Indoxyl Sulfate Induces Apoptosis and Hypertrophy in Human Kidney Proximal Tubular Cells

Indoxyl sulfate (IS) is a protein-bound uremic toxin that accumulates in patients with declining kidney function. Although generally thought of as a consequence of declining kidney function, emerging evidence demonstrates direct cytotoxic role of IS on endothelial cells and cardiomyocytes, largely through the expression of pro-inflammatory and pro-fibrotic factors. The direct toxicity of IS on human kidney proximal tubular epithelial cells (PTECs) remains a matter of debate. The current study explored the effect of IS on primary cultures of human PTECs and HK-2, an immortalized human PTEC line. Pathologically relevant concentrations of IS induced apoptosis and increased the expression of the proapoptotic molecule Bax in both cell types. IS impaired mitochondrial metabolic activity and induced cellular hypertrophy. Furthermore, statistically significant upregulation of pro-fibrotic (transforming growth factor-β, fibronectin) and pro-inflammatory molecules (interleukin-6, interleukin-8, and tumor necrosis factor-α) in response to IS was observed. Albumin had no influence on the toxicity of IS. The results of this study suggest that IS directly induced a pro-inflammatory and pro-fibrotic phenotype in proximal tubular cells. In light of the associated apoptosis, hypertrophy, and metabolic dysfunction, this study demonstrates that IS may play a role in the progression of chronic kidney disease.

The Correlates of Kidney Dysfunction – Tumour Nephrectomy Database (CKD-TUNED) Study: Protocol for a Prospective Observational Study

Background:

Tumour nephrectomy conveys a significant risk of adverse renal functional outcomes postoperatively, however there are limited strategies for predicting patients at increased risk of these outcomes. The Correlates of Kidney Dysfunction – Tumour Nephrectomy Database (CKD-TUNED) study is a prospective observational study evaluating the risk of chronic kidney disease and end-stage kidney disease in tumour nephrectomy patients.

Methods:

The CKD-TUNED study involves analysis of clinical data and collection of tissue, urine and blood samples for the purposes of forming a tissue repository resource for future investigation. Recruitment began in 2013 and is expected to continue until 2023, with a projected sample size between 700-1000 subjects.

Results:

All relevant ethics and site-specific approvals have been granted and all relevant infrastructure is in place. Study methods are undergoing validation and refinement. As of June 2017 there are 267 participants enrolled in the study.

Conclusion:

It is anticipated that this study will have the potential to identify risk factors for adverse renal functional outcomes following tumour nephrectomy, which can be used in the development of predictive models with clinical utility, and in turn improve patient outcomes.

Factors associated with acutely elevated serum creatinine following radical tumour nephrectomy: the Correlates of Kidney Dysfunction-Tumour Nephrectomy Database study

BACKGROUND

To identify factors associated with acutely elevated serum creatinine (SCr) within 7 days of radical tumour nephrectomy.

METHODS

The study population consisted of 130 consecutive patients managed for renal tumours. The primary outcome was acute kidney injury (AKI) (defined as SCr increase ≥50% above baseline), assessed using multivariable logistic regression analysis. The secondary outcome was SCr percentage increase, assessed using multivariable linear regression analysis.

RESULTS

Following nephrectomy, the mean percentage increase in SCr in the first week was 55%±29%, and 77 (59%) patients experienced AKI. Independent predictors of AKI post-nephrectomy were male gender [adjusted odds ratio (OR): 2.67; 95% confidence interval (95% CI): 1.01, 6.93], urine albumin-creatinine ratio (OR: 0.66; 95% CI: 0.47, 0.91), preoperative estimated glomerular filtration rate (eGFR) (OR: 1.03; 95% CI: 1.00, 1.05), laparoscopic nephrectomy (OR: 3.02; 95% CI: 1.00, 9.12), and non-clear cell renal cell carcinoma (RCC) (OR: 2.93; 95% CI: 1.04, 8.29). Independent predictors of a SCr increase were male gender (β: 12.0; 95% CI: 2.69, 21.3), urine albumin-creatinine ratio (β: -3.36; 95% CI: -6.55, -0.16), preoperative eGFR (β: 0.38; 95% CI: 0.10, 0.66), laparoscopic nephrectomy (β: 12.7; 95% CI: 1.05, 24.3) and obesity (β: 9.94, 95% CI: 0.61, 19.3).

CONCLUSIONS

Male gender, albuminuria, eGFR and laparoscopic nephrectomy independently associated with acutely elevated serum creatinine following radical tumour nephrectomy.

Significance of Co-expression of Epidermal Growth Factor Receptor and Ki67 on Clinical Outcome in Patients With Anal Cancer Treated With Chemoradiotherapy: An Analysis of NRG Oncology RTOG 9811

PURPOSE

To measure co-expression of EGFR and Ki67 proteins in pretreatment tumor biopsies of anal cancer patients enrolled on NRG Oncology RTOG 9811, a phase III trial comparing 5-fluorouracil/mitomycin-C/radiation therapy (Arm A) versus 5-fluorouracil/cisplatin/radiation therapy (Arm B), and to correlate expression with clinical outcome.

METHODS AND MATERIALS

EGFR and Ki67 co-expression was measured after constructing a tissue microarray using fluorescence immunohistochemistry and automated quantitative image analysis. The Ki67 score within EGFR high versus low areas (Ki67ratio in EGFRhigh:low) in each tumor core was analyzed at the median, quartiles, and as a continuous variable. Associations between the tumor markers and clinical endpoints (overall and disease-free survival, locoregional and colostomy failure, and distant metastases) were explored.

RESULTS

A total of 282 pretreatment tumors were analyzed from NRG Oncology RTOG 9811. Of evaluated specimens, 183 (65%, n=89, Arm A; n=94, Arm B) were eligible and analyzable. There were no significant differences in baseline characteristics or outcomes between analyzable and unanalyzable patient cases. Median follow-up was 6.0 years. On multivariate analysis, after adjusting for gender, patients with Ki67ratio in EGFRhigh:low ≥median had worse overall survival (hazard ratio 2.41, 95% confidence interval 1.38-4.19, P=.0019). After adjusting for N stage and largest tumor dimension, patients with Ki67ratio in EGFRhigh:low ≥ median had a higher risk of a disease-free failure (hazard ratio 1.85, 95% confidence interval 1.18-2.92, P=.0078). Technical validation with an independent anal cancer patient cohort was performed and shows a very similar biomarker score distribution.

CONCLUSIONS

High Ki67ratio in EGFRhigh:low is associated with worse clinical outcome in this subset of patients with anal cancer treated with chemoradiation on NRG Oncology RTOG 9811. Evaluation within a clinical trial will be required to determine whether patients with these tumor characteristics may specifically benefit from an EGFR-targeted therapeutic agent.

Engagement and outcomes in a digital Diabetes Prevention Program: 3-year update

OBJECTIVE

Translations of the Diabetes Prevention Program (DPP) have proliferated in recent years, with increasing expansion to digital formats. Although these DPP translations have consistently shown favorable clinical outcomes, long-term data for digital formats are limited. This study's objective was to examine clinical outcomes up to 3 years post-baseline and the relationship between program engagement and clinical outcomes in a digital DPP.

RESEARCH DESIGN AND METHODS

In a single-arm, non-randomized trial, 220 patients previously diagnosed with prediabetes were enrolled in the Omada Health Program, a commercially available, 16-week DPP-based weight loss intervention followed by an ongoing weight maintenance intervention. Changes in body weight and A1c were assessed annually. Relationships between program engagement during the first year and clinical outcomes across 3 years were examined.

RESULTS

Participants were socioeconomically diverse (62% women, 50.2% non-Hispanic white, 51.7% college educated or higher). From baseline to 3 years, those participants who completed four or more lessons and nine or more lessons achieved significant sustained weight loss (-3.0% and -2.9%, respectively) and an absolute reduction in A1c (-0.31 and -0.33, respectively) with an average remission from the prediabetes range to the normal glycemic range. Factor analysis of engagement metrics during the first year revealed two underlying dimensions, one comprising lesson completion and health behavior tracking consistency, and the other comprising website logins and group participation. When these two factors were used to predict weight loss, only the logins and group participation factor was a significant predictor of weight loss at 16 weeks and 1 year.

CONCLUSIONS

This study demonstrates significant long-term reductions in body weight and A1c in a digital DPP and identifies patterns of program engagement that predict weight loss.

Indoxyl sulphate and kidney disease: Causes, consequences and interventions

In the last decade, chronic kidney disease (CKD), defined as reduced renal function (glomerular filtration rate (GFR) < 60 mL/min per 1.73 m(2) ) and/or evidence of kidney damage (typically manifested as albuminuria) for at least 3 months, has become one of the fastest-growing public health concerns worldwide. CKD is characterized by reduced clearance and increased serum accumulation of metabolic waste products (uremic retention solutes). At least 152 uremic retention solutes have been reported. This review focuses on indoxyl sulphate (IS), a protein-bound, tryptophan-derived metabolite that is generated by intestinal micro-organisms (microbiota). Animal studies have demonstrated an association between IS accumulation and increased fibrosis, and oxidative stress. This has been mirrored by in vitro studies, many of which report cytotoxic effects in kidney proximal tubular cells following IS exposure. Clinical studies have associated IS accumulation with deleterious effects, such as kidney functional decline and adverse cardiovascular events, although causality has not been conclusively established. The aims of this review are to: (i) establish factors associated with increased serum accumulation of IS; (ii) report effects of IS accumulation in clinical studies; (iii) critique the reported effects of IS in the kidney, when administered both in vivo and in vitro; and (iv) summarize both established and hypothetical therapeutic options for reducing serum IS or antagonizing its reported downstream effects in the kidney.

Self-Monitoring and Leadership Emergence

The research described here was directed toward furthering our understanding of the antecedents of leadership emergence in groups. Kenny and Zaccaro (1983) have recently speculated that individuals who emerge as leaders may be able to perceive the needs of their group and pattern their own behavior accordingly. Past research strongly supports the notion that individuals who are high self-monitors possess skills corresponding to both these characteristics. Thus the present research examined the relationship between self-monitoring and leadership emergence in a long-term field study of natural groups. The expectation that high self-monitoring would be associated with leadership emergence received strong support. The implications of these results for furthering our understanding of the nature of self-monitoring and leadership are discussed.

Self-Monitoring and Leader Emergence

The present research seeks to further understanding of the relationship between self-monitoring and leader emergence in groups. It does so by focusing on two proposed moderators of this relationship: sex of the group members and nature of the task confronting the group. On the basis of previous research, it was hypothesized that high self-monitoring would be related to leader emergence for males, but not for females, in mixed-sex groups. Further, the relationship between self-monitoring and leader emergence was hypothesized to be stronger for a task providing minimal feedback on the task competence of group members. These hypotheses were tested in a long-term study of natural mixed-sex groups. The sex-moderator hypothesis was supported, but the task-moderator hypothesis was not. Post hoc analyses suggested that high self-monitors emerge as group leaders because they are more adaptive in their behavior than low self-monitors. Both theoretical and practical implications of the results are discussed.

A Process Investigation of Self-Monitoring and Leader Emergence

Although previous research has shown that high self-monitors tend to emerge as group leaders, little is known about the processes by which this personality trait influences leader emergence. Extrapolating from self-monitoring theory (Snyder, 1987), it was postulated that high self-monitors emerge as group leaders because they are sensitive to, and act on, social cues regarding appropriate leader style, whereas low self-monitors emerge as leaders as a function of favorable attitudes toward leadership. Two hypotheses corresponding to these postulates were tested in a laboratory experiment conducted on 68 business students assigned to 4-person problem-solving groups in an organization simulation. Both hypotheses were supported, thus showing the value of self-monitoring theory for furthering the understanding of leader emergence within groups. The implications of these findings for selfmonitoring theory, as well as for the measurement and development of organization leadership, are explored.

Validating Objective Versus Subjective Judgments

Perceivers' interest in social comparison and consistency information for assessing the accuracy of a personal judgment was investigated. Prior to their judging a photograph of a woman, male subjects' perceptions of the causal locus of beauty were manipulated. Subjects were told they would rate the woman again and were asked how interested they were before making their second judgment in seeing (a) additional photographs of the woman (consistency information) and (b) other male subjects' ratings of the woman's attractiveness (consensus or social comparison information). Subjects expressed greater interest in consistency than consensus information. Subjects were more interested in consensus information when they saw beauty as objective than when they saw beauty as subjective. Implications of these results for social comparison theory are discussed.

Self-Monitoring and Leadership Emergence in Groups

The research described here was directed toward furthering our understanding of the antecedents of leadership emergence in groups. In particular, it sought to identify important personality characteristics associated with this phenomenon. Kenny and Zaccaro (1983) have recently speculated that individuals who emerge as leaders may be able to perceive the needs of the group and pattern their own behavior accordingly. Past research strongly supports the notion that individuals who are high in the personality dimension of self-monitoring possess skills corresponding to both these characteristics. The present research examined the effects of self-monitoring on leadership emergence in a study of natural groups. The expectation that high self-monitoring would be associated with leadership emergence was strongly supported for male participants. The implications of these results for increasing our knowledge of the nature of self-monitoring and leadership were discussed.

Brain connectivity reflects human aesthetic responses to music

Humans uniquely appreciate aesthetics, experiencing pleasurable responses to complex stimuli that confer no clear intrinsic value for survival. However, substantial variability exists in the frequency and specificity of aesthetic responses. While pleasure from aesthetics is attributed to the neural circuitry for reward, what accounts for individual differences in aesthetic reward sensitivity remains unclear. Using a combination of survey data, behavioral and psychophysiological measures and diffusion tensor imaging, we found that white matter connectivity between sensory processing areas in the superior temporal gyrus and emotional and social processing areas in the insula and medial prefrontal cortex explains individual differences in reward sensitivity to music. Our findings provide the first evidence for a neural basis of individual differences in sensory access to the reward system, and suggest that social-emotional communication through the auditory channel may offer an evolutionary basis for music making as an aesthetically rewarding function in humans.

Two-week test-retest reliability of the Polar® RS800CX™ to record heart rate variability

Recently, research has validated the use of Polar^® heart rate monitors as a tool to index heart rate variability (HRV). In the current investigation, we sought to evaluate the test-retest reliability of both time and frequency domain measures of HRV using the Polar^® RS800CX^™ . Continuous HRV data were collected as 60 nominally healthy adults underwent a resting and orthostatic stress test. We evaluated reproducibility by means of the interclass correlation coefficient for absolute agreement and consistency, and the standard error of measurement. We found moderate reliable 2-week test-retest reliability of HRV using the Polar^® RS800CX^™ , results that are in line with previous studies that have validated the stability of HRV using other methods of measurement (e.g. electrocardiogram). Additionally, when examining different methods of spectral density estimation, we found that using the auto-regressive transformation method provides the most stable indices of HRV. Taken together, our results suggest that the Polar^® RS800CX^™ is not only a valid method to record HRV, but also a reliable one, particularly when using the auto-regressive transformation method.

Pneumogastric (Vagus) Nerve Activity Indexed by Heart Rate Variability in Chronic Pain Patients Compared to Healthy Controls: A Systematic Review and Meta-Analysis

BACKGROUND

A large body of scientific literature derived from experimental studies emphasizes the vital role of vagal-nociceptive networks in acute pain processing. However, research on vagal activity, indexed by vagally-mediated heart rate variability (vmHRV) in chronic pain patients (CPPs), has not yet been summarized.

OBJECTIVES

To systematically investigate differences in vagus nerve activity indexed by time- and frequency-domain measures of vmHRV in CPPs compared to healthy controls (HCs).

STUDY DESIGN

A systematic review and meta-analysis, including meta-regression on a variety of populations (i.e., clinical etiology) and study-level (i.e., length of HRV recording) covariates.

SETTING

Not applicable (variety of studies included in the meta-analysis).

METHODS

Eight computerized databases (PubMed via MEDLINE, PsycNET, PsycINFO, Embase, CINAHL, Web of Science, PSYNDEX, and the Cochrane Library) in addition to a hand search were systematically screened for eligible studies based on pre-defined inclusion criteria. A meta-analysis on all empirical investigations reporting short- and long-term recordings of continuous time- (root-mean-square of successive R-R-interval differences [RMSSD]) and frequency-domain measures (high-frequency [HF] HRV) of vmHRV in CPPs and HCs was performed. True effect estimates as adjusted standardized mean differences (SMD; Hedges g) combined with inverse variance weights using a random effects model were computed.

RESULTS

CPPs show lower vmHRV than HCs indexed by RMSSD (Z = 5.47, P < .0001; g = -0.24;95% CI [-0.33, -0.16]; k = 25) and HF (Z = 4.54, P < .0001; g = -0.30; 95% CI [-0.44, -0.17]; k = 61).Meta-regression on covariates revealed significant differences by clinical etiology, age, gender, and length of HRV recording.

LIMITATIONS

We did not control for other potential covariates (i.e., duration of chronic pain, medication intake) which may carry potential risk of bias.

CONCLUSION(S)

The present meta-analysis is the most extensive review of the current evidence on vagal activity indexed by vmHRV in CPPs. CPPs were shown to have lower vagal activity, indexed by vmHRV, compared to HCs. Several covariates in this relationship have been identified. Further research is needed to investigate vagal activity in CPPs, in particular prospective and longitudinal follow-up studies are encouraged.

A Validated Smartphone-Based Assessment of Gait and Gait Variability in Parkinson's Disease

Background

A well-established connection exists between increased gait variability and greater fall likelihood in Parkinson’s disease (PD); however, a portable, validated means of quantifying gait variability (and testing the efficacy of any intervention) remains lacking. Furthermore, although rhythmic auditory cueing continues to receive attention as a promising gait therapy for PD, its widespread delivery remains bottlenecked. The present paper describes a smartphone-based mobile application (“SmartMOVE”) to address both needs.

Methods

The accuracy of smartphone-based gait analysis (utilizing the smartphone’s built-in tri-axial accelerometer and gyroscope to calculate successive step times and step lengths) was validated against two heel contact–based measurement devices: heel-mounted footswitch sensors (to capture step times) and an instrumented pressure sensor mat (to capture step lengths). 12 PD patients and 12 age-matched healthy controls walked along a 26-m path during self-paced and metronome-cued conditions, with all three devices recording simultaneously.

Results

Four outcome measures of gait and gait variability were calculated. Mixed-factorial analysis of variance revealed several instances in which between-group differences (e.g., increased gait variability in PD patients relative to healthy controls) yielded medium-to-large effect sizes (eta-squared values), and cueing-mediated changes (e.g., decreased gait variability when PD patients walked with auditory cues) yielded small-to-medium effect sizes—while at the same time, device-related measurement error yielded small-to-negligible effect sizes.

Conclusion

These findings highlight specific opportunities for smartphone-based gait analysis to serve as an alternative to conventional gait analysis methods (e.g., footswitch systems or sensor-embedded walkways), particularly when those methods are cost-prohibitive, cumbersome, or inconvenient.

Quantifying auditory temporal stability in a large database of recorded music

“Moving to the beat” is both one of the most basic and one of the most profound means by which humans (and a few other species) interact with music. Computer algorithms that detect the precise temporal location of beats (i.e., pulses of musical “energy”) in recorded music have important practical applications, such as the creation of playlists with a particular tempo for rehabilitation (e.g., rhythmic gait training), exercise (e.g., jogging), or entertainment (e.g., continuous dance mixes). Although several such algorithms return simple point estimates of an audio file’s temporal structure (e.g., “average tempo”, “time signature”), none has sought to quantify the temporal stability of a series of detected beats. Such a method-a “Balanced Evaluation of Auditory Temporal Stability” (BEATS)–is proposed here, and is illustrated using the Million Song Dataset (a collection of audio features and music metadata for nearly one million audio files). A publically accessible web interface is also presented, which combines the thresholdable statistics of BEATS with queryable metadata terms, fostering potential avenues of research and facilitating the creation of highly personalized music playlists for clinical or recreational applications.

Brain morphometric correlates of metabolic variables in HIV: the CHARTER study

Obesity and other metabolic variables are associated with abnormal brain structural volumes and cognitive dysfunction in HIV-uninfected populations. Since individuals with HIV infection on combined antiretroviral therapy (CART) often have systemic metabolic abnormalities and changes in brain morphology and function, we examined associations among brain volumes and metabolic factors in the multisite CNS HIV AntiRetroviral Therapy Effects Research (CHARTER) cohort, cross-sectional study of 222 HIV-infected individuals. Metabolic variables included body mass index (BMI), total blood cholesterol (C), low- and high-density lipoprotein C (LDL-C and HDL-C), blood pressure, random blood glucose, and diabetes. MRI measured volumes of cerebral white matter, abnormal white matter, cortical and subcortical gray matter, and ventricular and sulcal CSF. Multiple linear regression models allowed us to examine metabolic variables separately and in combination to predict each regional volume. Greater BMI was associated with smaller cortical gray and larger white matter volumes. Higher total cholesterol (C) levels were associated with smaller cortex volumes; higher LDL-C was associated with larger cerebral white matter volumes, while higher HDL-C levels were associated with larger sulci. Higher blood glucose levels and diabetes were associated with more abnormal white matter. Multiple atherogenic metabolic factors contribute to regional brain volumes in HIV-infected, CART-treated patients, reflecting associations similar to those found in HIV-uninfected individuals. These risk factors may accelerate cerebral atherosclerosis and consequent brain alterations and cognitive dysfunction.

Body mass index is related to autonomic nervous system activity as measured by heart rate variability--a replication using short term measurements

OBJECTIVES

The present analysis is a replication of previous findings presenting first evidence of an association between body mass index (BMI) and autonomic nervous system (ANS) activity as measured by heart rate variability (HRV), in healthy non-obese adults.

DESIGN

A total of fifty-nine apparently healthy male (M) and female (F) individuals (M/F = 15/44) were included in the trial. HRV data for analysis was derived from 5 minutes of baseline recordings, while the subject was sitting on a comfortable chair. Subjects' body measures (weight and height) were taken and BMI was obtained according to common calculation (kg/m²).

RESULTS

BMI was inversely related to pNN50 and RMSSD components of HRV. Statistically significant differences between stratified groups (BMI<20, BMI 20-25, BMI >25) only occurred for analysis of pNN50 components. The pNN50 components and RMSSD are strongly associated with cardiac vagal influence, and thus represents parasympathetic activity.

CONCLUSIONS

The present data supports previous findings, that sympatho-vagal balance is related to BMI in non-obese, healthy individuals, providing evidence for a prominent role of the vagus nerve in the modulation of the energy expenditure of the human organism. Furthermore, this relation can be observed in short term recordings of HRV of 5 minutes in length.

Development of a time-stepping sediment budget model for assessing land use impacts in large river basins

The use of river basin modelling to guide mitigation of non-point source pollution of wetlands, estuaries and coastal waters has become widespread. To assess and simulate the impacts of alternate land use or climate scenarios on river washload requires modelling techniques that represent sediment sources and transport at the time scales of system response. Building on the mean-annual SedNet model, we propose a new D-SedNet model which constructs daily budgets of fine sediment sources, transport and deposition for each link in a river network. Erosion rates (hillslope, gully and streambank erosion) and fine sediment sinks (floodplains and reservoirs) are disaggregated from mean annual rates based on daily rainfall and runoff. The model is evaluated in the Burdekin basin in tropical Australia, where policy targets have been set for reducing sediment and nutrient loads to the Great Barrier Reef (GBR) lagoon from grazing and cropping land. D-SedNet predicted annual loads with similar performance to that of a sediment rating curve calibrated to monitored suspended sediment concentrations. Relative to a 22-year reference load time series at the basin outlet derived from a dynamic general additive model based on monitoring data, D-SedNet had a median absolute error of 68% compared with 112% for the rating curve. RMS error was slightly higher for D-SedNet than for the rating curve due to large relative errors on small loads in several drought years. This accuracy is similar to existing agricultural system models used in arable or humid environments. Predicted river loads were sensitive to ground vegetation cover. We conclude that the river network sediment budget model provides some capacity for predicting load time-series independent of monitoring data in ungauged basins, and for evaluating the impact of land management on river sediment load time-series, which is challenging across large regions in data-poor environments.

The effect of anxiety on heart rate variability, depression, and sleep in chronic obstructive pulmonary disease

OBJECTIVES

The current study investigates heart rate variability (HRV) responses to a psychosocial stressor in chronic obstructive pulmonary disease (COPD) patients, and the potential role of anxiety as a confounding factor in this relationship. Additionally, this study also investigates the influence of anxiety on sleep and depressive symptoms among COPD patients.

METHODS

The study utilized a 2 (disease status)×2 (anxiety group) factorial design examining HRV associated with anxiety symptoms and COPD during a standardized acute social stress task. Participants (mean age 59.1±11.2 years; 50% female) completed pulmonary function testing, HRV monitoring, and self-report questionnaires assessing psychological factors. 30 COPD patients were age- and gender-matched with 30 healthy controls.

RESULTS

HRV response to a psychosocial stressor among participants with higher anxiety (both COPD and healthy) reflected autonomic dysregulation in both time and frequency domains that was not evident among non-anxious participants. COPD participants with higher anxiety reported greater symptoms of depression and poorer sleep quality than did COPD participants with low anxiety.

CONCLUSIONS

Anxiety is associated with dysregulated HRV response to a psychosocial stressor, but the negative influence of anxiety and COPD on autonomic function did not appear to be additive. Comorbid anxiety in patients with COPD is associated with increased behavioral and psychological symptoms of distress.