Complementary information concerning the suspected interindividual transmission of GW1516, a substance prohibited in sport, through intimate contact: a case report.

PURPOSE: Inadvertent and/or unknowing exposure to drugs and drug residues has been frequently debated in situations of so-called adverse analytical finding (AAF) in the context of sports drug testing programs. Transfer of drug residues via unprotected intercourse is a conceivable scenario but scientific data and authentic case reports are scarce. Herein, investigations into two AAFs with the peroxisome proliferator-activated receptor delta (PPARδ) agonist GW1516 are reported and discussed. METHODS: To probe for a contamination scenario involving sexual intercourse, two assays were used to determine semenogelin in human urine, with one employing an immunochromatographic lateral flow approach and another based on liquid chromatography-tandem mass spectrometry. Further, drug-residue testing using patients' ejaculate was conducted by utilizing liquid chromatography in conjunction with a triple quadrupole mass spectrometer, followed by re-analysis of suspect samples (i.e., samples indicating the presence of relevant compounds) using high resolution/high mass accuracy mass spectrometry. RESULTS: In one case, but not the other, the possibility of intimate contact as the source of the AAF was confirmed after a thorough investigation of potential contamination scenarios. Subsequent research revealed analytical evidence for the presence of seminal fluid in one of the female athlete's doping control urine samples, and the analysis of clinical ejaculate specimens provided first data on an authentic concentration level of GW1516 and its metabolites in human seminal fluid. CONCLUSIONS: The combined facts substantiate the possibility of an AAF caused by unprotected sexual intercourse and the plausibility of the case-related arguments.

[Prevalence of metatarsal growth plate lesions in Swiss fattening bulls]. / Prävalenz von osteochondrotischen Veränderungen in den Epiphysenfugen der Ossa metatarsalia bei Schweizer Maststieren.

INTRODUCTION: The prevalence of osteochondral changes in the metatarsal growth plates of fattening bulls was investigated. Plantarodorsal radiographic views of the metatarsal region of 204 hind legs from 102 slaughtered fattening bulls were taken. Radiographic lesions in metatarsal growth plates were confirmed in selected cases using computed tomography (n=14) and histology (n=6). Radiographic criteria for growth plate lesions were axis deviations between the metatarsal bones and the digit, radiolucencies in the growth plate, increased bone density in the metaphysis, irregularities of the growth plate and marginal osteophytes («lipping¼). The individual lesions were categorised as present/absent or 1 = slight, 2 = distinct, and 3 = severe. A weighted sum of these radiographic changes was generated for each growth plate and for each animal, and used for statistical analysis of the associations between husbandry factors and the occurrence of lesions. Almost all of the metatarsal bones had signs of osteochondral changes on the radiographs of the growth plates. The most common lesions were lipping (99,5 %), increased bone density in the metaphysis (66,6 %) and radiolucencies in the growth plates (64,1 %). Computed tomography and histology revealed hyperplasia of the margins of the epiphysis and metaphysis, focal increase in bone deposits accompanied by incomplete ossification and irregular and widened cartilage columns of the growth plate. There were statistically significant associations between the weighted radiographic changes and slaughter weight, average daily weight gain, husbandry practices and production label. The prevalence of radiographic lesions indicative for osteochondrosis of the metatarsal growth plates of fattening bulls slaughtered at a local abattoir was high. The extent to which the distinct and severe lesions are associated with reduced production and obvious clinical lameness requires further study.

INTRODUCTION: La prévalence des modifications ostéochondrales des plaques de croissance métatarsiennes des taureaux à l'engraissement a été étudiée. Des radiographies planto-dorsales de la région métatarsienne de 204 membres postérieurs de 102 taureaux d'engraissement abattus ont été réalisées. Les lésions radiographiques des plaques de croissance métatarsiennes ont été confirmées dans des cas sélectionnés par tomodensitométrie (n=14) et histologie (n=6). Les critères radiographiques des lésions du cartilage de conjugaison étaient les déviations de l'axe entre les os métatarsiens et les phalanges, les radiotransparences du cartilage de conjugaison, l'augmentation de la densité osseuse de la métaphyse, les irrégularités du cartilage de conjugaison et les ostéophytes marginaux (« lipping ¼). Les lésions individuelles ont été classées comme présentes/absentes ou 1 = légères, 2 = distinctes et 3 = sévères. Une somme pondérée de ces modifications radiographiques a été générée pour chaque plaque de croissance et pour chaque animal et utilisée pour l'analyse statistique des associations entre les facteurs d'élevage et l'apparition de lésions. Presque tous les os métatarsiens présentaient des signes de modifications ostéochondrales sur les radiographies des plaques de croissance. Les lésions les plus fréquentes étaient le « lipping ¼ (99,5 %), l'augmentation de la densité osseuse au niveau de la métaphyse (66,6 %) et les radiotransparences des plaques de croissance (64,1 %). La tomodensitométrie et l'histologie ont révélé une hyperplasie des marges de l'épiphyse et de la métaphyse, une augmentation focale des dépôts osseux accompagnée d'une ossification incomplète et des colonnes cartilagineuses irrégulières et élargies sur le cartilage de conjugaison. Il y avait des associations statistiquement significatives entre les changements radiographiques pondérés et le poids d'abattage, le gain de poids quotidien moyen, les pratiques d'élevage et les labels de production. La prévalence des lésions radiographiques révélatrices d'une ostéochondrose des plaques de croissance métatarsiennes des taureaux d'engraissement abattus dans un abattoir local était élevée. La mesure dans laquelle ces lésions distinctes et sévères sont associées à une production réduite et à une boiterie clinique évidente nécessite une étude plus approfondie.

[Equine dentistry: Survey on Swiss horse owners]. / Zahnbehandlungen beim Pferd: Umfrage bei Pferdebesitzern in der Schweiz.

INTRODUCTION: The interest in equine dentistry has significantly increased in the last 15 years. On the part of the veterinarians as well as of the horse owners there is a strong attention to the topic. The aim of the questionnaire was to investigate amongst horse owners what their level of information and preferences about dental treatment are and how they are implemented. The questionnaire was translated into the three national languages and included 20 questions about level and sources of information, frequency of treatments and the horse owner's stance over sedation of the animals. With a return rate of 45% (1'466 of 3'250 sent questionnaires) significant conclusions could be drawn. Horse owners showed a strong demand for clarification regarding tooth problems, the causes, consequences and methods of treatment. More than half of the owners considered themselves not well informed. The treating person was in 66.7% a veterinarian with a special education. Horse owners indicated that information circulated most frequently by word of mouth recommendations and they explicitly wished information from professional and reliable sources. The questionnaire provided a clear result about current equine dental treatments. We suggest that they should be performed by veterinarians only with a special education.

INTRODUCTION: Au cours des 15 dernières années, l'intérêt pour la médecine dentaire chez les chevaux a de nouveau beaucoup augmenté. Tant les vétérinaires que les propriétaires de chevaux accordent une grande importance à ce sujet. Le but de la présente enquête était de juger le niveau d'information et des préférences en matière de soins dentaires parmi les propriétaires en Suisse et comment elles se concrétisent. Le questionnaire a été rédigé dans les trois langues nationales et comportait 20 questions relatives au niveau et aux sources d'information des propriétaires ainsi qu'à la fréquence des soins dentaires et à la position des propriétaires face à la sédation de leur animal. Avec un taux de retour de 45% (1'466 sur 3'250 questionnaires envoyés), il a été possible de tirer des conclusions significatives. Les propriétaires de chevaux montrent un net besoin en matière d'explication concernant les problèmes dentaires, leurs causes, leurs conséquences et leurs méthodes de traitement. Plus de la moitié se considèrent comme insuffisamment informés. Chez 66.7%, le traitement est effectué par un vétérinaire spécialisé en soins dentaires. Les propriétaires déclarent que les informations leur sont le plus souvent fournies oralement et souhaitent clairement des informations de sources professionnelles et fiables. L'enquête a fourni des données claires sur les soins dentaires actuels chez le cheval. Il en résulte que nous recommandons que ces soins soient effectués principalement par des vétérinaires spécialisés sur ce domaine.

Synthesis, characterization, and detection of new oxandrolone metabolites as long-term markers in sports drug testing.

The discovery and implementation of the long-term metabolite of metandienone, namely 17ß-hydroxymethyl-17α-methyl-18-norandrost-1,4,13-trien-3-one, to doping control resulted in hundreds of positive metandienone findings worldwide and impressively demonstrated that prolonged detection periods significantly increase the effectiveness of sports drug testing. For oxandrolone and other 17-methyl steroids, analogs of this metabolite have already been described, but comprehensive characterization and pharmacokinetic data are still missing. In this report, the synthesis of the two epimeric oxandrolone metabolites-17ß-hydroxymethyl-17α-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one and 17α-hydroxymethyl-17ß-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one-using a fungus (Cunninghamella elegans) based protocol is presented. The reference material was fully characterized by liquid chromatography nuclear magnetic resonance spectroscopy and high resolution/high accuracy mass spectrometry. To ensure a specific and sensitive detection in athlete's urine, different analytical approaches were followed, such as liquid chromatography-tandem mass spectrometry (QqQ and Q-Orbitrap) and gas chromatography-tandem mass spectrometry, in order to detect and identify the new target analytes. The applied methods have demonstrated good specificity and no significant matrix interferences. Linearity (R(2) > 0.99) was tested, and precise results were obtained for the detection of the analytes (coefficient of variation <20%). Limits of detection (S/N) for confirmatory and screening analysis were estimated at 1 and 2 ng/mL of urine, respectively. The assay was applied to oxandrolone post-administration samples to obtain data on the excretion of the different oxandrolone metabolites. The studied specimens demonstrated significantly longer detection periods (up to 18 days) for the new oxandrolone metabolites compared to commonly targeted metabolites such as epioxandrolone or 18-nor-oxandrolone, presenting a promising approach to improve the fight against doping.

Extension and customization of self-stability control in compliant legged systems.

Several recent studies on the control of legged locomotion in animal and robot running focus on the influence of different leg parameters on gait stability. In a preceding investigation self-stability controls showing deadbeat behavior could be obtained by studying the dynamics of the system in dependence of the leg orientation carefully adjusted during the flight phase. Such controls allow to accommodate disturbances of the ground level without having to detect them. Here we further this method in two ways. Besides the leg orientation, we allow changes in leg stiffness during flight and show that this extension substantially improves the rejection of ground disturbances. In a human like example the tolerance of random variation in ground level over many steps increased from 3.5% to 35% of leg length. In single steps changes of about 70% leg length (either up or down) could be negotiated. The variable leg stiffness not only allows to start with flat leg orientations maximizing step tolerances but also increase the control subspace. This allows to customize self-stability controls and to consider physical and technical limitations found in animals and robots.

New potential markers for the detection of boldenone misuse.

Boldenone is one of the most frequently detected anabolic androgenic steroids in doping control analysis. Boldenone misuse is commonly detected by the identification of the active drug and its main metabolite, 5ß-androst-1-en-17ß-ol-3-one (BM1), by gas chromatography-mass spectrometry (GC-MS), after previous hydrolysis with ß-glucuronidase enzymes, extraction and derivatization steps. However, some cases of endogenous boldenone and BM1 have been reported. Nowadays, when these compounds are detected in urine at low concentrations, isotope ratio mass spectrometry (IRMS) analysis is needed to confirm their exogenous origin. The aim of the present study was to identify boldenone metabolites conjugated with sulphate and to evaluate their potential to improve the detection of boldenone misuse in sports. Boldenone was administered to a healthy volunteer and urine samples were collected up to 56h after administration. After a liquid-liquid extraction with ethyl acetate, urine extracts were analysed by liquid chromatography tandem mass spectrometry (LC-MS/MS) using electrospray ionisation in negative mode by monitoring the transition of m/z 365-350, specific for boldenone sulphate. Boldenone sulphate was identified in the excretion study urine samples and, moreover, another peak with the same transition was observed. Based on the MS/MS behaviour the metabolite was identified as epiboldenone sulphate. The identity was confirmed by isolation of the LC peak, solvolysis and comparison of the retention time and MS/MS spectra with an epiboldenone standard. These sulphated metabolites have not been previously reported in humans and although they account for less than 1% of the administered dose, they were still present in urine when the concentrations of the major metabolites, boldenone and BM1, were at the level of endogenous origin. The sulphated metabolites were also detected in 10 urine samples tested positive to boldenone and BM1 by GC-MS. In order to verify the usefulness of these new metabolites to discriminate between endogenous and exogenous origin of boldenone, four samples containing endogenous boldenone and BM1, confirmed by IRMS, were analysed. In 3 of the 4 samples, neither boldenone sulphate nor epiboldenone sulphate were detected, confirming that these metabolites were mainly detected after exogenous administration of boldenone. In contrast, boldenone sulphate and, in some cases, epiboldenone sulphate were present in samples with low concentrations of exogenous boldenone and BM1. Thus, boldenone and epiboldenone sulphates are additional markers for the exogenous origin of boldenone and they can be used to reduce the number of samples to be analysed by IRMS. In samples with boldenone and BM1 at the concentrations suspicion for endogenous origin, only if boldenone and epiboldenone sulphates are present, further analysis by IRMS will be needed to confirm exogenous origin.

Clenbuterol - regional food contamination a possible source for inadvertent doping in sports.

The misuse of the sympathomimetic and anabolic agent clenbuterol has been frequently reported in professional sport and in the livestock industry. In 2010, a team of athletes returned from competition in China and regular doping control samples were taken within the next two days. All urine samples contained low amounts (pg/ml) of clenbuterol, drawing the attention to a well-known problem: the possibility of an unintended clenbuterol intake with food. A warning that Chinese meat is possibly contaminated with prohibited substances according to international anti-doping regulations was also given by Chinese officials just before the Bejing Olympic Games in 2008. To investigate if clenbuterol can be found in human urine, a study was initiated comprising 28 volunteers collecting urine samples after their return from China. For the quantification of clenbuterol at a low pg/ml level, a very sensitive and specific isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed using liquid/liquid re-extraction for clean-up with a limit of detection and quantification of 1 and 3 pg/ml, respectively. The method was validated demonstrating good precision (intra-day: 2.9-5.5 %; inter-day: 5.1-8.8%), accuracy (89.5-102.5%) and mean recovery (81.4%). Clenbuterol was detectable in 22 (79%) of the analyzed samples, indicating a general food contamination problem despite an official clenbuterol prohibition in China for livestock.

High-throughput screening for various classes of doping agents using a new 'dilute-and-shoot' liquid chromatography-tandem mass spectrometry multi-target approach.

A new multi-target approach based on liquid chromatography--electrospray ionization tandem mass spectrometry (LC-(ESI)-MS/MS) is presented to screen for various classes of prohibited substances using direct injection of urine specimens. With a highly sensitive new generation hybrid mass spectrometer classic groups of drugs--for example, diuretics, beta2-agonists--stimulants and narcotics are detectable at concentration levels far below the required limits. Additionally, more challenging and various new target compounds could be implemented. Model compounds of stimulant conjugates were studied to investigate a possible screening without complex sample preparation. As a main achievement, the integration of the plasma volume expanders dextran and hydroxyethyl starch (HES), commonly analyzed in time-consuming, stand-alone procedures, is accomplished. To screen for relatively new prohibited compounds, a common metabolite of the selective androgen receptor modulator (SARMs) andarine, a metabolite of growth hormone releasing peptide (GHRP-2), and 5-amino-4-imidazolecarboxyamide ribonucleoside (AICAR) are analyzed. Following a completely new approach, conjugates of di(2-ethylhexyl) phthalate (DEHP) metabolites are monitored to detect abnormally high levels of plasticizers indicating for illicit blood transfusion. The assay was fully validated for qualitative purposes considering the parameters specificity, intra- (3.2-16.6%) and inter-day precision (0.4-19.9%) at low, medium and high concentration, robustness, limit of detection (1-70 ng/ml, dextran: 30 µg/ml, HES: 10 µg/ml) and ion suppression/enhancement effects. The analyses of post-administration and routine doping control samples demonstrates the applicability of the method for sports drug testing. This straightforward and reliable approach accomplishes the combination of different screening procedures resulting in a high-throughput method that increases the efficiency of the labs daily work.

Di(2-ethylhexyl) phthalate metabolites as markers for blood transfusion in doping control: intra-individual variability of urinary concentrations.

To indicate homologous or autologous blood transfusion in sports drug testing, quantification of increased urinary concentrations of di(2-ethylhexyl) phthalate (DEHP) metabolites presents a promising approach; however, the possible intra-individual variation of the metabolite concentrations over time has not been well characterized. The aim of this study was to explore the intra-individual variability of urinary DEHP metabolites among seven volunteers without special occupational exposure to DEHP during one week (n = 253) in order to investigate the possibility of increased urinary concentrations of the metabolites caused by, for example, residential, dietary, or environmental exposure. Quantification of three DEHP metabolites--mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate, and mono(2-ethyl-5-hydroxyhexyl) phthalate--was accomplished after enzymatic hydrolysis of urinary glucuronide conjugates and direct injection using isotope-dilution liquid chromatography-tandem mass spectrometry. Although urinary concentrations of DEHP metabolites showed considerable intra-individual variation, no increased values were observed comparable to the concentrations measured in urine specimens collected after blood transfusion.

Rapid determination of urinary di(2-ethylhexyl) phthalate metabolites based on liquid chromatography/tandem mass spectrometry as a marker for blood transfusion in sports drug testing.

Methods of blood doping such as autologous and homologous blood transfusion are one of the main challenging doping practices in competitive sport. Whereas homologous blood transfusion is detectable via minor blood antigens, the detection of autologous blood transfusion is still not feasible. A promising approach to indicate homologous or autologous blood transfusion is the quantification of increased urinary levels of di(2-ethylhexyl) phthalate (DEHP) metabolites found after blood transfusion. The commonly used plasticizer for flexible PVC products, such as blood bags, is DEHP which is known to diffuse into the stored blood. Therefore, a straight forward, rapid and reliable assay is presented for the quantification of the main metabolites mono(2-ethyl-5-oxohexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethylhexyl) phthalate that can easily be implemented into existing multi-target methods used for sports drug testing. Quantification of the DEHP metabolites was accomplished after enzymatic hydrolysis of urinary glucuronide conjugates and direct injection using isotope-dilution liquid chromatography/tandem mass spectrometry. The method was fully validated for quantitative purposes considering the parameters specificity, linearity (1-250 ng/mL), inter- (2.4%-4.3%) and intra-day precision (0.7%-6.1%), accuracy (85%-105%), limit of detection (0.2-0.3 ng/mL), limit of quantification (1 ng/mL), stability and ion suppression effects. Urinary DEHP metabolites were measured in a control group without special exposure to DEHP (n = 100), in hospitalized patients receiving blood transfusion (n = 10), and in athletes (n = 468) being subject of routine doping controls. The investigation demonstrates that significantly increased levels of secondary DEHP metabolites were found in urine samples of transfused patients, strongly indicating blood transfusion.

Metastatic carcinoid presenting as a breast lesion.

Metastasis to the breast is a rare occurrence, constituting fewer than 2% of all breast tumours. Of all metastatic tumours in the breast, most arise from contralateral breast primaries. Other reported primary solid tumour sites include melanoma; lung, gastric, and renal cancers; and approximately 29 cases of carcinoid tumour.Ambiguous presentations and an absence of carcinoid syndrome features make accurate radiographic and histologic assessment of breast carcinoids challenging. Here, we report the case of a 52-year-old woman who presented with a mammographic abnormality in the left breast. Excisional biopsy revealed histopathology consistent with carcinoid. After an exhaustive work-up, carcinoid within the terminal ileum was ultimately identified, and the woman was diagnosed with metastatic breast carcinoid, an exceedingly rare entity. This paper describes the common mammographic, cytologic, and immunohistochemical features typical of metastatic breast carcinoid tumours, together with their common clinical features, prognosis, and treatment options.

Bilateral iatrogenic [corrected] maxillary fractures after dental treatment in two aged horses.

This clinical report describes two horses with bilateral maxillary fractures following dental treatment. The fractures occurred during dental treatment by a veterinarian, and both had rostral, transverse, and complete bilateral maxillary fractures with instability and minimal displacement. The fractures were repaired using bilateral intraoral wiring with the patients under general anesthesia. The postoperative period was without complications and the fractures healed as expected. Maxillary fractures during or after routine dental treatment are rare, but can occur, especially in older horses. Appropriate sedation and, if necessary, regional nerve blocks might reduce the risk of iatrogenic fractures of the maxilla. General anesthesia must be considered for tooth extraction in horses that are difficult to restrain.

Extraskeletal myxoid chondrosarcoma of the heart and review of current literature.

Extraskeletal myxoid chondrosarcoma (EMS) is a rare oncologic phenomenon characterized by chondroid and neurogenic differentiation in extraskeletal locations. These tumours represent fewer than 2.5% of all soft-tissue sarcomas and are most commonly found in the lower extremities, limb girdles, distal extremities, and trunk. Their presence in cardiac tissue is exceedingly unusual; just a single case of ems metastatic to the heart has been reported, and no cases of primary cardiac EMS are known.Here, we report the case of a 26-year-old man who presented to his physician with a chest wall mass. Further evaluation led to the discovery of a large intracardiac mass with multiple end-organ growths. Complete work-up of this patient included cardiac biopsy, echocardiography, magnetic resonance imaging, positron-emission tomography, computed tomography, and fluorescence in situ hybridization studies for the translocation involving the EWSR1 gene locus (22q12). Results of the foregoing studies confirmed the diagnosis of ems, but the origin of this patient's tumours remains elusive and the contention between a primary cardiac source and cardiac metastasis has yet to be resolved.This article describes the histopathology, immunohistochemistry, and chromosomal aberrations common to ems, together with the common presenting features, natural history, and prognosis.

[Feed-related selenium poisoning in swine]. / Fütterungsbedingte Selen-Vergiftung beim Schwein.

The following case report describes a selenium toxicosis in a pig-fattening farm of two finisher groups. The diseased animals partly showed ataxia and paresis or intense lameness in connection with band-like ablation of the epidermis at the coronary band. Some of them suffered from alopecia. Foot-and-mouth disease and swine vesicular disease were excluded by serological tests. Dissection revealed a multifocal bilateral symmetric poliomyelomalacia. Histological changes in the claws ranged from severe cell-decay in the germinative layer to distinctive decay of the stratum corneum. Due to damage of the claw epidermis the corium was partly exposed. Feed analysis revealed 100-fold increased selenium content in the finishing premix from the feed mill and as a result 20- to 60-fold increased selenium values in feed samples from the farm-made finisher mixture. Selenium concentration in the blood of diseased animals was 4- to 10-fold higher than normal values, which confirmed the tentative diagnosis of a selenium toxicosis.

[Surgical treatment of canker involving all hoofs in a warmblood gelding]. / Die chirurgische Behandlung von Strahlkrebs an allen vier Gliedmassen bei einem Warmblutwallach.

The following case report describes the treatment of canker in a 14 years old warmblood gelding. The horse showed the typical appearance with caseous surface and early detachment of the superficial horn layers. The histological results show a severe degradation in the germinal layer of the epidermis of the frog. Surgical therapy under general anaesthesia was performed. On all limbs a tourniquet was applied and all abnormal tissue in the region of the frog and also the subdermal tissue underneath were removed. Postoperatively the horse was treated with hoof bandages for 2 weeks. Treatment plates were than applied on all hoofs. During the following weeks the wounds were topically treated with Giessner Mischung 2 an astringent, desinfectant powder. The powder contains jodophorm, zincoxyde, tanninic acid, metronidazole. After 5 months the frog showed a complete cover with strong horn material and without any signs of recrudescence.

Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement.

OBJECTIVES: To investigate whether the administration of the zinc-containing nutritional supplement ZMA causes an increase of serum testosterone levels, which is an often claimed effect in advertising for such products; to monitor the urinary excretion of testosterone and selected steroid hormone metabolites to detect potential changes in the excretion patterns of ZMA users. SUBJECTS: Fourteen healthy, regularly exercising men aged 22-33 years with a baseline zinc intake between 11.9 and 23.2 mg day(-1) prior to the study. RESULTS: Supplementation of ZMA significantly increased serum zinc (P=0.031) and urinary zinc excretion (P=0.035). Urinary pH (P=0.011) and urine flow (P=0.045) were also elevated in the subjects using ZMA. No significant changes in serum total and serum free testosterone were observed in response to ZMA use. Also, the urinary excretion pattern of testosterone metabolites was not significantly altered in ZMA users. CONCLUSIONS: The present data suggest that the use of ZMA has no significant effects regarding serum testosterone levels and the metabolism of testosterone in subjects who consume a zinc-sufficient diet.