The role of preterm birth in stress-induced sodium excretion in young adults

BACKGROUND

Early-life programming due to prematurity and very low birth weight (VLBW, <1500 g) is believed to contribute to development of hypertension, but the mechanisms remain unclear. Experimental data suggest that altered pressure natriuresis (increased renal perfusion pressure promoting sodium excretion) may be a contributing mechanism. We hypothesize that young adults born preterm will have a blunted pressure natriuresis response to mental stress compared with those born term.

METHODS

In this prospective cohort study of 190 individuals aged 18-23 years, 156 born preterm with VLBW and 34 controls born term with birth weight at least 2500 g, we measured urine sodium/creatinine before and after a mental stress test and continuous blood pressure before and during the stress test. Participants were stratified into groups by the trajectory at which mean arterial pressure (MAP) increased following the test. The group with the lowest MAP trajectory was the reference group. We used generalized linear models to assess poststress urine sodium/creatinine relative to the change in MAP trajectory and assessed the difference between groups by preterm birth status.

RESULTS

Participants' mean age was 19.8 years and 57% were women. Change in urine sodium/creatinine per unit increase in MAP when comparing middle trajectory group against the reference group was greater in those born preterm [β 5.4%, 95% confidence interval (95% CI) -11.4 to 5.3] than those born term (β 38.5%, 95% CI -0.04 to 92.0), interaction term P = 0.002.

CONCLUSION

We observed that, as blood pressure increased following mental stress, young adults born preterm exhibited decreased sodium excretion relative to term-born individuals.

Risk of Obesity and Unhealthy Central Adiposity in Adolescents Born Preterm With Very Low Birthweight Compared to Term-Born Peers

Background: Early-life factors such as preterm birth or very low birthweight (VLBW) are associated with increased cardiovascular disease risk. However, it remains unknown whether this is due to an increased risk of obesity (unhealthy central adiposity) because studies have predominantly defined obesity based on BMI, an imprecise adiposity measure. Objective: Investigate if adolescents born preterm with VLBW have a higher risk of unhealthy central adiposity compared to term-born peers. Study Design: Cross-sectional analysis of data from a prospective cohort study of 177 individuals born preterm with VLBW (<1500 g) and 51 term-born peers (birthweight ≥2500 g). Individuals with congenital anomalies, genetic syndromes, or major health conditions were excluded. Height, weight, waist circumference, skin fold thickness, and dual energy X-ray absorptiometry body composition were measured at age 14 years. We calculated BMI percentiles and defined overweight/obesity as BMI ≥85th percentile for age and sex. We estimated the preterm-term differences in overweight/obesity prevalence and adiposity distribution with multivariable generalized linear models. Results: There was no difference in small for gestational age status or overweight/obesity prevalence. Compared to term, youth born preterm with VLBW had lower BMI z-score [β -0.38, 95% confidence limits (CL) -0.75 to -0.02] but no differences in adiposity apart from subscapular-to-triceps ratio (STR; β 0.18, 95% CL 0.08 to 0.28). Conclusions: Adolescents born preterm with VLBW had smaller body size than their term-born peers and had no differences in central adiposity except greater STR.

Duration of Simultaneous Exposure to High-Risk and Lower-Risk Nephrotoxic Antimicrobials in the Neonatal Intensive Care Unit (NICU) and Future Adolescent Kidney Health

OBJECTIVE

To determine whether greater duration of simultaneous exposure to antimicrobials with high nephrotoxicity risk combined with lower-risk antimicrobials (simultaneous exposure) in the neonatal intensive care unit (NICU) is associated with worse later kidney health in adolescents born preterm with very low birth weight (VLBW).

STUDY DESIGN

Prospective cohort study of participants born preterm with VLBW (<1500 g) as singletons between January 1, 1992, and June 30, 1996. We defined simultaneous exposure as a high-risk antimicrobial, such as vancomycin, administered with a lower-risk antimicrobial on the same date in the NICU. Outcomes were serum creatinine, estimated glomerular filtration rate (eGFR), and first-morning urine albumin-creatinine ratio (ACR) at age 14 years. We fit multivariable linear regression models with days of simultaneous exposure and days of nonsimultaneous exposure as main effects, adjusting for gestational age, birth weight, and birth weight z-score.

RESULTS

Of the 147 out of 177 participants who had exposure data, 97% received simultaneous antimicrobials for mean duration 7.2 days (SD 5.6). No participant had eGFR <90 ml/min/1.73 m2. The mean ACR was 15.2 mg/g (SD 38.7) and 7% had albuminuria (ACR >30 mg/g). Each day of simultaneous exposure was associated only with a 1.04-mg/g higher ACR (95% CI 1.01 to 1.06).

CONCLUSIONS

Despite frequent simultaneous exposure to high-risk combined with lower-risk nephrotoxic antimicrobials in the NICU, there were no clinically relevant associations with worse kidney health identified in adolescence. Although future studies are needed, these findings may provide reassurance in a population thought to be at increased risk of chronic kidney disease.

Effect of liquid and solid test meals on symptoms and gastric myoelectrical activity in patients with gastroparesis and functional dyspepsia

BACKGROUND

Patients with gastroparesis (GP) and functional dyspepsia (FD) have similar symptoms, but the pathophysiology of postprandial symptoms remains uncertain.

AIMS

To compare symptoms and gastric myoelectrical activity (GMA) after liquid and solid test meals in patients with GP and FD.

METHODS

Patients enrolled in the Gastroparesis Clinical Research Consortium Registry were studied. Clinical characteristics were measured with standard questionnaires. GP was determined by 4-h solid-phase gastric scintigraphy. GMA was measured using electrogastrography before and after ingestion of a water load or nutrient bar on separate days. Symptoms were measured on visual analog scales. GMA responses to the water load for individual patients were also determined.

RESULTS

284 patients with GP and 113 with FD were identified who ingested both test meals. Patients with GP and FD had similar maximal tolerated volumes of water [mean (SD) 378 (218) ml vs. 402 (226) ml, p = 0.23] and reported similar intensity of fullness, nausea, bloating, and abdominal discomfort after the test meals. Twenty-six percent and 19% of the patients with GP and FD, respectively, ingested subthreshold (<238 ml) volumes of water (p = 0.15). Gastric dysrhythmias were recorded in 66% of the GP and 65% of the FD patients after the water load. Symptoms and GMA were similar in both groups after ingestion of the nutrient bar.

CONCLUSION

The similarity in GMA responses and symptoms after ingestion of solid or liquid test meals suggests GP and FD are closely related gastric neuromuscular disorders.

Cereset Research Standard Operating Procedures for Insomnia: A Randomized, Controlled Clinical Trial

Background

Interventions for insomnia that also address autonomic dysfunction are needed.

Objective

We evaluate Cereset Research™ Standard Operating Procedures (CR-SOP) in a pilot randomized, controlled trial. CR-SOP is a less operator-dependent, more generalizable innovation of HIRREM^®, a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology demonstrated to improve insomnia and autonomic function.

Methods

Adults with Insomnia Severity Index (ISI) scores of ≥8 were randomized to receive ten sessions of CR-SOP, with tones linked to brainwaves (LB, intervention), or a sham condition of random tones not linked to brainwaves (NL, control). Measures were collected at enrollment and 0-14 days and 4-6 weeks post-allocated intervention. The primary outcome was differential change in ISI from baseline to 4-6 weeks post-intervention. Secondary self-report measures assessed sleep quality65 and behavioral outcomes. Ten-minute recordings of heart rate and blood pressure were collected to analyze autonomic function (heart rate variability [HRV] and baroreflex sensitivity).

Results

Of 22 randomized, 20 participants completed the allocated condition. Intention to treat analysis of change from baseline to the 4-6 week outcome demonstrated mean ISI score reduction of 4.69 points among controls (SE 1.40). In the intervention group, there was an additional 2.58 point reduction in ISI score (SE 2.13; total reduction of 7.27, P = .24). Sleep quality and some measures of autonomic function improved significantly among the intervention group compared to control.

Conclusions

This pilot study compared use of a standardized, allostatic, acoustic neurotechnology intervention with a sham, active control condition. The magnitude of change in insomnia severity was clinically relevant and similar to the findings in a prior, fully powered trial, but the differential improvement observed was not statistically significant. Significant improvements were demonstrated in sleep quality and some autonomic function measures.

Psychosocial stress increases risk for type 2 diabetes in female cynomolgus macaques consuming a western diet

Chronic psychosocial stress is associated with increased risk of many chronic diseases including type 2 diabetes mellitus. However, it is difficult to establish a causal relationship between stress and diabetes in human studies because stressors often are self-reported and may be distant in time from metabolic consequences. Macaques are useful models of the effects of chronic psychosocial stress on health and may develop obesity and diabetes similar to human beings. Thus, we studied the relationships between social subordination stress - a well-validated psychological stressor in macaques - and body composition and carbohydrate metabolism in socially housed, middle-aged female cynomolgus monkeys (Macaca fascicularis; n = 42). Following an 8-week baseline phase, the monkeys were fed a Western diet for 36 months (about equivalent to 10 human years). Social status was determined based on the outcomes of agonistic interactions (X¯= 33.3 observation hours/monkey). Phenotypes collected included plasma cortisol, body composition, circulating markers of glucose metabolism, activity levels, and heart rate variability measured as RMSSD (root of mean square of successive differences) and SDDN (standard deviation of beat to beat interval) after 1.5- and 3-years on diet. Mixed model analyses of variance revealed that aggression received, submissions sent, and cortisol were higher, and RMSSD and SDNN were lower in subordinates than dominants (social status: p < 0.05). After 3 years of Western diet consumption, fasting triglyceride, glucose and insulin concentrations, calculated insulin resistance (HOMA-IR), body weight and body fat mass increased in all animals (time: all p's < 0.05); however, the increase in fasting glucose and HOMA-IR was significantly greater in subordinates than dominants (time x social status: p's < 0.05). Impaired glucose metabolism, (glucose > 100 mg/dl) incidence was significantly higher in subordinates (23%) than dominants (0%) (Fisher's exact test, p < 0.05). These findings suggest that chronic psychosocial stress, on a Western diet background, significantly increases type 2 diabetes risk in middle-aged female primates.

Children with chronic nausea and orthostatic intolerance have unique brain network organization: A case-control trial

BACKGROUND

Determine whether subjects with chronic nausea and orthostatic intolerance share common alterations in key brain networks associated with central autonomic control: default mode, salience, and central executive networks, and the insula, a key component of the salience network.

METHODS

Ten subjects (ages 12-18 years; 8 females, 2 males) with nausea predominant dyspepsia, orthostatic intolerance, and abnormal head-upright tilt test were consecutively recruited from pediatric gastroenterology clinic. These subjects were compared with healthy controls (n = 8) without GI symptoms or orthostatic intolerance. Resting-state fMRI and brain network modularity analyses were performed. Differences in the default mode, salience, and central executive networks, and insular connectivity were measured.

KEY RESULTS

The community structure of the default mode network and salience network was significantly different between tilt-abnormal children and controls (p = 0.034 and 0.012, respectively), whereas, no group difference was observed in the central executive network (p = 0.48). The default mode network was more consistently "intact," and the consistency of the community structure in the salience network was reduced in tilt-abnormal children, especially in the insula.

CONCLUSIONS AND INFERENCES

Children with chronic nausea and orthostatic intolerance have altered connectivity in the default mode network and salience network/insula, which supports over-monitoring of their body and altered processing of bodily states resulting in interoceptive hyper self-awareness. The connectivity of the salience network would not support optimal regulation of appropriate attention to internal and external stimuli, and the hyper-connected default mode network may result in a persistent self-referential state with feelings of emotion, pain, and anxiety.

Abstract P150: Sex Differences In Augmentation Index And Aortic Pulse Pressure Among Patients Diagnosed With Acute Primary Intracerebral Hemorrhage

Introduction: Intracerebral hemorrhage (ICH) is the second most common subtype of stroke. Hypertension is a major cause of primary spontaneous ICH. However, sex difference in blood pressure (BP) and arterial stiffness among ICH patients is not well characterized.

Methods: A prospective pilot study to investigate the feasibility of measuring arterial stiffness in acute primary ICH patients was approved by the institutional research board at Wake Forest Baptist Health. Eligible subjects with primary ICH were enrolled in the study within 7 days of onset. Non-invasive measurements of brachial BP, aortic BP, augmentation index at heart rate of 75 beats per minute (AIx75), and carotid-femoral pulse wave velocity (cf-PWV) were measured at the patient’s bedside, using the SphygmoCor XCEL System v1 (AtCor Medical Pty Ltd., Sydney, Australia).

Results: A total of 20 patients have been enrolled in the study over 5 months. Over half the patients enrolled were female (55%, n = 11), including 82% (n = 9) White, 9% (n = 1) Asian and 9% (n = 1) Hispanic. There was increased diversity in the male patients (45%, n = 9) including 44% (n = 4) Black, 22% (n = 2) White, 22% (n = 2) Hispanic, and 11% (n = 1) Asian. Men were significantly younger than women (57 ± 5 years vs 74 ± 3 years, respectively, P = 0.009). There were no significant differences in BMI or ICH score. At the time of measurement, there were no significant sex differences in brachial or aortic blood pressures (systolic and diastolic), however, females had significantly higher AIx75 (35 ± 4 vs 20 ± 6, P = 0.036) and aortic PP (53 ± 2 mm Hg vs 42 ± 4 mm Hg, P = 0.020) than males. Sex difference in cf-PWV was not statistically significant (p = 0.054).

Conclusion: In the current feasibility pilot study, preliminary data show that females had higher arterial stiffness measured as AIx75 and aortic PP than males in the acute setting of ICH. Further study will be required to ascertain whether this is related to higher age at presentation in females. Whether sex differences in arterial stiffness predict differences in the outcome among ICH patients is not well characterized; thus, assessment of 30-day functional and neurological outcomes will be performed with NIHSS and modified Rankin Scores.

Abstract P206: Improvement Of Autonomic Function, Sleep, Depression, Anxiety, And Stress In Military Personnel With Traumatic Stress After Use Of A Closed Loop Neurotechnology

Introduction: Symptoms associated with military-related traumatic stress (MTS) include insomnia, depression, anxiety, and impaired autonomic control. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop acoustic stimulation technology that identifies dominant brain frequencies and translates them in real time into audible tones of variable pitch and timing, to support self-optimization of brain activity.

Objective: Evaluate changes in autonomic and symptoms scores after use of HIRREM in subjects enrolled in a pilot study for MTS.

Methods: Thirty-two service members or Veterans (1 female), mean (SD) age 40.8 (6.4), with MTS symptoms for 7.3 years (3.9), received 19.2 (1.0) HIRREM sessions over 12 days. Continuous recordings of blood pressure and heart rate, for analysis of baroreflex sensitivity (BRS) and heart rate variability (HRV), were done at V1 and V2. Symptom inventories collected before (Visit 1, V1), immediately after (primary outcome, V2, n = 32), and at 1, 3, and 6 months after completion of HIRREM included traumatic stress (PCL-M), insomnia (ISI), depression (CES-D), and anxiety (GAD-7). Paired t-tests were performed.

Results: HIRREM improved BRS measured as HF alpha (10.8 ms/mmHg, 2.5, p<0.001), Sequence Down (7.3 ms/mmHg, 2.1, p<0.001), Sequence Up (7.6 ms/mmHg, 2.4, p=0.001), and Sequence All (7.3 ms/mmHg, 1.8, p<0.001), as well as HRV; SDNN (14.1 ms, 3.6, p=0.005), rMSSD (12.8 ms, 2.6, p<0.05). MAP dropped 2.7 mmHg, 1.2, p<0.05 and SAP dropped 5.9 mmHg, 1.8, p=0.007. Mean symptom scores were reduced at V2; PCL-M [-12.9 (± 9.1), p<0.001], ISI [-6.3 (± 5.0), p<0.001], CES-D [-13.7 (±9.2), p<0.001], and GAD-7 [-6.7. (± 4.7), p<0.001]. Symptom scores improved 1-month post-HIRREM for all measures, and clinically relevant and significant benefits persist at 3 and 6 months.

Conclusions: These results suggest improved autonomic cardiovascular regulation and statistically significant reduction in scales associated with the use of HIRREM for symptoms of MTS. Controlled trials could provide important insights regarding both the mechanisms associated with the beneficial effects of HIRREM, and the functional disturbances underlying MTS.

Abstract P223: Vitamin D Supplementation Improves Measures Of Arterial Stiffness And Vascular Function In Adolescents Suffering From Orthostatic Intolerance

Background: In previous work we identified a group of adolescents with orthostatic intolerance (OI) presenting as postural orthostatic tachycardia syndrome or syncope with impairment in autonomic and vascular response upon head up tilt. Low vitamin D level correlated with the severity of symptoms. In this pilot study we hypothesized that vitamin D supplementation will improve the vascular function in these adolescents.

Methods: A cohort of twenty Adolescents (mean age= 16.2 years, 4 males) who are vitamin D deficient had a non-invasive measurements of brachial BP, aortic BP, augmentation index at heart rate of 75 beats per minute (AIx75), and carotid-femoral pulse wave velocity (cf-PWV) using the SphygmoCor XCEL System at baseline and after two months of vitamin D supplementation (2000-5000 IU daily based on baseline level). Both right and left side ankle pressure and ankle brachial index (ABI) were assessed using COLIN VP-1000 vascular profiling system. Impedance Cardiography (ICG) was used to estimate total arterial compliance (TAC) and thoracic fluid content (TFC) in supine position at rest and after hand grip challenge.

Results: As shown in the table. Compared to baseline, vitamin D supplementation increased vitamin D level, increased TAC and TFC at baseline and under stress challenge. It also tended to reduced AIx75 and cf-PWV and reduced both right and left ankle pressure and ABI

Conclusions: Vitamin D supplementation improved different measures of vascular function in adolescent. These data provides evidence of potential therapeutic benefit of vitamin D supplementation for patients suffering from orthostatic intolerance who are vitamin D deficient.

Abstract P205: Use Of A Noninvasive, Closed-loop, Allostatic, Neurotechnology Reduced Blood Pressure And Improved Sleep In Heterogeneous Cohort

Introduction: Elevated blood pressure is a major modifiable risk for cardiovascular disease. Disturbed central control of cardiovascular regulation due to trauma, stress, anxiety or other causes can lead to rise in blood pressure. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology using software algorithms to identify specific brain frequencies, and translate them in real time into audible tones, to support self-optimization of brain rhythms.

Objective: To evaluate the benefits of adding this nontraditional therapy on BP and symptoms of insomnia in subjects with normal or controlled BP, who are enrolled in an IRB-approved open label feasibility study evaluating HIRREM for diverse neuropsychological disorders.

Methods: 236 participants (105 female), mean (SD) age 43.1 (16.5), received 15.7 (4.8) HIRREM sessions over 22.6 (18.2) days, (9.3 (3.4) days with sessions). Brachial BP and insomnia score (ISI) were collected before, and 14.0 (14.0) days after HIRREM completion. Paired t-tests were performed.

Results: Before HIRREM, participants were divided in the following groups based on ACC/AHA 2017 BP guidelines, normal n=78, elevated n=36, stage 1 n=50, stage 2 n=57, stage 3 n=14 and crisis n=2. There were no changes in medications throughout the study duration. The use of HIRREM was associated with significant reduction in systolic BP (from 126.1 (19.0) to 123.5 (17.0) mmHg, p=0.007), and diastolic BP (from 75.3 (10.6) to 73.0 (9.0) mmHg, p<0.001), with no change in heart rate. Many participants moved to lower BP stage after V2 with the number of participants within normal BP at V2 increasing from 78 to 88. ISI score decreased from 13.2 (7.2) to 6.7 (5.6), p<0.0001. This change met the clinically meaningful drop in ISI of 6 points or more.

Conclusion: These data provide evidence of significant benefits of adding a closed-loop therapy for blood pressure reduction and improving sleep. Further studies are indicated to better define the role of this promising intervention to improve sleep, depression, anxiety, and cardiovascular outcomes.

Sex Differences in MicroRNA Expression and Cardiometabolic Risk Factors in Hispanic Adolescents with Obesity

OBJECTIVE

To evaluate sex differences in microRNA (miRNA) expression, anthropometric measures, and cardiometabolic risk factors in Hispanic adolescents with obesity.

STUDY DESIGN

Cross-sectional study of 68 (60% male) Hispanic adolescents with obesity, aged 13-17 years, recruited from a pediatric weight management clinic. We used small RNA sequencing to identify differentially expressed circulating miRNAs. We used ingenuity pathway analysis and David bioinformatic resource tools to identify target genes for these miRNAs and enriched pathways. We used standard procedures to measure anthropometric and cardiometabolic factors.

RESULTS

We identified 5 miRNAs (miR-24-3p, miR-361-3p, miR-3605-5p, miR-486-5p, and miR-199b-3p) that differed between females and males. miRNA targets-enriched pathways included phosphatidylinositol 3-kinase-protein, 5' AMP-activated protein kinase, insulin resistance, sphingolipid, transforming growth factor-β, adipocyte lipolysis regulation, and oxytocin signaling pathways. In addition, there were sex differences in blood pressure, skeletal muscle mass, lean body mass, and percent body fat.

CONCLUSIONS

We have identified sex differences in miRNA expression in Hispanic adolescents relevant to cardiometabolic health. Future studies should focus on sex-specific mechanistic roles of miRNAs on gene pathways associated with obesity pathophysiology to support development of precision cardiometabolic interventions.

Renin-angiotensin system blockade in the COVID-19 pandemic

In the early months of the coronavirus disease 2019 (COVID-19) pandemic, a hypothesis emerged suggesting that pharmacologic inhibitors of the renin–angiotensin system (RAS) may increase COVID-19 severity. This hypothesis was based on the role of angiotensin-converting enzyme 2 (ACE2), a counterregulatory component of the RAS, as the binding site for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), allowing viral entry into host cells. Extrapolations from prior evidence led to speculation that upregulation of ACE2 by RAS blockade may increase the risk of adverse outcomes from COVID-19. However, counterarguments pointed to evidence of potential protective effects of ACE2 and RAS blockade with regard to acute lung injury, as well as substantial risks from discontinuing these commonly used and important medications. Here we provide an overview of classic RAS physiology and the crucial role of ACE2 in systemic pathways affected by COVID-19. Additionally, we critically review the physiologic and epidemiologic evidence surrounding the interactions between RAS blockade and COVID-19. We review recently published trial evidence and propose important future directions to improve upon our understanding of these relationships.

High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM) improves symptoms and autonomic function for insomnia: A randomized, placebo-controlled clinical trial

INTRODUCTION

Effective insomnia interventions that also address autonomic dysregulation are lacking. We evaluate high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM® ), in a randomized, controlled clinical trial. HIRREM is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology, to support self-optimization of brain rhythms.

METHODS

One hundred and seven adults (mean age 45.7, SD ± 5.6, 73 women), with Insomnia Severity Index (ISI) scores of ≥15, received ten, 90-min sessions of HIRREM, with tones linked to brainwaves (LB, 56), or random tones not linked to brainwaves (NL, 51), as an active, sham placebo. Outcomes were obtained at enrollment (V1), 1-7 days (V2), 8-10 weeks (V3), and 16-18 weeks (V4) after intervention. Primary outcome was differential change in ISI from V1 to V3. Secondary measures assessed depression (BDI), anxiety (BAI), quality of life (EQ-5D), and a sleep diary. Ten minute recordings of HR and BP allowed analysis of heart rate variability (HRV) and baroreflex sensitivity (BRS).

RESULTS

Of 107 randomized, 101 completed the intervention. Intention-to-treat analysis (107) of change from V1 to V3 revealed a mean reduction of ISI in NL of -4.93 (SE ± 0.76) points, with additional, significant reduction of -2.05 points (0.74) in LB (total reduction of -6.98, p = .045). Additional reduction of -2.30 points (0.76) was still present in the LB at V4 (p = .058). Total ISI reduction from V1 to V4 was -5.90 points for NL and -7.93 points in LB. There were group differences (p < .05) for multiple HRV and BRS measures (rMSSD, SDNN, HF alpha, and Seq ALL), as well as total sleep time, sleep onset latency, and sleep efficiency. There were no serious adverse events.

CONCLUSIONS

Results of this controlled clinical trial showed clinically relevant reduction of insomnia symptoms with HIRREM, over, and above an active, sham control, with associated, durable improvement in autonomic cardiovascular regulation.

Mediterranean diet, stress resilience, and aging in nonhuman primates

Persistent psychological stress increases the risk of many chronic diseases of aging. Little progress has been made to effectively reduce stress responses or mitigate stress effects suggesting a need for better understanding of factors that influence stress responses. Limited evidence suggests that diet may be a factor in modifying the effects of stress. However, long-term studies of diet effects on stress reactive systems are not available, and controlled randomized clinical trials are difficult and costly. Here we report the outcomes of a controlled, randomized preclinical trial of the effects of long-term consumption (31 months, ~ equivalent to 9 human years) of Western versus Mediterranean - like diets on behavioral and physiological responses to acute (brief social separation) and chronic (social subordination) psychosocial stress in 38 adult, socially-housed, female cynomolgus macaques. Compared to animals fed a Western diet, those fed the Mediterranean diet exhibited enhanced stress resilience as indicated by lower sympathetic activity, brisker and more overt heart rate responses to acute stress, more rapid recovery, and lower cortisol responses to acute psychological stress and adrenocorticotropin (ACTH) challenge. Furthermore, age-related increases in sympathetic activity and cortisol responses to stress were delayed by the Mediterranean diet. Population level diet modification in humans has been shown to be feasible. Our findings suggest that population-wide adoption of a Mediterranean-like diet pattern may provide a cost-effective intervention on psychological stress and promote healthy aging with the potential for widespread efficacy.

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There is no population level treatment to reduce stress and associated disease.

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Mediterranean diet reduced sympathetic activity.

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Mediterranean diet reduced cortisol response to acute stress and to ACTH challenge.

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Mediterranean diet delayed age-related increases in sympathetic activity and cortisol responses to stress.

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These results suggest a dietary strategy to increase stress resilience.

Abstract P198: Vitamin D Supplementation Improves Autonomic Response To Head Up Tilt In Adolescents Suffering From Orthostatic Intolerance

Background: We have previously shown in a group of adolescents who are suffering from orthostatic intolerance (OI) and syncope that they exhibited impairment in autonomic function in supine position and greater loss of baroreflex sensitivity (BRS) and heart rate variability (HRV) measures upon head up tilt (HUT). They also had low vitamin D level that correlated with the severity of symptoms on tilt. In this pilot study we hypothesized that vitamin D supplementation to normal levels will improve the autonomic response to change in position.

Methods: In a pilot group of eight female adolescents (mean age= 16.0 years) who are vitamin D deficient, head up tilt was done at baseline and after two months of vitamin D supplementation (2000-5000 IU daily based on baseline level). Heart rate, blood pressure, BRS measured as Sequence Up (parasympathetic) and Sequence down (sympathetic), HRV measured as SDNN and rMSSD, and sympathovagal balance (LF/HF ratio) were assessed both in supine and HUT positions.

Results: As shown in the table, compared to baseline, vitamin D supplementation improved vitamin D level, minutes standing on tilt, BRS, HRV and sympathovagal balance measures at baseline and reduced the loss in BRS and HRV measures upon standing. There were no changes in blood pressure measures between pre and post treatment.

Conclusions: Vitamin D supplementation for two months restored vitamin D to normal levels and was associated with improvement in the hemodynamic response to standing. These data provide evidence of potential therapeutic benefit of vitamin D supplementation for patients suffering from orthostatic intolerance who are vitamin D deficient,

Lower urinary α-Klotho is associated with lower angiotensin-(1-7) and higher blood pressure in young adults born preterm with very low birthweight

Early-life factors including preterm birth and VLBW increase the risk of hypertension, but the mechanisms remain poorly understood. Reductions in the anti-aging protein α-klotho are associated with hypertension, possibly due to angiotensin (Ang) II activation, but the mechanisms are incompletely understood and clinical evidence is lacking. The association of α-klotho with the alternative Ang-(1-7) pathway, which counteracts Ang II to lower BP, is undescribed. We hypothesized that lower urinary α-klotho is associated with higher BP and lower urinary Ang-(1-7) in preterm-born VLBW young adults. In a cross-sectional analysis of data from a prospective cohort of 141 preterm-born VLBW young adults, we assessed the associations among urinary α-klotho/creatinine, Ang II/creatinine, Ang-(1-7)/creatinine, Ang II/Ang-(1-7), and BP using generalized linear models adjusted for age and hypertensive pregnancy and conducted a sensitivity analysis in 32 term-born young adults. Among those born preterm, lower α-klotho/creatinine was associated with higher systolic BP (adjusted β (aβ): -2.58 mm Hg, 95% CI -4.99 to -0.17), lower Ang-(1-7)/creatinine (ln aβ: 0.1, 0.04-0.16), and higher Ang II/Ang-(1-7) (ln aβ: -0.14, -0.21 to -0.07). In term-born participants, α-klotho/creatinine was inversely associated with Ang II/creatinine (ln aβ: -0.15, -0.27 to -0.03) and Ang II/Ang-(1-7) (ln aβ: -0.15, -0.27 to -0.03). In preterm-born young adults with VLBW, lower urinary α-klotho/creatinine was associated with higher SBP, lower urinary Ang-(1-7)/creatinine, and higher urinary Ang II/Ang-(1-7). Reduced renal α-klotho expression could lead to renal Ang-(1-7) suppression as a novel mechanism for the development of hypertension among individuals born preterm with VLBW.

0541 Exploratory Study of Closed-Loop, Artificial Intelligence Driven Neurotechnology Improves Self-Reported Symptoms of Insomnia, Stress, and Anxiety in First Responders

Introduction

First responders (FR) have decreased life expectancy, attributed to work-related exposure to traumatic stress and circadian disruption. In prior studies, High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) reduced symptoms and improved heart rate variability (HRV) in law enforcement personnel. HIRREM is operator dependent, difficult to scale, and many medications were excluded for prior studies. Cereset Research™ (CR) uses HIRREM core technology, echoing tones linked to brainwaves, with updated components, artificial intelligence (AI) driven protocols, and software management of designs to improve scalability. We report symptom changes in a series of first responders enrolled in an exploratory study evaluating CR for self-reported symptoms of insomnia, stress, or anxiety, including subjects taking previously excluded medications.

Methods

11 adults (4 females) meeting criteria for insomnia (ISI, of ≥8 points for ≥1 month), stress (PSS of ≥14), or anxiety (GAD-7 of ≥5), who are also FR, enrolled in this ongoing exploratory trial. Subjects receive six to twelve 60 minute sessions of CR, plus continued current care. Data collection is at baseline (V1), 0-21 days post-intervention (V2), 4-7 weeks later (V3), and 4-7 weeks thereafter (V4). Primary outcome is change in autonomic cardiovascular regulation at V3, with change in ISI, PSS, GAD-7, CES-D, and PCL-C as secondary outcomes. We report interim results for symptom outcomes at V3. HRV and baroreflex sensitivity results are pending.

Results

2 dropped out during follow-up. For n=9, median change from V1 to V3 ISI score: -6; PSS score: -4; GAD-7: -4; CES-D: -3; and PCL-C: -8. The cohort moved to no anxiety and low stress categories from V1 to V3.

Conclusion

Results suggest relevant symptom reductions among FR following use of CR, as seen previously with HIRREM for law enforcement, even with additional medications. This informs future randomized clinical trials using this scalable, non-drug intervention. Updated results will be presented.

Support: Support

Research grant received from, The Susanne Marcus Collins Foundation, Inc.

0542 Exploratory Use of Artificial Intelligence Driven Acoustic Neuromodulation Improved Sleep, Depression, Anxiety, and Stress in Adults with Persisting Post-Concussion Symptoms

Introduction

In prior studies, High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) reduced persisting post-concussion symptoms (PPCS) of insomnia and depression and improved heart rate variability (HRV), but is operator dependent, with difficulty scaling. Cereset Research™ (CR), a noninvasive, closed-loop, artificial intelligence (AI) driven, acoustic neuromodulation technology uses the same core technology, echoing tones linked to brainwaves, but includes updated components, standardized AI driven protocols, software management of designs, and shorter sessions to improve scalability. This open label trial explores use of CR for PPCS.

Methods

5 adults (1 female, median age = 48, 31-64) with PPCS received a median of 8 CR sessions (range 7-9, 60 minutes each) over 11 (5-18) days as part of an open label IRB-approved exploratory study of CR for diverse health conditions. Data is collected at baseline (V1), 0-21 days (V2), 4-7 weeks later (V3), and 4-7 weeks thereafter (V4). Pre- and post-CR symptom inventories included concussion (RPQ), insomnia (ISI), depression (CES-D), anxiety (GAD-7), PTSD (PCL-C), and stress (PSS). Primary outcome is change in autonomics at V3 via HRV (SDNN and rMSSD) based on 10-minute BP and HR recordings using a BIOPAC device. Formal analysis of HRV outcome is pending, but we report preliminary changes in symptom outcomes.

Results

6 subjects have enrolled for sleep trouble related to PCCS, with 1 lost to follow-up after receiving intervention. For V1-V2 (n=5), median change in RPQ score is -23, ISI -10, CES-D -16, GAD-7 -7, PCL-C -16, and PSS -7. For V1-V3 (n=4), median change in RPQ -19, ISI -10.5, CES-D -6, GAD-7 -4.5, PCL-C -14.5, and PSS -3. No serious adverse events reported.

Conclusion

Preliminary results suggest similar, clinically meaningful reductions in ISI score, and concussion symptoms, as seen with HIRREM, suggesting promise as a scalable, non-drug intervention for insomnia with PPCS. Updated results will be presented.

Support: Support

Research grant received from, The Susanne Marcus Collins Foundation, Inc.

Pilot Trial of a Noninvasive Closed-Loop Neurotechnology for Stress-Related Symptoms in Law Enforcement: Improvements in Self-Reported Symptoms and Autonomic Function

Background

Law enforcement officers have decreased life expectancy, attributed to work-related exposure to traumatic stress and circadian disruption. Autonomic dysregulation is reported with traumatic stress and chronic insomnia.

Objective

We explore potential benefits for reduced symptoms related to stress and insomnia and improved autonomic function associated with open label use of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®), in a cohort of sworn law enforcement personnel.

Methods

Closed-loop noninvasive therapies utilizing real-time monitoring offer a patient-centric approach for brain-based intervention. HIRREM® is a noninvasive, closed-loop, allostatic, neurotechnology that echoes specific brain frequencies in real time as audible tones to support self-optimization of brain rhythms. Self-report symptom inventories done before and after HIRREM included insomnia (ISI), depression (CES-D), traumatic stress (PCL-C), anxiety (GAD-7), perceived stress (PSS), and quality of life (EQ-5D). Ten-minute recordings of heart rate and blood pressure allowed analysis of baroreflex sensitivity (BRS) and heart rate variability (HRV).

Results

Fifteen participants (1 female), mean (SD) age 45.7 (5.6), received 12.2 (2.7) HIRREM sessions, over 7.9 in-office days. Data were collected at baseline, and at 22.8 (9.2), and 67.2 (14.1) days after intervention. All symptom inventories improved significantly (P < .01), with durability for 2 months after completion of the intervention. The use of HIRREM was also associated with significant increases (P < .001) in HRV measured as rMSSD and BRS measured by high-frequency alpha index. There were no serious adverse events or drop outs.

Conclusion

These pilot data provide the first report of significant symptom reductions, and associated improvement in measures of autonomic cardiovascular regulation, with the use of HIRREM in a cohort of law enforcement personnel. Randomized clinical trials are warranted.

Association of circulating uric acid and angiotensin-(1-7) in relation to higher blood pressure in adolescents and the influence of preterm birth

Elevated serum uric acid increases the risk of hypertension, and individuals born preterm have higher blood pressure (BP) and uric acid, but the mechanisms remain unclear. Preclinical studies demonstrate uric acid increases BP via increased renin-angiotensin system (RAS) expression, especially angiotensin (Ang) II, but the association of uric acid with Ang-(1–7) is unknown. Ang-(1–7), an alternative RAS product, counteracts Ang II by stimulating sodium excretion, vasodilation, and nitric oxide, thus contributing to lower BP. Plasma Ang-(1–7) is lower in preterm-born adolescents. We hypothesized uric acid is associated with a higher ratio of Ang II to Ang-(1–7) in plasma, especially in preterm-born adolescents. We measured BP, serum uric acid, and plasma RAS components in a cross-sectional analysis of 163 14-year-olds (120 preterm, 43 term). We estimated the associations between uric acid and the RAS using generalized linear models adjusted for sex, obesity, sodium intake, and fat intake, stratified by birth status. Uric acid was positively associated with Ang II/Ang-(1–7) (adjusted β (aβ): 0.88 mg/dl, 95% CI 0.17 to 1.58), plasma renin activity (aβ: 0.32 mg/dl, 95% CI 0.07 to 0.56), and aldosterone (aβ: 1.26 mg/dl, 95% CI 0.18 to 2.35), and inversely with Ang-(1–7) (aβ: −1.11 mg/dl, 95% CI −2.39 to 0.18); preterm birth did not modify these associations. Higher Ang II/Ang-(1–7) was associated with higher uric acid in adolescents. As preterm birth is associated with higher BP and uric acid, but lower Ang-(1–7), the imbalance between uric acid and Ang-(1–7) may be an important mechanism for the development of hypertension.

Association of Heart Rate Variability With Cognitive Performance: The Multi-Ethnic Study of Atherosclerosis

Background Heart rate variability (HRV) is associated with vascular risk factors for dementia, but whether HRV is associated with specific domains of cognitive performance is unclear. Methods and Results In the Multi-Ethnic Study of Atherosclerosis (N=3018; mean age 59.3±9.2 years), we assessed the relationship of 10-second HRV to scores on tests of global cognitive performance (Cognitive Abilities Screening Instrument), processing speed (Digit Symbol Coding), and working memory (Digit Span). HRV was computed as the SD of normal-normal intervals (SDNN) and root mean square of successive differences (RMSSD) at Exam 1 (2000-2002) and Exam 5 (2010-2012). Cognitive tests were administered at Exam 5. We report regression coefficients (β [95% CI]) representing cognitive test score change per 2-fold increase in HRV. After adjustment for age, race/ethnicity, sex, education, apolipoprotein E genotype, and cardiovascular risk factors and incident disease, higher Exam 1 (β=0.37 [0.06, 0.67]) and Exam 5 (β=0.31 [0.04, 0.59]) SDNN were associated with better Cognitive Abilities Screening Instrument performance. Higher Exam 1 (β=0.80 [0.17, 1.43]) and Exam 5 (β=0.63 [0.06, 1.20]) SDNN, and Exam 5 RMSSD (β=0.54 [0.01, 1.08]) were associated with better Digit Symbol Coding performance. Finally, higher Exam 5 SDNN was associated with better Digit Span performance (β=0.17 [0.01, 0.33]). Associations were attenuated after adjustment for resting heart rate. Conclusions Higher HRV is generally associated with better cognitive performance in this multi-ethnic cohort of aging adults, and further study of the relationship of autonomic function to cognition is warranted.

Antenatal Steroid Exposure, Aerobic Fitness, and Physical Activity in Adolescents Born Preterm with Very Low Birth Weight

OBJECTIVE

To determine whether antenatal corticosteroid exposure is associated with aerobic fitness or physical activity participation in adolescents born preterm with very low birth weight (VLBW).

STUDY DESIGN

Observational cohort study of 14-year-old adolescents (n = 173) born with VLBW between 1992 and 1996 at a regional perinatal center with 91 exposed to antenatal corticosteroids. Aerobic fitness was determined from peak oxygen uptake (V˙O2peak) obtained via maximal exercise testing on a cycle ergometer. Physical activity levels for the past year and past 2 months were estimated from a questionnaire. Between-group comparisons for continuous variables were evaluated using independent t tests or Mann-Whitney U tests. Generalized linear models were used to compare differences in fitness and physical activity between those exposed to antenatal corticosteroids and not exposed to antenatal corticosteroids, with race and sex in models.

RESULTS

Regression analysis revealed an antenatal corticosteroids × sex × race interaction for V˙O2peak (P ≤ .001). Nonblack male adolescents exposed to antenatal corticosteroids had significantly greater V˙O2peak than nonblack male adolescents not exposed to antenatal corticosteroids expressed relative to body mass (mean difference [95% CI]; 8.5 [2.1-15.0] mL·kg-1·min-1) and lean body mass (9.0 [1.1-16.9] mL·kglean body mass-1·min-1). No antenatal corticosteroid group differences in V˙O2peak were evident in black male adolescents, or black and nonblack female adolescents. Male adolescents exposed to antenatal corticosteroids reported participating in significantly more total physical activity (medians: 14.6 vs 8.5) and vigorous physical activity (3.0 vs 0.95) per week for the past 2 months than male adolescents not exposed to antenatal corticosteroids.

CONCLUSIONS

Exposure to antenatal corticosteroids was associated with greater physical activity participation and aerobic fitness in adolescents with VLBW, particularly in nonblack male adolescents, which may confer health benefits in this at-risk population.

Abstract P2062: Vitamin D Supplementation Improves Vascular Function in Adolescents Suffering from Orthostatic Intolerance

Background: In previous work we identified a group of adolescents whose diagnostic workup for chronic unexplained nausea revealed underlying cardiovascular instability manifesting as orthostatic intolerance (OI) and syncope. These patients exhibited impairment in autonomic and vascular function and excessive release of catecholamines upon head up tilt compared to pre tilt. They also had low vitamin D level that correlated with the severity of symptoms on tilt. In this pilot study we hypothesized that vitamin D supplementation to normal levels will improve the vascular function in these participants.

Methods: A cohort of ten Adolescents (mean age= 16.3 years) who are vitamin D deficient had a head up tilt at baseline and after two months of vitamin D supplementation (2000-5000 IU daily based on baseline level). Heart rate, blood pressure, cardiac work index, arterial compliance and pulse wave velocity (PWV) were measured in supine position.

Results: As shown in the table. Compared to baseline, vitamin D supplementation improved vitamin D level, arterial compliance and reduced cardiac work index under stress challenge and baseline PWV.

Conclusions: Vitamin D supplementation for two months restored vitamin D to normal levels and was associated with improvement in the vascular function. These data provides evidence of potential therapeutic benefit of vitamin D supplementation for patients suffering from orthostatic intolerance and syncope who are vitamin D deficient.

The Role of Heart Rate Variability in Mindfulness-Based Pain Relief

Mindfulness meditation is a self-regulatory practice premised on sustaining nonreactive awareness of arising sensory events that reliably reduces pain. Yet, the specific analgesic mechanisms supporting mindfulness have not been comprehensively disentangled from the potential nonspecific factors supporting this technique. Increased parasympathetic nervous system (PNS) activity is associated with pain relief corresponding to a number of cognitive manipulations. However, the relationship between the PNS and mindfulness-based pain attenuation remains unknown. The primary objective of the present study was to determine the role of high-frequency heart rate variability (HF HRV), a marker of PNS activity, during mindfulness-based pain relief as compared to a validated, sham-mindfulness meditation technique that served as a breathing-based control. Sixty-two healthy volunteers (31 females; 31 males) were randomized to a 4-session (25 min/session) mindfulness or sham-mindfulness training regimen. Before and after each group's respective training, participants were administered noxious (49°C) and innocuous (35°C) heat to the right calf. HF HRV and respiration rate were recorded during thermal stimulation and pain intensity and unpleasantness ratings were collected after each stimulation series. The primary analysis revealed that during mindfulness meditation, higher HF HRV was more strongly associated with lower pain unpleasantness ratings when compared to sham-mindfulness meditation (B = -.82, P = .04). This finding is in line with the prediction that mindfulness-based meditation engages distinct mechanisms from sham-mindfulness meditation to reduce pain. However, the same prediction was not confirmed for pain intensity ratings (B = -.41). Secondary analyses determined that mindfulness and sham-mindfulness meditation similarly reduced pain ratings, decreased respiration rate, and increased HF HRV (between group ps < .05). More mechanistic work is needed to reliably determine the role of parasympathetic activation in mindfulness-based pain relief as compared to other meditative techniques. Perspective: Mindfulness has been shown to engage multiple mechanisms to reduce pain. The present study extends on this work to show that higher HRV is associated with mindfulness-induced reductions in pain unpleasantness, but not pain intensity ratings, when compared to sham-mindfulness meditation. These findings warrant further investigation into the mechanisms engaged by mindfulness as compared to placebo.

Children with orthostatic intolerance exhibit elevated markers of inflammation in the dorsal medulla

Children with orthostatic intolerance (OI) have exaggerated decreases in heart rate variability (HRV) and suppression of baroreflex sensitivity (BRS) with standing. Accompanying brain transmitter and metabolite profiles are unknown. In this study, we used proton (¹H) magnetic resonance spectroscopy (¹H-MRS) to quantify markers of neuronal and glial integrity in a pilot study of children with OI compared with asymptomatic controls. Eighteen participants ages 10-18 yr were evaluated for blood pressure, heart rate (HR), and calculated indexes of autonomic function in supine and upright positions and, within an average of 2 wk, underwent ¹H-MRS scans of dorsal medulla on a clinical 3T magnet while supine. As a result, of the 18 participants, 11 tested positive for OI and 7 did not. OI subjects exhibited higher HR and lower HRV and high-frequency α-index (HFα), an index of parasympathetic vagal tone, during standing compared with non-OI. HRV, sequence all (Seq All), high- and low-frequency (HFα and LFα) estimates of the spontaneous BRS decreased significantly, while BP variabilty increased significantly during standing only in subjects with OI. OI subjects had higher myoinositol (mIns) and total choline (tCho), markers of glial inflammation. Upright HFα and Seq All inversely correlated to supine tCho and mIns, respectively, independent of age and sex. In conclusions, in this pilot study, children with OI exhibit higher mIns and tCho in the dorsal medulla while supine that may reflect the well-established impairment in regulation of the autonomic nervous system upon standing. Neuroinflammation as an underlying cause or consequence of autonomic dysfunction is an intriguing possibility requiring further study.NEW & NOTEWORTHY (¹H) magnetic resonance spectroscopy detected elevated markers of neuroinflammation in the dorsal medulla in children with impaired autonomic responses to head upright tilt. This first report of altered brain metabolites in this population provides a basis for future clinical studies using this methodology to aide in understanding complex autonomic disease states.

Central ANG-(1-7) infusion improves blood pressure regulation in antenatal betamethasone-exposed sheep and reveals sex-dependent effects on oxidative stress

Fetal exposure to betamethasone (BMX) as a consequence of glucocorticoid administration to women threatening premature delivery may lead to long-term deleterious effects on the cardiovascular system and dysregulation of blood pressure in exposed adults. Indeed, adult offspring of BMX sheep exhibit increased mean arterial pressure (MAP) and attenuated baroreflex sensitivity (BRS) that are associated with lower medullary and cerebrospinal fluid (CSF) angiotensin-(1-7) [(ANG-(1-7)] content. Thus we determined the effects of ANG-(1-7) supplementation in the CSF on MAP, BRS, blood pressure (BPV) and heart rate variability (HRV) in conscious animals. The peptide or artificial CSF (aCSF) was infused continuously into the lateral ventricle (intracerebroventricular) of 4-mo-old male and female BMX sheep for 2 wk. Analysis of data from males and females combined revealed that intracerebroventricular ANG-(1-7) significantly lowered MAP and heart rate and improved BRS as compared with baseline; intracerebroventricular aCSF did not change these indexes. Similar patterns were observed for altered hemodynamics and autonomic function produced by intracerebroventricular ANG-(1-7) in both sexes. Oxidative stress and MAP kinase (MAPK) activation were lower in tissues from the dorsomedial medulla (DMM) of ANG-(1-7)-treated males but were unchanged in the treated females, when assessed at the end of the treatment period. We conclude that in the face of ANG-(1-7) deficiency in CSF and medullary tissue in BMX sheep intracerebroventricular supplementation of ANG-(1-7) lowers MAP and restores the impaired autonomic function to a similar degree in both males and females; however, the attenuation of MAPK and oxidative stress within the DMM was evident only in males. NEW & NOTEWORTHY We demonstrate that intracerebroventricular angiotensin-(1-7) [(ANG-(1-7)] treatment for 2 wk in antenatal betamethasone-exposed sheep provides beneficial effects on blood pressure and autonomic function. The physiological improvements are accompanied by an attenuation of oxidative stress in males but not females. The finding that ANG-(1-7) supplementation lowers blood pressure and restores the impaired autonomic function in a model of fetal programming previously shown to exhibit a deficiency in cerebrospinal fluid and brain tissue illustrates the potential for new therapeutic strategies for reducing cardiovascular dysfunction arising from prenatal events.

Obesity is Associated with Higher Blood Pressure and Higher Levels of Angiotensin II but Lower Angiotensin-(1-7) in Adolescents Born Preterm

OBJECTIVES

To evaluate if obesity is associated with increased angiotensin II (Ang II) and decreased angiotensin-(1-7) or Ang-(1-7) in the circulation and urine among adolescents born prematurely.

STUDY DESIGN

In a cross-sectional analysis of 175 14-year-olds born preterm with very low birth weight, we quantified plasma and urinary Ang II and Ang-(1-7) and compared their levels between subjects with overweight/obesity (body mass index ≥85th percentile, n = 61) and those with body mass index <85th percentile (n = 114) using generalized linear models, adjusted for race and antenatal corticosteroid exposure.

RESULTS

Overweight/obesity was associated with higher systolic blood pressure and a greater proportion with high blood pressure. After adjustment for confounders, overweight/obesity was associated with an elevated ratio of plasma Ang II to Ang-(1-7) (β: 0.57, 95% CI 0.23-0.91) and higher Ang II (β: 0.21 pmol/L, 95% CI 0.03-0.39) but lower Ang-(1-7) (β: -0.37 pmol/L, 95% CI -0.7 to -0.04). Overweight/obesity was associated with a higher ratio of urinary Ang II to Ang-(1-7) (β: 0.21, 95% CI -0.02 to 0.44), an effect that approached statistical significance.

CONCLUSIONS

Among preterm-born adolescents, overweight/obesity was associated with increased Ang II but reduced Ang-(1-7) in the circulation and the kidney as well as higher blood pressure. Obesity may compound the increased risk of hypertension and cardiovascular disease in individuals born prematurely by further augmenting the prematurity-associated imbalance in the renin-angiotensin system.

Fetal programming and the angiotensin-(1-7) axis: a review of the experimental and clinical data

Hypertension is the primary risk factor for cardiovascular disease that constitutes a serious worldwide health concern and a significant healthcare burden. As the majority of hypertension has an unknown etiology, considerable research efforts in both experimental models and human cohorts has focused on the premise that alterations in the fetal and perinatal environment are key factors in the development of hypertension in children and adults. The exact mechanisms of how fetal programming events increase the risk of hypertension and cardiovascular disease are not fully elaborated; however, the focus on alterations in the biochemical components and functional aspects of the renin-angiotensin (Ang) system (RAS) has predominated, particularly activation of the Ang-converting enzyme (ACE)-Ang II-Ang type 1 receptor (AT1R) axis. The emerging view of alternative pathways within the RAS that may functionally antagonize the Ang II axis raise the possibility that programming events also target the non-classical components of the RAS as an additional mechanism contributing to the development and progression of hypertension. In the current review, we evaluate the potential role of the ACE2-Ang-(1-7)-Mas receptor (MasR) axis of the RAS in fetal programming events and cardiovascular and renal dysfunction. Specifically, the review examines the impact of fetal programming on the Ang-(1-7) axis within the circulation, kidney, and brain such that the loss of Ang-(1-7) expression or tone, contributes to the chronic dysregulation of blood pressure (BP) and cardiometabolic disease in the offspring, as well as the influence of sex on potential programming of this pathway.

Renal function and blood pressure are altered in adolescents born preterm

BACKGROUND

Preterm birth increases the risk of hypertension and kidney disease. However, it is unclear when changes in blood pressure (BP) and renal function become apparent and what role obesity and sex play. We hypothesized adolescents born preterm have higher BP and worse kidney function compared to term in an obesity- and sex-dependent manner.

METHODS

Cross-sectional analysis of 14-year-olds born preterm with very low birth weight (n = 96) compared to term (n = 43). We used generalized linear models to estimate the associations among preterm birth and BP, estimated glomerular filtration rate (eGFR), and ln (x) urinary albumin-to-creatinine ratio (ACR), stratified by overweight/obesity (OWO, body mass index (BMI) ≥ 85th percentile) and sex.

RESULTS

Compared to term, preterm-born adolescents had higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) (adjusted β (aβ) 3.5 mmHg, 95% CI - 0.1 to 7.2 and 3.6 mmHg, 95% CI 0.1 to 7.0), lower eGFR (β - 8.2 mL/min/1.73 m², 95% CI - 15.9 to - 0.4), and higher ACR (aβ 0.34, 95% CI - 0.04 to 0.72). OWO modified the preterm-term difference in DBP (BMI < 85th percentile aβ 5.0 mmHg, 95% CI 0.7 to 9.2 vs. OWO 0.2 mmHg, 95% CI - 5.3 to 5.6) and ACR (OWO aβ 0.72, 95% CI 0.15 to 1.29 vs. BMI < 85th percentile 0.17, 95% CI - 0.31 to 0.65). Sex modified the preterm-term ACR difference (female aβ 0.52, 95% CI 0.001 to 1.04 vs. male 0.18, 95% CI - 0.36 to 0.72).

CONCLUSIONS

Prematurity was associated with higher BP and reduced renal function that were detectable in adolescence. OWO and sex may modify the strength of these relationships.

Chronic nausea and orthostatic intolerance: Diagnostic utility of orthostatic challenge duration, Nausea Profile Questionnaire, and neurohumoral measures

BACKGROUND

Chronic nausea in pediatrics is a debilitating condition with unclear etiology. We aimed to define hemodynamic and neurohumoral characteristics of chronic nausea associated with orthostatic intolerance in order to improve identification and elucidate mechanism.

METHODS

Children (10-18 years) meeting Rome III criteria for functional dyspepsia with nausea and symptoms of orthostatic intolerance (OI) completed a Nausea Profile Questionnaire followed by prolonged (45 minutes rather than the traditional 10 minutes) head-upright tilt (HUT) (70° tilt up) test. Circulating catecholamines, vasopressin, aldosterone, renin, and angiotensins were measured supine and after 15 minutes into HUT. Beat-to-beat heart rate and blood pressure were continuously recorded to calculate their variability and baroreflex sensitivity.

KEY RESULTS

Within 10 and 45 minutes of HUT, 46% and 85% of subjects, respectively, had an abnormal tilt test (orthostatic hypotension, postural orthostatic tachycardia, or syncope). At 15 and 45 minutes of HUT, nausea was elicited in 42% and 65% of subjects respectively. Higher Nausea Profile Questionnaire scores correlated with positive HUT testing at 10 minutes (P = 0.004) and baroreflex sensitivity at 15 minutes (P ≤ 0.01). Plasma vasopressin rose 33-fold in subjects with HUT-induced nausea compared to twofold in those who did not experience HUT-induced nausea (P < 0.01).

CONCLUSIONS AND INFERENCES

In children with chronic nausea and OI, longer duration HUT elicited higher frequency of abnormal tilt testing and orthostatic-induced nausea. The Nausea Profile Questionnaire predicted the orthostatic response to tilt testing. Exaggerated vasopressin release differentiated patients with HUT-induced nausea (vs those without nausea), suggesting a possible mechanism for chronic nausea in childhood.

Abstract P306: Preterm Birth is Associated with Increased Blood Pressure and Increased Urinary Angiotensinogen in Young Adults

Introduction: Cardiovascular disease (CVD) is the leading cause of mortality and hypertension (HTN) is a major risk factor for CVD. Preterm birth is an emerging risk factor for both CVD and HTN, but the underlying mechanisms are poorly described. The renin-angiotensin system (RAS) plays a key role in HTN and CVD, and adolescents born preterm have higher blood pressure (BP) with a shift in the balance of the classical and alternative pathways of the RAS exhibited as increased angiotensin II and reduced angiotensin-(1-7) as compared to term-born adolescents. Although numerous factors influence the expression of angiotensins, the precursor protein angiotensinogen in the kidney is implicated in the development of HTN and CVD and may contribute to higher angiotensin II. As the status of renal angiotensinogen in individuals born preterm is unknown, we hypothesized that urinary angiotensinogen is increased in young adults born preterm as compared to their term-born peers.

Methods: We compared urinary excretion of angiotensinogen corrected for urine creatinine and systolic and diastolic BP in 142 young adults (mean age 19.9 years) born preterm with very low birth weight (<1500 g) to 32 young adults born term using Wilcoxon Rank-Sum test and t-test. We used generalized linear models to compare the ln(x) urinary angiotensinogen between the preterm and term groups adjusted for the potentially confounding factors race, maternal hypertensive pregnancy, and maternal smoking during pregnancy.

Results: Compared to term, subjects born preterm had higher median urinary angiotensinogen (0.02 μg/g, IQR 0.01 to 0.04 vs. 0.01 μg/g, IQR 0.004 to 0.01, p < 0.001) and higher mean systolic BP (111 mmHg, SD 11 vs. 106 mmHg, SD 10, p = 0.03). On crude and adjusted analyses urinary angiotensinogen was associated positively with preterm birth (crude β : 0.82, 95% CI 0.47 to 1.16; adjusted β : 0.79, 95% CI 0.39 to 1.18).

Discussion: In addition to higher BP, young adults born preterm demonstrated increased urinary angiotensinogen as compared to their term-born peers. Preterm birth may induce programming of the renal RAS leading to higher angiotensinogen and a higher angiotensin-to-angiotensin-(1-7) ratio, potentially contributing to the increased risk of HTN in individuals born preterm.

Abstract P396: Vitamin D Supplementation Improves Cardiovascular Response to Head Up Tilt in Adolescents Suffering from Syncope

Background: In previous work we identified a group of adolescents whose diagnostic workup for chronic unexplained nausea revealed underlying cardiovascular instability manifesting as orthostatic intolerance (OI) and syncope. These patients exhibited impairment in autonomic function and excessive release of catecholamines (Epi / NE) and vasopressin (AVP) upon head up tilt compared to pre tilt. They also had low vitamin D level that correlated with the severity of symptoms on tilt. In this pilot study we hypothesized that vitamin D supplementation to normal levels will improve the cardiovascular response to tilt and reduce NE/Epi and AVP release.

Methods: A cohort of seven Adolescents (mean age= 16.2 years) who are vitamin D deficient had a head up tilt at baseline and after two months of vitamin D supplementation (2000-5000 IU daily based on baseline level). Heart rate, blood pressure, NE/Epi and AVP were measured in supine and standing position. Total time on tilt was also recorded.

Results: As see in the table. Compared to baseline, vitamin D supplementation reduced the HR elevation post HUT and reduced NE/Epi baseline levels and ameliorated the elevation in AVP after HUT.

Conclusions: Vitamin D supplementation for two months restored vitamin D to normal levels and was associated with less nausea symptoms during tilt and lower level of baseline catecholamines. It was also associated with less release of NE/Epi and vasopressin post head up tilt and longer duration of standing on tilt table. These data provides evidence of potential therapeutic benefit of vitamin D supplementation for patients suffering from syncope who are vitamin D deficient

Abstract 135: Impaired Autonomic Function in Young Adults Born Preterm With Very Low Birth Weight is Associated With Elevated Serum Uric Acid Levels

Preterm birth increases the risk of cardiometabolic disease. We showed that prematurity induces programming effects that lead to elevated blood pressure (BP), higher serum uric acid, and impaired autonomic control characterized by reduced heart rate variability (HRV), baroreflex sensitivity (BRS), and elevated ratio of low frequency to high frequency power (LF/HF), a marker of sympathovagal balance. However, the relationships among these factors in subjects born preterm are undefined. Since uric acid has been shown to correlate with HRV in adult hypertensive subjects, we hypothesized that higher uric acid is associated with impaired autonomic function in subjects born preterm.

Methods: A cohort of 131 young adults born preterm was compared to a cohort of 26 born term (19.6 years). Serum uric acid was measured. BP and ECG were recorded continuously for analysis of autonomic function reflected in HRV and BRS. We used generalized linear models to estimate the association between uric acid and measures of HRV and BRS, adjusting for race, age at follow up, and BMI. The potential interaction between uric acid and preterm birth was tested by introducing an interaction term and, if suggestive of an interaction (p ≤ 0.1), estimates were calculated within strata (preterm & term).

Results: Compared to term, preterm participants had higher serum uric acid levels (5.2 mg/dL, IQR: 4.2, 6.2 vs 4.8 mg/dL, IQR: 3.9, 6.0) and lower HRV as measured by standard deviation of normal to normal RR intervals (71 ms, IQR: 54, 97 vs 80 ms, IQR: 55, 101). Across term and preterm groups combined, uric acid was inversely associated with BRS measured as HF alpha ( β : -0.12, 95% CI -0.20 to -0.03, p for interaction = 0.06). Assessment of interaction showed this association was significant in preterms only ( β : -0.15, 95% CI -0.24 to -0.06 vs 0.07, -0.17 to 0.30). Uric acid was positively associated with LF/HF ( β : 0.13, 95% CI 0.01 to 0.25, p for interaction=0.01).

Conclusions: Young adults born preterm had dampened parasympathetic control of heart rate and BP, and higher serum uric acid was associated with sympathovagal imbalance. The data suggest that alterations of uric acid metabolism associated with preterm birth may increase the risk of early cardiovascular disease in part by impairing autonomic control

Abstract P301: Heart Rate Variability is Associated with Future Global Cognitive Performance: the Multi-Ethnic Study of Atherosclerosis

Background: Low heart rate variability (HRV) is associated with major vascular risk factors for cognitive decline, including hypertension and cardiovascular disease (CVD). Therefore, we hypothesized that higher HRV during mid- to late-life is associated with better cognitive performance.

Methods: In a subset of participants from the Multi-Ethnic Study of Atherosclerosis (N = 2,961; aged 45-84 years; 55% female; 40% white, 22% African-American, 25% Hispanic, and 13% Chinese-American), we used multivariate linear regression to study the relationship of short-term HRV to global cognitive performance as measured by the Cognitive Abilities Screening Instrument (CASI; score range 0-100). Two measures of HRV, the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive differences (RMSSD), were computed at Exam 1 (2000-2002) and Exam 5 (2010-2012). CASI was administered at Exam 5.

Results: In age-, race-, sex- and education-adjusted models, Exam 1 SDNN was significantly associated with performance on the CASI ( β = 0.74 ± 0.22; P < 0.001). This association remained significant after adjustment for cardiovascular risk factors, including prevalent CVD, medication use, and APOE ε4 allele carriage ( β = 0.53 ± 0.23; P = 0.019). Furthermore, participants with highest quartile Exam 1 SDNN scored better than the adjusted mean CASI score (0.61 ± 0.22 points higher; P = 0.022), and 0.81 ± 0.29 points higher than other quartiles ( P = 0.006); participants in other Exam 1 SDNN quartiles scored similarly to each other and to the adjusted mean. In contrast, there were no associations between CASI score and Exam 5 SDNN, Exam 1 RMSSD, or Exam 5 RMSSD after adjustment for cardiovascular risk factors, and no interactions between HRV and race or APOE were present.

Conclusions: Highest quartile 10-year antecedent SDNN is associated with better global cognitive performance in a multi-ethnic population of middle-aged and elderly adults, independent of sociodemographic factors, traditional cardiovascular risk factors, APOE status, and prevalent CVD. These results suggest that mid- to late-life HRV may be an early predictor of future cognitive ability.

Improvements in Heart Rate Variability, Baroreflex Sensitivity, and Sleep After Use of Closed-Loop Allostatic Neurotechnology by a Heterogeneous Cohort

Background

Heart rate variability (HRV) is an indicator of dynamic adaptability of the autonomic nervous system. Few interventions target upstream, cerebral cortex components of the heart–brain system for autonomic management. We report changes in HRV and baroreflex sensitivity (BRS), associated with use of a noninvasive, closed-loop, allostatic, computer-guided, acoustic stimulation neurotechnology.

Methods

Over 5 years, 220 subjects with heterogeneous neurological, cardiovascular, and psychophysiological conditions consecutively enrolled in a naturalistic, single-arm study exploring clinical effects associated with use of the neurotechnology. Of those, 202 completed the study protocol and 160 had recordings adequate to analyze HRV and BRS. Mean age was 44.0 (SD 19.4), with 130 women. Participants received a mean of 16.1 (5.2) sessions, over 24.2 days (23.3), with 9.5 (3.8) actual intervention days. Sessions included real-time analysis of brain electrical activity and software algorithm-guided translation of selected frequencies into patterns of acoustic stimulation (audible tones of variable pitch and timing), to facilitate auto-calibration of neural oscillations. Outcomes including 10-min supine, at-rest recordings of blood pressure and heart rate, and inventories for insomnia (ISI) and depression (CES-D or BDI-II), were obtained at baseline and 15.3 (16.7) days after the last session.

Results

Compared to baseline, significant increases (all p < 0.001) were observed for measures of HRV across all participants including the mean percentage change for SDNN 24.2% (SE 0.04), and RMSSD, 42.2% (0.08), and BRS [Sequence Up, 55.5% (0.09), Sequence Down, 77.6% (0.23), and Sequence All, 53.7% (0.07)]. Significant improvements were noted in SAP, MAP, and DAP, as well as natural log of HF, and total power. Self-reported ISI was reduced (ISI, −6.4 points, SD 5.6, p < 0.001). The proportion reporting clinically significant depressive symptoms reduced from 48.2% at baseline to 22.1% at follow-up. Linear regression showed that rightward asymmetry predicted lower SDNN (p = 0.02). Exploratory analysis showed a trend for improved balance of temporal lobe high-frequency amplitudes over the course of initial sessions.

Conclusion

These findings indicate that use of a noninvasive, allostatic, closed-loop neurotechnology appears to have robust potential for public health efforts to support greater flexibility in autonomic cardiovascular regulation, through self-optimization of electrical activity at the level of the brain.

Successful use of closed-loop allostatic neurotechnology for post-traumatic stress symptoms in military personnel: self-reported and autonomic improvements

BACKGROUND

Military-related post-traumatic stress (PTS) is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology that produces real-time translation of dominant brain frequencies into audible tones of variable pitch and timing to support the auto-calibration of neural oscillations. We report clinical, autonomic, and functional effects after the use of HIRREM® for symptoms of military-related PTS.

METHODS

Eighteen service members or recent veterans (15 active-duty, 3 veterans, most from special operations, 1 female), with a mean age of 40.9 (SD = 6.9) years and symptoms of PTS lasting from 1 to 25 years, undertook 19.5 (SD = 1.1) sessions over 12 days. Inventories for symptoms of PTS (Posttraumatic Stress Disorder Checklist - Military version, PCL-M), insomnia (Insomnia Severity Index, ISI), depression (Center for Epidemiologic Studies Depression Scale, CES-D), and anxiety (Generalized Anxiety Disorder 7-item scale, GAD-7) were collected before (Visit 1, V1), immediately after (Visit 2, V2), and at 1 month (Visit 3, V3), 3 (Visit 4, V4), and 6 (Visit 5, V5) months after intervention completion. Other measures only taken at V1 and V2 included blood pressure and heart rate recordings to analyze heart rate variability (HRV) and baroreflex sensitivity (BRS), functional performance (reaction and grip strength) testing, blood and saliva for biomarkers of stress and inflammation, and blood for epigenetic testing. Paired t-tests, Wilcoxon signed-rank tests, and a repeated-measures ANOVA were performed.

RESULTS

Clinically relevant, significant reductions in all symptom scores were observed at V2, with durability through V5. There were significant improvements in multiple measures of HRV and BRS [Standard deviation of the normal beat to normal beat interval (SDNN), root mean square of the successive differences (rMSSD), high frequency (HF), low frequency (LF), and total power, HF alpha, sequence all, and systolic, diastolic and mean arterial pressure] as well as reaction testing. Trends were seen for improved grip strength and a reduction in C-Reactive Protein (CRP), Angiotensin II to Angiotensin 1-7 ratio and Interleukin-10, with no change in DNA n-methylation. There were no dropouts or adverse events reported.

CONCLUSIONS

Service members or veterans showed reductions in symptomatology of PTS, insomnia, depressive mood, and anxiety that were durable through 6 months after the use of a closed-loop allostatic neurotechnology for the auto-calibration of neural oscillations. This study is the first to report increased HRV or BRS after the use of an intervention for service members or veterans with PTS. Ongoing investigations are strongly warranted.

TRIAL REGISTRATION

NCT03230890 , retrospectively registered July 25, 2017.

Antenatal corticosteroids and cardiometabolic outcomes in adolescents born with very low birth weight

BackgroundExposure to antenatal corticosteroids (ANCS) is associated with adverse cardiometabolic outcomes in animal models; however, long-term outcomes in clinical studies are not well characterized. We hypothesized that exposure to ANCS would be associated with markers of increased cardiometabolic risk in adolescents born with very low birth weight (VLBW).MethodsIn an observational cohort of 186 14-year-old adolescents born with VLBW, we measured resting blood pressure (BP), BP response to cold, ambulatory BP, and anthropometrics; performed dual-energy X-ray absorptiometry; and analyzed blood samples for uric acid, cholesterol, glycated hemoglobin, and high-sensitivity C-reactive protein. Multivariate analyses were used to evaluate associations with ANCS, adjusting for race, sex, and maternal hypertensive pregnancy.ResultsThere were no ANCS group differences in BP measures or blood biomarkers. Compared with adolescents unexposed to ANCS, those exposed to ANCS were taller (exposed-unexposed mean difference 3.1 cm (95% confidence interval (CI) 0.7, 5.5)) and had decreased waist-to-height ratio (exposed-unexposed mean difference -0.03 (95% CI -0.058, -0.002)). Males exposed to ANCS had lower total cholesterol (exposed-unexposed mean difference -0.54 mmol/l (95%CI -0.83, -0.06)).ConclusionAmong adolescents born with VLBW, ANCS exposure was not associated with markers of increased cardiometabolic risk.

Abstract P484: Improved Heart Rate Variability, and Symptoms of Insomnia and Stress, With Use of a Closed-loop, Allostatic Neurotechnology in Law Enforcement Officers

Background: Law enforcement officers have decreased life expectancy, attributed to work-related exposure to traumatic stress and circadian disruption. Autonomic dysregulation is reported with traumatic stress, and chronic insomnia. Closed-loop therapies with real time monitoring for modulation of biological function offer a precision-guided, patient-centric strategy for brain-based therapies. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology using software generated algorithms to identify specific brain frequencies, and translate them in real time into audible tones, to support self-optimization of brain rhythms.

Objective: To evaluate benefits for autonomic function, and symptoms of insomnia and stress, in a relatively healthy cohort of law enforcement officers, who enrolled in an IRB-approved, open label feasibility study evaluating HIRREM for diverse neuropsychological disorders. Measures done before and after HIRREM included symptom inventories for insomnia (ISI), depression (CES-D), traumatic stress (PCL-C), anxiety (GAD-7), and perceived stress (PSS). Ten minute recordings of heart rate and blood pressure allowed analysis of baroreflex sensitivity (BRS) and heart rate variability (HRV).

Results: 7 participants (1 female), mean (SD) age 47 (4.5), received 10.7 (2.6) HIRREM sessions over 11.3 (4.6) days (7.3 in office days). Data were collected before, and 22.6 (1.8) days after HIRREM completion. Use of HIRREM was associated with significantly increased HRV measured as rMSSD [from 25.3 (7.0) to 43.1 (13.0) ms, p=0.02]. BRS measured by high frequency alpha index improved [from 11.3 (8.0) to 20.1 (11.0) ms/mmHg, p=0.03]. All symptom inventories improved significantly (p<0.05), even with the small cohort. There were no adverse events or drop outs.

Conclusion: These pilot data provide the first report of significant autonomic cardiovascular benefits, and associated symptom improvements, with use of a closed-loop, allostatic therapy for a cohort of sworn law enforcement officers. Further studies are warranted to test the efficacy of this technology in a larger law enforcement cohort

Abstract P483: Healing a Broken Heart Using a Closed-loop, Allostatic, Neurotechnology: A Case Study in a Patient Suffering From Takotsubo Syndrome

Background: Stress cardiomyopathy or Takotsubo syndrome (TS) is an acute, reversible disorder of the heart characterized by left ventricular dysfunction, usually triggered by a stressful event. Excessive sympathetic excitation and shift in symapthovagal balance are proposed as mechanisms. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, neurotechnology using software algorithms to identify specific brain frequencies, translating them in real time into audible tones, to support self-optimization of brain rhythms and improve autonomic balance.

Objective: To evaluate benefits of HIRREM on autonomic function and symptom reduction in a 55 year old female enrolled in an IRB-approved open label feasibility study, after TS diagnosis.

Results: The participant received 13 HIRREM sessions over 11 days (9 in office days). Data were collected before, and 21 days after HIRREM completion. Baseline brain patterns had prominent right dominance at temporal lobes (sympathetic pattern), which balanced by the end of the sessions. Cardiovascular autonomic balance also shifted away from sympathetic towards parasympathetic. This was seen as reduced LF/HF ratio (from 1.89 to 0.63), increased heart rate variability (rMSSD from 27 to 40.8 ms), and baroreflex sensitivity (from 11.8 to 24.4 ms/mmHg). Blood pressure dropped from 132/90 to 121/88 with no change in heart rate despite discontinuation of her ACE inhibitor medication due to her BP being “too low.” HIRREM use was also associated with clinically meaningful improvements in multiple symptom inventories including insomnia (ISI) from 15 to 6, depression (CES-D) from 16 to 2, anxiety (GAD-7) from 18 to 2, and perceived stress scale (PSS) from 30 to 14. The patient reported resolution of a feeling of heaviness and discomfort in the chest after starting HIRREM sessions.

Conclusion: These data provide the first report of potential cardiovascular benefits of a non- pharmacological therapy to patients suffering from broken heart syndrome.

Abstract P123: Obesity and Alterations in Renal Function in Adolescents Born Preterm With Very Low Birth Weight

Background: Survival of children born preterm has improved dramatically, but prematurity and low birth weight may increase the risk of renal disease. Children born preterm have a lower glomerular filtration rate (GFR) and higher blood pressure (BP) compared to term peers, but compounding risk factors for renal disease among children born preterm remain poorly characterized. Indeed, patient factors such as obesity may influence the development of kidney disease. Thus, we hypothesize that obesity is associated with decreased renal function in adolescents born preterm with very low birth weight.

Methods: We measured systolic and diastolic BP, serum creatinine, and urine albumin at age 14 years in 124 adolescents born preterm with very low birth weight (mean birth weight 1056 g). We calculated the GFR by the Schwartz equation and the albumin-to-creatinine ratio (ACR) on morning urine samples. We used generalized linear models to estimate the association between obesity [body mass index (BMI) ≥95 th %ile for age and sex, n= 27] and renal function, adjusting for race, sex, maternal smoking during pregnancy, and birth weight z-score.

Results: Obesity was associated with higher systolic BP ( p =0.03). Compared to adolescents with BMI <95 th %ile, those with obesity had lower GFR ( β : -14.68 mL/min/1.73 m 2 , 95% CI -26.8 to -2.55). Adjustment for covariates attenuated this relationship ( β : -10.05 mL/min/1.73 m 2 , -21.12 to 1.03). Adolescents with obesity had a higher serum creatinine, but this did not reach statistical significance ( β : 0.05 mg/dL, -0.01 to 0.11). There was no difference in the ACR ( β : -0.05, -0.13 to 0.02).

Conclusions: Obese adolescents born preterm with very low birth weight exhibit higher systolic BP and lower GFR compared to those with BMI <95 th %ile, though the statistical significance of the relationship with GFR weakened after adjustment for possible confounders. Importantly, sex was a significant confounder that may influence the relationship between GFR and obesity, as female adolescents had significantly lower GFR than male adolescents. While obesity should be avoided, other factors should be considered that may contribute to worse renal function in adolescents born preterm with very low birth weight.

Abstract P204: Gender-specific Relationships Between Plasma Levels of Endocannabinoids and Vagal and Sympathetic Control of Heart Rate in Normotensive Obese Older Adults

Previous studies in obese individuals indicate higher circulating endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) than in lean counterparts. However, the association between plasma endocannabinoids and autonomic control of blood pressure and heart rate has not been assessed in obesity. In a sample of normotensive, obese older adults we analyzed plasma content of the endocannabinoids AEA and total AG using mass spectrometry and examined correlations with various indices of spontaneous sympathovagal activity. Spontaneous baroreflex sensitivity (BRS) for heart rate control was calculated by spectral analysis of arterial pressure (AP) time (Sequence [Seq] Up, Seq Down and Seq All) and frequency (low-frequency [LF] and high-frequency [HF] α) domains from continuous resting AP recordings. In addition, time domain analysis was used to calculate heart rate variability (HRV) and blood pressure variability, indices of cardiac vagal tone and vascular sympathetic tone, respectively. The sample included 8 males and 17 females with a mean age of 68.4 ± 0.6 years, a mean body mass index of 35.0 ± 0.8 kg/m 2 , and mean AP of 101.0 ± 2.2 mmHg. Across the complete sample, we report a significant inverse correlation between plasma AG content and HFα, an index of the vagally-mediated parasympathetic spontaneous BRS ( r = -0.50, P < 0.05). We further report a significant inverse correlation between plasma AG and the vagal spontaneous BRS (Seq Up) in males ( r = -0.87, P < 0.01) but not in females. However, in females but not males we found significant positive relationships between AEA and LFα, an index of sympathetic spontaneous BRS ( r = 0.49, P < 0.05), and AEA and HRV ( r = 0.50, P < 0.05). These results are consistent with a role for the endocannabinoid system to modulate autonomic control of the circulation in populations at risk for hypertension and cardiovascular disease, and suggest gender differences that have yet to be elucidated.

Abstract 145: Central Angiotensin-(1-7) Treatment Attenuates ERK 1/2 Expression and Oxidative Stress in the Dorsal Medulla of Betamethasone-Exposed Sheep That Associates With Improved Blood Pressure and Baroreflex Sensitivity

Fetal exposure to betamethasone (BMX) that is routinely administered to women threatening premature delivery may lead to deleterious long-term effects on the central cardiovascular system. In the adult offspring of BMX-exposed sheep, we demonstrate increased mean arterial pressure (MAP) and attenuated baroreflex sensitivity (BRS). These responses are associated with dysregulation of the brain renin-angiotensin system (RAS) reflecting lower medullary expression of Angiotensin-(1-7) [Ang-(1-7)] and its beneficial actions. Moreover, mitogen activated protein kinase (MAPK), a key signaling cascade implicated in cardiovascular dysfunction and stimulation of oxidative stress is increased in the brain dorsomedial medulla (DMM). We hypothesize that loss of Ang-(1-7) tone with BMX is an underlying mechanism for the programming effects to increase MAPK and oxidative stress. Thus, we examined whether intracerebroventricular treatment with Ang-(1-7) that lowers MAP and improves BRS will impact MAPK signaling and downstream generation of reactive oxygen species (ROS). MAPK activation as detected by the ratio of phospho-ERK 1/2 to total ERK densities was significantly reduced by >80% in the Ang-(1-7)-treated BMX sheep as compared to the CSF-treated BMX controls (0.20 ± 0.07 vs 1.04 ± 0.31; p = 0.01, N=4/group). Ang-(1-7) treatment was associated with lower expression of two indices of ROS including 4-HNE (0.23 ± 0.03 vs. 0.31 ± 0.03 p = 0.03) and protein carbonyl content (9.95 ± 0.69 vs 15.94 ± 3.49; p = 0.07). Finally, regression analysis revealed that phospho-ERK 1/2 expression positively correlated with ROS (4-HNE) (r = 0.816; p = 0.01). The 4-HNE content also trended positively with MAP (r = 0.659, p = 0.08), but exhibited a negative correlation with BRS (r = -0.831; p = 0.01). We conclude that reduced central Ang-(1-7) tone may contribute to the chronic dysregulation of the MAPK and ROS signaling pathways within the DMM following BMX exposure. Moreover, Ang-(1-7) may constitute a potential therapeutic approach to improve autonomic dysfunction by attenuating both MAPK and ROS pathways. HD 047584.

Abstract P485: Use of a Noninvasive, Closed-loop, Allostatic, Neurotechnology Reduced Blood Pressure and Improved Heart Rate Variability in a Pre-hypertensive Cohort

Background: Prehypertension increases risk for hypertension and cardiovascular disease, but effective interventions have not been defined. Disturbed central control of cardiovascular regulation due to trauma, stress, anxiety or other causes can lead to prehypertension and impaired heart rate variability (HRV). High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology using software algorithms to identify specific brain frequencies, and translate them in real time into audible tones, to support self-optimization of brain rhythms.

Objective: To evaluate the benefits of this nontraditional therapy on BP and autonomic function, subjects with untreated systolic BP of 120 to 139 or diastolic BP of 80 to 90 mmHg at baseline, who had enrolled in an IRB-approved open label feasibility study evaluating HIRREM for diverse neuropsychological disorders.

Results: 66 participants (40 female), mean (SD) age 43.3 (16.5), received 16 (5.7) HIRREM sessions over 22.4 (19.2) days, (9.5 (4.2) days with sessions). Data were collected before, and 14.4 (16.6) days after HIRREM completion. Use of HIRREM was associated with significantly reduced systolic (from 127.5 (8.0) to 122.9 (14.0) mmHg, p=0.011), and diastolic (from 82.0 (8.0) to 78.0 (9.0) mmHg, p= 0.014) arterial pressure, with no change in heart rate. HRV measured as SDNN increased (from 42.0 (17.0) to 50.0 (28.0) ms, p=0.002). Baroreflex sensitivity measured by sequence method improved (from 13.2 (8.0) to 17.2 (12.0) ms/mmHg, p=0.0001), with a trend for reduced sympathovagal tone measured by LF/HF ratio (from 2.5 (2.2) to 2.0 (1.8), p=0.068). There were no adverse events.

Conclusion: These data provide the first report of significant cardiovascular benefits of a closed-loop allostatic therapy for prehypertension. Blood pressure reduction and HRV improvement may prevent progression to more serious cardiovascular symptoms and diseases. Further studies are indicated to investigate the mechanism of the benefits associated with this promising intervention.

Abstract 051: Influence of Sex and Obesity on the Effect of Preterm Birth on the Renin-angiotensin System in Adolescents

Background: Preterm birth increases the risk of cardiovascular disease, but the underlying mechanisms are not known. Prematurity may induce programming effects that differentially influence the renin-angiotensin (Ang) system (RAS), particularly suppression of the beneficial Ang-(1-7) axis. Patient factors such as sex and obesity may influence the degree of RAS programming. Therefore, we hypothesize that preterm birth is associated with alterations in the RAS in adolescence in a sex and adiposity-dependent manner.

Methods: We evaluated a cohort of 175 adolescents born preterm and 51 term controls at age 14 years. We recorded systolic and diastolic BP z-scores, measured Ang II and Ang-(1-7) levels in plasma and urine, and calculated the peptide ratios. We applied generalized linear models to estimate the association between preterm birth and the RAS, adjusting for race, socioeconomic status, and maternal hypertension and smoking; the models were stratified by sex and overweight/obesity (body mass index ≥85 th %ile for age and sex).

Results: Mean systolic and diastolic BP z-scores were higher among those born preterm ( p <0.001 and p =0.03, respectively). Relative to term birth, preterm birth was associated with an increased plasma ratio of Ang II to Ang-(1-7) ( β : 4.42, 95% CI 1.52 to 7.32), decreased Ang II ( β : -5.16 pmol/L, -10.28 to -0.04), decreased Ang-(1-7) ( β : -5.38 pmol/L, -8.66 to -2.09), and a decreased urinary ratio of Ang II to Ang-(1-7) ( β : -0.13, -0.26 to -0.003). In stratified analyses, female sex ( β : -7.14 pmol/L, -11.03 to -3.24) and overweight/obesity ( β : -8.21 pmol/L, -12.51 to -3.91) were associated with greater reductions in plasma Ang-(1-7). Overweight/obesity was associated with a greater increase in the ratio of plasma Ang II to Ang-(1-7) ( β : +6.13, 0.58 to 11.68).

Conclusions: Circulating Ang-(1-7) was lower relative to Ang II in adolescents born preterm. This suggests fetal RAS programming may contribute to the increased risk of cardiovascular disease in those born preterm. We note an important influence of sex in that the decrease in Ang-(1-7) is intensified in girls. Moreover, obesity may confer a second physiologic insult through a higher Ang II/Ang-(1-7) that exacerbates the risk of cardiovascular disease, including hypertension.

Effects of supervised exercise and dietary nitrate in older adults with controlled hypertension and/or heart failure with preserved ejection fraction

Aerobic exercise training is an effective therapy to improve peak aerobic power (peak VO₂) in individuals with hypertension (HTN, AHA/ACC class A) and heart failure patients with preserved ejection fraction (HFpEF). High nitrate containing beetroot juice (BRJ) also improves sub-maximal endurance and decreases blood pressure in both HTN and HFpEF. We hypothesized that combining an aerobic exercise and dietary nitrate intervention would result in additive or even synergistic positive effects on exercise tolerance and blood pressure in HTN or HFpEF. We report results from two pilot studies examining the effects of supervised aerobic exercise combined with dietary nitrate in patients with controlled HTN (n = 26, average age 65 ± 5 years) and in patients with HFpEF (n = 20, average age 69 ± 7 years). All patients underwent an aerobic exercise training regimen; half were randomly assigned to consume a high nitrate-containing beet juice beverage (BRJ containing 6.1 mmol nitrate for the HFpEF study consumed three times a week and 8 mmol nitrate for the HTN study consumed daily) while the other half consumed a beet juice beverage with the nitrate removed (placebo). The main result was that there was no added benefit observed for any outcomes when comparing BRJ to placebo in either HTN or HFpEF patients undergoing exercise training (p ≥ 0.14). There were within-group benefits. In the pilot study in patients with HFpEF, aerobic endurance (primary outcome), defined as the exercise time to volitional exhaustion during submaximal cycling at 75% of maximal power output, improved during exercise training within each group from baseline to end of study, 369 ± 149 s vs 520 ± 257 s (p = 0.04) for the placebo group and 384 ± 129 s vs 483 ± 258 s for the BRJ group (p = 0.15). Resting systolic blood pressure in patients with HFpEF also improved during exercise training in both groups, 136 ± 16 mm Hg vs 122 ± 3 mm Hg for the placebo group (p < 0.05) and 132 ± 12 mm Hg vs 119 ± 9 mm Hg for the BRJ group (p < 0.05). In the HTN pilot study, during a treadmill graded exercise test, peak oxygen consumption (primary outcome) did not change significantly, but time to exhaustion (also a primary outcome) improved in both groups, 504 ± 32 s vs 601 ± 38 s (p < 0.05) for the placebo group and 690 ± 38 s vs 772 ± 95 s for the BRJ group (p < 0.05) which was associated with a reduction in supine resting systolic blood pressure in BRJ group. Arterial compliance also improved during aerobic exercise training in both the HFpEF and the HTN patients for both BRJ and placebo groups. Future work is needed to determine if larger nitrate doses would provide an added benefit to supervised aerobic exercise in HTN and HFpEF patients.

Clinical, hemispheric, and autonomic changes associated with use of closed-loop, allostatic neurotechnology by a case series of individuals with self-reported symptoms of post-traumatic stress

BACKGROUND

The objective of this pilot study was to explore the use of a closed-loop, allostatic, acoustic stimulation neurotechnology for individuals with self-reported symptoms of post-traumatic stress, as a potential means to impact symptomatology, temporal lobe high frequency asymmetry, heart rate variability (HRV), and baroreflex sensitivity (BRS).

METHODS

From a cohort of individuals participating in a naturalistic study to evaluate use of allostatic neurotechnology for diverse clinical conditions, a subset was identified who reported high scores on the Posttraumatic Stress Disorder Checklist (PCL). The intervention entailed a series of sessions wherein brain electrical activity was monitored noninvasively at high spectral resolutions, with software algorithms translating selected brain frequencies into acoustic stimuli (audible tones) that were delivered back to the user in real time, to support auto-calibration of neural oscillations. Participants completed symptom inventories before and after the intervention, and a subset underwent short-term blood pressure recordings for HRV and BRS. Changes in temporal lobe high frequency asymmetry were analyzed from baseline assessment through the first four sessions, and for the last four sessions.

RESULTS

Nineteen individuals (mean age 47, 11 women) were enrolled, and the majority also reported symptom scores that exceeded inventory thresholds for depression. They undertook a median of 16 sessions over 16.5 days, and 18 completed the number of sessions recommended. After the intervention, 89% of the completers reported clinically significant decreases in post-traumatic stress symptoms, indicated by a change of at least 10 points on the PCL. At a group level, individuals with either rightward (n = 7) or leftward (n = 7) dominant baseline asymmetry in temporal lobe high frequency (23-36 Hz) activity demonstrated statistically significant reductions in their asymmetry scores over the course of their first four sessions. For 12 individuals who underwent short-term blood pressure recordings, there were statistically significant increases in HRV in the time domain and BRS (Sequence Up). There were no adverse events.

CONCLUSION

Closed-loop, allostatic neurotechnology for auto-calibration of neural oscillations appears promising as an innovative therapeutic strategy for individuals with symptoms of post-traumatic stress.

TRIALS REGISTRATION

ClinicalTrials.gov #NCT02709369 , retrospectively registered on March 4, 2016.