Physical Activity, Menstrual History, and Bone Microarchitecture in Female Athletes with Multiple Bone Stress Injuries

Abstract

Bone stress injuries (BSI) occur in up to 20% of runners and military recruits and those with a history of BSI have a fivefold higher risk for a subsequent BSI. Yet, little is known about prior training, menstrual status, and bone structure in runners who experience multiple BSI.PurposeTo determine differences in health and physical activity history, bone density, microarchitecture, and strength among female athletes with a history of multiple BSI, athletes with ≤1 BSI, and nonathletes.MethodsWe enrolled 101 women (age, 18–32 yr) for this cross-sectional study: nonathlete controls (n = 17) and athletes with a history of ≥3 BSIs (n = 21) or ≤1 BSI (n = 63). We collected subjects’ health and training history and measured bone microarchitecture of the distal tibia via high-resolution peripheral quantitative computed tomography (HR-pQCT) and areal bone mineral density of the hip and spine by dual-energy X-ray absorptiometry.ResultsGroups did not differ according to age, body mass index, age at menarche, areal bone mineral density, or tibial bone microarchitecture. Women with multiple BSI had a higher prevalence of primary and secondary amenorrhea (P < 0.01) compared with other groups. Total hours of physical activity in middle school were similar across groups; however, women with multiple BSI performed more total hours of physical activity in high school (P = 0.05), more hours of uniaxial loading in both middle school and high school (P = 0.004, P = 0.02), and a smaller proportion of multiaxial loading activity compared with other groups.ConclusionsThese observations suggest that participation in sports with multiaxial loading and maintaining normal menstrual status during adolescence and young adulthood may reduce the risk of multiple bone stress injuries.

Impaired Bone Microarchitecture at Distal Radial and Tibial Reference Locations Is Not Related to Injury Site in Athletes With Bone Stress Injury

“… 18 , 26 However, considering that aBMD Z-scores were heterogeneous and some were even within the upper reference range, aBMD alone may provide only a limited explanation for the occurrence of BSI. 33 This finding was expected, as it is known that BSI can occur in the presence of high stress and strain without a reduced bone-loading capacity (ie, normal bone and remodeling). 16 Contrary to previous reports, no differences in the aBMD Z-score were revealed among anatomic sites, and no difference was observed when comparing bones with greater cortical versus trabecular composition.…”

“…39 Overall, the clinical relevance to differentiate among sites was highlighted by previous reports showing that bones of higher trabecular composition require a comparably longer time to heal 27 and that the risk for nonunion differs among the sites. 7 Few studies have elaborated on the osseous microstructural alterations in athletes with BSI, 1,33,35,36,46 albeit no study comprising biochemical, DXA, and HR-pQCT data in a comparable cohort size has been reported thus far. In our study cohort, cortical thickness and area at the distal radius and tibia as well as trabecular bone volume fraction at the distal radius were reduced compared with those in controls.…”

“…Few studies have elaborated on the osseous microstructural alterations in athletes with BSI, 1 , 33 , 35 , 36 , 46 albeit no study comprising biochemical, DXA, and HR-pQCT data in a comparable cohort size has been reported thus far. In our study cohort, cortical thickness and area at the distal radius and tibia as well as trabecular bone volume fraction at the distal radius were reduced compared with those in controls.…”

“…However, only a few studies have performed HR-pQCT examinations in patients with BSI. 1 , 33 , 35 , 36 , 46 Importantly, there have been no HR-pQCT studies investigating the association between alterations in bone microarchitecture and anatomic injury site. Therefore, the aim of this study was to assess bone microarchitecture by HR-pQCT in athletes with BSI and to compare findings between injury sites.…”

Do we need to change the guideline values for determining low bone mineral density in athletes?

“…Markers of LEA are associated with a 4.5 times greater rate of bone injuries in national/world-class female and male distance athletes ( 24 ). On the other hand, participation in sports with multiaxial loading combined with having a regular menstruation during adolescence and young adulthood may reduce the risk of multiple bone stress injuries ( 25 ).…”