Skeletal effects of menstrual disturbances in athletes

Link Between the Female Athlete Triad and Gymnastics-Related Injury in Retired Collegiate Gymnasts

OBJECTIVES

To compare gymnastics-related injuries between former collegiate gymnasts who did and did not report components of the female athlete triad (Triad) during college, including disordered eating or menstrual irregularity. We hypothesized that athletes reporting these 2 triad symptoms would have higher rates of time loss injury and injuries requiring surgery.

DESIGN

Retrospective case-control.

SETTING

Online survey.

PATIENTS

Four hundred seventy former collegiate gymnasts.

INTERVENTIONS

Athletes completed online survey distributed through social media.

MAIN OUTCOME MEASURES

Participants were grouped based on self-reported menstrual irregularity and disordered eating during college. We compared time loss injuries, injuries resulting in surgery, and injury locations between the groups using χ2 analyses.

RESULTS

Seventy percent (n = 328) of participants in this study reported a time loss college injury without surgery, and 42% (n = 199) reported an injury during college that required surgical treatment. A significantly greater proportion of gymnasts with only disordered eating reported a time loss gymnastics injury (without surgery) compared with those who reported only menstrual irregularity during college (79% vs 64%; P =0 .03). A significantly greater proportion of the disordered eating-only group reported a spine injury compared with the menstrual irregularity-only group (P = 0.007) and the group who reported neither menstrual irregularity nor disordered eating (P = 0.006).

CONCLUSIONS

College gymnasts who experienced disordered eating were more likely to experience a nonsurgical time loss injury while in college, as well as spine injury compared with those with menstrual irregularity. Sports medicine providers should be aware of the association between injuries and individual components of Triad in gymnasts beyond bone stress injuries.

Energy deficiency, menstrual disorders, and low bone mineral density in female athletes: a systematic review

PURPOSE

Low energy availability (LEA) may lead to menstrual disorders and low bone mineral density, predisposing to the female athlete triad. The primary aim of the present review was to systematically investigate the impact of chronic strenuous exercise on the energy status of professional female athletes compared to sedentary, recreationally active controls as concerns their menstrual status and bone mineral density (BMD). A secondary aim was evaluation of the combined prevalence of the components of the female athlete triad in athletes as compared to non-athletes.

METHODS

A systematic review was conducted from 2007 to February 2018. The inclusion and exclusion criteria of the studies were established in advance of the literature search according to the clinical inquiry and the study design.

RESULTS

Four studies were included in this systematic review. The female athlete triad was more prevalent in professional athletes compared to non-athletes. The same results were obtained for both LEA and menstrual disorders. However, BMD and Z-scores showed high heterogeneity among the studies.

CONCLUSION

Both female athletes and non-athletes are prone to LEA and subsequent menstrual disorders and low BMD or osteoporosis. Future studies are needed to examine energy availability in elite female athletes as well as in non-athletes.

Maternal investment, maturational rate of the offspring and mechanical competence of the adult female skeleton

LAY SUMMARY

Girls with a slower life history trajectory build a larger body with larger and mechanically stronger bones. Thus, variation in the emergence of slower versus faster life history trajectories during development can have consequences for bone mechanical competence, and hence fracture risk in adulthood.

BACKGROUND AND OBJECTIVES

Variation in life history trajectory, specifically relative investment in growth versus reproduction, has been associated with chronic disease risk among women, but whether this scenario extends to skeletal health and fracture risk is unknown. This study investigates the association of life history traits (proxies for maternal investment and maturational rate) with female bone outcomes in adulthood.

METHODOLOGY

Body size variables, regional muscle and fat areas, and cross-sectional bone size and strength outcomes were obtained from 107 pre-menopausal women encompassing a wide range of physical activity levels. Developmental parameters (birth weight, age at menarche) were obtained from questionnaires.

RESULTS

High birth weight was significantly associated with a proportionately larger body and larger, mechanically stronger bones, independently of physical activity level. It was also positively but non-significantly associated with age at menarche. Later menarche was significantly associated with larger and mechanically stronger bones and substantially less absolute and relative regional subcutaneous fat. Age at menarche exhibited stronger relationships with adult adiposity than did physical activity.

CONCLUSIONS AND IMPLICATIONS

Both larger birth weight and later menarche contribute to a slower life history trajectory, which is associated with greater body size, leanness and bone mechanical competence in early adulthood. In contrast, earlier sexual maturity prioritized energy allocation in adiposity over body size and skeletal strength. Thus, the level of maternal investment and the woman's own life history trajectory shape investment in skeletal properties, with implications for fracture risk later in life.

Athletic activity and hormone concentrations in high school female athletes

CONTEXT

Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical.

OBJECTIVE

To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean-body-mass to fat-body-mass ratio with accompanying hormonal changes.

DESIGN

Cohort study.

SETTINGS

Laboratory and participants' homes.

PATIENTS OR OTHER PARTICIPANTS

A total of 106 adolescent girls, ages 14-18 years, who had experienced at least 3 menstrual cycles in their lifetime.

MAIN OUTCOME MEASURE(S)

Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period.

RESULTS

Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant.

CONCLUSIONS

A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the participants achieved high levels of physical activity. A significant number (17%) of girls in both activity groups were amenorrheic during the 3-month study period.

Bone geometry according to menstrual function in female endurance athletes

Athletes have higher bone mineral density (BMD) relative to nonathletes. In amenorrheic athletes BMD may be compromised by estrogen deficiency, but it is unknown whether this is accompanied by structural differences. We compared femoral neck bone geometry and density of a-/oligomenorrheic athletes (AAs), eumenorrheic athletes (EAs), and eumenorrheic controls (ECs). We recruited 156 women: (68 endurance athletes and 88 controls). Femoral neck BMD, section modulus (Z), and width were measured using dual-energy X-ray absorptiometry. Menstrual function was assessed by questionnaire and classified as EA (≥10 periods/year) or AA (≤9 periods/year): 24 athletes were AA and 44 EA. Femoral neck BMD was significantly higher in EA than AA (8 %, difference) and EC (11 % difference): mean [SE] 1.118 [0.015], 1.023 [0.020] and 0.999 [0.014] g cm(-2), respectively; p < 0.001. Z was significantly higher in EA than EC (11 % difference): EA 667 [19], AA 625 [21], and EC 592 [10] cm(3); p < 0.001. Femoral neck width did not differ between groups. All differences persisted after adjustment for height, age, and body mass. The higher femoral neck Z and BMD in athletes, despite similar width, may indicate that exercise-related bone gains are endosteal rather than periosteal. Athletes with amenorrhea had smaller increments in bone mass rather than structural adaptation. The maintained femoral neck width in controls may be an adaptive mechanism to conserve bone strength in bending despite inactivity-related bone decrement.

The female athlete triad

Context:

The female athlete triad (the triad) is an interrelationship of menstrual dysfunction, low energy availability (with or without an eating disorder), and decreased bone mineral density; it is relatively common among young women participating in sports. Diagnosis and treatment of this potentially serious condition is complicated and often requires an interdisciplinary team.

Evidence Acquisition:

Articles from 1981 to present found on PubMed were selected for review of major components of the female athlete triad as well as strategies for diagnosis and treatment of the conditions.

Results:

The main goal in treatment of young female athletes with the triad is a natural return of menses as well as enhancement of bone mineral density. While no specific drug intervention has been shown to consistently improve bone mineral density in this patient population, maximizing energy availability and optimizing vitamin D and calcium intake are recommended.

Conclusions:

Treatment requires a multidisciplinary approach involving health care professionals as well as coaches and family members. Prevention of this condition is important to minimize complications of the female athlete triad.

Diagnosis of medial knee pain: atypical stress fracture about the knee joint

STUDY DESIGN

Resident's case problem.

BACKGROUND

A 19-year-old female, currently enrolled in a military training program, sought medical care for a twisting injury to her right knee. The patient reported her symptoms as similar to an injury she incurred 1 year previously while enrolled in the same military program. The patient's past medical history included a nondepressed fracture of the medial tibial plateau and complete tear of the deep fibers of the medial collateral ligament.

DIAGNOSIS

Physical exam revealed nonlocalized anterior and medial knee pain without evidence of internal derangement. Initial knee and tibia radiographs were unremarkable. Referral for orthopedic physician evaluation resulted in concurrence with the therapist's diagnosis and plan of care, and the patient was allowed to continue with limited physical training demands. Despite periods of rest, the patient's symptoms progressively worsened upon attempts to resume running. The examining therapist referred the patient for magnetic resonance imaging (MRI) due to the patient's worsening symptoms, normal radiographs, and concern for a proximal tibia stress fracture. MRI revealed a severe proximal tibial metaphysis stress fracture.

DISCUSSION

Stress fractures are commonly encountered injuries in individuals subjected to increased physical training demands. Early evaluation may not yield well-localized findings and may mimic other conditions. Nonmusculoskeletal conditions should be considered in the management of patients with stress fractures. This resident's case problem illustrates the importance of serial physical examinations and collaboration with other healthcare practitioners in the comprehensive assessment and management of a patient with a severe stress fracture.

Hyperandrogenicity is an alternative mechanism underlying oligomenorrhea or amenorrhea in female athletes and may improve physical performance

OBJECTIVE

To evaluate endocrine mechanisms underlying oligomenorrhea or amenorrhea in female athletes.

DESIGN

Cross-sectional study.

SETTING

Women's health clinical research unit at a university hospital.

PATIENT(S)

Age- and BMI-matched groups of athletes active in endurance sports with and without menstrual disturbances and regularly cycling sedentary controls.

INTERVENTION(S)

Groups were compared with respect to endocrine status, body composition, and physical performance.

MAIN OUTCOME MEASURE(S)

Identification of a subgroup of oligomenorrheic or amenorrheic athletes with increased androgen levels and anabolic body composition.

RESULT(S)

A subgroup of 8 of 25 athletes with menstrual disturbances had significantly higher serum levels of free and total testosterone, androstenedione, LH-FSH ratio, and lower SHBG levels than did all other groups. Other oligomenorrheic or amenorrheic athletes had normal values comparable to those in regularly menstruating athletes and controls. The hyperandrogenic subgroup showed a more anabolic body composition, with higher total bone mineral density and upper-lower fat mass ratio than did oligomenorrheic or amenorrheic athletes with normal androgen levels. The hyperandrogenic subgroup had the highest VO2 max and the highest performance values in general.

CONCLUSION(S)

Menstrual disturbances in female athletes are often explained as a consequence of hypothalamic inhibition and caloric deficiency. We suggest that essential hyperandrogenism is an alternative mechanism underlying oligomenorrhea or amenorrhea in some female athletes and may imply an advantage for physical performance.

Gender differences in acute mountain bike racing injuries

OBJECTIVE

To evaluate injury rates and patterns in off-road bicycle racing, and to compare the findings in male and female cyclists.

SETTING

The study was conducted from 1994-2001 at a large off-road bicycling competition held for 4 days each summer at Mammoth Mountain, California.

DESIGN

Injured cyclists were evaluated at the first aid station or at the local hospital. Registration data were used to estimate the number of male and female competitors in each race.

PARTICIPANTS

Cyclists who sustained an injury during a race and were unable to finish the race due to the injury were included in the study. 22 female subjects and 71 male subjects met the inclusion criteria during the 8-year study period. There were a total of 20,769 race participants during the study period.

MAIN OUTCOME MEASURES

Injuries were categorized, and injury rates were calculated.

RESULTS

The overall injury rate during the study period was 0.77% (22/2,869) for women versus 0.40% (71/17,900) for men (p = 0.01). Fractures were sustained by 45.5% (10/22) of female subjects versus 21.1% (15/71) of male subjects (p = 0.03). Odds ratios indicate that overall, women were 1.94 times more likely than men to sustain an injury and 4.17 times more likely to sustain a fracture.

CONCLUSIONS

These data suggest that although participation in this sport is higher among men, the risk of injury is greater for women.

Hypothalamic amenorrhea. The effects of environmental stresses on the reproductive system: a central effect of the central nervous system

Although the treatment of anovulation has become significantly more specialized and complex in the centuries since Hippocrates, a complete understanding of the causes and mechanisms of hypothalamic amenorrhea has not been achieved. Even the best research on hypothalamic amenorrhea is plagued by the lack of longitudinal studies, the use of different exercise models, the difficulty of controlling for caloric intake, and the fact that genetics may have a role in the disorder. Continuing research on metabolic rate, leptin, and other factors will ultimately answer many of the outstanding questions and will help to create better tools for treating this disorder.

Dose-response of physical activity and low back pain, osteoarthritis, and osteoporosis

PURPOSE

The purpose of this study was to examine the evidence for causal relationships between physical activity (PA) and low back pain (LBP), osteoarthritis (OA), and osteoporosis (OP), and for dose-response relations involved.

METHODS

Computer database searches and personal retrieval systems were used to locate relevant literature.

RESULTS

PA can be effective in preventing LBP (Category A) but prolonged, heavy loading can lead to LBP (Category C). Specific exercises have not been found effective in treatment of acute LBP (Category A), but PA can be effective in chronic LBP (Category B), especially for diminishing the effects of deconditioning. No evidence indicates that PA directly prevents OA. Large amounts of intensive PA involving high impacts or torsional loadings or causing injuries increases risk of OA (Category C). Light or moderate PA does not increase the risk of OA (Category C). PA can be effective in the treatment and rehabilitation of OA (Category B). High-intensity loading is osteogenic and possibly useful in prevention of OP (Category A) at the loaded site, but low to moderate loading is not osteogenic (Category D). Static efforts and slow movements are ineffective or less effective than fast application of force (Category B). The types of PA to attain the effects mentioned above are known except in the case of prevention of LBP, but dose-response relationships are poorly known; at best, semiquantitatively on the basis of just a few studies.

CONCLUSION

Given the shown primary and/or secondary preventative effectiveness of PA regarding LBP, OA, and OP, research to elucidate the inadequately known dose-response relations should be given high priority.

Is there a role for exercise in the prevention of osteoporotic fractures?

OBJECTIVES

To examine whether there is a role for exercise in improving bone mineral density (BMD), particularly in postmenopausal women. The effects of different types of exercise are examined together with their effects at selected skeletal sites. The role of activity in reducing falls and hip fractures will also be considered as well as the potentially negative effects of excessive exercise.

METHODS

A literature search over the past 20 years was conducted and landmark papers selected.

RESULTS

Certain types of exercise have been found to exert moderate benefits on BMD of the wrist, spine, and hip. Most studies do not detect a difference between the effects of endurance activities and strength training for BMD of the spine. It has been more difficult to isolate the optimal type of activity for effecting an osteogenic response at the hip, but recent evidence suggests that high impact work such as stepping and jumping may be effective at this site. The combination of hormone replacement therapy and exercise would appear to be more effective than either intervention on its own. Certain types of exercises have additional benefits, such as muscle strengthening, which could reduce the incidence of falls. Excessive exercise can lead to menstrual disturbances in female athletes and this in turn can cause bone loss, particularly from the spine.

CONCLUSIONS

Exercise across the life span should be encouraged in order to maximise peak bone mass, reduce age related bone loss, and maintain muscle strength and balance. Although the effects of exercise on BMD later in life are small, epidemiological evidence suggests that being active can nearly halve the incidence of hip fractures in the older population. This effect is most probably multifactorial through the positive effects on bone, muscle strength, balance, and joint flexibility. Younger women should be aware of the dangers to the skeleton of menstrual disorders.

Risk factors for stress fractures

Preventing stress fractures requires knowledge of the risk factors that predispose to this injury. The aetiology of stress fractures is multifactorial, but methodological limitations and expediency often lead to research study designs that evaluate individual risk factors. Intrinsic risk factors include mechanical factors such as bone density, skeletal alignment and body size and composition, physiological factors such as bone turnover rate, flexibility, and muscular strength and endurance, as well as hormonal and nutritional factors. Extrinsic risk factors include mechanical factors such as surface, footwear and external loading as well as physical training parameters. Psychological traits may also play a role in increasing stress fracture risk. Equally important to these types of analyses of individual risk factors is the integration of information to produce a composite picture of risk. The purpose of this paper is to critically appraise the existing literature by evaluating study design and quality, in order to provide a current synopsis of the known scientific information related to stress fracture risk factors. The literature is not fully complete with well conducted studies on this topic, but a great deal of information has accumulated over the past 20 years. Although stress fractures result from repeated loading, the exact contribution of training factors (volume, intensity, surface) has not been clearly established. From what we do know, menstrual disturbances, caloric restriction, lower bone density, muscle weakness and leg length differences are risk factors for stress fracture. Other time-honoured risk factors such as lower extremity alignment have not been shown to be causative even though anecdotal evidence indicates they are likely to play an important role in stress fracture pathogenesis.

Self-reported ballet classes undertaken at age 10-12 years and hip bone mineral density in later life

The major effect of weightbearing exercise on adult bone mass may be exerted during childhood. We examined the relationship between reported hours of ballet classes per week undertaken as a child and adult bone mineral density (BMD) at the hip, spine, and forearm. We performed a retrospective cohort study in 99 female retired dancers (mean age 51 years, SD 14 years) and 99 normal controls, derived from a twin study, matched hierarchically for age, height, weight and menopausal status. Starting age of ballet was recalled and weekly hours of ballet as a child was self-reported on two occasions. BMD was measured using dualenergy X-ray absorptiometry and reported as a Z-score. Self-reported hours of ballet class undertaken per week at each age between 10 and 12 years was positively associated with a difference in BMD between dancers and controls at both the femoral neck site (beta = 0.73, p = 0.001) and the total hip site (beta = 0.55, p < 0.01). These associations were unaffected by adjustment for covariates including measures of adult activity (current physical activity, years of fulltime ballet), measures of menstrual disturbance (age of menarche, history of irregular menses), dietary history (calcium intake as a child, adolescent or adult) or lifestyle factors (lifetime smoking, lifetime alcohol). Although starting age of ballet was negatively associated with weight-adjusted within-pair hip BMD difference, it was no longer associated after adjustment for weekly hours of ballet. There was no relationship between hours of ballet undertaken as a child and differences in BMD at the lumbar spine or upper limb, at any age. Our data suggest that classical ballet classes undertaken between the ages of 10 and 12 years are independently and positively associated with a difference in hip BMD between dancers and controls. The findings are consistent with the hypothesis that this age range identifies a stage of development when the proximal femur is particularly responsive to weightbearing exercise.