Salivary biomarkers of HPA axis and autonomic activity in adults with intellectual disability with and without stereotyped and self-injurious behavior disorders

Relationship between serum cortisol levels, stereotypies, and the presence of autism spectrum disorder in patients with severe intellectual disability

Stereotypies are one of the diagnostic criteria for autism spectrum disorder (ASD) and are common to both ASD and intellectual disability (ID). Previous studies have been inconclusive, with some showing a positive correlation between stereotypies and cortisol, while others have shown a negative correlation. We hypothesised and investigated the presence of ASD as one of the variables involved in this discrepancy. We tested the following hypotheses on serum cortisol in a total of 84 hospitalised patients with severe ID and ASD with severe ID. Hypothesis (1) Higher levels of stereotypies are associated with higher levels of serum cortisol. Hypothesis (2) The presence of ASD will moderate the association between stereotypies and high serum cortisol levels. The results of the analysis supported hypotheses (1) and (2). We also found that in the population with ID, serum cortisol levels were significantly lower in the ASD group compared to the non-ASD group. The present findings that the association between stereotypies and serum cortisol levels in people with severe ID is moderated by the presence of ASD suggest that the stress response system may function differently in people with ID and ASD than in the general population.

Hair Cortisol and Self-Injurious Behavior Among Children With Autism Spectrum Disorder

Elevated salivary cortisol levels have been documented in individuals who engage in self-injurious behavior (SIB), indicating acute physiological stress. Less is known about the chronicity of stress and SIB. We analyzed the relationship between parent ratings of problem behavior and hair cortisol concentrations (an index of chronic adrenocortical activity) in 23 children with autism spectrum disorder (ASD). Parent ratings of problem behavior were not significantly correlated with hair cortisol concentrations. When children were categorized into groups based on the frequency and severity of SIB, participants with the greatest frequency and severity of SIB had higher hair cortisol concentrations compared to children without SIB. Frequent and severe SIB may be associated with altered hypothalamic-pituitary-adrenal (HPA) axis activity in children with ASD.

microRNAs and Gene-Environment Interactions in Autism: Effects of Prenatal Maternal Stress and the SERT Gene on Maternal microRNA Expression

Background: Genetics and environment both are critical in autism spectrum disorder (ASD), but their interaction (G × E) is less understood. Numerous studies have shown higher incidence of stress exposures during pregnancies with children later diagnosed with ASD. However, many stress-exposed mothers have unaffected children. The serotonin transporter (SERT) gene affects stress reactivity. Two independent samples have shown that the association between maternal stress exposure and ASD is greatest with maternal presence of the SERT short (S)-allele (deletion in the promoter region). MicroRNAs play a regulatory role in the serotonergic pathway and in prenatal stress and are therefore potential mechanistic targets in this setting. Design/methods: We profiled microRNA expression in blood from mothers of children with ASD, with known stress exposure during pregnancy. Samples were divided into groups based on SERT genotypes (LL/LS/SS) and prenatal stress level (high/low). Results: Two thousand five hundred mature microRNAs were examined. The ANOVA analysis showed differential expression (DE) of 119 microRNAs; 90 were DE in high- vs. low-stress groups (stress-dependent). Two (miR-1224-5p, miR-331-3p) were recently reported by our group to exhibit stress-dependent expression in rodent brain samples from embryos exposed to prenatal stress. Another, miR-145-5p, is associated with maternal stress. Across SERT genotypes, with high stress exposure, 20 significantly DE microRNAs were detected, five were stress-dependent. These microRNAs may be candidates for stress × SERT genotype interactions. This is remarkable as these changes were from mothers several years after stress-exposed pregnancies. Conclusions: Our study provides evidence for epigenetic alterations in relation to a G × E model (prenatal maternal stress × SERT gene) in ASD.

Proopiomelanocortin (POMC) sequencing and developmental delay: Preliminary evidence for a SNP in the 3' UTR region of the POMC gene-Possible relevance for biological risk and self-injurious behavior

The proopiomelanocortin (POMC) molecule has been implicated in models of self-injurious behavior (SIB) in neurodevelopmental disorders, but it has never been specifically sequenced in search of base specific polymorphisms. The empirical focus of this preliminary study was to sequence the POMC gene in 11 children (mean age = 41.8 months, range = 12-60 months; 73% male) with clinical concerns regarding global developmental delay, 5 with reported self-injury. Genomic DNA was extracted from blood samples, and the POMC gene was amplified by specific oligonucleotide primers via polymerase chain reaction. The amplified gene products were sequenced by the University of Minnesota Genomic Center, and the results were analyzed using Sequencher software. A single nucleotide polymorphism (SNP), 1130 C>T, was found in the 3' untranslated region (UTR) of two samples (one of whom had SIB). The program TargetScanHuman was used to predict the function of this mutation. Variant c.1130 C<T was predicted to be located in the target site of two microRNAs (miRNAs; hsa-mir-3715 and hsa-mir-1909), and the variant allele T may result in an increased minimum free energy for the two miRNAs. Further work with much larger samples is needed to continue the investigation of POMC's possible function as a risk factor for the development of SIB in children with developmental delay/disability. The findings presented in this study show that the SNP found in the 3' UTR could alter the binding of miRNAs to POMC 3'UTR, thus, increasing POMC expression and affecting several biological systems with high relevance to the biology of self-injury. There was a significant difference in β-endorphin levels between SIB (M = 169.25 pg/mL) and no SIB (M = 273.5 pg/mL, SD = 15.2) cases (p < .01). Intervention implications are tied to prior observations of individual differences among SIB responders and nonresponders to treatment with the opioid antagonist naltrexone. Stratifying individuals with SIB by POMC mutation status may provide a potential tailoring-like variable to guide the selection of who is more (or less) likely to respond to opiate antagonist treatment. Currently, opioid antagonistic treatment for SIB is empiric (trial and error).

Possible Link Between Stress-related Factors and Altered Body Composition in Women with Polycystic Ovarian Syndrome

Background

Stress is an invisible factor affecting modern day living and is strongly associated with many disease pathogenesis including polycystic ovarian syndrome (PCOS) in women. PCOS is the most frequent endocrinological disorder that affects women of reproductive age, leading to metabolic dysfunction and body composition alterations. Salivary amylase and cortisol are major stress mediators that have been implicated in PCOS. However, their role in altering body composition in PCOS is yet to be deciphered.

Aim

The present study aimed at understanding the relation between stress-associated factors and alterations in body composition among PCOS patients.

Design

This study enrolled a total of 100 patients (PCOS) and 60 age-matched controls. The female patients were of ages between 13 and 30 years.

Materials and Methods

Standard assay kits were used to evaluate the α-amylase activity and cortisol level in saliva. The participants were chosen on the basis of the Rotterdam American Society for Reproductive Medicine/European Society of Human Reproduction criteria. Saliva was collected from each participant as per the protocol of Salimetrics, USA.

Statistical Analysis

Statistical analysis was performed using SPSS version 20 for Windows. The quantitative variables are described as mean ± standard deviation. P < 0.05 was considered significant.

Results

Increased salivary cortisol level and α-amylase activity were seen in the PCOS population as compared to age-matched controls suggesting patients a sustained stress scenario in their system. Moreover, overweight PCOS participants reflected higher amylase activity than the lean patients participants. Pulse rate, body mass index (BMI), visceral adiposity, and waist-hip ratio (WHR) was considerably higher in the PCOS patients participants compared to controls. A significant correlation could be drawn between the α-amylase activity and BMI or WHR, respectively, among PCOS patients. These observations indicate a strong link between the stress marker and alterations in the body composition parameters of PCOS patients participants.

Conclusion

Higher prevalence of stress in PCOS patients participants has a critical role in their altered body composition.

Hypothalamic-pituitary-adrenal (HPA) axis activity in adults with intellectual disabilities: a preliminary investigation

BACKGROUND

Cortisol is a marker of physiological arousal, exhibiting a characteristic pattern of diurnal activity. The daily cortisol profile has been xamined extensively and is atypical in a number of clinical disorders. However, there are very few studies focussing on the cortisol profile in adults with intellectual disabilities (ID). This paper reports a preliminary investigation into the nature of the cortisol profile in adults with mild or moderate ID and provides reflections on the challenges of psychophysiological research in this population.

METHODS

On two consecutive days, 39 adults with mild or moderate ID each donated saliva samples for cortisol analysis, at multiple times between waking and evening. A comparison between these data and the published literature permitted a descriptive assessment of the cortisol awakening response (CAR) and diurnal profile. A variety of psychometric measures and an assessment of behavioural history were also collected in order to describe aspects of the participants' emotional and behavioural states.

RESULTS

Individuals with ID exhibit a diurnal cortisol secretion profile, qualitatively similar to that of the typical, healthy, adult population. However, the findings also suggested a blunted CAR, warranting further investigation. There was also some evidence that cortisol secretion was affected by anxiety and a recent history of aggression.

CONCLUSION

While further work is required to characterise the CAR fully, there was no indication that the diurnal cortisol profile among people with ID differs from that of the typical population. This study also demonstrates that, although challenging, it is feasible, and acceptable to participants, to collect repeated physiological measures from men and women with mild and moderate ID.

Repetitive and self-injurious behaviors: associations with caudate volume in autism and fragile X syndrome

Background

Following from previous work suggesting that neurobehavioral features distinguish fragile X and idiopathic variants of autism, we investigated the relationships between four forms of repetitive behavior (stereotypy, self-injury, compulsivity, ritual behavior) and caudate nuclei volume in two groups: boys with fragile X syndrome, a subset of whom met criteria for autism, and a comparison group of boys with idiopathic autism.

Methods

Bilateral caudate nuclei volumes were measured in boys aged 3 to 6 years with fragile X syndrome (n = 41), the subset of boys with fragile X syndrome and autism (n = 16), and boys with idiopathic autism (n = 30). Repetitive behaviors were measured using the Repetitive Behavior Scales-Revised.

Results

For boys with idiopathic autism, left caudate volume was modestly associated with self-injury, while both compulsive and ritual behaviors showed significant positive correlations with bilateral caudate nuclei volumes, replicating previous results. For boys with fragile X syndrome, there was no such association between caudate volume and compulsive behaviors. However, we did identify significant positive correlations between self-injury total scores and number of self-injury topographies with bilateral caudate nuclei volumes.

Conclusions

These findings suggest a specific role for the caudate nucleus in the early pathogenesis of self-injurious behavior associated with both idiopathic autism and fragile X syndrome. Results further indicate that the caudate may be differentially associated with compulsive behavior, highlighting the utility of isolating discrete brain-behavior associations within and between subtypes of autism spectrum disorder.

Recent research on aetiology, development and phenomenology of self-injurious behaviour in people with intellectual disabilities: a systematic review and implications for treatment

BACKGROUND

Behavioural interventions conceptualise self-injurious behaviour (SIB) as developing from early repetitive behaviours through acquisition of homeostatic functions in regulating stimulation and subsequent shaping into SIB through socially mediated or automatic operant reinforcement. Despite high success rates, such interventions rarely completely eliminate SIB, and overall effectiveness has not increased since the 1960s.

METHODS

Research (excluding studies of single genetic syndromes) on the early development, functional properties and phenomenology of SIB in persons with intellectual disabilities (IDs) published from 1999 to 2010 inclusive is reviewed.

RESULTS

Despite evidence to support the operant shaping hypothesis, in some cases tissue-damaging SIB, especially head-banging, emerges at a similar or younger age than stereotyped behaviours or 'proto-SIB', often associated with tantrums following frustrative non-reward and/or abrupt situational transitions. Many young children show undifferentiated patterns of responding in functional analyses of SIB, and SIB is associated with aggression and impulsivity as well as with repetitive behaviour.

CONCLUSIONS

One dynamic in the development of SIB may be Pavlovian conditioning of aggression, originally elicited by aversive events or frustrative non-reward, to stimuli associated with such situations. Integration into operant technology of interventions based on Pavlovian principles such as graduated exposure (with or without counterconditioning) to aversive stimuli may enhance the effectiveness of behavioural interventions.