Role of NR3C1 and SLC6A4 methylation in the HPA axis regulation in burnout

Quantifying the prevalence and predictors of burnout in emergency medical services personnel

INTRODUCTION

Recently, burnout has amassed considerable attention because of deleterious effects on workers and the work environment. Frequently, EMS clinicians find themselves prone to experiencing burnout, yet little is known about etiologies in this population.

OBJECTIVE

To estimate prevalence and predictors of burnout in EMS clinicians.

METHODS

This was a cross-sectional survey study of nine EMS agencies from North Carolina selected based on geography and population. Emergency medical technicians (EMTs), advanced EMTs, and paramedics were included. Emergency medical responders and air medical personnel were excluded if those positions were a primary occupational function. The Professional Quality of Life (ProQOL) Scale was used to assess burnout. Parametric and nonparametric testing was used to assess factors potentially affecting burnout. Factors significant in univariate analyses were included in a hierarchical linear regression model to determine unique predictors of burnout while controlling for confounders. The area under the curve (AUC) of the receiver operating characteristic (ROC) was used to determine model predictability.

RESULTS

A total of 686 EMS clinicians completed the survey. Overall, 57.3% (n = 393) were likely to have burnout. Of the 328 respondents who were likely to have burnout, 254 (77.4%) and 211 (75.1%) also were identified as likely to suffer from compassion fatigue or vicarious trauma, respectively. Overall, 152 (22.2%) were likely to suffer from all three stress disorders, 118 (56.5%) of which scored high enough to potentially produce immune system dysregulation. Prior suicidal thoughts ((sr2 = 0.042, p < 0.001), attempts (sr2 = 0.025, p < 0.001) or the presence of vicarious trauma (sr2 = 0.040, p < 0.001) accounted for 4.2%, 2.5%, and 4.0% of model variance, respectively. Years of field experience (sr2 = 0.035, p < 0.001) and credential level (sr2 = 0.011, p = 0.005) accounted for 4.6% of model variance. Finally, a respondent's experience or knowledge of debriefing (sr2 = 0.008, p = 0.023); experiencing adversity in childhood in the form of familial mental illness, depression, or suicide (sr2 = 0.009, p = 0.016); or the incarceration of a family member (sr2 = 0.010, p = 0.011) accounted for a combined 2.7% of model variance. Model predictability showed an AUCROC of 81.5%.

CONCLUSIONS

This study showed a nearly 60% prevalence of occupational burnout in the group of EMS clinicians surveyed, making burnout of considerable concern in this population. Further study is needed to address occupational factors that contribute to burnout in EMS clinicians.

Associations of SLC6A4 methylation with salivary cortisol, salivary alpha-amylase, and subjective stress in everyday life

Dysregulations of the hypothalamic-pituitary-adrenal (HPA) and sympatho-adrenal medullary (SAM) axis are associated with mental and somatic illness. However, there is lack of knowledge regarding the molecular mechanisms underlying these effects. Epigenetic states in the serotonin transporter gene (SLC6A4) were shown to be associated with stress in various forms. We hypothesized that levels of DNA methylation (DNAm) of SLC6A4 would be associated with altered SAM- and HPA regulation in daily life. N = 74 healthy persons participated in the study. An ecological momentary assessment (EMA) approach was used to assess indicators of stress in daily life. Each day included six concurrent assessments of saliva, to quantify cortisol (sCort; HPA axis) and alpha-amylase (sAA; SAM axis), and to assess self-reports on subjective stress. To assess SLC6A4 DNAm, peripheral blood was drawn and analyzed via bisulfite pyrosequencing. All data were assessed in two waves three months apart, each including two days of EMA and the assessment of SLC6A4 DNAm. Data were analyzed using multilevel models. On the between-person level, higher average levels of SLC6A4 DNAm were associated with higher average levels of sAA, but not with average levels of sCort. On the within-person level, higher levels of SLC6A4 DNAm were associated with lower levels of sAA and sCort. There were no associations of subjective stress with SLC6A4 DNAm. The results help to clarify the association between environmental stress and stress axes regulation, pointing towards an important role of differential within- and between-person effects of SLC6A4 DNAm, which might shape this association.

Associations of DNA methylation of HPA axis-related genes and neuroendocrine abnormalities in panic disorder

OBJECTIVE

The purpose of this study was to investigate the role of aberrant DNA methylation of hypothalamic-pituitary-adrenal (HPA) axis-related genes (CRHR1, CRHR2, CRH, FKBP5, HSP90AA1, NR3C1, and POMC) in panic disorder (PD) development. We investigated the correlation among gene methylation levels, adrenocorticotropic hormone (ACTH), cortisol, and PD severity in patients.

METHODS

We compared the methylation levels of HPA axis-related genes between 178 patients with PD and 184 healthy controls using MethylTarget. We then measured ACTH and cortisol levels using chemiluminescence. Disease severity was assessed using the Panic Disorder Severity Scale.

RESULTS

Compared with healthy controls, patients with PD displayed significantly higher levels of ACTH and cortisol, and significantly reduced methylation levels of CRHR1, FKBP5, HSP90AA1, and NR3C1 after correcting for multiple testing using the false discovery method. A significant positive correlation was observed between the methylation of CRHR1, CRHR2, and NR3C1 and ACTH levels in patients with PD, and methylation levels of CRHR1 and NR3C1 were significantly positively related to cortisol levels. In addition, a negative correlation was observed between PD severity and the methylation of CRH, CRHR1, CRHR2, and HSP90AA1.

CONCLUSION

Aberrant methylation of HPA axis-related genes may predict PD development and impact ACTH and cortisol levels.