Salivary Biomarkers of Chronic Psychosocial Stress and CVD Risks: A Systematic Review

Background: The use of salivary biomarkers in stress research is increasing, and the precision and accuracy with which researchers are able to measure these biomarkers have dramatically improved. Chronic psychosocial stress is often linked to the pathogenesis of cardiovascular disease (CVD). Salivary biomarkers represent a noninvasive biological method of characterizing the stress phenomenon that may help to more fully describe the mechanism by which stress contributes to the pathogenesis and outcomes of CVD. Objectives: We conducted a systematic review of 40 research articles to identify the salivary biomarkers researchers have most commonly used to help describe the biological impact of chronic psychosocial stress and explore its associations with CVD risk. We address strengths and weaknesses of specimen collection and measurement. Methods: We used PubMed, CINAHL, EBSCOhost, Web of Science, BIOSIS Previews, Biological Sciences (ProQuest), and Dissertations/Theses (ProQuest) to retrieve 387 initial articles. Once we applied our inclusion/exclusion criteria to specifically target adult human studies dealing with chronic stress rather than acute/laboratory-induced stress, 40 studies remained, which we synthesized using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Results: Cortisol was the biomarker used most frequently. Sources of psychosocial stress included job strain, low socioeconomic status, and environmental factors. Overall, psychosocial stress was associated with CVD risks such as vascular pathology (hypertension, blood pressure fluctuation, and carotid artery plaque) as well as metabolic factors such as abnormal blood glucose, dyslipidemia, and elevated cardiac enzymes. Conclusion: Diverse salivary biomarkers have been useful in stress research, particularly when linked to CVD risks.