Background: Past research has sought to explore the correlation between obstructive sleep apnea (OSA) and arousal patterns, characterized by the cyclic alternating pattern (CAP). However, findings have been inconclusive, and are possibly influenced by the presence of accompanying comorbidities such as major depressive disorder (MDD). This study investigates the heart rate variability (HRV) during CAP and non-CAP events in OSA co-occurring with MDD, to provide a more accurate understanding of the individual's pathophysiological state during sleep.
Objective: To identify the HRV measurements that predict depression in OSA patients during CAP and non-CAP events, shedding light on potential biomarkers for enhanced clinical assessment.
Methods: Patient data were obtained from the American Center for Psychiatry and Neurology in Abu Dhabi, UAE. The cohort comprised 26 individuals with OSA and 19 individuals with OSA and MDD. HRV parameters in the frequency and time domains, and non-linear components during CAP and non-CAP events were evaluated using nonparametric Student's t-test, Wilcoxon signed-rank test, and stepwise regression.
Findings: Distinctive HRV patterns during CAP and non-CAP episodes were associated with depression in OSA patients. Of these, sample entropy (SampEn) was significantly higher in OSA patients with depression during CAP and non-CAP analysis. Moreover, Beta power (β), normalized very low frequency (nVLF), and SampEn were significant predictors of depression during CAP events (AUC = 0.81, p < 0.05). Similarly, Total Power, vLF, and SampEn were found to be significant predictors ( AUC = 0.77, p < 0.05) during non-CAP events.
Conclusion: The discovery of sample entropy as a predictive marker of depression in OSA during CAP and non-CAP states provides important information for risk assessment This highlights the significance of integrating HRV analysis into the clinical evaluation of depression in OSA patients and may facilitate the development of more tailored and efficient healthcare interventions for this population.