Correlates of Stress Fractures Among Preadolescent and Adolescent Girls

Abstract

ABSTRACT. Objective. Although stress fractures are a source of significant morbidity in active populations, particularly among young female athletes, the causes of stress fractures have not been explored among females <17 years of age or in the general population. The purpose of this study was to examine correlates of stress fractures in a large, population-based, national, cohort study of preadolescent and adolescent girls.Methods. A cross-sectional analysis of data from 5461 girls, 11 to 17 years of age, in the Growing Up Today Study, an ongoing longitudinal study of the children of registered female nurses participating in Nurses' Health Study II, was performed. Mothers self-reported information regarding their children's histories of stress fractures on their 1998 annual questionnaire. Growing Up Today Study participants self-reported their weight and height, menarcheal status, physical activity, dietary intake, and disordered eating habits on annual surveys.Results. In 1998, the mean age of the participants was 13.9 years. Approximately 2.7% of the girls had a history of stress fracture, 3% engaged in disordered eating (using fasting, diet pills, laxatives, or vomiting to control weight), and 16% participated in >16 hours per week of moderate to vigorous activity. Age at menarche, z score of BMI in 1998, calcium intake, vitamin D intake, and daily dairy intake were all unrelated to stress fractures after controlling for age. Independent of age and BMI, girls who participated in >16 hours per week of activity in 1998 had 1.88 greater odds of a history of stress fracture than did girls who participated in <4 hours per week (95% confidence interval [CI]: 1.18 -3.30). Girls who participated in >16 hours per week of activity were also more likely than their peers to engage in disordered eating (4.6% vs 2.8%); however, disordered eating did not have an independent association with stress fractures (odds ratio Conclusions. These findings suggest that, although activity can be beneficial for bone health, there is a threshold over which the risk of stress fracture increases significantly among adolescent girls. High-impact activities, particularly running, cheerleading, and gymnastics, appear to be higher risk than other activities. Prospective studies are needed to explore the directionality of these relationships, as well as the role of menstrual history. In the meantime, clinicians should remain vigilant in identifying and treating disordered eating and menstrual irregularities among their highly active, young, female patients. Pediatrics 2005; 115:e399-e406. URL: www.pediatrics.org/cgi[

Relationships Among Injury and Disordered Eating, Menstrual Dysfunction, and Low Bone Mineral Density in High School Athletes: A Prospective Study

“…Although our findings are in accordance with a crosssectional study of stress fractures among adolescent females, 21 they should be interpreted cautiously. The athletes reporting oligomenorrhea/amenorrhea during the past year had an older menarcheal age than athletes reporting normal menses.…”

“…Although the literature in collegiate and competitive female athletes suggests a relationship among 1 or more triad components and stress fracture or other musculoskeletal injury, whether relationships exist among 1 or more triad components as risk factors for musculoskeletal injury in adolescent athletes is presently unclear. In a study of 5461 adolescent girls, Loud et al 21 did not show an association between stress fracture and disordered eating or menarcheal age. However, their findings were limited in that the cross-sectional design used did not allow them to determine if these risk factors preceded the stress fractures, and the lack of association between disordered eating and stress fracture may have been due to low statistical power.…”

Family History Predicts Stress Fracture in Active Female Adolescents

“…1,2 We have recently reported a 2.7% estimated lifetime prevalence of this injury in female adolescents, 3 which compares favorably with estimates ranging from 1.0% to 2.6% among general collegiate athletes. 4,5 Although these overall rates seem low, certain subgroups, such as college freshmen 6 and other young adult women participating in track and field [7][8][9][10][11] may have rates of stress fracture between 6.9% 6 and 21.1%.…”

“…Our previous work demonstrated that the quantity of physical activity is significantly associated with history of self-reported stress fracture diagnosis, with each hour/week of high-impact exercise increasing the odds of stress fracture by 5%, but we could not identify a threshold amount of physical activity above which the risk of stress fracture would be deemed unsafe. 3 Therefore, to fill the gaps in knowledge about the risk factors for stress fracture in active female adolescents, we designed a case-control study to estimate the associations between a diagnosis of stress fracture with amount of physical activity and MI. Important covariates also included dietary intake of calcium and vitamin D, BMI, and family history of skeletal impairment.…”

“…19,20 Studies have inconsistently shown MI to be a risk factor for stress fracture in active adult women, [21][22][23][24][25][26] but information on menstrual history was not available from the large epidemiologic cohort that we analyzed previously. 3 Inadequate skeletal load-bearing capacity, as caused by the factors just mentioned, is not a sufficient condition for stress fracture. By definition, repetitive loading of a bone, as caused by physical activity, is necessary as well.…”