The association between heart rate variability and inflammatory markers in first-episode depressed patients with...

To investigate the associations between systemic inflammatory markers and heart rate variability (HRV) parameters across different levels of sleep disturbance in patients with first-episode depression.

A total of 76 patients with first-episode moderate-to-severe depression and 30 healthy controls were enrolled. Patients were stratified into three groups based on Pittsburgh Sleep Quality Index (PSQI) scores: low (LSD), moderate (MSD), and severe (SSD) sleep disturbance. Peripheral inflammatory markers and 24-hour HRV parameters were measured. Partial Spearman correlation analyses were performed adjusting for age, sex, BMI, smoking status, and alcohol consumption.

Significant group differences were observed in inflammatory markers (IL-6, IL-1β, TNF-α, CRP, ESR) and parasympathetic-related HRV indices (SDANN, SDNN, HF), with the SSD group exhibiting the most pronounced alterations (all FDR-adjusted p < 0.05). Moreover, significant negative correlations between inflammatory markers and HRV parameters were detected only in the SSD group after covariate adjustment.

The interaction between systemic inflammation and autonomic dysfunction appears to vary with sleep disturbance severity in depression. These findings highlight the importance of considering sleep disturbance stratification when evaluating physiological alterations in depressive disorders. Further studies are needed to clarify the underlying mechanisms and potential clinical implications of these associations.