Salivary alpha-amylase, secretory IgA and free cortisol as neurobiological components of the stress response in the acute phase of anorexia nervosa

Exploring the Relationship between Psychoneuroimmunology and Oral Diseases: A Comprehensive Review and Analysis

The relationship between psychoneuroimmunology (PNI) and oral health has recently garnered increasing attention due to the intricate interaction among psychological factors, the nervous system, immune responses, and oral diseases. This comprehensive review aims to elucidate the multifaceted connections between PNI and various oral conditions and conduct an in-depth analysis. Psychological factors, such as stress, anxiety, and depression, have been linked to oral microbiome alterations and immune function and the development and progression of oral diseases, such as periodontal disorders, oral ulcers, and temporomandibular disorders. Conversely, oral health conditions, particularly chronic periodontitis, have been associated with systemic inflammation, affecting mental health and overall well-being through neuroendocrine-immune pathways. Moreover, neural mechanisms, including the brain-gut axis and the autonomic nervous system, significantly influenced oral health through immune modulation and inflammatory responses. Understanding these complex interactions has implications for therapeutic interventions that target both psychological well-being and oral health outcomes. This review synthesizes current research findings from various disciplines, including immunology, neuroscience, dentistry, and psychology, to offer a comprehensive understanding of the bidirectional relationship between PNI and oral diseases. The implications of these interactions on treatment strategies, preventive measures, and interdisciplinary approaches underscore the need for integrated healthcare models that address psychological and oral health aspects to improve outcomes and quality of life in patients.

The role of short-chain fatty acids (SCFAs) in regulating stress responses, eating behavior, and nutritional state in anorexia nervosa: protocol for a randomized controlled trial

OBJECTIVE

This protocol proposes investigating the effects of short-chain fatty acids (SCFAs)-namely acetate, propionate, and butyrate-as mediators of microbiota-gut-brain interactions on the acute stress response, eating behavior, and nutritional state in malnourished patients with anorexia nervosa (AN). SCFAs are produced by bacterial fermentation of dietary fiber in the gut and have recently been proposed as crucial mediators of the gut microbiota's effects on the host. Emerging evidence suggests that SCFAs impact human psychobiology through endocrine, neural, and immune pathways and may regulate stress responses and eating behavior.

METHOD

We will conduct a randomized, triple-blind, placebo-controlled trial in 92 patients with AN. Patients will receive either a placebo or a mixture of SCFAs (acetate propionate, butyrate) using pH-dependent colon-delivery capsules for six weeks. This clinical trial is an add-on to the standard inpatient psychotherapeutic program focusing on nutritional rehabilitation.

HYPOTHESES

We hypothesize that colonic SCFAs delivery will modulate neuroendocrine, cardiovascular, and subjective responses to an acute laboratory psychosocial stress task. As secondary outcome measures, we will assess alterations in restrictive eating behavior and nutritional status, as reflected by changes in body mass index. Additionally, we will explore changes in microbiota composition, gastrointestinal symptoms, eating disorder psychopathology, and related comorbidities.

DISCUSSION

The findings of this study would enhance our understanding of how gut microbiota-affiliated metabolites, particularly SCFAs, impact the stress response and eating behavior of individuals with AN. It has the potential to provide essential insights into the complex interplay between the gut, stress system, and eating behavior and facilitate new therapeutic targets for stress-related psychiatric disorders. This protocol is prospectively registered with ClinicalTrials.gov, with trial registration number NCT06064201.

The Effect of Biological Treatment on Stress Parameters Determined in Saliva in Patients with Severe Psoriasis

Background and objectives: In psoriatic patients, stress is the most common aggravating factor. Despite the use of quality-of-life assessment questionnaires, diagnosing stress in psoriatic patients is not a flawless procedure. This study aimed to assess the usefulness of potential stress biomarkers in saliva for monitoring the treatment of psoriasis. Materials and methods: A total of 104 adult patients with severe psoriasis were included and randomly treated via biological treatment or symptomatic therapy: 84 received biological treatment, with 20 formed a control group receiving symptomatic therapy. The administered biological treatment was adalimumab, whilst in controls calcipotriol/betamethasone dipropionate topical gel and emollients were used. Patients were monitored monthly with a dermatological examination and the dispensing of a biological drug. During each of the four visits, the severity of the disease was assessed (PASI, BSA, and DLQI), and a sample of the patient’s saliva was taken. In all the participants, the saliva concentrations of immunoglobulin A (sIgA), α-amylase (sAA), and chromogranin A (CgA) were measured. Results: The majority of patients in both the study and control groups achieved clinical improvement, though favoring the group receiving biological treatment. The concentration of sIgA in the saliva was constantly increasing in the study group during subsequent visits (Fr = 27.26; p < 0.001). Meanwhile, there were no statistically significant changes in the control group during the same follow-up period (Fr = 6.66; p = 0.084). Levels of sAA underwent statistically significant changes in both groups (Fr = 58.02; p < 0.001—study group and Fr = 13.74; p = 0.003—control group). In the study group, a steady, statistically significant increase in sAA was observed from the first to the third visit. In the study group, a downward trend in CgA concentration was observed. In the control group, no significant differences in the level of CgA were obtained. Conclusions: sIgA, sAA, and CgA are potential markers of the severity of psoriasis and the associated stress reaction. Based on the presented observations, only sIgA and CgA seem to be valuable biomarkers for monitoring the effectiveness of the systemic treatment of psoriasis.

Hypothalamic-pituitary-adrenal axis activity and its relationship to the autonomic nervous system in patients with psychogenic erectile dysfunction

BACKGROUND

Psychological stress and its two stress response systems, the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), are closely related to psychogenic erectile dysfunction (pED). However, the analyses of perceived stress and stress systems in pED patients need to be more in-depth, especially the interactions between them.

METHODS

Our study included 75 patients with pEDs and 75 healthy men. The International Index of Erectile Function-5 (IIEF-5) and the 10-item Perceived Stress Scale (PSS-10) were used for assessing the severity of ED and perceived stress. All participants collected saliva samples on three consecutive days at eight specific times with strict reference to the time of morning awakening for measuring cortisol parameters and wore electrocardiography for 24 h to derive heart rate variability (HRV).

RESULTS

The PSS-10 scores of pED patients were significantly higher than the control group (p<0.001). Although PSS-10 and IIEF-5 scores were negatively correlated in pED patients, there was no statistical significance between them (r=-0.049, p=0.677). Compared with the control group, the HRV parameters of pED patients were significantly increased in LF/HF ratio (p=0.014) but significantly decreased in LF, HF, and pNN50 (p<0.001). However, the two groups had no statistically significant differences in cortisol variables (all p>0.05). The interaction between sympathovagal modulation (HF, rMSSD) and cortisol awakening response (CAR AUCi) explained significantly greater variance in perceived stress than either stress system alone. Higher parasympathetic activity combined with a higher cortisol awakening response was associated with greater perceived stress.

CONCLUSION

Our results suggested that the interrelation between ANS and HPA axis activity might enhance our comprehension of how stress affected the physical and mental health of pED patients.

Evaluation of psychological stress, cortisol awakening response, and heart rate variability in patients with chronic prostatitis/chronic pelvic pain syndrome complicated by lower urinary tract symptoms and erectile dysfunction

BACKGROUND

Mental stress and imbalance of its two neural stress systems, the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis, are associated with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and erectile dysfunction (ED). However, the comprehensive analyses of psychological stress and stress systems are under-investigated, particularly in CP/CPPS patients complicated by lower urinary tract symptoms (LUTS) and ED.

MATERIALS AND METHODS

Participants were 95 patients in CP/CPPS+ED group, 290 patients in CP/CPPS group, 124 patients in ED group and 52 healthy men in control group. The National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), the International Index of Erectile Function-5 (IIEF-5) and the International Prostate Symptom Score (IPSS) were used for assessing the disease severity of CP/CPPS, LUTS and ED. Psychometric self-report questionnaires including the Beck Anxiety Inventory (BAI), Perceived Stress Scale (PSS), Type A Personality Test (TAPT) and Symptom Checklist 90 (SCL-90) were completed for distress from physical symptoms. Twenty-five subjects per group were randomly selected for further investigating the changes of the HPA axis and ANS. Saliva samples were taken on 3 consecutive days at 8 specific times with strict reference to time of morning awakening for evaluation of free cortisol. Heart rate variability (HRV) as marker of the ANS was measured using 24 h electrocardiography, and time-and frequency-domain variables were analyzed.

RESULTS

The BAI and SCL-90 scores were significantly higher in the CP/CPPS+ED, CP/CPPS and ED groups compared with the control group (p < 0.01). The PSS scores of both groups with ED were significantly higher than the control group (p < 0.01). Compared with the CP/CPPS group, the differences of PSS, SCL-90 and TAPT scores were statistically significant in CP/CPPS+ED patients (p < 0.01). The IPSS scores were shown to have significantly positive correlations with BAI (r = 0.32, p < 0.0001), PSS (r = 0.18, p < 0.01) and SCL-90 (r = 0.19, p < 0.01) in the CP/CPPS patients. However, in all subjects, the IIEF-5 scores were shown to have significantly negative correlations with BAI (r = -0.17，p < 0.001), PSS (r = -0.25，p < 0.0001), SCL-90 (r = -0.20，p < 0.001) and quality of life score in NIH-CPSI (r = -0.14，p = 0.0075). Cortisol awakening response (CAR) parameters and diurnal cortisol levels did not significantly vary between the four groups. Time-dependent parameters of HRV also did not differ significantly across groups. In the frequency domain analysis, low frequency (LF) was significantly lower in ED patients when compared with CP/CPPS+ED patients (p = 0.044) and healthy controls (p = 0.005), high frequency (HF) power was significantly higher in healthy controls compared to patients with ED (p < 0.001), CP/CPPS (p < 0.001) and CP/CPPS+ED (p < 0.001), and the CP/CPPS+ED group had significantly higher LF/HF ratio than the control group (p = 0.001).

CONCLUSION

CP/CPPS and ED patients score exceedingly high on most psychosocial variables. The symptom scores of LUTS and ED positively correlate with the severity of psychological stress. Our findings also suggest that the ANS sympathovagal imbalance is associated with ED and LUTS in CP/CPPS, whereas HPA axis activity is not.

Expression of salivary immunoglobulins and their association with analgesic neuropeptide opiorphin in anorexia nervosa during adolescence

BACKGROUND

Patients who suffer from anorexia nervosa (AN) are characterized by exceedingly lower body weight, micro- and macro-nutrient deficiencies, and hyposalivation as compared to healthy subjects. In addition, AN may predispose to difficulties in oral health maintenance. However, little is known about the relationship between stress-dependent salivary neuro/immunopeptidergic biomarkers such as opiorphin and immunoglobulins (Ig) and AN.The aim of this case-control study was to evaluate salivary opiorphin and immunoglobulins in female children and adolescents diagnosed with AN compared to healthy controls.

METHODS

Adolescent patients with clinically-confirmed severe restrictive subtype AN (Body Mass Index BMI < 15 kg/m², mean age 15.0 ± 1.8, n = 83) were examined in the first week of hospital admission and compared to healthy matched controls (n = 79). Measurements of salivary opiorphin, IgA, IgG, IgM (ELISA technique), and oral hygiene levels (Plaque Control Record index-PCR) were performed.

RESULTS

In the AN group, a significantly higher concentration of opiorphin was evidenced (3.1 ± 4.1 ng/ml) compared to the control group (1.1 ± 1.2 ng/ml), (p < 0.001), contrary to IgM, which was significantly lower (311.0 ± 185.3 ng/ml) than in the control group (421.2 ± 168.1 ng/ml), (p < 0.001). There were no significant differences in the levels of IgA and IgG, despite a higher concentration of IgA in the AN group vs. controls (p = 0.14). Spearman analysis revealed a correlation between opiorphin and age (p < 0.05), but also with all immunoglobulins IgA, IgG, IgM (p = 0.006, p < 0.001, p < 0.001). Similarly a correlation was found between PCR index and immunoglobulins IgG, IgM (respectively p = 0.028, p < 0.001), and between body mass, BMI, IBW% and IgA, IgM (all p < 0.05).

CONCLUSIONS

In the acute phase of AN, salivary changes in opiorphin and immunoglobulins related to dental plaque suggest an essential role in oral health balance. Changes related to AN may affect the anti-inflammatory and analgesic components of saliva and suggest their use as neurobiological markers in severe malnutrition.

Dysfunction of Inflammatory Pathways and Their Relationship With Psychological Factors in Adult Female Patients With Eating Disorders

The attempts to clarify the origin of eating disorders (ED) have not been completely successful and their etiopathogenesis remains unknown. Current research shows an activation of the immune response in neuropsychiatric diseases, including ED. We aimed to investigate immune response parameters in patients with ED and to identify psychological factors influencing the inflammatory response. The relationship between inflammation markers and impulsivity and affective symptomatology was explored as well. Thirty-four adult female patients with current diagnosis of ED, none of them under psychopharmacological treatment (excluding benzodiazepines), were included in this study. Patients were compared with a healthy control group of fifteen adult females. The levels of inflammatory markers and indicators of oxidative/nitrosative stress were evaluated in plasma and/or in peripheral blood mononuclear cells (PBMCs). Subjects were assessed by means of different ED evaluation tools. Additionally, the Barratt Impulsiveness Scale, the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were also employed. Patients with ED shown increased plasma levels of the pro-inflammatory nuclear factor kappa B (NFκB) and the cytokine tumor necrosis factor-alpha (TNF-α), among other factors and an increment in the oxidative/nitrosative stress as well as increased glucocorticoid receptor (GR) expression levels in their PBMCs. Moreover, the inflammatory prostaglandin E₂ (PGE₂) correlated with impulsiveness and the anti-inflammatory prostaglandin J₂ (15d-PGJ₂) correlated with depressive symptomatology. Our results point towards a relationship between the immune response and impulsiveness and between the immune response and depressive symptomatology in female adult patients with ED.

Salivary Biomarkers (Opiorphin, Cortisol, Amylase, and IgA) Related to Age, Sex, and Stress Perception in a Prospective Cohort of Healthy Schoolchildren

Background

The use of easily accessible biomarkers for assessing young patients' health is weighty. This cohort study is aimed at measuring stress/immune biomarkers in the saliva of healthy school-age children and comparing subgroups according to age, sex, and stress perception. Material and Methods. 503 children under 12 years old (8.7 ± 1.3) were included with anthropometric evaluation (height, waist, hip circumference, body weight, and body mass index (BMI)). Levels of opiorphin (OPI), free cortisol, alpha-amylase (sAA), and secreted immunoglobulin (sIgA) were determined by quantitative assays (ELISA) in unstimulated saliva. Unpaired t-test, Welch test, and Mann-Whitney U test were applied for appropriate group comparisons, and the correlation between variables was analyzed with Spearman's rank coefficient. Results were considered significant at p < 0.05.

Results

sIgA and sAA exhibited significant differences depending on age and sex: IgA (ng/mL): 86 ± 68.6 vs. 104.9 ± 72.1 for (6-7 y.o.) and (8-11 y.o.), respectively, and 108.1 ± 80.1 vs. 94.6 ± 62.2 for male and females, respectively; sAA (U/mL): 78.9 ± 54.4 vs. 100.5 ± 81.2 for (6-7 y.o.) and (8-11 y.o.). No difference related to age or sex between groups was observed for cortisol and OPI. However, OPI levels were higher and correlated to prior stress exposure in children (0.31 ± 0.4 vs. 0.26 ± 0.5 ng/mL, p = 0.031). sAA was negatively correlated to low mood self-declaration in children in the last two weeks (r = -0.10, p = 0.045).

Conclusions

sIgA and sAA can be used as sex- and age-related biomarkers in children 6-12 y.o., which is not the case for free cortisol and opiorphin. However, OPI reflected previous exposure to stress, suggesting its use for evaluating stress-related changes in children.

Associations of Stress and Appetite Hormones with Binge Eating in Females with Anorexia Nervosa after Weight Restoration: A Longitudinal Study

Binge eating is a transdiagnostic eating disorder symptom that can occur in patients with anorexia nervosa (AN), persisting after weight restoration, and impeding their recovery. However, little is known about the biological predictors of binge eating after AN weight restoration. The goals of this exploratory study of 73 females with AN were: (1) to examine changes in cortisol, the adrenocorticotropic hormone, norepinephrine, ghrelin (total and active), and leptin levels across the admission, discharge, and 3 months post-discharge from the inpatient AN weight restoration; and (2) to determine whether the target hormones were associated with objective or subjective binge eating (OBE or SBE). The participants completed the self-reported Eating Disorder Examination Questionnaire, Beck Anxiety Inventory, and Beck Depression Inventory-II, and provided fasting whole blood samples for hormone assays. The results showed significant changes in body mass index (BMI), cortisol, total ghrelin, and leptin levels over the three time points. The cortisol levels at admission and discharge were significantly associated with the number of SBE episodes at 3 months post-discharge. Findings suggest the need to replicate and confirm the role of cortisol in predicting the emergence of SBE and uncover the mechanisms underlying SBE and cortisol to prevent SBE and its negative consequences.

Role of the Novel Peptide Phoenixin in Stress Response and Possible Interactions with Nesfatin-1

The novel peptide phoenixin was shown to be involved in several physiological processes ranging from reproduction to food intake. Interest in this protein has steadily increased over the last few years and its known implications have become much broader, playing a role in glucose homeostasis, anxiety, nociception, and pruritus. Phoenixin is expressed in a multitude of organs such as the small intestine, pancreas, and in the hypothalamus, as well as several other brain nuclei influencing numerous physiological functions. Its highly conserved amino-acid sequence amongst species leads to the assumption, that phoenixin might be involved in essential physiological functions. Its co-expression and opposing functionality to the extensively studied peptide nesfatin-1 has given rise to the idea of a possible counterbalancing role. Several recent publications focused on phoenixin’s role in stress reactions, namely restraint stress and lipopolysaccharide-induced inflammation response, in which also nesfatin-1 is known to be altered. This review provides an overview on the phoenixins and nesfatin-1 properties and putative effects, and especially highlights the recent developments on their role and interaction in the response to response.

Effects of stress on chewing and food intake in patients with anorexia nervosa

OBJECTIVE

The present study investigates the impact of psychosocial stress on chewing and eating behavior in patients with anorexia nervosa (P_AN ).

METHOD

The eating and chewing behavior of P_AN were examined in a standardized setting by means of a chewing sensor. These procedures encompassed n = 19 P_AN , age, and gender matched to n = 19 healthy controls (HC). Food intake and chewing frequency were assessed in two experimental conditions: rest versus stress (via Trier Social Stress Test). To verify stress induction, two appraisal scales were employed. In addition, chronic stress, psychological distress and eating disorder symptoms were assessed.

RESULTS

In terms of food intake and chewing frequency, the results of the 2x2 ANOVA demonstrated a significant effect of condition and group. During stress, all participants demonstrated a higher chewing frequency and a decreased ingestion. In general, patients ate less at a lower chewing frequency (vs. HC). However, sample specific analyses demonstrated that the eating and chewing behavior of P_AN remained unchanged regardless of the condition, except for their drinking. Food choices were comparable between the groups, but appetite values significantly differed.

DISCUSSION

The increase in chewing frequency in all participants during stress suggests that chewing might impact affect regulation, however, not specifically in P_AN . Future research should clarify to what extent the normalization of chewing behavior could ameliorate ED-symptoms (incl. food intake) in P_AN . The application of a chewing sensor could support this aim and future interventions.

Stress/Immune Biomarkers in Saliva among Children with ADHD Status

Background. This cross-sectional study aimed to evaluate stress and immune biomarkers in saliva samples of attention-deficit/hyperactivity disorder ADHD compared to healthy non-ADHD children. Material and methods. A total of 132 children under 11 years old (8.5 ± 1.1) enrolled in a cross-sectional study: with confirmed ADHD (n = 60) and healthy controls (n = 72). The clinical evaluation included physical measurements (height, waist, hip circumference, body weight, body mass index BMI, BMI z-score) and unstimulated saliva collection and measurements of free cortisol, salivary alpha-amylase (sAA), and secreted immunoglobulins (sIgA, IgG, and IgM) with quantitative assay (ELISA) analysis. Unpaired t-test, Welch test, or Mann-Whitney U test were applied for group comparisons when appropriate, and the correlation between variables was analyzed with Spearman's rank coefficient. Results were considered significant at p < 0.05. Results. In the ADHD group, body weight (p ≤ 0.01), BMI (p ≤ 0.009), and hip circumference (p ≤ 0.001) significantly differed, while waist size and BMI z-score did not (p > 0.05). Significant elevation of the salivary sAA (p = 0.03), sIgA (p = 0.02), and IgM (p ≤ 0.001) biomarkers were detected, without differences in the morning cortisol (p > 0.05). Significant correlations between cortisol and BMI, hip size, and IgA, as well as between IgG and sAA and IgA were obtained. Conclusions. Saliva can be used to monitor ADHD status with regard to biomarkers indicating the hypothalamus-pituitary-adrenal axis, as HPA axis, and sympathetic activity. The results indicate that morning collection of saliva in contrast to unchanged salivary cortisol, may evaluate mentioned above system dysregulations by measurements of sAA and immunoglobulins among ADHD children.

Cortisol reactivity in patients with anorexia nervosa after stress induction

There is a need of experimental studies on biomarkers in patients with anorexia nervosa (P_AN), especially in the context of stress, in order to foster understanding in illness maintenance. To this end, the cortisol response to an acute stressor was investigated in n = 26 P_AN (BMI: 19.3 ± 3.4 kg/m²), age, and gender matched to n = 26 healthy controls (HC; BMI: 23.08 ± 3.3 kg/m²). For this purpose, salivary cortisol parameters were assessed in two experimental conditions: (1) rest/no intervention and (2) stress intervention (TSST; Trier Social Stress Test). In addition, psychological indicators of stress were assessed (Primary Appraisal Secondary Appraisal, Visual Analogue Scale, and Trier Inventory for the assessment of Chronic Stress), as well as psychological distress, depression, and eating disorder (ED) symptoms. A 2 × 2 × 8 ANOVA demonstrated elevated cortisol levels in P_AN in the resting condition. In the stress intervention no significant group effect in terms of cortisol (F (1, 50) = 0.69; p = 0.410; [Formula: see text]). A significant condition (F (1, 50) = 20.50; p = 0.000; [Formula: see text]) and time effect (F(2.71, 135.44) = 11.27; p = 0.000; [Formula: see text]) were revealed, as well as two significant interaction effects. First: Condition × group (F (1, 50) = 4.17, p = 0.046; [Formula: see text]) and second: Condition × time (F (2.71, 135.44) = 16.07, p = 0.000, [Formula: see text]). In terms of AUC_G, no significant differences between both groups were exhibited. Regardless, significant results were evinced in terms of an increase (AUC_i: F(1, 50) = 20.66, p = 0.015, [Formula: see text]), baseline to peak (+20 min post-TSST: t₅ = 16.51 (9.02), p = 0.029) and reactivity (M_PAN = 0.73 vs. M_HC = 4.25, p = 0.036). In addition, a significant correlation between AUC_G and BMI: r (24) = -0.42, p = 0.027 was demonstrated, but not between AUC_i and BMI (r (24) = -0.26, p = 0.20). Psychological indices suggested higher levels of chronic and perceived stress in P_AN relative to HC. However, stress perception in the stress condition (VAS) was comparable. Additional analyses demonstrated that ED-symptoms are highly correlated with psychological distress and depression, but not with BMI. In addition, it could be demonstrated that reactivity is rather related to ED-symptoms and psychological burden than to BMI. In conclusion, P_AN showed elevated basal cortisol levels at rest and exhibited a blunted cortisol reactivity to the TSST as evinced by salivary cortisol parameters. Further, it was shown that weight recovery influences reversibility of hypercortisolemia, i.e., cortisol levels normalize with weight gain. However, HPAA (hypothalamus-pituitary-adrenal axis) irregularities in terms of reactivity persist even at a BMI ≤ 19.3 (±3.4). Our data suggest that pronounced psychological burden in P_AN, have a greater impact on the HPAA functionality (secondary to the ED) than BMI itself.

The diagnosis of eating disorders through mid-infrared spectroscopy of the gingival crevicular fluid: a pilot trial

PURPOSE

Eating disorders (EDs) are characterized by a persistent disturbance of eating patterns, leading to poor psychological and physical health. EDs' symptoms are diverse, but their biochemical manifestations can be identified in biofluids, as the gingival crevicular fluid (GCF). The development of a rapid and accurate analytical diagnostic technique, able to provide a wider comprehension of established biochemical abnormalities, would greatly assist EDs' management. Mid-infrared (MIR) spectroscopy gathers all the referred features, and is considered a fingerprint technique. In this pilot trial, the GCF discrimination of patients with EDs and controls was accessed through MIR spectroscopy, further elucidating the relevant spectral differences between both groups.

METHODS

GCF was collected from 20 women with ED diagnosis and from age-matched controls. Principal component analysis and partial least squares discriminant analysis (PLSDA) were conducted on GCF MIR spectra. Different PLSDA models were considered to address the predictive capability regarding patient identification, sampling site, and presence of EDs.

RESULTS

MIR spectroscopy was capable to discriminate GCF samples, between EDs and controls, with 84.1% of correct predictions. Regression coefficient vectors' analyses revealed that major differences were related to higher protein content in EDs.

CONCLUSIONS

Whether further studies are needed to validate the attained data, GCF MIR analysis may be regarded as an innovative, fast, and low-cost technique to assist on early diagnosis and clinical follow-up of EDs' patients.

LEVEL OF EVIDENCE

Level IV, case-control trial.

Coping strategies and stress-induced natural killer cell redistribution in women with eating disorders

BACKGROUND

Patients with eating disorders (ED) are very sensitive and responsive to psychosocial stress. Stress response includes changes in immune cell distribution and may be modulated by the capability to cope with stressors. Thus, the present study sought to analyze the association between coping strategies and immune response (natural killer [NK] cell redistribution following psychosocial stress) in patients with anorexia nervosa (AN) and bulimia nervosa (BN) and healthy controls (HC).

METHOD

Twenty-four AN patients, 29 BN patients, and 58 HC were studied. A multidimensional assessment tool, the COPE Inventory, was used to assess coping strategies. The number of NK cells was quantified in peripheral blood before and after the application of the Trier Social Stress Test (TSST). Potentially mediating variables, such as weight status, severity of eating pathology, depression, anxiety, and impulsivity were controlled.

RESULTS

The three groups differed in intensity and direction of cell redistribution: The TSST was followed in BN patients by a significant decrease in the number of NK cells, whereas HC displayed a moderate decrease and AN a clear increase. Specific correlations between coping strategies and NK cell mobilization were found, especially in BN patients (positive for "planning" and negative for "substance abuse").

CONCLUSION

Recognition and subsequent modification of the dysfunctional coping strategies used by patients with ED could contribute to improving their immune status, strengthening their resilience and increasing their ability to overcome the disease.

Restraint stress increases the expression of phoenixin immunoreactivity in rat brain nuclei

Phoenixin is a recently discovered peptide, which has been associated with reproduction, anxiety and food intake. Based on a considerable co-localization it has been linked to nesfatin-1, with a possible antagonistic mode of action. Since nesfatin-1 is known to play a role in anxiety and the response to stress, this study aims to investigate the effects of a well-established psychological stress model, restraint stress, on phoenixin-expressing brain nuclei and phoenixin expression in rats. Male Sprague-Dawley rats were subjected to restraint stress (n = 8) or left undisturbed (control, n = 6) and the brains processed for c-Fos- and phoenixin immunohistochemistry. The number of c-Fos expressing cells was counted and phoenixin expression assessed semiquantitatively. Restraint stress significantly increased c-Fos expression in the dorsal motor nucleus of vagus nerve (DMN, 52-fold, p < 0.001), raphe pallidus (RPa, 15-fold, p < 0.001), medial part of the nucleus of the solitary tract (mNTS, 16-fold, p < 0.001), central amygdaloid nucleus, medial division (CeM, 9-fold, p = 0.01), supraoptic nucleus (SON, 9-fold, p < 0.001) and the arcuate nucleus (Arc, 2.5-fold, p < 0.03) compared to control animals. Also phoenixin expression significantly increased in the DMN (17-fold, p < 0.001), RPa (2-fold, p < 0.001) and mNTS (1.6-fold, p < 0.001) with positive correlations between c-Fos and phoenixin (r = 0.74-0.85; p < 0.01) in these nuclei. This pattern of activation suggests an involvement of phoenixin in response to restraint stress. Whether phoenixin mediates stress effects or is activated in a counterbalancing fashion will have to be further investigated.

Mindfulness versus Physical Exercise: Effects of Two Recovery Strategies on Mental Health, Stress and Immunoglobulin A during Lunch Breaks. A Randomized Controlled Trial

This research analyses the effects of mindfulness meditation (MM) and physical exercise (PE), practised as daily recovery activities during lunch breaks, on perceived stress, general mental health, and immunoglobin A (IgA). A three-armed randomized controlled trial with 94 employees was conducted for five weeks including two follow-up sessions after one and six months. Daily practice lasted 30 min maximum. Perceived stress and general mental health questionnaires and saliva samples were used. There were significant differences in time factor comparing pre- and post-test of Perceived Stress Questionnaire (PSQ) both for PE [Mdiff = 0.10, SE = 0.03, p = 0.03], and for MM [Mdiff = 0.09, SE = 0.03, p = 0.03]. Moreover, there were significant differences of interaction factor when comparing MM vs. PE in total score at pre-post [F = −2.62 (6, 168.84), p = 0.02, ω² = 0.09], favoring PE with medium and high effect sizes. Regarding General Health Questionnaire (GHQ) variable, practicing MM showed significant effects in time factor compared to pre-Fup2. No significant differences were found for IgA. Thus, practicing both MM and PE as recovery strategies during lunch breaks could reduce perceived stress after five weeks of practice, with better results for PE. Moreover, practicing MM could improve mental health with effects for 6 months.

Is there a link between stress and immune biomarkers and salivary opiorphin in patients with a restrictive-type of anorexia nervosa?

Objectives: Opiorphin is a salivary peptide with analgesic and antidepressant properties. Its relationship with the hypothalamic-pituitary-adrenal, autonomic nervous and immune systems may provide understanding of chronic stress, especially in anorexia nervosa (AN). This study investigated a possible correlation between opiorphin and stress/immune biomarkers, cortisol, salivary alpha-amylase (sAA) and secretory immunoglobulin A (sIgA), in saliva of patients with restrictive-type AN.Methods: A case-control clinical trial was conducted in 92 AN patients (+75 healthy controls). Unstimulated salivary samples were taken during the acute stage of AN, measurements of cortisol, sAA, sIgA and opiorphin were performed with a quantitative assay (enzyme-linked immunosorbent assay, P < 0.05).Results: AN patients displayed an increase in cortisol (P < 0.001) and sIgA (P < 0.001) but not in sAA (P = 0.279) levels. Distinct correlation between these two parameters and body-weight indexes were observed. Opiorphin levels were neither correlated to stress and immune biomarkers, nor to salivary flow rate.Conclusions: The effect of stress responses can be reliably assessed in saliva in AN patients. The difference between sIgA and cortisol indicate that they can both be used for mental stress assessment in saliva. Modulation of opiorphin by chronic stress was not confirmed. Unchanged sAA indicates a partial adaptation of human organism to severe condition during malnutrition.

Dysfunction of inflammatory pathways in adolescent female patients with anorexia nervosa

BACKGROUND

The pathogenesis of Eating Disorders is still unknown. However, a growing body of evidence shows that there are changes in cytokine levels and an alteration in the stress response in patients with anorexia nervosa (AN). For this reason, we decided to test whether there are differences in immune parameters involved in the regulation of the inflammatory response between female adolescents with AN and healthy adolescents.

METHODS

The sample 27 drug-naïve AN patients the study sample included 27 AN patients at a very early stage of the disease and 23 healthy controls. Plasma and peripheral blood mononuclear cells (PBMCs) were obtained for biochemical study.

RESULTS

Plasma levels of the pro-inflammatory cytokines TNF-α and IL-1β were significantly increased in patients with AN, while the levels of prostaglandins PGE₂ (proinflammatory) and 15d-PGJ₂, (anti-inflammatory) were lower compared with controls. Protein expression in PBMCs of cyclooxygenase-2 (COX-2) and the activated forms of the mitogen-activated protein kinases p38 and ERK were also increased in the AN group. Expression levels of the anti-inflammatory factor peroxisome proliferator-activated receptor gamma (PPARγ) were significantly decreased in patients. Plasma levels of lipid peroxidation markers -TBARS- were not increased in patients with AN. Components of the biochemical inflammatory response (COX-2, PGE₂, TBARS, 15d-PGJ₂, ERK, p65 NFκB) and glucocorticoid receptor -GR- expression and the scores on the impulsivity measures in the BARRATT, EDI and BITE questionnaires showed a significant correlation within the AN patients group.

CONCLUSIONS

The results for female adolescent patients with AN indicate that there is a dysfunction of intra- and intercellular inflammatory pathways characterized by higher levels of pro-inflammatory parameters in plasma and a decrease in one of the controlling cytoplasmic-nuclear pathways implicated in their modulation (i.e. PPARγ) with, at this very early stage of the disease, no effect on oxidative stress markers plasma levels. Most notably, higher severity of illness (restrictive and purging behaviour) correlated with higher levels of inflammatory markers.

Activity Based Anorexia as an Animal Model for Anorexia Nervosa-A Systematic Review

Anorexia nervosa (AN) is a severe eating disorder affecting around 1 per 100 persons. However, the knowledge about its underlying pathophysiology is limited. To address the need for a better understanding of AN, an animal model was established early on in the late 1960's: the activity-based anorexia (ABA) model in which rats have access to a running wheel combined with restricted food access leading to self-starving/body weight loss and hyperactivity. Both symptoms, separately or combined, can also be found in patients with AN. The aim of this systematic review was to compile the current knowledge about this animal model as well as to address gaps in knowledge. Using the data bases of PubMed, Embase and Web of science 102 publications were identified meeting the search criteria. Here, we show that the ABA model mimics core features of human AN and has been characterized with regards to brain alterations, hormonal changes as well as adaptations of the immune system. Moreover, pharmacological interventions in ABA animals and new developments, such as a chronic adaptation of the ABA model, will be highlighted. The chronic model might be well suited to display AN characteristics but should be further characterized. Lastly, limitations of the model will be discussed.

Differences in cortisol concentrations in adolescents with eating disorders: a systematic review

OBJECTIVE

To perform a systematic review of the literature for scientific evidence of possible differences in cortisol concentrations in adolescents with eating disorders.

SOURCE OF DATA

Electronic searches were conducting in the PubMed, Scientific Electronic Library Online, Virtual Health Library, and Science Direct databases for articles published between 2007 and 2017 using the keywords, cortisol, hydrocortisone; eating disorders, bulimia, bulimia nervosa, anorexia, anorexia nervosa; adolescence, adolescent, adolescents.

SYNTHESIS OF DATA

A total of 192 articles were found. After the analysis of the eligibility criteria using the PRISMA method, 19 articles were selected for the present review. Most studies were conducted in Europe. Adolescents diagnosed with anorexia nervosa were evaluated in all studies, except one, when other eating disorders were investigated. Blood was the means used for the determination of cortisol. In ten studies, cortisol levels were higher in the group with anorexia than the control group and a reduction in cortisol levels occurred in the adolescents after being submitted to nutritional recovery.

CONCLUSIONS

Patients with eating disorders may have several clinical consequences, such as changes in body fat distribution, changes in bone mineral density, worsening of neurocognitive ability, and endocrine changes (e.g., hypercortisolemia), which in turn can lead to hyperglycemia, insulin resistance, hypertension, and increased risk of infections. The findings demonstrate that adolescents with eating disorders, especially anorexia nervosa, have increased cortisol levels, which are reduced after the treatment period. Further studies on differences in cortisol concentrations in adolescents with other eating disorders are needed, using different methods.

Anorexia Nervosa and Autism Spectrum Disorders: Future Hopes Linked to Mucosal Immunity

Mental health is becoming a public health priority worldwide. Anorexia nervosa and autism spectrum disorders are 2 important types of childhood disorders with a bad prognosis. They share cognitive impairments and, in both cases, the microbiota appears to be a crucial factor. Alteration of the microbiota-gut-brain axis is an appealing hypothesis to define new pathophysiological mechanisms. Mucosal immunity plays a key role between the microbiota and the brain. The mucosal immune system receives and integrates messages from the intestinal microenvironment and the microbiota and then transmits the information to the nervous system. Abnormalities in this sensorial system may be involved in the natural history of mental diseases and might play a role in their maintenance. This review aims to highlight data about the relationship between intestinal mucosal immunity and these disorders. We show that shared cognitive impairments could be found in these 2 disorders, which both present dysbiosis. This literature review provides details on the immune status of anorexic and autistic patients, with a focus on intestinal mucosal factors. Finally, we suggest future research hypotheses that seem important for understanding the implication of the gut-brain-axis in psychiatric diseases.

Association of Brain Reward Learning Response With Harm Avoidance, Weight Gain, and Hypothalamic Effective Connectivity in Adolescent Anorexia Nervosa

IMPORTANCE

Anorexia nervosa (AN) is associated with adolescent onset, severe low body weight, and high mortality as well as high harm avoidance. The brain reward system could have an important role in the perplexing drive for thinness and food avoidance in AN.

OBJECTIVE

To test whether brain reward learning response to taste in adolescent AN is altered and associated with treatment response, striatal-hypothalamic connectivity, and elevated harm avoidance.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional multimodal brain imaging study, adolescents and young adults with AN were matched with healthy controls at a university brain imaging facility and eating disorder treatment program. During a sucrose taste classical conditioning paradigm, violations of learned associations between conditioned visual and unconditioned taste stimuli evoked the dopamine-related prediction error (PE). Dynamic effective connectivity during sweet taste receipt was studied to investigate hierarchical brain activation across the brain network that regulates eating. The study was conducted from July 2012 to May 2017, and data were analyzed from June 2017 to December 2017.

MAIN OUTCOMES AND MEASURES

Prediction error brain reward response across the insula, caudate, and orbitofrontal cortex; dynamic effective connectivity between hypothalamus and ventral striatum; and treatment weight gain, harm avoidance scores, and salivary cortisol levels and their correlations with PE brain response.

RESULTS

Of 56 female participants with AN included in the study, the mean (SD) age was 16.6 (2.5) years, and the mean (SD) body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was 15.9 (0.9); of 52 matched female controls, the mean (SD) age was 16.0 (2.8) years, and the mean (SD) BMI was 20.9 (2.1). Prediction error response was elevated in participants with AN in the caudate head, nucleus accumbens, and insula (multivariate analysis of covariance: Wilks λ, 0.707; P = .02; partial η2 = 0.296), which correlated negatively with sucrose taste pleasantness. Bilateral AN orbitofrontal gyrus rectus PE response was positively correlated with harm avoidance (right ρ, 0.317; 95% CI, 0.091 to 0.539; P < .02; left ρ, 0.336; 95% CI, 0.112 to 0.550; P < .01) but negatively correlated with treatment BMI change (right ρ, -0.282; 95% CI, -0.534 to -0.014; P < .04; left ρ, -0.268; 95% CI, -0.509 to -0.018; P < .045). Participants with AN showed effective connectivity from ventral striatum to hypothalamus, and connectivity strength was positively correlated with insula and orbitofrontal PE response. Right frontal cortex PE response was associated with cortisol, which correlated with body dissatisfaction.

CONCLUSIONS AND RELEVANCE

These results further support elevated PE signal in AN and suggest a link between PE and elevated harm avoidance, brain connectivity, and weight gain in AN. Prediction error may have a central role in adolescent AN in driving anxiety and ventral striatal-hypothalamus circuit-controlled food avoidance.

Study of salivary and serum vaspin and total antioxidants in anorexia nervosa

OBJECTIVES

Patients with anorexia nervosa (AN) are primarily at high risk of multiple somatic complications, including oral diseases. In recent years, a number of new molecules that may play a potentially important role in AN progress and prognosis have been identified in saliva, but their exact roles are still poorly understood. Two such group of substances are antioxidants and vaspin. The purpose of this observational, cross-sectional study was to measure both the salivary and serum total antioxidant status (TAS), and vaspin (VASP) concentrations of patients with AN in comparison to an average population.

MATERIAL AND METHODS

Ninety subjects participated (30 patients with AN, 60 matched healthy control subjects). A clinical examination was made, and blood and salivary samples were taken during the acute stage of AN (BMI < 15 kg/m²) in the first week of hospitalization. Enzyme immunoassay (ELISA) suitable for measuring VASP and colorimetric assay for TAS were used.

RESULTS

Anorexic patients had significant reductions in salivary flow, TAS, and an elevation in VASP levels in their saliva and serum. Significant correlations between TAS, VASP, salivary flow, and nutritional status were detected.

CONCLUSION

Determination of TAS and VASP in combined biological material confirmed that saliva might be a reliable non-invasive source of information for potent nutritional biomarkers.

CLINICAL RELEVANCE

Our findings suggest that VASP cannot be excluded, as its increased concentration in saliva is an adaptive mechanism in reduced TAS, one resulting from diminished salivary secretion. It is therefore worth conducting further research aimed at recognizing the role of TAS and VASP in the saliva of underweight patients.

Influence of the way of reporting alpha-Amylase values in saliva in different naturalistic situations: A pilot study

The objective of this pilot study was to compare the different ways of measuring salivary alpha-amylase (sAA, enzymatic vs. concentration) and to evaluate the influence that the different ways of reporting the results can have in sAA interpretation. For this purpose, sAA was measured by direct quantification and also by an enzymatic assay in three different naturalistic situations, a physical stressor (situation 1) and two mental stressors of different intensity (situations 2 and 3). The results were expressed in three different ways (without correction, multiplied by flow rate and divided by protein concentration). sAA concentration and activity increased just after situations 1 and 3. When values were multiplied by the flow rate, significant changes after situation 1 were detected only for sAA activity but not for sAA concentration, being these changes of lower significance and magnitude that those observed for sAA activity without any correction. In addition, a significant increase in sAA activity was found at T+15 in situation 2. In situation 3 the significant decrease in sAA at T+15 disappeared. When values were divided by protein concentration, there were no significant changes in situations 1 or 3, but a decrease in situation 2 at T+0 and an increase at T+15. sAA activity and concentration showed a significant correlation in all situations. This pilot study points out that the way of expressing sAA can influence the results obtained in different stress models and also their interpretation. Therefore, how sAA is reported and the factors involved in the different ways of expressing sAA, should be taken into consideration for an objective interpretation of sAA values.