| Background and objectiveSleep quality and depression has become a major issue for college students,particularly medical students.Medical students,as a distinct group of college students,not only have poor sleep,but they also have a higher prevalence rate than non-medical students and the general population,which may have negative consequences for their academic performance,physical and mental health,and overall quality of life.Sleep problems and depression have been demonstrated in previous research to impair an individual’s autonomic nervous system,which is reflected in heart rate variability.The primary symptom is that the autonomic nervous system’s overall activity,particularly the parasympathetic vagus nerve,is insufficient.Many researchers have linked autonomic nervous system and its functions with sleep and depression,and point out that the sleep quality in autonomic nervous and depression relationship plays a protective role.However,short-term heart rate variability recordings are mostly used in studies,while long-term heart rate variability recordings are rarely paid attention to and have not been verified in medical students.In addition,personality traits,especially Neuroticism,have long been pointed out to be closely related to various psychological problems.However,there are relatively few studies on personality traits and HRV,and the results of these studies vary greatly from study to study because of the differences in subjects and measuring tools.It is unknown whether HRV can predict personality traits and thus predict the physiological characteristics of personality trait dimensions,researches in this area remains to be explored.As a result,this study aims to investigate the relationship between sleep,depression,personality traits,and long-term heart rate variability in medical students,which will not only benefit future psychological counseling,intervention,and treatment effects,but will also enrich mental health detection methods.In this study,heart rate variability(24 hours,HRV24h/awake period,HRVwake/bedtime period,HRVsleep)was used as objective physiological indicators reflecting individual autonomic nervous system function,and sleep quality,depressive symptoms of medical students were used as indicators of their mental health.To investigate the relationship between sleep quality,depression,personality traits,and heart rate variability in medical students,to investigate the physiological characteristics of sleep,depression,and personality traits,and to provide empirical evidence for long-term heart rate variability application and research.MethodsSubjectsBetween October 2020 and November 2021,100 medical students(60 females and 40 males)were included in the study,based on preliminary screening and inclusion criteria.Research design and Procedure1.Participants filled in a questionnaire including the basic personal information,Pittsburgh Sleep Quality Index(PSQI),Beck Depression Inventory-Ⅱ(BDI-Ⅱ),NEO-Five Factor Inventory(NEO-FFI).2.Received training in the use of Holter.3.Completed 24-hour Holter ECG testing in school.Statistical analysisThe original data was double-entered using Excel 2016.Data processing and analysis were performed with SPSS Version 22.0 software.It mainly includes t test,one-way ANOVA,correlation analysis and regression analysis.Results(1)Medical students scored 7.45±7.87 in depression,5.12±2.63 in sleep quality,31.21±9.13 in neuroticism,40.06±6.70 in extroversion,40.28±5.56 in openness,43.60±4.23 in agreeableness and 41.32±5.82 in conscientiousness,respectively.(2)Gender comparison of HRV shows:Male medical students had significantly greater SDNN、LF and LF/HF than female medical students(SDNN:182.83±35.16 vs.164.17±36.25,LF:1431.97±632.80 vs.931.52±378.52,LF/HF:1.87±0.77 vs.1.33 ± 0.74,p<0.05).(3)The research on the relationship between heart rate variability(HRV)and sleep quality of medical students shows that:There was a marginal difference(p=0.055)in SDNN24h between the poor sleep quality group(162.61±38.38)and the good sleep quality group(177.16±34.98).In the comparison between HRV during awake period,there was a marginal difference(p=0.086)in LFwake between poor sleep quality(927.74±443.74)and good sleep quality(1034.85±414.48).Correlation analysis found that SDNN24h(r=-0.217)and LF24h(r=-0.234)were significantly negative correlated with sleep disturbance(a dimension of PSQI)(p<0.05),and SDNN24h had a significant positive predictive effect on sleep disturbance(a dimension of PSQI)(B=-0.003,t=-2.002,p<0.05).SDNNwake(r=-0.179,p=0.075)and LFwake(r=-0.187,p=0.062)during awake period were negatively correlated with sleep disturbance(a dimension of PSQI).SDNNsleep(r=-0.299)and LFsleep(r=-0.210)during bedtime period were significantly negative correlated with sleep disturbance(a dimension of PSQI)(p<0.05),and SDNNsleep had a significant positive predictive effect on sleep disturbance(a dimension of PSQI)(B=-0.004,t=-2.298,p<0.05).(4)The research on the relationship between heart rate variability(HRV)and depression among medical students showed that:there was no significant difference among the HRV indicators of depression symptom groups(p>0.05),and there was no significant correlation between HRV and depression(p>0.05).(5)The study on the relationship between heart rate variability(HRV)and the Big Five Personality of medical students showed that the SDNN24h was higher in the group with high conscientiousness(181.23 ±33.92)than in the group with low conscientiousness(163.78±37.51)(p<0.05).Correlation analysis found that there was a marginally negative correlation between SDNN24h and Neuroticism(r=-0.177,p=0.078).SDNN24h was significantly positively correlated with Extroversion(r=0.212,p<0.05)and Conscientiousness(r=0.310,p<0.01).RMSSDwake(r=-0.180,p=0.073)and pNN50wake(r=-0.196,p=0.051)during awake period showed marginally negative correlation with Openness.During bedtime period,SDNNsleep was marginal negatively correlated with Neuroticism(r=-0.190,p=0.058),and marginally positive correlated with Extraversion(r=0.184,p=0.067).SDNNsleep was significantly positive correlated with Conscientiousness(r=0.202,p<0.05).(6)The regression analysis of heart rate variability(HRV)on personality traits showed that SDNN24h had a significant positive predictive effect on Conscientiousness(B=0.047,t=2.999,p<0.05).Conclusions(1)Medical students’ sleep quality and depression need to be addressed and improved.(2)Medical students with poor sleep quality had reduced sympathetic nervous system activity,while those with a high Conscientiousness personality trait had higher sympathetic nervous system activity.And male medical students had higher sympathetic nervous system activity than female medical students.(3)SDNN and LF were related to the healthy sleep of medical students,among which SDNN24h and SDNNsleep were significant predictors.(4)The SDNN24h of medical students were significant predictors of Conscientiousness. |
