Exploring the Potential Clinical Applications of Salivary Cortisol in the Diagnosis and Management of Cushing’s Syndrome, Diabetes, Depression, and Periodontal Disease: A Systematic Review

Current research primarily aims to investigate the potential of salivary cortisol for early diagnosis as well as clinical management and monitoring of disease progression. Its utility extends to a range of multidisciplinary settings, encompassing conditions, such as Cushing's syndrome, stress, and depression, pre-diabetes, type 2 diabetes, and periodontal disease, within dentistry. This systematic review aimed to analyze recent literature on the use of salivary cortisol as a biomarker for various clinical and pre-clinical conditions, including stress, depression, diabetes, Cushing's Syndrome (CS), and periodontal disease. Specifically, the review sought to evaluate its application in screening, diagnosis, clinical management, and monitoring disease progression.

Employing PubMed (MEDLINE) and Scopus databases, the search strategy utilized Medical Subject Heading (MeSH) terms, including “Cushing’s syndrome”, “diabetes mellitus type 2”, “hydrocortisone”, “saliva”, “biomarker”, “depression”, and “periodontal disease”, following the PICO model. The Cochrane Collaboration tool was used to assess bias risk for randomized clinical studies, while the ROBINS-I tool was used for observational studies.

Adhering to PRISMA guidelines, 25 studies, comprising controlled interventions, pre-post studies, and observational/cohort or cross-sectional studies, were analyzed. We found a correlation between salivary cortisol levels and various health conditions. Elevated salivary cortisol was associated with increased disease severity in periodontitis, characterized by higher probing pocket depths and a greater plaque index. Patients with chronic periodontitis exhibited notably higher cortisol levels compared to healthy individuals, suggesting a link between stress and inflammatory responses in periodontal disease. Furthermore, salivary cortisol was identified as a valuable biomarker for detecting conditions, such as Cushing's syndrome and type 2 diabetes, with altered cortisol patterns indicative of disease progression. The findings highlighted the potential of salivary cortisol as a non-invasive diagnostic tool in assessing health status and managing related conditions.

Salivary cortisol serves as a crucial biomarker for the diagnosis and management of several health conditions, including Cushing's disease, diabetes, stress, depression, and periodontal disease. Its ease of measurement and reliability provide valuable insights into the Hypothalamic-pituitary-adrenal (HPA) axis, and the standardization of testing methods could enhance diagnostic accuracy. Continued research is essential to elucidate the interconnections among these conditions, which may inform future diagnostic and therapeutic strategies.