Increase of plasma IL-6 concentration with age in healthy subjects

The present study demonstrated that plasma IL-6 concentration was higher in older subjects than in younger ones and significantly in the male group (P=0.02); Spearman rank correlation showed that plasma IL-6 concentration was positively correlated with age (r=0.28, N=55, P<0.05); there was a highly significant correlation between the concentrations in plasma IL-6 and IL-1α (r=0.51, N=52, P<0.001). These findings suggest the possibility that age-related changes of plasma IL-6 and IL-1α may provide a pathological basis for the susceptibility to such illness as commonly occurs in elderly people, especially Alzheimer's disease as the two interleukins can induce the production of α1- antichymotrypsin and β-amyloid protein precursor.