Sex Differences in Associations Between Resting-State Electroencephalography Indices and Short Form 36 Health Survey Subdomains in University Students: An Exploratory Study

OBJECTIVES This exploratory study investigated the associations between resting-state electroencephalography (EEG) indices and Short Form 36 Health Survey version 2 (SF-36v2) subdomains in university students to explore whether these relationships varied according to sex. By utilizing EEG indices as potential physiological indicators, this research explored the multifaceted connections between physiological data and quality of life. These findings provide preliminary insights into a physio-psychological perspective on the mental health of students, establishing an academic foundation for future research into sex-specific factors.METHODS A total of 208 university students participated in the study including 106 males and 102 females. Healthrelated quality of life was assessed using SF-36v2 across eight subdomains: physical functioning (PF), role physical (RP), role emotional (RE), social functioning (SF), bodily pain (BP), vitality (VT), mental health (MH), and general health (GH). Resting-state EEG was recorded, and three quantitative indices were calculated: theta/beta ratio (TBR), spectral edge frequency 90% (SEF-90), and beta/alpha ratio (BAR). Sex differences in EEG indices and SF-36v2 subdomain scores were examined using independent samples t-tests. Associations between EEG indices and SF-36v2 subdomains were examined using Pearson correlation analyses. Differences between sex-specific correlation coefficients were compared using Fisher’s r-to-z tests.RESULTS Among the EEG indices, BAR was significantly higher in male students than in female students (t = 2.738, <i>p</i> = 0.007), whereas no significant sex differences were observed in TBR or SEF-90. For the SF-36v2 subdomains, male students had significantly higher scores on PF and SF, whereas female students had significantly higher scores on BP, VT, MH, and GH. No significant sex differences were observed in RP or RE. In the total sample, nominally significant positive correlations were observed between TBR and SF (r = 0.163, <i>p</i> = 0.019) and between BAR and SF (r = 0.175, <i>p</i> = 0.011); however, neither association remained significant after Bonferroni correction. Nominal sex differences in correlation coefficients were observed for TBR-PF (Fisher’s z = 2.854, unadjusted <i>p</i> = 0.0043), TBR-RP (Fisher’s z = 3.163, unadjusted <i>p</i> = 0.0016), and TBR-RE (Fisher’s z = 2.091, unadjusted <i>p</i> = 0.0365). After Bonferroni correction for 24 comparisons, only the sex difference in the TBR-RP correlation remained statistically significant (adjusted <i>p</i> = 0.038).CONCLUSIONS Associations between resting-state EEG indices and health-related quality of life were not consistent across SF-36v2 subdomains. After multiple-comparison correction, evidence of a sex difference was limited to the TBRRP correlation. Reflecting the exploratory nature of this study, this finding should not be overinterpretedas evidence that TBR directly reflects neurophysiological resilience or a sex-specific mechanism. Because of the cross-sectional design and unmeasured confounding factors, causal relationships cannot be established. Further adequately powered longitudinal studies with systematic covariate controls are required to clarify the reproducibility and practical implications of these preliminary findings.