Anita van Zwieten

BACKGROUND: Polyvagal theory emphasizes that autonomic nervous system functioning plays a key role in social behavior and emotion. The theory predicts that psychiatric disorders of social dysfunction are associated with reduced heart rate variability, an index of autonomic control, as well as social inhibition and avoidance. The purpose of this study was to examine whether heart rate variability was reduced in treatment-seeking patients diagnosed with social anxiety disorder, a disorder characterized by social fear and avoidance. METHODS: Social anxiety patients (n = 53) were recruited prior to receiving psychological therapy. Healthy volunteers were recruited through the University of Sydney and the general community and were matched by gender and age (n = 53). Heart rate variability was assessed during a five-minute recording at rest, with participants completing a range of self-report clinical symptom measures. RESULTS: Compared to controls, participants with social anxiety exhibited significant reductions across a number of heart rate variability measures. Reductions in heart rate variability were observed in females with social anxiety, compared to female controls, and in patients taking psychotropic medication compared to non-medicated patients. Finally, within the clinical group, we observed significant associations between reduced heart rate variability and increased social interaction anxiety, psychological distress, and harmful alcohol use. CONCLUSIONS: The results of this study confirm that social anxiety disorder is associated with reduced heart rate variability. Resting state heart rate variability may therefore be considered a marker for social approach-related motivation and capacity for social engagement. Additionally, heart rate variability may provide a useful biomarker to explain underlying difficulties with social approach, impaired stress regulation, and behavioral inhibition, especially in disorders associated with significant impairments in these domains.

Background and objectives Poor cognition can affect educational attainment, but the extent of neurocognitive impairment in children with CKD is not well understood. This systematic review assessed global and domain-specific cognition and academic skills in children with CKD and whether these outcomes varied with CKD stage. Design, setting, participants, & measurements Electronic databases were searched for observational studies of children with CKD ages 21 years old or younger that assessed neurocognitive or educational outcomes. Risk of bias was assessed using a modified Newcastle–Ottawa scale. We used random effects models and expressed the estimates as mean differences with 95% confidence intervals stratified by CKD stage. Results Thirty-four studies (25 cross-sectional, n =2095; nine cohort, n =991) were included. The overall risk of bias was high because of selection and measurement biases. The global cognition (full-scale intelligence quotient) of children with CKD was classified as low average. Compared with the general population, the mean differences (95% confidence intervals) in full-scale intelligence quotient were −10.5 (95% confidence interval, −13.2 to −7.72; all CKD stages, n =758), −9.39 (95% confidence interval, −12.6 to −6.18; mild to moderate stage CKD, n =582), −16.2 (95% confidence interval, −33.2 to 0.86; dialysis, n =23), and −11.2 (95% confidence interval, −17.8 to −4.50; transplant, n =153). Direct comparisons showed that children with mild to moderate stage CKD and kidney transplants scored 11.2 (95% confidence interval, 2.98 to 19.4) and 10.1 (95% confidence interval, −1.81 to 22.0) full-scale intelligence quotient points higher than children on dialysis. Children with CKD also had lower scores than the general population in executive function and memory (verbal and visual) domains. Compared with children without CKD, the mean differences in academic skills ( n =518) ranged from −15.7 to −1.22 for mathematics, from −9.04 to −0.17 for reading, and from −14.2 to 2.53 for spelling. Conclusions Children with CKD may have low-average cognition compared with the general population, with mild deficits observed across academic skills, executive function, and visual and verbal memory. Limited evidence suggests that children on dialysis may be at greatest risk compared with children with mild to moderate stage CKD and transplant recipients.

OBJECTIVE: The aim was to compare quality of life (QoL) among children and adolescents with different stages of chronic kidney disease (CKD) and determine factors associated with changes in QoL. DESIGN: Cross-sectional. SETTING: The Kids with CKD study involved five of eight paediatric nephrology units in Australia and New Zealand. PATIENTS: There were 375 children and adolescents (aged 6-18 years) with CKD, on dialysis or transplanted, recruited between 2013 and 2016. MAIN OUTCOME MEASURES: Overall and domain-specific QoL were measured using the Health Utilities Index 3 score, with a scale from -0.36 (worse than dead) to 1 (perfect health). QoL scores were compared between CKD stages using the Mann-Whitney U test. Factors associated with changes in QoL were assessed using multivariable linear and ordinal logistic regression. RESULTS: QoL for those with CKD stages 1-2 (n=106, median 0.88, IQR 0.63-0.96) was higher than those on dialysis (n=43, median 0.67, IQR 0.39-0.91, p<0.001), and similar to those with kidney transplants (n=135, median 0.83, IQR 0.59-0.97, p=0.4) or CKD stages 3-5 (n=91, 0.85, IQR 0.60-0.98). Reductions were most frequent in the domains of cognition (50%), pain (42%) and emotion (40%). The risk factors associated with decrements in overall QoL were being on dialysis (decrement of 0.13, 95% CI 0.02 to 0.25, p=0.02), lower family income (decrement of 0.10, 95% CI 0.03 to 0.15, p=0.002) and short stature (decrement of 0.09, 95% CI 0.01 to 0.16, p=0.02). CONCLUSIONS: The overall QoL and domains such as pain and emotion are substantially worse in children on dialysis compared with earlier stage CKD and those with kidney transplants.