title: High bone turnover in Irish professional jockeys.
abstract: CONCLUSIONS
  Professional jockeys are routinely exposed to high impact trauma and sustain fractures frequently. We found that jockeys restrict their caloric intake in order to maintain regulation weights, and that bone turnover is high. There are significant health and safety implications for the racing industry.
  
  
  BACKGROUND
  Professional jockeys routinely sustain fractures from high impact falls. Jockeys maintain a low percentage body fat and a low body mass index (BMI) to achieve low weight targets in order to race. We evaluated dietary habits and bone metabolism in jockeys.
  
  
  METHODS
  Bone mineral density (BMD) was measured in 27 male jockeys of the 144 jockeys licensed in Ireland. Fourteen (52%) had BMD T score below -1.0, of whom 12 consented to clinical review, nutritional survey, endocrine studies, and bone turnover markers (BTM). BTM were compared to age- and sex-matched controls (n = 16).
  
  
  RESULTS
  BMI was 20.6 +/- 1.7 kg/m(2); previous fracture frequency was 3.2 +/- 2.0 per rider. All had normal endocrine axes. The jockeys' diet as determined by a 7-day dietary recall was deficient in energy, calcium, and vitamin D intake. Compared with the control group, the jockey group had evidence of increased bone turnover.
  
  
  CONCLUSIONS
  A substantial proportion of the professional jockeys in Ireland have low-normal BMD, low BMI, and high bone turnover that may result from weight and dietary restrictions. These factors seem to have a deleterious effect on their bone health and predispose the jockeys to a high fracture risk that should be remediated.
authors.affiliation: Adelaide and Meath Hospital, Dublin, Ireland. frank.waldron-lynch@yale.edu
authors.forename: F
authors.initials: F
authors.lastname: Waldron-Lynch
authors.forename: B F
authors.initials: BF
authors.lastname: Murray
authors.forename: J J
authors.initials: JJ
authors.lastname: Brady
authors.forename: M J
authors.initials: MJ
authors.lastname: McKenna
authors.forename: A
authors.initials: A
authors.lastname: McGoldrick
authors.forename: G
authors.initials: G
authors.lastname: Warrington
authors.forename: G
authors.initials: G
authors.lastname: O'Loughlin
authors.forename: J M
authors.initials: JM
authors.lastname: Barragry
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000503:physiopathology; D001842:Bone and Bones / Q000378:metabolism*; D016022:Case-Control Studies; D004032:Diet / Q000009:adverse effects; D005247:Feeding Behavior; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000209:etiology* / Q000503:physiopathology; D013177:Sports / Q000502:physiology*; D055815:Young Adult