Increase In Salivary Cortisol Levels Research Articles

Reduced neural responses to pleasant odor stimuli after acute psychological stress is associated with cortisol reactivity

Acute stress alters olfactory perception. However, little is known about the neural processing of olfactory stimuli after acute stress exposure and the role of cortisol in such an effect. Here, we used an event-related olfactory fMRI paradigm to investigate brain responses to odors of different valence (unpleasant, pleasant, or neutral) in healthy young adults following an acute stress (Trier Social Stress Test, TSST) induction (N = 22) or a non-stressful resting condition (N = 22). We obtained the odor pleasantness, intensity, and familiarity ratings after the acute stress induction or resting condition. We also measured the participants' perceived stress and salivary cortisol at four time points during the procedure. We found a stress-related decrease in brain activation in response to the pleasant, but not to the neutral or unpleasant odor stimuli in the right piriform cortex extending to the right amygdala, the right orbitofrontal cortex, and the right insula. In addition, activation of clusters within the regions of interest were negatively associated with individual baseline-to-peak increase in salivary cortisol levels after stress. We also found increased functional connectivity between the right piriform cortex and the right insula after stress when the pleasant odor was presented. The strength of the connectivity was positively correlated with increased perceived stress levels immediately after stress exposure. These results provide novel evidence for the effects of acute stress in attenuating the neural processing of a pleasant olfactory stimulus. Together with previous findings, the effect of acute stress on human olfactory perception appears to depend on both the valence and the concentration (e.g., peri-threshold or suprathreshold levels) of odor stimuli.

The effects of momentary loneliness and COVID-19 stressors on hypothalamic–pituitary adrenal (HPA) axis functioning: A lockdown stage changes the association between loneliness and salivary cortisol

The COVID-19 pandemic can be characterized as a chronic stressor affecting the hypothalamic–pituitary–adrenal (HPA) axis, indexed by glucocorticoids (e.g., cortisol). We investigated whether salivary cortisol level is increased during a lockdown and whether a lockdown condition affects the association between loneliness, specific COVID-19 related stressors and salivary cortisol level. We conducted a smartphone-based ecological momentary assessment (EMA) study with 280 participants in Germany who experienced at least mild loneliness and distress amid COVID-19 from August 2020 to March 2021. We measured their momentary loneliness and COVID-related stressors including worries, information seeking behaviors and feelings of restriction during “no-lockdown” or “lockdown” stages amid COVID-19. Their salivary cortisol was measured 4 times on the last day of a 7-day EMA study. We found a significant increase in salivary cortisol levels during lockdown compared to no-lockdown. Lockdown stage was found to moderate the relationship between momentary loneliness and salivary cortisol level, i.e., loneliness was positively related to cortisol level specifically during lockdown. Mechanisms explaining the effect of forced social isolation on the association between loneliness and salivary cortisol need to be investigated in future studies.

Repeated separations between a future guide dog and its foster family modify stress-related indicators and affect dog’s focus

In some guide dog organisations, future guide dogs for blind individuals are required to undergo separation from their foster family from Monday to Friday as part of their training. These separations and the constantly changing environment may induce stress, thus impacting the welfare of these dogs and their performance. The aim of this study was therefore to evaluate this stress through physiological and behavioural measures. The results showed a significant increase in salivary cortisol levels at the time of separation (GLMM; DF = 2; F = 10.31; p < 0.0001). Additionally, the dogs were more passive on Friday than on other days (GLMM; DF = 2; F = 7.53; p = 0.0090), and “head movements” were expressed less frequently on Fridays (GLMM; DF = 2; F = 5.12; p = 0.0141). Performance increased across weeks, despite a lower “focused” score on Mondays (GLMM; DF = 2; F = 4.39; p = 0.0243). These results showed both adaptation to life in the kennel and that the dogs need to readapt to the situation each week. The increase in serotonin levels during the 3 weeks of testing (GLMM; DF = 2; F = 4.87; p = 0.0224) may also indicate that the dogs can adapt to the kennel environment. Therefore, this study questions the relevance of noncontinuous training programmes. In future research, it would be interesting to compare these results with those of a group of dogs staying at school on weekends.

Effect of Photobiomodulation on Salivary Cortisol, Masticatory Muscle Strength, and Clinical Signs in Children with Sleep Bruxism: A Randomized Controlled Trial.

Background: The diagnosis of sleep bruxism (SB) in children is difficult due to the lack of a polysomnographic protocol for this population. Moreover, the gold standard treatment [occlusal splint (OS) therapy] has limitations, as adequate use depends on the child's cooperation. The etiology of SB may include stress factors. Salivary cortisol is a biomarker used as a noninvasive method to evaluate the response to stress. Besides physiological aspects, it is also important to investigate morphological aspects, such as masticatory muscle strength. The aim of the present study was to determine the occurrence of bite marks on the buccal mucosa in children as a complementary sign for the diagnosis of SB and investigate and the effectiveness of photobiomodulation as an alternative treatment for this condition. Methods: Seventy-six children 6-12 years of age were divided into four groups: G1-with SB and submitted to laser therapy over acupuncture points (λ = 786.94 nm, 20 sec per point, fluency = 33.5 Jcm2, energy = 1 J, number of points = 12); G2-with SB, use of OS, G3-with SB and submitted to sham laser therapy; and G4-control group without SB. Clinical signs (bite marks on buccal mucosa and headaches), bite force (BF), and salivary cortisol (biomarker of stress) were evaluated before and after treatment. Statistical analysis involved the Kolmogorov-Smirnov, Shapiro-Wilk, and analysis of variance (ANOVA) tests. Results: Bite marks on the buccal mucosa were significantly associated with SB (p < 0.001). A statistically significant difference was found between the frequency of children with headache before and after treatment in G1 (p = 0.0005) and G2 (p = 0.0001), with no significant differences between the two groups (G1 and G2). The children in G1 had lower BF on both sides compared to the other groups. In the intragroup analysis after treatment, all groups exhibited an increase in salivary cortisol levels. Conclusions: Bite marks on the buccal mucosa can be used as a complementary sign for the clinical diagnosis of SB. Children with SB responded well to photobiomodulation therapy, as evidenced by the reduction in BF and reports of headache.

Salivary cortisol levels in patients with potentially malignant oral disorders and oral mucosal cancer: a case-control study.

The relationship between salivary cortisol secretion and the presence of cancer in the oral cavity has not been completely clarified. Due to this, we proposed carrying out a study to determine salivary cortisol levels in patients with potentially malignant disorders (PMD), oral squamous cell carcinoma (OSCC) and healthy individuals. Cross-sectional case-control study, among 80 patients seen at the Faculty of Dentistry of the National University of Rosario, Argentina, between January 2018 and April 2020. 40 cases represented by Leukoplakia, Lichen, Erythroplakia and SCC and 40 controls were included. Smoking habit and alcohol consumption were included. The presence of stress was determined. Morning salivary cortisol levels were measured with the Roche electrochemiluminescence method (Traceability: St by ID-MS). Patients with SCC presented elevated salivary cortisol values. Individuals with stage III tumors showed levels higher than 8.74 ng/ml in all cases. A significant association between cortisol levels and stress was detected in patients in the control group (p<0.005) and in individuals with PMD (p=0.009). This association was not significant in patients with SCC (p=0.999). After applying the logistic regression method, when adjusting odds ratios according to tobacco and alcohol consumption and the presence of stress, the association between cortisol levels and presence of stress was highly significant (p<0.001). The possibility of presenting undetectable cortisol results was 94% lower in patients with stress. The increase in salivary cortisol levels in patients with PMD and SCC, is related to stress conditions, being able to generate alterations tending to immunosuppression of the cellular microenvironment.

Association Between Anxiety, Depression, and Salivary Cortisol Levels in Patients with Recurrent Aphthous Stomatitis.

Recurrent aphthous stomatitis (RAS) is the most common ulcerative disease of the oral mucosa that commonly affects the general population. The objective of this study was to conduct a research in assesing the relationship between psychological disorders including anxiety, depression and salivary cortisol levels in patients with RAS. Thirty-nine patients suffering from minor RAS were enrolled in the study after obtaining an informed consent. The control group consisted of 25 age and gender matched healthy individuals. All subjects were evaluated by using both psychological tests (Hamilton's anxiety rating scale [HARS] and Hamilton's depression rating scale [HDRS]) and physiological testing instrument (salivary cortisol level). While no statistical difference was found between the patients with RAS and controls for both salivary cortisol levels and anxiety, there was statisticaly significant difference between the groups for depression. There was no significant increase in salivary cortisol levels in patients with active disease when compared to the healthy subjects. But we found that depression scale values were significantly higher in patients with RAS.

Influence of the noradrenergic system on the formation of intrusive memories in women: an experimental approach with a trauma film paradigm.

Intrusive memories of traumatic events are a core feature of post-traumatic stress disorder but little is known about the neurobiological formation of intrusions. The aim of this study was to determine whether the activity of the noradrenergic system during an intrusion-inducing stressor would influence subsequent intrusive memories. We conducted an experimental, double-blind, placebo-controlled study in 118 healthy women. Participants received a single dose of either 10 mg yohimbine, stimulating noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic activity, or placebo. Subsequently, they watched an established trauma film which induced intrusions. The number of consecutive intrusions resulting from the trauma film, the vividness of the intrusions, and the degree of distress evoked by the intrusions were assessed during the following 4 days. Salivary cortisol and α-amylase were collected before and after the trauma film. A significant time × treatment interaction for the number of intrusions and the vividness of intrusions indicated a different time course of intrusions depending on treatment. Post-hoc tests revealed a delayed decrease of intrusions and a delayed decrease of intrusion vividness after the trauma film in the yohimbine group compared with the clonidine and placebo groups. Furthermore, after yohimbine administration, a significant increase in salivary cortisol levels was observed during the trauma film. Our findings indicate that pharmacological activation of the noradrenergic system during an emotionally negative event makes an impact on consecutive intrusive memories and their vividness in healthy women. The noradrenergic system seems to be involved in the formation of intrusive memories.

Fermented Milk Containing Lactobacillus casei Strain Shirota Preserves the Diversity of the Gut Microbiota and Relieves Abdominal Dysfunction in Healthy Medical Students Exposed to Academic Stress.

Stress-induced abdominal dysfunction is an attractive target for probiotics. To investigate the effects of the probiotic Lactobacillus casei strain Shirota on abdominal dysfunction, a double-blind, placebo-controlled trial was conducted with healthy medical students undertaking an authorized nationwide examination for academic advancement. For 8 weeks, until the day before the examination, 23 and 24 subjects consumed an L. casei strain Shirota-fermented milk and a placebo milk daily, respectively. In addition to assessments of abdominal symptoms, psychophysical state, and salivary stress markers, gene expression changes in peripheral blood leukocytes and composition of the gut microbiota were analyzed using DNA microarray analysis and 16S rRNA gene amplicon sequence analysis, respectively, before and after the intervention. Stress-induced increases in a visual analog scale measuring feelings of stress, the total score of abdominal dysfunction, and the number of genes with changes in expression of more than 2-fold in leukocytes were significantly suppressed in the L. casei strain Shirota group compared with those in the placebo group. A significant increase in salivary cortisol levels before the examination was observed only in the placebo group. The administration of L. casei strain Shirota, but not placebo, significantly reduced gastrointestinal symptoms. Moreover, 16S rRNA gene amplicon sequencing demonstrated that the L. casei strain Shirota group had significantly higher numbers of species, a marker of the alpha-diversity index, in their gut microbiota and a significantly lower percentage of Bacteroidaceae than the placebo group. Our findings indicate that the daily consumption of probiotics, such as L. casei strain Shirota, preserves the diversity of the gut microbiota and may relieve stress-associated responses of abdominal dysfunction in healthy subjects exposed to stressful situations. A novel clinical trial was conducted with healthy medical students under examination stress conditions. It was demonstrated that the daily consumption of lactic acid bacteria provided health benefits to prevent the onset of stress-associated abdominal symptoms and a good change of gut microbiota in healthy medical students.

Probiotic Lactobacillus casei strain Shirota relieves stress‐associated symptoms by modulating the gut–brain interaction in human and animal models

This study aimed to examine the effects of Lactobacillus casei strain Shirota (LcS) on gut-brain interactions under stressful conditions. Three double-blind, placebo-controlled trials were conducted to examine the effects of LcS on psychological and physiological stress responses in healthy medical students under academic examination stress. Subjects received LcS-fermented milk or placebo daily for 8weeks prior to taking a national standardized examination. Subjective anxiety scores, salivary cortisol levels, and the presence of physical symptoms during the intervention were pooled and analyzed. In the animal study, rats were given feed with or without LcS for 2weeks, then submitted to water avoidance stress (WAS). Plasma corticosterone concentration and the expression of cFos and corticotropin releasing factor (CRF) in the paraventricular nucleus (PVN) were measured immediately after WAS. In an electrophysiological study, gastric vagal afferent nerve activity was monitored after intragastric administration of LcS to urethane-anesthetized rats. Academic stress-induced increases in salivary cortisol levels and the incidence rate of physical symptoms were significantly suppressed in the LcS group compared with the placebo group. In rats pretreated with LcS, WAS-induced increases in plasma corticosterone were significantly suppressed, and the number of CRF-expressing cells in the PVN was reduced. Intragastric administration of LcS stimulated gastric vagal afferent activity in a dose-dependent manner. These findings suggest that LcS may prevent hypersecretion of cortisol and physical symptoms under stressful conditions, possibly through vagal afferent signaling to the brain and reduced stress reactivity in the PVN.

Fear and physiological arousal during a virtual height challenge—effects in patients with acrophobia and healthy controls

Virtual reality (VR) exposure therapy is becoming increasingly established, but the mode of action is not well understood. One potential efficacy factor might be physiological arousal.To investigate arousal during VR exposure, we exposed 40 patients with acrophobia and 40 matched healthy controls to a VR height challenge and assessed subjective (fear ratings) and physiological (heart rate, skin conductance level, salivary cortisol) fear reactions.Patients experienced a significant increase of subjective fear, heart rate and skin conductance level. Unexpectedly, controls, who reported no subjective fear, also showed an increase in heart rate and skin conductance. There was no increase in salivary cortisol levels in either group.Physiological arousal in acrophobic patients, in contrast to subjective fear, might not be stronger than that of controls confronted with height cues in VR, indicating marked discordance across symptom domains. The lack of a cortisol response in a clearly stressful paradigm warrants further study.

Stress induced by the socially evaluated cold-pressor test cause equivalent deficiencies of sensory gating in male subjects with schizophrenia and healthy controls

It is known that patients with schizophrenia show a deficiency in the prepulse inhibition reflex (PPI). These patients display abnormalities in autonomic nervous system and hypothalamic–pituitary–adrenal function and may have an altered sensitivity to stress. To date, no studies have been carried out to determine the effect of acute stress on the PPI. We investigated whether there was a differential response in reactivity to acute stress caused by the socially evaluated cold-pressor test (SECPT) in a sample of 58 chronic male patients with schizophrenia and 28 healthy control subjects. PPI, salivary cortisol and heart rate (HR) were measured. The patients were evaluated in two sessions (with and without the SECPT) 72h apart and basal measurements were carried out and 30min post-startle probe. We found an increase in salivary cortisol levels and the HR with SECPT condition in both groups and a significantly lower PPI% in patients with schizophrenia. The most relevant findings of this study are that the impairment of the PPI is increased by stress. Stress-induced increase in cortisol in both groups, mainly in healthy control group which allows us to hypothesize that at least such deterioration may be due to the hypercortisolemia caused by the SECPT.

Cortisol and alpha-amylase as stress response indicators during pre-hospital emergency medicine training with repetitive high-fidelity simulation and scenarios with standardized patients.

BackgroundIn emergency medicine, the benefits of high-fidelity simulation (SIM) are widely accepted and standardized patients (SP) are known to mimic real patients accurately. However, only limited data are available concerning physicians’ stress markers within these training environments.The aim of this pilot study was to investigate repetitive stress among healthcare professionals in simulated pre-hospital emergency scenarios using either SIM or SPs.MethodsTeams with one emergency medical services (EMS) physician and two paramedics completed three SIM scenarios and two SP scenarios consecutively. To evaluate stress, salivary cortisol and alpha-amylase were measured in saliva samples taken before, during and after the scenarios.ResultsA total of 14 EMS physicians (29% female; mean age: 36.8 ± 5.0 years; mean duration of EMS-experience: 9.1 ± 5.8 years) and 27 paramedics (11% female; age: 30.9 ± 6.9 years; EMS experience: 8.1 ± 6.0 years) completed the study. Alpha-amylase and cortisol levels did not differ significantly between the two professions. Cortisol values showed a gradual and statistically significant reduction over time but little change was observed in response to each scenario. In contrast, alpha-amylase activity increased significantly in response to every SIM and SP scenario, but there was no clear trend towards an overall increase or decrease over time.ConclusionIncreases in salivary alpha-amylase activity suggest that both SIM and SP training produce stress among emergency healthcare professionals. Corresponding increases in salivary cortisol levels were not observed. Among physicians in the emergency setting, it appears that alpha-amylase provides a more sensitive measure of stress levels than cortisol.

Evaluation of stress and pain in young children with cerebral palsy during early developmental intervention programs: a descriptive study.

The aim of this study was to use the Face, Legs, Activity, Cry, Consolability Scale; salivary cortisol levels; and withdrawal reflex thresholds to assess pain, stress, and pain sensitivity in young children with cerebral palsy during early developmental intervention programs. A total of 40 children with cerebral palsy (age range, 1-4 yrs) participated in the early intervention programs, which included neurodevelopmental treatment, neuromuscular electrical stimulation, occupational therapy, head acupuncture, and Chinese traditional manipulation five times per week for 3 wks. The Face, Legs, Activity, Cry, Consolability Scale was applied during the course of each treatment, and salivary cortisol samples were obtained from each child 10 mins before and 10 mins after each treatment. Withdrawal reflex thresholds were assessed via mechanical stimulation of the foot with von Frey hairs. All treatment programs caused some degree of pain. In descending order, the extents of the pain caused by each treatment were head acupuncture, neurodevelopmental treatment, neuromuscular electrical stimulation, Chinese traditional manipulation, and occupational therapy. There were statistically significant increases in salivary cortisol levels after the head acupuncture (P < 0.001), neurodevelopmental treatment (P < 0.001), neuromuscular electrical stimulation (P < 0.001), and Chinese traditional manipulation (P < 0.001) treatments. No significant changes were found in the withdrawal reflex thresholds during the study (P > 0.05). The results of this study demonstrate that early developmental intervention programs cause pain and stress in young children with cerebral palsy.

Changes in salivary hormones, immunoglobulin A, and C-reactive protein in response to ultra-endurance exercises.

The aim of the study was to determine the influence of the exercise duration on the changes in salivary stress markers in response to ultra-endurance exercises. The study was developed in 2 ultra-endurance exercise tests: the Ultra-trail Serra de Tramuntana (UTST), a 104 km ultra-marathon competition (n = 64) and the 25 km Cabrera Open Water Race (COWR) (n = 43). Participants in the COWR completed the 25 km at a constant pace of 3 km/h (3K group) or 2.5 km /h (2.5K group). Saliva samples were taken before and after the exercises. Salivary flow rate as well as cortisol, testosterone, C-reactive protein (CRP), and immunoglobulin A (IgA) levels were measured. Salivary flow rate decreased after the UTST but increased after the COWR. The UTST induced significant increases in cortisol and CRP levels and decreases in testosterone and IgA levels. Furthermore, a negative correlation was found between the time the athletes took to complete the exercise and the changes in salivary cortisol. After the COWR, higher increases in salivary cortisol levels were observed in the 3K group than in the 2.5K group. A significant effect of exercise decreasing testosterone and IgA levels was observed in both groups. No changes in the CRP levels were observed during the COWR. In conclusion, shorter times to complete the ultra-endurance exercise were associated with higher increases in cortisol. However, no relationships were found between the time to complete the exercises and the changes in testosterone, CRP, and IgA levels.

Morning and Afternoon Bouts of Exercise Result in the Same Physiological Stress Response

Circulating cortisol levels increase in response to physiological stress beyond levels observed in normal diurnal patterns. To compare the physiological stress response after a signal bout of exercise in the morning versus the afternoon, participants were assigned to three groups: morning exercise (n=8), afternoon exercise (n=7), or no exercise (n=7). Morning and afternoon exercise groups participated in 15 minutes of training, alternating resistance and cardiovascular activities, at 07:00 or 15:00 hours, respectively. Salivary cortisol samples were taken from all participants throughout the day. Pulse and blood pressure were recorded to ensure consistency of exertion during exercise bouts. Mean peak cortisol concentrations following exercise occurred 30–45 minutes after completion of exercise (1.16 ± 0.237 μg/dL and 0.651 ± 0.177 μg/dL, morning and afternoon exercise groups, respectively). There was a significant increase in salivary cortisol levels, as indicated by increase in area under the curve (AUC), between the no exercise and the morning exercise groups (p=0.0009), with cortisol levels reaching values almost twice the magnitude in the morning exercise group. Time of day did not affect the physiological stress response to exercise, as there was no significant difference in salivary cortisol AUC. V. Dautermann and N. Mantina were supported by the Beloit College Biomedical Scholars Program.

Increased morning salivary cortisol levels in older adults with nonamnestic and multidomain mild cognitive impairment

Exposure to elevated glucocorticoid levels has a detrimental impact on cognitive function. In the present study, elderly individuals were classified according to their cognitive status to (i) cognitively healthy; (ii) amnestic; (iii) nonamnestic; or (iv) multidomain, with an extensive cognitive profiling. Salivary cortisol samples were taken at awakening, evening and night. We report that, compared to cognitively normal control individuals, subjects with nonamnestic or multidomain mild cognitive impairment profiles show increased salivary cortisol levels, immediately after awakening, but not in the evening or at night. Importantly, individuals with amnestic mild cognitive impairment did not show this increase in salivary cortisol levels. We also found that higher morning cortisol levels were associated with a lower global cognitive state, as well as poorer score in executive function and visuoconstructive praxes, verbal fluency, and a worse free immediate recall of items from a word list. These findings open new avenues to the use of salivary cortisol levels as a possible biomarker for nonamnestic and multidomain mild cognitive impairment in elderly subjects.

Stress eliminates retrieval-induced forgetting—Does the oral application of cortisol?

It is well established that stress and glucocorticoids can affect memory. Psychosocial stress has been reported to eliminate retrieval-induced forgetting (RIF), the phenomenon that repeated retrieval of a subset of previously learned material impairs later recall of related, but non-retrieved information. The stress-related reduction of RIF has been found correlated with an increase in salivary cortisol levels. Based on these findings, the current placebo-controlled study examined the effect of an oral dose of 25mg hydrocortisone on the RIF effect in 37 healthy men. Even though participants in the hydrocortisone group showed a marked increase in salivary cortisol, retrieval-induced forgetting was not affected by the pharmacological treatment. Thus, cortisol administration alone in contrast to stress experience does not impair the RIF effect. However, participants with high state anxiety during retrieval practice did not show RIF, whereas participants with low state anxiety did. This finding suggests a role for state anxiety in stress-related elimination of retrieval-induced forgetting, perhaps indicative of a memory-modulating sympathetic nervous system effect.

Non-invasive measurement of adrenal response after standardized exercise tests in prepubertal children

To determine the feasibility of non-invasive evaluation of adrenal response in healthy prepubertal children by standardized exercise tests. On separate occasions, healthy prepubertal children performed a submaximal cycling test, a maximal cycling test, and a 20-m shuttle-run test. Salivary cortisol levels were determined before exercise, and 1 and 15 min after exercise. Immediately after cessation of the cycling and shuttle-run tests, salivary cortisol levels remained unchanged or decreased. Fifteen minutes after the shuttle-run test, salivary cortisol levels increased significantly. This increase in salivary cortisol levels was not observed 15 min after the cessation of the cycling tests. The results of this study demonstrate a different response in salivary cortisol levels after standardized cycling and running tests in prepubertal children. The increase in salivary cortisol levels found after a short standardized running test suggests that this may be a practical non-invasive method for evaluating adrenal response in healthy prepubertal children.

Estimation of Salivary Cortisol in Children with Rampant Caries

Dental profession is largely challenged with rampant caries and probable predisposing factors for the same have been evaluated for ages. There is considerable evidence that emotional disturbances may be a causative factor in some cases of rampant caries. Thus the objective of the present study was to estimate the levels of salivary cortisol in children with active rampant caries before and after caries control using electrochemiluminescence assay. A total of 60 children between the age group of 5 to 10 years of both sexes were selected for the study. A questionnaire was also included to evaluate predisposing factors for caries. The results showed that there was an increase in salivary cortisol levels in children with rampant caries, the level decreased gradually when observed for a period of three months following dental treatment which was statistically significant.

Feeding upon awakening in breastfeeding and bottlefeeding mothers does not affect the awakening cortisol response

An acute breastfeeding stimulus is generally followed by a transient decrease in cortisol levels in mothers. It is currently not clear whether breastfeeding upon waking up would affect the awakening cortisol response (ACR), a significant increase in salivary cortisol levels occurring within 30–45 min after awakening. In the present study, we measured the amplitude and stability of the ACR in response to infant feeding in women who were exclusively bottle-feeding (n = 16), or breastfeeding (n = 13) or feeding their child solid food (n = 12). The results show that the type of infant feeding did not affect the amplitude and stability of the ACR. Given that the ACR has been reported to reflect physical and psychological well-being, our finding that infant feeding upon waking up might not be a confounding factor in ACR studies on the postpartum population represents valuable methodological information.