Salivary and Serum Analytes and Their Associations with Self-rated Health Among Healthy Young Adults

Background: Understanding the biological processes underlying poor self-rated health (SRH) can inform prevention efforts. The COVID-19 pandemic highlighted the importance of using self-reported measures and self-collected biospecimens, such as saliva, to understand physiological functioning and assist with health surveillance and promotion. However, the associations between salivary analytes and SRH remain understudied. The current study addresses this gap.

Methods: In a laboratory-based study, 99 healthy adults (M_age = 23.8 years, SD = 4.5, 55% men, 43% non-Hispanic White) reported their SRH and provided saliva and blood samples that were assayed for adiponectin, C-reactive protein (CRP), uric acid (UA), and cytokines (IL-1β, IL-6, IL-8, TNF-α). Principal component analyses assessed the component loadings and generated factor scores for saliva and serum analytes. Binary logistic regressions examined the associations between these components and poor SRH.

Results: Salivary analytes loaded onto two components (component 1: adiponectin and cytokines; component 2: CRP and UA) explaining 58% of the variance. Serum analytes grouped onto three components (component 1: IL-8 and TNF-α; component 2: CRP, IL-1β, and IL-6; component 3: adiponectin and UA) explaining 76% of the variance. Higher salivary component 1 scores predicted higher odds of reporting poor SRH (OR 1.53, 95%CI [1.10, 2.11]). Higher serum component 2 scores predicted higher odds of reporting poor SRH (OR 2.37, 95%CI [1.20, 4.67]). When examined in the same model, salivary component 1 (OR 1.79, 95%CI [1.17, 2.75]) and serum component 2 were associated with poorer SRH (OR 7.74, 95%CI [2.18, 27.40]).

Conclusions: In our sample, whether measured in saliva or serum, indices of inflammatory processes were associated with SRH.