Components of the diurnal cortisol cycle in relation to upper respiratory symptoms and perceived stress

Associations among Salivary Cortisol, Melatonin, Catecholamines, Sleep Quality and Stress in Women with Breast Cancer and Healthy Controls

Dysregulations in several biological systems in breast cancer patients have been reported, including abnormalities in endocrine and sympathetic nervous system indices, as well as psychological disturbances and sleep disorders. The purpose of this exploratory study was to compare women with breast cancer to healthy control women on measures of salivary cortisol, urinary catecholamines, overnight urinary melatonin, and self-reported sleep quality, symptoms of stress, depression, anxiety and mood disturbance, to determine if discernable patterns of dysregulations across systems were apparent. Thirty-three women were tested in each group, with an average age of approximately 52 years, primarily Caucasian and well-educated. Forty percent of the women with breast cancer had stage 2 disease and they were an average of 1.36 years post-diagnosis. Women with breast cancer had significantly higher levels of disturbance on all the psychological indices, but there were no differences between groups on any of the biological measures, with the exception that the control women had higher dopamine values than the participants with breast cancer. None of the psychological scores were correlated with the biological measures. These results are consistent with other studies of early-stage breast cancer and highlight the importance of considering disease characteristics when investigating endocrine and sympathetic nervous system functioning.

Assessing mid-trimester salivary cortisol levels across three consecutive days in pregnant women using an at-home collection protocol

The Pregnancy Outcomes and Community Health (POUCH) Study enrolled women in their 15th to 27th week of pregnancy from 52 prenatal clinics located in five communities. After the study began, an at-home protocol to measure maternal stress was added, which included collection of urine and saliva twice a day (waking = AM, bedtime = PM) for three consecutive days, and completion of a daily diary. The at-home protocol was in place for 2852 POUCH participants at enrollment, and 81.3% (n = 2318) consented and returned samples and diary. For these analyses, salivary cortisol was analysed in a subset of 846 women who delivered at term. Day-to-day correlation coefficients for AM cortisol (0.45-0.55) exceeded those for PM cortisol (0.31-0.43). Study diaries indicated that there was variation in the time interval between waking and sample collection. Analyses of discrete intervals showed the same awakening response pattern in cortisol levels that has been reported in studies with serial AM sampling. The adjusted mean AM cortisol (microg/dL) was 0.506 at 0-15 min post-waking, 0.544 at 16-30 min (P < 0.05), 0.582 at 31-60 min (P < 0.01), and 0.515 at >60 min post-waking. In addition, adjusted mean AM cortisol in samples collected at or before 9 a.m. was higher than that in samples collected after 9 a.m. (0.564 vs. 0.510 microg/dL, P < 0.01). Among working women, adjusted mean AM cortisol was higher on work days than non-work days (0.564 vs. 0.489 microg/dL, P < 0.01), and in multiparae compared with primiparae (0.551 vs. 0.502 microg/dL, P = 0.07). The parity effect was not evident in non-working women. The adjusted mean PM cortisol significantly increased as week of pregnancy at sampling increased, but was not significantly related to time of collection, work day and parity. Factors influencing AM and PM cortisol levels in pregnancy appear to differ. In studies of AM cortisol levels, it is important to gather data on time of sample collection, interval from waking to sample collection, parity and work.

Clinical correlates of DHEA associated with post-traumatic stress disorder

OBJECTIVE

Increased plasma dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) have been demonstrated in post-traumatic stress disorder (PTSD), but the documented beneficial effects of these steroids in enhancing mood and cognition, as well as neuroprotection, suggest their presence in PTSD may be associated with defensive rather than maladaptive effects.

METHOD

We, therefore, examined plasma DHEA, DHEAS, cortisol, and the DHEA/cortisol ratio in 40 male veterans with or without PTSD, and determined their relationships to PTSD symptom severity and symptom improvement.

RESULTS

The PTSD group showed significantly higher plasma DHEA and non-significantly higher DHEAS levels as well as a significantly lower cortisol/DHEA ratio, controlling for age. Regression analyses demonstrated that DHEA and DHEAS levels could be predicted by symptom improvement and coping, whereas the cortisol/DHEA ratio was predicted by severity of childhood trauma and current symptom severity.

CONCLUSION

That greater symptom improvement was related to DHEA levels may suggest for a role for these hormones in modulating recovery from PTSD.

Post-awakening cortisol secretion during basic military training

Salivary free cortisol concentrations in the first 30 min after awakening were assessed in 12 healthy army recruits at the beginning, middle and end of an 11-week intensive physical training course. To ensure strict adherence to protocol saliva collection was supervised and collected on each sampling day immediately on waking and again 15 and 30 min later. Self-rated psychological assessments of state levels of stress, arousal and fatigue were performed in the evening of each sampling day. A within-subjects repeated-measures analysis of participants who completed the course (12 of the original 20) showed a significant main effect of cortisol concentration across all three sampling points after awakening (F((2,22))=54.516, p<0.0001) and a significant main effect of weeks into the training course (F((3,33))=4.390, p=0.010). Further analysis of this effect of measurement-week revealed that at weeks 3 and 6 total cortisol secretion estimated by area under the curve was lower (F((3,33))=4.602, p=0.008) compared to the beginning and end of the course. Surprisingly self-reported stress, arousal and fatigue did not differ significantly across weeks, despite the large dropout rate (40%) and self-evident pressures of the course. We conclude that when controlling for many confounding variables, including participant adherence, post-awakening cortisol levels are sensitive to stressful challenge over a period of weeks.

Exercising in Environmental Extremes

Athletes, military personnel, fire fighters, mountaineers and astronauts may be required to perform in environmental extremes (e.g. heat, cold, high altitude and microgravity). Exercising in hot versus thermoneutral conditions (where core temperature is > or = 1 degrees C higher in hot conditions) augments circulating stress hormones, catecholamines and cytokines with associated increases in circulating leukocytes. Studies that have clamped the rise in core temperature during exercise (by exercising in cool water) demonstrate a large contribution of the rise in core temperature in the leukocytosis and cytokinaemia of exercise. However, with the exception of lowered stimulated lymphocyte responses after exercise in the heat, and in exertional heat illness patients (core temperature > 40 degrees C), recent laboratory studies show a limited effect of exercise in the heat on neutrophil function, monocyte function, natural killer cell activity and mucosal immunity. Therefore, most of the available evidence does not support the contention that exercising in the heat poses a greater threat to immune function (vs thermoneutral conditions). From a critical standpoint, due to ethical committee restrictions, most laboratory studies have evoked modest core temperature responses (< 39 degrees C). Given that core temperature during exercise in the field often exceeds levels associated with fever and hyperthermia (approximately 39.5 degrees C) field studies may provide an opportunity to determine the effects of severe heat stress on immunity. Field studies may also provide insight into the possible involvement of immune modulation in the aetiology of exertional heat stroke (core temperature > 40.6 degrees C) and identify the effects of acclimatisation on neuroendocrine and immune responses to exercise-heat stress. Laboratory studies can provide useful information by, for example, applying the thermal clamp model to examine the involvement of the rise in core temperature in the functional immune modifications associated with prolonged exercise. Studies investigating the effects of cold, high altitude and microgravity on immunity and infection incidence are often hindered by extraneous stressors (e.g. isolation). Nevertheless, the available evidence does not support the popular belief that short- or long-term cold exposure, with or without exercise, suppresses immunity and increases infection incidence. In fact, controlled laboratory studies indicate immuno-stimulatory effects of cold exposure. Although some evidence shows that ascent to high altitude increases infection incidence, clear conclusions are difficult to make because of some overlap with the symptoms of acute mountain sickness. Studies have reported suppressed cell-mediated immunity in mountaineers at high altitude and in astronauts after re-entering the normal gravity environment; however, the impact of this finding on resistance to infection remains unclear.

Psychological and stress hormone correlates in early life: a key to HPA-axis dysregulation and normalisation

Substantial recent research has focused on examining hormone indicators of psychosocial stress and on how relationships between stress and hormone changes might be linked to chronic illness. Particular attention has been paid to disease progression in cancer and HIV/AIDS. This focus has generated a plethora of research which has contributed both theoretically and clinically to the understanding of disease experience and the rate of disease progression. Measurement of salivary cortisol levels and diurnal variation has substantially advanced research methodology. Applying the unifying concept of allostasis and accumulated lifetime stress, this review attempts to assess the relevance of psychological and stress hormone correlates to disease resistance and health, through an examination of such correlates on the experience and outcomes of stress during childhood. Focus is on the role and importance of naturalistic social stress experiences such as school transition in healthy children, with emphasis on salivary cortisol as an endocrine marker of HPA-axis activation. It is argued that differing research perspectives offer valuable insight into the often assumed but largely unexplored links between early life experience and subsequent physical health outcomes in adulthood. Longitudinal studies incorporating measures of acute physical health outcome and of learning and memory are clearly needed.

The diurnal patterns of the adrenal steroids cortisol and dehydroepiandrosterone (DHEA) in relation to awakening

The steroid hormones, cortisol and dehydroepiandrosterone (DHEA) are the two main peripheral secretory products of the hypothalamic-pituitary-adrenal stress-neuroendocrine axis. The diurnal pattern of cortisol secretory activity has been well characterised. Various aspects of this pattern have been related to time of awakening, light exposure, psychological dimensions of affect, immune function and systemic health and well-being. DHEA is also an important adrenocortical steroid whose secretory activity has been related to immune function, psychological and health variables. The most pronounced feature of the diurnal cortisol cycle is a burst of secretory activity following awakening with a diurnal decline thereafter. We mapped DHEA secretory activity onto this cycle by measuring both steroids in saliva samples collected at distinct time points over the diurnal cycle, synchronised to awakening. Both steroids, particularly DHEA, showed stability across days of sample collection. A main distinction between cortisol and DHEA was that although DHEA was elevated in post-awakening samples compared with later in the day there was no evidence of an awakening stimulatory burst of DHEA secretory activity. Although DHEA in many respects paralleled cortisol secretory activity there was some dissociation; mean levels were positively but not tightly correlated. The secretory pattern of DHEA is very stable whereas cortisol secretory activity seems more sensitive to day-to-day variability.

The interaction of social network size and stressful life events predict delayed-type hypersensitivity among women with metastatic breast cancer

This study examined relationships between social support, stressful life events and antigen-specific cell-mediated immunity. Participants were 72 women with documented metastatic breast carcinoma, who completed self-report measures of social support and life stress. Immune response was assessed using the delayed type hypersensitivity (DTH) skin test. Number of positive antigens was significantly related to the interaction of social network size and stressful life events (p<0.05). Number of positive antigens was greater for women who had experienced a high frequency of stressful life events but who reported a larger network of support. However, social network size was inversely related to DTH response among women who had experienced fewer stressful life events. Average induration size was not significantly related to the quality of social support, life stress per se, or their interactions. The relationship between social network size and immune response in women with metastatic breast cancer depends on prior stressful life experience.

The awakening cortisol response: methodological issues and significance

The awakening cortisol response (ACR) is a discrete and distinctive part of the cortisol circadian cycle. In healthy adults salivary free cortisol concentrations increase by between 50 and 160% in the first 30 min immediately post-awakening (approximate average increase of 9 nmol/l, range 4-15 nmol/l, estimated to be equivalent to about three secretory episodes). However there are no agreed norms for the absolute concentrations of free cortisol in saliva either immediately post-awakening (range of 4.7-18.5 nmol/l) or 30 min post-awakening (range of 8.6-21.9 nmol/l). This review explores reasons for these discrepancies in normative data including confounding factors such as gender, age, awakening time, light and participant adherence. Although the physiological role of the ACR has not been clearly defined evidence is discussed that suggests it is under a distinct regulatory influence, different from the rest of the diurnal cortisol secretory cycle. Despite the difficulties associated with its measurement a range of studies have demonstrated an association between the ACR and psychosocial variables, stress and health. However it remains unclear whether positive affect and good health are consistently associated with larger or smaller awakening responses. It is early days in the search for the role and significance of the ACR. Its putative role in the regulation of physiological function across the day (e.g. the immune system) and its sensitivity to psychosocial variables make it a prime candidate as an intermediary linking mind and health.