Leukocyte glucocorticoid receptor expression and immunoregulation in veterans with and without post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is associated with a dysregulation of the hypothalamus-pituitary-adrenal axis (HPA axis). In addition, there is evidence for altered glucocorticoid receptor (GR) expression and function in peripheral blood mononuclear cells. The aim of the present study was to differentiate between the effect of trauma exposure and PTSD on leukocyte GR expression and glucocorticoid immune regulation. Leukocyte GR binding characteristics and glucocorticoid sensitivity of immune activity, determined as the effect of dexamethasone (DEX) on in vitro cytokine release and T-cell proliferation, were compared between veterans with PTSD, traumatized veterans without PTSD and healthy controls. Leukocyte GR density was significantly lower in veterans with and without PTSD compared to healthy controls. DEX-induced inhibition of T-cell proliferation was significantly lower in PTSD compared to trauma and healthy controls. DEX-induced increase in lipopolysaccharide-stimulated interleukin-10 was less pronounced in traumatized veterans with and without PTSD compared to healthy controls. No group differences were observed in the effect of DEX on other cytokines or in baseline immune activity, except for lower tumor necrosis factor-alpha production in PTSD patients compared to healthy controls. The results suggest that trauma exposure is sufficient to induce changes in GR binding characteristics, whereas resistance of T-cell proliferation to DEX only occurs in PTSD. DEX resistance of in vitro immune activity was not a general phenomenon, but was restricted to specific immune functions.     

Twenty-four hour plasma cortisol and adrenocorticotropic hormone in Gulf War veterans: relationships to posttraumatic stress disorder and health symptoms.

BACKGROUND: We aim to characterize the baseline functioning of the hypothalamic-pituitary-adrenal (HPA) axis in Gulf War veterans (GWV) and examine the extent to which posttraumatic stress disorder (PTSD) and unexplained health symptoms-which commonly co-occur-have similar or different biological correlates. METHODS: Thirty-one GWV, 20 with current PTSD and 11 without current or lifetime PTSD, and 16 healthy nondeployed subjects not exposed to the Gulf War theater underwent medical and psychiatric examination followed by blood sampling every half-hour over 24 hours for the measurement of cortisol and adrenocorticotropic hormone (ACTH). RESULTS: Gulf War veterans without PTSD or another psychiatric disorder had significantly lower 24-hour plasma ACTH levels, a significantly higher cortisol:ACTH ratio, and no difference in cortisol levels compared to nondeployed subjects and to GWV with PTSD, controlling for body mass index (BMI). Among GWV, health symptoms (mood and cognitive symptoms) were positively associated with, and hyperarousal symptoms were negatively associated with, the cortisol:ACTH ratio. Additionally, the self-reported acute effects of pesticides and of pyridostigmine bromide during deployment were associated with lower ACTH levels, controlling for BMI and PTSD. CONCLUSIONS: The data provide evidence of HPA axis dysregulation in Gulf War veterans, which may be related to Gulf War deployment exposures. Despite the overlap of chronic unexplained health symptoms and PTSD in GWV, these symptom constellations appear to be biologically distinct.     

Enhanced cortisol suppression in response to dexamethasone administration in traumatized veterans with and without posttraumatic stress disorder

BACKGROUND: While enhanced cortisol suppression in response to dexamethasone is one of the most consistent biological findings in posttraumatic stress disorder (PTSD), the relative contribution of trauma exposure to this finding remains unclear. METHODS: Assessment of diurnal salivary cortisol levels and 1600 h salivary cortisol before and after oral administration of 0.5mg dexamethasone in veterans with PTSD, veterans without PTSD (trauma controls) and healthy controls. Assessment of 1600 h plasma cortisol, ACTH and corticotrophin binding globulin (CBG) in response to dexamethasone in PTSD patients and trauma controls. RESULTS: Both PTSD patients and trauma controls demonstrated significantly more salivary cortisol suppression compared to healthy controls. Salivary cortisol, plasma cortisol and ACTH suppression as well as CBG levels did not differ between PTSD patients and trauma controls. PTSD patients showed a reduced awakening cortisol response (ACR) compared to healthy controls that correlated significantly with PTSD symptoms. No significant differences were observed in ACR between PTSD patients and trauma controls. CONCLUSIONS: These data suggest that enhanced cortisol suppression to dexamethasone is related to trauma exposure and not specifically to PTSD. The correlation between the ACR and PTSD severity suggests that a flattened ACR may be a result of clinical symptoms.     

Differences in the response to the combined DEX-CRH test between PTSD patients with and without co-morbid depressive disorder

BACKGROUND: Neuroendocrine studies have shown profound alterations in HPA-axis regulation in posttraumatic stress disorder (PTSD). Based on baseline assessments and the response to dexamethasone, a hypothalamic overdrive with enhanced glucocorticoid feedback inhibition has been suggested. The dexamethasone-corticotrophin releasing hormone (DEX-CRH) test has shown to be a more sensitive test to assess HPA-axis dysregulation in major depression and therefore may provide a useful test tool to probe HPA-axis regulation in PTSD. METHODS: To evaluate the effect of PTSD on HPA-axis regulation, we compared the response to a DEX-CRH test between male veterans with PTSD (n=26) and male veterans, who had been exposed to similar traumatic events during their deployment, without PTSD (n=23). Patients and controls were matched on age, year and region of deployment. Additionally, we compared the response of PTSD patients with (n=13) and without co-morbid major depressive disorder (MDD) (n=13). RESULTS: No significant differences were observed in ACTH and cortisol response to the DEX-CRH test between patients and controls. PTSD patients with co-morbid MDD showed a significantly lower ACTH response compared to patients without co-morbid MDD. The response to the DEX-CRH test did not correlate with PTSD or depressive symptoms. CONCLUSION: The DEX-CRH test did not reveal HPA-axis abnormalities in PTSD patients as compared to trauma controls. PTSD patients with a co-morbid MDD showed an attenuated ACTH response compared to PTSD patients without co-morbid MDD, suggesting the presence of subgroups with different HPA-axis regulation within the PTSD group. Altered sensitivity of the CRH receptors at the pituitary or differences in AVP secretion might explain these differences in response.     

Neural correlates of associative learning and memory in veterans with posttraumatic stress disorder

Impaired attention and memory are symptoms frequently associated with posttraumatic stress disorder (PTSD). Although patients with PTSD frequently report memory difficulties and empirical research provides support for a memory deficit in PTSD, as of yet, no fMRI study has adequately investigated the neural correlates of learning and memory of neutral (i.e. not trauma related) material in patients with PTSD compared to controls. Twelve male veterans with PTSD, and twelve male veterans without PTSD, were recruited, and matched for age, region and year of deployment. Encoding and retrieval of 12 word-pair associates was assessed during fMRI in both experimental groups. Compared to controls veterans with PTSD revealed underactivation of the frontal cortex, and overactivation of the temporal cortex during the encoding phase. Retrieval of the paired associates resulted in underactivation of right frontal cortex, bilateral middle temporal gyri, and the left posterior hippocampus/parahippocampal gyrus in patients with PTSD. Deficits in memory performance in PTSD appear to be related to altered activity in fronto-temporal areas during both the encoding and retrieval phase of memory processing.     

HPA- and HPT-axis alterations in chronic posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) has been associated with dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis as well as of the hypothalamus-pituitary-thyroid (HPT) axis. Findings have not been consistent and may depend on methodological issues like controlling for relevant variables. This study examines the levels of six HPA and HPT-axis related hormones in civilian PTSD patients without psychotropic medication. In a cross sectional study, 39 chronic PTSD patients and 44 healthy volunteers were included. Psychometric instruments included SCID, SI-PTSD, IES-R and BDI. The plasma hormones levels assessed were cortisol, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S), prolactin, thyrotropin (TSH), and free thyroxin (fT4). Results showed that patients had significantly lower plasma cortisol, prolactin and TSH levels compared to the comparison group. The difference between TSH levels in patients and comparison subjects only emerged after controlling for relevant background variables. Furthermore, the severity of PTSD symptoms was negatively related to cortisol levels. Secondary analyses revealed no statistically significant effect of comorbid depression (26% of patients) on any of the hormone levels. Complex feedback mechanisms are likely to result in altered levels of stress related hormones in PTSD, and results depend on controlling for relevant variables. Further research with longitudinal designs is needed to find out whether these lower hormone levels are preexisting risk factors or consequence of trauma and whether these alterations are deleterious or adaptive.     

Dexamethasone suppression test in borderline personality disorder--effects of posttraumatic stress disorder

BACKGROUND: Divergent findings of hypothalamic-pituitary-adrenal (HPA) axis functioning in borderline personality disorder (BPD) may be caused by a different degree of comorbid posttraumatic stress disorder (PTSD), in which alterations of the HPA axis are well known. Here we investigate alterations of the HPA axis in BPD patients with and without comorbid PTSD compared to healthy controls. Considering previous findings current major depression (MDD) was taken into account as a confounding variable. METHODS: Apart from clinical assessment the 0.5 mg dexamethasone suppression test (DST) was performed in 21 female borderline patients and 23 healthy controls. RESULTS: Twelve BPD patients suffered from comorbid PTSD. Relative suppression (%) did not differ between healthy controls and the total BPD group, but BPD patients with comorbid PTSD showed increased suppression compared to those without. Comorbid MDD was not associated with suppression. CONCLUSIONS: Our results do not indicate a dysfunction of the HPA axis in BPD. However, comorbid PTSD seems to be associated with a relative hypersuppression in the 0.5 mg DST.     

Resting state functional connectivity of the anterior cingulate cortex in veterans with and without post‐traumatic stress disorder

Post‐traumatic stress disorder (PTSD) is an anxiety disorder that is associated with structural and functional alterations in several brain areas, including the anterior cingulate cortex (ACC). Here, we examine resting state functional connectivity of ACC subdivisions in PTSD, using a seed‐based approach. Resting state magnetic resonance images were obtained from male veterans with (n = 31) and without (n = 25) PTSD, and healthy male civilian controls (n = 25). Veterans with and without PTSD (combat controls) had reduced functional connectivity compared to healthy controls between the caudal ACC and the precentral gyrus, and between the perigenual ACC and the superior medial gyrus and middle temporal gyrus. Combat controls had increased connectivity between the rostral ACC and precentral/middle frontal gyrus compared to PTSD patients and healthy civilian controls. The resting state functional connectivity differences in the perigenual ACC network reported here indicate that veterans differ from healthy controls, potentially due to military training, deployment, and/or trauma exposure. In addition, specific alterations in the combat controls may potentially be related to resilience. These results underline the importance of distinguishing trauma‐exposed (combat) controls from healthy civilian controls when studying PTSD. Hum Brain Mapp, 36:99–109, 2015. © 2014 Wiley Periodicals, Inc.     

A combined dexamethasone/corticotropin-releasing hormone test in patients with chronic PTSD--first preliminary results

BACKGROUND: Reports about alterations of hypothalamic-pituitary-adrenocortical (HPA) function in patients with chronic posttraumatic stress disorder (PTSD) are inconsistent and controversial. More refined laboratory tests and subgrouping of PTSD patients might help to decrease variance of findings. METHODS: 14 subjects with chronic PTSD and 14 healthy controls were examined between 13:00 and 17:00 using a modified combined dexamethasone/CRH test (0.5 mg dexamethasone at 23:00, 100 microg CRH at 15:00). Plasma adenocorticotropic hormone (ACTH), cortisol and blood pressure were measured every 15 min from 14:45 until 17:00. RESULTS: No significant differences between patients and controls were found in the analyses of ACTH and cortisol levels, but a significantly elevated systolic and diastolic blood pressure in PTSD. Severity of depressive symptoms had no influence. However, explorative analyses showed that patients with a history of childhood traumatization had significantly higher post-dexamethasone-ACTH levels and a significantly lower diastolic blood pressure in comparison to patients without early trauma. CONCLUSIONS: In this first pilot study in a typical clinical sample of patients with chronic PTSD we found effects of severe adverse events in childhood on HPA axis regulation. Maybe, childhood traumatization could influence HPA axis findings in PTSD. Further research is needed, especially dose-response studies with different doses of dexamethasone in dexamethasone/CRH tests in PTSD.     

Salivary Oxytocin and Vasopressin Levels in Police Officers With and Without Post‐Traumatic Stress Disorder

Post‐traumatic stress disorder (PTSD) is characterised by symptoms associated with maladaptive fear and stress responses, as well as with social detachment. The neuropeptides oxytocin (OT) and arginine vasopressin (AVP) have been associated with both regulating fear and neuroendocrine stress responsiveness and social behaviour. However, there is only limited evidence for dysregulated peripheral OT and AVP levels in PTSD patients. The present study aimed to investigate basal salivary OT and AVP levels in trauma‐exposed male and female police officers with and without PTSD. Saliva samples were collected during rest and OT and AVP levels were determined using a radioimmunoassay. Men and women were analysed separately, having adjusted for differences in trauma history, and for hormonal contraception use in women. The results showed that male PTSD patients had lower basal salivary OT levels, and did not differ in AVP levels compared to male trauma‐exposed healthy controls after adjusting for childhood emotional abuse. There were no significant differences in basal salivary OT and AVP levels in women. Our findings indicate potential dysfunctioning of the OT system in male PTSD patients. Future studies are needed to replicate these findings and to further unravel the relationship between the OT and AVP systems, sex, trauma history and PTSD.