Low Bone Mineral Density: Not Just a Female Athlete Concern
Tracey Romero • Tue, January 16th, 2018
The association between bone stress injuries and low bone mineral density in female athletes has been a hot topic in sports medicine for a few decades now with the coining of the term Female Athlete Triad, a combination of eating disorders (or low energy availability), amenorrhea/oligomenorrhea and decreased bone mineral density (osteoporosis and osteopenia) in female athletes, but it is only more recently that the interplay of low energy availability, hormone levels and low bone mineral density has been explored in male athletes.
Adam S. Tenforde, M.D, assistant professor of Physical Medicine and Rehabilitation at Harvard Medical School in Boston, Massachusetts told OTW, “Low energy availability is thought to be more common in female athletes than male athletes; true prevalence and understanding sex-specific differences are areas of important future research.
“The terminology of Female Athlete Triad has been around for greater than two decades, and this terminology may have contributed to male athletes and sports medicine professionals to not think about how nutrition can affect parallel processes of altered hormonal function and bone density in men.”
He added, however, “Since the IOC [International Olympic Committee] position statement introducing RED-S [Relative Energy Deficiency in Sports], a term that helps to unify that athletes of both sexes with poor nutrition can experience consequences of impaired health and performance, it’s been positive to see more recognition that both sexes require optimized nutrition for health and injury prevention.”
Tenforde is the corresponding author on a recent study, “Low Bone Mineral Density in Male Athletes Is Associated with Bone Stress Injuries at Anatomic Sites with Greater Trabecular Composition,” published in the January 2018 issue of the American Journal of Sports Medicine, which explores further the connection between low bone mineral density and bone stress injuries (BSIs) in male athletes.
In this study, Tenforde and his colleagues reviewed the charts of 28 male athletes between the ages of 14 and 36 with a history of more than one lower-extremity bone stress injury (BSI). Bone mineral density scores (BMD Z-score) were determined for each of them and prior BSIs were classified by the anatomic site of the injury into two groups: trabecular-rich locations including the pelvis, femoral neck and calcaneus or cortical—rich locations including the tibia, fibula, femur, metatarsal and tarsal navicular.
According to the results, 12 (43%) of the 28 athletes had low bone mineral density and those athletes with a history of trabecular-rich had a 4.6-fold increased risk for low bone mineral density as compared to those athletes who only experienced cortical-rich BSIs (9 of 11 vs. 3 of 17; p = .002). In addition, runners had a 6.1-fold increased risk for low bone mineral density compared to nonrunners (11 of 18 vs 1 of 10; p = .016).
Overall Tenforde and his colleagues found that male athletes who are runners and/or have a history of trabecular-rich BSIs have an increased risk for low bone mineral density.
He said, “In female athletes, it was previously reported by Marx in 2001 that trabecular-rich sites of bone stress injury were associated with higher rate of low bone density compared to athletes with injuries at cortical-rich sites. Our study provides evidence that males appear to have similar association of trabecular-rich sites of bone injury to low bone density. It has been hypothesized that the trabecular bone has structure with greater surface area that is more sensitive to altered sex hormones including estradiol. We don't know the mechanism in males; however, it's possible males have a similar process of reduced sex hormones contributing to increased risk for bone stress injuries and lower bone density in trabecular-rich bone.”