• Assessment of the relationship between macronutrient intake and browning of white fat in adult males

      Carrillo, Andres E; Dinas, Petros C; Valente, Angelica; Granzotto, Marnie; Rossato, Marco; Vettor, Roberto; Davies, Natalie A; Jamurtas, Athanasios Z; Koutedakis, Yiannis; Metsios, George S; et al. (Ovid Technologies (Wolters Kluwer Health), 2017-05-01)
      Research conducted in rodents and humans present conflicting results on the relationship between caloric intake and the browning of subcutaneous white adipose tissue (scWAT). For example, exercise combined with caloric restriction did not change browning indices measured from human scWAT samples. In another study, caloric restriction in mice resulted in the browning of both scWAT and visceral white adipose tissue. Few investigators, however, have examined the relationship between differences in macronutrient intake and browning processes of human scWAT.
    • Circulating Sclerostin responses to acute weight and non weight bearing sport activity in pre adolescent males

      Jamurtas, Athanasios Z; Leontsini, Diamanda; Avloniti, Alexandra; Vlachopoulos, Dimitris; Stampoulis, Theodoros; Chatzinikolaou, Athanasios; Gracia-Marco, Luis; Ubago-Guisado, Esther; Makris, Konstantinos; Tournis, Symeon; et al. (Ovid Technologies (Wolters Kluwer Health), 2017-05-01)
      Mechanical loading, i.e. physical activity and/or exercise, promotes bone formation during growth. Sclerostin, a glycoprotein, mediates osteocytes' response to mechanical loading by inhibiting the Wnt/lf-catenin pathway thereby inhibiting bone formation.
    • The effects of pre-exercise corinthian currants supplementation on antioxidant responses

      Jamurtas, Athanasios Z; Deli, Chariklia K; Fatouros, Ioannis G; Selemekou, Maria; Papoutsis, Alexandros; Koutedakis, Yiannis; Karathanos, Vaios (Ovid Technologies (Wolters Kluwer Health), 2016-05)
      Τhe use of nutritional supplements before and during a sporting event, especially of a prolonged nature, is very common among competitors and routinely advised by exercise professionals. Corinthian currants have a high carbohydrate content making them a potentially ideal carbohydrate source for prolonged exercise. However, their effectiveness as an ergogenic aid has never been studied.
    • Enhanced erythrocyte antioxidant status following an 8-week aerobic exercise training program in heavy drinkers

      Jamurtas, Athanasios Z; Georgakouli, Kalliopi; Manthou, Eirini; Georgoulias, Panagiotis; Deli, Chariklia; Koutedakis, Yiannis; Theodorakis, Yannis; Fatouros, Ioannis (American College of Sports Medicine, 2018-05-31)
      Alcohol-induced oxidative stress is involved in the development and progression of various pathological conditions and diseases whereas exercise training has been shown to improve redox status, thus attenuating oxidative stress-associated disease processes. PURPOSE: to evaluate the effect of an exercise training program on blood redox status in heavy drinkers. METHODS: Eleven sedentary, heavy drinking men participated in an intervention where they completed an 8-week supervised aerobic training program of moderate intensity. Blood samples were collected before, during (week 4) and after intervention and analyzed for total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), uric acid (UA), bilirubin, reduced glutathione (GSH) and catalase activity. RESULTS: Catalase activity increased (p<0.05) after 8 weeks (340.7+13.3 U mg/Hb) of intervention compared to week 4 (299.5+18.7 U mg/Hb). GSH increased (p<0.05) after 8 weeks of intervention (1.22+0.16 μmol/g Hb) compared to the control condition (1.11 + 0.17 μmol/g Hb) and to week 4 (1.11 + 0.15 μmol/g Hb ). TAC, UA, bilirubin, TBARS and PC did not significantly change at any time point. CONCLUSION: An 8-week aerobic training program enhanced erythrocyte antioxidant status in heavy drinkers, indicating that aerobic training may attenuate pathological processes caused by alcohol-induced oxidative stress.
    • Thermogenic capacity of human white-fat: the actual picture

      Dinas, Petros C; Krase, Argyro; Nintou, Eleni; Georgakopoulos, Alexandros; Granzotto, Marnie; Metaxas, Marinos; Karachaliou, Eleni; Rossato, Marco; Vettor, Roberto; Georgoulias, Panagiotis; et al. (MDPI AG, 2019-08-29)
      Cold exposure and exercise may increase thermogenic capacity of white adipose tissue (WAT), which could subsequently enhance energy expenditure and body weight loss. We aimed to identify possible alterations in uncoupling protein 1 (UCP1)—the main biomarker of thermogenic activation—in human WAT due to both cold exposure and exercise, as well as the link between environmental temperature and thermogenic capacity of human WAT. MATERIAL &amp; METHOD: We conducted four human experimental studies and two systematic reviews and meta-analyses—PROSPERO registration CRD42019120116, CRD42019120213. RESULTS: UCP1 mRNA was higher in winter than in summer [t(30) = 2.232, p = 0.03] in human WAT and our meta-analysis showed a main effect of cold exposure on human UCP1 mRNA [standard mean difference (Std-md) = 1.81, confidence interval (CI) = 0.50–3.13, p = 0.007]. However, UCP1 mRNA/protein expressions displayed no associations with %fat mass or BMI (p &gt; 0.05, Cohen’s f2 &lt; 0.20). Both a 2-hour cooling and a non-cooling protocol preceding the positron emission tomography/computed tomography (PET/CT) measurements revealed no association between environmental temperature and standardised uptake value (SUVmax) of human WAT, as well as no mean differences in SUVmax-WAT-activity between winter and summer. An 8-week exercise program had no effect on UCP1 of human WAT or on body composition. Our meta-analysis also revealed: (a) no effect of chronic exercise on human UCP1 mRNA, (b) a main effect of chronic exercise on UCP1 protein concentrations (Std-md = 0.59, CI = 0.03–1.16, p = 0.04) and UCP1 mRNA (Std-md = 1.76, CI = 0.48–3.04, p = 0.007) in WAT of normal diet animals, c) a main effect of chronic exercise on UCP1 mRNA (Std-md = 2.94, CI = 0.24–5.65, p = 0.03) and UCP1 protein concentrations (Std-md = 2.06, CI = 0.07–4.05, p = 0.04) of high-fat diet animals. CONCLUSIONS: Cold exposure represents a main stimulus for increased thermogenic capacity in human white adipocytes; however, this may have no impact on body weight loss. Chronic exercise may represent no major stimulus for UCP1 induced in human white adipocytes, while in animals it increases UCP1 gene independently of their diet. Therefore, evidence from animal studies regarding UCP1 gene activation in white adipocytes may not be applicable in humans. Finally, the identification of human WAT thermogenic capacity via PET/CT examination may be optimal with both a cooling and a non-cooling protocol.