Self-rated health and C-reactive protein in young adults

Poor self-rated health (SRH) and elevated inflammation and morbidity and mortality are robustly associated in middle- and older-aged adults. Less is known about SRH-elevated inflammation associations during young adulthood and whether these linkages differ by sex.

Data came from the National Longitudinal Study of Adolescent Health. At Wave IV, young adults aged 24–34 reported their SRH, acute and chronic illnesses, and sociodemographic and psychological characteristics relevant to health. Trained fieldworkers assessed medication use, BMI, waist circumference, and also collected bloodspots from which high-sensitivity CRP (hs-CRP) was assayed. The sample size for the present analyses was N = 13,236.

Descriptive and bivariate analyses revealed a graded association between SRH and hs-CRP: Lower ratings of SRH were associated with a higher proportion of participants with hs-CRP >3 mg/L and higher mean levels of hs-CRP. Associations between SRH and hs-CRP remained significant when acute and chronic illnesses, medication use, and health behaviors were taken into account. When BMI was taken into account, the association between SRH and hs-CRP association fully attenuated in females; a small, but significant association between SRH and hs-CRP remained in males.

Poor SRH and elevated hs-CRP are associated in young adults, adjusting for other health status measures, medication use, and health behavior. In males, SRH provided information about elevated hs-CRP that was independent of BMI. In females, BMI may be a better surrogate indicator of global health and pro-inflammatory influences compared to SRH.