Tzortzis Nomikos

Prof. Tzortzis Nomikos

Department of Nutrition & Dietetics, School of Health Science & Education, Harokopio University
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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

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

Representative Publications

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22 June 2023 in Nutrients
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Journal Article
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FBFotios Barkas
Fotios Barkas
EBEirini Bathrellou
Eirini Bathrellou
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
DPDemosthenes Panagiotakos
Demosthenes Panagiotakos
Evangelos LiberopoulosEvangelos Liberopoulos
Evangelos Liberopoulos
Meropi KontogianniMeropi Kontogianni
Meropi Kontogianni
Atherosclerotic cardiovascular disease (ASCVD) remains the major mortality cause in developed countries with hypercholesterolaemia being one of the primary modifiable causes. Lifestyle intervention constitutes the first step in cholesterol management and includes dietary modifications along with the use of functional foods and supplements. Functional foods enriched with plant sterols/stanols have become the most widely used nonprescription cholesterol-lowering approach, despite the lack of randomized trials investigating their long-term safety and cardiovascular efficacy. The cholesterol-lowering effect of plant-sterol supplementation is well-established and a potential beneficial impact on other lipoproteins and glucose homeostasis has been described. Nevertheless, experimental and human observational studies investigating the association of phytosterol supplementation or circulating plant sterols with various markers of atherosclerosis and ASCVD events have demonstrated controversial results. Compelling evidence from recent genetic studies have also linked elevated plasma concentrations of circulating plant sterols with ASCVD presence, thus raising concerns about the safety of phytosterol supplementation. Thus, the aim of this review is to provide up-to-date data on the effect of plant sterols/stanols on lipid-modification and cardiovascular outcomes, as well as to discuss any safety issues and practical concerns.

13 August 2020 in Nutrients
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FBFotios Barkas
Fotios Barkas
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
Evangelos LiberopoulosEvangelos Liberopoulos
Evangelos Liberopoulos
DPDemosthenes Panagiotakos
Demosthenes Panagiotakos
Background: Although a cholesterol-lowering diet and the addition of plant sterols and stanols are suggested for the lipid management of children and adults with familial hypercholesterolemia, there is limited evidence evaluating such interventions in this population. Objectives: To investigate the impact of cholesterol-lowering diet and other dietary interventions on the incidence or mortality of cardiovascular disease and lipid profile of patients with familial hypercholesterolemia. Search methods: Relevant trials were identified by searching US National Library of Medicine National Institutes of Health Metabolism Trials Register and clinicaltrials.gov.gr using the following terms: diet, dietary, plant sterols, stanols, omega-3 fatty acids, fiber and familial hypercholesterolemia. Selection criteria: Randomized controlled trials evaluating the effect of cholesterol-lowering diet or other dietary interventions in children and adults with familial hypercholesterolemia were included. Data collection and analysis: Two authors independently assessed the eligibility of the included trials and their bias risk and extracted the data which was independently verified by other colleagues. Results: A total of 17 trials were finally included, with a total of 376 participants across 8 comparison groups. The included trials had either a low or unclear bias risk for most of the assessed risk parameters. Cardiovascular incidence or mortality were not evaluated in any of the included trials. Among the planned comparisons regarding patients’ lipidemic profile, a significant difference was noticed for the following comparisons and outcomes: omega-3 fatty acids reduced triglycerides (mean difference (MD): −0.27 mmol/L, 95% confidence interval (CI): −0.47 to −0.07, p < 0.01) when compared with placebo. A non-significant trend towards a reduction in subjects’ total cholesterol (MD: −0.34, 95% CI: −0.68 to 0, mmol/L, p = 0.05) and low-density lipoprotein cholesterol (MD: −0.31, 95% CI: −0.61 to 0, mmol/L, p = 0.05) was noticed. In comparison with cholesterol-lowering diet, the additional consumption of plant stanols decreased total cholesterol (MD: −0.62 mmol/L, 95% CI: −1.13 to −0.11, p = 0.02) and low-density lipoprotein cholesterol (MD: −0.58 mmol/L, 95% CI: −1.08 to −0.09, p = 0.02). The same was by plant sterols (MD: −0.46 mmol/L, 95% CI: −0.76 to −0.17, p < 0.01 for cholesterol and MD: −0.45 mmol/L, 95% CI: −0.74 to −0.16, p < 0.01 for low-density lipoprotein cholesterol). No heterogeneity was noticed among the studies included in these analyses. Conclusions: Available trials confirm that the addition of plant sterols or stanols has a cholesterol-lowering effect on such individuals. On the other hand, supplementation with omega-3 fatty acids effectively reduces triglycerides and might have a role in lowering the cholesterol of patients with familial hypercholesterolemia. Additional studies are needed to investigate the efficacy of cholesterol-lowering diet or the addition of soya protein and dietary fibers to a cholesterol-lowering diet in patients with familial hypercholesterolemia.

1 September 2018 in Clinical Biochemistry
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Journal Article
Closed access
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
EFElizabeth Fragopoulou
Elizabeth Fragopoulou
SASmaragdi Antonopoulou
Smaragdi Antonopoulou
DPDemosthenes Panagiotakos
Demosthenes Panagiotakos

11 March 2017 in European Journal of Nutrition
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YKYiannis Kotsis
Yiannis Kotsis
AMAnastasia Mikellidi
Anastasia Mikellidi
CACleopatra Aresti
Cleopatra Aresti
EPEleni Persia
Eleni Persia
ASAristomenis Sotiropoulos
Aristomenis Sotiropoulos
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
Purpose The aim of the study was to investigate the effect of a 6-week, low-dose bovine colostrum (BC) supplementation on exercise-induced muscle damage (EIMD) and performance decline in soccer players following the Loughborough Intermittent Shuttle Test (LIST) during a competitive season period. Methods In a double-blind, randomized, placebo-controlled design, two groups of soccer players were allocated to a 3.2 g/day of whey protein (WP, N = 8) or BC (N = 10) and performed a pre- and a post-supplementation LIST. Maximum isometric voluntary contraction, squat jump (SQJ), countermovement jump, muscle soreness, blood cell counts, creatine kinase (CK), C-reactive protein (CRP) and interleukin-6 (IL-6) were monitored for 2, 24, 48, 72 h post-LIST. Results LIST induced transient increases in leukocytes, granulocytes, CK, muscle soreness, CRP, IL-6 and declines in lymphocytes and performance indices. Supplementation resulted in a faster recovery of SQJ, CK and CRP compared to pre-supplementation kinetics (trial × time: p = 0.001, 0.056, 0.014, respectively) and lower incremental area under the curve (iAUC) for IL-6, only in the BC group [pre-: 31.1 (6.78–46.9), post-: 14.0 (−0.16 to 23.5) pg h/ml, p = 0.034]. Direct comparison of the two groups after supplementation demonstrated higher iAUC of SQJ [WP: −195.2 (−229.0 to (−52.5)), BC: −15.8 (−93.2 to 16.8) cm h, p = 0.034], a trend for lower iAUC of CK in the BC group [WP: 18,785 (4651–41,357), BC: 8842 (4807–14,802) U h/L, p = 0.081] and a significant intervention × time interaction for CRP (p = 0.038) in favor of BC. Conclusions Post-exercise EIMD may be reduced and performance better maintained by a low dose of BC administration following LIST in soccer players.

5 June 2009 in Lipids in Health and Disease
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Paraskevi DetopoulouParaskevi Detopoulou
Paraskevi Detopoulou
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
Elizabeth FragopoulouElizabeth Fragopoulou
Elizabeth Fragopoulou
DPDemosthenes Panagiotakos
Demosthenes Panagiotakos
CPChristos Pitsavos
Christos Pitsavos
SASmaragdi Antonopoulou
Smaragdi Antonopoulou
Background: Lipoprotein-associated phospholipase A2 (Lp-PLA2) also known as serum platelet activating factor acetylhydrolase (PAF-AH) activity constitutes a novel risk marker for cardiovascular disease. Leukocytes constitute one main cellular source of circulating Lp-PLA2. The aim of the present study was to evaluate the association of both serum and leukocyte PAF-AH activities with fat distribution and lean tissue. One hundred healthy volunteers without cardiovascular disease history participated in this study (n = 52 men, 44 ± 13 years and n = 48 women, 43 ± 13 years). Body composition was assessed with dual-energy X-ray absorptiometry, while anthropometrical indices were also measured. The activity of Lp-PLA2 and levels of lipid and glycemic parameters were determined in fasting samples. Results: Mean Lp-PLA2 activity was 24.8 ± 4.5 and 19.6 ± 5.0 nmol/min/mL in men and women, respectively (P < 0.001). Mean activity of PAF-AH in leukocyte homogenates was 386 ± 127 pmol/min/mg and 292 ± 92 pmol/min/mg in men and women, correspondingly (P < 0.001). In multiple regression models upper and total adiposity measures were positively associated with Lp-PLA2 activity in men after adjusting for LDL-cholesterol, age, smoking, hs-CRP and physical activity, whereas no associations were found with PAF-AH leukocyte homogenates activity. Hierarchical analysis revealed that the variables with the highest explanatory ability of Lp-PLA2 activity in men, were DXA deriving L1–L4 region of interest and arms fat (increase in R2 = 0.136, P = 0.005 and increase in R2 = 0.118, P = 0.009, respectively), followed by trunk fat and total fat. In women, no association of body composition variables with Lp-PLA2 nor PAF-AH leukocyte homogenates activity was found. Conclusion: Lp-PLA2 activity is differentiated across levels of adiposity and topology of adipose tissue, whereas no association was found regarding PAF-AH leukocyte homogenates activity. Our findings suggest that Lp-PLA2 may compensate for the adiposity-associated increases in inflammatory and oxidative burden, in men.

Verified
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DADionysia Argyropoulou
Dionysia Argyropoulou
NGNickos D Geladas
Nickos D Geladas
Tzortzis NomikosTzortzis Nomikos
Tzortzis Nomikos
Vassilis PaschalisVassilis Paschalis
Vassilis Paschalis
Medical and technology development have drastically the improved quality of life and, consequently, life expectancy. Nevertheless, the more people who enter the third-age, the more geriatric syndromes expand in the elderly. Sarcopenia and Type 2 diabetes mellitus (T2DM) are common diseases among the elderly and the literature has extensively studied these two diseases separately. Recent evidence, however, revealed that there is a bidirectional relationship between sarcopenia and T2DM. The aims of the present review were: (1) to present diet and exercise interventions for the management of sarcopenia and T2DM and (2) identify which diet and exercise interventions can be used simultaneously in order to effectively deal with these two disorders. Exercise and a balanced diet are used as effective countermeasures for combating sarcopenia and T2DM in older adults based on their bidirectional relationship. Lifestyle changes such as exercise and a balanced diet seem to play an important role in the remission of the diseases. Results showed that chronic exercise can help towards glycemic regulation as well as decrease the incidence rate of muscle degradation, while diet interventions which focus on protein or amino acids seem to successfully treat both disorders. Despite the fact that there are limited studies that deal with both disorders, it seems that a combined exercise regime (aerobic and resistance) along with protein intake > 1gr/kg/d is the safest strategy to follow in order to manage sarcopenia and T2DM concurrently.