Kalliopi Georgakouli

Effects of acute exercise on liver function and blood redox status in heavy drinkers

Excessive alcohol consumption can induce oxidative stress, resulting in the development of several diseases. Exercise has been reported to prevent and/or improve a number of health issues through several mechanisms, including an improvement in redox status. It has also been previously suggested that exercise can help individuals with alcohol use disorders reduce their alcohol intake; however, research in this field is limited. The aim of the present study was to investigage the effects of acute exercise of moderate intensity on the liver function and blood redox status in heavy drinkers. For this purpose, a total of 17 heavy drinkers [age, 31.6±3.2 years; body mass index (BMI), 27.4±0.8 kg/m2; experimental group (EG)] and 17 controls [age, 33.5±1.3 years; BMI, 26.1±1.4 kg/m2; control group (CG), who did not exceed moderate alcohol consumption], underwent one trial of acute exercise of moderate intensity (50–60% of the heart rate reserve) for 30 min on a cycle ergometer, following an overnight fast, and abstaining from smoking and alcohol consumption. Blood samples were obtained before and immediately after exercise for later determination of the indices of liver function and blood redox status. The subjects in the EG had significantly higher (p<0.05) baseline γ-glutamyl transferase (γ-GT) levels compared to the subjects in the CG. Exercise thus resulted in significantly higher γ-GT levels (p<0.005) only in the EG. No significant differences in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) baseline levels were observed between the 2 groups. Following exercise, the AST levels increased significantly (p<0.001) in both groups, whereas the ALT levels increased significantly (p<0.01) only in the EG. The baseline glutathione (GSH) levels were significantly lower (p<0.05) and remained low following exercise in the EG. In addition, we observed a trend for higher (p=0.07) baseline levels of thiobarbituric acid-reactive substances (TBARS), which remained elevated post-exercise in the EG compared to the CG. Significantly increased post-exercise total antioxidant capacity (TAC; p<0.01) and uric acid (UA; p<0.05) levels were noted in the CG, whereas the TAC (p=0.06) and UA (p=0.08) levels increased and approached significance post-exercise in the EG. No significant differences in the baseline levels of total bilirubin and protein carbonyl were observed between the 2 groups, even post-exercise. Thus, the findings of the present study indicate that even though heavy drinkers may be prone to oxidative stress, their exercise-induced antioxidant response is similar to that of individuals who do not drink heavily.

Beta Endorphin and Alcohol Urge Responses in Alcoholic Patients Following an Acute Bout of Exercise

Objective: To examine the effects of low intensity exercise on beta endorphin (β-E) levels and urge for alcohol in alcoholic patients. Methods: Nine alcoholic patients (M= 41.2 + 6.7 yrs) and 9 healthy controls (M=38.2 + 10.7 yrs) exercised for 30 minutes at a low intensity (61.1 + 4.9 % of their maximum heart rate). Blood was collected prior to and immediately following exercise and was analyzed for a complete blood count (CBC), β-E and lactic acid. Furthermore, an alcohol urge questionnaire was filled by the subjects prior to and immediately following exercise. Results: Data analysis revealedthat β-E levels were significantly lower in alcoholic patients whereas exercise resulted in significant (p< .001) increases in β-E (pre: 1.57 + 0.39 pmol/L, post: 4.8 + 1.6 pmol/L) only in alcoholic patients. Lactic acid increased significantly in both groups. There was a 17% decrease in alcohol urge in alcoholic patients without however this difference being significant. No differences in the parameters assessed through the CBC were seen between the two groups whereas exercise resulted in significant increases in red blood cells, hemoglobin and hematocrit in both groups. Conclusion: These results indicate that a bout of low intensity exercise affects the endogenous opioids in alcoholic patients.

Role of exercise in the treatment of alcohol use disorders (Review)

Excessive alcohol use can cause harmful effects on the human body, which are associated with serious health problems, and it can also lead to the development of alcohol use disorders (AUDs). There is certain evidence that physical exercise positively affects excessive alcohol use and the associated problems by leading to reduced alcohol intake. A literature search was conducted using the databases PubMed, Medline and Web of Science. The search terms used as keywords were: Addiction, abuse, alcohol use disorders, exercise training, β-endorphin, opioids, brain, ethanol and alcohol. The current study presents the studies that reported on the use of exercise in the treatment of AUDs between 1970 and 2015. The potential psychological and physiological mechanisms that contribute to the action of exercise were also reviewed, highlighting the role of β-endorphin and the hypothalamic-pituitary-adrenal axis in AUDs and the possible association among physical activity, the endogenous opioid system and the desire for alcohol. Only 11 studies were identified that refer to the effect of exercise on alcohol consumption and/or the associated outcomes. Six of those studies concluded that exercise may have a positive impact towards alcohol consumption, abstinence rates or the urge to drink. One of those studies also indicated that a bout of exercise affects the endogenous opioids, which may be associated with the urge to drink. Another 3 studies indicated that responses to acute exercise in individuals with AUDs are different compared to those in healthy ones. Generally, despite limited research data and often contradictory results, there is certain early promising evidence for the role of exercise as an adjunctive tool in the treatment of AUDs. Physiological and biochemical parameters that would confirm that exercise is safe for individuals with AUDs should be examined in future studies.

The Effects of an Olive Fruit Polyphenol-Enriched Yogurt on Body Composition, Blood Redox Status, Physiological and Metabolic Parameters and Yogurt Microflora

In the present study we investigated the effects of an olive polyphenol-enriched yogurt on yogurt microflora, as well as hematological, physiological and metabolic parameters, blood redox status and body composition. In a randomized double-blind, crossover design, 16 (6 men, 10 women) nonsmoking volunteers with non-declared pathology consumed either 400 g of olive fruit polyphenol-enriched yogurt with 50 mg of encapsulated olive polyphenols (experimental condition—EC) or 400 g of plain yogurt (control condition—CC) every day for two weeks. Physiological measurements and blood collection were performed before and after two weeks of each condition. The results showed that body weight, body mass index, hip circumference and systolic blood pressure decreased significantly (p < 0.05) following the two-week consumption of yogurt regardless of condition. A tendency towards significance for decreased levels of low density lipoprotein (LDL) cholesterol (p = 0.06) and thiobarbituric acid reactive substances (p < 0.05) following two weeks of polyphenol-enriched yogurt consumption was observed. The population of lactic acid bacteria (LAB) and production of lactate in yogurt were significantly enhanced after addition of olive polyphenols, contrary to the population of yeasts and molds. The results indicate that consumption of the polyphenol-enriched yogurt may help individuals with non-declared pathology reduce body weight, blood pressure, LDL cholesterol levels and lipid peroxidation, and promote growth of beneficial LAB.

α-Lipoic acid supplementation up-regulates antioxidant capacity in adults with G6PD deficiency

The purpose of this study was to examine the effect of α-lipoic acid (LA) supplementation on blood redox status in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Eight adults with G6PD deficiency (D group) and eight controls with normal G6PD levels (N group) participated in this study. Participants received LA (600 mg/day) for 28 days. At baseline, 2 and 4 weeks after supplementation, venous blood was collected for analysis of reduced glutathione (GSH), catalase, protein carbonyls (PC), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), bilirubin, uric acid (UA) and hemoglobin (Hb) levels. Baseline GSH was lower (P<0.05) in D compared to N group whereas LA supplementation for 2 and 4 weeks increased significantly (P<0.05) GSH levels in both groups. Catalase and TAC increased (P<0.05) in both groups following 2 and 4 weeks of supplementation. Baseline TBARS values were higher (P<0.05) in D compared to N group while LA supplementation reduced (P<0.05) TBARS and PC in both groups. There were no differences for UA at baseline between the two groups but LA supplementation increased significantly UA levels only in the D group. Bilirubin and Hb were unchanged. These results indicate that LA supplementation may modulate redox status regardless G6PD deficiency.

Iron Supplementation Effects on Redox Status following Aseptic Skeletal Muscle Trauma in Adults and Children

Exercise-induced skeletal muscle microtrauma is characterized by loss of muscle cell integrity, marked aseptic inflammatory response, and oxidative stress. We examined if iron supplementation would alter redox status after eccentric exercise. In a randomized, double blind crossover study, that was conducted in two cycles, healthy adults (n = 14) and children (n = 11) received daily either 37 mg of elemental iron or placebo for 3 weeks prior to and up to 72 h after an acute eccentric exercise bout. Blood was drawn at baseline, before exercise, and 72 h after exercise for the assessment of iron status, creatine kinase activity (CK), and redox status. Iron supplementation at rest increased iron concentration and transferrin saturation (p < 0.01). In adults, CK activity increased at 72 h after exercise, while no changes occurred in children. Iron supplementation increased TBARS at 72 h after exercise in both adults and children; no changes occurred under placebo condition. Eccentric exercise decreased bilirubin concentration at 72 h in all groups. Iron supplementation can alter redox responses after muscle-damaging exercise in both adults and children. This could be of great importance not only for healthy exercising individuals, but also in clinical conditions which are characterized by skeletal muscle injury and inflammation, yet iron supplementation is crucial for maintaining iron homeostasis. This study was registered at Clinicaltrials.gov Identifier: NCT02374619.

Self-regulation strategies may enhance the acute effect of exercise on smoking delay

The present study examined the acute effect of a moderate intensity aerobic exercise session combined with self-regulation on smoking delay in physically inactive smokers. Participants were 11 adults (5 males and 6 females) that completed three experimental conditions: control, exercise, and exercise using self-regulation strategies (SR). Following the experimental treatment smoking for the two exercise conditions delayed significantly more than for the control condition; in addition exercise SR delayed smoking marginally more that the plain exercise condition. Findings supported previous research that acute exercise reduces cravings to smoke, and suggests that the use of self-regulation strategies may strengthen exercise for smoking cessation interventions.

Exercise training reduces alcohol consumption but does not affect HPA-axis activity in heavy drinkers

BACKGROUND It has been suggested that physical exercise could have potential beneficial effects in substance abusers, which are based on both physiological and psychological theories. Although a few studies have examined the effect of exercise on alcohol intake and fitness in individuals with alcohol use disorders (AUDs), there is a gap in the literature concerning the physiological and biochemical mechanisms that could be affected by physical exercise in this population. PURPOSE The purpose of the present study was to examine physiological and biochemical responses to exercise after an 8-week supervised exercise training (ET) intervention in heavy drinkers. The investigation was mainly focused on the relationship among exercise, opioids, the hypothalamic-pituitary-adrenal axis (HPA) activity and heavy alcohol drinking. METHODS Eleven (Age: 30.3±3.5yrs; Body Mass Index: 28.4±0.86kg/m2) male heavy drinkers volunteered to participated in an 8-week supervised intervention of moderate intensity exercise (50-60% of Heart Rate Reserve). All participants were exhibiting low physical activity and used to drink heavily. Before intervention, the participants were asked to record their daily alcohol intake without changing their physical activity levels for 4weeks (control condition). During the 8-week supervised ET intervention, participants were recording their daily alcohol intake and were motivated to increase gradually the duration and frequency of ET. Blood samples were collected prior to and after 4weeks of the control condition, the day before the beginning of the ET intervention, and at the end of the 4th and 8th week of ET intervention. Blood samples were analyzed for β-E, epinephrine, norepinephrine, adrenocorticotropin, cortisol, gamma-glutamyl transferase (γ-GT), aspartate transaminase and alanine transaminase. Physiological and alcohol-related indices were also examined. RESULTS The 8-week supervised ET intervention resulted in reduced alcohol consumption, reduced γ-GT levels, and fitness improvement in heavy drinker. ET intervention did not significantly change the hormonal responses. CONCLUSION The results indicate that physical exercise could act as a healthy habit that can help individuals with AUDs reduce alcohol intake and improve health status; however, this is not related with changes in hormones associated with the HPA-axis.

An initial investigation of smokers’ urges to smoke and their exercise intensity preference: A mixed-methods approach

Abstract The purpose of this study was to examine whether smokers preferred a “self-selected” form of physical activity (PA) in which they were allowed to determine themselves the intensity of PA or preferred a “set” form of PA in which the instructor chose the exercise intensity for them. In addition, we examined effects of ‘set” and “self-selected” intensity exercise, on urges to smoke. Participants were 20 (mean age = 27.10 ± 7.37) adults, non-physically active, heavy smokers. Four of them were also interviewed. Results demonstrated that smokers exhibited an enhanced preference for “self-selected” forms of PA as opposed to “set” forms of PA. Smoking urge was significantly lower immediately after exercise in both conditions, returned to baseline levels at 30 min post-exercise, and increased further at 60 min post-exercise. Qualitative data supported the quantitative findings and gave insight to dimensions that needs to be taken under account when we design exercise programs for smokers. The implication of the overall findings is that smoking cessation and motivation for PA participation can be increased by allowing smokers to select intensity of PA programs.

Glycemic Response of a Carbohydrate-Protein Bar with Ewe-Goat Whey

In this study we examined the glycaemic index (GI) and glycaemic load (GL) of a functional food product, which contains ewe-goat whey protein and carbohydrates in a 1:1 ratio. Nine healthy volunteers, (age, 23.3 ± 3.9 years; body mass index, 24.2 ± 4.1 kg·m2; body fat %, 18.6 ± 10.0) randomly consumed either a reference food or amount of the test food both with equal carbohydrate content in two visits. In each visit, seven blood samples were collected; the first sample after an overnight fast and the remaining six at 15, 30, 45, 60, 90 and 120 min after the beginning of food consumption. Plasma glucose concentration was measured and the GI was determined by calculation of the incremental area under the curve. The GL was calculated using the equation: test food GI/100 g available carbohydrates per test food serving. The GI of the test food was found to be 5.18 ± 3.27, while the GL of one test food serving was 1.09 ± 0.68. These results indicate that the tested product can be classified as a low GI (<55) and low GL (<10) food. Given the health benefits of low glycaemic response foods and whey protein consumption, the tested food could potentially promote health beyond basic nutrition.