Inflammatory marker trajectories associated with frailty and ageing in a 20-year longitudinal study

Objective The aim of this exploratory study was to investigate the development of low-grade inflammation during ageing and its relationship with frailty. Methods The trajectories of 18 inflammatory markers measured in blood samples, collected at 5-year intervals over a period of 20 years from 144 individuals aged 65-75 years at the study endpoint, were related to the degree of frailty later in life. Results IFN-gamma-related markers and platelet activation markers were found to change in synchrony. Chronically elevated levels of IL-6 pathway markers, such as CRP and sIL-6R, were associated with more frailty, poorer lung function and reduced physical strength. Being overweight was a possible driver of these associations. More and stronger associations were detected in women, such as a relation between increasing sCD14 levels and frailty, indicating a possible role for monocyte overactivation. Multivariate prediction of frailty confirmed the main results, but predictive accuracy was low. Conclusion In summary, we documented temporal changes in and between inflammatory markers in an ageing population over a period of 20 years, and related these to clinically relevant health outcomes.