Early onset neurocirculatory response to static handgrip is associated with greater blood pressure variability in women with posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is a psychiatric illness that is more prevalent in women, and accumulating evidence suggests a link between PTSD and future development of cardiovascular disease. The underlying mechanisms are unclear, but augmented sympathetic reactivity to daily stressors may be involved. We measured muscle sympathetic nerve activity (MSNA), blood pressure (BP), and heart rate responses in 14 women with PTSD and 14 healthy women (controls) during static handgrip (SHG) exercise to fatigue at 40% of maximal voluntary contraction (MVC). Two minutes of postexercise circulatory arrest (PECA) was followed immediately after SHG to fatigue. MVC and the time to fatigue during SHG did not differ between groups (both P > 0.05). At the first 30 s of SHG, women with PTSD showed augmented sympathetic neural [mean ± SD, ∆MSNA burst frequency (BF): 5 ± 4 vs. 2 ± 3 bursts/30 s, P = 0.02 and ∆MSNA total activity (TA): 82 ± 58 vs. 25 ± 38 arbitrary units/30 s, P = 0.004] and pressor (∆systolic BP: 10 ± 5 vs. 4 ± 3 mmHg, P = 0.003) responses compared with controls. However, MSNA and BP responses at fatigue and during PECA were not different between groups. More interestingly, the augmented initial neural and pressor responses to SHG were associated with greater awake systolic BP variability during ambulation in women with PTSD (MSNA BF: r = 0.55, MSNA TA: r = 0.62, and SBP: r = 0.69, all P < 0.05). These results suggest that early onset exercise pressor response in women with PTSD may be attributed to enhanced mechano- rather than metaboreflexes, which might contribute to the mechanisms underlying the link between PTSD and cardiovascular risk.NEW & NOTEWORTHY The novel findings of the current study are that women with posttraumatic stress disorder (PTSD) exhibited augmented sympathetic neural and pressor responses at the first 30 s of submaximal isometric muscle contraction. More interestingly, exaggerated neurocirculatory responses at the onset of muscle contraction were associated with greater ambulatory awake systolic blood pressure fluctuations in women with PTSD. Our findings expand the knowledge on the physiological mechanisms that perhaps contribute to increased risk of cardiovascular disease in such a population.

Reduced left ventricular diastolic function in women with posttraumatic stress disorder.

Women are two to three times more likely to develop posttraumatic stress disorder (PTSD) compared with men after exposure to a major trauma, and PTSD is associated with increased risk for cardiovascular disease in later life. The underlying mechanisms are unclear, but alterations in cardiac function may be involved. We hypothesized that women with PTSD have reduced left ventricular (LV) diastolic function. We studied 14 women with PTSD (PTSD group) and 14 women without PTSD (controls) using echocardiography Doppler to evaluate LV diastolic function, including peak velocities (E and A waves) in transmitral flow; diastolic, atrial kick, and systolic waveform velocities (e', a', and s') in tissue Doppler; the ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e'); and velocity of propagation (Vp) . Baseline characteristics including age, body size, blood pressure, and heart rate were not significantly different between the two groups. Compared with the control group, women with PTSD showed greater E/e' (controls vs. PTSD group: 7.0 ± 1.3 vs. 9.1 ± 1.3, P = 0.002) and smaller Vp (controls vs. PTSD group: 63.7 ± 11.3 vs. 47.5 ± 6.9 cm/s, P = 0.003). These results suggest that women with PTSD have reduced LV diastolic function, which may contribute, at least in part, to the increased risk of cardiovascular disease later in life.

Time course of changes in maternal left ventricular function during subsequent pregnancy in women with a history of gestational hypertensive disorders.

Women with a history of gestational hypertensive disorders (GHD) are at increased risk for developing perinatal cardiovascular complications (e.g., gestational hypertension, preeclampsia, etc.) in subsequent pregnancies. The underlying mechanisms remain uncertain, but impaired maternal left ventricular function may be one contributing factor for these complications. We evaluated the time course of changes in left ventricular function before, during, and after pregnancy in women with prior GHD. Sixteen women with a history of GHD (the high-risk group) and 25 women without such a history (controls) were enrolled. Resting hemodynamic and echocardiographic measurements were longitudinally performed before pregnancy, during early pregnancy (4-8 wk of gestation), during late pregnancy (32-36 wk of gestation), and postpartum (6-10 wk after delivery). Pregnancy outcomes were obtained after delivery. At prepregnancy, there was no difference in blood pressure and heart rate between the groups. Corrected isovolumic relaxation time was longer, E/ e' was larger, and Tei index was greater in the high-risk group than controls. Moreover, the rate of GHD during the study was significantly greater in the high-risk group than controls [odds ratio = 8.94 (95% confidence interval: 1.55-51.5), P = 0.007]. Multiple logistic regression analysis adjusted for age demonstrated that prepregnancy E/ e' was an independent predictor for GHD ( P = 0.017). Thus, women with a history of GHD have modestly impaired cardiac function prepregnancy compared with controls, which identifies an increased susceptibility to developing cardiovascular complications during a subsequent pregnancy.

Augmented venoarteriolar response with ageing is associated with morning blood pressure surge.

NEW FINDINGS: What is the central question of this study? The venoarteriolar response (VAR) contributes substantially to the maintenance of orthostatic tolerance in humans. Despite its importance in haemodynamic homeostasis, the impact of ageing on the VAR remains understudied. What is the main finding and its importance? Older adults exhibit an augmented VAR in response to leg dependency. The age-related augmentation of the VAR might be linked with progressive increases of peripheral vascular resistance with ageing. We found a modest but significant correlation between the leg VAR and the morning blood pressure surge in older adults. Augmented leg VAR might contribute to the blood pressure elevation in the early morning. ABSTRACT: The venoarteriolar response (VAR) is a non-adrenergic, non-baroreflex-mediated mechanism of vasoconstriction, which has been proposed to contribute ∼45% of the increase in total peripheral resistance during orthostasis. Despite its importance in human cardiovascular control during orthostatic stress, there is no information available regarding the impact of age and sex on the VAR or its role in diurnal blood pressure (BP) variation. We studied 33 (15 women) young (mean ± SD; 28 ± 4 years old) and 26 (12 women) older (71 ± 3 years old) healthy individuals. Brachial and femoral blood flow were measured using Doppler ultrasound. The percentage reduction in vascular conductance (blood flow/mean BP) during 4 min of limb dependency (35-40 cm below the heart level) was used to assess the VAR. The morning surge in BP was assessed using 24 h ambulatory BP monitoring. Peak VAR in the lower limb, but not in the upper limb, was significantly higher in the older than the younger adults (33 ± 4 versus 26 ± 6%, older versus young; P < 0.05). There was no sex difference in the VAR in either the young or the older group. A greater leg VAR was related to a greater morning surge in BP in older adults (r = -0.4, P = 0.02) but not in the young adults (r = -0.26, P = 0.1). Thus, advancing age enhances the VAR in the lower limb and is associated with the morning blood pressure surge in older adults. Sex does not affect this local axonal reflex in healthy humans.

Sympathetic neural and cardiovascular responses during static handgrip exercise in women with a history of hypertensive pregnancy.

PURPOSE: Women with a history of hypertensive pregnancy are at greater risk for future cardiovascular events; however, the mechanisms for this increased risk are unknown. Evidence suggests that an exercise stimulus unmasks latent hypertensive tendencies, identifying individuals at the greatest risk for developing cardiovascular disease. The current study examined the hypothesis that women with a hypertensive pregnancy history exhibit an augmented exercise pressor response. METHODS: Normotensive women with a history of healthy pregnancy (CON; n = 9) and hypertensive pregnancy (HP+; n = 12) were studied during the mid-luteal phase of the menstrual cycle. Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), and muscle sympathetic nerve activity (MSNA) were measured during a cold pressor test (CPT), and, following a sufficient period of recovery, during static handgrip to fatigue (SHG) and post-exercise circulatory arrest (PECA). RESULTS: The BP, HR, and MSNA responses to the CPT were similar between groups. The SBP response to SHG and PECA was similar between groups, but DBP and HR were significantly greater in HP+ women (both p < 0.05). MSNA burst frequency, but not burst incidence or total activity, tended to be elevated in HP+ women during the stressor (peak Δ from baseline 31 ± 13 vs. 23 ± 13 bursts/min; p for group = 0.06). CONCLUSION: Despite no clinical signs of cardiovascular disease or hypertension, women with a history of hypertensive pregnancy display an enhanced cardiovascular reactivity to an exercise stimulus compared to women with a healthy pregnancy history. This response may be indicative of impaired cardiovascular control that precedes the clinical manifestation of hypertension or cardiovascular events.

Asian women have attenuated sympathetic activation but enhanced renal-adrenal responses during pregnancy compared to Caucasian women.

Asians have a lower prevalence of hypertensive disorders of pregnancy than Caucasians. Since sympathetic overactivity and dysregulation of the renal-adrenal system (e.g. low aldosterone levels) have been found in preeclamptic women, we hypothesized that Asians have lower muscle sympathetic nerve activity (MSNA) and greater aldosterone concentrations during normal pregnancy than Caucasians. In a prospective study, blood pressure (BP), heart rate (HR), and MSNA were measured during supine and upright tilt (30 deg and 60 deg for 5 min each) in 9 Asians (32 ± 1 years (mean ± SEM)) and 12 Caucasians (29 ± 1 years) during pre-, early (≤8 weeks of gestation) and late (32-36 weeks) pregnancy, and post-partum (6-10 weeks after delivery). Supine MSNA increased with pregnancy in both groups (P < 0.001); it was significantly lower in Asians than Caucasians (14 ± 3 vs. 23 ± 3 bursts min(-1) and 16 ± 5 vs. 30 ± 3 bursts min(-1) in early and late pregnancy, respectively; P = 0.023). BP decreased during early pregnancy (P < 0.001), but was restored during late pregnancy. HR increased during pregnancy (P < 0.001) with no racial difference (P = 0.758). MSNA increased during tilting and it was markedly lower in Asians than Caucasians in late pregnancy (31 ± 6 vs. 49 ± 3 bursts min(-1) at 60 deg tilt; P = 0.003). Upright BP was lower in Asians, even in pre-pregnancy (P = 0.006), and this racial difference persisted during pregnancy. Direct renin and aldosterone increased during pregnancy (both P < 0.001); these hormones were greater in Asians (P = 0.086 and P = 0.014). Thus, Asians have less sympathetic activation but more upregulated renal-adrenal responses than Caucasians during pregnancy. These results may explain, at least in part, why Asian women are at low risk of hypertensive disorders in pregnancy.

Left ventricular remodeling and arterial afterload in older women with uncontrolled and controlled hypertension.

OBJECTIVE: The prevalence of hypertension increases with advancing age in women. Blood pressure control is more difficult to achieve in older women, and despite well-controlled blood pressure, the cardiovascular mortality remains high. However, the underlying mechanisms are not understood. METHODS: Nineteen women with uncontrolled hypertension on drug treatment (70 ±â€Š2 [SE] years, ambulatory awake blood pressure; 152 ±â€Š2/84 ±â€Š2 mm Hg), 19 with controlled hypertension (68 ±â€Š1 years, 128 ±â€Š2/71 ±â€Š2 mm Hg), and 31 healthy normotensive women (68 ±â€Š1 years, 127 ±â€Š1/73 ±â€Š1 mm Hg) were recruited. Participants were weaned from antihypertensive drugs and underwent 3 weeks of run-in before cardiac-vascular assessments. Left ventricular morphology was evaluated with cardiac magnetic resonance imaging. Arterial load and vascular stiffness were measured via ultrasound and applanation tonometry. RESULTS: Left ventricular mass normalized by body surface area was not different between hypertension groups (uncontrolled vs controlled: 50.0 ±â€Š1.7 vs 51.8 ±â€Š2.3 g/m), but it was lower in the normotensive group (41.7 ±â€Š0.9 g/m; one-way analysis of variance [ANOVA] P = 0.004). Likewise, central pulse wave velocity was not different between hypertension groups (11.5 ±â€Š0.6 vs 11.1 ±â€Š0.5 m/s) and lower in the normotensive group (9.1 ±â€Š0.3 m/s; 1-way ANOVA P = 0.0001). Total peripheral resistance was greater in uncontrolled hypertension (HTN) compared with normotensive group (2051 ±â€Š323 vs 1719 ±â€Š380 dyns/cm), whereas controlled HTN group (1925 ±â€Š527 dyns/cm) was not different to either groups. CONCLUSION: Regardless of current blood pressure control, hypertensive older women exhibited increased cardiac mass and arterial stiffness compared with normotensives. Future large-scale longitudinal studies are warranted to directly investigate the mechanisms for the high cardiovascular mortality among older hypertensive women with well-controlled blood pressure.

Cerebral blood flow regulation and cognitive function in women with posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is associated with structural and functional alterations in a number of interacting brain regions, but the physiological mechanism for the high risk of cerebrovascular disease or impairment in brain function remains unknown. Women are more likely to develop PTSD after a trauma than men. We hypothesized that cerebral blood flow (CBF) regulation is impaired in women with PTSD, and it is associated with impairment in cognitive function. To test our hypothesis, we examined dynamic cerebral autoregulation (CA) and cognitive function by using a transfer function analysis between arterial pressure and middle cerebral artery blood velocity and the Stroop Color and Word test (SCWT), respectively. We did not observe any different responses in these hemodynamic variables between women with PTSD ( n = 15) and healthy counterparts (all women; n = 8). Cognitive function was impaired in women with PTSD; specifically, reaction time for the neutral task of SCWT was longer in women with PTSD compared with healthy counterparts ( P = 0.011), but this cognitive dysfunction was not affected by orthostatic stress. On the other hand, transfer function phase, gain, and coherence were not different between groups in either the supine or head-up tilt (60°) position, or even during the cognitive challenge, indicating that dynamic CA was well maintained in women with PTSD. In addition, there was no relationship between cognitive function and dynamic CA. These findings suggest that PTSD-related cognitive dysfunction may not be due to compromised CBF regulation. NEW & NOTEWORTHY Cognitive function was impaired; however, dynamic cerebral autoregulation (CA) as an index of cerebral blood flow regulation was not impaired during supine and 60° head-up tilt in women with PTSD compared with healthy females. In addition, there was no relationship between cognitive function and dynamic CA. These findings suggest that the mechanism of PTSD-related cognitive dysfunction may not be due to CBF regulation.