Relative burst amplitude of muscle sympathetic nerve activity is an indicator of altered sympathetic outflow in chronic anxiety.

Relative burst amplitude of muscle sympathetic nerve activity (MSNA) is an indicator of augmented sympathetic outflow and contributes to greater vasoconstrictor responses. Evidence suggests anxiety-induced augmentation of relative MSNA burst amplitude in patients with panic disorder; thus we hypothesized that acute stress would result in augmented relative MSNA burst amplitude and vasoconstriction in individuals with chronic anxiety. Eighteen participants with chronic anxiety (ANX; 8 men, 10 women, 32 ± 2 yr) and 18 healthy control subjects with low or no anxiety (CON; 8 men, 10 women, 39 ± 3 yr) were studied. Baseline MSNA and 24-h blood pressure were similar between ANX and CON ( P > 0.05); however, nocturnal systolic blood pressure % dipping was blunted among ANX ( P = 0.02). Relative MSNA burst amplitude was significantly greater among ANX compared with CON immediately preceding (anticipation) and during physiological stress [2-min cold pressor test; ANX: 73 ± 5 vs. CON: 59 ± 3% arbitrary units (AU), P = 0.03] and mental stress (4-min mental arithmetic; ANX: 65 ± 3 vs. CON: 54 ± 3% AU, P = 0.02). Increases in MSNA burst frequency, incidence, and total activity in response to stress were not augmented among ANX compared with CON ( P > 0.05), and reduction in brachial artery conductance during cold stress was similar between ANX and CON ( P = 0.92). Relative MSNA burst amplitude during mental stress was strongly correlated with state ( P < 0.01) and trait ( P = 0.01) anxiety (State-Trait Anxiety Inventory), independent of age, sex, and body mass index. Thus in response to acute stress, both mental and physiological, individuals with chronic anxiety demonstrate selective augmentation in relative MSNA burst amplitude, indicating enhanced sympathetic drive in a population with higher risk for cardiovascular disease. NEW & NOTEWORTHY Relative burst amplitude of muscle sympathetic nerve activity in response to acute mental and physiological stress is selectively augmented in individuals with chronic anxiety, which is a prevalent condition that is associated with the development of cardiovascular disease. Augmented sympathetic burst amplitude occurs with chronic anxiety in the absence of common comorbidities. These findings provide important insight into the relation between anxiety, acute stress and sympathetic activation.

Effect of acute heparin administration on glycocalyx thickness and endothelial function in healthy younger adults.

The endothelial glycocalyx is a dynamic, gel-like layer that is critical to normal vascular endothelial function. Heparin impairs the endothelial glycocalyx and reduces vascular endothelial function in a murine model; however, this has yet to be tested in healthy humans. We hypothesized that a single bolus dose of heparin would increase circulating glycocalyx components and decrease endothelial glycocalyx thickness resulting in blunted brachial artery vasodilation in healthy younger adults. Healthy adults (n = 19, aged 18-39 yr, 53% female) underwent measurements of the endothelial glycocalyx and vascular endothelial function at baseline and after a single bolus 5,000 U dose of heparin. The glycocalyx components syndecan-1 and heparan sulfate were measured from plasma samples using enzyme-linked immunosorbent assays. Glycocalyx thickness was determined as perfused boundary region (PBR) in sublingual microvessels using the GlycoCheck. Endothelial function was measured via ultrasonography and quantified as brachial artery flow-mediated dilation (FMD). Following acute heparin administration, there was no increase in syndecan-1 or heparan sulfate (P = 0.90 and P = 0.49, respectively). In addition, there was no change in PBR 4-7 µm (P = 0.55), PBR 10-25 µm (P = 0.63), or 4-25 µm (P = 0.49) after heparin treatment. Furthermore, we did not observe a change in FMDmm (P = 0.23), FMD% (P = 0.35), or plasma nitrite concentrations (P = 0.10) in response to heparin. Finally, time to peak dilation and peak FMD normalized to shear stress were unchanged following heparin (P = 0.59 and P = 0.21, respectively). Our pilot study suggests that a single bolus intravenous dose of heparin does not result in endothelial glycocalyx degradation or vascular endothelial dysfunction in healthy younger adults.NEW & NOTEWORTHY The endothelial glycocalyx's role in modulating vascular endothelial dysfunction with aging and disease is becoming increasingly recognized. This study presents novel findings that acute heparin administration is not a feasible method to experimentally degrade the endothelial glycocalyx and measure concurrent changes in vascular endothelial function in healthy humans. Alternative approaches will be needed to translate findings from preclinical studies and test the effects of acute endothelial glycocalyx degradation on vascular endothelial function in humans.

Low indoleamine 2, 3 dioxygenase (IDO) activity is associated with psycho-obstetric risk.

OBJECTIVES: Preeclampsia and depression in pregnancy are among the most prevalent obstetric disorders with no known cures. While depression and preeclampsia each increase risk for the other, shared mechansisms are unclear. One possibility is low levels of Indoleamine 2,3 dioxygenase (IDO), which links immune dysregulation and oxidative arterial damage resulting in poor vascular function in both preeclampsia and depression. We hypothesized low circulating IDO activity levels in pregnancy would correspond to poor vascular function and depression symptoms. STUDY DESIGN: In this nested case-control study, clinical, demographic, and biologic data from a cohort of pregnant women recruited to longitudinal studies measuring noninvasive vascular function and circulating factors were analyzed. MAIN OUTCOME MEASURE: IDO activity across all three trimesters of pregnancy was measured using a colorimetric assay. Carotid-femoral pulse wave velocity (cfPWV), a measure of arterial stiffness, was also assessed throughout gestation by non-invasive applanation tonometry. Depression symptoms were assessed in pregnancy via the validated patient health questionnaire 9 (PHQ9). RESULTS: Participants with low second and third trimester IDO activity had significantly decreased cfPWV. This association remained statistically significant when controlled for confounders such as BMI and chronic hypertension in the third but not second trimester. While PHQ9 scores were not associated with cfPWV differences, IDO activity was lower in moderate and severely depressed relative to non-depressed pregnant individuals. CONCLUSION: These results implicate IDO in arterial stiffness and depression symptoms, suggesting that decreased IDO may be a central target for improved psycho-obstetric health.

Effect of glycocalyx-targeted therapy on vascular function in older adults: a randomized controlled trial.

Advancing age increases cardiovascular disease risk, in part, because of impaired glycocalyx thickness and endothelial dysfunction. Glycocalyx-targeted therapies, such as Endocalyx Pro, could improve both glycocalyx thickness and endothelial function in older adults; however, this has yet to be tested. We hypothesized that Endocalyx Pro supplementation would increase glycocalyx thickness and endothelial function in older adults. Twenty-three older adults aged 66 ± 7 yr (52% female) were enrolled in a randomized, double-blind, placebo-controlled, parallel-arms study to investigate the effect of 12-wk Endocalyx Pro supplementation (3,712 mg/day) on glycocalyx thickness and endothelial function. Glycocalyx thickness was assessed using the GlycoCheck, and endothelial function was determined via brachial artery flow-mediated dilation (FMD). Between-group comparisons revealed Endocalyx Pro did not increase glycocalyx thickness in microvessels 4-25 µm (P = 0.33), 4-7 µm (P = 0.07), or 10-25 µm (P = 0.47) in diameter when compared with placebo. In addition, Endocalyx Pro did not significantly improve FMD [mean ratio (95%) confidence interval [CI]) for between-group comparisons, 1.16 (0.77-1.74); P = 0.48]. However, Endocalyx Pro improved FMD normalized to shear rate (SR) area under the curve [mean ratio (95% CI) for between-group comparisons, 2.41 (1.14,4.13); P = 0.001]. Moreover, Endocalyx Pro increased capillary glycocalyx thickness more than placebo in individuals not taking antihypertensive medication [mean difference (95% CI) for between-group comparison, -0.08 (-0.15, -0.01); P = 0.02]. Our pilot study suggests that Endocalyx Pro supplementation is feasible in older adults but has no measurable effect on overall glycocalyx thickness and FMD. However, Endocalyx Pro may have select effects on capillary glycocalyx thickness and FMD normalized to shear rate among older adults, but further investigation is warranted.NEW & NOTEWORTHY Endothelial glycocalyx thickness and vascular endothelial function decline with advancing age. Endocalyx Pro is a glycocalyx-targeted therapy that may improve endothelial glycocalyx thickness and vascular endothelial function in older adults. This study demonstrated that 12-wk Endocalyx Pro supplementation did not improve overall endothelial glycocalyx thickness or flow-mediated dilation in older adults; however, Endocalyx Pro did increase capillary glycocalyx thickness in individuals not taking antihypertensive medication and improve flow-mediated dilation normalized to the shear stimulus.

Postpartum ambulatory and home blood pressure monitoring in women with history of preeclampsia: Diagnostic agreement and detection of masked hypertension.

Women with a history of preeclampsia (hxPE) are at a four-fold higher risk for chronic hypertension after pregnancy compared with healthy pregnancy, but 'masked' hypertension cases are missed by clinical assessment alone. Twenty-four hour ambulatory blood pressure monitoring (ABPM) is the reference-standard for confirmation of hypertension diagnoses or detection of masked hypertension outside of clinical settings, whereas home blood pressure monitoring (HBPM) may represent a well-tolerated and practical alternative to ABPM in the postpartum period. The objectives of this study were to 1) assess concordance between ABPM and HBPM postpartum in women with a hxPE compared with healthy pregnancy controls and 2) evaluate HBPM in the detection of masked postpartum hypertension. Young women with a hxPE (N = 26) and controls (N = 36) underwent in-office, 24-h ABPM and 7-day HBPM 1-4 years postpartum. Chronic hypertension was more prevalent among women with a hxPE by all three blood pressure measures, but the prevalence of masked postpartum hypertension did not differ (36% vs 37%, P = 0.97). HBPM showed excellent agreement with ABPM (systolic: r = 0.78, intraclass coefficient [ICC] = 0.83; diastolic: r = 0.82, ICC = 0.88) and moderate concordance in classification of hypertension (κ = 0.54, P < 0.001). HBPM identified 21% of masked postpartum hypertension cases without false-positive cases, and HBPM measures among those with normotensive in-office readings could detect ABPM-defined masked hypertension (area under the curve [AUC] = 0.88 ± 0.06, P < 0.0001). The findings of the present study indicate that HBPM may be a useful screening modality prior or complementary to ABPM in the detection and management of postpartum hypertension.

Twenty-Four-Hour Blood Pressure Variability Is Associated With Lower Cognitive Performance in Young Women With a Recent History of Preeclampsia.

BACKGROUND: Women with a history of preeclampsia (hxPE) exhibit sustained arterial stiffness and elevated blood pressure postpartum. Aortic stiffness and 24-hour blood pressure variability (BPV) are associated with age-related cognitive decline. Although hxPE is related to altered cognitive function, the association between aortic stiffness and BPV with cognitive performance in young women with hxPE has not been investigated. The objectives of this study were to (i) test whether cognitive performance is lower in young women with hxPE and (ii) determine whether aortic stiffness and BPV are associated with cognitive performance independent of 24-hour average blood pressure. METHODS: Women with hxPE (N = 23) and healthy pregnancy controls (N = 38) were enrolled 1-3 years postpartum. Cognitive performance was assessed in domains of memory, processing speed, and executive function. Twenty-four-hour ambulatory blood pressure monitoring and carotid-femoral pulse wave velocity (cfPWV) were used to measure BPV and aortic stiffness, respectively. RESULTS: Women with hxPE had slower processing speed (-0.56 ± 0.17 vs. 0.34 ± 0.11 Z-score, P < 0.001) and lower executive function (-0.43 ± 0.14 vs. 0.31 ± 0.10 Z-score, P = 0.004) compared with controls independent of education, whereas memory did not differ. BPV and cfPWV (adjusted for blood pressure) did not differ between women with hxPE and controls. Greater diastolic BPV was associated with lower executive function independent of 24-hour average blood pressure and education in women with hxPE (r = -0.48, P = 0.03) but not controls (r = 0.15, P = 0.38). CONCLUSIONS: Select cognitive functions are reduced postpartum in young women with a recent hxPE and linked with elevated 24-hour diastolic BPV.

One-day acceptance and commitment therapy (ACT) workshop improves anxiety but not vascular function or inflammation in adults with moderate to high anxiety levels in a randomized controlled trial.

OBJECTIVE: Acceptance and Commitment Therapy (ACT) is a behavioral intervention demonstrating sustained improvements in anxiety in individuals with chronic anxiety and psychological distress. Because anxiety disorders are associated with the development of cardiovascular disease (CVD), we hypothesized that a novel 1-day ACT workshop would both lower anxiety and improve vascular function in persons with moderate/high anxiety. METHODS: In a randomized controlled study, 72 adults (age 33.9 ± 8.6 (SD) years) with baseline moderate/high anxiety completed a one-day ACT intervention (n = 44, age 33.9 ± 8.7 years) or control (n = 28, age 37.1 ± 10.1 years). Pre-specified secondary outcomes were measured over 12 weeks: aortic stiffness (carotid-femoral pulse wave velocity [cfPWV]), forearm vascular endothelial function (post-ischemic peak forearm blood flow [FBF] via plethysmography), and brachial artery flow-mediated dilation (FMD). Carotid artery stiffness (ß-stiffness index), and inflammatory markers (C-reactive protein and tumor necrosis factor-alpha) were also explored. RESULTS: Although the intervention had a significant and sustained effect on the primary outcome of anxiety as measured by the Beck Anxiety Inventory, the 1-day ACT workshop was not associated with improvement in vascular or inflammatory endpoints. The intervention was unexpectedly associated with increases in ß-stiffness index that were also associated with changing trait anxiety. CONCLUSION: Anxiety improvements did not translate into improvements in any of the vascular function outcomes. This may reflect a less-than-robust effect of the intervention on anxiety, failure in design to select those with vascular dysfunction, or not intervening on a relevant causal pathway. (Trial registration NCT02915874 at www.clinicaltrials.gov).

Beat-to-Beat Blood Pressure Variability in the First Trimester Is Associated With the Development of Preeclampsia in a Prospective Cohort: Relation With Aortic Stiffness.

Women with preeclampsia, a hypertensive disorder of pregnancy, exhibit greater beat-to-beat blood pressure variability (BPV) in the third trimester after clinical onset of the disorder. However, it remains unknown whether elevated BPV precedes the development of preeclampsia. A prospective study cohort of 139 women (age 30.2±4.0 years) were enrolled in early pregnancy (<14 weeks gestation). BPV was quantified by time domain analyses of 10-minute continuous beat-to-beat blood pressure recordings via finger photoplethysmography in the first, second, and third trimesters. Aortic stiffness (carotid-femoral pulse wave velocity) and spontaneous cardiovagal baroreflex sensitivity were also measured each trimester. Eighteen women (13%) developed preeclampsia. Systolic BPV was higher in all trimesters among women who developed versus did not develop preeclampsia (first: 4.8±1.3 versus 3.7±1.2, P=0.001; second: 5.1±1.8 versus 3.8±1.1, P=0.02; third: 5.2±0.8 versus 4.0±1.1 mm Hg, P=0.002). Elevated first trimester systolic BPV was associated with preeclampsia (odds ratio, 1.94 [95% CI, 1.27-2.99]), even after adjusting for risk factors (age, body mass index, systolic blood pressure, history of preeclampsia, and diabetes mellitus) and was a significant predictor of preeclampsia (area under the receiver operator characteristic curve=0.75±0.07; P=0.002). Carotid-femoral pulse wave velocity was elevated in the first trimester among women who developed preeclampsia (5.9±0.8 versus 5.2±0.8 m/s; P=0.002) and was associated with BPV after adjustment for mean blood pressure (r=0.26; P=0.005). First trimester baroreflex sensitivity did not differ between groups (P=0.23) and was not related to BPV (P=0.36). Elevated systolic BPV is independently associated with the development of preeclampsia as early as the first trimester, possibly mediated in part by higher aortic stiffness.

Elevated Muscle Sympathetic Nerve Activity Contributes to Central Artery Stiffness in Young and Middle-Age/Older Adults.

Muscle sympathetic nerve activity (MSNA) influences the mechanical properties (ie, vascular smooth muscle tone and stiffness) of peripheral arteries, but it remains controversial whether MSNA contributes to stiffness of central arteries, such as the aorta and carotids. We examined whether elevated MSNA (age-related) would be independently associated with greater stiffness of central (carotid-femoral pulse wave velocity [PWV]) and peripheral (carotid-brachial PWV) arteries, in addition to lower carotid compliance coefficient, in healthy men and women (n=88, age: 19-73 years, 52% men). We also examined whether acute elevations in MSNA without increases in mean arterial pressure using graded levels of lower body negative pressure would augment central and peripheral artery stiffness in young (n=15, 60% men) and middle-age/older (MA/O, n=14, 43% men) adults. Resting MSNA burst frequency (bursts·min-1) was significantly correlated with carotid-femoral PWV ( R=0.44, P<0.001), carotid-brachial PWV ( R=0.32, P=0.004), and carotid compliance coefficient ( R=0.28, P=0.01) after controlling for sex, mean arterial pressure, heart rate, and waist-to-hip ratio (central obesity), but these correlations were abolished after further controlling for age (all P>0.05). In young and MA/O adults, MSNA was elevated during lower body negative pressure ( P<0.001) and produced significant increases in carotid-femoral PWV (young: Δ+1.3±0.3 versus MA/O: Δ+1.0±0.3 m·s-1, P=0.53) and carotid-brachial PWV (young: Δ+0.7±0.3 versus MA/O: Δ+0.7±0.5 m·s-1, P=0.92), whereas carotid compliance coefficient during lower body negative pressure was significantly reduced in young but not MA/O (young: Δ-0.04±0.01 versus MA/O: Δ0.001±0.008 mm2·mm Hg-1, P<0.01). Collectively, these data demonstrate the influence of MSNA on central artery stiffness and its potential contribution to age-related increases in stiffness of both peripheral and central arteries.