Salivary Alpha-amylase Levels Research Articles

PSYCHOLOGICAL FACTORS, LEVELS OF ALPHA-AMYLASE, AND ORAL LICHEN PLANUS: A CASE-CONTROL STUDY

Objective To evaluate psychological factors (anxiety, depression, and stress) and levels of salivary alpha-amylase in individuals with oral lichen planus. Study Design A case-control study was conducted, with the case group (n = 23) composed of individuals with clinical and histopathologic diagnosis of oral lichen planus, and the control group (n = 23) composed of individuals without the disease, matched by sex and age. Beck Anxiety and Depression Inventories and Perceived Stress Scale were used, and levels of alpha-amylase at 3 time points throughout the day (upon waking, 30 minutes after waking up, and before going to sleep) were determined. Data were statistically analyzed using the Mann-Whitney and Student t test and the Spearman correlation coefficient. The adopted significance level was 5%. Results Individuals with oral lichen planus had higher anxiety (P = .000), depression (P = .001) and perceived stress (P = .001) scores, as well as higher secretory pattern of salivary alpha-amylase 30 minutes after waking (P = .04). Conclusions It was observed an association between oral lichen planus and anxiety, depression and stress scores, and levels of alpha-amylase.

Effect of Brief Biofeedback via a Smartphone App on Stress Recovery: Randomized Experimental Study.

BackgroundSmartphones are often vilified for negatively influencing well-being and contributing to stress. However, these devices may, in fact, be useful in times of stress and, in particular, aid in stress recovery. Mobile apps that deliver evidence-based techniques for stress reduction, such as heart rate variability biofeedback (HRVB) training, hold promise as convenient, accessible, and effective stress-reducing tools. Numerous mobile health apps that may potentially aid in stress recovery are available, but very few have demonstrated that they can influence health-related physiological stress parameters (eg, salivary biomarkers of stress). The ability to recover swiftly from stress and reduce physiological arousal is particularly important for long-term health, and thus, it is imperative that evidence is provided to demonstrate the effectiveness of stress-reducing mobile health apps in this context.ObjectiveThe purpose of this research was to investigate the physiological and psychological effects of using a smartphone app for HRVB training following a stressful experience. The efficacy of the gamified Breather component of the Happify mobile health app was examined in an experimental setting.MethodsIn this study, participants (N=140) underwent a laboratory stressor and were randomly assigned to recover in one of three ways: with no phone present, with a phone present, with the HRBV game. Those in the no phone condition had no access to their phone. Those in the phone present condition had their phone but did not use it. Those in the HRVB game condition used the serious game Breather on the Happify app. Stress recovery was assessed via repeated measures of salivary alpha amylase, cortisol, and self-reported acute stress (on a 1-100 scale).ResultsParticipants in the HRVB game condition had significantly lower levels of salivary alpha amylase during recovery than participants in the other conditions (F2,133=3.78, P=.03). There were no significant differences among the conditions during recovery for salivary cortisol levels or self-reported stress.ConclusionsThese results show that engaging in a brief HRVB training session on a smartphone reduces levels of salivary alpha amylase following a stressful experience, providing preliminary evidence for the effectiveness of Breather in improving physiological stress recovery. Given the known ties between stress recovery and future well-being, this study provides a possible mechanism by which gamified biofeedback apps may lead to better health.

The impact of dental treatment and age on salivary cortisol and alpha-amylase levels of patients with varying degrees of dental anxiety

BackgroundThe purpose of this study was to assess the salivary cortisol and salivary alpha-amylase levels in children aged between 6 and 9 years, 3 months and 1 year after the successful completion of dental treatment through either pharmacological or non-pharmacological behavior management techniques.MethodsA total of 1567 patients aged between 6 and 9 years who had completed dental treatment were screened. A total of 703 patients who were caries free at the end of 3 months were classified based on Frankl behavior score and administered the Arabic version of the Children’s Fear Survey Schedule- Dental Subscale (CFSS-DS) and accordingly allocated to one of three groups; (Phobic Patients, Anxious Patients, Control Group). A total of 183 patients met the inclusion criteria and were followed up for 1 year. A total of 151 patients completed the study. Patients’ heart rate on recall, salivary cortisol and salivary amylase were compared between the groups.ResultsThe results of the study showed that amylase and cortisol levels had a significant association with the level of dental fear. The phobic patients had the highest levels of salivary amylase and salivary cortisol levels with no significant associations observed with either heart rate or extent of dental treatment. Control and anxious patients had significantly lower amylase levels when compared to phobic patients. There was no significant difference between the salivary cortisol levels of anxious and phobic patients. These findings were replicated on 1-year recall.ConclusionsWithin the limitations of this study we can conclude that salivary amylase is an indicator of of acute stress that can differentiate between anxiety and dental fear; while salivary cortisol appears to be a marker of long-term stress that lacks the sensitivity to differentiate between the two.

Effects of glucocorticoid and noradrenergic activity on spatial learning and spatial memory in healthy young adults

BackgroundAcute stress leads to a rapid release of noradrenaline and glucocorticoids, which in turn influence cognitive functions such as spatial learning and memory. However, few studies have investigated noradrenergic and glucocorticoid effects on spatial learning and memory in humans. Therefore, we examined the separate and combined effects of noradrenergic and glucocorticoid stimulation on spatial learning and memory. MethodsOne hundred and four healthy men (mean age = 24.1 years ±SD 3.5) underwent the virtual Morris Water Maze (vMWM) task to test spatial learning and spatial memory retrieval after receiving either 10 mg hydrocortisone or 10 mg yohimbine (an alpha 2-adrenergic receptor antagonist that increases noradrenergic activity), 10 mg hydrocortisone and 10 mg yohimbine combined, or placebo. The vMWM task took place 90 min after yohimbine was administered and 75 min after hydrocortisone was administered. Placebo was given at the same times. Salivary cortisol and alpha amylase levels were measured to check pharmacological stimulation. ResultsHydrocortisone and yohimbine increased salivary cortisol and alpha amylase levels. Participants’ task performance improved over time, suggesting successful spatial learning. However, separate and combined noradrenergic and glucocorticoid stimulation had no effect on spatial learning and spatial memory retrieval compared with placebo. ConclusionsIn healthy young men, hydrocortisone and/or yohimbine did not alter spatial learning or spatial memory retrieval. Importantly, pharmacological stimulation took place prior to learning. Further studies should examine the effects of glucocorticoid and noradrenergic stimulation during encoding, consolidation, and retrieval.

A single bout of hard RPE-based cycling exercise increases salivary alpha-amylase

Exercise exerts beneficial effects on cognition, in part by stimulating an arousal response that includes the release of catecholamines. Sympathetic nervous system arousal and activation of the noradrenergic system in particular may enhance cognitive performance. Measurement of salivary alpha-amylase, a non-invasive biomarker of central noradrenergic activity, is a promising avenue for characterizing the arousal-mediated effects of exercise on cognition. However, the effectiveness of high-intensity acute exercise, and the time course of sAA concentrations following exercise, has not been clearly described. The purpose of this study was to determine the effects of 20 min of perceived exertion-based high-intensity cycling exercise on salivary alpha-amylase levels in healthy young adults. We utilized a repeated-measures design to examine the sAA response to cycling exercise, rest, and an emotional picture viewing task. Thirty-two participants between the ages of 18–30 viewed pleasant, neutral, and unpleasant pictures from the International Affective Picture System. Before and after the task, participants completed either 20 min of seated rest or cycling exercise at an intensity corresponding to 15 (“hard”) on Borg's Ratings of Perceived Exertion scale. Salivary alpha-amylase was assessed at time points immediately before and after rest, exercise, and the picture viewing task. Exercise elicited a robust increase in salivary alpha-amylase approximately six times higher than that induced by emotional picture viewing. Importantly, the observed exercise-induced increase in salivary alpha-amylase returned to a level comparable to baseline after ten minutes. These findings have meaningful implications for future work characterizing the relationship between exercise and arousal-mediated effects on cognitive performance.

The Association of Salivary Biomarkers With the Severity of Obstructive Sleep Apnea and Concomitant Hypertension

BackgroundWe aimed to assess the association between salivary alpha-amylase and salivary cortisol, and obstructive sleep apnea (OSA) severity. MethodsFifty-eight adults with suspected OSA were divided into the following 4 groups based on the apnea hypopnea index (AHI): control (AHI <5 events/hour), mild OSA (5 events/hour < AHI ≤15 events/hour), moderate OSA (15 events/hour < AHI ≤30 events/hour) and severe OSA (AHI >30 events/hour) groups. Salivary samples were collected after overnight polysomnography. Correlations between the salivary biomarkers and polysomnography parameters were analyzed. ResultsSalivary alpha-amylase levels of the moderate and severe OSA groups were significantly higher than those of the control and mild OSA groups, and no association was found between salivary cortisol and OSA severity. The salivary alpha-amylase levels were positively correlated with the AHI (r = 0.538; P < 0.01) and microarousal index (r = 0.541, P < 0.01), and negatively correlated with the lowest pulse oxygen saturation (r = −0.375, P < 0.01). Salivary cortisol levels were significantly higher in patients with hypertension than in those without hypertension (10.01 ± 2.77 ng/mL vs. 5.52 ± 1.90 ng/mL, P < 0.05), and the salivary alpha-amylase levels were highest in the OSA concomitant hypertension group (32.81 ± 11.85 U/mL). Areas under the receiver operator characteristic analysis revealed that the cutoff values of salivary alpha-amylase for identifying moderate-severe OSA and OSA concomitant hypertension were 17.64 U/mL (sensitivity 85%, specificity 91%) and 25.35 U/mL (sensitivity 70%, specificity 94%), respectively. ConclusionsSalivary alpha-amylase is positively associated with the severity of OSA and OSA concomitant hypertension.

Salivary Alpha-amylase Activity Level in ST-segment Elevation Myocardial Infarction Patients

Background and Objective: Sudden death is the main cause of mortality and disability in patients with coronary artery disease or myocardial infarction. The aim of this study was to evaluate the activity level of salivary alpha-amylase to predict malignant ventricular arrhythmias in ST-segment elevation myocardial infarction (STEMI) patients.&#x0D; Materials and Methods: In this analytical cross-sectional study, 42 patients with STEMI who referred to Imam Reza Hospital participated. First, salivary amylase was taken from all STEMI patients and then these patients were divided into two groups of patients with malignant ventricular arrhythmia or without malignant ventricular arrhythmia during 72 hours.&#x0D; Results: A total of 42 patients were included in the study out of which 30 (71.4%) were females and 12 (28.6%) males. The average salivary amylase in patients was 118/41 ± 96/87. There was no significant difference in the frequency of diabetes, blood pressure, blood lipids, ischemic heart disease, and involvement severity in both groups with arrhythmia and lack of arrhythmias (P&gt; 0.05). Also there was no significant difference in systolic and diastolic blood pressure, respiratory rate, heart rate, oxygen saturation, blood glucose, temperature and severity of infarction (P&gt; 0.05). However, the two groups were different in terms of salivary amylase levels. Salivary amylase levels were significantly higher in arrhythmic group than in the non-arrhythmic group (P&lt; 0.001).&#x0D; Conclusions: Our result shows that there is a difference in the concentrations of salivary Alpha-amylase activity level in with and without ventricular arrhythmias groups.

The Past is Present: Responses to Infant Crying Among Mothers High in Attachment Anxiety

SYNOPSISThis commentary explores potential mechanisms underlying the links between mothers’ attachment anxiety and levels of salivary alpha amylase in response to infant crying across levels of spouse support. The commentary argues that the current design cannot disentangle different explanations for the effects – whether they reflect general stress reactivity patterns or patterns occurring specifically in response to infant distress – and offers suggestions for ways in which to explore putative explanations in future studies. Understanding mechanisms is essential to identify risk factors for insensitive parenting.

The influence of Val158Met COMT on physiological stress responsivity

We tested the extent to which the catechol-O-methyltransferase (COMT) Val158Met polymorphism is associated with stress response and pain in both men and women. The participants were assessed on measures of perceived pain and state/trait anxiety in association with their COMT allele status. We also measured cortisol and salivary alpha-amylase (sAA) levels since previous research suggests an association between the COMT Val159Met polymorphism, cortisol secretion, and sAA activity. We found significant differences between methionine (Met) allele carriers and valine (Val) homozygotes following a stress manipulation in sAA levels. Met allele carriers had a stronger sAA response when compared to Val homozygotes. Furthermore, Val homozygotes showed a positive correlation between their sAA levels and trait anxiety at baseline and 20 min post-stress manipulation but displayed a negative correlation with the change in sAA levels from baseline to 20 min post-stress manipulation. Finally, state/trait anxiety was significantly correlated in Met allele carriers. These findings add support to the COMT warror/worrier model which states under stressful situations, increased dopamine levels in Val (warrior) homozygotes affords an emotional advantage relative to Met (worrier) allele carriers, who show an increased reactivity to aversive stimuli.Summary These findings offer new support for the warrior/worrier model of COMT genotype (rs4680) on human behavior. Twenty minutes following exposure to a cold stress, Val homozygotes (warrior) showed a lower biochemical stress response (salivary alpha-amylase, sAA) relative to methionine (Met) allele carriers (worrier). We further show that the COMT genotype differentially influences state and trait anxiety measures as they relate to stress responses and to each other.

Effects of Different Chair-Based Exercises on Salivary Biomarkers and Functional Autonomy in Institutionalized Older Women

ABSTRACTPurpose: The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women. Method: In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha-amylase levels were assessed before and after the intervention. Results: The CAE group improved upper and lower body strength, agility–dynamic balance, and autonomy, with fear of falling decreasing significantly (p < .05, moderate effect size). Both exercise groups showed a trend toward an increase in salivary alpha-amylase levels (CAE = 43%, d = .31, and CSE = 44%, d = .41). Conclusion: Both exercise programs were able to improve functional autonomy, even in elders older than 80 years of age. It might be interesting to investigate the effectiveness of combining both aerobic and strength exercises in a unique protocol. The modulation effect of exercise in the hormonal responses needs to be further explored.

The impact of dental anxiety on the salivary cortisol and alpha-amylase levels of children undergoing dental treatment

Background and Aim: The purpose of this study was to assess the salivary cortisol and salivary alpha-amylase levels in children aged between 6 and 9 years immediately prior to dental treatment. Methodology: A total of 183 patients aged between 6 and 9 years who were awaiting dental treatment were administered the Arabic version of the Children's fear survey – dental subscale and accordingly allocated to one of three groups: phobic patients, anxious patients, and control group. Patients' heart rate in the waiting area, salivary cortisol, and salivary amylase were compared among the groups. Results: The results of the study showed that amylase and cortisol levels had a significant association with the level of dental fear. The phobic patients had the highest levels of salivary amylase and salivary cortisol levels with no significant associations observed with either heart rate. Control and anxious patients had significantly lower amylase levels when compared to phobic patients. There was no significant difference between the salivary cortisol levels of anxious and phobic patients. Conclusions: Within the limitations of this study, we can conclude that salivary amylase is a good indicator of acute stress that can differentiate between anxiety and dental fear, while salivary cortisol is a good indicator of the phobia induced by a flight or fight response.

Relationship between Parafunctional Habits and Salivary Biomarkers.

Objectives:Parafunctional habits, as one of the etiological factors of temporomandibular disorders (TMD), are an individual’s response to increased stress. During stress and depression, biomarkers such as cortisol and salivary alpha-amylase (SAA) are secreted in the saliva. The present study aimed to investigate whether there is a correlation between salivary stress biomarkers and parafunctional habits.Materials and Methods:Thirty-two cases, from May to September 2015, were selected based on two standard stress questionnaires, namely the depression anxiety stress Scale-21 (DASS-21) and the Beck Anxiety Inventory (BAI). Saliva samples were collected to examine the level of unstimulated salivary cortisol and SAA. The significance of the results was assessed via student’s t-test and Mann-Whitney test (α=0.05).Results:The mean concentrations of cortisol and SAA in unstimulated saliva were significantly higher in the case group than in the control group (P=0.01 and 0.44, respectively). The mean scores of anxiety, stress, and depression were significantly higher in the case group than in the control group (P<0.05).Conclusion:It seems that the levels of salivary cortisol and SAA, as well as stress, anxiety, and depression scores, are higher in patients with parafunctional habits.

Basal Levels of Salivary Alpha-Amylase Are Associated with Preference for Foods High in Sugar and Anthropometric Markers of Cardiovascular Risk

Salivary alpha-amylase (sAA) influences the perception of taste and texture, features both relevant in acquiring food liking and, with time, food preference. However, no studies have yet investigated the relationship between basal activity levels of sAA and food preference. We collected saliva from 57 volunteers (63% women) who we assessed in terms of their preference for different food items. These items were grouped into four categories according to their nutritional properties: high in starch, high in sugar, high glycaemic index, and high glycaemic load. Anthropometric markers of cardiovascular risk were also calculated. Our findings suggest that sAA influences food preference and body composition in women. Regression analysis showed that basal sAA activity is inversely associated with subjective but not self-reported behavioural preference for foods high in sugar. Additionally, sAA and subjective preference are associated with anthropometric markers of cardiovascular risk. We believe that this pilot study points to this enzyme as an interesting candidate to consider among the physiological factors that modulate eating behaviour.

The forest and the trees: Examining the association of self-compassion and its positive and negative components with psychological functioning

ABSTRACTThis paper presents two studies focusing on the link between psychological functioning and self-compassion as measured by the Self-Compassion Scale (SCS), especially in terms of SCS components that represent increased compassionate and reduced uncompassionate behavior. Study One examined this association in seven domains – psychopathology, positive psychological health, emotional intelligence, self-concept, body image, motivation, and interpersonal functioning – and found that while reduced negative self-responding had a stronger link to negative emotionality and self-evaluation than positive self-responding, they were roughly equivalent predictors in other domains. Study Two examined the association of compassionate and reduced uncompassionate behavior with sympathetic nervous system and inflammatory activity after stress, and found they equally predicted salivary alpha amylase and interleukin-6 levels in individuals after a stressful situation. Overall, results suggest that both compassionate and reduced uncompassionate self-responding are central to self-compassion and that both help to explain its link to healthy psychological functioning.

The Effects of Hand Massage on Stress and Agitation Among People with Dementia in a Hospital Setting: A Pilot Study

Agitation in people with dementia is a growing concern as it causes distress for both patients and their nurses and may contribute to relational disorders. Previous studies involving patients with dementia living in long-term care facilities have reported decreased agitation following massage. The objective of this pilot study was to investigate the effect of hand massage on agitation and biological markers of stress in patients with dementia hospitalized in an acute geriatric psychiatry service. In this randomized controlled trial we included 40 agitated patients with dementia with an intervention group and a control group. The study is designed to test the effect of seven hand massages over three continuous weeks on agitation and levels of salivary cortisol (sC) and alpha-amylase (sAA). Compared to the control group, the intervention group exhibited larger increases in sC and sAA at week 1 from before to after the massage, but larger decreases at week 2 and 3, with a significant group effect for sAA at week 2. Agitation scores were not significantly different between the groups but tended to decrease more in the intervention group than the control group. This study provides first encouraging results suggesting that hand massage might have beneficial effects on stress and agitation in hospitalized patients with dementia. It also highlights the challenges associated with conducting such studies with this complex patient population. Further studies are needed to confirm these findings and the benefits of hand massage as part of routine care for patients with dementia.

Interaction Effects between the Cumulative Genetic Score and Psychosocial Stressor on Self-Reported Drinking Urge and Implicit Attentional Bias for Alcohol: A Human Laboratory Study.

The current candidate gene and environment interaction (cGxE) study examined whether the effects of an experimentally manipulated psychosocial stressor on self-reported drinking urge and implicit attentional bias for alcohol cues differ as a function of a cumulative genetic score of 5-HTTLPR, MAO-A, DRD4, DAT1 and DRD2 genotypes. The current study also examined whether salivary alpha-amylase level or self-reported anxiety state mediate these cGxE effects. Individuals with high cumulative genetic risk score of the five monoamergic genotypes showed greater attentional bias toward alcohol cues when exposed to a psychosocial stressor than when not exposed. Frequent binge-drinking Caucasian young adults (N = 105; mean age = 19; 61% male) completed both the control condition and stress condition (using the Trier Social Stress Test) in order. Regarding attentional bias, individuals with high and medium cumulative genetic risk scores showed greater attentional bias toward alcohol stimuli in the stress condition than in the control condition, whereas, those with low genetic risk scores showed greater attentional bias toward alcohol stimuli in the control condition than in the stress condition. No mediating roles of salivary alpha-amylase and anxiety state in the cGxE effect were found. Regarding self-reported drinking urge, individuals with high cumulative genetic score reported greater drinking urge than those with low genetic score regardless of experimental conditions. Although replication is necessary, the findings suggest that the association of a psychosocial stressor on implicit (but not explicit, self-reported) alcohol outcomes may differ as a function of the collective effects of five monoamine genes.

Elevated salivary alpha-amylase levels at awakening in patients with depression

BackgroundSpecific Major Depressive Disorder (MDD) biomarkers could help improve our understanding of MDD pathophysiology and aid in the refinement of current MDD criteria. While salivary cortisol (SC) can differentiate between healthy controls and patients with psychiatric disorders, salivary alpha amylase (sAA), may be a putative candidate biomarker for MDD specifically. MethodsIn a naturalistic cohort of consecutive out-patients and healthy controls, sAA and SC were determined in 833 participants (97 MDD patients, 142 patients with other mood, anxiety, and/or somatoform (MAS-) disorders, and 594 healthy controls). Samples were collected at 7 different time points (at awakening, after 30, 45, and 60 min, at 10:00 p.m., at 11:00 p.m., and at awakening on day 2). ResultsThe mean age of the sample was 43.8 years (SD = 12.9; 63.9% female). Concerning sAA, MDD patients had higher sAA levels upon awakening on two consecutive days (p = 0.04, p = 0.01 respectively), as well as a higher area under the curve with respect to the increase (AUCi; p = 0.04) in comparison to both controls and the other MAS-disorders group. Regarding SC, mean levels of evening SC were elevated in MDD patients (p = 0.049) in comparison to both controls and the other MAS-disorders group. SC values on day 2 after ingestion of dexamethasone were elevated in both MDD patients and the other MAS-disorders group (p = 0.04, p = 0.047 respectively). ConclusionssAA at awakening and not cortisol differentiates MDD from other psychiatric disorders in outpatients. This suggests that sAA may be a valuable candidate biomarker specifically for MDD.

The Effect of Thermal Comfort on Stress in Female High School Students

Background: Indoor environment, in which we are located, influences our psychological responses, like stress. Thermal comfort is one of the most important factors determining the quality of indoor environment, obtained by calculating predicted mean vote (PMV) and predicted percentage of dissatisfaction (PPD) in a steady-state approach. Several studies revealed that hot or cold temperature (°C) could increase stress. However, other climatic thermal comfort factors like relative humidity (%) and air velocity (m/s) have not been well researched in this regard. Objectives: The purpose of this study was to investigate the immediate effects of undesirable thermal comfort on stress by measuring salivary alpha-amylase levels (sAA) in female high school students. Methods: The present study was conducted in a semi-experimental design with pre-test and post-test and control group. The sample size was 390 female high school students, who were selected by multi-stage cluster random sampling, during years 2016 and 2017, in Shiraz, Iran. Students were divided to intervention and control groups. In the intervention group, thermal comfort was interfered by changing temperature, relative humidity, and air velocity for two hours. Saliva was collected by Cocorometer’s strip and sAA was measured by a hand-held device, Cocorometer (Nipro Co, Osaka, Japan). The pre-test and post-test were compared with each other. Thermal comfort in classrooms was measured by a steady-state model, PMV/PPD index, and data was analyzed by Analysis of Covariance (ANCOVA). Results: Interfering in temperatures and humidity at an average of 4.8°C and 36% for two hours in the intervention group caused thermal comfort to be in an unfavorable range (PMV > +0.5) and dissatisfaction was more than desirable (PPD > 10%). In the intervention group, when the intervention took place at the temperature, relative humidity, air velocity, and the synchronous effect of these three variables (TRHAV), the mean sAA was 43.57, 42.74, 44.23, and 45.93 (KU/L) in the pre-test and 55.91, 52.35, 44.89 and 61.99 (KU/L) in the post-test. Also, in the control group, the mean sAA was 44.73, 47.03, 43.38, and 44.36 (KU/L) in pre-test and 44.04, 47.19, 43.83, and 43.77 (KU/L) in the post-test. The sAA was significantly increased in the intervention group when thermal comfort and its climatic variables, including temperature (P < 0.001) and relative humidity (P < 0.001), was undesirable. No Significant increase was observed in air velocity (P = 0.659). In the control group, the mean sAA did not change significantly in pre-test and post-test. Conclusions: Undesirable thermal comfort increased stress in female high school students. Stress was affected by temperature, relative humidity and the synchronous effect of temperature, relative humidity, and air velocity yet not air velocity, individually.

Effects of strategic early-morning caffeine gum administration on association between salivary alpha-amylase and neurobehavioural performance during 50 h of sleep deprivation

Self-assessment is the most common method for monitoring performance and safety in the workplace. However, discrepancies between subjective and objective measures have increased interest in physiological assessment of performance. In a double-blind placebo-controlled study, 23 healthy adults were randomly assigned to either a placebo (n = 11; 5 F, 6 M) or caffeine condition (n = 12; 4 F, 8 M) while undergoing 50 h (i.e. two days) of total sleep deprivation. In previous work, higher salivary alpha-amylase (sAA) levels were associated with improved psychomotor vigilance and simulated driving performance in the placebo condition. In this follow-up article, the effects of strategic caffeine administration on the previously reported diurnal profiles of sAA and performance, and the association between sAA and neurobehavioural performance were investigated. Participants were given a 10 h baseline sleep opportunity (monitored via standard polysomnography techniques) prior to undergoing sleep deprivation (total sleep time: placebo = 8.83 ± 0.48 h; caffeine = 9.01 ± 0.48 h). During sleep deprivation, caffeine gum (200 mg) was administered at 01:00 h, 03:00 h, 05:00 h, and 07:00 h to participants in the caffeine condition (n = 12). This strategic administration of caffeine gum (200 mg) has been shown to be effective at maintaining cognitive performance during extended wakefulness. Saliva samples were collected, and psychomotor vigilance and simulated driving performance assessed at three-hour intervals throughout wakefulness. Caffeine effects on diurnal variability were compared with previously reported findings in the placebo condition (n = 11). The impact of caffeine on the circadian profile of sAA coincided with changes in neurobehavioural performance. Higher sAA levels were associated with improved performance on the psychomotor vigilance test during the first 24 h of wakefulness in the caffeine condition. However, only the association between sAA and response speed (i.e. reciprocal-transform of mean reaction time) was consistent across both days of sleep deprivation. The association between sAA and driving performance was not consistent across both days of sleep deprivation. Results show that the relationship between sAA and reciprocal-transform of mean reaction time on the psychomotor vigilance test persisted in the presence of caffeine, however the association was relatively weaker as compared with the placebo condition.

Relation between salivary cortisol and alpha amylase levels and anxiety in Egyptian patients with minor recurrent aphthous stomatitis

Background/Aim: Recurrent aphthous stomatitis (RAS) is the most prevalent ulcerative disorder of the oral mucous membrane. The aim of the present contemplate is to assess salivary cortisol (SC) and salivary alpha amylase enzyme (SAA) levels in relation to anxiety in Egyptian patients with minor recurrent aphthous stomatitis. Subjects and Methods: patients with minor RAS as a study group (RAS group, n = 35) and healthy subjects as a control (control group, n = 35) who were matching regarding age, sex, and socioeconomic state were included in this study. SC and SAA were assessed in all participants using enzyme-linked immunosorbent assay (ELISA) and kinetic enzyme assay respectively. Hamilton’s anxiety scale (HAS) has been used for evaluation of anxiety level in both study groups.Results: A significantly high mean SC (1.7 ± 0.34 μg/dl), SAA (137.87 ± 47.16 U/ml) levels and anxiety score (26.7 ± 2.21) were recorded in RAS group (p = 0.00, 0.02, 0.00) respectively in comparison to control group.Conclusion: Anxiety may have a pivotal role in etiopathogensis of RAS hence; Psychological management should be considered in RAS treatment.