Publications by authors named "Antonia Kaltsatou"

20 Publications

  • Page 1 of 1

Effects of exercise-heat stress on circulating stress hormones and interleukin-6 in young and older men.

Temperature (Austin) 2020 24;7(4):389-393. Epub 2020 May 24.

Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.

Aging is associated with impairments in thermoregulatory function, which may augment the neuroendocrine and immune response in older relative to young adults during physical activity in the heat. This study was therefore aimed at examining changes in circulating endocrine hormones as cortisol (COR), prolactin (PRL), human growth hormone (hGH) and interleukin-6 (IL-6) in young and older men prior to and following an incremental, exercise-heat stress protocol (40°C and ~15% relative humidity). Accordingly, ten habitually active young (mean±SD; 21 ± 1 years) and ten older (65 ± 3 years) men performed three 30-min bouts of cycling at increasing metabolic heat productions (300, 400 and 500 W, equal to light, moderate and vigorous exercise), each separated by a 15-min recovery. Consistent with our hypothesis, we observed augmented IL-6 in older (3.55 ± 1.62 pg/mL) compared to young men (1.59 ± 0.88 pg/mL) following the protocol (p < 0.001). However, no significant between-group differences were observed for COR and hGH (all p > 0.050). We show that when assessed following incremental exercise in the heat, older men display augmented interleukin-6, but similar levels of stress hormones relative to young men.
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http://dx.doi.org/10.1080/23328940.2020.1768032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7678928PMC
May 2020

Heart rate variability in older workers during work under the Threshold Limit Values for heat exposure.

Am J Ind Med 2020 09 16;63(9):787-795. Epub 2020 Jul 16.

Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Canada.

Background: The Threshold Limit Values (TLV) of the American Conference of Governmental and Industrial Hygienists indicate the levels of heat stress that all workers may be repeatedly exposed to without adverse health effects. In this study, we evaluated heart rate variability (HRV) during moderate-to-heavy work performed continuously or according to different TLV work-rest (WR) allocations in healthy physically active older workers.

Methods: Nine healthy older (58 ± 5 years) males performed three different 120-minute conditions in accordance with TLV guidelines for moderate-to-heavy intensity work (360 W fixed rate of heat production) in different wet-bulb globe temperatures (WBGT): continuous cycling at 28°C WBGT (CON), as well as intermitted work performed at WR of 3:1 in 29°C WBGT (WR3:1), and at WR of 1:1 at 30°C (WR1:1). Rectal temperature and HRV (3-lead electrocardiogram [ECG]) were assessed throughout.

Results: Coefficient of Variation, Poincaré SD2, and Shannon Entropy were decreased during the CON compared with the WR3:1 when core temperature exceeded 38°C and after 1 hour of continuous work (P < .05). Also, 4 of the 12 HRV indices studied were reduced at CON compared with WR1:1 after 2 hours of accumulated work time (P < .05). Participants worked longer before core temperature reached 38°C during the WR1:1 and the WR3:1, compared with CON (P < .05).

Conclusions: Incorporating breaks during moderate-to-heavy work in the heat for older adults can reduce autonomic stress and prolong the work performed at safe core temperature levels. The TLV WR1:1 provides increased cardiac protection for older workers, as compared with the CON and the WR3:1.
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http://dx.doi.org/10.1002/ajim.23156DOI Listing
September 2020

Age differences in cardiac autonomic regulation during intermittent exercise in the heat.

Eur J Appl Physiol 2020 Feb 1;120(2):453-465. Epub 2020 Jan 1.

Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, 125 University Private, Room 367, Montpetit Hall, Ottawa, ON, K1N 6N5, Canada.

Purpose: This study aimed to detect potential differences in heart-rate variability (HRV) during a moderate-intensity intermittent exercise in the heat among physically active young (25.8 ± 1.9 years), middle-aged (43.5 ± 2.8 years), and older (62.9 ± 3.7 years) men.

Methods: Thirty-three participants (11/group) performed four successive bouts of 15-min cycling at a moderate fixed rate of metabolic heat production of ~ 400 W; each separated by a 15-min recovery with 1 h of final recovery in a hot and dry environment (35 °C, 20% relative humidity). Twelve HRV indices were computed that have been commonly described in the literature, and characterized various domains of the variability and complexity of heart rate.

Results: Cardiac autonomic regulation during intermittent exercise in the heat, as well as during pre-exercise rest and recovery was significantly affected by age, as changes were observed among the three different aged groups in five indices (p ≤ 0.05). Similarly, time influenced cardiac autonomic regulation as three indices showed changes across time (p ≤ 0.05) during intermittent exercise, whilst five indices displayed significant changes (p ≤ 0.05) during rest and recovery in the heat.

Conclusions: This study supports that moderate-intensity intermittent exercise in the heat is associated with significant cardiac autonomic dysregulation in older men, as compared to young and middle-aged men, yet it highlights the importance of developing preventative health strategies for heat-related illness in aged individuals.
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http://dx.doi.org/10.1007/s00421-019-04290-8DOI Listing
February 2020

Cardiac autonomic function during intradialytic exercise training.

Postgrad Med 2019 Sep 15;131(7):539-545. Epub 2019 Sep 15.

Department of Physical Education & Sport Science, University of Thessaly , Trikala , Greece.

: Cardiac autonomic nervous system (ANS) dysfunction is a common feature in patients receiving hemodialysis (HD) therapy, whilst is associated with an increased risk of ventricular arrhythmias and sudden cardiac death. The aim of this study is to investigate and compare the hemodynamic changes and responses of ANS function in HD patients using pupillometry and Heart Rate Variability (HRV) parameters. : Sixteen chronic kidney diseases (CKD) patients receiving HD (52.18 ± 17.7 years) underwent both pupillometric measurements using a portable handheld pupil-measuring device and standard HRV analysis pre HD, every hour and 30 min post-HD session under two different scenarios: at rest while the patient resting at HD bed and when the patient performed a single bout of intradialytic aerobic exercise lasting for 45 min during the second hour of the HD therapy. : No significant changes in ANS values were observed in neither of the pupillometric and the HRV values pre HD, for each hour and post-HD session. HRV parameters were significantly correlated with pupillometric parameters at pre HD and immediately after the single bout of intradialytic exercise. ANS activity did not differ during the conventional HD session and during the session included intradialytic exercise. Moreover, sympatho-vagal balance indices deriving from pupillometric assessment showed beneficial changes after the exercise event. : Pupillometry is a promising and robust technique with fewer artifacts compared to HRV especially in studies involving exercise sessions. Thus, pupillometry can be used as a complementary tool in the evaluation of cardiac autonomic dysfunction.
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http://dx.doi.org/10.1080/00325481.2019.1663707DOI Listing
September 2019

Effect of Cocoa Products and Its Polyphenolic Constituents on Exercise Performance and Exercise-Induced Muscle Damage and Inflammation: A Review of Clinical Trials.

Nutrients 2019 06 28;11(7). Epub 2019 Jun 28.

Department for Quality of Life Studies, University of Bologna, Bologna 40126, Italy.

In recent years, the consumption of chocolate and, in particular, dark chocolate has been "rehabilitated" due to its high content of cocoa antioxidant polyphenols. Although it is recognized that regular exercise improves energy metabolism and muscle performance, excessive or unaccustomed exercise may induce cell damage and impair muscle function by triggering oxidative stress and tissue inflammation. The aim of this review was to revise the available data from literature on the effects of cocoa polyphenols on exercise-associated tissue damage and impairment of exercise performance. To this aim, PubMed and Web of Science databases were searched with the following keywords: "intervention studies", "cocoa polyphenols", "exercise training", "inflammation", "oxidative stress", and "exercise performance". We selected thirteen randomized clinical trials on cocoa ingestion that involved a total of 200 well-trained athletes. The retrieved data indicate that acute, sub-chronic, and chronic cocoa polyphenol intake may reduce exercise-induced oxidative stress but not inflammation, while mixed results are observed in terms of exercise performance and recovery. The interpretation of available results on the anti-oxidative and anti-inflammatory activities of cocoa polyphenols remains questionable, likely due to the variety of physiological networks involved. Further experimental studies are mandatory to clarify the role of cocoa polyphenol supplementation in exercise-mediated inflammation.
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http://dx.doi.org/10.3390/nu11071471DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683266PMC
June 2019

Evidence of Blood and Muscle Redox Status Imbalance in Experimentally Induced Renal Insufficiency in a Rabbit Model.

Oxid Med Cell Longev 2019 4;2019:8219283. Epub 2019 Apr 4.

Muscle Physiology & Mechanics Group, CREHP, DPESS, University of Thessaly, Trikala 42100, Greece.

Chronic kidney disease (CKD) is accompanied by a disturbed redox homeostasis, especially in end-stage patients, which is associated with pathological complications such as anemia, atherosclerosis, and muscle atrophy. However, limited evidence exists about redox disturbances before the end stage of CKD. Moreover, the available redox literature has not yet provided clear associations between circulating and tissue-specific (muscle) oxidative stress levels. The aim of the study was to evaluate commonly used redox status indices in the blood and in two different types of skeletal muscle (psoas, soleus) in the predialysis stages of CKD, using an animal model of renal insufficiency, and to investigate whether blood redox status indices could be reflecting the skeletal muscle redox status. Indices evaluated included reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), catalase (CAT), total antioxidant capacity (TAC), protein carbonyls (PC), and thiobarbituric acid reactive substances (TBARS). Results showed that blood GSH was higher in the uremic group compared to the control (17.50 ± 1.73 vs. 12.43 ± 1.01, = 0.033). In both muscle types, PC levels were higher in the uremic group compared to the control (psoas: 1.086 ± 0.294 vs. 0.596 ± 0.372, soleus: 2.52 ± 0.29 vs. 0.929 ± 0.41, < 0.05). The soleus had higher levels of TBARS, PC, GSH, CAT, and GR and lower TAC compared to the psoas in both groups. No significant correlations in redox status indices between the blood and skeletal muscles were found. However, in the uremic group, significant correlations between the psoas and soleus muscles in PC, GSSG, and CAT levels emerged, not present in the control. Even in the early stages of CKD, a disturbance in redox homeostasis was observed, which seemed to be muscle type-specific, while blood levels of redox indices did not seem to reflect the intramuscular condition. The above results highlight the need for further research in order to identify the key mechanisms driving the onset and progression of oxidative stress and its detrimental effects on CKD patients.
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http://dx.doi.org/10.1155/2019/8219283DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6476063PMC
December 2019

Impact of pre-cooling therapy on the physical performance and functional capacity of multiple sclerosis patients: A systematic review.

Mult Scler Relat Disord 2019 Jan 13;27:419-423. Epub 2018 Nov 13.

FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Karies 42100, Greece. Electronic address:

Patients with multiple sclerosis experience many complications that gradually lead them to comorbidity and disability. Exercise could prevent and ameliorate the symptoms that comorbidity or inactivity generate. However, until recently it was suggested that multiple sclerosis patients should not participate in exercise training programs because these patients are characterized by thermoregulatory failure and the heat stress due to physical work could exacerbate the disease symptoms. Furthermore, taken into account that 60-80% of the multiple sclerosis patients present adverse clinical symptoms when their body temperature is increased (not only due to physical working but even when immerse in hot water or by exposure to infrared lamps or to the sun), the need for the development of treatment strategies to overcome the thermoregulatory problem in these patients is crucial. Given that pre-cooling has been proposed as an effective method, the aim of this systematic review is to discuss the current knowledge for the effects of cooling therapy on the functional capacity of multiple sclerosis patients. The relevant literature includes many articles, but only a handful of studies published thus far have used a cooling intervention in multiple sclerosis patients and have examined the effects of pre-cooling on functional capacity. These studies used active cooling methods, namely garments or other material that are cooled by circulating liquid through a tube, as well as passive, cooling methods. Passive cooling methods include passive cooling garments or other material namely garments that have ice or gel packs inside them. Overall, the results of all the studies analysed in this review demonstrated that pre-cooling therapy can prevent the symptom worsening due to increased body temperature in multiple sclerosis patients without causing adverse effects. Therefore, such strategies could serve as a complimentary therapeutic approach in multiple sclerosis patients.
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http://dx.doi.org/10.1016/j.msard.2018.11.013DOI Listing
January 2019

Age alters cardiac autonomic modulations during and following exercise-induced heat stress in females.

Temperature (Austin) 2018 15;5(2):184-196. Epub 2018 Mar 15.

Human and Environmental Physiology Research Unit, University of Ottawa, Ontario, Canada.

The aim of this study was to examine the effect of natural ageing on heart rate variability during and following exercise-induced heat stress in females. Eleven young (∼24 years) and 13 older (∼51 years), habitually active females completed an experimental session consisting of baseline rest, moderate intensity intermittent exercise (four 15-min bouts separated by 15-min recovery) and 1-hour of final recovery in a hot and dry (35°C, 20% relative humidity) environment. Respiratory and heart rate recordings were continuously logged with 10-min periods analysed at the end of: baseline rest; each of the exercise and recovery bouts; and during the 1-hour final recovery period. Comparisons over time during exercise and recovery, and between groups were conducted via two-way repeated-measures ANCOVAs with rest values as the covariate. During baseline rest, older females exhibited lower heart rate variability compared to young females with similar levels of respiration and most (∼71-79%) heart rate variability measures during repeated exercise and recovery. However, older females exhibited heart rate variability metrics suggestive of greater parasympathetic modulation (greater long axis of Poincare plot, cardiac vagal index; lower low-high frequency ratio) during repeated exercise with lower indices during the latter stage of prolonged recovery (less very low frequency component, Largest Lyapunov Exponent; greater cardiac sympathetic index). The current study documented several unique, age-dependent differences in heart rate variability, independent of respiration, during and following exercise-induced heat stress for females that may assist in the detection of normal heat-induced adaptations as well as individuals vulnerable to heat stress.
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http://dx.doi.org/10.1080/23328940.2018.1432918DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6204987PMC
March 2018

Management of Blood Pressure and Heart Rate in Chronic Kidney Disease.

Curr Pharm Des 2017 ;23(31):4603-4608

School of Physical Education & Sport Science, University of Thessaly, Karies, 42100, Trikala, Greece.

Background: Hypertension is considered a major health problem in patients with chronic kidney disease (CKD) as approximately 80-85% of CKD patients' suffer from hypertension in the United States. Hypertension is the second leading cause of CKD after diabetes and is strongly related to morbidity and mortality. It has been found that there is a relation among hypertension, glomerular filtration rate (GFR) and creatinine levels.

Objective: Since there is a strong relation between hypertension and CKD, and hypertension seems to lead to cardiovascular diseases, which have epidemic proportions in CKD, this review article discusses the etiology of hypertension and the existing optimal therapies that contribute to the hypertension and heart rate management.

Results: There are many approaches that contribute to the management of hypertension and heart rate in CKD patients. Lifestyle modifications in combination with drug therapy lead to the better control of hypertension in CKD patients.

Conclusion: Hypertension is strongly related to cardiovascular diseases in CKD patients. Since this relation exists and hypertension leads to cardiovascular diseases, the management of hypertension and increased heart rate should be a main therapeutic target in these patients.
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http://dx.doi.org/10.2174/1381612823666170829164305DOI Listing
July 2018

Impact of Flavonols on Cardiometabolic Biomarkers:  A Meta-Analysis of Randomized Controlled Human  Trials to Explore the Role of Inter-Individual  Variability.

Nutrients 2017 02 9;9(2). Epub 2017 Feb 9.

BET/ITQB, Molecular Nutrition & Health Laboratory, 2780-157 Oeiras, Portugal.

Several  epidemiological  studies  have  linked  flavonols  with  decreased  risk  of  cardiovascular  disease  (CVD).  However,  some  heterogeneity  in  the  individual  physiological  responses to the consumption of these compounds has been identified. This meta-analysis aimed to  study the effect of flavonol supplementation on biomarkers of CVD risk such as, blood lipids, blood  pressure and plasma glucose, as well as factors affecting their inter-individual variability. Data from  18 human randomized controlled trials were pooled and the effect was estimated using fixed or  random effects meta-analysis model and reported as difference in means (DM). Variability in the  response of blood lipids to supplementation with flavonols was assessed by stratifying various  population subgroups: age, sex, country, and health status. Results showed significant reductions  in total cholesterol (DM = -0.10 mmol/L; 95% CI: -0.20, -0.01), LDL cholesterol (DM = -0.14 mmol/L;  Nutrients 2017, 9, 117  2 of 21  95% CI: -0.21, 0.07), and triacylglycerol (DM = -0.10 mmol/L; 95% CI: -0.18, 0.03), and a significant  increase in HDL cholesterol (DM = 0.05 mmol/L; 95% CI: 0.02, 0.07). A significant reduction was also  observed in fasting plasma glucose (DM = -0.18 mmol/L; 95%CI: -0.29, -0.08), and in blood pressure  (SBP: DM = -4.84 mmHg; 95% CI: -5.64, -4.04; DBP: DM = -3.32 mmHg; 95% CI: -4.09, -2.55).  Subgroup analysis showed a more pronounced effect of flavonol intake in participants from Asian  countries and in participants with diagnosed disease or dyslipidemia, compared to healthy and  normal baseline values. In conclusion, flavonol consumption improved biomarkers of CVD risk,  however, country of origin and health status may influence the effect of flavonol intake on blood  lipid levels.
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http://dx.doi.org/10.3390/nu9020117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5331548PMC
February 2017

Systemic Redox Imbalance in Chronic Kidney Disease: A Systematic Review.

Oxid Med Cell Longev 2016 3;2016:8598253. Epub 2016 Aug 3.

Department of Physical Education & Sport Science, University of Thessaly, Karyes, 421 00 Trikala, Greece; Department of Kinesiology, Institute for Research and Technology-CERTH, Thessaly, Karyes, 421 00 Trikala, Greece; Faculty of Sport and Health Sciences, University of St Mark and St John, Plymouth PL6 8BH, UK.

Patients with chronic kidney disease (CKD) experience imbalance between oxygen reactive species (ROS) production and antioxidant defenses leading to cell and tissue damage. However, it remains unclear at which stage of renal insufficiency the redox imbalance becomes more profound. The aim of this systematic review was to provide an update on recent advances in our understanding of how the redox status changes in the progression of renal disease from predialysis stages 1 to 4 to end stage 5 and whether the various treatments and dialysis modalities influence the redox balance. A systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. In total, thirty-nine studies met the inclusion criteria and were reviewed. Even from an early stage, imbalance in redox status is evident and as the kidney function worsens it becomes more profound. Hemodialysis therapy per se seems to negatively influence the redox status by the elevation of lipid peroxidation markers, protein carbonylation, and impairing erythrocyte antioxidant defense. However, other dialysis modalities do not so far appear to confer advantages. Supplementation with antioxidants might assist and should be considered as an early intervention to halt premature atherogenesis development at an early stage of CKD.
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http://dx.doi.org/10.1155/2016/8598253DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4987477PMC
March 2017

Impact of traditional Greek dancing on jumping ability, muscular strength and lower limb endurance in cardiac rehabilitation programmes.

Eur J Cardiovasc Nurs 2017 02 8;16(2):150-156. Epub 2016 Jul 8.

1 Laboratory of Sports Medicine, Aristotle University, Greece.

Aims: The objective of this study was to evaluate the effect of a training programme based on traditional Greek dance on the jumping ability, muscle strength and lower limb endurance in patients with chronic heart failure (CHF).

Patients And Methods: Forty Greek patients with CHF graded as NYHA ⩽ II and aged 73.2±4.7 years were randomly divided into two groups. Group A ( n=20) participated in a three-month physical rehabilitation programme based on Greek traditional dances, whereas group B ( n=20) remained untrained and served as the control group. All patients were studied before and after the 12-week exercise training programme. At baseline and follow-up the exercise capacity of the patients was evaluated by the six-minute walking test, their lower extremity muscle strength was evaluated by an isokinetic dynamometer and their jumping ability by the Myotest-Pro test, which includes three types of jumps (plyometric, countermovement and squat jumps).

Results: No significant difference was observed between the two groups at the baseline evaluation. At follow-up, group A showed significant improvements in walking distance calculated from the six-minute walking test (10.0% improvement; p<0.05), in lower limb strength (10.32% improvement; p<0.05), and in countermovement jump speed (6.9%; p<0.05) and squat jump speed (5.8%; p<0.05). Group A also increased their jump plyometry height by 13.86% ( p<0.05), their counter jump height by 10.68% ( p<0.05) and their squat jump height by 10.45% ( p<0.05). Group A had a 6.85% ( p<0.05) increased force of counter jump compared with group B.

Conclusion: The design and implementation of cardiac rehabilitation programmes using Greek traditional dances in patients with CHF are both safe and effective in improving lower limb function.
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http://dx.doi.org/10.1177/1474515116636980DOI Listing
February 2017

Intra-Renal Hemodynamic Changes After Habitual Physical Activity in Patients with Chronic Kidney Disease.

Curr Pharm Des 2016 ;22(24):3700-14

25, Karditsis, 42100, Trikala, Thessalia, Greece.

Background: Chronic Kidney Disease (CKD) is considered a silent epidemic with a continuously growing prevalence around the world. Due to uremia many functional and morphological abnormalities occur in almost all systems. Mostly affected, the cardiovascular system, leads to diminished cardiac function that affects patients' functional capacity and physical activity levels, reducing survival and increasing all-cause mortality. Systematic exercise training ameliorates uremia induced body deficits and significantly improves the survival of CKD patients. Intradialytic exercise training has been recommended as a complementary therapeutic modality equally important to hemodialysis.

Methods: The aim of this systematic review is to provide an update on recent advances in our understanding of how exercise training improves functionality of the cardiovascular system through the hemodynamic changes induced by habitual or intradialytic and/or home-based exercise training programs.

Results: Systematic exercise training induces beneficial adaptive responses and influences many sensitive physiological biomarkers, such as oxidative stress biomarkers that are implicated in the development of atherosclerosis. Additionally, exercise training decreases the cardiovascular risk by improving the autonomic nervous system activity and the left ventricular function and by reducing nontraditional risk factors such as epicardial adipose tissue. It seems that all these central and peripheral adaptations to exercise training significantly contribute to improvements in functional capacity and exercise tolerance among CKD patients and result in the risk reduction of CKD-associated disorders.

Conclusion: Exercise training could serve as a complimentary therapeutic strategy in CKD patients while health care providers should motivate patients to engage in any type of exercise training programs.
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http://dx.doi.org/10.2174/1381612822666160322144936DOI Listing
January 2018

Cognitive impairment as a central cholinergic deficit in patients with Myasthenia Gravis.

BBA Clin 2015 Jun 23;3:299-303. Epub 2015 Apr 23.

Neurology Clinic of AHEPA Hospital, Neuroscience Division, Medicine School, Aristotle University of Thessaloniki, Greece.

Background: The purpose of this study was to investigate with neurophysiological and neuropsychological methods such as pupillometry, cognitive test and Hamilton Depression Rating Scale (HAM-D) the hypothesis of Central Nervous System (CNS) cholinergic involvement in patients with Myasthenia Gravis (MG).

Methods: Thirty-two patients (32) with MG and a mean age of 51.1 ± 17.2 volunteered to participate in this investigation, while thirty-three (33) healthy subjects with a mean age of 50.2 ± 14.8 served as controls. All subjects underwent pupillometric measurements and performed the Wechsler Memory Scale (WMS) and HAM-D. The pupillometric indices studied were: 1) latency for the onset of constriction (T1), 2) maximum constriction velocity (VCmax) and 3) maximum constriction acceleration (ACmax).

Results: T1 was found significantly increased by 21.7% (p < 0.05) in MG patients as compared to healthy subjects. Conversely, VCmax and ACmax were significantly decreased in MG patients by 33.3% (p < 0.05) and 43.5% (p < 0.05) respectively, as opposed to healthy subjects. Additionally, MG patients showed significantly decreased score in WMS by 41.6% (p < 0.05) as compared to healthy controls. No significant difference was found for HAM-D between the two groups.

Conclusions: VCmax and ACmax are governed mainly by the action of the Parasympathetic Nervous System, through acetylcholine. The results of this study demonstrate that the CNS may be affected in MG and support the hypothesis that MG has central cholinergic effects manifested by cognitive dysfunction.
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http://dx.doi.org/10.1016/j.bbacli.2015.04.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4661582PMC
June 2015

Cognitive function and exercise training for chronic renal disease patients: A literature review.

J Bodyw Mov Ther 2015 Jul 18;19(3):509-15. Epub 2015 Apr 18.

Department of PE and Sport Science, University of Thessaly, Trikala, Greece; Department of Medicine, Division of Nephrology, University of Thessaly, Greece.

Objective: Cognitive impairment is very often noted in patients with Chronic Kidney Disease (CKD). Even though, exercise is considered to be a quantifiable activity that improves cognition in animals and humans, it seems that few studies have examined the relationship between cognitive function and CKD from the perspective of physical activity and cognitive performance. Thus, this evidence based review summarizes the present level of knowledge regarding the effects of exercise training on cognitive function in CKD patients.

Data Sources: A comprehensive literature search was conducted in PubMed and Scopus from May 2014 through June 2014, by using the Cochrane and PRISMA guidelines.

Review Methods: Eligibility of the studies based on titles, abstracts and full-text articles was determined by two reviewers. Studies were selected using inclusion and exclusion criteria. We included only those studies that: assessed cognitive function in humans and animals using validated neuropsychological methods in chronic renal diseases patients; used exercise training protocols; addressed randomized control trials or controlled trials or clinical trials designed to evaluate cognitive impairment; and articles that were written in English. Studies were excluded when they concerned behavioral approaches and underpowered studies.

Results: According to the current review only a few studies have examined the issue of cognitive function in CKD patients. These studies indicate that these patients often exhibit cognitive impairment, which is highly associated with poor outcomes. It has been supported that exercise training can induce positive changes in brain metabolism favoring better scores in cognitive function in Chronic Kidney Disease patients although the physiological mechanisms, which explain the influence of physical activity on cognition, have focused on changes in neurotransmitters, neurotrophins and vasculature.

Conclusion: Systematic exercise training seems to improve cognitive function in Chronic Kidney Disease patients but further research is warranted to further clarify the mechanisms involved.
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http://dx.doi.org/10.1016/j.jbmt.2015.04.006DOI Listing
July 2015

Uremic myopathy: is oxidative stress implicated in muscle dysfunction in uremia?

Front Physiol 2015 30;6:102. Epub 2015 Mar 30.

Department of Physical Education and Sport Sciences (DPESS), School of Physical Education (PE), University of Thessaly Trikala, Greece.

Renal failure is accompanied by progressive muscle weakness and premature fatigue, in part linked to hypokinesis and in part to uremic toxicity. These changes are associated with various detrimental biochemical and morphological alterations. All of these pathological parameters are collectively termed uremic myopathy. Various interventions while helpful can't fully remedy the pathological phenotype. Complex mechanisms that stimulate muscle dysfunction in uremia have been proposed, and oxidative stress could be implicated. Skeletal muscles continuously produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) at rest and more so during contraction. The aim of this mini review is to provide an update on recent advances in our understanding of how ROS and RNS generation might contribute to muscle dysfunction in uremia. Thus, a systematic review was conducted searching PubMed and Scopus by using the Cochrane and PRISMA guidelines. While few studies met our criteria their findings are discussed making reference to other available literature data. Oxidative stress can direct muscle cells into a catabolic state and chronic exposure to it leads to wasting. Moreover, redox disturbances can significantly affect force production per se. We conclude that oxidative stress can be in part responsible for some aspects of uremic myopathy. Further research is needed to discern clear mechanisms and to help efforts to counteract muscle weakness and exercise intolerance in uremic patients.
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http://dx.doi.org/10.3389/fphys.2015.00102DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4378187PMC
April 2015

Evaluation of the cholinergic hypothesis in Alzheimer's disease with neuropsychological methods.

Aging Clin Exp Res 2015 Oct 8;27(5):727-33. Epub 2015 Mar 8.

Neuroscience Division, Medicine School, A Neurology Clinic of AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.

Aim: This study aimed at evaluating the cholinergic hypothesis in Alzheimer's disease (AD) patients utilizing the pupillometry method, cognitive tests and Hamilton Depression Rating Scale (HAM-D), as well as to examine whether a correlation between cognitive tests and pupillometry exists.

Methods: Forty-two patients with mean age 69.2 ± 7.0 years and documented AD volunteered to participate in this study, while 33 healthy matched subjects served as controls. All subjects underwent a pupillometric measurement and performed the Wechsler Memory Scale (WMS) and Mini Mental State Examination (MMSE). Also, HAM-D was used to assess the severity of depressive symptoms. The pupillometric parameters studied were (1) latency for the onset of constriction (T1), (2) maximum constriction velocity (VCmax), and (3) maximum constriction acceleration (ACmax).

Results: In AD patients MMSE and WMS score were correlated with ACmax (r = -0.409, p < 0.05 and r = -0.513, p < 0.05, respectively) and VCmax (r = -0.664, p < 0.05 and r = -0.771, p < 0.05), respectively. Moreover, T1 was found to be significantly increased by 23 % (p < 0.05) in AD patients compared to healthy subjects. Conversely, the mean scores of VCmax and ACmax were significantly decreased in AD patients by 46 % (p < 0.05) and by 47 % (p < 0.05), respectively, as compared to healthy subjects. There was no significant difference between the two groups for HAM-D. Additionally, AD patients showed decreased score in WMS by 40 % (p < 0.05) and in MMSE by 28.5 % (p < 0.05) compared to healthy subjects. Of the indices that were studied VCmax and ACmax are governed mainly by the action of the Parasympathetic Nervous System.

Conclusions: The results of this study demonstrated that there is a correlation between cognitive tests and pupillometry in AD patients. Thus, pupillometry could be considered as a sensitive technique for the investigation of cholinergic deficits, which indirectly lead to memory and cognitive disorders in AD patients.
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http://dx.doi.org/10.1007/s40520-015-0321-8DOI Listing
October 2015

Functional and psychosocial effects of either a traditional dancing or a formal exercising training program in patients with chronic heart failure: a comparative randomized controlled study.

Clin Rehabil 2014 Feb 17;28(2):128-38. Epub 2013 Jul 17.

1Laboratory of Sports Medicine, Aristotle University of Thessaloniki, Thermi, Greece.

Objective: To compare the effects of traditional dancing with formal exercise training in terms of functional and cardiovascular benefits and motivation in patients with chronic heart failure.

Design: Randomized controlled trial.

Setting: Sports Medicine Laboratory.

Subjects: Fifty-one Greek male patients aged 67.1±5.5 years with chronic heart failure of New York Heart Association (NYHA) class II-III, participated in an eight-month study.

Interventions: They were randomly assigned to either training with Greek traditional dances (group A, n=18), formal exercise training (group B, n=16) or a sedentary control group (group C, n=17).

Main Measures: At entry and the end of the study all patients underwent cardiopulmonary exercise testing, functional ability assessment and quality of life evaluations. The Intrinsic Motivation Inventory was also used to assess participants' subjective experience.

Results: After training group A showed increased peak oxygen consumption by 33.8% (19.5 vs. 26.1 ml/kg/min, p<0.05) and B by 32.3% (19.5 vs. 25.8 ml/kg/min, p<0.05), maximal treadmill tolerance by 48.5% (p<0.05) and by 46.4% (p<0.05), and a decreased Slope of expired minute ventilation for carbon dioxide output (VE/VCO2) slope by 18% (p<0.05) and 19.5% (p<0.05), respectively. Trained patients revealed significant improvement in the quality of life indices. Intrinsic Motivation Inventory was increased only in group A by 26.2% (3.08 vs. 3.87, p<0.05).

Conclusions: Exercise training in chronic heart failure patients with Greek traditional dances led to functional and cardiovascular benefits similar to formal exercise training and to a higher level of motivation.
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http://dx.doi.org/10.1177/0269215513492988DOI Listing
February 2014

Physical and psychological benefits of a 24-week traditional dance program in breast cancer survivors.

J Bodyw Mov Ther 2011 Apr 13;15(2):162-7. Epub 2010 Apr 13.

Sports Medicine Laboratory, Department of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.

The purpose of the present study was to evaluate the influence of a mixed exercise program, including Greek traditional dances and upper body training, in physical function, strength and psychological condition of breast cancer survivors. Twenty-seven women (N = 27), who had been diagnosed and surgically treated for breast cancer, volunteered to participate in this study. The experimental group consisted of 14 women with mean age 56.6 (4.2) years. They attended supervised Greek traditional dance courses and upper body training (1 h, 3 sessions/week) for 24 weeks. The control group consisted of 13 sedentary women with mean age 57.1 (4.1) years. Blood pressure, heart rate, physical function (6-min walking test), handgrip strength, arm volume and psychological condition (Life Satisfaction Inventory and Beck Depression Inventory) were evaluated before and after the exercise program. The results showed significant increases of 19.9% for physical function, 24.3% for right handgrip strength, 26.1% for left handgrip strength, 36.3% for life satisfaction and also a decrease of 35% for depressive symptoms in the experimental group after the training program. Significant reductions of 9% for left hand and 13.7% for right hand arm volume were also found in the experimental group. Consequently, aerobic exercise with Greek traditional dances and upper body training could be an alternative choice of physical activity for breast cancer survivors, thus promoting benefits in physical function, strength and psychological condition.
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http://dx.doi.org/10.1016/j.jbmt.2010.03.002DOI Listing
April 2011

The use of pupillometry in the assessment of cardiac autonomic function in elite different type trained athletes.

Eur J Appl Physiol 2011 Sep 23;111(9):2079-87. Epub 2011 Jan 23.

Sports Medicine Laboratory, Department of Physical Education and Sport Sciences, Aristotle University of Thessaloniki, Thermi, 57001 Thessaloniki, Greece.

The aim of the present study was to evaluate cardiac autonomic function by pupillometry in male athletes. Fifteen elite endurance- (END) and eleven power-trained (POWER) athletes and fifteen sedentary individuals (CONTROL) were studied. All subjects underwent three pupillometric measurements: at rest, peak exercise testing and recovery phase. The pupillometric indices studied were: baseline pupil radius (R1), minimum pupil radius (R2), maximum constriction velocity (VC(max)), maximum constriction acceleration (AC(max)), amplitude (AMP, R1-R2), constriction ratio (AMP%). During exercise, RR intervals were obtained for each subject with a Polar S810i for time and frequency domain heart rate variability (HRV) analysis. The following parameters of HRV were measured: standard deviation of all NN intervals (SDNN), the mean square successive differences (rMSSD), percent of NN intervals differing >50 ms from the preceding NN (pNN50), low (LF)- and high (HF)- frequency components of the autoregressive power spectrum of the NN intervals and their ratio (LF/HF). At rest and recovery, END showed significantly increased VC(max) and AC(max) compared to POWER and CONTROL. AMP% was significantly greater in END at rest, peak exercise and recovery compared to POWER and CONTROL. END and POWER had significantly greater AMP at rest and recovery compared to CONTROL. Moreover, all HRV indices were significantly increased in END compared to POWER and CONTROL. However, POWER showed significantly increased rMSSD and LF compared to CONTROL. HRV parameters were significantly correlated with pupillometric parameters during exercise. Our results indicated that any kind of exercise training and mainly endurance one affects autonomic regulation of pupillary light reflex.
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http://dx.doi.org/10.1007/s00421-011-1836-0DOI Listing
September 2011