Self-rated Health Is Related to Levels of Circulating Cytokines

OBJECTIVE: Self-rated health is a powerful and independent predictor of long-term health, but its biological basis is unknown. Because factors associated with poor self-rated health (eg, pain, daily discomforts, and low energy and fitness) resemble symptoms of a generalized cytokine-induced sickness response, we examined the relationship between circulating cytokines and self-rated health. METHODS: In 265 consecutive primary health care patients (174 women and 91 men), we examined self-rated and physician-rated health, circulating levels of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1ra), IL-6, and tumor necrosis factor (TNF)-alpha as determined from plasma samples using high-sensitivity enzyme-linked immunoassay. RESULTS: Self-rated health correlated with levels of IL-1beta (r = 0.27; p <.001), IL-1ra (r = 0.19; p <.05) and TNF-alpha (r = 0.46; p <.001) in women but not in men. Thus, poorer subjective health was associated with higher levels of inflammatory cytokines. Even when controlling for age, education, physical health, and diagnoses in multiple regression analyses, self-rated health was an independent and more robust predictor of cytokine levels than physician-rated health. CONCLUSIONS: The present findings suggest that an individual's health perception may be coupled to circulating cytokines. Because epidemiological research established that self-rated health predicts morbidity and mortality, the biological correlates and mechanisms of self-rated health need to be understood.