Healthy Elderly Men Research Articles

Three-week sprint interval training (SIT) reduces cell-free DNA and low-frequency fatigue but does not induce VO2max improvement in older men.

This study aimed to investigate the impact of sprint interval training (SIT) on both the acute and 3-week modulations of cell-free DNA (cfDNA), as well as its association with neuromuscular fatigue and physical performance in healthy young and old men. Ten young (20-25year old) and nine elderly (63-72year old) healthy men performed nine SIT sessions consisting of 4-to-6-all-out cycling repetitions of 30s interspaced with 4-min rest intervals. We compared the maximal voluntary contractions torque, central activation ratio, low-frequency fatigue (LFF), and cfDNA concentrations between the groups before, immediately after, 1h after, and 24h after the first and ninth SIT sessions. The plasma cfDNA levels were increased post-exercise (from 1.4 ± 0.258 to 1.91 ± 0.278ng/ml (P < 0.01) on a log10 scale), without significant differences between the groups. However, older individuals showed a slight decrease in the baseline cfDNA values, from 1.39 ± 0.176 to 1.29 ± 0.085ng/ml on a log10 scale, after 3weeks (P = 0.043). Importantly, the elevation of the post-exercise cfDNA values was correlated with an increase in LFF in both groups. Three weeks of SIT induced an improvement in the recovery of LFF (main session effect, P = 0.0029); however, only the young group showed an increase in aerobic capacity (VO2max) (from 40.8 ± 6.74 to 43.0 ± 5.80ml/kg/min, P = 0.0039). Three weeks of SIT diminished the baseline cfDNA values in the old group, together with an improvement in the recovery of LFF. However, VO2max was increased only in the young group.

Intersectional Perspective on Factors Influencing Healthy Ageing Amongst Older New Zealand Men: An Exploratory Mixed Methods Study

Little is known about how New Zealand men understand their health and wellbeing as they age and what are the determinants of their healthy ageing. Contiguous and exploratory sequential mixed methods study were conducted with the collection of both focus group and survey data. Methodologically, this abductive process was incorporated within an intersectional framework, providing a comprehensive picture of healthy aging in men across life stages and socioeconomic statuses. Integrated results revealed that for respondents the most significant factors influencing their healthy aging were, life engagement purpose, substance misuse, and masculinity norms. This article contributes to mixed methods research by providing practical applications of incorporating the intersectional model to enhance rigor in designing, conducting, and interpreting mixed methods research.

Abstract 16954: Sex Differences in Cardiac and Vascular Function With Healthy Aging: Implications for Greater Risk of HFpEF in Women

Introduction: Mechanisms mediating the disproportionate risk for heart failure with preserved ejection fraction (HFpEF) in women are poorly understood. Impaired stroke volume (SV) reserve, increased afterload, arterial and left ventricular (LV) stiffness contribute to exercise intolerance in HFpEF. It is unknown whether subclinical changes in these measures predispose women to HFpEF; therefore, we compared resting and exercise cardiovascular structure and function across age in healthy men and women. Methods: We studied 192 sedentary normotensive, non-obese adults (53% female; age: 58 ± 13 [20-90] years) at rest, during sub- and maximal exercise. We measured systolic blood pressure (SBP; electrosphygmomanometry) and aortic stiffness (carotid-femoral pulse wave velocity; aPWV). Myocardial stiffness was assessed as the slope of individual pressure-volume (right heart catheterization-echocardiography) curves generated by graded LV loading and unloading. SV was calculated from cardiac output (Q˙c; C 2 H 2 rebreathe)/heart rate to assess afterload (Ea; SBP/SV) and SV reserve (% change from rest) during exercise. Data were compared via two-way ANOVA (age*sex). Results: There was no significant age*sex interaction for aPWV, SV reserve, resting or maximal SBP, or myocardial stiffness; however, there was a main effect for sex with higher myocardial stiffness in women (Figure). aPWV and SV reserve were not different between sexes (p=0.349, p=0.940). Maximal exercise SBP was lower in women, but a similar proportion of each sex had an exaggerated maximal exercise SBP (Men: &gt;210; Women: &gt;190 mmHg; 28% vs 35%, χ 2 =0.290). Peak exercise afterload was higher in women (Figure) due to lower SV. Conclusions: Increased risk for HFpEF in women may be driven in part by greater myocardial stiffness throughout the aging process. Sex related abnormalities in afterload were most prominent with exercise in women, which may predispose to LV hypertrophy and increased stiffness.

14 A Potential Behavioral Sign for Detection of Mild HIV-Related Neuropsychological Impairment

Objective:Even though the severity of HIV-associated neurocognitive disorders (HAND) has decreased with the introduction of combination antiretroviral therapy, mild forms of HAND remain prevalent. Many HIV-infected individuals live alone, so mild cognitive impairments are easily missed. It is important to check their neurocognitive and everyday functions during hospital visits; however, it is challenging for Japanese clinicians because many hospitals do not have enough clinical psychologists or neuropsychologists. Additionally, neuropsychological (NP) test results may not detect those mild cognitive impairments. A micro error has been given more attention as a new behavioral sign of the early stages of cognitive decline, especially among people with Mild Cognitive Impairment (MCI). The current study aimed to 1) develop a touch-panel HAND screening battery and 2) evaluate if the micro errors could differentiate individuals with HAND from their counterpart healthy individuals.Participants and Methods:Forty HIV-infected men (age: 49.0±8.51 years old, education: 18.5±2.17 years) and 44 healthy men (age: 45.4±8.49 years old, education: 14.4±2.27 years) completed the touch-panel HAND screening battery which assessed six NP domains by seven subtests, everyday functions, and depression. A micro error is defined as a subtle action disruption or hesitation occurring immediately before making final actions. We evaluated the micro errors in short-term memory (STM) and long-term memory (LTM) of verbal learning tests (VLT).Results:Mann Whitney U tests revealed that the HIV+ group made significantly more micro errors on both STM (HIV+: 1.45±0.90 times, Healthy: 0.52±0.84 times) and LTM (HIV+: 1.85±0.73 times, Healthy: 1.29±0.71 times) than the healthy group (STM: W=1362, p&lt; .001, Effect Size (EF)= .548; LTM: W=1199.5, p= .002, EF= .363). An independent samples T-test showed that the HAND group made significantly more micro errors than the non-HAND group (t=1.822, p= .038, ES= .595) on STM; moreover, the Asymptomatic Neurocognitive Impairment (ANI) group made significantly more micro errors than the healthy group (W=446, p&lt; .001, ES= .689). On LTM, no significant micro error differences between HAND and non-HAND (W=184.5, p= .539, ES= -.189) nor between ANI and healthy group (W=327.5, p= .103, ES= .241) were found.Conclusions:The present study suggests that a novel behavioral measure, micro errors, may be able to help detect even the mildest form of HAND, ANI. Given that the touch-panel HAND screening battery consists of NP and IADL tests, it is important to evaluate micro errors on these various measures. Additionally, the touch-panel screening battery requires minimal administrative staff involvement, which could be beneficial for busy HIV clinicians.

Four minutes of capacitive and resistive electric transfer therapy increased jump performance

ABSTRACTCapacitive and resistive electric transfer (CRET) therapy can improve flexibility and increase muscle activity and may be useful as a warm-up technique. This study examined the effects of short-time CRET on jump performance. Thirty healthy men (age range, 20–40 years) were randomly divided into passive (n = 15) and active (n = 15) warm-up groups. The participants and statisticians were blinded to the participant allocation. The passive warm-up group underwent 4 min of CRET therapy on their posterior lower legs. The active warm-up group performed stretching and jogging for 4 min. Calf muscle temperature and rebound jump (RJ) index were measured before and after the intervention. The mean (± standard deviation) muscle temperature increased by 2.0 ± 0.5°C and 1.4 ± 0.6°C in the passive and active warm-up groups, respectively (p < 0.05). RJ index increased significantly in both groups (p < 0.05). Therefore, passive warm-up using CRET may help avoid energy loss while increasing the muscle temperature in a short time when compared with traditional active warm-up techniques.

The Effect of Bodyweight Support and Incline Running on Triceps Surae Electromyographic Activity

Body weight support (BWS) and incline running (IR) are commonly used either during rehabilitation or during training separately, with many positive effects on athletes’ performance and rehabilitation. The aim of the present study was to investigate the interaction between bodyweight support and incline running on the electromyographic activity of the triceps surae and compare it to flat running. In eighteen healthy men (age: 20.3 ± 1.2 years, body weight: 70.2 ± 4.8 kg, body height: 179.6 ± 5.4 cm), the changes in electromyographic activity (EMGA) during a 10 min run with BWS (15% or 30% of body weight; in different occasions) and IR at 7%, as well as jumping performance and gait spatiotemporal parameters, were evaluated. A lower Rating of Perceived Exertion and a significant decrease in the size of the Vastus Lateralis (VL) (33.4%), Soleus (SOL) (17%), and Gastrocnemius Lateralis (GL) EMGA (28.5%, p &lt; 0.05) but not in Gastrocnemius Medialis (GM) (10.5%, p &gt; 0.05), was observed during BWS30% at 7% slope compared to flat running. Also, low-frequency fatigue of the quadriceps was induced only after running without BWS on a 7% slope (p = 0.011). No changes were found in jumping performance (p = 0.246) and gait spatiotemporal parameters (p &gt; 0.05) except for flight time (p &lt; 0.006). In conclusion, running with a slope of 7% and 30% of BWS can result in EMG activity comparable to that observed during level running. This method can also be used in prevention and rehabilitation training programs without creating fatigue.

The effect of 24-hour sleep deprivation and anaerobic exercise on the expression of BAX, BCL2, BMAL1 and CCAR2 genes in peripheral blood mononuclear cells after L-arginine supplementation

Sleep deprivation disrupt the circadian clock and exercise performance. Defective oxidative stress caused by sleep deprivation may affect the expression of genes involved in cell apoptosis. Since a number of studies have shown the anti-apoptotic effect of L-arginine, so the aim of this study was to evaluate the effect of eight weeks of L-arginine supplementation on the expression of brain and muscle ARNT-like protein 1 (BMAL1), cell cycle and apoptosis regulator 2 (CCAR2), and BAX and BCL2 genes during sleep deprivation and acute anaerobic exercise. Participants included 20 healthy men age 26–35 years, randomized into the L-arginine intervention group (n = 10) and a placebo control (n = 10). The running-based anaerobic sprint test (RAST) was used for anaerobic exercise. Intervention subjects took one 1000 mg L-arginine tablet daily for 8 weeks. The Real-Time PCR method was used to determine apoptosis gene expression in peripheral blood mononuclear cells (PBMCs). Acute anaerobic exercise and sleep deprivation both increased the expression of BAX and CCAR2 genes, and decreased the expression of BCL2 and BMAL1 genes (p < 0.05 for all). L-arginine supplementation increased the expression of BMAL1 and BCL2 genes and decreased the expression of BAX and CCAR2 genes relative to control (p < 0.05). L-Arginine controlled the increase in expression of BAX and CCAR2 genes and the decrease in expression of BCL2 and BMAL1 genes in response to sleep deprivation and acute anaerobic exercise (p < 0.05). Our results showed that 24-hour sleep deprivation and acute anaerobic exercise increased the expression of pro-apoptotic genes (BAX and CCAR2) and decreased the expression of anti-apoptotic genes (BCL2 and BMAL1), although the effect of sleep deprivation is greater. In this situation, L-arginine supplementation may balance the apoptotic state of peripheral blood mononuclear cells. However, any recommendation about this needs further research.

The Effects of Body Positions and Abduction Angles on Shoulder Muscle Activity Patterns during External Rotation Exercises.

Excess and repetitive glenohumeral external rotation (ER) is at a higher risk for shoulder injuries, which occurs frequently in professional sports and specific occupations. Current rehabilitation programs emphasize selective targeting of muscle activity, which can help restore dysfunctional muscle imbalances or prevent injuries. However, the impact of different body postures on GH muscle activity during ER exercises has not been fully understood. Therefore, the purpose of this study was to investigate shoulder EMG activity for different body positions and humeral abduction angles during ER exercises. Twenty-three healthy young men (age: 22.3 ± 2.3, height: 175.75 ± 4.02, mass: 75.37 ± 9.14) participated in this study. Surface Electromyography was recorded from seven shoulder muscles: upper trapezius, lower trapezius, serratus anterior, infraspinatus, and deltoid. Six ER exercises: three postures (sitting, supine lying, and prone lying) and two abduction angles (ABD; 45° and 90°) were tested using an isokinetic dynamometer. During a sitting position, the lower trapezius/upper trapezius muscle activity ratios were significantly increased for sitting compared to supine lying and prone lying (p < 0.001, p = 0.004). Serratus anterior/upper trapezius co-contraction indices were significantly increased for 90° than 45° ABD (p < 0.001). These findings can provide insight into new training programs aimed at restoring GH muscle imbalances.

Immunohistochemical basing of the pathogenesis equality of varicose vein transformation in varicocele and varicose veins of the lower extremities

Background. Varicocele as well as varicose veins of the lower extremities are quite widespread. To date, the mechanisms of variceal transformation remain not completely clear.Aim. To study the immunohistochemical profile in order to substantiate the common pathogenesis of varicose veins transformation in varicocele and varicose veins of the lower limbs; to confirm the key role of undifferentiated connective tissue dysplasia syndrome in the development of these diseases.Materials and methods. Vein wall fragments from 24 male patients aged 6–35 years old divided into the corresponding groups: group 1–12 patients with varicocele, group 2–12 patients with varicose veins of the lower limbs. Control group – 5 practically healthy men (age 16–32 years). Immunohistochemical study was performed with monoclonal antibodies to collagen types III, IV, α-SMA, fibronectin, laminin, MMP-2 and MMP-9, TGF-β1.Results and discussion. Histological and immunohistochemical studies of vein wall biopsy specimens in both groups revealed similar morphological changes, different from the control group. When assessing the expression level of α-SMA in both study groups, there was marked expression in the bundles of hypertrophic smooth muscle cells (in the zone of wall thickening where fibrosis was minimal) and weak expression in the bundles of smooth muscle cells “enmeshed” in connective tissue sleeves. Collagen type III showed weak expression in the subintimal zone and between the bundles of superficially located smooth muscle cells in both study groups. Expression of type IV collagen was detected in the areas of wall thickening and hypertrophy of smooth muscle cells. In both groups there was a pronounced expression of fibronectin in the most altered sections of the vein walls, especially in the middle layer, around the bundles of smooth muscle cells. There was marked expression of MMP-2 in all layers of the wall, and overexpression of MMP-9 in the areas of wall thinning (in the subintimal zone and muscular layer). TGF-β1 overexpression was also detected in vein biopsy specimens from both groups, predominantly in areas of thinning and pronounced intermuscular fibrosis.Conclusion. Taking into account the similarity of immunohistochemical manifestations in the vein walls in varicocele and varicose veins of the lower limbs we can speak about the common morphogenetic mechanisms of their remodeling. Thus, we consider it possible to combine various forms of varicosity into a single disease – varicose vein disease.

Attenuated pulsatile transition to the cerebral vasculature during high-intensity interval exercise in young healthy men.

What is the central question of this study? High-intensity interval exercise (HIIE) is recommended for its favourable haemodynamic stimulation, but excessive haemodynamic fluctuations may stress the brain: is the cerebral vasculature protected against exaggerated systemic blood flow fluctuation during HIIE? What is the main finding and its importance? Time- and frequency-domain indices of aortic-cerebral pulsatile transition were lowered during HIIE. The findings suggest that the arterial system to the cerebral vasculature may attenuate pulsatile transition during HIIE as a defence mechanism against pulsatile fluctuation for the cerebral vasculature. High-intensity interval exercise (HIIE) is recommended because it provides favourable haemodynamic stimulation, but excessive haemodynamic fluctuations may be an adverse impact on the brain. We tested whether the cerebral vasculature is protected against systemic blood flow fluctuation during HIIE. Fourteen healthy men (age 24 ± 2 years) underwent four 4-min exercises at 80-90% of maximal workload (Wmax ) interspaced by 3-min active rest at 50-60% Wmax . Transcranial Doppler measured middle cerebral artery blood velocity (CBV). Systemic haemodynamics (Modelflow) and aortic pressure (AoP, general transfer function) were estimated from an invasively recorded brachial arterial pressure waveform. Using transfer function analysis, gain and phase between AoP and CBV (0.39-10.0Hz) were calculated. Stroke volume, aortic pulse pressure and pulsatile CBV increased during exercise (time effect: P<0.0001 for all), but a time-domain index of aortic-cerebral pulsatile transition (pulsatile CBV/pulsatile AoP) decreased throughout the exercise bouts (time effect: P<0.0001). Furthermore, transfer function gain reduced, and phase increased throughout the exercise bouts (time effect: P<0.0001 for both), suggesting the attenuation and delay of pulsatile transition. The cerebral vascular conductance index (mean CBV/mean arterial pressure; time effect: P=0.296), an inverse index of cerebral vascular tone, did not change even though systemic vascular conductance increased during exercise (time effect: P<0.0001). The arterial system to the cerebral vasculature may attenuate pulsatile transition during HIIE as a defence mechanism against pulsatile fluctuation for the cerebral vasculature.

Model-based spectral causality of cardiovascular variability interactions during head-down tilt

Objective. Cardiovascular control mechanisms are commonly studied during baroreceptor unloading induced by head-up tilt. Conversely, the effect of a baroreceptor loading induced by head-down tilt (HDT) is less studied especially when the stimulus is of moderate intensity and using model-based spectral causality markers. Thus, this study computes model-based causality markers in the frequency domain derived via causal squared coherence and Geweke spectral causality approach from heart period (HP) and systolic arterial pressure (SAP) variability series. Approach. We recorded HP and SAP variability series in 12 healthy men (age: from 41 to 71 yrs, median: 57 yrs) during HDT at −25°. The approaches are compared by considering two different bivariate model structures, namely the autoregressive and dynamic adjustment models. Markers are computed in traditional frequency bands utilized in cardiovascular control analysis, namely the low frequency (LF, from 0.04 to 0.15 Hz) and high frequency (HF, from 0.15 to 0.4 Hz) bands. Main results. We found that: (i) the two spectral causality metrics are deterministically related but spectral causality markers exhibit different discriminative ability; (ii) HDT reduces the involvement of the baroreflex in regulating HP-SAP variability interactions in the LF band, while leaving unmodified the action of mechanical feedforward mechanisms in both LF and HF bands; (iii) this conclusion does not depend on the model structure. Significance. We conclude that HDT can be utilized to reduce the impact of baroreflex and to study the contribution of regulatory mechanisms different from baroreflex to the complexity of cardiovascular control in humans.

Spatial decrease in muscle activation induced by acute passive static stretching: a possible neuromuscular compartmentalization of the gastrocnemius muscle

Recently, spatial adaptation of muscle excitability during sustained muscle voluntary contractions (MVC) up to fatigue has been reported, suggesting a functional muscle compartmentalization. Acute passive stretching (PS) can induce a reduction in surface electromyography (sEMG) amplitude; however, it is not clear whether PS may decrease motor-unit activity heterogeneously, similar to what occurs with fatigue. Therefore, the aim of the study was to evaluate possible heterogeneity in muscle activation following PS intervention in the gastrocnemius muscle. Thirty healthy men (age: 24±2 yrs., stature: 1.78±0.07 m, body mass: 77±6 kg) underwent a 5-min PS intervention (5 x 45s-on/15s-off cycles). Before (PRE), immediately after (POST) and after 5 (POST5) and 10 min (POST10), participants performed MVCs of the plantar-flexor muscles. Spatial muscle activation was recorded by means of high-density sEMG (HD-sEMG) in the gastrocnemius medialis and lateralis of the stretched and of the contralateral, non-stretched limb. The HD-sEMG root mean square (RMS) and its centroid were calculated. During stretching, the fascicle length and pennation angle (ultrasound approach) were measured for the proximal and distal portion of both muscles, together with the perceived level of discomfort (0-10 visual analogue scale). HD-sEMG RMS was reduced in POST, POST5 and POST10 in both gastrocnemius medialis (p&lt;0.05 in all) and lateralis (p&lt;0.05 in all) of the stretched limb, while the centroid shifted toward a more caudal direction (p&lt;0.05). Interestingly, the same behaviour was found in the contralateral limb in POST for both muscles (both p&lt;0.05). No differences were found in control. During stretching, no differences were found in fascicle length and pennation angle between the proximal and distal portion, whereas a higher discomfort was perceived in the distal portion of both muscles (p&lt;0.05 in all). The uneven spatial decrease in muscle activation following acute PS suggests differences in neuromuscular organization of the gastrocnemius muscle. Possibly, a different discomfort perception between the proximal and distal portion could have induced a different inhibitory effect. The study was funded by a grant of the Universitnà degli Studi di Milano This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Determination of serum zinc concentration in normal healthy men &amp; type II diabetes mellitus patients.

Body zinc content is regulated by the homeostatic mechanism, which regulate zinc absorption and excretion depending on its body requirements. The function of cells and tissues enzymes is depend zinc content &amp; over 70 human body enzymes with which zinc is associated. Pervious studies show that some trace elements like magnesium, zinc, manganese &amp; selenium may play important role in action of insulin hormone, including activation of insulin receptor sites. The aim of the study is to determine the serum level of zinc in normal healthy men &amp; diabetes mellitus type II patients. A cross sectional study was done in Tikrit teaching hospital from beginning of January to end of December 2010. The study conducted on 50 type 2 diabetic male patients was participated in the study. While, 30 normal healthy men age matched (aged 55 to 60 years) were included as a control. Serum zinc was measured for control healthy non diabetic subjects &amp; diabetic type 2 patients. There were non significant differences regarding age. However there is significant increase in BMI of diabetic patients as compare with control men. Fasting serum glucose was significantly higher in DM patients as compare with control subjects. Moreover, there is significant reduction in serum zinc in diabetic patients (89.35 ± 19.23 µg/dl) as compare with normal health subjects (135 ± 35.18 µg/dl). In diabetic patients, there is significant negative correlation between fasting blood sugar &amp; serum zinc (r= - 0.37). In present study conclude that there is a significant reduction in serum zinc in diabetic patients. The present study recommend that diabetic type II patients should be encourage to eat diet rich in zinc or take zinc supplement.

A big data-based prediction model for prostate cancer incidence in Japanese men

To define a normal range for PSA values (ng/mL) by age and create a prediction model for prostate cancer incidence. We conducted a retrospective analysis using 263,073 observations of PSA values in Japanese men aged 18–98 years (2007–2017), including healthy men and those diagnosed with prostate cancer. Percentiles for 262,639 PSA observations in healthy men aged 18–70 years were calculated and plotted to elucidate the normal fluctuation range for PSA values by age. Univariable and multivariable logistic regression analyses were performed to develop a predictive model for prostate cancer incidence. PSA levels and PSA velocity increased with age in healthy men. However, there was no difference in PSA velocity with age in men diagnosed with prostate cancer. Logistic regression analysis showed an increased risk of prostate cancer for PSA slopes ranging from 0.5 to 3.5 ng/mL/year. This study provides age-specific normal fluctuation ranges for PSA levels in men aged 18–75 years and presents a novel and personalized prediction model for prostate cancer incidence. We found that PSA slope values of > 3.5 ng/mL/year may indicate a rapid increase in PSA levels caused by pathological condition such as inflammation but are unlikely to indicate cancer risk.

The Effects of Medium-Term Intake of Hydrogen-Rich Water on Sperm Quality Biomarkers in Normospermic and Oligospermic Men: A Randomized Controlled Pilot Trial

The main aim of this randomized controlled pilot trial was to evaluate the effects of hydrogen-rich water on spermiogram parameters in normospermic and oligospermic men. As many as 12 healthy young men (age 29.1 ± 5.9 years; n = 6 normospermic; n = 6 oligospermic) volunteered. Participants were allocated in a double-blind manner to receive 1 L of hydrogen-rich water per day or 1 L of tap water fortified with magnesium for 8 weeks. Following hydrogen-rich water supplementation, sperm concentration and morphology tended to increase by 12.4 million per milliliter (95% CI; –31.8 to 56.6), and live cells increased by 3.8% (95% CI; –12.5 to 20.1), respectively (P ≤ 0.30). A significant difference between the two interventions was found in sperm vitality (P = 0.03), with hydrogen-rich water being superior to the placebo in terms of an increase in the number of live sperm cells. Subgroup analyses revealed no significant differences between interventions in sperm viability outcomes in oligospermic men (P &gt; 0.05). However, sperm count increased by over 20 million in two of the three oligospermic men (66.7%) receiving hydrogen-rich water, while no oligospermic men in the placebo group increased sperm concentration to euspermic levels (P &lt; 0.01). These preliminary findings suggest hydrogen-rich water is an effective intervention for improving some aspects of male subfertility; further large-sample trials are warranted to corroborate our results.

Changes of the cardiac baroreflex bandwidth during postural challenges.

Baroreflex is commonly typified from heart period (HP) and systolic arterial pressure (SAP) spontaneous variations in the frequency domain mainly by estimating its sensitivity. However, an informative parameter linked to the rapidity of the HP response to SAP changes, such as the baroreflex bandwidth, remains unquantified. We propose a model-based parametric approach for estimating the baroreflex bandwidth from the impulse response function (IRF) of the HP-SAP transfer function (TF). The approach accounts explicitly for the action of mechanisms modifying HP regardless of SAP changes. The method was tested during graded baroreceptor unloading induced by head-up tilt (HUT) at 15°, 30°, 45°, 60°, and 75° (T15, T30, T45, T60, and T75) in 17 healthy individuals (age: 21-36 yr; 9 females and 8 males) and during baroreceptor loading obtained via head-down tilt (HDT) at -25° in 13 healthy men (age: 41-71 yr). The bandwidth was estimated as the decay constant of the monoexponential IRF fitting. The method was robust because the monoexponential fitting described adequately the HP dynamics following an impulse of SAP. We observed that 1) baroreflex bandwidth is reduced during graded HUT and this narrowing is accompanied by the reduction of the bandwidth of mechanisms that modify HP regardless of SAP changes and 2) baroreflex bandwidth is not affected by HDT but that of SAP-unrelated mechanisms becomes wider. This study provides a method for estimating a baroreflex feature that provides different information compared with the more usual baroreflex sensitivity while accounting explicitly for the action of mechanisms changing HP irrespective of SAP.

Added Inspiratory Resistance Does Not Impair Cognitive Function and Mood State.

This study evaluated cognitive function and mood state with inspiratory resistance before and after maximal exercise in hypoxia. Nine healthy men (age = 25 ± 2 years) performed the Automated Neuropsychological Assessment Metrics-4th Edition (ANAM4) of the Stroop color-word test (SCWT) and total mood disturbance (TMD) before and after an incremental cycling exercise until volitional fatigue with four different inspiratory resistances (0, 1.5, 4.5, 7.5 cm H2O·L-1·s-1). There was no significant difference in the interference score of SCWT and TMD at normobaric, hypoxic conditions at four different inspiratory resistances. However, the interference score of SCWT was improved following maximal cycling exercise, whereas TMD was not improved. Inspiratory resistance did not have a deleterious effect on cognitive function and mood state in normobaric hypoxia after maximal cycling exercise. However, following maximal cycling exercise, cognitive function was improved.

PAX7 and MyoD Proteins Expression in Response to Eccentric and Concentric Resistance Exercise in Active Young Men.

Satellite cells play an important role in muscle regeneration, which this process can be affected by different genes including PAX7 and MyoD. Exercise training known as an important strategy for mediating the satellite cell's function. Therefore, the main purpose of the present study is to investigate the changes in PAX7 and MyoD protein expression in response to eccentric and concentric resistance exercise in healthy young men. In this semi-experimental and cross-sectional study, 10 healthy men (age range 18-30 years old) participated. They were randomly divided into two equal groups (n=5) to perform one of two high-intensity eccentric or concentric knee extensions muscle contraction protocols. The contractions included a maximum of 12 sets of 10 repetitions, with a 30 second rest time interval between sets. PAX7 and MyoD protein expression was assessed using Immunohistochemistry analysis from the Vastus Lateralis muscle needle biopsy samples that have been taken 24 hours before and 3 to 4 hours after the end of the exercise protocol. We observed that the PAX7 protein expression level increased significantly after eccentric (47.75%) and concentric (39.21%) (P=0.01) intervention. While, the MyoD protein expression level reduced (38.14%) significantly following acute eccentric resistance exercise (P=0.01). It seems that eccentric or concentric muscular contraction modulates the expression of PAX7 and MyoD protein expression in the skeletal muscle, with further effects observed in eccentric resistance exercise.

Distal overactivation of gastrocnemius medialis in persistent plantarflexion weakness following Achilles tendon repair

Structural alterations of the triceps surae and Achilles tendon (AT) can promote plantarflexion weakness one-year following an AT repair, influencing the activation strategies of the Gastrocnemius Medialis (GM) muscle. However, this is yet to be demonstrated. We aimed to determine whether patients with plantar flexion weakness one-year after AT repair show altered GM spatial activation. In this cross-sectional and case-control study, ten middle-aged men (age 34 ± 7 years old, and 12.9 ± 1.1 months post-surgery) with a high AT total rupture score who attended conventional physiotherapy for six months after surgery, and ten healthy control men (age 28 ± 9 years old), performed maximal and submaximal (40, 60 and 90%) voluntary isometric plantarflexion contractions on a dynamometer. The peak plantar flexor torque was determined by isokinetic dynamometry and the GM neuromuscular activation was measured with a linear surface-electromyography (EMG) array. Overall EMG activation (averaged channels) increased when the muscle contraction levels increased for both groups. EMG spatial analysis in AT repaired group showed an increased activation located distally at 85–99%, 75–97%, and 79–97% of the electrode array length for 40%, 60%, and 90% of the maximal voluntary isometric contractions, respectively. In conclusion, patients with persistent plantar flexion weakness after AT rupture showed higher distal overactivation in GM.

The Skeletal Muscle Transcriptome Profile of Elderly Men with Metabolic Syndrome Based on Weighted Gene Co-Expression Network Analysis

Introduction: This study aimed to understand the transcriptome characteristics of the skeletal muscle of elderly (EL) men with metabolic syndrome (MS) and to find the hub genes and insight into the molecular mechanisms of skeletal muscle in the occurrence and development of MS. Methods: In this study, the limma package of R software was used to analyze the differentially expressed genes in the skeletal muscle of healthy young (YO) adult men, healthy EL men, and EL men diagnosed with MS (SX) for at least 10 years. Bioinformatics methods, such as GO enrichment analysis, KEGG enrichment analysis, and gene interaction network analysis, were used to explore the biological functions of differentially expressed genes, and weighted gene coexpression network analysis (WGCNA) was used to cluster differentially expressed genes into modules. Results: Among the YO group, EL group, and SX group, 65 co-differentially expressed genes were found maybe regulated by age factor and MS factor. Those co-differentially expressed genes were enriched into 25 biological process terms and 3 KEGG pathways. Based on the WGCNA results, a total of five modules were identified. Fifteen hub genes may play an essential role in regulating the function of skeletal muscle of EL men with MS. Conclusions: 65 differentially expressed genes and 5 modules may regulate the function of skeletal muscle of EL men with MS, among which fifteen hub genes may play an essential role in the occurrence and development of MS.