Osteoporosis and osteopaenia in female athletes

Osteoporosis or osteopaenia in female athletes

• osteoporosis
  • defined as a bone mineral density more than 2.5 standard deviations below the average for young adults
  • associated with a reduction in bone mass with no alteration in the mineralisation of bone tissue
    • bone tissue responds well to mechanical stress, and thus exercise, alongside nutrition, is essential in the teenage years to attain peak bone mass
• women with low energy availability and low oestrogen concentrations, however, have increased risk of becoming osteoporotic
  • oestrogen protects the skeleton from bone resorption
  • deficiencies in calcium, vitamin D, and other bone trophic substances from inadequate nutritional intake also lead to increased bone resorption
  • long term risk of osteoporosis seems to be reduced by attaining a good peak bone mineral density in early life and by lifelong exposure to oestrogen
    • therefore long periods of amenorrhoea may increase the long term risk of osteoporosis
• ostoeopenia is much more common than osteoporosis in female athletes and associated with decalcification
  • osteopenia, a bone mineral density score between 1.0 and 2.5 SD for age, seems much more clinically relevant
  • there is evidence that only 10% of female distance runners had osteoporosis yet nearly 50% had osteopenia (2)

Reference:

• 1) Birch K. Female athlete triad. BMJ 2005;330(7485):244-6
• 2) Schtscherbyna A et al. Female athlete triad in elite swimmers of the city of Rio de Janeiro. Brazil Nutrition 2009;25(6): 634-639.