log transformed) variable with all-cause, CVD, cancer, and liver-related mortality. Patients with prevalent CVD, cancer and liver disease were excluded for cause-specific mortality.
  
  
  RESULTS
  The mean (± standard deviation) age and body-mass-index (BMI) of participants was 68 (± 10.6) years and 25 (± 3.7) Kg/m(2), respectively. During the 25,802 person-years of follow-up, the cumulative all-cause, CVD, cancer, and liver-related mortality were 53.1% (N = 978), 25.5%, 11.3%, and 1.3%, respectively. The median (± IQR) length of follow-up was 15.3 ± 10.6 years. In multivariable analyses, adjusted for age, sex, alcohol, BMI, diabetes, hypertension, total cholesterol, HDL, and smoking, one-SD increment in log-transformed serum IL-6 was associated with increased risk of all-cause, CVD, cancer, and liver-related mortality, with hazard ratios of 1.48 (95% CI, 1.33-1.64), 1.38 (95% CI, 1.16-1.65), 1.35 (95% CI, 1.02-1.79), and 1.88 (95% CI, 0.97-3.67), respectively. CRP adjustment attenuated the effects but the association between IL-6 and all-cause and CVD mortality remained statistically significant, independent of CRP levels.
  
  
  CONCLUSIONS
  In community-dwelling older adults, serum IL-6 is associated with all-cause, CVD, cancer, and liver-related mortality.
authors.affiliation: Department of Medicine, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Lee
authors.forename: Ricki
authors.initials: R
authors.lastname: Bettencourt
authors.forename: David
authors.initials: D
authors.lastname: Brenner
authors.forename: Thuy-Anh
authors.initials: TA
authors.lastname: Le
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
authors.forename: Rohit
authors.initials: R
authors.lastname: Loomba
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000401:mortality; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008107:Liver Diseases / Q000097:blood / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000401:mortality; D016016:Proportional Hazards Models; D011446:Prospective Studies
chemical_list: D015850:Interleukin-6