Psychological profile and heart rate variability in adults with self-perceived chronic stress: secondary analysis from a clinical trial
Background Chronic stress is a major public health issue linked to psychological vulnerability and autonomic dysregulation. While heart rate variability (HRV) is widely recognized as a biomarker of stress adaptability, few studies have characterized the psychophysiological profile of individuals who self-identify as chronically stressed. Understanding this relationship could clarify the integration between subjective perception and autonomic control mechanisms. Methods A cross-sectional study was conducted with 54 adults reporting chronic self-perceived stress for at least 6 months. Psychological assessment included validated Spanish versions of the Perceived Stress Scale (PSS-4), State–Trait Anxiety Inventory (STAI-6), Zung Self-Rating Depression Scale (SDS), Acceptance and Action Questionnaire (AAQ-II), UCLA Loneliness Scale, and Ten-Item Personality Inventory (TIPI). HRV was recorded using a Polar H10 sensor in 2 daily 5-min supine measurements (morning and evening) over 7 days. Time, frequency, and nonlinear-domain parameters were analyzed according to the Task Force standards. Results Participants presented high levels of anxiety, depression, and psychological inflexibility, together with moderately reduced HRV indices. No significant differences were found between levels of perceived stress. Higher conscientiousness showed modest positive correlations with SDNN, RMSSD, pNN50, and HRV triangular index, while sex differences were observed in frequency-domain HRV parameters. Overall, HRV was not clearly differentiated across perceived stress levels. Conclusion Adults with chronic self-perceived stress exhibit a psychophysiological pattern characterized by emotional vulnerability, cognitive overcontrol, and reduced autonomic flexibility. This state reflects latent regulatory vulnerability rather than an overt autonomic failure. HRV assessment combined with psychological profiling may enhance early identification of individuals at risk and support integrative approaches for stress regulation.