Interval Changes in Bone Mineral Density in Exercising Young Women with or without Menstrual Dysfunction—an 18-month Longitudinal Study

Abstract

Objectives: To evaluate the bone mineral density changes of the axial and appendicular skeleton in a group of collegiate dance students undergoing intensive physical training over an 18-month interval and to assess any differences between those with or without menstrual dysfunction during their training.
Methods: Full-time collegiate dance students were recruited from a tertiary performing arts institute. All subjects had basic anthropometric assessment, dual energy X-ray absorptiometry, and quantitative peripheral computed tomographic scans to determine bone mineral density. The measurements were then repeated around 18 months after the initial assessment. Subjects who had suffered from oligomenorrhoea and amenorrhoea during the 18-month training were compared to those who had remained eumenorrhoeic. All subjects were also compared to a group of non-exercising eumenorrhoeic controls of comparable age.
Results: There was no significant difference in the initial bone mineral density measurements of the axial and appendicular skeleton between the two groups. The exercising group showed larger interval increments over the 18-month interval in lumbar spine bone mineral density as well as hip bone mineral density values as compared to non-exercising controls (n=19), which had minimal increments (p<0.001). Within the exercising group, those who developed oligo/amenorrhoea (n=10) showed marginally lower core trabecular bone mineral density increments as compared to those that remained eumenorrhoeic (n=26).
Conclusion: Young women undergoing regular intensive weight-bearing exercises as in the collegiate dancers here studied have higher bone mineral density accrual as compared to non-exercising females of the same age-group. Oligo/amenorrhoea during training could have a small negative impact on such bone accrual.