Salivary Cortisol and Stress Levels in the Malayali Tribe of Thiruvannamalai: A Comparative In Vitro Study with Non-Tribal Groups

Introduction: Stress is a significant contributor to various health disorders, often linked to elevated cortisol levels mediated by the hypothalamic-pituitary-adrenal (HPA) axis. Salivary cortisol measurement is a reliable, non-invasive biomarker for assessing stress. This study aimed to compare salivary cortisol levels between the Malayali tribal population in Thiruvannamalai, Tamil Nadu and a non-tribal urban control group to evaluate stress differences and explore potential socio-environmental influences on cortisol levels. Methods: An in-vitro study was conducted between July and August 2024, involving 44 participants divided into two groups: Malayali tribes (n = 22) and non-tribal individuals (n = 22). Saliva samples were collected using the passive drool technique and analyzed using the Abbkine Human Cortisol ELISA Kit. Environmental and lifestyle factors, including dietary habits and occupational stress, were recorded to assess potential confounders. The Mann-Whitney U test was used for statistical analysis, with significance set at p<0.05. Results: The Malayali tribal group exhibited significantly higher mean salivary cortisol levels (13.44±2.15 µg/L) compared to the non-tribal group (8.73±1.85 µg/L) (p<0.05). Optical density values were also notably higher in the tribal group, reinforcing the elevated cortisol concentration. The ELISA assay demonstrated a non-linear relationship between optical density and cortisol concentration. The findings suggest that socio-economic challenges, environmental hardships and limited healthcare access may contribute to heightened stress levels in the tribal population. Conclusion: The study revealed significantly higher stress levels in the Malayali tribal population than in their non-tribal counterparts, likely driven by socio-environmental stressors. These results emphasize the urgent need for targeted interventions such as culturally adapted stress management programs, improved healthcare access and educational initiatives to mitigate chronic stress in tribal communities. Future research should explore broader sample sizes, longitudinal stress assessments and the role of cultural practices in influencing stress responses.