Athletes have higher bone mineral density (BMD)
relative to nonathletes. In amenorrheic athletes BMD may be
compromised by estrogen deficiency, but it is unknown whether
this is accompanied by structural differences. We compared
femoral neck bone geometry and density of a-/oligomenorrheic
athletes (AAs), eumenorrheic athletes (EAs), and eumenorrheic
controls (ECs). We recruited 156 women: (68 endurance athletes
and 88 controls). Femoral neck BMD, section modulus (Z),
and width were measured using dual-energy X-ray absorptiometry.
Menstrual function was assessed by questionnaire and
classified as EA(C10 periods/year) or AA(B9periods/year): 24
athletes were AA and 44 EA. Femoral neck BMD was significantly
higher in EA than AA (8 %, difference) and EC (11 %
difference): mean [SE] 1.118 [0.015], 1.023 [0.020] and 0.999
[0.014] g cm-2, respectively; p\0.001. Z was significantly
higher in EA than EC (11 % difference): EA 667 [19], AA 625
[21], and EC 592 [10] cm3; p\0.001. Femoral neck width did
not differ between groups. All differences persisted after
adjustment for height, age, and body mass. The higher femoral
neck Z and BMD in athletes, despite similar width, may indicate that exercise-related bone gains are endosteal rather than periosteal.
Athletes with amenorrhea had smaller increments in bone
mass rather than structural adaptation. The maintained femoral
neck width in controls may be an adaptive mechanism to conserve bone strength in bending despite inactivity-related bone decrement.
History
School
Sport, Exercise and Health Sciences
Published in
Calcified Tissue International
Volume
92
Issue
5
Pages
444 - 450
Citation
DUCKHAM, R.L. ... et al., 2013. Bone geometry according to menstrual function in female endurance athletes. Calcified Tissue International, 92(5), pp.444-450.