La pratique du cyclisme de haut niveau impacte-t-elle la masse osseuse ?

Abstract

Background : Elite cyclists may be at risk for osteopenia. Many factors can lead to bone loss in cycling, including low energy availability, low grade of inflammation, and a weak mechanical osteogenic stimulus. Thus we wanted to assess bone health in one elite team of professional cyclists, and to identify correlations between BMD and potential risks factors.Methods : Thirty-three adult male cyclists were recruited from one international team. Total body, hip femur and lumbar spine BMD had been measured by DXA and was compared to standard values for a healthy population of same age and sex. Training characteristics, morphometrics, body lean mass, fat mass, history, medication and results of recent blood and stool analysis were collected and compared between the cyclists having low BMD and those with unaltered BMD. Univariate and multivariate correlation analyses were carried out to identify predictive factors for low BMD.Results : Twenty-one (64%) out of 33 cyclists presented a Z score < -1 at one site, and five of them (15%) had densitometric osteoporosis. Lumbar spine was involved every time ‘Z score = -b 1,23 +/- 0,94). Age, history, and training characteristics were significantly and negatively linked to BMD. After multiple regression, no variable had an independent correlation with BMD. No correlation was found with biomarkers or with training characteristics.Conclusion : Our study shows a worrying proposition of low bone mass in our population of young male and otherwise healthy cyclists. Low energy availability, as the missing point of our study, might be the main causal factor. Great attention should be paid in bone status in elite cyclists of any age.