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Collomp K.,University Paris - Sud | Zorgati H.,University Paris - Sud | Cottin F.,University Paris - Sud | Do M.-C.,University Paris - Sud | And 5 more authors.
Hormone and Metabolic Research | Year: 2015

Glucocorticoids are among the most commonly used drugs. They are widely administered for acute and chronic musculoskeletal pain, as well as for several other pain syndromes, although their therapeutic use is sometimes diverted for doping purposes. Their time-course effects on hormonal and inflammatory responses nevertheless remain poorly understood, both at rest and during exercise. We therefore studied the alterations induced by 1 week of prednisone treatment (60 mg daily) in recreationally trained male athletes after 2 days (i. e., acute) and 7 days (i. e., short-term). Hormonal (i. e., DHEA, DHEA-S, aldosterone, and testosterone) and pro- and anti-inflammatory markers (i. e., IL-6, IL-10, and IL-1β) were investigated at rest and after resistance exercise. A significant decrease in DHEA and DHEA-S (p<0.01) without change in the DHEA/DHEA-S ratio, aldosterone, or testosterone was demonstrated after acute prednisone intake. A significant increment in IL-10 and a significant decrement in IL-6 (p<0.05) were also observed with prednisone both at rest and during exercise, without significant change in IL-1β. Continued prednisone treatment led to another significant decrease in both DHEA and DHEA-S (p<0.05), whereas no change in the inflammatory markers was observed between days 2 and 7. Our data demonstrate that the anti-inflammatory effects of prednisone were maximal and stable from the beginning of treatment, both in rest and exercise conditions. However, hormonal concentrations continued to decline during short-term intake. Further studies are needed to determine the effects of hormonal time-course alterations with longer glucocorticoid treatment and the clinical consequences. © Georg Thieme Verlag KG Stuttgart, New York.


PubMed | University Grenoble Alpes, AFLD., Institute Of Recherche Biomedicale Des Armees, French Institute of Health and Medical Research and IRBA.
Type: | Journal: Journal of applied physiology (Bethesda, Md. : 1985) | Year: 2016

We investigated the effects of chronic hypoxia on the maximal use of and sensitivity of mitochondrial to different substrates in rat slow-oxidative (soleus, SOL) and fast-glycolytic (extensor digitorum longus, EDL) muscles. We studied mitochondrial respiration in situ in permeabilized myofibers, using pyruvate, octanoate, palmitoyl-carnitine (PC) or palmitoyl-coenzyme A (PCoA). The hypophagia induced by hypoxia may also alter metabolism. We therefore used a group of pair-fed rats (reproducing the same caloric restriction as observed in hypoxic animals) in addition to the normoxic control fed ad libitum. The resting respiratory exchange ratio decreased after 21 days of exposure to hypobaric hypoxia (simulated elevation of 5,500 m). The respiration of pyruvate and octanoate were unaffected. By contrast, the maximal oxidative respiratory rate for PCoA, the transport of which depends on CPT-1, decreased in the rapid-glycolytic EDL and increased in the slow-oxidative SOL, although hypoxia improved affinity for this substrate in both muscle types. PC and PCoA were oxidized similarly in normoxic EDL, whereas chronic hypoxia limited transport at the CPT-1 step in this muscle. The effects of hypoxia were mediated by caloric restriction in the SOL, and by hypoxia itself in the EDL. We conclude that improvements in mitochondrial affinity for PCoA, a physiological long-chain fatty acid, would facilitate fatty-acid use at rest after chronic hypoxia independently of quantitative alterations of mitochondria. Conversely, decreasing the maximal oxidation of PCoA in fast-glycolytic muscles would limit fatty-acid use during exercise.


Labsy Z.,University Paris - Sud | Prieur F.,University Paris - Sud | Le Panse B.,University Paris - Sud | Do M.-C.,University Paris - Sud | And 3 more authors.
Stress | Year: 2013

Diurnal patterns of cortisol and dehydroepiandrosterone (DHEA) secretion, the two main peripheral secretory products of the hypothalamic-pituitary-adrenal neuroendocrine stress axis, have been well characterized in rest conditions but not in relation to physical exercise. The purpose of this investigation was therefore to determine the effects of an intense 90-min aerobic exercise on the waking diurnal cortisol and DHEA cycles on three separate days [without exercise, with morning exercise (10:00-11:30 h), and with afternoon exercise (14:00-15:30 h)] in nine recreationally trained soccer players. Saliva samples were collected at awakening, 30 min after awakening, and then every 2 h from 08:00 to 22:00 h. A burst of secretory activity was found for cortisol (p < 0.01) but not for DHEA after awakening. Overall, diurnal decline for both adrenal steroids was observed on resting and exercise days under all conditions. However, there was a significant increase in salivary cortisol concentrations on the morning-exercise and afternoon-exercise days at, respectively, 12:00 h (p < 0.05) and 16:00 h (p < 0.01), versus the other trials. This acute response to exercise was not evident for DHEA. The results of this investigation indicate that 90 min of intense aerobic exercise does not affect the circadian pattern of salivary adrenal steroids in recreationally trained athletes over a 16-h waking period, despite a transitory increase in post-exercise cortisol concentration. Further studies are necessary to determine whether these results are applicable to elite athletes or patients with cortisol or DHEA deficiency. © Informa Healthcare USA, Inc.


Le Panse B.,University Paris - Sud | Labsy Z.,University Paris - Sud | Baillot A.,University Paris - Sud | Vibarel-Rebot N.,University Paris - Sud | And 4 more authors.
Steroids | Year: 2012

The purpose of this study was to assess changes in the steroid hormone levels of elite athletes during an international powerlifting competition. Baseline cortisol, DHEA and testosterone were determined in saliva samples in 19 (8 men, 11 women) junior and sub-junior athletes on the day before competition, and then on the competition day during the official weighing and in the hour after competition. Performance was determined by total output and the Wilks formula. No change in saliva steroid concentrations was observed between samples collected on the day before competition and the weighing samples. There was no gender effect on cortisol concentrations but saliva testosterone levels were always significantly higher in men than in women (p < 0.01), as was end-competition DHEA (p < 0.05). Cortisol and DHEA were significantly increased in male and female athletes after the competition (respectively, p < 0.01 and p < 0.05), whereas end-competition testosterone concentrations were only significantly increased in men (p < 0.01). Significant relationships were demonstrated between performance and end-competition cortisol levels in women and end-competition testosterone levels in men. These data indicate that workouts during an international powerlifting competition produce a significant increase in adrenal steroid hormones in both genders, with an increase in male gonadal steroid hormone. Further studies are necessary to examine the changes in oestradiol and progesterone in women and their potential impact on performance during international powerlifting competition. © 2012 Elsevier Inc. All rights reserved.


Guimard A.,University Paris - Sud | Vibarel-Rebot N.,University Paris - Sud | Prieur F.,University Paris - Sud | Baillot A.,University Paris - Sud | And 4 more authors.
Science and Sports | Year: 2013

Objective: The aim of this study was to determine the effects of obesity on the waking diurnal testosterone and dehydroepiandrosterone (DHEA) cycles in obese middle-aged male subjects. Methods: Saliva samples were collected at awakening and every 3 hours from 9:00 to 21:00. hours on 2 consecutive days in eight obese non-diabetic and eight healthy non-obese control men. Results: Saliva parameters showed day-to-day consistency, with an overall diurnal decline, except for testosterone in the obese group. Saliva testosterone concentrations were significantly lower (P< 0.05) at awakening, 9:00 and 12:00. hours in obese versus control subjects. No significant differences were observed in saliva DHEA concentrations between the obese and control subjects at any time of day. Conclusion: The results of this investigation indicate that obesity alone does not affect the concentrations or the diurnal pattern of DHEA in middle-aged men, whereas the diurnal pattern of testosterone appears altered in this population, with significantly lower values during the first part of the day. © 2013 Elsevier Masson SAS.


Vibarel-Rebot N.,University Paris - Sud | Rieth N.,University Paris - Sud | Lasne F.,AFLD | Jaffre C.,University of Rennes 2 – Upper Brittany | Collomp K.,University Paris - Sud
Contraception | Year: 2015

Background The impact of oral contraceptives (OCs) on the saliva diurnal pattern of metabolic steroid hormones remained unknown. Study design Saliva samples were taken from young healthy women (11 OC users, 10 non-OC users) to analyze cortisol, dehydroepiandrosterone (DHEA) and testosterone 4 times (days 1, 8, 15 and 22) over one menstrual cycle. Results OC use decreased saliva testosterone concentrations (p<.01) under all conditions of day and time, but not saliva cortisol. OC also decreased saliva DHEA concentrations during the first part of the day (p<.05), with a dampened amplitude in its diurnal pattern. Conclusion The clinical relevance requires further study. © 2015 Elsevier Inc. All rights reserved.


Zorgati H.,University Paris - Sud | Prieur F.,University Paris - Sud | Vergniaud T.,University Paris - Sud | Cottin F.,University Paris - Sud | And 6 more authors.
Steroids | Year: 2014

All systemically administered glucocorticoids (GC) are prohibited in-competition, because of the potential ergogenic effects. Although short-term GC intake has been shown to improve performance during submaximal exercise, literature on its impact during brief intense exercise appears to be very scant. The purpose of this study was to examine the ergogenic and metabolic effects of prednisone during repeated bouts of high-intensity exercise. In a double-blind randomized protocol, ten recreational male athletes followed two 1-week treatments (Cor: prednisone, 60 mg/day or Pla: placebo). At the end of each treatment, they hopped on their dominant leg for 30 s three times consecutively and then hopped until exhaustion, with intervals of 5 min of passive recovery. Blood and saliva samples were collected at rest and 3 min after each exercise bout to determine the lactate, interleukin-6, interleukin-10, TNF-alpha, DHEA and testosterone values. The absolute peak force of the dominant leg was significantly increased by Cor but only during the first 30-s hopping bout (p < 0.05), whereas time to exhaustion was not significantly changed after Cor treatment vs Pla (Pla: 119.9 ± 24.7; Cor: 123.1 ± 29.5 s). Cor intake lowered basal and end-exercise plasma interleukin-6 and saliva DHEA (p < 0.01) and increased interleukin-10 (p < 0.01), whereas no significant change was found in blood lactate and TNF-alpha or saliva testosterone between Pla and Cor. According to these data, short-term glucocorticoid intake did not improve endurance performance during repeated bouts of high-intensity exercise, despite the significant initial increase in absolute peak force and anti-inflammatory effect. © 2014 Elsevier Ltd. All rights reserved.


Le Panse B.,University of Orléans | Vibarel-Rebot N.,University of Orléans | Parage G.,International Powerlifting Federation | Albrings D.,International Powerlifting Federation | And 3 more authors.
Stress | Year: 2010

The purpose of this study was to examine salivary cortisol, dehydroepiandrosterone (DHEA), and testosterone responses to the bench press in an international powerlifting competition and to determine whether these salivary hormone concentrations could be used to predict performance. Twenty-six elite athletes (13 females and 13 males) provided saliva samples during the official weighing-in and after the last attempt at the bench press, as well as at baseline on a non-competition day. Performance index was determined with the Wilks formula, which adjusts powerlifting scores according to body mass. Salivary cortisol concentrations were significantly increased in all subjects after the bench press (p < 0.01), whereas DHEA concentrations were significantly increased in women (p < 0.01) but not in men after the bench press. No significant change in testosterone concentrations was observed during the experiment in either men or women, which resulted in a marked decrease in the testosterone/cortisol ratio. The performance index showed no significant correlation with any of the hormone responses to competition. In conclusion, despite the increase in stress adrenocortical hormone responses to an international powerlifting competition, these hormone concentrations alone are not predictors of bench press performance in elite powerlifting athletes. © 2010 Informa Healthcare USA, Inc.


Guimard A.,University of Orléans | Prieur F.,University of Orléans | Zorgati H.,University of Orléans | Morin D.,University of Orléans | And 2 more authors.
Journal of Strength and Conditioning Research | Year: 2014

Guimard, A, Prieur, F, Zorgati, H, Morin, D, Lasne, F, and Collomp, K. Acute apnea swimming: Metabolic responses and performance. J Strength Cond Res 28(4): 958-963, 2014- Competitive swimmers regularly perform apnea series with or without fins as part of their training, but the ergogenic and metabolic repercussions of acute and chronic apnea have not been examined. Therefore, we aimed to investigate the cardiovascular, lactate, arterial oxygen saturation and hormonal responses to acute apnea in relation to performance in male swimmers. According to a randomized protocol, 15 national or regional competitive swimmers were monitored while performing four 100-m freestyle trials, each consisting of four 25-m segments with departure every 30 seconds at maximal speed in the following conditions: with normal frequency breathing with fins (F) and without fins (S) and with complete apnea for the four 25-m segments with (FAp) and without fins (SAp). Heart rate (HR) was measured continuously and arterial oxygen saturation, blood, and saliva samples were assessed after 30 seconds, 3 minutes, and 10 minutes of recovery, respectively. Swimming performance was better with fins than without both with normal frequency breathing and apnea (p < 0.001). Apnea induced no change in lactatemia, but a decrease in arterial oxygen saturation in both SAp and FAp (p < 0.001) was noted and a decrease in HR and swimming performance in SAp (p < 0.01). During apnea without fins, performance alteration was correlated with bradycardia (r = 0.63) and arterial oxygen desaturation (r = -0.57). Saliva dehydroepiandrosterone was increased compared with basal values whatever the trial (p ≤ 0.05), whereas no change was found in saliva cortisol or testosterone. Further studies are necessary to clarify the fin effect on HR and performance during apnea swimming. © 2014 National Strength and Conditioning Association.

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