Acute endothelial response to testosterone gel administration in men with severe hypogonadism and its relationship to androgen receptor polymorphism: a pilot study

PURPOSE

Testosterone (T) exerts different effects on the cardiovascular system. Despite this knowledge, the acute vascular effect of androgen remains still poorly understood.

METHODS

We investigated the acute effects of T on vascular function in ten men (18-40 years age) with hypogonadism and severe hypotestosteronemia [serum total testosterone (TT) = 0.6 ± 0.3 ng/mL]. In a 4-day double-blind, randomized, placebo-controlled crossover study, we administered 80 mg daily dose of transdermal-T gel (TG) and evaluated endothelial variations with Endopat2000 (reactive hyperemia index, RHI and the augmentation index, AI); also, CAG repeat polymorphism in exon 1 of the androgen receptor gene was investigated.

RESULTS

After TG administration, RHI significantly improved at 4 h (p < 0.05), while AI improvement was recorded at 4 and 96 h, also when adjusted for heart rate (AI@75; p < 0.01 and p < 0.001, respectively). Direct relationships between ΔT, ΔDHT and ΔRHI variations (r = 0.37, p < 0.01; r = 0.17, p < 0.05, respectively) as well as between "CAG repeats" length and ΔLnRHI at 96 h (p < 0.03, r (2) = 0.47) were found. An inverse relationship between ΔT and ΔAI (p < 0.01, r = -0.35) and ΔAI@75 (p < 0.01, r = -0.38) were found.

CONCLUSION

Administration of TG causes an acute vasodilation and improves arterial stiffness probably due to non-genomic actions of T. Endothelial vasodilatory response was more pronounced depending on higher plasma TT and DHT levels attained. Clinical implications in elderly frail populations are discussed.

ICG angiography predicts burn scarring within 48 h of injury in a porcine vertical progression burn model

The current standard of care in determining the need to excise and graft a burn remains with the burn surgeon, whose clinical judgment is often variable. Prior work suggests that minimally invasive perfusion technologies are useful in burn prognostication. Here we test the predictive capabilities of Laser Doppler Imaging (LDI) and indocyanine green dye (ICG) angiography in the prediction of burn scarring 28 days after injury using a previously validated porcine burn model that shows vertical progression injury. Twelve female Yorkshire swine were burned using a 2.5 × 2.5 cm metal bar at variable temperature and application times to create distinct burn depths. Six animals (48 injuries total) each were analyzed with LDI or ICG angiography at 1, 24, 48, and 72 h following injury. A linear regression was then performed correlating perfusion measurements against wound contraction at 28 days after injury. ICG angiography showed a peak linear correlate (r(2)) of .63 (95% CI .34 to .92) at 48 h after burn. This was significantly different from the LDI linear regression (p < .05), which was measured at r(2) of .20 (95% CI .02 to .39). ICG angiography linear regression was superior to LDI at all timepoints. Findings suggest that ICG angiography may have significant potential in the prediction of long-term burn outcomes.

Immunohistochemistry for BRAF(V600E) antibody VE1 performed in core needle biopsy samples identifies mutated papillary thyroid cancers

BRAF(V600E) is the most frequent genetic mutation in papillary thyroid cancer (PTC) and has been reported as an independent predictor of poor prognosis of these patients. Current guidelines do not recommend the use of BRAF(V600E) mutational analysis on cytologic specimens from fine needle aspiration due to several reasons. Recently, immunohistochemistry using VE1, a mouse anti-human BRAF(V600E) antibody, has been reported as a highly reliable technique in detecting BRAF-mutated thyroid and nonthyroid cancers. The aim of this study was to test the reliability of VE1 immunohistochemistry on microhistologic samples from core needle biopsy (CNB) in identifying BRAF-mutated PTC. A series of 30 nodules (size ranging from 7 to 22 mm) from 30 patients who underwent surgery following CNB were included in the study. All these lesions had had inconclusive cytology. In all cases, both VE1 and BRAF(V600E) genotypes were evaluated. After surgery, final histology demonstrated 21 cancers and 9 benign lesions. CNB correctly diagnosed 20/20 PTC and 5/5 adenomatous nodules. One follicular thyroid cancer and 4 benign lesions were assessed at CNB as uncertain follicular neoplasm. VE1 immunohistochemistry revealed 8 mutated PTC and 22 negative cases. A 100% agreement was found when positive and negative VE1 results were compared with BRAF mutational status. These data are the first demonstration that VE1 immunohistochemistry performed on thyroid CNB samples perfectly matches with genetic analysis of BRAF status. Thus, VE1 antibody can be used on thyroid microhistologic specimens to detect BRAF(V600E)-mutated PTC before surgery.

Dry Eye Syndrome in Non-Exophthalmic Graves' Disease

BACKGROUND

The present study aims to assess qualitative and quantitative characteristics of tear film and corneal related impairment and to evaluate the quality of life in a cohort of non-exophthalmic Graves' disease (GD) patients.

METHODS

The series comprised 50 eyes from 25 newly diagnosed GD patients with no proptosis. As control group, 56 eyes of 28 thyroid disease-free subjects were enrolled.

RESULTS

The results of Schirmer I and II, break-up time, and Oxford scheme showed a significant difference between GD and controls. By ocular surface disease index (OSDI) questionnaire, eleven (44%) GD patients had normal ocular surface, while two (8%) had mild, four (16%) had moderate, and eight (32%) had severe dry eye. The mean score of the OSDI in the GD group was significantly (p < 0.001) higher with respect to the control group.

CONCLUSIONS

This study shows that the tear film and cornea are damaged in newly non-exophthalmic GD subjects.

Testosterone responses to standardized short-term sub-maximal and maximal endurance exercises: issues on the dynamic adaptive role of the hypothalamic-pituitary-testicular axis

BACKGROUND

Few and conflicting data on the acute adaptive role of the hypothalamic-pituitary-testicular (HPT) axis to sub-maximal endurance exercise exist.

AIMS

To investigate the acute HPT axis responses to standardized endurance exercises in a laboratory setting and the correlations between testosterone and classic adaptive hormones variations.

SUBJECTS AND METHODS

12 healthy male volunteers were recruited for this experimental study. Serum PRL, GH, ACTH, LH, cortisol, DHEAS, testosterone [total (TT), calculated free (cFT) and bioavailable (cBioT)], SHBG, and respective ratios, were evaluated before and after a 30-min sub-maximal exercise on cycle ergometer at individual anaerobic threshold (IAT) and a maximal exercise until exhaustion. Blood samples were collected before exercise (30, 15 min and immediately before), immediately after and at different time points during recovery (+15, +30 and +60 min) for hormones assays. Oxygen consumption and lactate concentration were evaluated.

RESULTS

Testosterone (TT, cFT and cBioT) acutely increased in all volunteers after both exercises. Testosterone increased in parallel to GH after both exercises and to cortisol only after maximal exercise. Differently from other increased hormones, testosterone increases were not correlated to exercise-intensity-related variables. The anabolic/catabolic steroids ratios were higher after sub-maximal exercise, compared to maximal.

CONCLUSIONS

A 30-min sub-maximal endurance exercise acutely increased serum testosterone similarly to maximal exercise, but without cortisol increases. Exercise-related testosterone peaks should be considered adaptive phenomena, but few data on their short- and long-term effects exist. Investigations on the mechanisms of adaptation to exercise in active individuals with physiological or pathological hypo-testosteronemia are warranted.

High sensitive thyroglobulin assay on thyroxine therapy: can it avoid stimulation test in low and high risk differentiated thyroid carcinoma patients?

Thyroglobulin (Tg) is a key marker in the follow-up of differentiated thyroid cancer (DTC). Diagnostic accuracy of serum Tg is higher after TSH stimulation than during thyroxine treatment. However, some studies suggest that TSH stimulation could be not necessary in a large part of patients, if Tg is measured by high sensitive assay under replacement therapy. The aim of this study was to evaluate the need of Tg stimulation test in DTC followed-up by sensitive Tg assay. In a prospective multicenter explorative study, 68 low or high risk patients underwent Tg measurement on thyroxine (ON-LT4-Tg) and after LT4 withdrawal (OFF-LT4-Tg). Undetectable ON-LT4-Tg and OFF-LT4-Tg values (i. e.,<0.15 ng/ml) were found in 56/68 patients, all with negative imaging workup. Twelve subjects had skewed OFF-LT4-Tg: 8 cases had increased ON-LT4-Tg and local recurrence (n=6), distant metastasis (n=1), or benign thyroglossal duct (n=1); the remaining 4 patients had undetectable ON-T4-Tg but detectable OFF-LT4-Tg and neck metastasis was recorded in one of these. By ROC analysis, the most accurate cutoff for ON-LT4-Tg and OFF-LT4-Tg were set at 0.23 ng/ml and 0.70 ng/ml, respectively. A positive ON-LT4-Tg value accurately predicts a positive stimulation test and confers an Odds Ratio of 464 (95% CI from 26.3 to 8 173.2, p<0.0001) to have persistent/recurrent disease. This study shows that DTC patients with ON-LT4-Tg below 0.23 ng/ml by our high sensitive assay should be considered disease free and they can avoid Tg stimulation test. High sensitive Tg assays should be used to better manage DTC patients.

Medullary thyroid nodules by measurement of calcitonin (Ct) in aspiration needle washout in patients with multinodular goiter and moderately elevated serum Ct

The accuracy of fine needle aspiration cytology (FNAC) is low in medullary thyroid carcinomas (MTC). Recently, a few papers analyzed the measurement of calcitonin (Ct) in washout of the needle after aspiration (WO-Ct) suggesting that this approach may be useful in patients with high serum Ct. Here we reported, for the first time in our best knowledge, 3 patients with multinodular goiter, moderately elevated serum Ct, high value of WO-Ct, and medullary outcome. These findings suggest that in presence of high serum Ct, FNAC should be performed in all nodules, and it should be combined with WO-Ct in all cases.

Does normal thyroid gland by ultrasonography match with normal serum thyroid hormones and negative thyroid antibodies?

Few papers have shown that a hypoechoic appearance of the thyroid gland at ultrasonography (US) is related to a hypofunction and serum positivity of thyroid antibodies (T-Ab). However, it is not ascertained if normal thyroid appearance at US correspond to normal thyroid laboratory tests. The aim of this study was to assess the value of normal thyroid at US in predicting normal thyroid hormones and negative T-Ab in a cohort of 48 adult patients. All patients (37 females and 11 males) were referred to our hospital to undergo their first thyroid US examination, followed by a thyroid function evaluation. All subjects had normal thyroid gland at US. As a control group 65 patients with hypoechoic and inhomogeneous thyroid gland were enrolled. All 48 patients had normal free-T (3) and free-T (4) levels. While 41 patients (85.4%) showed normal TSH, in 7 subjects (14.6%) TSH was elevated and a significant (p < 0.001) difference was recorded between the two groups in mean TSH value. Positive T-Ab value was found in 5 patients (10.4%) and the remaining 43 patients (89.6%) had negative T-Ab. TSH was not significantly correlated with age, thyroid volume or BMI. The multivariate model showed that only BMI was significantly correlated to thyroid volume (p < 0.01, r(2)=0.31). These results showed that normal thyroid recorded by US matches with normal thyroid laboratory assessment to a large degree. These preliminary data need to be confirmed in a prospective study and in a larger series and should suggest the evaluation of thyrotropin and thyroid antibodies in subjects with normal thyroid gland as assessed by US.

Subclinical hyperthyroidism and sport eligibility: an exploratory study on cardiovascular pre-participation screening in subjects treated with levothyroxine for multinodular goiter

BACKGROUND

Subclinical hyperthyroidism (sHT) affects cardiovascular (CV) morphology and function; whether such changes can impact on sport eligibility is unclear.

AIM

This exploratory study evaluated the CV system and sport eligibility in athletes with levothyroxine-induced sHT, in the setting of mandatory pre-participation screening.

SUBJECTS AND METHODS

A full, non-invasive CV screening (history and physical examination, 12-lead ECG, echocardiography, 24-hour Holter ECG, exercise stress test) was performed in two groups of untrained female athletes affected by non-toxic multinodular goiter. One group was taking levothyroxine at mildly suppressive doses (TG) whereas the other was untreated (UG). There was also a group of healthy controls (HC).

RESULTS

In TG the following characteristics were observed: a) a higher resting heart rate (HR; p<0.01 and p<0.05, vs HC and UG respectively), b) a thicker left ventricular posterior wall (p<0.05 vs HC, and p<0.05 vs HC and UG, respectively), c) a higher mean HR during the 24-hour Holter ECG (p<0.01 and p<0.05, vs HC and UG respectively), and d) a lower achieved maximum work load (p<0.05, vs HC). No differences in the prevalence of cardiac arrhythmias among groups were observed. Sport eligibility was granted to all except one subject in the TG.

CONCLUSIONS

Although some alterations were found in athletes with levothyroxine-induced mild sHT, these are probably of limited clinical relevance and they did not contraindicate sport participation in the majority of cases. Future research to address both health risks and the need for specific evaluations (e.g. free thyroxine, TSH, echocardiography) during the preparticipation screening of athletes with sHT is warranted.

Urinary and serum hormones profiles after testosterone enanthate administration in male hypogonadism: concerns on the detection of doping with testosterone in treated hypogonadal athletes

OBJECTIVE

To describe serum and urinary hormones, androgens metabolites and testosterone/epitestosterone ratio profiles after testosterone administration in male hypogonadal volunteers, and to evaluate their possible usefulness in detecting doping with testosterone in treated hypogonadal athletes.

DESIGN

Controlled open label design vs placebo; pharmacokinetic study.

PARTICIPANTS

Ten male volunteers affected by severe hypogonadism (serum testosterone <2.31 ng/ml).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Serum and urinary parameters were evaluated, by radioimmunoassay and gas chromatography-mass spectrometry, before and at different time points for 7/3 weeks after a single administration of testosterone enanthate (250 mg) or placebo, respectively.

RESULTS

As partially known, testosterone administration increased, with great individual variability, urinary concentrations of glucuronide testosterone, androsterone, etiocholanolone, 5alpha-androstane- 3alpha,17beta-diol, 5beta-androstane-3alpha,17beta-diol, testosterone/ epitestosterone and testosterone/LH ratios; and decreased epitestosterone and 5alpha-androstane-3beta,17beta-diol/5beta-androstane- 3alpha,17beta-diol ratio. Serum testosterone and dihydrotestosterone increased in all volunteers, and concentrations higher than the upper reference limits were observed in many volunteers until 2 weeks after testosterone administration.

CONCLUSION

Whereas the observed prolonged hyperandrogenism partially limited data interpretation, the report ed characteristics of variation of urinary parameters might be used to suspect testosterone misuse in hypogonadal athletes treated with testosterone enanthate. In this sense, while the actual threshold for tes tos terone/epites tos ter one ratio was confirmed to be of reduced usefulness, we suggest a contemporary evaluation of whole urinary androgen metabolites profile and serum androgens, at specific time points after testosterone enanthate administration. Moreover, an adequate tailoring of treatment, to avoid transitory hyperandrogenism, is highly advisable. Further studies on strategies for detecting doping with testosterone in hypogonadal athletes are warranted.

Efficacy of wrists overnight compression (HT 7 point) on insomniacs: possible role of melatonin?

AIM

Insomnia is a major problem which decreases life quality. Many causes are involved with it and anxiety is often associated. The underlying mechanism is not completely understood, even though different factors seem to be associated. Among them melatonin and its circadian rhythm is thought to have an important role. In addition, acupressure and acupuncture are known to ameliorate insomnia and anxiety, when a specific wrist point is stimulated (HT 7 Shenmen). With these bases, the aim of the present study has been to evaluate the efficacy of an acupressure device, ''H7-insomnia control'', positioned on HT 7 points, during the night, in terms of general health and anxiety levels, together with the evaluation of sleep quality and the urinary melatonin metabolite 6-hydroxymelatonin sulphate determination, in a number of insomniacs.

METHODS

Forty patients with insomnia were divided into two groups and randomly received either the H7 or placebo treatments, in a double-blind protocol, for 20 nights. Before and after treatments every subject answered a series of questionnaires (General Health Questionnaire 28 items; State-Trait Anxiety Inventory; Pittsburgh Sleep Quality Index) and collected 24 h urines, divided into two samples of 12 h each. Urinary melatonin metabolite was then determined using a RIA method.

RESULTS

Data obtained indicate that the device H7-insomnia control is efficacious to ameliorate quality of sleep and reduce anxiety levels in insomniacs, at a higher extent than in the placebo group. In addition, the 24 hours urinary melatonin metabolite rhythm, obtained at the end of treatment, was considered as being normal in a higher percentage of H7-treated patients, with respect to the placebo group.

CONCLUSION

It is plausible to hypothesize that the wrist acupressure device might be considered a valid tool, without adverse effects since it does not contain pharmaceutical products, that is able to naturally ameliorate sleep quality in insomniacs, acting through a not jet completely clarified mechanism, that may involve melatonin.

The Long-Acting Phosphodiesterase Inhibitor Tadalafil does not Influence Athletes' V·O2max, Aerobic, and Anaerobic Thresholds in Normoxia

Whereas experimental studies showed that in healthy trained subjects, the phosphodiesterase-5 inhibitor (PDE-5i) sildenafil improves exercise capacity in hypoxia and not in normoxia, no studies on the effects of the long half-life PDE-5i tadalafil exist. In order to evaluate whether tadalafil influences functional parameters and performance during a maximal exercise test in normoxia, we studied 14 healthy male athletes in a double-blind cross-over protocol. Each athlete performed two tests on a cycle ergometer, both after placebo or tadalafil (at therapeutic dose: 20 mg) administration. Oxygen consumption (VO2), blood lactate, respiratory exchange ratio, rate of perceived exertion, arterial blood pressure (BP), heart frequency (HR) and oxygen pulse (VO2/HR) were evaluated before exercise, at individual ventilatory and anaerobic thresholds (IVT and IAT), at VO2max and during recovery. Compared to placebo, a single tadalafil administration significantly reduced systolic BP before and after exercise (p < 0.05), decreased VO2/HR at IVT (13.3 +/- 1.8 vs. 14.5 +/- 2.1 mL . beat (-1); p = 0.03), but did not modify individual VO2max, IVT, or IAT. In healthy athletes, 20 mg of tadalafil does not substantially influence physical fitness-related parameters, exercise tolerance, and cardiopulmonary responses to maximal exercise in normoxia; it remains to be verified if higher doses/prolonged use influence health and/or sport performance in field conditions.

Do non-steroidal anti-inflammatory drugs influence the steroid hormone milieu in male athletes?

Prostaglandins modulate the hypothalamus-pituitary-adrenal and -gonadal axis pathways. We explored the effects of a single course of treatment with acetylsalicylic acid (ASA), an inhibitor of prostaglandin synthesis, on the steroid milieu in athletes. Morning plasma cortisol (F), dehydroepiandrosterone sulphate, free-testosterone, testosterone (T) and their ratios were evaluated before and after the administration of either ASA or placebo in twelve male athletes, when affected by minor musculoskeletal trauma and, as control, after a five/six week wash-out in healthy conditions respectively. One tablet of ASA (800 mg), or placebo, was administered two times daily for 10 days during treatment. All the volunteers suspended exercise training during treatment. The results revealed that compared to placebo, plasma F was significantly lower after ASA treatment (p = 0.023). Furthermore, the comparison of hormone's absolute and percentage of variations (Delta and Delta%) between ASA and placebo treatment showed significant differences respectively for DeltaF (p = 0.045), for DeltaT (p = 0.047), for DeltaT/F (p = 0.042), for DeltaF% (p = 0.04) and for DeltaT% (p = 0.049). Our data suggest that in comparison to placebo, a short-term ASA treatment is able to influence the plasma steroid milieu in athletes. Due to the observed variability of the individual hormonal patterns, further research is required to substantiate these findings.

Cortisol, dehydroepiandrosterone sulphate and dehydroepiandrosterone sulphate/cortisol ratio responses to physical stress in males are influenced by pubertal development

To evaluate the influence of chronological age and pubertal development on the hypothalamus-pituitary-adrenal (HPA) axis response to stress, we studied the possible correlations between male pubertal characteristics and salivary cortisol (C), DHEAS and the DHEAS/C ratio before (pre-stress) and after acute exercise-stress in young male volunteers (no. 87; 13.3+/-2.1 yr). In our overall study population, the mean pre-stress salivary C and DHEAS concentrations, significantly increased after exercise-related stress, whereas the DHEAS/C ratio significantly decreased. Pre-stress salivary C was positively correlated with chronological age, and after-stress salivary C concentration variations were negatively correlated with pubertal stage, mean testis volume and pre-stress salivary DHEAS. Furthermore, salivary DHEAS concentrations and the DHEAS/C ratio, before and after exercise stress, were positively correlated with chronological age, pubertal stage, pre-stress salivary testosterone (T), testis volume and body mass index (BMI). In contrast with late pubertal stages (P4, P5), young individuals at early stages of puberty (P1 to P3) showed higher C increase and lower DHEAS/C ratio after exercise-related stress. In conclusion, since C is also a mediator of stress-related negative effects on health and the DHEAS/C ratio has been hypothesized as an index for the degree to which an individual is buffered against the negative effects of stress, these data might suggest potentially increased stress-related risks at early stages of male puberty.

Salivary Steroids at Rest and After a Training Load in Young Male Athletes: Relationship with Chronological Age and Pubertal Development

Puberty influences both the performance and the hormonal responses to exercise-related stress. We evaluated the distribution and the correlation between pubertal characteristics and the salivary cortisol (sC) and testosterone (sT) responses to acute physical exercise in young male athletes (13.4 +/- 2.1 yr, n = 110). The mean pre-exercise nmol . L (-1) sC and sT concentrations were 19.08 +/- 4.32 and 0.34 +/- 0.15 and increased to 21.27 +/- 5.51 and 0.41 +/- 0.16 after a 90-min training session (p < 0.01). The sC concentration at rest was positively correlated with chronological age (p < 0.01) and negatively correlated with fat % (p < 0.05), whereas significant negative correlations of DeltasC and DeltasC% after exercise with age, pubertal stage and mean testis volume (p < 0.05) were observed. The sT increase after exercise was correlated with chronological age, pubertal stage and pre-exercise sT levels (p < 0.01), whereas the DeltasT and DeltasT% of increase were negatively correlated with chronological age and resting sT levels (p < 0.05 and p < 0.01). In the present study, we observed the presence of high inter-individual variability of different biological parameters (anthropometry, pubertal stage, hormones, etc.) within athletes selected by chronological age in the same class and the presence of significant correlations between chronological age, puberty and the steroid hormone responses to physical exercise. Our data suggest the need for different criteria in exercise prescription and selection of young athletes and in the evaluation of stress reactivity at puberty.

The laboratory assessment of partial androgen deficiency of the aging male

The diagnosis of andropause, currently named partial androgen deficiency of the aging male (PADAM), by the International Society for the Study of Aging Male (ISSAM), is based on the presence of clinical symptoms together with a biochemical evidence of hypogonadism. Thus, the definition of specific diagnostic criteria, both as clinical manifestations and laboratory findings, is fundamental to identify those men for whom androgen replacement therapy should be warranted. Clinical manifestations suspected to be caused by androgen deficiency are numerous (decreased libido and erectile dysfunction, decreased muscle mass and strength, decreased bone mineral density, increased fat mass, depression, fatigue, irritability, etc) and, for these, the linkage to a real hypogonadal state must be confirmed on an individual basis. In this regard, the exact list of reproductive hormones to be evaluated, for screening or for diagnosis confirmation, together with eventual dynamic endocrine test (GnRH, hCG, clomiphene, etc) must be adjusted. Furthermore, the clinician must be aware of the methods and limits of androgen assays in order to be able to specifically select, where possible, those which are validated by comparison to a "gold standard" or accepted method of measurement.

Androgenic-anabolic steroids abuse in males

Androgenic-anabolic steroids (AAS) is an official definition for all male sex steroid hormones, their synthetic derivatives and their active metabolites. AAS are drugs with specific therapeutic indications, yet they are popularly known because of their worldwide non-therapeutic use in a large number of healthy individuals. Doping with AAS has become so widespread in athletics that it affects the outcome of sports contests. Furthermore, AAS non-therapeutic use is increasing particularly among adolescents and females, becoming one of the main causes of iatrogenic diseases due to drug abuse. All physicians must be aware about the large diffusion and side effects related to AAS non-therapeutic use, in order to discover clinical signs of AAS abuse and/or to start adequate preventive and/or therapeutic actions.

Heredity and Pituitary Response to Exercise-Related Stress in Trained Men

To evaluate the role of heredity in the pituitary responses to exercise-related stress, serum ACTH, beta-endorphin, cortisol, GH, and PRL responses to a thirty-minute treadmill exercise at individual anaerobic threshold were evaluated in nine pairs of male monozygotic twin athletes. Hormone evaluations were performed before (-30, -15, 0 pre) and after exercise (0 post, + 15, + 30, + 45, + 60, and + 90 min). The intraclass correlation coefficient (expression of within-pair resemblance) was computed for each hormone before and after exercise as area under curves (AUC), absolute values, and percentage of variation, respectively. The exercise-related stress condition induced a significant increase for all evaluated hormones before (anticipatory response) and/or after exercise. As new data, we observed: 1) A significant within-pair resemblance for exercise-related GH and PRL increase (AUCs and/or absolute values), and for the percentage of variation of cortisol, and 2) the lack of significant resemblance for the observed increase of ACTH, cortisol and absolute beta-endorphin serum concentration. This first co-twin control study supports the hypothesis that, in trained men, there are probably different relative roles for the influence of genetic factors on the pituitary hormones involved in physiological adaptation to exercise-related stress. Furthermore, our findings justify further investigations into this topic.

Physical stress and qualitative gonadotropin secretion: LH biological activity at rest and after exercise in trained and untrained men

Sports influence the hypothalamus-pituitary-gonadal axis (HPG). The purpose of this study was to analyze the effects of physical stress on qualitative male LH secretion. We evaluated the HPG axis at rest and the LH response to a treadmill exercise (90 % of Vdot;O 2 max) in eight trained (running 50 to 70 km/week) and eight untrained subjects. FSH, total testosterone (T) and free testosterone (FT) were evaluated at rest by radioimmunoassay, whereas serum LH was evaluated both by radioimmunoassay (I-LH) and by a biological assay (RICT, B-LH), before (-30, -15, 0 pre) and after exercise (0 post, + 15, + 30, + 60 min). Semen analysis was performed. The results showed that the B/I LH ratio was significantly lower at rest in athletes than in controls (1.3 +/- 0.5 and 2.1 +/- 0.7 respectively, p < 0.05) and the B-LH and B/I LH ratio were reduced after exercise in controls (from 21.1 +/- 5.7 to 13.9 +/- 3.4 mIU/mL and from 2.3 +/- 0.8 to 1.6 +/- 0.4, at + 60 respectively, p < 0.05). T and FT were significantly lower in athletes compared with controls (4.18 +/- 1.1 vs 5.96 +/- 1.6 ng/ml and 24.3 +/- 4.8 vs 29.7 +/- 5.2 pg/ml respectively, p < 0.05). Semen parameters showed no difference. The B/I LH ratio could be a "marker" of altered LHRH secretion due to an exercise-linked adaptive condition.