IL6 and glycogen storage disease VI: We found that longer survival was associated with a lower IL-6 concentration, even after adjusting for these covariates, in the entire study group: HR = 1.042 per each pg/mL (95 % CI: 1.029–1.055, p < 0.001), the successfully aging subgroup: HR = 1.112 per each pg/mL (95 % CI: 1.069–1.155, p < 0.001), as well as in study participants with aging-related diseases/disability: HR = 1.031 per each pg/mL (95 % CI: 1.018–1.045, p < 0.001).