Giorgos Sakkas

Prof. Giorgos Sakkas

University of Thessaly, School of Physical Education, Sport Science and Dietetics
+3
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2003 in Kidney International
Verified
Journal Article
Closed access
KJKirsten L. Johansen
Kirsten L. Johansen
TSTiffany Shubert
Tiffany Shubert
JDJulie Doyle
Julie Doyle
BSBrian Soher
Brian Soher
Giorgos SakkasGiorgos Sakkas
Giorgos Sakkas
JKJane A. Kent-Braun
Jane A. Kent-Braun

1 August 2006 in Journal of the American Society of Nephrology
Verified
Journal Article
Open access
PDF file
KJKirsten L. Johansen
Kirsten L. Johansen
PPPatricia L. Painter
Patricia L. Painter
Giorgos SakkasGiorgos Sakkas
Giorgos Sakkas
PGPatricia Gordon
Patricia Gordon
JDJulie Doyle
Julie Doyle
TSTiffany Shubert
Tiffany Shubert
Patients who are on hemodialysis commonly experience muscle wasting and weakness, which have a negative effect on physical functioning and quality of life. The objective of this study was to determine whether anabolic steroid administration and resistance exercise training induce anabolic effects among patients who receive maintenance hemodialysis. A randomized 2 × 2 factorial trial of anabolic steroid administration and resistance exercise training was conducted in 79 patients who were receiving maintenance hemodialysis at University of California, San Francisco–affiliated dialysis units. Interventions included double-blinded weekly nandrolone decanoate (100 mg for women; 200 mg for men) or placebo injections and lower extremity resistance exercise training for 12 wk during hemodialysis sessions three times per week using ankle weights. Primary outcomes included change in lean body mass (LBM) measured by dual-energy x-ray absorptiometry, quadriceps muscle cross-sectional area measured by magnetic resonance imaging, and knee extensor muscle strength. Secondary outcomes included changes in physical performance, self-reported physical functioning, and physical activity. Sixty-eight patients completed the study. Patients who received nandrolone decanoate increased their LBM by 3.1 ± 2.2 kg (P < 0.0001). Exercise did not result in a significant increase in LBM. Quadriceps muscle cross-sectional area increased in patients who were assigned to exercise (P = 0.01) and to nandrolone (P < 0.0001) in an additive manner. Patients who exercised increased their strength in a training-specific fashion, and exercise was associated with an improvement in self-reported physical functioning (P = 0.04 compared with nonexercising groups). Nandrolone decanoate and resistance exercise produced anabolic effects among patients who were on hemodialysis. Further studies are needed to determine whether these interventions improve survival.

19 May 2021 in Medicina
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Journal Article
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LNLuis C Nacul
Luis C Nacul
FAFrançois Jérôme Authier
François Jérôme Authier
CSCarmen Scheibenbogen
Carmen Scheibenbogen
LLLorenzo Lorusso
Lorenzo Lorusso
IHIngrid Bergliot Helland
Ingrid Bergliot Helland
ELEliana Lacerda
Eliana Lacerda
Designed by a group of ME/CFS researchers and health professionals, the European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (EUROMENE) has received funding from the European Cooperation in Science and Technology (COST)—COST action 15111—from 2016 to 2020. The main goal of the Cost Action was to assess the existing knowledge and experience on health care delivery for people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in European countries, and to enhance coordinated research and health care provision in this field. We report our findings and make recommendations for clinical diagnosis, health services and care for people with ME/CFS in Europe, as prepared by the group of clinicians and researchers from 22 countries and 55 European health professionals and researchers, who have been informed by people with ME/CFS.

11 September 2013 in BMC Nephrology
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Journal Article
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Christoforos GiannakiChristoforos Giannaki
Christoforos Giannaki
Giorgos SakkasGiorgos Sakkas
Giorgos Sakkas
CKChristina Karatzaferi
Christina Karatzaferi
GHGeorgios Hadjigeorgiou
Georgios Hadjigeorgiou
ELEleftherios Lavdas
Eleftherios Lavdas
ISIoannis Stefanidis
Ioannis Stefanidis
Background: Restless Legs Syndrome is very common in hemodialysis patients however there are no comparative studies assessing the effectiveness of a non-pharmacological treatment to a classical treatment on parameters related to syndromes’ severity and quality of life. Methods: In this randomized, partially double blind, placebo controlled trial, thirty two hemodialysis patients with restless legs syndrome were randomly assigned into three groups: 1) the exercise training group (N = 16), 2) the dopamine agonists group (ropinirole 0.25 mg/d) (N = 8) and 3) the placebo group (N = 8). The intervention programs lasted 6 months. Restless Legs Syndrome severity was assessed using the international severity scale, physical performance by a battery of tests, muscle size and composition by computed tomography, body composition by Dual Energy X Ray Absorptiometry, while depression score, sleep quality, daily sleepiness and quality of life were assessed through questionnaires. Results: Exercise training and dopamine agonists were effective in reducing syndrome’s symptoms by 46% (P = 0.009) and 54% (P = 0.001) respectively. Within group changes revealed that both approaches significantly improved quality of life (P < 0.05), however, only the dopamine agonists significantly improved sleep quality (P = 0.009). Within group changes showed a tendency for lean body mass improvements with dopamine agonists, this reached statistical significance only with the exercise training (P = 0.014), which also reduced fat infiltration in muscles (P = 0.044) and improved physical performance (P > 0.05) in various tests. Between group changes detect significant improvements with both exercise and dopamine agonists in depression score (P = 0.003), while only the dopamine agonist treatment was able to significantly improve sleep quality, compared to exercise and placebo (P = 0.016). Conclusions: A 6-month exercise training regime was as effective as a 6-month low dosage dopamine agonist treatment in reducing restless legs syndrome symptoms and improving depression score in uremic patients. Further research is needed in order to show whether a combination treatment could be more beneficial for the amelioration of RLS. Trial registration: NCT00942253

8 August 2013 in Nephrology Dialysis Transplantation
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Journal Article
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Christoforos GiannakiChristoforos Giannaki
Christoforos Giannaki
GHGeorgios M. Hadjigeorgiou
Georgios M. Hadjigeorgiou
CKChristina Karatzaferi
Christina Karatzaferi
MMMaria Maridaki
Maria Maridaki
YKYiannis Koutedakis
Yiannis Koutedakis
Giorgos SakkasGiorgos Sakkas
Giorgos Sakkas
Uraemic restless legs syndrome (RLS) affects a significant proportion of patients receiving haemodialysis (HD) therapy. Exercise training has been shown to improve RLS symptoms in uraemic RLS patients; however, the mechanism of exercise-induced changes in RLS severity is still unknown. The aim of the current randomized controlled exercise trial was to investigate whether the reduction of RLS severity, often seen after training, is due to expected systemic exercise adaptations or it is mainly due to the relief that leg movements confer during exercise training on a cycle ergometer. This is the first randomized controlled exercise study in uraemic RLS patients. Twenty-four RLS HD patients were randomly assigned to two groups: the progressive exercise training group (n = 12) and the control exercise with no resistance group (n = 12). The exercise session in both groups included intradialytic cycling for 45 min at 50 rpm. However, only in the progressive exercise training group was resistance applied, at 60–65% of maximum exercise capacity, which was reassessed every 4 weeks to account for the patients' improvement. The severity of RLS symptoms was evaluated using the IRLSSG severity scale, functional capacity by a battery of tests, while sleep quality, depression levels and daily sleepiness status were assessed via validated questionnaires, before and after the intervention period. All patients completed the exercise programme with no adverse effects. RLS symptom severity declined by 58% (P = 0.003) in the progressive exercise training group, while a no statistically significant decline was observed in the control group (17% change, P = 0.124). Exercise training was also effective in terms of improving functional capacity (P = 0.04), sleep quality (P = 0.038) and depression score (P = 0.000) in HD patients, while no significant changes were observed in the control group. After 6 months of the intervention, RLS severity (P = 0.017), depression score (P = 0.002) and daily sleepiness status (P = 0.05) appeared to be significantly better in the progressive exercise group compared with the control group. A 6-month intradialytic progressive exercise training programme appears to be a safe and effective approach in reducing RLS symptom severity in HD patients. It seems that exercise-induced adaptations to the whole body are mostly responsible for the reduction in RLS severity score, since the exercise with no applied resistance protocol failed to improve the RLS severity status of the patients. NCT00942253.

1 April 2009 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
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KMKathleen Mulligan
Kathleen Mulligan
HKHootan Khatami
Hootan Khatami
JSJean-Marc Schwarz
Jean-Marc Schwarz
Giorgos SakkasGiorgos Sakkas
Giorgos Sakkas
ADAlex M. DePaoli
Alex M. DePaoli
MSMorris Schambelan
Morris Schambelan
Context: Leptin deficiency is associated with dyslipidemia and insulin resistance in animals and humans with lipoatrophy; leptin replacement ameliorates these abnormalities. Objective: The objective of the study was to evaluate the effects of leptin therapy in lipoatrophic HIV-infected patients with dyslipidemia and hypoleptinemia. Design: This was a 6-month, open-label, proof-of-principle pilot study. Setting: Metabolic ward studies were performed before and 3 and 6 months after leptin treatment. Participants: Participants included eight HIV-infected men with lipoatrophy, fasting triglycerides greater than 300 mg/dl, and serum leptin less than 3 ng/ml. Intervention: Recombinant human leptin was given by sc injection (0.01 mg/kg and 0.03 mg/kg twice daily for successive 3 month periods). Outcome Measures: Measures included fat distribution by magnetic resonance imaging and dual-energy X-ray absorptiometry; fasting lipids; insulin sensitivity by euglycemic hyperinsulinemic clamp; endogenous glucose production, gluconeogenesis, glycogenolysis, and whole-body lipolysis by stable isotope tracer studies; oral glucose tolerance testing; liver fat by proton magnetic resonance spectroscopy; and safety. Results: Visceral fat decreased by 32% (P = 0.001) with no changes in peripheral fat. There were significant decreases in fasting total (15%, P = 0.012), direct low-density lipoprotein (20%, P = 0.002), and non-high-density lipoprotein (19%, P = 0.005) cholesterol. High-density lipoprotein cholesterol increased. Triglycerides, whole-body lipolysis, and free fatty acids decreased during fasting and hyperinsulinemia. Fasting insulin decreased. Endogenous glucose production decreased during fasting and hyperinsulinemia, providing evidence of improved hepatic insulin sensitivity. Leptin was well tolerated but decreased lean mass. Conclusions: Leptin treatment was associated with marked improvement in dyslipidemia. Hepatic insulin sensitivity improved and lipolysis decreased. Visceral fat decreased with no exacerbation of peripheral lipoatrophy. Results from this pilot study suggest that leptin warrants further study in patients with HIV-associated lipoatrophy.