Effects of ovarian steroids on immunoglobulin-secreting cell function in healthy women

To determine the effect of the ovarian hormone cycle on immunity, immunoglobulin-secreting cell (ISC) frequency and lymphocyte subsets were examined in the blood of healthy women. We found that immunoglobulin A (IgA)-secreting cells (IgA-ISC) were fourfold more frequent than IgG-ISC in peripheral blood mononuclear cells (PBMC). Further, the ISC frequency in PBMC was highest (P < 0.05) during the periovulatory stage of the menstrual cycle. Thus, endogenous ovarian steroids regulate the ISC frequency and this may explain why women are more resistant to viral infections and tend to have more immune-mediated diseases than men do.     

Effects of soy isoflavones on endothelial function in healthy postmenopausal women

OBJECTIVE: To evaluate the effects of soy isoflavone administration on endothelial function in healthy postmenopausal women. DESIGN: Sixty naturally postmenopausal women were randomly assigned to receive isoflavone or placebo tablets for 6 months. Endothelium-dependent vasodilatation was measured by brachial reactivity technique along with levels of plasma soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, P-selectin and soluble thrombomodulin, von Willebrand factor, and tissue plasminogen activator. Differences between endothelium-dependent and endothelium-independent vasodilatation were assessed by evaluating brachial reactivity parameters after reactive hyperemia and after sublingual administration of nitroglycerin; furthermore, in the active group, the effect of isoflavones was also evaluated during the intra-arterial infusion of N-monomethyl-L-arginine. Serum levels of lipids [high-density lipoprotein and low-density lipoprotein cholesterol, triglycerides and lipoprotein(a)] and hemostatic factors (prothrombin, fibrinogen, plasminogen activator inhibitor-1, and fibrin D-dimer) were also measured. To confirm the absorption of isoflavones, their blood concentrations were determined. RESULTS: Isoflavone treatment versus placebo was associated with a significant improvement in endothelium-dependent vasodilatation but had no impact on endothelial-independent arterial diameter and flow. Intra-arterial infusion of N-monomethyl-L-arginine inhibited the significant effect of isoflavones on endothelium-mediated vasodilatation. Furthermore, isoflavone group experienced statistically significant reductions in plasma concentrations of ICAM-1, VCAM-1, and E-selectin. Levels of soluble thrombomodulin, von Willebrand factor, tissue plasminogen activator, lipids, and hemostatic factors did not change significantly throughout the study in both groups. CONCLUSIONS: Our findings suggest a positive influence of soy isoflavones on endothelial function in healthy postmenopausal women as evidenced by an improvement in endothelium-dependent vasodilatation and a reduction in plasma adhesion molecule levels.     

Blunted cardiac autonomic responsiveness to hypoxemic stress in healthy older adults.

Supine resting cardiac dynamics and responses to steady-state hypoxemia were investigated in six healthy older (59-72 yrs) adults using coarse-graining spectral analysis of heart rate variability (HRV) and were compared to six young (22-29 yrs) adults studied previously (Lucy et al., 2000). End-tidal carbon dioxide pressure (PETCO2) was clamped at 1-2 mmHg above the usual resting value for 11 min of euoxia (PETO2 100 mmHg), followed by 22 min of hypoxia (PETO2 55 mmHg). During euoxia, vagally mediated harmonic and fractal power of HRV of older adults was minimal. Hypoxia induced an increase in ventilation, p < 0.01, and heart rate, p < 0.05. The heart rate increase (mean +/- SE) of 0.23 +/- 0.08 beats.min-1 per 1% decrease in arterial O2 saturation was 25% of that demonstrated previously by young subjects, p < 0.001. In older adults, HRV spectral power remained unchanged during hypoxia, providing further evidence of an age-related blunting of cardiac autonomic function.     

Spectral indices of cardiac autonomic function in obstructive sleep apnea.

Spectral analysis of heart rate variability (HRV) is useful as a noninvasive means of assessing autonomic function in patients with obstructive sleep apnea (OSA). However, standard spectral measures, such as the ratio of low-frequency to high-frequency power (LHR) and normalized high-frequency power (NHFP), can be confounded by the abnormal breathing patterns that occur during sleep. To circumvent this limitation, we employed an autoregressive modeling approach to partition the RR time-series into a component that is correlated with respiration and a respiration-independent component. From these components, we derived two new spectral indices: the modified LHR (MLHR) and the average gain relating respiration to RR changes (GRSA). Six normals and seven OSA patients were studied in relaxed wakefulness and stage 2 sleep; during sleep, the OSA patients were studied without and with continuous positive airway pressure (CPAP) therapy. All four spectral indices showed significant differences between OSA patients and normals in both wakefulness and sleep, although the changes in MLHR and GRSA were substantially larger and less variable: MLHR (p < 0.0003) and GRSA (p < 0.0001) vs. LHR (p < 0.005) and NHFP (p < 0.004). However, in the OSA subjects, LHR and NHFP were unchanged by CPAP. By contrast, CPAP produced a highly significant increase in GRSA (p < 0.0004), as well as a decrease in MLHR (p < 0.03). Thus, by compensating for the effects of breathing pattern differences, MLHR and GRSA unmasked the effects of CPAP therapy, which has been shown in previous studies to reduce sympathetic activity and increase vagal cardiac modulation.     

Effects of a short health education intervention on physical activity,arterial stiffness and cardiac autonomic function in individuals with moderate-to-high cardiovascular risk

ObjectiveThis study evaluated the effects of a short health education and counseling intervention program, in a primary healthcare setting, on daily physical activity (PA), arterial stiffness, and cardiac autonomic function in individuals with moderate-to-high risk of cardiovascular disease.MethodsThis was a parallel-group study with a 4-month-long intervention, plus 8 months of follow-up. 164 individuals with moderate-to-high cardiovascular risk were allocated to either an intervention (n = 87) or a control group (n = 77). The intervention consisted of 3 walking and face-to-face group sessions plus text messages. Primary outcome was daily PA (sedentary time, light and moderate-to-vigorous PA, all in min/day); secondary outcomes were arterial stiffness i.e., carotid-femoral pulse wave velocity (cfPWV, m/s)] and cardiac autonomic function [(i.e., standard deviation of all N-N intervals (SDNN, ms) and absolute high frequency (HF, ms²)].ResultsThere were not significant group*time interactions for sedentary time [−7.4 (7.6); p = 0.331)], light PA [4.4 (6.4); p = 0.491] or moderate-to-vigorous PA [0.1 (2.6); p = 0.938]. Considering secondary outcomes, there were not significant group*time interactions for cfPWV [0.09 (0.18); p = 0.592], Ln_SDNN [0.09 (0.06); p = 0.148], or Ln_HF [0.16 (0.14); p = 0.263].ConclusionThe program did not improve daily PA, arterial stiffness, or the autonomic cardiac function.Practice ImplicationsPrimary care staff should consider longer or other types of intervention to improve daily PA.     

Smoking, lung function, physical performance and latent coronary heart disease in presumably healthy middle-aged men

During a cardiovascular survey comprising 2014 presumably healthy men aged 40-59 years, latent (previously undetected) coronary heart disease (CHD), lung function and physical performance were related to differences in smoking habits. The survey examination classified 1 832 individuals as "normals" (without clinical signs/symptoms of CHD). Among the others, a strong supicion of CHD was found in 115, of whom 105 had diagnostic coronary angiography. No angiography was performed in another 35 individuals with slight, albeit typical angina pectoris. The remaining 42 men were excluded from this presentation for various reasons. The following findings were obtained: 1) in the 69 men with positive coronary angiography, the extent of coronary atheromatosis was positively related to the number of cigarettes smoked. 2) The smoking habits of the 35 individuals with slight angina pectoris but no angiography did not differ from those of the "normals". 3) Physical performance during a near maximal bicycle exercise test and lung function according to spirometry were strongly and negatively related to smoking (in "normals"). 4) Previous smokers and never-smokers among "normals" had almost identical lung function and physical performance.     

Effects of voluntary physical exercise on cardiac function and energetics in spontaneously hypertensive rats

The influence of voluntary physical exercise in running wheels on myocardial function, cardiac oxygen utilization and cardiovascular response to emotional stress was analysed in the spontaneously hypertensive rat. After 6 weeks of exercise, a significant increase in resting cardiac output was found, which was due to an elevation of stroke volume. However, voluntary training for 12 weeks had no effect on resting blood pressure or on the blood-pressure response to mental stress. Cardiac function was also examined in vitro. At a low aortic diastolic pressure, it was markedly augmented in trained spontaneously hypertensive rats. At high aortic diastolic pressure, maximal cardiac function was similar in the two groups. Myocardial oxygen consumption (mumol min-1 g-1) for a given level of external work was reduced in trained, compared with non-exercised control spontaneously hypertensive rats. Chronic physical exercise thus greatly improved myocardial function at a subnormal perfusion pressure, suggesting better nutritional supply to the myocardium, probably created by an increased capillary surface area.     

Effects of physical training on cardiac myosin ATPase activity.

Cardiac myosin from rats exercised 90 or 150 min daily for 8 wk was compared with the myosin from the hearts of matched sedentary controls. The Ca++-ATPase activity was increased 17 percent in rats exercised 90 min and 30 percent in rats exercised 150 min daily. In the exercised group 0.18 M KCl increased the myosin ATPase activity by 50 percent but had no effect in the control group. Ethylene glycol activated the Ca++-ATPase in control myosin preparations, but had no significant effect on myosin from conditioned hearts. Heavy meromyosin (HMM) from conditioned hearts had a higher Ca++-ATPase activity than from controls. Fluorescence with 8-anilinonaphthalene sulfonate (ANS) was increased 30 percent in HMM from conditioned hearts. The results suggest that the increased myosin ATPase activity in the hearts of exercised animals may be due to a local conformational change at or near the active site.     

Influences of natural menopause on psychological characteristics and symptoms of middle-aged healthy women

We investigated the psychological and symptom consequences of the natural menopause in a longitudinal study of 541 initially premenopausal healthy women. All women were given an extensive evaluation at baseline. After 3 years of follow-up, 69 women ceased cycling for 12 months; another 32 women had ceased cycling and had taken hormone replacement therapy for a total of 12 months. These women were reevaluated in a clinic examination identical with the baseline examination, as were 101 age-matched premenopausal control women. Comparison among groups at the baseline and follow-up examination showed that natural menopause led to few changes in psychological characteristics, with only a decline in introspectiveness and an increase in reports of hot flashes being apparent. We conclude that natural menopause did not have negative mental health consequences for the majority of middle-aged healthy women.     

Sex differences in cardiac autonomic function of depressed young adults

Background

Cardiac autonomic dysfunction has been proposed as an important contributing factor to the increased cardiovascular risk observed in major depression (MDD). However, the evidence regarding alterations in heart rate variability (HRV) in otherwise healthy depressed subjects has been inconclusive.

Methods

A case–control study in 50 treatment-naïve young adults with a first MDD episode without comorbid psychiatric disorders and 50 healthy control subjects was conducted. Time- and frequency-domain indexes of HRV were determined at baseline supine and after 5-min of orthostatic stress at 60°.

Results

There were no significant differences in the time- or frequency-domain variables of HRV between depressed patients and controls. However, a random-effect ANOVA model showed that during orthostatic stress depressed men had a reduced HRV and decreased parasympathetic activity compared to control subjects, while no differences were found between depressed women and controls.

Conclusion

These results suggest a sex-dependent relationship between major depression and cardiac autonomic dysfunction and provide one potential explanation for sex differences in the association of depressive symptoms with cardiovascular morbidity.     

Effects of the menstrual cycle on mood, neurocognitive and neuroendocrine function in healthy premenopausal women

BACKGROUND: Neurocognitive functioning may be impaired in the luteal phase of the menstrual cycle due to associated changes in hypothalamic-pituitary adrenal (HPA) axis function. This study examines the relationship between changes in neurocognition and HPA axis function in different phases of the menstrual cycle. METHOD: Fifteen female volunteers, free from psychiatric history and hormonal medication were tested twice, during mid-follicular and late-luteal phases in a randomized, crossover design. Mood, neurocognitive function, and basal cortisol and dehydroepiandrosterone (DHEA) were profiled. RESULTS: Relative to the follicular phase, verbal fluency was impaired in the luteal phase and reaction times speeded on a continuous performance task, without affecting overall accuracy. 'Hedonic' scores on the UWIST-MACL scale were decreased in the luteal phase. There was also evidence of changes in the function of the HPA axis, with 24 h urinary cortisol concentrations and salivary DHEA levels being significantly lower during the luteal phase. CONCLUSIONS: These data suggest that luteal phase HPA axis function is lower than in the follicular phase in premenopausal healthy women. This putative biological difference may be important for our understanding of the aetiopathogenesis of menstrually related mood change and neurocognitive disturbance.     

Effects of dietary copper on human autonomic cardiovascular function

Summary Heart rate and blood pressure responses during supine rest, orthostasis, and sustained handgrip exercise at 30% maximal voluntary contraction were determined in eight healthy women aged 18–36 years who consumed diets varying in copper and ascorbic acid content. Copper retention and plasma copper concentration were not affected by diet. Enzymatic, but not immunoreactive, ceruloplasmin was lower (p<0.05) after the low copper and high ascorbic acid diet periods. Diet had no effect on resting supine heart rates, orthostatic responses in heart rate and blood pressure, or standing resting blood pressure. Systolic and diastolic blood pressures were increased significantly (p<0.05) during the handgrip test at the end of the low copper and ascorbic acid supplementation periods. Also, the ratio of enzymatic to immunoreactive ceruloplasmin decreased significantly during these dietary treatments. The mean arterial blood pressure at the end of the handgrip test was negatively (p<0.0004) correlated with the ceruloplasmin ratios. These findings indicate a functional alteration in human blood pressure regulation during mild copper depletion.     

Classical conditioning of autonomic responses in alert and drowsy subjects.

The primary purpose of this experiment was to study classically conditioned autonomic responses of alert versus drowsy subjects. Sixty-nine subjects in conditioning and pseudoconditioning groups were subdivided into alert and drowsy groups on the basis of EEG recordings during conditioning trials, giving a total of four groups: conditioning-alert, conditioning-drowsy, pseudoconditioning-alert and pseudoconditioning-drowsy. Using the latency criterion to define responses, significant conditioning occurred only in the conditioning-alert group for the following measures: skin resistance anticipatory and UCS-omission responses, and finger plethysmograph anticipatory response. Both conditioning groups showed evidence of conditioned UCS-omission plethysmograph responses. Discussion centered primarily on (1) the implications of the results on the question of the feasibility of learning during sleep; and (2) the importance of including EEG recordings in studies of classically conditioned autonomic responses. The relationship between the various responses was also evaluated.     

Test of an orienting-reaction-recovery account of short-interval autonomic conditioning.

The electrodermal and plethysmographic components of the orienting reaction in 24 subjects were examined in a conditioning-analog arrangement (tones and lights patterned analogously to CS and UCS presentations in classical conditioning) in order to test the orienting-reaction-recovery (ORR) account according to which apparent short-interval autonomic conditioning (SIAC) can be completely accounted for by an ORR effect. The form of the test was to see whether ORR following change from a repeatedly presented forward ('CS-UCS') analog would exceed that to change from a backward ('UCS-CS') analog, as is the case in SIAC with CS-alone test trials following repeated CS-UCS versus UCS-CS pairings. The results did not support the ORR account, although they were shown to be consistent with the relevant experimental literature, when critically examined, and to provide internal evidence for the adequacy of the present test of this particular formulation of the ORR account of SIAC.     

Musculoskeletal capacity of middle-aged women and men in physical,mental and mixed occupations

Summary The musculoskeletal capacity of 44 women and 39 men, mean age 55.0±3.4 years, was studied at the beginning and end of a 3.5 year period. The measurements included anthropometrics, maximal isometric trunk flexion and extension strength, maximal isometric hand grip strength and back mobility. According to a job analysis the subjects were divided into three dominating work groups: physical, mental and mixed groups. The results showed significant changes in anthropometrics, maximal isometric muscle strength and in mobility. The body weight and body mass index among women and the body mass index among men increased significantly during the period. The body height and sum of the skinfolds had on the other hand decreased significantly for both women and men. Women showed significant decreases of 9% and 10% (p<0.05 andp<0.01) in isometric trunk flexion and extension strength, and an increase of 9% in back mobility (p<0.05). In mental work, most of the significant changes occurred among women. Men had significant decreases in isometric trunk flexion and extension, 22% and 16% respectively (p<0.001) and an increase of 13% in back mobility (p<0.001). The men doing physical work had most of the significant changes in musculoskeletal capacity. The results revealed accelerated changes in musculoskeletal capacity in middle-aged employees.