Purpose in life and c-reactive protein: An individual-participant meta-analysis of >50,000 adults.

Purpose in life is associated consistently with better health outcomes, which may be due in part to healthier inflammatory profiles. The present research used seven independent cohort studies (total N = 54,491) to evaluate the association between purpose in life and c-reactive protein (CRP), sociodemographic moderators of the association, and whether purpose is associated with elevated CRP cross-sectionally and longitudinally (three cohorts with longitudinal data). Purpose in life had a modest but consistent association with concurrent CRP (meta-analytic b=-.05, 95 % CI=-.06, -.04, p < .001). The association was apparent across age, sex, race, and education, but was slightly stronger among males and relatively younger participants. Purpose was associated cross-sectionally with lower likelihood of elevated CRP defined either as CRP> 3 (meta-analytic OR=.91, 95 % CI=.88,.94, p < .001) or CRP> 10 (meta-analytic OR=.86, 95 % CI=.82,.90, p < .001). Although not apparent in all cohorts, the meta-analysis indicated that purpose was associated with lower likelihood of persistently elevated CRP> 3 (meta-analytic OR=.90, 95 % CI=.828,.976, p = .011) and lower risk of developing elevated CRP> 3 (meta-analytic HR=.92, 95 % CI=.886,.964, p < .001) over the up to 12 years of follow-up. Purpose in life is associated with lower levels of CRP, which may be one mechanism through which purpose is associated with better health outcomes.