Skip to main content

Advertisement

Log in

An altered hormonal profile and elevated rate of bone loss are associated with low bone mass in professional horse-racing jockeys

  • Original article
  • Published:
Journal of Bone and Mineral Metabolism Aims and scope Submit manuscript

Abstract

Horse-racing jockeys are a group of weight-restricted athletes, who have been suggested as undertaking rapid and extreme weight cycling practices in order to comply with stipulated body-mass standards. The aim of this study was to examine bone mass, turnover and endocrine function in jockeys and to compare this group with age, gender and body mass index matched controls. Twenty male professional jockeys and 20 healthy male controls participated. Dual energy X-ray absorptiometry scans and early morning fasting blood and urine samples were used to measure bone mass, turnover and a hormonal profile. Total body bone mineral density (BMD) was significantly lower in jockeys (1.143 ± 0.05 vs. 1.27 ± 0.06 g cm−3, p < 0.01). Bone resorptive activity was elevated in the jockey group as indicated by significantly higher urinary NTx/creatinine (76.94 ± 29.52 vs. 55.9 ± 13.9 nmol mmol−1, p < 0.01), resulting in a significantly negative uncoupling index between bone resorption and formation. Sex hormone binding globulin (SHBG) levels were significantly higher in jockeys (41.21 ± 9.77 vs. 28.24 ± 9.98 nmol L−1, p < 0.01) with a lower percentage of bioavailable testosterone (48.89 ± 7.38 vs. 59.18 ± 6.74 %, p < 0.01). SHBG and insulin-like growth factor-1 were independent predictors of total body and femoral neck BMD, respectively (p < 0.05). In conclusion, it appears that professional jockeys have an elevated rate of bone loss and reduced bone mass that appears to be associated with disrupted hormonal activity. It is likely that this may have occurred in response to the chronic weight cycling habitually experienced by this group.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Dolan E, O’Connor H, O’Loughlin G, McGoldrick A, Warrington G (2011) Nutritional, lifestyle and weight-control practices of professional jockeys. J Sports Sci 29:791–799

    Article  PubMed  Google Scholar 

  2. Moore JM, Timperio AF, Crawford DA, Cameron-Smith D (2002) Weight management and weight loss strategies of professional jockeys. Int J Sport Nutr Exerc Metab 12:1–13

    PubMed  Google Scholar 

  3. Leydon MA, Wall C (2002) New Zealand jockeys’ dietary habits and their potential impact on health. Int J Sport Nutr Exerc 12:220–237

    CAS  Google Scholar 

  4. Warrington GD, Dolan E, McGoldrick A, McEvoy J, MacManus C, Griffin M, Lyons D (2009) Chronic weight control impacts on physiological function and bone health in elite jockeys. J Sports Sci 27:543–550

    Article  PubMed  Google Scholar 

  5. Dolan E, Crabtree N, McGoldrick A, Ashley DT, McCaffrey N, Warrington GD (2011) Weight regulation and bone mass: a comparison between professional jockeys, elite amateur boxers and age. gender and bmi matched controls. J Bone Miner Metab. doi:10.1007/s00774-001-0297-1

    PubMed  Google Scholar 

  6. Frost HM (2003) Bone’s Mechanostat: A 2003 Update. Anat Rec Part A 275:1081–1101

    Article  Google Scholar 

  7. Cure–Cure C, Capozza RF, Cointry GR, Meta M, Cure-Ramirez P, Ferretti JL (2005) Reference chart for the relationships between dual energy X-ray absorptiometry assessed bone mineral content and lean mass in 3,063 healthy men and premenopausal and postmenopausal women. Osteoporos Int 16:2095–2106

    Article  PubMed  Google Scholar 

  8. De Souza MJ, Williams NI (2004) Physiological aspects and clinical sequelae of energy deficiency and hypoestrogenism in exercising women. Human Reprod Update 10:433–448

    Article  Google Scholar 

  9. Loucks AB, Thuma JR (2003) Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. J Clin Endocrinol Metab 88:297–311

    Article  PubMed  CAS  Google Scholar 

  10. Haspolat K, Ece A, Gurkan F, Atamer Y, Tutanc M, Yolbas I (2007) Relationship between leptin, insulin, IGF-1 and IGFBP3 in children with energy malnutrition. Clin Biochem 40:201–205

    Article  PubMed  CAS  Google Scholar 

  11. Misra M, Miller KK, Bjornsen J, Hackman A, Aggarwal A, Chung J, Ott M, Herzog DB, Johnson ML, Klibanski A (2003) Alterations in growth hormone secretory dynamics in adolescent girls with anorexia nervosa and effects on bone metabolism. J Clin Endocrinol 88:5615–5623

    Article  CAS  Google Scholar 

  12. Solomon AM, Bouloux PMG (2006) Modifying muscle mass: the endocrine perspective. J Endocrinol 191:349–360

    Article  PubMed  CAS  Google Scholar 

  13. Proteau S, Pelle A, Collomp K, Benhamou L, Courteix D (2006) Bone density in elite judoists and effects of weight cycling on bone metabolic balance. Med Sci Sports Exerc 38:694–700

    Article  Google Scholar 

  14. Vermeulen A, Verdonck L, Kaufman JM (1999) A critical evaluation of simple methods for the estimation of free testosterone in serum. J Clin Endocrinol Metab 84:3666–3672

    Article  PubMed  CAS  Google Scholar 

  15. Boot AM, de Ridder MAJ, van der Sluis IM, van Slobbe I, Krenning EP, de Muinick Keizer-Schrama SMBF (2009) Peak bone mineral density, lean body mass and fractures. Bone 46:336–341

    Article  PubMed  Google Scholar 

  16. Kroger H, Kotaniemi A, Vainio P, Alhava E (1992) Bone densitometry of the spine and femur in children by dual energy X-ray absorptiometry. Bone Miner Bone Mineral 17:75–85

    Article  CAS  Google Scholar 

  17. Molgaard C, Thomsen BL, Prentice A, Cole TJ, Michaelsen KF (1997) Whole body bone mineral density in healthy children and adolescents. Arch Dis 76:9–15

    Article  CAS  Google Scholar 

  18. Prentice A, Parsons TJ, Cole TJ (1994) Uncritical use of bone mineral density in absorptiometry may lead to size-related artifacts in the identification of bone mineral determinants. Am J Clin Nutr 60:837–842

    PubMed  CAS  Google Scholar 

  19. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, Murad MH, Weaver CM, Endocrine Society (2011) Evaluation, treatment and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 96:1911–1930

    Article  PubMed  CAS  Google Scholar 

  20. Waller AE, Daniels JL, Weaver NL, Robinson P (2000) Jockey injuries in the United States. J Am Med Assoc 283:1326–1328

    Article  CAS  Google Scholar 

  21. Bass SL, Eser P, Daly R (2005) The effect of exercise and nutrition on the mechanostat. J Musculoskelet Neuronal Interact 5:239–254

    PubMed  CAS  Google Scholar 

  22. Ferry B, Duclos M, Burt L, Therre P, LeGall F, Jaffre C, Courteix C (2011) Bone geometry and strength adaptations to physical constraints inherent in different sports: comparison between elite female soccer players and swimmers. J Bone Miner Metab 29:342–351

    Article  PubMed  Google Scholar 

  23. Garnero P, Sornay-Rendu E, Claustrat B, Delmas PD (2000) Biochemical markers of bone turnover, endogenous hormones and the risk of fractures in postmenopausal women: the OFELY study. J Bone Miner Res 15:1526–1536

    Article  PubMed  CAS  Google Scholar 

  24. Mora S, Gilsanz V (2003) Establishment of peak bone mass. Endocrinol Metab Clin North Am 32:39–63

    Article  PubMed  Google Scholar 

  25. Hansen MA, Overgaard K, Riis BJ, Christiansen C (1991) Role of peak bone mass and bone loss in postmenopausal osteoporosis: 12 year study. BMJ 303:961–964

    Article  PubMed  CAS  Google Scholar 

  26. Waldron-Lynch F, Murray BF, Brady JJ, McKenna MJ, McGoldrick A, Warrington G, O’Loughlin G, Barragry JM (2009) High bone turnover in irish professional jockeys. Osteoporos Int 21:521–525

    Article  PubMed  Google Scholar 

  27. Iuliano Burns S, Wang XF, Ayton J, Jones G (2009) Skeletal and hormonal responses to sunlight deprivation in Antarctic expeditioners. Osteoporos Int 20:1523–1528

    Article  PubMed  CAS  Google Scholar 

  28. Ihle R, Loucks AB (2004) Dose response relationships between energy availability and bone turnover in young exercising women. J Bone Miner Res 19:1231–1240

    Article  PubMed  Google Scholar 

  29. Kahn SM, Hryb DJ, Nakhla AM, Romas NA (2002) Sex hormone binding globulin is synthesized in target cells. J Endocrinol 175:113–120

    Article  PubMed  CAS  Google Scholar 

  30. Khosla S, Melton LJ, Atkinson EJ, O’Fallon WM, Klee GG, Riggs BL (1998) Relationship of serum sex steroid levels and bone turnover markers with bone mineral density in men and women: a key role for bioavailable estrogen. J Clin Endocrinol Metab 83:2266–2274

    Article  PubMed  CAS  Google Scholar 

  31. Frystyk J, Delhanty PJD, Skjerbek C, Baxter RC (1999) Changes in the circulating IGF system during short term fasting and refeeding. Am J Physiol Endocrinol Metab 40:245–252

    Google Scholar 

  32. Rajaram S, Baylink DJ, Mohan S (1997) Insulin like growth factor binding proteins in serum and other biological fluids: regulation and functions. Endocr Rev 18:801–831

    Article  PubMed  CAS  Google Scholar 

  33. Aimaretti G, Corneli G, Di Somma C, Baldilli R, Gasco V, Rovere S, Migliaretti G, Colao A, Tamburrano G, Lombardi G, Chigo E, Camami F (2005) Different degrees of gh deficiency evidenced by GHRH + arginine test and IGF-1 levels in adults with pituitary disease. J Endocrinolol Invest 28:247–252

    CAS  Google Scholar 

  34. Holt RIG, Webb E, Pentecost C, Sonksen PH (2001) Aging and physical fitness are more important than obesity in determining exercise-induced generation of GH. J Clin Endocrinol Metab 86:5715–5720

    Article  PubMed  CAS  Google Scholar 

  35. Nindl BC, Pierce JR, Durkot MJ, Tuckow AP, Kennett MJ, Nieves JW, Cosman F, Alemany JA, Hymer WC (2008) Relationship between growth hormone in vivo bioactivity, the insulin like growth factor 1 system and bone mineral density in young, physically fit men and women. Growth Horm IGF Res 18:439–445

    Article  PubMed  CAS  Google Scholar 

  36. Rubin J, Ackert-Bicknell CL, Zhu L, Fan X, Murphy TC, Nanes MS, Marcus R, Holloway L, Beamer WG, Rosen CJ (2002) IGF-1 regulates osteoprotegerin (OPG) and receptor activator of nuclear factor-kB ligand in vitro and OPG in vivo. J Clin Endocrinol Metab 87:4273–4279

    Article  PubMed  CAS  Google Scholar 

  37. Ueland T (2004) Bone metabolism in relation to alterations in systemic growth hormone. Growth Horm IGF Res 14:404–417

    Article  PubMed  CAS  Google Scholar 

  38. Garnero P, Sornay E, Rendu E, Delmas PD (2000) Low serum IGF-1 and recurrence of osteoporotic fractures in postmenopausal women. Lancet 355:898–899

    Article  PubMed  CAS  Google Scholar 

  39. Sjogren KS, Sheng M, Moverare S, Liu JL, Wallenius K, Tornell J, Isaksson O, Jansson J, Mohan S, Ohlsson C (2002) Effects of liver derived insulin-like growth factor 1 on bone metabolism in mice. J Bone Miner Res 17:342–351

    Article  Google Scholar 

  40. Nattiv A, Loucks AB, Manore MM, Sunborn CF, Sundgot-Borgen J, Warren MP (2007) The female athlete triad: ACSM position stand. Med Sci Sports Exerc 39:1867–1882

    Article  PubMed  Google Scholar 

Download references

Acknowledgments

This research was supported by an unrestricted grant from the Irish Turf Club.

Conflict of interest

The authors have nothing to declare regarding any potential conflicts of interest which may be perceived as prejudicing the impartiality of the research reported.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Eimear Dolan.

About this article

Cite this article

Dolan, E., McGoldrick, A., Davenport, C. et al. An altered hormonal profile and elevated rate of bone loss are associated with low bone mass in professional horse-racing jockeys. J Bone Miner Metab 30, 534–542 (2012). https://doi.org/10.1007/s00774-012-0354-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00774-012-0354-4

Keywords

Navigation