Growth Hormone Abuse In Sport Research Articles

Metabolic Consequences of Anabolic Steroids, Insulin, and Growth Hormone Abuse in Recreational Bodybuilders: Implications for the World Anti-Doping Agency Passport

BackgroundHormonal doping in recreational sports is a public-health concern. The World Anti-Doping Agency (WADA) promoted the creation of the Athlete Biological Passport, aiming to monitor athlete’s biological variables over time to facilitate indirect detection of doping. Detection tests for anabolic androgenic steroids (AAS) and growth hormone (GH) are available while insulin abuse cannot be revealed. We have determined in recreational bodybuilders the metabolic effects associated with different patterns of hormone abuse. All analyses were conducted using Statistical Package for Social Sciences (SPSS) 21.0 software (SPSS Chicago, IL).ResultsWe have assessed plasma concentrations of selected metabolic markers and fatty acid content in erythrocyte membranes of 92 male bodybuilders and in 45 healthy controls. Hormonal abuse was identified by anonymous questionnaires. 43% (%) of recruited bodybuilders regularly abused hormones, i.e., anabolic androgenic steroids (95%) often associated with GH (30%) and/or insulin (38%). HDL-cholesterol was lower in insulin and/or GH abusers. Alanine (ALT) and aspartic (AST) transaminases were greater in hormone abusing bodybuilders than in non-doping bodybuilders and controls. Insulin doping was selectively associated with increased plasma ALT-to-AST ratio. In erythrocyte membranes, elongase activity (i.e., stearic-to-palmitic ratio) was lower in insulin and/or growth hormone doping, whereas increased Δ-9 desaturase activity (i.e., palmitoleic-to-palmitic ratio) was selectively associated with insulin doping.ConclusionsIn conclusion, our study demonstrates that insulin and GH abuse are characterized by multiple alterations of specific metabolic markers. Although further studies are needed to test whether longitudinal monitoring of selected metabolic marker such as muscle contraction time, HDL levels, ALT-AST ratio as well as the activities of selected enzymes (e.g. Δ-9 desaturase and elongase), could contribute to the detection of insulin and GH abuse in sport.

Plasma biomarker proteins for detection of human growth hormone administration in athletes

Human growth hormone (GH) is a naturally occurring hormone secreted by the pituitary gland with anabolic and growth-promoting activities. Since an increased availability of recombinant GH (rGH) for the treatment of GH-deficient patients, GH has been abused in sports and it is prohibited. “GH-isoform” and “biomarkers” tests are currently available for detection of GH abuse in sports, however both methods suffer from shortcomings. Here, we report on a proteomic approach to search for novel protein biomarkers associated with rGH administration in non-elite athletes. In this study, participants received either placebo or rGH for 8 weeks, and were followed over a 6-week washout period. We used 2-D DIGE and iTRAQ LC-MS/MS analyses to expose rGH-dependent marker proteins. Eight rGH-dependent plasma proteins namely apolipoproptein-L1, alpha-HS-glycoprotein, vitamin D-binding protein, afamin, insulin-like growth factor-binding protein-3, insulin-like growth factor-binding protein-ALS, lumican and extracellular matrix proteins 1 were identified. Apolipoprotein L1 and alpha-HS-glycoprotein were validated by Western blots to confirm their identities and expression patterns in rGH- and placebo-treated subject cohorts. Independent confirmation of these putative GH-responsive biomarkers would be of value for clinical practices and may have sports anti-doping utility.

Running ahead of doping: analytical advances and challenges faced by modern laboratories ahead of Rio 2016.

Running ahead of doping: analytical advances and challenges faced by modern laboratories ahead of Rio 2016.

Analytical challenges and solutions in doping control: a perspective from the Swedish Doping Control Laboratory.

BioanalysisVol. 8, No. 8 CommentaryAnalytical challenges and solutions in doping control: a perspective from the Swedish Doping Control LaboratoryMagnus EricssonMagnus Ericsson*Author for correspondence: E-mail Address: dopinglab@karolinska.se Doping Control Laboratory, Clinical Pharmacology, Karolinska University Hospital, Stockholm, SE 141 86, SwedenSearch for more papers by this authorPublished Online:23 Mar 2016https://doi.org/10.4155/bio-2016-0037AboutSectionsView ArticleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinkedInReddit View articleKeywords: GC–MS/MSLC-HRMSOlympic GamesReferences1 World Anti-Doping Agency. The Prohibited List 2016. www.wada-ama.org.Google Scholar2 World Anti-Doping Agency. International Standard for Laboratories (ISL). www.wada-ama.org.Google Scholar3 Badoud F, Grataa E, Perrenoud L et al. Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography–quadrupole time-of-flight mass spectrometry I. Screening analysis. J. Chromatogr. A 1216, 4423–4433 (2009).Crossref, Medline, CAS, Google Scholar4 Girón A J, Deventer K, Roels K, Van Eenoo P. Development and validation of an open screening method for diuretics, stimulants and selected compounds in human urine by UHPLC–HRMS for doping control. Anal. Chim. Acta 721, 137–146 (2012).Crossref, Medline, Google Scholar5 World Anti-Doping Agency. The Technical document TD2016EAAS. www.wada-ama.org.Google Scholar6 Thörngren JO, Östervall F, Garle M. A high-throughput multicomponent screening method for diuretics, masking agents, central nervous system (CNS) stimulants and opiates in human urine by UPLC–MS/MS. J. Mass Spectrom. 43, 980–992 (2008).Crossref, Medline, Google Scholar7 World Anti-Doping Agency. The Technical document TD2015MRPL. www.wada-ama.org.Google Scholar8 Sottas PE, Saugy M, Saudan C. Endogenous steroid profiling in the athlete biological passport. Endocrinol. Metab. Clin. North Am. 39, 59 (2011).Crossref, Google Scholar9 Boscha J, Such-Sanmartína G, Seguraa J, Gutiérrez-Gallego B R. Tracking growth hormone abuse in sport: performance of marker proteins in a controlled setting. Anal. Chim. Acta 745, 118–123 (2012).Crossref, Medline, Google Scholar10 Van Renterghem P, Van Eenoo P, Sottas PE, Saugy M, Delbeke F. A pilot study on subject-based comprehensive steroid profiling: novel biomarkers to detect testosterone misuse in sports. Clin. Endocrinol. (Oxf.) 75(1), 134–140 (2011).Crossref, Medline, CAS, Google Scholar11 Schänzer W, Guddat S, Thomas A, Opfermann G, Geyer H, Thevis M. Expanding analytical possibilities concerning the detection of stanozolol misuse by means of high resolution/high accuracy mass spectrometric detection of stanozolol glucuronides in human sports drug testing. Drug Test. Anal. 5, 11–12 (2013).Crossref, Google Scholar12 Sobolevsky T, Rodchenkov G. Detection and mass spectrometric characterization of novel long-term dehydrochloromethyltestosterone metabolites in human urine. J. Steroid Biochem. Mol. Biol. 128(3–5), 121–127 (2012).Crossref, Medline, CAS, Google Scholar13 Buisson C, Marchand A, Bailloux I, Lahaussois A, Martin L, Molina A. Detection by LC–MS/MS of HIF stabilizer FG-4592 used as a new doping agent: Investigation on a positive case. J. Pharm. Biomed. Anal. 121, 181–187 (2016).Crossref, Medline, CAS, Google Scholar14 Leuenberger N, Barras L, Nicoli R et al. Hepcidin as a new biomarker for detecting autologous blood transfusion. Am. J. Hematol. doi: 10.1002/ajh.24313 (2016) (Epub ahead of print).Crossref, Medline, Google Scholar15 Malm C, Frangsmyr L, Holmberg S. Detection of autologous blood transfusion by proteomics: screening to find unique biomarkers. www.wada-ama.org/en/resources/science-medicine/detection-of-autologous-blood-transfusion-by-proteomicsscreening-to-find.Google ScholarFiguresReferencesRelatedDetailsCited ByCubosomic Supramolecular Solvents: Synthesis, Characterization, and Potential for High-Throughput Multiclass Testing of Banned Substances in Urine22 February 2022 | Analytical Chemistry, Vol. 94, No. 9Interest of HRMS systems in analytical toxicology: Focus on doping productsToxicologie Analytique et Clinique, Vol. 8A comprehensive study on the performance of different retention mechanisms in sport drug testing by liquid chromatography tandem mass spectrometryJournal of Chromatography B, Vol. 1178Supramolecular solvents in microextraction techniquesTwenty years of supramolecular solvents in sample preparation for chromatography: achievements and challenges ahead23 March 2020 | Analytical and Bioanalytical Chemistry, Vol. 412, No. 24Development and validation of a UHPLC-HRMS method for the simultaneous determination of the endogenous anabolic androgenic steroids in human serumJournal of Chromatography A, Vol. 1613Comprehensive analysis by liquid chromatography Q-Orbitrap mass spectrometry: Fast screening of peptides and organic molecules18 April 2018 | Journal of Mass Spectrometry, Vol. 53, No. 6 Vol. 8, No. 8 Follow us on social media for the latest updates Metrics Downloaded 162 times History Published online 23 March 2016 Published in print April 2016 Information© Future Science LtdKeywordsGC–MS/MSLC-HRMSOlympic GamesFinancial & competing interests disclosureThe author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.No writing assistance was utilized in the production of this manuscript.PDF download

Intra-individual variation of GH-dependent markers in athletes: Comparison of population based and individual thresholds for detection of GH abuse in sports

The GH-2000 discriminant functions, using insulin-like growth factor I (IGF-I) and the N-terminal propeptide of type III procollagen (PIIINP), enabled the detection of growth hormone (GH) doping despite the broad inter-individual normal range of both peptides. The sensitivity of the discriminant function-based methodology may perhaps be further increased in future by applying individual athlete profiles. The purpose of the present study was to evaluate the intra-individual variability of IGF-I, PIIINP and the GH-2000 scores in athletes. For this purpose a total of eight blood samples were taken from each of fifty male and female elite athletes over a period of up to 18 months. The IGF-I and PIIINP levels, we found, lay predominantly within the reference range for elite athletes. The intra-individual variability for IGF-I ranged between 6 and 26%, while that for PIIINP ranged between 6 and 33%. The intra-individual variations of both parameters were higher in female than in male subjects and were found to be mostly moderate. We found that the intra-individual variations of the GH-2000 test scores, expressed as CV, ranged from 4 to 36% and were in most of the subjects markedly smaller than the inter-individual variation. Individual cut-offs for the GH-2000 scores would be lower than population based ones in most of the cases.

Quantification of insulin-like growth factor-1 in dried blood spots for detection of growth hormone abuse in sport

There is significant evidence that athletes are using recombinant human growth hormone (rhGH) to enhance performance, and its use is banned by the World Anti-Doping Agency and professional sports leagues. Insulin-like growth factor-1 (IGF-1) is the primary mediator of growth hormone action and is used as a biomarker for the detection of rhGH abuse. The current biomarker-based method requires collection and expedited shipment of venous blood which is costly and may decrease the number of tests performed. Measurement of GH biomarkers in dried blood spots (DBS) would considerably simplify sample collection and shipping methods to allow testing of a greater number of samples regardless of location. A method was developed to quantify intact IGF-1 protein in DBS by liquid chromatography-tandem mass spectrometry. A step-wise acid-acetonitrile extraction was optimized to achieve a sensitive assay with a lower limit of quantification of 50 ng/mL. IGF-1 remained stable at room temperature for up to 8 days, which would allow shipment of DBS cards at ambient temperature. In a comparison between plasma concentrations of IGF-1 and concentrations measured from venous and finger prick DBS, there was good correlation and agreement, r(2) of 0.8551 and accuracy of 86-113 % for venous DBS and r(2) of 0.9586 and accuracy of 89-122 % for finger prick DBS. The method is intended for use as a rapid screening method for IGF-1 to be used in the biomarker method of rhGH abuse detection.

Tracking growth hormone abuse in sport: Performance of marker proteins in a controlled setting

Human growth hormone (hGH) abuse in sport is a challenge at present. The current strategy used, known as direct method, is based on the quantification of hGH variants in serum. An alternative strategy, known as indirect method, focuses on serum markers such as insulin-like growth factor I (IGF-I) and procollagen type III N-terminal propeptide (P-III-NP). The indirect method allows a longer window of detection (WOO) of hGH abuse. To evaluate the performance of the indirect method, in parallel to the direct method, a clinical trial with recombinant hGH (rhGH) was conducted on healthy male subjects during 7 days (0.026mg−1kg−1person−1day−1). The data were fit to the discriminant formula proposed in the previously published GH-2000 project. The low sensitivity of the scores, judged from the high number of false negative outcomes, imposed a new discriminant analysis, standarised using local population subjects demographically similar to the ones of the study. The sensitivity of the method significantly increased, highlighting the importance of the standardisation. The indirect method allowed extended window of opportunity (WOO), although two false positive evaluations were observed derived from elevated basal IGF-I and P-III-NP concentrations stressing the need for an independent confirmation method. When direct and indirect methods were combined the best selectivity and sensitivity were achieved.

Tracking growth hormone abuse in sport: A comparison of distinct isoform-based assays

Detecting recombinant human growth hormone (rhGH) abuse in sport remains one of the major challenges in doping control. We have compared two different approaches to detect the hGH (human growth hormone) abuse. The first measures the concentrations of the 22kDa hGH isoform (rec assay) and pituitary derived isoforms (pit assay) and a ratio rec/pit is obtained. The second measures the concentrations of 22 and 20kDa hGH isoforms and also a ratio 22/20kDa is derived.Using a single set (nine healthy male subjects, 7 days, 0.026mg/kg/day of rhGH, 2 week wash out period) both approaches were compared. To quantify the agreement between the immunoassays, B.A. (Bland–Altman) analysis and P.r. (Pearson correlation) were used. To fully understand the assay readings, all relevant antibodies were characterised by surface plasmon resonance (SPR).In either approach the ratio numerator produces similar results and the denominator determines both signal-amplitude and time-frame of possible application. The rec vs pit approach displays a higher distinctive capacity to detect hGH abuse but the complex binding properties of the capture antibodies make it very difficult to evaluate the precise contributions of the individual hGH variants to the assay result. In the 22 vs 20 approach, the 20kDa hGH concentration measures determine its applicability.Both approaches are based on a different principle, should be preferably applied within 24h after rhGH administration, and are perfectly comparable given the results obtained. The reduced time frame of application indicates that their principle application should be preferably in an out-of-competition setting.

The use of growth hormone (GH)‐dependent markers in the detection of GH abuse in sport: Physiological intra‐individual variation of IGF‐I, type 3 pro‐collagen (P‐III‐P) and the GH‐2000 detection score

Growth Hormone is abused by athletes for its lipolytic and anabolic properties. Its use is prohibited by the World Anti-Doping Agency. The GH-2000 project developed a methodology to detect its abuse using the concentrations of two GH-dependent biomarkers, IGF-I and type 3 procollagen (P-III-P). The sensitivity of this method may be improved by considering intra-individual variability. The aim of this study was to examine the intra-individual variability of IGF-I, P-III-P and the GH-2000 score. IGF-I, P-III-P and GH-2000 score were evaluated in four longitudinal studies involving 303 elite and 78 amateur athletes. Samples were collected over a period of up to 12 months from a total of 238 men and 143 women aged between 17 and 53 years (mean 24.2). The four studies showed good agreement with no apparent difference in within-individual variation between amateur and elite athletes. The intra-individual variability for IGF-I ranged between 14-16% while the variability for P-III-P was 7-18%. No athlete tested positive for growth hormone during any of the studies. The overall mean intra-individual variability of the GH-2000 score was less than 0.6 units in all studies. The high stability of marker levels suggests that concentrations are largely genetically determined. Adopting a test based on the concept of an athlete's 'passport' or 'profiling' would take advantage of this and most likely increase the sensitivity of the test. These data also provide strong evidence that a positive test result for GH abuse would not occur as a result of chance variability.

The use of growth hormone (GH)-dependent markers in the detection of GH abuse in sport: Physiological intra-individual variation of IGF-I, type 3 pro-collagen (P-III-P) and the GH- 2000 detection score: Authors’ response

The use of growth hormone (GH)-dependent markers in the detection of GH abuse in sport: Physiological intra-individual variation of IGF-I, type 3 pro-collagen (P-III-P) and the GH- 2000 detection score: Authors’ response

The use of growth hormone (GH)-dependent markers in the detection of GH abuse in sport: Physiological intra-individual variation of IGF-I, type 3 pro-collagen (P-III-P) and the GH-2000 detection score

The use of growth hormone (GH)-dependent markers in the detection of GH abuse in sport: Physiological intra-individual variation of IGF-I, type 3 pro-collagen (P-III-P) and the GH-2000 detection score

The history of doping and growth hormone abuse in sport

The earliest records of doping in sport come from the Ancient Olympics games when athletes are reported to have taken figs to improve their performance. With the advent of modern pharmacology in the 19th century, many athletes began to experiment with cocktails of drugs to improve strength and overcome fatigue. As this practice was not illegal, there are good records of the lengths athletes would go to in order to win. Alongside the benefits, came the dangers and following several fatalities, a code to ban performance enhancing drugs was gradually developed. Growth hormone was first isolated from the human pituitary gland in the 1950s. Its anabolic effects were soon recognised and athletes had begun to abuse it by the early 1980s, at least a decade before it was used therapeutically by adult endocrinologists. A number of high profile athletes have admitted using growth hormone. Detection of its abuse has been challenging and the lack of an effective test has undoubtedly encouraged its abuse. Only now are methodologies being developed that should stem this tide.

P-82 The physiological variability of insulin growth factor I and procollagen type III in amateur and elite athletes: implications in detecting growth hormone abuse in sports

P-82 The physiological variability of insulin growth factor I and procollagen type III in amateur and elite athletes: implications in detecting growth hormone abuse in sports

Quantification of human insulin‐like growth factor‐1 and qualitative detection of its analogues in plasma using liquid chromatography/electrospray ionisation tandem mass spectrometry

Human insulin-like growth factor-1 (IGF-1) is a peptide hormone that acts as a mediator of most of the somatotropic effects of growth hormone (GH). Therefore, it is supposed to be a biomarker indicating GH abuse in sports as well as diseases associated with a change in IGF-1 plasma concentration. It can be applied locally by injection to increase total protein and DNA content in tissues such as skeletal muscle--a highly desirable effect in various sports disciplines. In order to improve its growth-promoting properties, the primary structure of IGF-1 has been modified, yielding analogues such as des(1-3)IGF-1 and LONGR3IGF-1, which show a considerably reduced affinity to the respective binding proteins in plasma and, thus, an increased bioavailability at target tissues. Due to their capability to enhance performance, IGF-1 and its analogues belong to the prohibited list of the World Anti-Doping Agency. Hence, it was necessary to develop a reliable assay for the quantification of human IGF-1 as well as the detection of its derivatives. Immunoaffinity isolation and purification from 60 microL of plasma followed by liquid chromatography/electrospray ionisation tandem mass spectrometry enabled the unequivocal determination of all target analytes. Diagnostic product ions were characterised utilising an Orbitrap mass spectrometer with high resolution/high accuracy properties and employed for triple quadrupole MS/MS analysis. The described assay provided lower limits of detection (LLODs) between 20 and 50 ng/mL, recovery rates between 34-43% and a precision <15% at the LLOD as well as higher concentration levels. In order to prove the applicability of the developed assay, human plasma samples were analysed and the results were compared with the values obtained from a commercially available immunoradiometric assay (IRMA). Four of six samples resulted in concentration ratios with good correlation between both assays, whereas the absolute concentrations were lower for the presented procedure.

Technology Insight: detecting growth hormone abuse in athletes

Athletes recognized the performance-enhancing potential of human growth hormone when it became available for treatment of short stature in growth-retarded children. Although no controlled clinical studies have demonstrated a significant benefit in highly trained adults with normal pituitary function, the practice of doping increased with the introduction of recombinant human growth hormone. Evidence of widespread abuse has been gathered by police and customs authorities or provided by former athletes. It has been difficult to develop a test to prove the administration of exogenous growth hormone in athletes because of its specific physiological and biochemical properties. Significant progress has only recently been made, particularly via two differing approaches. The 'marker approach' utilizes characteristic changes in concentrations of pharmacodynamic end points of growth hormone action, for example serum concentrations of insulin-like growth factor I and factors related to bone and soft tissue turnover. The 'isoform approach' detects changes in the molecular isoform composition of circulating growth hormone evoked by the administration of exogenous recombinant growth hormone. The isoform approach was applied at the Olympic Games in Athens in 2004 and in Turin in 2006. Used in a complementary way in an out-of-competition setting, these methods are a powerful tool with which to detect growth hormone abuse in sports.

Validation of the growth hormone (GH)-dependent marker method of detecting GH abuse in sport through the use of independent data sets

Context The detection of exogenously administered growth hormone (GH) poses a formidable challenge but a detection method based on the measurement of two GH-dependent markers, IGF-I and type 3 pro-collagen (P-III-P) has been proposed. The measurement of multiple markers in conjunction with discriminant functions can improve the sensitivity and specificity of detection compared with single marker analysis. Objective To provide further validation of the GH-dependent marker approach. Design Analysis of discriminant function scores for GH detection on independent datasets. Setting Two independent (GH-2000 and Kreischa) double blind, placebo controlled, hGH administration studies. Subjects Healthy active male volunteers. Intervention GH-2000 proposed a discriminant function involving IGF-I and P-III- P while the Kreischa function involved IGF-I, P-III-P and IGFBP-3. After adjustment for assay differences the formulae were applied to the other dataset. Outcome measures Ability to detect GH use in independent datasets using a predefined specificity of approximately 1 in 10 000. Results The GH-2000 formula was able to detect 90% of those receiving GH in the Kreischa study at one or more time points during the study period. This sensitivity was similar to that obtained on the original GH-2000 dataset. The Kreischa formula correctly identified 41% of individuals receiving GH in the GH-2000 study. Conclusions The study provides further validation that the test proposed by GH-2000 based on IGF-I and P-III-P concentrations can be used to detect subjects receiving exogenous GH.

Detection of growth hormone abuse in sport

Objective To develop a test for GH abuse in sport. Design A double blind placebo controlled study of one month’s GH administration to 102 healthy non-competing but trained subjects. Blood levels of nine markers of GH action were measured throughout the study and for 56 days after cessation of GH administration. Blood samples were also taken from 813 elite athletes both in and out of competition. Results GH caused a significant change in the nine measured blood markers. Men were more sensitive to the effects of GH than women. IGF-I and N-terminal extension peptide of procollagen type III were selected to construct formulae which gave optimal discrimination between the GH and placebo groups. Adjustments were made to account for the fall in IGF-I and P-III-P with age and the altered distribution seen in elite athletes. Using a cut-off specificity of 1:10,000 these formulae would allow the detection of up to 86% of men and 60% of women abusing GH at the doses used in this study. Conclusions We report a methodology that will allow the detection of GH abuse. This will provide the basis of a robust and enforceable test identifying those who are already cheating and provide a deterrent to those who may be tempted to do so.

Growth Hormone (GH) Effects on Bone and Collagen Turnover in Healthy Adults and Its Potential as a Marker of GH Abuse in Sports: A Double Blind, Placebo-Controlled Study

Growth Hormone (GH) Effects on Bone and Collagen Turnover in Healthy Adults and Its Potential as a Marker of GH Abuse in Sports: A Double Blind, Placebo-Controlled Study

Responses of the Growth Hormone (GH) and Insulin-Like Growth Factor Axis to Exercise, GH Administration, and GH Withdrawal in Trained Adult Males: A Potential Test for GH Abuse in Sport

Responses of the Growth Hormone (GH) and Insulin-Like Growth Factor Axis to Exercise, GH Administration, and GH Withdrawal in Trained Adult Males: A Potential Test for GH Abuse in Sport

Responses of the growth hormone (GH) and insulin-like growth factor axis to exercise, GH administration, and GH withdrawal in trained adult males: a potential test for GH abuse in sport.

GH abuse by elite athletes is currently undetectable. To define suitable markers of GH doping, we assessed the effects of acute exercise, GH administration, and GH withdrawal on the GH/insulin-like growth factor (IGF) axis in athletic adult males. Acute endurance-type exercise increased serum GH, GH-binding protein (GHBP), total IGF-I, IGF-binding protein (IGFBP)-3, and acid-labile subunit (ALS), each peaking at the end of exercise. IGFBP-1 increased after exercise was completed. Free IGF-I did not change with exercise. Recombinant human GH treatment (0.15 IU/kg x day) for 1 week increased serum total IGF-I, IGFBP-3, and ALS, exaggerating the responses to exercise. IGFBP-2 and IGFBP-1 were trivially suppressed. After GH withdrawal, the GH response to identical exercise was suppressed. Total IGF-I, IGFBP-3, and ALS returned to baseline over 3-4 days. In summary, 1) acute exercise transiently increased all components of the IGF-I ternary complex, possibly due to mobilization of preformed intact complexes; 2) GH pretreatment augmented the exercise-induced changes in ternary complexes; 3) postexercise IGFBP-1 increments may protect against delayed onset hypoglycemia; 4) serum total IGF-I, IGFBP-3, and ALS may be suitable markers of GH abuse; and 5) differences in disappearance times altered the sensitivity of each marker for detecting GH abuse.