Restrictive Eating and Prior Low-Energy Fractures Are Associated With History of Multiple Bone Stress Injuries

6Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA Bone stress injuries (BSIs) are common among athletes and have high rates of recurrence. However, risk factors for multiple or recurrent BSIs remain understudied. Thus, we aimed to explore whether energy availability, menstrual function, measures of bone health, and a modified Female Athlete Triad Cumulative Risk Assessment (CRA) tool are associated with a history of multiple BSIs. We enrolled 51 female runners (ages 18-36 years) with history of <= 1 BSI (controls; n= 31) or >= 3 BSIs (multiBSI; n= 20) in this cross-sectional study. We measured lumbar spine, total hip, and femoral neck areal bone mineral density by dual -energy X-ray absorptiometry, bone material strength index using impact microindentation, and volumetric bone mineral density, microarchitecture, and estimated strength by high-resolution peripheral quantitative computed tomography. Participants completed questionnaires regarding medical history, low-energy fracture history, and disordered eating attitudes. Compared with controls, multiBSI had greater incidence of prior low-energy fractures (55% vs. 16%, p= .005) and higher modified Triad CRA scores (2.90 +/- 2.05 vs. 1.84 +/- 1.59, p = .04). Those with multiBSI had higher Eating Disorder Examination Questionnaire (0.92 +/- 1.03 vs. 0.46 +/- 0.49, p= .04) scores and a greater percentage difference between lowest and highest body mass at their current height (15.5% +/- 6.5% vs. 11.5% +/- 4.9% p = .02). These preliminary findings indicate that women with a history of multiple BSIs suffered more prior low-energy fractures and have greater historical and current estimates of energy deficit compared with controls. Our results provide strong rationale for future studies to examine whether subclinical indicators of energy deficit contribute to risk for multiple BSIs in female runners.