Self-reported sleep quality, physical activity and anxiety associated with heart rate variability in youth tiers derived via unsupervised machine learning

Anxiety, inadequate sleep, and insufficient physical activity are increasingly prevalent features of contemporary youth lifestyles and may collectively influence cardiac autonomic regulation. In this work, we aim to identify associations of these predictors with cardiac autonomic regulation via heart rate variability (HRV). Healthy participants aged 18–40 ( n = 321) without comorbidities were included. Participants completed batteries for International Physical Activity Questionnaire (IPAQ), The Beck Anxiety Inventory (BAI) and The Pittsburgh Sleep Quality Index (PSQI), followed by 5 min HRV. PCA identified HRV clusters, used to perform K means clustering to stratify the participants into lower (age < 22) and upper (age > 22) youth tier using R. Data was analyzed using SPSS 21. Significant main effects of IPAQ on SDNN and RMSSD (Pillai’s F = 1.969(9, 801), p < 0.05, ηp 2 = 0.02) and PSQI on SD1, SD2 (Pillai’s F = 2.90 (3, 175), p < 0.05, ηp 2 = 0.04) were observed. IPAQ*BAI*PSQI interaction had significant association with entropy in lower youth tier (Pillai’s F = 3.62 (2, 119), p < 0.05, ηp 2 = 0.05). IPAQ had significant main effects on HF, LF in lower youth tier males (F = 2.72 (6, 30), p < 0.05, ηp 2 = 0.35) ,while IPAQ*BAI*PSQI interaction has significant effects on entropy (F = 2.09 (10, 180), p < 0.05, ηp 2 = 0.10) in lower youth tier females, while PSQI had significant main effects on SD1, SD2 (F = 3.26 (3, 70), p = 0.03, ηp 2 = 0.12) in upper youth tier females. Psychobehavioral features show distinct cardiac autonomic regulation patterns in young adults.