Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Sports Act Living ; 4: 954479, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928963

RESUMO

The hematological module of the Athlete Biological Passport (ABP) aims to reveal blood doping indirectly by looking at selected biomarkers of doping over time. For Anti-Doping Organizations (ADOs), the ABP is a vital tool in the fight against doping in sports through improved target testing and analysis, investigations, deterrence, and as indirect evidence for use of prohibited methods or substances. The physiological characteristics of sport disciplines is an important risk factor in the overall risk assessment and when implementing the hematological module. Sharing of experiences with implementing the hematological ABP between ADOs is key to further strengthen and extend its use. In this study, we present 10 years of experience with the hematological ABP program from the perspectives of a National ADO with special attention to sport disciplines' physiological characteristics as a potential risk factor for blood doping. Not surprisingly, most samples were collected in sport disciplines where the aerobic capacity is vital for performance. The study highlights strengths in Anti-Doping Norway's testing program but also areas that could be improved. For example, it was shown that samples were collected both in and out of season in a subset of the data material that included three popular sports in Norway (Cross-Country Skiing, Nordic Combined, and Biathlon), however, from the total data material it was clear that athletes were more likely to be tested out of competition and on certain days of the week and times of the day. The use of doping control officers with a flexible time schedule and testing outside an athlete's 60 min time-slot could help with a more even distribution during the week and day, and thus reduce the predictability of testing. In addition to promoting a discussion on testing strategies, the study can be used as a starting point for other ADOs on how to examine their own testing program.

2.
J Clin Endocrinol Metab ; 106(3): 697-707, 2021 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-33274381

RESUMO

CONTEXT: Little is known about how exogenous testosterone (T) affects the steroid profile in women. More knowledge would give the antidoping community keys as to how to interpret tests and detect doping. OBJECTIVE: This work aimed to investigate the steroid profile in serum and urine in young healthy women after T administration. METHODS: In a randomized, double-blind, placebo-controlled study, 48 healthy young women were assigned to daily treatment with T cream (10 mg) or placebo (1:1) for 10 weeks. Urine and blood were collected before and at the end of treatment. Serum steroids were analyzed with liquid chromatography-tandem mass spectrometry, and urine levels of T, epitestosterone (E), and metabolites included in the Athlete Biological Passport (ABP) were analyzed with gas chromatography-tandem mass spectrometry. RESULTS: In serum, T and dihydrotestosterone levels increased, whereas sex hormone-binding globulin and 17-hydroxyprogesterone decreased after T treatment as compared to placebo. In urine, T and 5α-androstanediol increased in the T group. The median T increase in serum was 5.0-fold (range, 1.2-18.2) and correlated to a 2.2-fold (range, 0.4-14.4) median increase in T/E in urine (rs = 0.76). Only 2 of the 24 women receiving T reached the T/E cutoff ratio of 4, whereas when the results were added to the ABP, 6 of 15 participants showed atypically high T/E (40%). In comparison, 22/24 women in the T group increased serum T more than 99.9% of the upper confidence interval of nontreated values. CONCLUSION: It seems that the T/E ratio is not sufficient to detect exogenous T in women. Serum total T concentrations could serve as a complementary marker of doping.


Assuntos
Esteroides/sangue , Esteroides/urina , Testosterona/administração & dosagem , Adolescente , Adulto , Atletas , Análise Química do Sangue/métodos , Cromatografia Líquida , Dopagem Esportivo , Método Duplo-Cego , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Voluntários Saudáveis , Humanos , Placebos , Esteroides/metabolismo , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem , Testosterona/sangue , Testosterona/urina , Urinálise/métodos , Adulto Jovem
3.
Drug Test Anal ; 12(9): 1229-1240, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32497419

RESUMO

The interpretation of athlete biological passport (ABP) is strengthened by understanding the natural fluctuations in its biological parameters. Here we have assessed the influence of the menstrual cycle on the hematological module of the ABP. Seventeen women with regular menses were included. Blood samples were collected once a week for two consecutive cycles and analyzed for hematological parameters. Menstrual phases were hormonally determined. The intra-individual variation in the hematological parameters was similar between the two cycles. Reticulocyte percentage was significantly lower in the follicle phase (median 0.95%) than in the ovulatory (median 1.10%) and luteal phases (median 1.16%), P = 0.006, whereas no differences were found in hemoglobin concentration, hematocrit, red blood cell count, or red blood cell indices. When the values were entered into the ABP model, findings outside the program-calculated individual thresholds were identified in two participants. One woman showed an atypical low OFF-score in the last sample collected, mainly because of increased reticulocyte percentage. This was likely a response to treated insufficient iron stores. One woman displayed an atypical hemoglobin value at the lower limit 2 weeks after ovulation, which was likely due to fluctuations in plasma volume. In conclusion, the ABP parameters in general are stable throughout the menstrual cycle. Significant differences between the menstrual phases were found in reticulocytes; however, the variation was not related to findings outside the individual thresholds, except in one individual. Moreover, our results highlight the importance of having information about iron supplementation available when evaluating hematological passports.


Assuntos
Atletas , Biomarcadores/sangue , Ciclo Menstrual/fisiologia , Reticulócitos/citologia , Adolescente , Adulto , Estudos de Coortes , Dopagem Esportivo , Feminino , Hematócrito , Hemoglobinas/análise , Humanos , Estudos Longitudinais , Volume Plasmático/fisiologia , Adulto Jovem
4.
Drug Test Anal ; 12(6): 720-730, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32052600

RESUMO

The steroidal module of the Athlete Biological Passport (ABP) aims to detect doping with endogenous steroids, e.g. testosterone (T), by longitudinally monitoring several biomarkers. These biomarkers are ratios combined into urinary concentrations of testosterone and metabolically related steroids. However, it is evident after 5 years of monitoring steroid passports that there are large variations in the steroid ratios complicating its interpretation. In this study, we used over 11000 urinary steroid profiles from Swedish and Norwegian athletes to determine both the inter- and intra-individual variations of all steroids and ratios in the steroidal passport. Furthermore, we investigated if the inter-individual variations could be associated with factors such as gender, type of sport, age, time of day, time of year, and if the urine was collected in or out of competition. We show that there are factors reported in today's doping tests that significantly affect the steroid profiles. The factors with the largest influence on the steroid profile were the type of sport classification that the athlete belonged to as well as whether the urine was collected in or out of competition. There were also significant differences based on what time of day and time of year the urine sample was collected. Whether these significant changes are relevant when longitudinally monitoring athletes in the steroidal module of the ABP should be evaluated further.


Assuntos
Dopagem Esportivo/métodos , Esteroides/urina , Adulto , Envelhecimento , Anabolizantes/urina , Biomarcadores/urina , Ritmo Circadiano , Feminino , Humanos , Estudos Longitudinais , Masculino , Noruega , Estações do Ano , Caracteres Sexuais , Esportes , Detecção do Abuso de Substâncias , Suécia , Coleta de Urina , Adulto Jovem
5.
Med Sci Sports Exerc ; 51(2): 288-298, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30188363

RESUMO

PURPOSE: To investigate the effects of blood flow-restricted resistance exercise (BFRRE) on myofiber areas (MFA), number of myonuclei and satellite cells (SC), muscle size and strength in powerlifters. METHODS: Seventeen national level powerlifters (25 ± 6 yr [mean ± SD], 15 men) were randomly assigned to either a BFRRE group (n = 9) performing two blocks (weeks 1 and 3) of five BFRRE front squat sessions within a 6.5-wk training period, or a conventional training group (Con; n = 8) performing front squats at 60%-85% of one-repetition maximum (1RM). The BFRRE consisted of four sets (first and last set to voluntary failure) at ~30% of 1RM. Muscle biopsies were obtained from m. vastus lateralis (VL) and analyzed for MFA, myonuclei, SC and capillaries. Cross-sectional areas (CSA) of VL and m. rectus femoris were measured by ultrasonography. Strength was evaluated by maximal voluntary isokinetic torque (MVIT) in knee extension and 1RM in front squat. RESULTS: BFRRE induced selective increases in type I MFA (BFRRE: 12% vs Con: 0%, P < 0.01) and myonuclear number (BFRRE: 18% vs Con: 0%, P = 0.02). Type II MFA was unaltered in both groups. BFRRE induced greater changes in VL CSA (7.7% vs 0.5%, P = 0.04), which correlated with the increases in MFA of type I fibers (r = 0.81, P = 0.02). No group differences were observed in SC and strength changes, although MVIT increased with BFRRE (P = 0.04), whereas 1RM increased in Con (P = 0.02). CONCLUSIONS: Two blocks of low-load BFRRE in the front squat exercise resulted in increased quadriceps CSA associated with preferential hypertrophy and myonuclear addition in type 1 fibers of national level powerlifters.


Assuntos
Fibras Musculares de Contração Lenta/citologia , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/irrigação sanguínea , Treinamento Resistido/métodos , Adulto , Contagem de Células , Núcleo Celular , Feminino , Humanos , Masculino , Microcirculação , Fibras Musculares de Contração Lenta/fisiologia , Músculo Esquelético/diagnóstico por imagem , RNA/metabolismo , Fluxo Sanguíneo Regional , Células Satélites de Músculo Esquelético/citologia , Ultrassonografia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...