Adolescence: Critical years for bone health
Poor bone health is one of the many negative outcome of Relative Energy Deficiency in Sport (RED-S). RED-S is caused by low energy availability (LEA), in which nutritional intake is insufficient to cover the energy demands of exercise expenditure and bodily processes. RED-S results in adverse effects on a variety of body systems: menstrual function, endocrine/hormones system musculoskeletal, gastrointestinal, cardiovascular system, immune function and growth and development
Bone strength is mostly build during the ‘bone accrual years” which are from approximately age 11 until early 20’s. If bone strength (compositions and architecture) is not optimized during this time period, the deficits are largely irreversible.
RED-S related late menarche or menstrual dysfunction during the teen years is essential to address and manage. Early identification can limit the impact of the LEA on bone health.
Unfortunately, all too often, menstrual dysfunction is accepted as a normal consequence of athletics and is ignored. Often times, these athletes first present with recurrent bony stress injuries, which are the result of impacted bone health.
Female athletes with amenorrhea have a high risk for low BMD or osteoporosis. Studies have shown that female athletes with lower bone density of the lumbar spine have between 3 and 5 times higher risk of stress bone injuries, compared with athletes with normal BMD.
The following article, by Nose-Ogura et al. 2020, clearly illustrates the impact of menstrual dysfunction during the adolescent years: This group of researchers took 210 elite athletes from a variety of sports and retrospectively divided them into 3 groups:
Group A: >1 year of amenorrhea in teens and 20’s
Group B: regular menstrual function in teens, >1yr of amenorrhea in 20’s
Group C: Regular menstrual function in teens and 20’s
Findings: “Our study showed that amenorrhea for greater than 1 year during teenage years and low BMI at present are independent correlation factors for low BMD in female athletes. We also found that an athlete with amenorrhea for greater than 1 year during the teenage years is 23 times more likely to develop low BMD in univariable logistic regression analysis. In the multivariable logistic regression analysis, secondary amenorrhea in their teens and BMI at present were independent correlation factors for low BMD. Moreover, when we looked at the actual BMD value, BMD in athletes who had amenorrhea in their teens was lower than that in athletes with regular menstruation in their teens.”
Conclusions: Secondary amenorrhea for at least 1 year during teenage years in female athletes and BMI at present was strongly associated with low BMD in their 20s. Early screening for secondary amenorrhea and low BMI due to low energy availability could prevent low BMD and thus injuries, for example, stress fractures, which consequently influences women health over their lifetime.
In summary, late first menstruation and menstrual dysfunction needs to be addressed and managed in a timely way in order to limit impact on lifetime bone health. Studies show that male and female athletes from long distance running and cycling are frequently impacted. More recent evidence indicates that repetitive bone loading is not protective whereas multidirectional movement patterns tend to positively impact bone architecture. These concepts lead us to look at various bone loading programs specifically designed to optimize bone strength and architecture.
Nose-Ogura, Sayaka MD, PhD*,†,‡; Yoshino, Osamu MD, PhD†; Dohi, Michiko MD, PhD*; Kigawa, Mika PhD§; Harada, Miyuki MD, PhD‡; Kawahara, Takashi MD*; Osuga, Yutaka MD, PhD‡; Saito, Shigeru MD, PhD† Low Bone Mineral Density in Elite Female Athletes With a History of Secondary Amenorrhea in Their Teens, Clinical Journal of Sport Medicine: May 2020 - Volume 30 - Issue 3 - p 245-250
Gibbs JC, Nattiv A, Barrack MT, et al. Low bone density risk is higher in exercising women with multiple triad risk factors. Med Sci Sports Exerc. 2014;46:167–176.