High prevalence of stress fractures and long-term amenorrhoea in high endurance female athletes: The misleading lack of correlation with bone mineral density.

Aim & Objectives: Females who engage in high levels of sports have a high prevalence of menstrual cycle disorders and bone stress injuries (BSI). In this study, we determined the prevalence of menstrual disorders and fractures in female athletes and their association with bone mineral density (BMD) parameters.

Material & Methods: Cross-Sectional Study. Forty-one female athletes from a public High-Performance Regional Centre; 24 high-endurance athletes (HEA) and 17 other athletes, were included. To form the control group, we invited medical students from a public University. Twenty-nine non-athletes (NA) were included. A health surveys and a dual-energy X-ray absorptiometry (DXA) were conducted for all participants.

Results: Among the participants (median age, 24 years; body mass index, 21 kg/m2), the percentage of long-term amenorrhoea was 42 % in HEA vs. 0 % in NHEA (OR 25.35; 95 % CI 1.37-470.50, p = 0.008) or 10 % in NA (OR 6.20; 95 % CI 1.46-26.24, p = 0.022), and the percentage of BSI was 29 % in HEA vs. 0 % in NHEA or NA. Both groups of female athletes (HEA and NHEA) showed higher Z-scores than those of NA in the femur; however, only NHEA had a significant increase in the BMD on lumbar spine than that of NA.

Conclusion: The prevalence of long-term amenorrhoea and/or BSI was significantly higher in the HEA than in the NHEA or NA females. In contrast, HEA, like NHEA, had higher BMD values in the femur than those of controls. It is unlikely that DXA parameters can be used to estimate cortical BSI risk in this population.