Inflammatory cytokines, behaviour and age as determinants of self-rated health in women

Self-rated health is a powerful and independent predictor of long-term health, but its biological basis is unknown. We have shown previously that self-rated health is associated with increased levels of circulating cytokines in women. The main aim of the present study was to increase the understanding of the association between markers of wellbeing, such as self-rated health, and cytokines and to investigate the impact of age on these associations. In 174 female consecutive primary health care patients divided into three age groups, we examined subjective ratings of health and aspects of wellbeing and circulating levels of IL (interleukin)-1β, IL-1ra (IL-1 receptor antagonist), IL-6 and TNF-α (tumour necrosis factor-α). Poor self-rated health was significantly associated with higher levels of TNF-α in all of the age groups. For IL-1β and IL-1ra, the correlations with self-rated health were significant only in the oldest age group. Lower ratings of other measurements of health and wellbeing were related to higher levels of cytokines, most pronounced for TNF-α and IL-1β, and in the middle and olderst age groups. More symptoms resembling a sickness response induced by inflammation were implicated to be associated with lower self-rated health. The strength of the association between inflammatory cytokines and poor health perception increased with advanced age, indicating an increased vulnerability for inflammatory activity during aging. It is suggested that higher levels of TNF-α are connected to a sickness response that, in turn, is connected to self-rated health. The results provide a possible psychobiological basis to understand better diffuse subjective symptoms and poor subjective health in women.