Antioxidant status and oxidative stress at rest and in response to acute exercise in judokas and sedentary men.

It is well recognized that acute strenuous exercise is accompanied by an increase in free-radical production and subsequent oxidative stress, in addition to changes in blood antioxidant status. Chronic exercise provides protection against exercise-induced oxidative stress by upregulating endogenous antioxidant defense systems. Little is known regarding the protective effect afforded by judo exercise. Therefore, we determined antioxidant and oxidative stress biomarkers at rest and in response to acute exercise in 10 competitive judokas and 10 sedentary subjects after mixed exercise (anaerobic followed by aerobic). The subjects performed a Wingate test, followed by 30 minutes of aerobic exercise performed at 60% of maximal aerobic power. Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the physical exercise (P0), and at 5 (P5), 10 (P10), and 20 (P20) minutes postexercise. The measured parameters included the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione reductase, in addition to α-tocopherol, and total antioxidant status. Malondialdehyde was measured as a representation of lipid peroxidation. At rest, the judokas had higher values for all antioxidant and oxidative stress markers as compared to the sedentary subjects (p < 0.05). Plasma concentrations of all parameters except for α-tocopherol increased significantly above resting values for both the judokas and sedentary subjects (p < 0.05) and remained elevated at 20 minutes postexercise. A significant postexercise decrease was observed for α-tocopherol (p < 0.05) at P20 for judokas and at P5 for sedentary subjects. These data indicate that competitive judo athletes have higher endogenous antioxidant protection compared to sedentary subjects. However, both groups of subjects experience an increase in exercise-induced oxidative stress that is not different.

Effect of energy expenditure and training status on leptin response to sub-maximal cycling.

We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR) and 7 untrained (UTR) subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively) were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP). Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively. [Lep] was related to body fat percentage and body fat mass in TR (r = 0. 84, p < 0.05 and r = 0.93, p < 0.01) and in UTR (r = 0.89, p < 0.01 and r = 0.92, p < 0. 01, respectively). [Lep] did not change significantly during both protocols for both groups but was lower (p < 0.05) in all sampling in TR when compared to UTR. Plasma [I] decreased (p < 0.01) and [GH] increased (p < 0.01) significantly during both SP and PP and these hormones remained lower (I: p < 0.01) and higher (GH: p < 0.01) than pre-exercise levels after a 2-h recovery period, returning to base-line at 24-h recovery. Plasma [La] increased (p < 0.01) during both protocols for TR and UTR. There was no significant change in [C] and [G] during and after both protocols for all subjects. It is concluded that 1) leptin is not sensitive to acute short or prolonged sub-maximal exercises (with energy expenditure under 800 kcal) in volleyball/ anaerobically trained athletes as in untrained subjects, 2) volleyball athletes showed significantly lower resting and exercise leptin response with respect to untrained subjects and 3) it appears that in these anaerobically trained athletes leptin response to exercise is more sensitive to the level of energy expenditure than hormonal or metabolic modifications induced by acute exercise. Key pointsTrials concerning acute exercise and leptin indicated discrepant results.Acute exercise with energy expenditure higher than 800 kcal can decrease leptinemia.Elite volleyball players presented decreased leptin levels than untrained subjects.

[Graves's disease in children and adolescent: study of seven cases]. / La maladie de Basedow chez l'enfant et l'adolescent: etude de sept cas.

BACKGROUND: In spite of its rarity in the paediatric age, Graves' disease constitutes the principal aetiology of hyperthyroidism in child. AIM: Our goal is to analyze the clinical and evolutive particularities of Graves's disease in children. METHODS: We studied retrospectively seven cases of Graves' disease in children enrolled in the pediatrics department of Sousse during ten years period (1993-2002). RESULTS: There were six girls and one boy (sex - ratio = 0.16) aged 4.5 to 16 years (mean age: nine years and one month). The diagnosis has been established clinically on the presence of classic symptoms of the illness associated to the biological and radiological findings. As part of research of possible associations with this illness, we observed solely in a case, in addition of Graves's disease, the coexistence of Down syndrome and coeliac disease, rarely described. Among the HLA antigens predisposing the Graves's disease, we only found HLA B8 antigen in a patient. The evolution under antithyroid drug treatment (ATD) has been marked by fast disappearance of functional signs in all patients. However, biological and clinical euthyroidism was more difficult to achieve. The treatment has been stopped in only one patient after 40 months period. CONCLUSION: Graves' disease is usually easy to recognize but difficult to treat. Radical treatments (thyroidectomy or radioactive iodine therapy) are indicated in second intention after having tempted ATD beforehand.

Impact of diet, exercise end diet combined with exercise programs on plasma lipoprotein and adiponectin levels in obese girls.

We studied the effect of three programs, diet restriction (D), individualized exercise training (E) at the maximal lipid oxidation point (LIPOXmax) and diet combined with exercise (D+E), on body mass, plasma lipoprotein and adiponectin levels in obese girls. Eighteen obese adolescents girls aged 12-14 years were studied. A longitudinal intervention was carried out, consisting of a two-month diet (D; -500 kcal·day-1), of individualized exercise (E; 4 days/week, 90 min·day-1) and of diet combined with exercise (D+E). Body mass, body mass index (BMI), body fat mass, waist circumference, substrate crossover point, LIPOXmax point, homeostasis model assessment (HOMA-IR) index, fasting levels of lipids and circulatory adiponectin, were measured in all subjects before and after the program. In subjects of the D+E group, body mass, BMI, body fat mass, waist circumference, HOMA-IR, low-density lipoprotein cholesterol (LDL-C) and total cholesterol / high-density lipoprotein cholesterol (TC/HDL-C) ratio were significantly lower, and HDL-C and adiponectin were higher after the program than that of subjects in the D or E groups. Diet/exercise improved the ability to oxidize lipids during exercise (crossover point: + 18.5 ± 3.4 of % Wmax; p < 0.01 and fat oxidation rate at LIPOXmax: + 89.7 ± 19.7 mg·min(-1); p < 0.01). In the D+E group, significant correlations were found between changes in body mass and adiponectin and between changes in the TC/HDL-C ratio and LIPOXmax. These findings show that the combined program of diet restriction and individualized exercise training at the LIPOXmax point is necessary to simultaneously improve body mass loss, adiponectin levels, as well as metabolic parameters, in obese girls. Key pointsDiet combined with exercise training improved body composition, adiponectin levels and metabolic parameters in obese girls.Diet only decreases body mass and LDL-C without improving fat oxidation and HDL- C.Individualized exercise training at LIPOXmax point improved the HDL-C and the circulatory adiponectin levels with any change of LDL-C and body composition.

Leptin, its implication in physical exercise and training: a short review.

Leptin, a hormone synthesized by fat tissue had been noted to regulate energy balance and metabolism and thus to influence body weight. The influence of acute exercise and chronic exercise training on circulating leptin and its relationship with hormonal and metabolic changes that induce energy balance are presented. Research that has examined the influence of exercise under various experimental conditions on leptin and the conflicts in the literature are presented. It appears that a significant caloric perturbation (> 800 kcals) is necessary for acute exercise to result in a significant reduction in leptin. In contrast, exercise training can result in a leptin decline but typically this manifests a reduction in adipose tissue stores. In addition, future directions are presented. Key PointsPhysical exercise and training have both inhibitory and stimulatory effects on leptin.Exercise with energy expenditure higher than 800 kcal can decrease leptinemia.Acute training may cause a decline in circulating leptin levels.

Parathyroid hormone and physical exercise: a brief review.

Parathyroid hormone (PTH) is the major hormone regulating calcium metabolism and is involved in both catabolic and anabolic actions on bone. Intermittent PTH exposure can stimulate bone formation and bone mass when PTH has been injected. In contrast, continuous infusion of PTH stimulates bone resorption. PTH concentration may be affected by physical exercise and our review was designed to investigate this relationship. The variation in PTH concentration appears to be influenced by both exercise duration and intensity. There probably exists a stimulation threshold of exercise to alter PTH. PTH regulation is also influenced by the initial bone mineral content, age, gender, training state, and other hormonal and metabolic factors (catecholamines, lactic acid and calcium concentrations). Key PointsPhysical exercise can improve PTH secretion.PARATHYROID HORMONE HAS BOTH ANABOLIC AND CATABOLIC EFFECTS ON BONE: intermittent treatment of PTH is anabolic whereas continuous treatment is catabolic.

Changes in six-minute walking distance during pulmonary rehabilitation in patients with COPD and in healthy subjects.

BACKGROUND: The six-minute walking distance (6MWD) test has demonstrated validity and reliability to assess changes in functional capacity following pulmonary rehabilitation in patients with chronic obstructive lung disease. However, no attempt has been made to establish an iterative measurement of 6MWD during the overall period of pulmonary rehabilitation. Therefore, the aim of this study was to evaluate the impact of a twelve-week rehabilitation program on the iterative weekly measurement of 6MWD in chronic obstructive pulmonary disease (COPD) patients and healthy subjects. METHODS: Twenty-six patients with COPD and nine age-matched healthy subjects were studied. Measurements were taken at baseline and after twelve weeks except for the 6MWD. The exercise measurements included a six-minute walking test (6MWT) and an incremental exercise test. Oxygen saturation, heart rate, and dyspnea will be monitored during all these tests. RESULTS: At baseline there were significant differences between groups, except in age, body mass index, and oxygen saturation. After 12 weeks, there was no significant change in lung function in patients with COPD and healthy subjects. The 6MWD, peak oxygen uptake (.)VO(2peak) and anaerobic threshold increased significantly after training in both groups (P < 0.01). The averaged trace of the 6MWD of patients with COPD and healthy subjects was followed-up respectively by a logarithmic and linear fitting. 6MWD showed a plateau after eight weeks in patients with COPD, however, it increased continually overall in healthy subjects. CONCLUSION: Both patients with COPD and healthy subjects demonstrated functional responses to training but with somewhat different patterns in quality of the improvement of the 6MWD.

Effect of hyperthermia and physical activity on circulating growth hormone.

The aim of this study was to differentiate the effects of hyperthermia and physical activity on circulating growth hormone (GH) secretion. Nine healthy volunteer adults performed two 40 min exercise trials and two 50 min passive standing trials. The exercise was performed in either thermo-neutral (N-Ex: air temperature 18 degrees C, air humidity 40%, and wet bulb globe temperature (WBGT) 17.7 degrees C) or hot environmental conditions (H-Ex: air temperature 33 degrees C, air humidity 30%, and WBGT 34.6 degrees C). The passive exposure trials were also performed in either a comfortable (N-P: air temperature 18 degrees C, air humidity 40%, and WBGT 17.7 degrees C) or a hot climatic chamber (H-P: air temperature 40 degrees C, air humidity 100%, and WBGT 97.1 degrees C). Plasma GH, plasma volume (PV), tympanic temperature (Tty), and body mass loss (BML) were measured before and after each trial. The decrease in PV was significantly higher during H-Ex and H-P sessions than during N-Ex and N-P sessions. Comparisons showed significantly lower BML in the N-Ex session (1.5% +/- 0.3%) than in the H-Ex and H-P sessions (2.1% +/- 0.3% and 1.9% +/- 0.2%, respectively) (p < 0.001). The rise in Tty was significantly higher during the H-P session (2.9 +/- 0.4 degrees C) (p < 0.001) when compared with the other sessions. Plasma GH concentration increased significantly during all the trials, particularly during the H-Ex session (45 +/- 7 ng.mL-1) (p < 0.01). Both exercise and heat exposure, separately, are sufficient to increase significantly the plasma GH concentration, and their combined effect induced a highly synergistic rise in GH.