Fig. 1

Kaplan-Meier survival curves for the elderly population that was classified according to quartiles of IL-6 concentrations. a. In the successfully aging subgroup, the 1-year mortality rates were 1.0 % for the <1^st quartile, 0.6 % for the 1^st-2^nd quartile, 4.1 % for the 2^nd-3^rd quartile, and 6.8 % for the >3^rd quartile. The differences between the <1^st quartile and all of the other quartiles were significant (all p < 0.001). b. In the subgroup of individuals who suffered from aging-related diseases/disability, the 1-year mortality rates were 2.9 % for the <1^st quartile, 5.7 % for the 1^st-2^nd quartile, 10.0 % for the 2^nd-3^rd quartile, and 15.8 % for the >3^rd quartile. The differences between the <1^st quartile and all of the other quartiles were significant (all p < 0.001)