Injuries outside of horseracing: is it time to focus on injury prevention of jockeys outside of races?

Objectives: Falls and injuries are frequent in professional horseracing. However, professional jockeys spend a large part of their week in horse-related activities outside of racing such as schooling, exercise riding, and yard-related activities. The injury risk related to these activities remains largely unknown internationally. This study aimed to identify the injury prevalence and injury profile of flat and jump jockeys during non-racing activities. Methods: In total 45.6% and 38.5% of all licensed Irish professional flat and jump jockeys completed a cross-sectional self-recall questionnaire examining injuries that occurred outside of racing during 2018. Injury proportion, repeat incidence proportion, and descriptive statistics were calculated. Results: Fifteen percent of professional jockeys sustained an injury outside of a race, half of those injured receiving at least another injury in 2018 and 66.52 injuries per 1,000 falls were noted. Injuries frequently occurred to the upper limb (36.67%), with fractures common (32.00%). Most injuries occurred due to a fall (60.00%) and 77.27% occurred in the gallops. Half of injuries resulted in the jockey missing racing, with 31.00 ± 47.18 (4-180) days lost on average. Twenty-three percent of jockeys attended hospital and 16.67% required surgery due to injury. Interestingly, just under a third did not report their injury to anyone. Conclusion: Injuries to professional jockeys, whilst not as frequent outside of racing, tend to be serious and can affect jockeys financially and impact their availability to ride. Prioritizing injury prevention strategies to maximize availability of jockeys to race is important. Education on the importance of reporting all injuries regardless of where they occur is important to ensure their management and rehabilitation.

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

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.

Nutritional, lifestyle, and weight control practices of professional jockeys.

In this study, we describe diet and lifestyle practices of professional jockeys. Participants completed a 59-item nutrition, lifestyle, and health questionnaire (n = 21) and a 7-day estimated food diary (n = 18). Acute weight loss strategies included the use of saunas (86%), exercising to induce sweating (81%), and restricted energy intake (71%). Of the smokers (38%), 56% used smoking to control weight. Most (86%) jockeys reported attaining a 2-kg weight loss for racing (if required) 24-48 h before or on the designated race-day. Mean daily energy intake (1803 ± 564 kcal) was low and appeared to provide an insufficient availability of energy for sustainment of usual daily and metabolic processes. Carbohydrate intake (3.7 ± 1.3 g · kg⁻¹) was below recommendations for athletes. A substantial proportion of jockeys failed to meet the estimated average requirement and lower threshold intake for a number of micronutrients. Jockeys consumed well below (0-2) the recommended five daily servings of fruit and vegetables set by the World Health Organization. Pressures of the jockey lifestyle and rigid weight limits appear to encourage unhealthy weight management practices in this group and may risk long term-health.

Microbial mannan inhibits bacterial killing by macrophages: a possible pathogenic mechanism for Crohn's disease.

BACKGROUND & AIMS: Crohn's disease (CD) is mimicked by inherited phagocyte disorders and is associated with circulating antibodies against yeast mannan (anti-Saccharomyces cerevisiae antibody; ASCA). We speculated that mannans might impair phagocyte function. METHODS: S cerevisiae mannan was assessed for its effects on human peripheral blood neutrophils, adherent monocytes, and monocyte-derived macrophages (MDM). RESULTS: Mannan caused dose-related increased survival of CD Escherichia coli HM605 within adherent monocytes from 24% +/- 10.5% (control) to 114% +/- 22.7% with mannan 1 mg/mL at 2 hours (mean +/- SEM, n = 9; P = .0002). Electron microscopy showed E coli HM605 surviving and probably replicating within macrophage vesicles. Mannan (1 mg/mL) inhibited the respiratory burst in neutrophils and monocytes (both P = .002) and bacterial killing within MDM (P < .001). E coli survival was increased within macrophages from TLR4(-/-) (126% +/- 3.5% survival at 2 hours) and MyD88(-/-) (134.8% +/- 6.5%) mice compared with wild-type mice (both P < .0001). Mannan had no additional effect, showing that TLR4 and MyD88 are involved in bacterial killing by macrophages and its inhibition by mannan. Putative CD-associated micro-organisms were screened for the ASCA mannan epitope by Galanthus nivalis lectin (GNA) blotting. ASCA epitope was expressed by Candida albicans and Mycobacterium paratuberculosis but not by Mycobacterium tuberculosis or E coli. Supernatants from M paratuberculosis culture inhibited killing of E coli HM605 by adherent human monocytes and murine macrophages. The inhibitory activity was removed by GNA-affinity chromatography. CONCLUSIONS: Suppression of mucosal phagocyte function by microbial mannans, possibly of Mycobacterial origin, may contribute to CD pathogenesis.