Angelika Buske-Kirschbaum

Free Cortisol Levels after Awakening: A Reliable Biological Marker for the Assessment of Adrenocortical Activity

In three independent studies, free cortisol levels after morning awakening were repeatedly measured in children, adults and elderly subjects (total n=152). Cortisol was assessed by sampling saliva at 10 or 15 minute intervals for 30-60 minutes, beginning at the time of awakening for two days (Study 1 and 2) or one (Study 3) day, respectively. In all three studies, free cortisol levels increased by 50-75% within the first 30 minutes after awakening in both sexes on all days. Premenopausal women consistently showed a stronger increase with a delayed peak after awakening compared to men on all days. In Study 2, there was a tendency for lower early morning free cortisol levels for women taking oral contraceptives (p=.10). Stability of the area under the curve (AUC) of the early morning free cortisol levels over the three (Study 1 and 2) or two (Study 3) days ranged between r=.39 and r=.67 (p<.001). Neither age, weight, nor smoking showed an effect on baseline or peak cortisol levels. Sleep duration, time of awakening and alcohol consumption also appeared to be unrelated to early morning free cortisol levels. From these data we conclude that in contrast to single assessments at fixed times, early morning cortisol levels can be a reliable biological marker for the individuals adrenocortical activity when measured repeatedly with strict reference to the time of awakening.

HPA axis responses to laboratory psychosocial stress in healthy elderly adults, younger adults, and children: impact of age and gender

Data from five independent studies were reanalyzed in order to investigate the impact of age and gender on HPA axis responses to an acute psychosocial laboratory stress task. The total sample consisted of 102 healthy subjects with 30 older adults (mean age: 67.3 y), 41 young adults (mean age: 23.5 y), and 31 children (mean age: 12.1 y). All participants were exposed to the Trier Social Stress Test (TSST). The stress protocol caused highly significant ACTH and total plasma cortisol responses in older and younger male and female adults (all p<0.0001) as well as salivary free cortisol responses in all six age and gender groups (all p<0.0001). Three-way ANOVAs for repeated measurement were applied to investigate the impact of age and gender on ACTH and cortisol responses. Results showed that the ACTH response to stress was higher in younger adults compared to older adults (main effect: p=0.009, interaction: p=0.06). Post hoc analyses revealed that there was no age effect in the subgroup of women (p=n.s.), while younger men had higher ACTH responses compared to older men (p=0.01). For total plasma cortisol, ANOVA results showed that the pattern of reactivity did not differ between age and gender groups (all interactional effects p=n.s.), although older females had hightened overall cortisol levels compared to the other groups, as proofed in post hoc analyses (all p<0.05). For free salivary cortisol, a significant main effect of gender (p=0.05) and an almost significant three-way-interaction (p=0.09) emerged. Post hoc analyses showed an elevated overall free salivary cortisol response in elderly men compared to elderly women (p=0.006), while no gender differences emerged in neither young adults nor children (both p=n.s.). In sum, the stressor induced significant HPA axis responses in all age and gender groups. The observed ACTH response patterns in young and elderly adults may suggest that a heightened hypothalamic drive in young men decreases with age, resulting in similar ACTH responses in elderly men and women. Alternative interpretations are also discussed. The data also supports the idea of a greater adrenal cortex sensitivity to ACTH signals in young females. Free salivary cortisol responses were elevated in elderly men compared to elderly women, an effect which cannot be explained by gender differences in perceived stress responses to the TSST. It can be speculated if corticosteroid binding globulin (CBG) and/or sex steroids are important modulators of these effects.

Attenuated free cortisol response to psychosocial stress in children with atopic dermatitis.

Objective Atopic dermatitis (AD) is an inflammatory skin disease characterized by a hyperactivity of the humoral immune system with an onset in infancy or early childhood. Although most of the research has focused on the pathophysiological role of the immune system in AD, the impact of endocrine signals in the pathology of AD has received only little attention. However, because the endocrine system may play a regulatory role in immune functioning, it might be of major interest to study endocrine reactivity in AD patients. The present two-part study investigated the relationship between adrenocortical stress response, heart rate response, and psychological parameters in children with AD. Method and Results In Study 1, a protocol for induction of psychosocial stress in children aged 8 to 14 years was evaluated. Healthy children (N = 16) were exposed to the Trier Social Stress Test for Children (TSST-C) that mainly consists of public speaking and mental arithmetic tasks in front of an audience. Salivary cortisol was measured 35, 15, and 1 minute before as well as 1, 10, 20, and 30 minutes after the stress; heart rate was monitored continuously. Results showed that the protocol induced a highly significant increase in free cortisol response (p<.001) and heart rate (p<.001). In Study 2, the TSST-C was applied to AD children (N = 15) and age- and sex-matched healthy controls (N = 15). All patients were in remission and medication-free for at least 3 weeks. Again, the stress test induced significant increases in cortisol and heart rate. However, the AD children showed a significantly blunted cortisol response to the stressor compared with the control group (p <.05). Heart rate responses were similar in both experimental groups. Neither subjective stress ratings nor personality traits were related to the blunted cortisol response. Conclusions These findings suggest that the adrenocortical response to stress is attenuated in atopic children. A hyporesponsive hypothalamus-pituitary-adrenal (HPA) axis might explain in part the stress-induced eruptions of AD symptoms.

Psychobiological Aspects of Atopic Dermatitis: An Overview

Atopic dermatitis (AD) is a chronic, pruritic inflammatory skin disease with increasing incidence characterized by eczematous inflammation of the skin, a chronically relapsing course and severe pruritus. In the last decade, there has been growing evidence indicating that psychological factors such as personality and stress may play an important role in the pathogenesis of AD. While there is only little consensus on an AD-specific personality profile and its etiological significance, a growing number of reports support the role of psychosocial stress in the onset and the course of AD symptomatology. However, although a close association between psychosocial stress and skin condition in AD patients has been demonstrated by several investigators, pathological models that integrate stress and its effect on atopy-relevant biological processes, e.g. immune processes, are still missing. This overview summarizes the role of immunological and psychological factors in AD pathogenesis and discusses potential psychobiological pathways of stress-related modulation of AD symptoms.

Is atopic disease a risk factor for attention-deficit/hyperactivity disorder? A systematic review.

To cite this article: Schmitt J, Buske‐Kirschbaum A, Roessner V. Is atopic disease a risk factor for attention‐deficit/hyperactivity disorder? A systematic review. Allergy 2010; 65: 1506–1524.

Endocrine and Immune Responses to Stress in Chronic Inflammatory Skin Disorders

Abstract: Atopy is a genetically and environmentally determined condition predisposing to different forms such as atopic dermatitis (AD) or allergic asthma (AA). Both AD and AA are considered to be multifactorial diseases; however, distinct immunologic abnormalities have been described that play a crucial role. There is growing evidence that immunoglobulin‐E hypersecretion and activation of the predominantly T‐helper‐2 (TH2)‐like T cell subset trigger allergic inflammatory processes and cause the disease to become chronic. In the present paper, data suggesting reduced hypothalamic‐pituitary‐adrenal (HPA) axis responsiveness in patients with AD and AA are summarized, and the potential etiologic significance of a hyporeactive HPA axis is discussed. We propose that because of defective HPA axis, immunoregulation under stressful conditions is ineffective in patients with atopic conditions, leading to aberrant immune responses and subsequent exacerbation of the disease. Further research into the role of the HPA axis in atopy may elucidate the cause of stress‐induced exacerbation of atopic symptoms and may be of clinical relevance.

Psychoendocrine and psychoneuroimmunological mechanisms in the comorbidity of atopic eczema and attention deficit/hyperactivity disorder

Epidemiological data indicate that atopic eczema (AE) in infancy significantly increases the risk for attention deficit/hyperactivity disorder (ADHD) in later life. The underlying pathophysiological mechanisms of this comorbidity are unknown. We propose that the release of inflammatory cytokines caused by the allergic inflammation and/or elevated levels of psychological stress as a result of the chronic disease interfere with the maturation of prefrontal cortex regions and neurotransmitter systems involved ADHD pathology. Alternatively, increased stress levels in ADHD patients may trigger AE via neuroimmunological mechanisms. In a third model, AE and ADHD may be viewed as two separate disorders with one or more shared risk factors (e.g., genetics, prenatal stress) that increase the susceptibility for both disorders leading to the co-occurrence of AE and ADHD. Future investigation of these three models may lead to a better understanding of the mechanisms underlying the observed comorbidity between AE and ADHD and further, to targeted interdisciplinary primary prevention and treatment strategies.

Endocrine stress responses in TH1-mediated chronic inflammatory skin disease (psoriasis vulgaris)—do they parallel stress-induced endocrine changes in TH2-mediated inflammatory dermatoses (atopic dermatitis)?

In previous research we reported attenuated responsiveness of the hypothalamus-pituitary-adrenal (HPA) axis and further, an increased reactivity of the sympathetic adrenomedullary (SAM) system to stress in patients suffering from atopic dermatitis (AD). AD is a chronic inflammatory skin disease mainly triggered by TH(2)-dependent inflammatory processes. The specific goal of the present study was to investigate whether altered HPA axis and SAM system responsiveness to stress can also be found in TH(1)-mediated inflammatory conditions. Patients with psoriasis (PSO; n=23), a TH(1)-mediated inflammatory (autoimmune) skin disease and healthy controls (n=25) were exposed to a standardized laboratory stressor (TSST) which mainly consists of a free speech and a mental arithmetic task in front of an audience. To investigate HPA axis and SAM system responsiveness, cortisol, ACTH, and catecholamines were determined before and after the stress test. In addition, cortisol levels after awakening and cortisol levels during the day (short diurnal profile) were determined. In order to test feedback sensitivity of the HPA axis, a dexamethasone (DEX) suppression test (0.5 mg) was performed. Analysis of cortisol and ACTH levels after the stress test yielded no significant differences between PSO subjects and controls indicating no altered HPA axis function in this patient group. Further, no between-group differences were found in cortisol levels after awakening or during the day (short diurnal profile). Additionally, no difference between PSO and healthy subjects in the feedback sensitivity of the system could be found (DEX test). However, PSO patients showed elevated epinephrine (F(3,102)=4.7; p<0.005) and norepinephrine (F(3,135)=2.7; p<0.05) levels in response to the stress test when compared to the controls. These findings suggest no altered HPA axis responsiveness, but increased reactivity of the SAM system in TH(1)-mediated chronic inflammatory skin disease.

Increased responsiveness of the hypothalamus- pituitary-adrenal (HPA) axis to stress in newborns with atopic disposition

In previous studies, atopic patients showed attenuated cortisol responses to psychosocial stress which is suggestive of a hyporeactive hypothalamus-pituitary-adrenal (HPA) axis in this patient group. Regarding the anti-inflammatory role of glucocorticoids, reduced responsiveness of the HPA axis under stress may be one potential explanation of stress-induced exacerbation of atopic symptoms. The present study evaluated whether hyporeactivity of the HPA axis is a feature related to the disposition of atopy rather than a consequence of an ongoing chronic allergic inflammatory process. Newborns with an atopic disposition (parental atopy; n=31) and without atopic disposition (no parental atopy; n=20) were recruited. To further assess atopic disposition, total IgE levels were determined in the cord blood of the neonates. Three days after birth, a blood sample was obtained by a heel prick which is part of a standard pediatric examination. Blood sampling by heel prick is well known to be a significant stressor resulting in activation of the HPA axis in newborns. Analysis of salivary cortisol indicated a significant increase of cortisol levels in the newborns after the stressor with a trend towards an elevated cortisol response in babies with a family history of atopy or with elevated levels of cord IgE (> or = 0.5 kU/l). Neonates with a positive parental atopic heritage and elevated cord IgE were found to show significantly elevated cortisol responses to the heel prick stress when compared to newborns without a parental atopic history and normal cord IgE values. Moreover, cord IgE levels were significantly correlated with basal cortisol levels and the cortisol response to the stressor. These findings suggest that atopic disposition in neonates is associated with altered responsiveness of the HPA axis to stress which may increase the vulnerability to develop manifestation of atopy in later life.

Influence of Stress during Pregnancy on HPA Activity and Neonatal Behavior

Abstract: Prenatal maternal stress has been shown to impair birth outcome and behavioral functioning in nonhuman primate offspring. Little is known about the effects of prenatal stress on behavioral development in humans. We assessed the effect of self‐reported prenatal stress on behavioral characteristics of 81 newborns using the Neonatal Behavioral Assessment Scale (NBAS). We suspected that high levels of perceived chronic stress during pregnancy may negatively affect the brain development of the fetus, reflected in poorer behavioral maturity and higher irritability. We found a poorer performance of newborns from high stressed mothers in the NBAS.