Influence of short-term chronic oral cannabidiol application on muscle recovery and performance after an intensive training protocol - a randomized double-blind crossover study

BACKGROUND

Rapid regeneration after intense exercise is essential for competitive athletes. Based on this assumption, supplementation strategies, focusing on food supplements, are increasing to improve the recovery processes. One such supplement is cannabidiol (CBD) which is gaining more attention in competitive sports. However, the evidence is still lacking and there are no data available about the effect of a short-term chronic application.

METHODS

A three-arm double-blind cross-over study was conducted to determine the effects of two different CBD products on performance, muscle damage and inflammatory processes in well-trained athletes. In total 17 subjects took successfully part in this study. Each subject underwent the six-day, high-intensity training protocol three times. After each training session, each subject took either a placebo or a CBD product (60 mg of oil or solubilisate). Between the intervention phases, at least four weeks of washout period was conducted. Before and after the training protocols the performance capacity in countermovement jump (CMJ), back squat (BS), bench press (BP) and 1-mile run were measured and biomarkers for muscle damage (creatine kinase, myoglobin), inflammatory processes (interleukin 6 and 10) and immune cell activity (ratios of neutrophil granulocytes, lymphocytes and, platelets) were analyzed. For statistical analyses, the current version of R and a linear mixed model was used.

RESULTS

It could identify different effects of the training protocol depending on performance level (advanced or highly advanced athletes) (p < .05). Regardless of the performance level, muscle damage and a reduction in performance could be induced by the training protocol. Only CBD oil was associated with a reduction in myoglobin concentration (p < .05) in advanced athletes. Concerning immune activity, a significant decrease in platelets lymphocyte ratios was observed in advanced athletes after placebo treatment (p < .05). CBD oil application showed a slight inhibitory effect (p < .10). Moreover, the reduction in performance differs between the performance levels. A significant decrease in CMJ was observed in advanced athletes and a decreasing trend in BS was observed in highly advanced athletes after placebo treatment (p < 0.10). Both CBD products do not affect performance parameters. For inflammatory parameters, no effects were observed.

CONCLUSION

It was found that the performance level of the subjects was a decisive factor and that they responded differently to the training protocol and the CBD application. However, no clear effects of either CBD product were found and further research is needed to identify the long-term effects of CBD application.

Differences in Consumption Behaviour of Dietary Supplements in Competitive Athletes Depends on Sports Discipline

BACKGROUND

The consumption of dietary supplements (DS) is widespread among the general population and competitive athletes. However, only a few competitive athletes seek information from experts about the effects and use of DS. Furthermore, it is currently unknown whether certain sports have a higher affinity for DS than others.

METHODS

This study aimed to identify differences between different sports categories and subgroups that may have a very high affinity for DS. For this purpose, competitive athletes were surveyed. The survey included the type of sport, the training frequency, the number of competitions, the consumption behaviour of five DS categories (general health, regeneration promotion, performance enhancement, booster, and weight loss) as well as personal data such as biological sex and age. Subsequently, correlations, configural frequencies (CFA), and multiple correspondence analyses (MCA) were used to identify subgroups with a high affinity of consumption behaviour.

RESULTS

A total of 409 questionnaires could be evaluated. It was found that all DS categories except weight loss were related. In addition, it was observed that in sports from the power category and from the endurance category, there was even higher consumption behaviour than in other sports categories. Male power athletes in particular have a higher affinity for consuming DS than other subgroups.

CONCLUSIONS

This study shows that there is a clear different consumption behaviour depending on the type of sport. Male power athletes in particular are the subgroup with the greatest consumption behaviour and therefore require special education on the effects and use of DS. This subgroup in particular should receive increased attention in counselling on DS to minimise the possible risks of DS use.

Resistance training alters body composition in middle-aged women depending on menopause - A 20-week control trial

BACKGROUND

Resistance training (RT) is effective in counteracting the age- and menopause-related loss of muscle mass (MM) and strength in middle-aged women (40-60 years). Research on RT with free weights is limited in pre- and post-menopausal women. Based on this, a 20-week training intervention was conducted with this population to investigate the effects of systematic RT with free weights on strength capacity and body composition.

METHOD

Forty-one healthy women (52.0 ± 3.6 years) participated in this study. After 10-week control phase (no RT, T0-T1) followed by a 10-week intervention phase (T1-T2) with RT twice a week and 6-8 sets of each muscle per week. Subjects were randomly assigned to a low-intensity (50% 1-RM) or moderate-intensity (75% 1-RM) RT group and divided into pre-menopausal and post-menopausal according to their hormone profile. Fat-free mass (FFM), MM, fat mass (FM), muscle thickness (Vastus lateralis (VL), Rectus femoris (RF), Triceps brachii (TB)), grip strength, 1-RM squat and bench press were assessed before and after each phase. Statistical analysis was performed using a linear mixed model to account for fixed (time and group) and random (individual) effects.

RESULTS

A total of 31 women successfully completed the study. No injuries occurred during the intervention. Significant increases in 1-RM squat and bench press were observed in all groups. No interaction effect was observed for the strength parameters. In pre-menopausal women, FFM, MM and RF muscle thickness increased significantly, while VL showed a trend. These effects were not present in post-menopausal women regardless of RT intensity.

CONCLUSION

RT with free weight is safe and effective for middle-aged women to increase 1-RM. Hypertrophy effects were found exclusively in pre-menopausal women. To achieve hypertrophy and/or body composition changes in post-menopausal women, larger training volumes (> 6-8 sets/muscle per week) are likely required.

The Anabolic Effect of Fenugreek: A Systematic Review with Meta-analysis

The use of plant steroids to improve physical health and performance is becoming increasingly popular. One of these plant steroids is diosgenin, which is mainly available in fenugreek. As a result, some studies have been conducted to improve physical health. Fenugreek extracts are also becoming increasingly popular in the context of athletic performance. Based on these assumptions, a systematic review with meta-analysis was conducted to evaluate the promoting effects of fenugreek on strength performance, body composition, and hormone concentration. Four databases were screened according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The current version of ReviewManager (RevMan) was used for the statistical evaluation. Seven studies with 449 participants (378 male, 71 female) met the inclusion criteria. A small effect of fenugreek was detected for total testosterone (standard mean difference (SMD): 0.32; 95% confidence interval (CI): 0.09 0.55), free testosterone (SMD: 0.24; 95% CI: -0.04, 0.52), lean body mass (SMD: 0.19; 95% CI: -0.10, 0.49), fat mass (SMD: -0.19; 95% CI: -0.44, 0.05), and leg press performance (SMD: 0.22; 95% CI: -0.02, 0.47), in male athletes. The meta-analysis shows that chronic application of fenugreek has performance-enhancing and anabolic effects in male athletes, but no statements can be made for female athletes.

Combinatory Effects of Training and Nutritive Administration of Carbohydrates and Protein via Food on Strength in Postmenopausal Women, and Old Men and Women

The age-related loss of muscle mass promotes many impairments. Training and protein supplementation are suggested to prevent muscle wasting, but recommendations for all populations are not based on scientific evidence. This study combines protein/carbohydrate supplementation (PCS) and training for seniors and postmenopausal women. Project A: 51 postmenopausal women (PMW, 57.3 ± 3.0 years old) underwent health-oriented training (12 weeks, moderate-strength training + moderate-endurance training). The intervention group (IG) additionally received 110 g sour milk cheese (SMC) and toast. Project B: 25 women and 6 men (65.9 ± 4.9 years old) performed intense sling training (12 weeks). The IG additionally received 110 g SMC, toast, and buttermilk. Strength was tested before and after in both studies. Project A: there was significant increase in strength, no additional effect of PCS, and a reduction in body fat in the controls. Project B: there was significant increase in strength, significant additional effects of PCS for trunk strength, and a significant reduction in body weight. Combining training and PCS may counteract strength loss. Combined endurance/resistance training is recommended to PMW for whom the benefits of PCS are restricted. Aged subjects may benefit from PCS when training intensely, but these benefits may be strongly individual.

Effects of Carbohydrate and Protein Administration by Food Items on Strength Response after Training in Stable COPD

Background: Chronic obstructive pulmonary disease (COPD) is one of the world’s most common diseases and reasons for death. Systemic consequences, especially reduced muscle strength, muscle mass and muscle function, are common and contribute to worsening prognosis and increasing morbidity and mortality. There is strong evidence that physical activity and strength training are effective in prolonging life and lead to better quality of life. Numerous studies have shown that ingestion of protein and carbohydrates after strength training can increase regeneration of strength in young athletes. Recently, we demonstrated that the same effect can be achieved with these macronutrients administered in a meal. Until now, it is not clear if patients with COPD, integrated in regular physical training, respond similarly. Methods: Prescribed strength training, consisting of two sets circular training with machines for big muscle groups was supplemented with a meal rich in protein and carbohydrates. Changes in maximum strength after 24 h were investigated to find out about the impact of this meal on physical capacity. A pilot study was conducted with pragmatic cross-over design. Results: With nutritive intervention, strength in both knee extensor and chest press were significantly higher than in control training. Conclusion: The study showed beneficial effects for the intake of protein and carbohydrates in changes in maximum strength. For now, the underlying mechanism remains unclear. Clinical relevance needs further research. The study design and study protocol can be used for further studies with only small adaptions.

Effects of acute aerobic exercise on fatmetabolism in pre- and postmenopausal women of comparable body mass index

Problem: With menopause, the risk of cardiovascular diseases (CVD) increases significantly. A possible molecular mechanism is an estrogen-related change in fat metabolism. Endurance training has been demonstrated to reduce the risk of CVD and to have an impact on fat metabolism (FM). This study aims to analyze the ability of pre- (preW) and postmenopausal women (postW) of comparable body mass index (BMI) to activate their FM during endurance training. Methods: 12 preW and 12 postW were included. Serum Triglyceride, LDL, HbA1C, estradiol and body composition data were determined. The respiratory quotient (RQ) was determined during moderate 30-minute exercise (60% of the 4 mmol threshold) on an ergometer. Results: While the BMI of preW and postW was comparable, body fat (BF) (p=0.001), lean body mass (LBM) (p=0.001) and abdominal girth (AG) (p=0.003) were significantly different. Significant group effects could also be identified in HbA1c (p=0.001), cholesterol (p=0.001) and LDL (p=0.000) serum concentrations. RQ decreased during 30 minutes of cycling in preW and increased in postW (p=0.010) over time. Discussion: The higher AG and BF and the lower LBM demonstrates the change in body composition in postW. An accumulation of fat, especially in the trunk region, goes along with an increase of CVD in postW, even with a normal BMI. Conclusion: It is evident that postW show altered lipid metabolism compared to preW. Key Words: Menopause, Cardiovascular Risk Factor, Aerobic Training, Metabolism

Hormonal response after masturbation in young healthy men - a randomized controlled cross-over pilot study

BACKGROUND

Hormones like testosterone play a crucial role in performance enhancement and muscle growth. Therefore, various attempts to increase testosterone release and testosterone concentration have been made, especially in the context of resistance training. Among practitioners, sexual activity (coitus and masturbation) a few hours before training is often discussed to result in increases of testosterone concentration and thus promote muscle growth. However, there is no evidence to support this assumption and the kinetics of the testosterone and cortisol response after sexual activity have not been adequately investigated. Therefore, the aim of this pilot-study was to examine the kinetics of hormone concentrations of total testosterone, free testosterone and cortisol and their ratios after masturbation. In a three-arm single blinded cross-over study, the effects of masturbation with visual stimulus were compared to a visual stimulus without masturbation and the natural kinetics in healthy young men.

RESULTS

The results showed a significant between-condition difference in free testosterone concentrations. Masturbation (p < 0.01) and a visual stimulus (p < 0.05) may seem to counteract the circadian drop of free testosterone concentrations over the day. However, no statistical change was observed in the ratios between total testosterone, free testosterone and cortisol.

CONCLUSIONS

It can be assumed that masturbation may have a potential effect on free testosterone concentrations but not on hormonal ratios. However, additional studies with larger sample sizes are needed to validate these findings.

Effects of Cannabidiol Supplementation on Skeletal Muscle Regeneration after Intensive Resistance Training

Cannabidiol supplements (CBD) are increasingly consumed by athletes to improve regeneration. However, the evidence for the pro-regenerative effects of CBD in sports is quite limited. Therefore, our aim was to investigate the effects of a single CBD supplementation in a six-arm placebo-controlled crossover study after resistance training on performance and muscle damage. Before and after the resistance training, one-repetition maximum in the back squat (1RM BS), countermovement jump (CMJ), and blood serum concentrations of creatine kinase (CK) and myoglobin (Myo) were measured in healthy, well-trained participants. 16 out of 21 participants completed the study and were included in the analysis. In 1RM BS, a significant decrease was observed after 24 h (p < 0.01) but not after 48 and 72 h. A significant group difference was detected after 72 h (p < 0.05; ES = 0.371). In CMJ, no significant changes were observed. The CK and Myo concentrations increased significantly after 24 h (CK: p < 0.001; Myo: p < 0.01), 48 h (CK: p < 0.001; Myo: p < 0.01) and 72 h (CK: p < 0.001; Myo: p < 0.001). After 72 h, significant group differences were observed for both muscle damage biomarkers (CK: p < 0.05 ES = 0.24; Myo: p < 0.05; ES = 0.21). The results show small but significant effects on muscle damage and recovery of squat performance after 72 h. However, more data are required for clearer statements concerning potential pro-regenerative effects of CBD supplementation after resistance training.

Prediction of human dietary δ15N intake from standardised food records: validity and precision of single meal and 24-h diet data

Natural stable isotope ratios (δ¹⁵N) of humans can be used for nutritional analyses and dietary reconstruction of modern and historic individuals and populations. Information about an individual's metabolic state can be obtained by comparison of tissue and dietary δ¹⁵N. Different methods have been used to estimate dietary δ¹⁵N in the past; however, the validity of such predictions has not been compared to experimental values. For a total of 56 meals and 21 samples of 24-h diets, predicted and experimental δ¹⁵N values were compared. The δ¹⁵N values were predicted from self-recorded food intake and compared with experimental δ¹⁵N values. Predicted and experimental δ¹⁵N values were in good agreement for meals and preparations (r = 0.89, p < .001) as well as for the 24-h diets (r = 0.76, p < .001). Dietary δ¹⁵N was mainly determined by the amount of fish, whereas the contribution of meat to dietary δ¹⁵N values was less pronounced. Prediction of human dietary δ¹⁵N values using standardised food records and representative δ¹⁵N data sets yields reliable data for dietary δ¹⁵N intake. A differentiated analysis of the primary protein sources is necessary when relating the proportion of animal-derived protein in the diet by δ¹⁵N analysis.

Do we excrete what we eat? Analysis of stable nitrogen isotope ratios of human urinary urea

RATIONALE

Natural stable nitrogen isotope ratios (δ¹⁵ N) are frequently used for the determination of provenance and dietary assessment of recent and ancient humans. Although individual δ¹⁵ N values typically correspond to the dietary δ¹⁵ N composition, they are also affected by metabolic conditions. Preferred matrices for the measurement of human δ¹⁵ N values have been hair, nail or blood. The goal of this study was to validate a novel approach for the assessment of the δ¹⁵ N values from urinary urea, the principal end-product of human N metabolism.

METHODS

The method, which involves the precipitation of urea from urine using xanthydrol, was validated using fortified urea solutions. Intra- and inter-individual variance of the δ¹⁵ N values of urinary urea was determined from samples obtained from multiple human subjects.

RESULTS

Precipitation with xanthydrol did not alter the δ¹⁵ N values of urea. The mean δ¹⁵ N value in urinary urea from human subjects from Germany was +4.4 ± 0.6 ‰, which corresponds to the estimated dietary composition. It falls below previously reported δ¹⁵ N values for human tissue and blood samples. Longitudinal analyses over 7 days illustrate short-time changes linked to varying protein intake.

CONCLUSIONS

Our results indicate that δ¹⁵ N values can be measured reliably from human urine and that the method is suitable to monitor rapid dietary and metabolic changes of an individual. Our findings further confirm that urinary urea is depleted in ¹⁵ N compared with human tissue but within the range of the δ¹⁵ N composition of the diet. Copyright © 2017 John Wiley & Sons, Ltd.

Global spatial distributions of nitrogen and carbon stable isotope ratios of modern human hair

RATIONALE

Natural stable carbon (δ(13)C) and nitrogen isotope ratios (δ(15)N) of humans are related to individual dietary habits and environmental and physiological factors. In forensic science the stable isotope ratios of human remains such as hair and nail are used for geographical allocation. Thus, knowledge of the global spatial distribution of human δ(13)C and δ(15)N values is an essential component in the interpretation of stable isotope analytical results.

METHODS

No substantial global datasets of human stable isotope ratios are currently available, although the amount of available (published) data has increased within recent years. We have herein summarised the published data on human global δ(13)C andδ(15)N values (around 3600 samples) and added experimental values of more than 400 additional worldwide human hair and nail samples. In order to summarise isotope ratios for hair and nail samples correction factors were determined.

RESULTS

The current available dataset of human stable isotope ratios is biased towards Europe and North America with only limited data for countries in Africa, Central and South America and Southeast Asia. The global spatial distribution of carbon isotopes is related to latitude and supports the fact that human δ(13)C values are dominated by the amount of C4 plants in the diet, either due to direct ingestion as plant food, or by its use as animal feed. In contrast, the global spatial distribution of human δ(15)N values is apparently not exclusively related to the amount of fish or meat ingested, but also to environmental factors that influence agricultural production.

CONCLUSIONS

There are still a large proportion of countries, especially in Africa, where there are no available data for human carbon and nitrogen isotope ratios. Although the interpretation of modern human carbon isotope ratios at the global scale is quite possible, and correlates with the latitude, the potential influences of extrinsic and/or intrinsic factors on human nitrogen isotope ratios have to be taken into consideration.

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17β-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of (13)C-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of (13)C-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway.

Physiological and metabolic responses as function of the mechanical load in resistance exercise

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake (V̇O2) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. V̇O2 exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways.

Molecular effects of ER alpha- and beta-selective agonists on regulation of energy homeostasis in obese female Wistar rats

The molecular mechanisms underlying the effects of selective ER subtype activation on lipogenesis, adipogenesis, lipid utilization and storage as well as glucose metabolism are currently largely unknown and were analyzed in female OVX Wistar rats on a high-fat diet. Rats received estradiol (E2), ER subtype-selective agonists (Alpha and Beta), and genistein (Gen) for 10 weeks. In adipose tissue, treatment with E2, Alpha, and Beta significantly decreased lipogenic (SREBP-1c, FAS) and adipogenic genes (LPL, PPAR gamma). In liver and skeletal muscle of E2-, Alpha-, Beta-, and Gen-treated animals, lipogenesis and triglyceride accumulation were significantly reduced. Increased hepatic and muscular PPAR gamma mRNA expression was observed in untreated, Beta- and Gen-treated animals, which correlates with increased hepatic glucose uptake. However, only untreated animals showed impaired insulin sensitivity compared to all other groups. Therefore, PPAR gamma up-regulation in untreated animals suggests a compensatory mechanism, probably due to increased triglyceride accumulation in non-adipose tissues. Beta- and Gen-treated animals may benefit from the anabolic potency of ER beta that ameliorates lipid and glucose utilization in muscle. Activation of either ER subtype reduces fat enrichment and improves insulin sensitivity. Depending on the investigated tissue, different molecular pathways seem to be involved.

Traditional Chinese medicine and sports drug testing: identification of natural steroid administration in doping control urine samples resulting from musk (pod) extracts

The administration of musk extract, that is, ingredients obtained by extraction of the liquid secreted from the preputial gland or resulting grains of the male musk deer (eg, Moschus moschiferus), has been recommended in Traditional Chinese Medicine (TCM) applications and was listed in the Japanese pharmacopoeia for various indications requiring cardiovascular stimulation, anti-inflammatory medication or androgenic hormone therapy. Numerous steroidal components including cholesterol, 5α-androstane-3,17-dione, 5β-androstane-3,17-dione, androsterone, etiocholanolone, epiandrosterone, 3β-hydroxy-androst-5-en-17-one, androst-4-ene-3,17-dione and the corresponding urea adduct 3α-ureido-androst-4-en-17-one were characterised as natural ingredients of musk over several decades, implicating an issue concerning doping controls if used for the treatment of elite athletes. In the present study, the impact of musk extract administration on sports drug testing results of five females competing in an international sporting event is reported. In the course of routine doping controls, adverse analytical findings concerning the athletes' steroid profile, corroborated by isotope-ratio mass spectrometry (IRMS) data, were obtained. The athletes' medical advisors admitted the prescription of TCM-based musk pod preparations and provided musk pod samples for comparison purposes to clarify the antidoping rule violation. Steroid profiles, IRMS results, literature data and a musk sample obtained from a living musk deer of a local zoo conclusively demonstrated the use of musk pod extracts in all cases which, however, represented a doping offence as prohibited anabolic-androgenic steroids were administered.

Determination of salbutamol and salbutamol glucuronide in human urine by means of liquid chromatography-tandem mass spectrometry

The determination of salbutamol and its glucuronide in human urine following the inhalative and oral administration of therapeutic doses of salbutamol preparations was performed by means of direct urine injection utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS) and employing d(3)-salbutamol and d(3)-salbutamol glucuronide as internal standards. Unconjugated salbutamol was detected in all administration study urine samples. Salbutamol concentrations following inhalation were commonly (99%) below 1000 ng/ml whereas values after oral administration frequently (48%) exceeded this threshold. While salbutamol glucuronide was not detected in urine samples collected after inhalation of the drug, 26 out of 82 specimens obtained after oral application contained salbutamol glucuronide with a peak value of 63 ng/ml. The percentage of salbutamol glucuronide compared to unconjugated salbutamol was less than 3%. Authentic doping control urine samples indicating screening results for salbutamol less than 1000 ng/ml, showed salbutamol glucuronide concentrations between 2 and 6 ng/ml, whereas adverse analytical findings resulting from salbutamol levels higher than 1000 ng/ml, had salbutamol glucuronide values between 8 and 15 ng/ml. The approach enabled the rapid determination of salbutamol and its glucuronic acid conjugate in human urine and represents an alternative to existing procedures since time-consuming hydrolysis or derivatization steps were omitted. Moreover, the excretion of salbutamol glucuronide in human urine following the administration of salbutamol was proven.

Determination of (13)C/(12)C ratios of urinary excreted boldenone and its main metabolite 5beta-androst-1-en-17beta-ol-3-one

Boldenone (androsta-1,4-dien-17beta-ol-3-one, Bo) is an anabolic steroid known to have been used in cattle breeding or equine sport as a doping agent for many years. Although not clinically approved for human application, Bo or its main metabolite 5beta-androst-1-en-17beta-ol-3-one (BM1) were detected in several doping control samples. For more than 15 years the possibility of endogenous Bo production in human beings has been discussed. This is a challenging issue for doping control laboratories as Bo belongs to the list of prohibited substances of the World Anti-Doping Agency and therefore the chance for false positive testing is significant. By GC/C/IRMS (gas chromatography/combustion/isotope ratio mass spectrometry) it should be possible to analyze the (13)C/(12)C ratio of either Bo or BM1 and to distinguish whether their source is endogenous or exogenous. Therefore a method was developed to determine the (13)C/(12)C ratios of Bo, BM1, pregnanediol, androsterone, etiocholanolone, and testosterone from a single urine specimen. The validity of the method was ensured by repeated processing of urine fortified with 2-50 ng/mL Bo and BM1. The specificity of the method was ensured by gas chromatography/mass spectrometry determinations. Out of 23 samples investigated throughout the last four years, 11 showed (13)C/(12)C ratios of Bo or BM1 inconsistent with an exogenous origin. Two of these samples were collected from the same athlete within a one-month interval, strongly indicating the chance of endogenous Bo production by this athlete.

Sports-related issues and biochemistry of natural and synthetic anabolic substances

Testosterone is the principal male sex hormone. As with all natural steroids, it is biosynthesized from cholesterol. Phase I metabolism employs some very specific enzymes and pathways. Phase II metabolism and excretion follow more general patterns. The effects of testosterone are twofold: anabolic and androgenic. Because of its anabolic effects, testosterone is frequently abused in sports. Because of its endogenous nature, testosterone doping is difficult to detect. The standard procedure is based on the evaluation of the urinary steroid profile. Conspicuous samples then are submitted to compound-specific (13)C/(12)C analysis. Synthetic and endogenous steroids differ in this measure. Numerous xenobiotic compounds have been derived from testosterone. The modifications typically aim at a reduction of the androgenic properties while maintaining the anabolic potential. Most of these compounds have been withdrawn from the legal market. However, they are found to be illicitly added to otherwise inefficient nutritional supplements. These products represent a major problem to doping control. Recently, clinical trials with selective androgen receptor modulators have been started.

Effect of a controlled dietary change on carbon and nitrogen stable isotope ratios of human hair

The carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope ratios of human hair can be used for the interpretation of dietary habits and nutritional status in contemporary or past populations. Although the results of bulk or segmental isotope ratio analysis of human hair have been used for the reconstruction of an individual's diet for years, only limited data of controlled dietary changes on the carbon and nitrogen isotopic composition of human hair are available. Hair of four individuals, two males and two females, who participated in a dietary change experiment for 28 days was segmentally analysed for delta(13)C and delta(15)N. The dietary change included a change from C3 to C4 plant enriched diets and a simultaneous replacement of terrestrial animal products by marine products. This resulted in an increase in delta(13)C(diet) of +8.5 to +9.9 per thousand and in delta(15)N(diet) of +1.5 to +2.2 per thousand. All subjects showed significant increases in delta(13)C(hair) and delta(15)N(hair) during the dietary change period, although no subject reached a new steady state for either carbon or nitrogen. The change in delta(15)N(hair) was faster than the change in delta(13)C(hair) for all individuals. The magnitude of change of the isotopic composition during the dietary change period could be attributed to the degree of physical activity of the individuals, with a higher physical activity resulting in a faster change.

Determination of the deuterium/hydrogen ratio of endogenous urinary steroids for doping control purposes

The development and application of a combined gas chromatography/thermal conversion/isotope ratio mass spectrometry (GC/TC/IRMS) method for D/H ratio determination of endogenous urinary steroids are presented. The key element in sample preparation was the consecutive cleanup with high-performance liquid chromatography of initially native and subsequently acetylated steroids. This strategy enabled sufficient cleanup off all target analytes for determination of their respective D/H values. Ten steroids (11beta-hydroxyandrosterone, 5alpha-androst-16-en-3alpha-ol, pregnanediol, androsterone, etiocholanolone, testosterone, epitestosterone, 5alpha-androstan-3alpha,17beta-diol, 5beta-androstan-3alpha,17beta-diol and dehydroepiandrosterone) were measured from a single urine specimen. Depending on the biological background, the determination limit for all steroids ranged from 10 to 15 ng/mL for a 20 mL specimen. The method was validated by application of linear mixing models on each steroid and covered repeatability and reproducibility. The specificity of the procedure was ensured by gas chromatography/mass spectrometry (GC/MS) analysis of the sample using equivalent chromatographic conditions to those employed in the GC/TC/IRMS measurement. Within the sample preparation, no isotopic fractionation was observed, and no amount-dependent shift of the D/H ratios during the measurement was noticed. Possible memory effects occurring during IRMS measurements were corrected by applying a simple rule of proportion. In order to determine the naturally occurring D/H ratios of all implemented steroids, a population of 18 male subjects was analyzed. Relevant mean Delta values among selected steroids were calculated which allowed us to study the metabolic pathways and production sites of all the implemented steroids with additional consideration of the corresponding (13)C/(12)C ratios.

Excretion of norsteroids' phase II metabolites of different origin in human

The urinary phase II metabolites of norsteroids, 19-norandrosterone, 19-noretiocholanolone and 19-norepiandrosterone glucuronide and sulphate, were analyzed in samples collected during the pregnancy, following the administration of norsteroids or the consumption of edible parts of non-castrated pig and in athletes' samples in which they were found during routine controls. The level of the sulfo- and glucuroconjugated metabolites was precisely determined by GC/HRMS, after selective hydrolysis. The goal was to evaluate whether the fine analysis of the norsteroid conjugates produced and excreted in different conditions would show a pattern that could be linked to their origin. The delta (13)C values of the metabolites formed following the ingestion of edible parts of non-castrated pig were measured by isotope ratio mass spectrometry. Our results indicated that it is not possible to determine the origin of the urinary metabolites based upon the sole evaluation of the different metabolites and conjugates. The GC/C/IRMS is the only method permitting to distinguish between the exogenous and endogenous origin of the metabolites.

Stability tests for hematological parameters in antidoping analyses

The purpose of this study was to evaluate the influences of delayed sample analysis on the stability of erythrocyte parameters and reticulocyte parameters for antidoping tests performed on the ADVIA120 system. We analyzed erythrocyte count, hemoglobin, hematocrit, mean cell volume, percentage of hypochromic erythrocytes, percentage of macrocytes, absolute reticulocyte count, percentage of reticulocytes, mean cell volume of reticulocytes, cell hemoglobin of reticulocytes, percentage of high-fluorescent reticulocytes, and OFF-Score during a 48-hour storage period at 4 degrees C or 21 degrees C. Data analysis was performed by fitting linear or nonlinear mixed-effects models. We then modeled appropriate trends and tested the curve parameters' interaction with the ambient temperature. We observed that chilling of samples to 4 degrees C generally proved more advantageous than storage at room temperature. Sufficient stability during 48-hour intervals was demonstrated for erythrocyte count, hemoglobin, percentage of reticulocytes, absolute reticulocyte count, cell hemoglobin of reticulocytes, percentage of hypochromic erythrocytes, percentage of high-fluorescent reticulocytes, and OFF-Score. We concluded that for the establishment of individual blood profiles the corresponding samples should be transported and stored at 4 degrees C. Analysis should be performed not later than 48 hours after sampling.

Stable carbon isotope discrimination by human 3-hydroxy-3-methylglutaryl-coenzyme A reductase

The aim of this study was to investigate the possible existence and magnitude of stable carbon isotope discrimination by human 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR). The catalytic portion of HMGR was expressed and purified. The reaction product mevalonate was lactonized and extracted from the reaction mixture by a solid-phase extraction protocol. Stable carbon isotope ratios of mevalonolactone (MVL) were analyzed by gas chromatography-combustion-isotope ratio mass spectrometry. An average fractionation factor (12)k/(13)k of 1.0031 +/- 0.0004 for all carbon atoms contained in MVL was estimated by the method of internal competition. The value was calculated by nonlinear curve fitting, where the ratio (13)C/(12)C of MVL was plotted versus the fraction of reaction.

Determination of 13C/12C ratios of endogenous urinary steroids: method validation, reference population and application to doping control purposes

The application of a comprehensive gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS)-based method for stable carbon isotopes of endogenous urinary steroids is presented. The key element in sample preparation is the consecutive cleanup with high-performance liquid chromatography (HPLC) of underivatized and acetylated steroids, which allows the isolation of ten analytes (11beta-hydroxyandrosterone, 5alpha-androst-16-en-3beta-ol, pregnanediol, androsterone, etiocholanolone, testosterone, epitestosterone, 5alpha-androstane-3alpha,17beta-diol, 5beta-androstane-3alpha,17beta-diol and dehydroepiandrosterone) from a single urine specimen. These steroids are of particular importance to doping controls as they enable the sensitive and retrospective detection of steroid abuse by athletes. Depending on the biological background, the determination limit for all steroids ranges from 5 to 10 ng/mL for a 10 mL specimen. The method is validated by means of linear mixing models for each steroid, which covers repeatability and reproducibility. Specificity was further demonstrated by gas chromatography/mass spectrometry (GC/MS) for each analyte, and no influence of the sample preparation or the quantity of analyte on carbon isotope ratios was observed. In order to determine naturally occurring (13)C/(12)C ratios of all implemented steroids, a reference population of n = 61 subjects was measured to enable the calculation of reference limits for all relevant steroidal Delta values.

The application of carbon isotope ratio mass spectrometry to doping control

The administration of synthetic steroid copies is one of the most important issues facing sports. Doping control laboratories accredited by the World Anti-Doping Agency (WADA) require methods of analysis that allow endogenous steroids to be distinguished from their synthetic analogs in urine. The ability to measure isotope distribution at natural abundance with high accuracy and precision has increased the application of Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GC-C-IRMS) to doping control in recent years. GC-C-IRMS is capable of measuring the carbon isotope ratio (delta(13)C) of urinary steroids and confirm their synthetic origin based on the abnormal (13)C content. This tutorial describes some of the complexities encountered by obtaining valid delta(13)C measurements from GC-C-IRMS and the need for careful interpretation of all relevant information concerning an individual's metabolism in order to make an informed decision with respect to a doping violation.

delta13C-values of endogenous urinary steroids

By means of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) urinary steroids obtained from a reference population of 56 subjects were analyzed for their (13)C/(12)C-ratios. The analytes encompassed androsterone (A), etiocholanolone (E), 11beta-hydroxyetiocholanolone (OHE), 11beta-hydroxyandrosterone (OHA), and 5beta-pregnane- 3alpha,20alpha-diol (PD). A and E represent androgen metabolites (AM). PD, OHE, and OHA have sources independent from androgen metabolism. The delta(13)C-values of the latter compounds may be compared to those of AM in order to detect doping with synthetic androgens and thus may serve as endogenous reference compounds (ERC). In order to allow for classification of conspicuous samples, reference ranges and limits were calculated for delta(13)C-values of selected steroids and differences hereof (Delta(13)C-values). When A is compared to ERCs, Delta(13)C-values larger than 3 per thousand are very unlikely. A set of additional parameters was surveyed by a questionnaire. Several factors turned out to exert significant influence on the delta(13)C-values of urinary steroids. These encompass the identity of the steroid itself, sex, oral contraception, travels, and physical activity.

Quantitative analysis of urinary glycerol levels for doping control purposes using gas chromatography-mass spectrometry

The administration of glycerol to endurance athletes results in an increased fluid retention and improved performance, particularly under hot and humid conditions. Consequently, glycerol is considered relevant for sports drug testing and methods for its detection in urine specimens are required. A major issue in this regard is the natural occurrence of trace amounts of glycerol in human urine, which necessitates a quantitative analysis and the determination of normal urinary glycerol levels under various sporting conditions. A quantitative method was established using a gas chromatography/isotope-dilution mass spectrometry-based approach that was validated with regard to lower limit of detection (0.3 microg mL(-1)), lower limit of quantification (0.9 microg mL(-1)), specificity, linearity (1.0-98.0 microg mL(-1)), intraday and interday precision (<20% at 2.4, 24.1 and 48.2 microg mL(-1)) as well as accuracy (92-110%). Sample aliquots of 20 microL were enriched with five-fold deuterated glycerol, dried and derivatised using N-methyl-trimethylsilyltrifluoroacetamide (MSTFA) before analysis. The established method was applied to a total of 1039 doping control samples covering various sport disciplines (349 endurance samples, 286 strength sport samples, 325 game sport samples and 79 other samples) in- and out-of-competition, which provided quantitative information about the glycerol content commonly observed in elite athletes' urine samples. About 85% of all specimens yielded glycerol concentrations < 20.0 microg mL(-1) and few reached values up to 132.6 microg mL(-1). One further sample, however, was found to contain 2690 microg mL(-1), which might indicate the misuse of glycerol, but no threshold for urinary glycerol concentrations has been established yet due to the lack of substantial data. Based on the results obtained from the studied reference population, a threshold for glycerol levels in urine set at 200 microg mL(-1) is suggested, which provides a tool to doping control laboratories to test for the misuse of this agent in elite and amateur sport.

Isolation of bicarbonate from equine urine for isotope ratio mass spectrometry

Sodium bicarbonate administration to horses prior to competition in order to enhance the buffer capacity of the organism is considered as a doping offence. The analysis of the isotopic composition of urinary bicarbonate/CO(2) (TCO(2)) may help to identify an exogenous bicarbonate source, as technical sodium bicarbonate exhibits elevated delta(13)C values compared with urinary total carbon. The isolation of TCO(2) from 60 equine urine samples as BaCO(3) followed by an isotopic analysis shows a significant variability of delta(13)C for TCO(2) of more than 10 per thousand. The delta(13)C of total carbon and TCO(2) seem to reflect different proportions of C3 and C4 plant material in the diet. The isotopic analysis of different mixtures of technical NaHCO(3) and equine urine shows that TCO(2) can be easily isolated without major isotopic fractionation; however, attention has to be paid to the storage time of urine samples, as a shift of delta(13)C of TCO(2) to lower values may occur.

Improved Performance and Maintenance in Gas Chromatography/Isotope Ratio Mass Spectrometry by Precolumn Solvent Removal

The crucial step in current concepts to interface isotope ratio mass spectrometry (IRMS) to gas chromatography (GC) is efficient solvent removal. This is due to the essential postcolumn conversion of the analytes into simple gases, which is performed by either combustion or pyrolysis. The capacity of this step merely suffices to convert the analytes. Already small amounts of solvent present in the respective furnace can cause severe damage. In conventional GC/IRMS interfaces, the solvent is removed after passage of the GC column. Either back-flushing or flow diversion is employed for this purpose. Both techniques necessitate the use of numerous components such as unions, tee pieces, valves, and capillary connections. Often this results in significant deterioration of the chromatographic resolution. In contrast, accurate GC/IRMS measurements require baseline separation of adjacent peaks. Moreover, maintenance of conventional interfaces may be tedious and time consuming, mostly because the numerous connections are prone to leakage. In order to avoid these drawbacks, we propose a concept to efficiently remove the solvent before passage of the GC column. It is based on the use of a cooled injection system operated in solvent vent mode, where the solvent elimination is supported by an auxiliary pump. Most unions and tee pieces thus can be removed. The chromatographic resolution is considerably enhanced. In particular, analysis of high-boiling and polar compounds can be improved. At the same time, the maintenance of the system is significantly facilitated. Under the chosen conditions, partial losses of low-boiling analytes during solvent elimination were not associated with significant isotope fractionation.

Doping-Control Analysis of the 5α-Reductase Inhibitor Finasteride: Determination of Its Influence on Urinary Steroid Profiles and Detection of Its Major Urinary Metabolite

5alpha-Reductase inhibitors such as finasteride are prohibited in sports according to the World Anti-Doping Agency. This class of drugs is used therapeutically to treat benign prostatic hyperplasia, as well as male baldness, by decreasing 5alpha-reductase activity. Accordingly, metabolic pathways of endogenous as well as synthetic steroids are influenced, which complicates the evaluation of steroid profiles in sports drug testing. The possibility of manipulating steroid excretion profiles and, presumably, to mask steroid abuse was investigated in 5 administration studies with use of finasteride at different doses, with and without coadministration of 19-norandrostenedione. The evaluation of urinary steroid profiles demonstrated the intense effect of finasteride on numerous crucial analytical parameters, in particular the production of 5alpha-steroids such as androsterone and 5alpha-androstane-3alpha,17beta-diol, which was significantly reduced. In addition, the excretion of the main metabolite of norandrostenedione, norandrosterone, was significantly suppressed, by up to 84%, in elimination studies. For doping-control analysis the use of 5alpha-reductase inhibitors causes considerable problems because steroid profile parameters, which are commonly considered stable, are highly affected and complicate the detection of steroid abuse. In addition, the suppression of production and renal excretion of 5alpha-steroids such as 19-norandrosterone generated from anabolic agents such as 19-norandrostenedione may lead to false-negative doping-control results, because urine specimens are reported positive only when a threshold level of 2 ng/mL is exceeded. Finally, a method for the determination of the major urinary metabolite of finasteride (carboxy-finasteride) in routine doping-control screening with use of liquid chromatography-tandem mass spectrometry is described, allowing the detection of carboxy-finasteride for up to 94 hours in urine specimens collected after an oral administration of 5 mg of finasteride.

Detection of dehydroepiandrosterone misuse by means of gas chromatography- combustion-isotope ratio mass spectrometry

According to World Anti-Doping Agency (WADA) rules (WADA Technical Document-TD2004EAAS) urine samples containing dehydroepiandrosterone (DHEA) concentrations greater than 100 ng ML(-1) shall be submitted to isotope ratio mass spectrometry (IRMS) analysis. The threshold concentration is based on the equivalent to the glucuronide, and the DHEA concentrations have to be adjusted for a specific gravity value of 1.020. In 2006, 11,012 doping control urine samples from national and international federations were analyzed in the Cologne doping control laboratory, 100 (0.9%) of them yielding concentrations of DHEA greater than 100 ng mL(-1). Sixty-eight percent of the specimens showed specific gravity values higher than 1.020, 52% originated from soccer players, 95% were taken in competition, 85% were male urines, 99% of the IRMS results did not indicate an application of testosterone or related prohormones. Only one urine sample was reported as an adverse analytical finding having 319 ng mL(-1) DHEA (screening result), more than 10,000 ng mL(-1) androsterone and depleted carbon isotope ratio values for the testosterone metabolites androsterone and etiocholanolone. Statistical evaluation showed significantly different DHEA concentrations between specimens taken in- and out-of- competition, whereas females showed smaller DHEA values than males for both types of control. Also a strong influence of the DHEA excretion on different sport disciplines was detectable. The highest DHEA values were detected for game sports (soccer, basketball, handball, ice hockey), followed by boxing and wrestling. In 2007, 6622 doping control urine samples were analyzed for 3alpha,5-cyclo-5alpha-androstan-6beta-ol-17-one (3alpha,5-cyclo), a DHEA metabolite which was described as a useful gas chromatography-mass spectrometry (GC-MS) screening marker for DHEA abuse. Nineteen urine specimens showed concentrations higher than the suggested threshold of 140 ng mL(-1), six urine samples yielded additionally DHEA concentrations higher than 100 ng mL(-1), none of them showing positive IRMS findings. These results should be taken into consideration in future discussions about threshold values for endogenous steroids in doping control.

Application of stable carbon isotope analysis to the detection of testosterone administration to cattle

The use of anabolic substances is prohibited in food-producing animals throughout the European Union. No method is available to reliably detect the misuse of natural hormones in cattle. A method was developed to detect the abuse of testosterone in cattle fattening. Synthesized testosterone is rather depleted in the (13)C/(12)C ratio. Hence, the method is based on gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) analysis of urine. To select testosterone metabolites and endogenous reference compounds (ERC), the concentration of urinary steroids of cattle was investigated. Dehydroepiandrosterone and androst-5ene-3beta,17alpha-diol were chosen as ERCs to show endogenous (13)C/(12)C ratios. Etiocholanolone and 5alpha-androstane-3beta,17alpha-diol were chosen as the most important testosterone metabolites. Other metabolites known from literature like epitestosterone were less promising. In principle, GC/C/IRMS is a nonspecific method because finally carbon dioxide is analyzed. Therefore, a dedicated cleanup procedure for the selected steroids was developed. By means of proposed confidence intervals in the isotopic composition of ERCs and metabolites, the administration of testosterone to cattle could be detected reliably. Differences of up to 11 per thousand on the delta-scale between ERC and testosterone metabolites were found after testosterone administration, whereas endogenous differences did not exceed 2 per thousand.

Determination of the origin of urinary norandrosterone traces by gas chromatography combustion isotope ratio mass spectrometry

On the one hand, 19-norandrosterone (NA) is the most abundant metabolite of the synthetic anabolic steroid 19-nortestosterone and related prohormones. On the other hand, small amounts are biosynthesized by pregnant women and further evidence exists for physiological origin of this compound. The World Anti-Doping Agency (WADA) formerly introduced threshold concentrations of 2 or 5 ng of NA per ml of urine to discriminate 19-nortestosterone abuse from biosynthetic origin. Recent findings showed however, that formation of NA resulting in concentrations in the range of the threshold levels might be due to demethylation of androsterone in urine, and the WADA 2006 Prohibited List has defined NA as endogenous steroid. To elucidate the endogenous or exogenous origin of NA, (13)C/(12)C-analysis is the method of choice since synthetic 19-nortestosterone is derived from C(3)-plants by partial synthesis and shows delta(13)C(VPDB)-values of around -28 per thousand. Endogenous steroids are less depleted in (13)C due to a dietary mixture of C(3)- and C(4)-plants. An extensive cleanup based on two high performance liquid chromatography cleanup steps was applied to quality control and doping control samples, which contained NA in concentrations down to 2 ng per ml of urine. (13)C/(12)C-ratios of NA, androsterone and etiocholanolone were measured by gas chromatography/combustion/isotope ratio mass spectrometry. By comparing delta(13)C(VPDB)-values of androsterone as endogenous reference compound with NA, the origin of NA in doping control samples was determined as either endogenous or exogenous.

Application of stable carbon isotope analysis to the detection of 17β-estradiol administration to cattle

The use of anabolic agents in food producing animals is prohibited within the EU since 1988 (96/22/EC directive). The control of the illegal use of natural steroid hormones in cattle is still an exciting analytical challenge as far as no definitive method and non-ambiguous analytical criteria are available. The ability of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to demonstrate the administration of 17beta-estradiol to bovine has been investigated in this paper. By comparison of 13C/12C isotopic ratio of main urinary estradiol metabolite, i.e. 17alpha-estradiol, with two endogenous reference compounds (ERCs), i.e. dehydroepiandrosterone (DHEA) and 5-androstene-3beta,17alpha-diol, the differentiation of estradiol metabolite origin, either endogenous or exogenous, has been proved to be achievable. After treatment, the delta(13)C(VPDB)-values of 17alpha-estradiol reached -27 per thousand to -29 per thousand, whereas delta13CVPDB-values of DHEA remained between -13 per thousand and -20 per thousand depending on the diet, maize and grass, respectively. A significant difference of delta13CVPDB between ERCs and 17alpha-estradiol was measurable over a period of 2 weeks after estradiol ester administration to the animal.