The effect of oral contraceptives on bone mass and stress fractures in female runners

PURPOSE

To determine the effect of oral contraceptives (OC) on bone mass and stress fracture incidence in young female distance runners.

METHODS

One hundred fifty competitive female runners ages 18-26 yr were randomly assigned to OC (30 microg of ethinyl estradiol and 0.3 mg of norgestrel) or control (no intervention) for 2 yr. Bone mineral density (BMD) and content (BMC) were measured yearly by dual x-ray absorptiometry. Stress fractures were confirmed by x-ray, magnetic resonance imaging, or bone scan.

RESULTS

Randomization to OC was unrelated to changes in BMD or BMC in oligo/amenorrheic (N=50) or eumenorrheic runners (N=100). However, treatment-received analyses (which considered actual OC use) showed that oligo/amenorrheic runners who used OC gained about 1% per year in spine BMD (P<0.005) and whole-body BMC (P<0.005), amounts similar to those for runners who regained periods spontaneously and significantly greater than those for runners who remained oligo/amenorrheic (P<0.05). Dietary calcium intake and weight gain independently predicted bone mass gains in oligo/amenorrheic runners. Randomization to OC was not significantly related to stress fracture incidence, but the direction of the effect was protective in both menstrual groups (hazard ratio [95% CI]: 0.57 [0.18, 1.83]), and the effect became stronger in treatment-received analyses. The trial's statistical power was reduced by higher-than-anticipated noncompliance.

CONCLUSION

OC may reduce the risk for stress fractures in female runners, but our data are inconclusive. Oligo/amenorrheic athletes with low bone mass should be advised to increase dietary calcium and take steps to resume normal menses, including weight gain; they may benefit from OC, but the evidence is inconclusive.

Risk factors for stress fracture among young female cross-country runners

PURPOSE

To identify risk factors for stress fracture among young female distance runners.

METHODS

Participants were 127 competitive female distance runners, aged 18-26, who provided at least some follow-up data in a randomized trial among 150 runners of the effects of oral contraceptives on bone health. After completing a baseline questionnaire and undergoing bone densitometry, they were followed an average of 1.85 yr.

RESULTS

Eighteen participants had at least one stress fracture during follow-up. Baseline characteristics associated (P<0.10) in multivariate analysis with stress fracture occurrence were one or more previous stress fractures (rate ratio [RR] [95% confidence interval]=6.42 (1.80-22.87), lower whole-body bone mineral content (RR=2.70 [1.26-5.88] per 1-SD [293.2 g] decrease), younger chronologic age (RR=1.42 [1.05-1.92] per 1-yr decrease), lower dietary calcium intake (RR=1.11 [0.98-1.25] per 100-mg decrease), and younger age at menarche (RR=1.92 [1.15-3.23] per 1-yr decrease). Although not statistically significant, a history of irregular menstrual periods was also associated with increased risk (RR=3.41 [0.69-16.91]). Training-related factors did not affect risk.

CONCLUSION

The results of this and other studies indicate that risk factors for stress fracture among young female runners include previous stress fractures, lower bone mass, and, although not statistically significant in this study, menstrual irregularity. More study is needed of the associations between stress fracture and age, calcium intake, and age at menarche. Given the importance of stress fractures to runners, identifying preventive measures is of high priority.

Disordered eating, menstrual irregularity, and bone mineral density in female runners

PURPOSE

To examine the relationships between disordered eating, menstrual irregularity, and low bone mineral density (BMD) in young female runners.

METHODS

Subjects were 91 competitive female distance runners aged 18-26 yr. Disordered eating was measured by the Eating Disorder Inventory (EDI). Menstrual irregularity was defined as oligo/amenorrhea (0-9 menses per year). BMD was measured by dual x-ray absorptiometry.

RESULTS

An elevated score on the EDI (highest quartile) was associated with oligo/amenorrhea, after adjusting for percent body fat, age, miles run per week, age at menarche, and dietary fat, (OR [95% CI]: 4.6 [1.1-18.6]). Oligo/amenorrheic runners had lower BMD than eumenorrheic runners at the spine (-5%), hip (-6%), and whole body (-3%), even after accounting for weight, percent body fat, EDI score, and age at menarche. Eumenorrheic runners with elevated EDI scores had lower BMD than eumenorrheic runners with normal EDI scores at the spine (-11%), with trends at the hip (-5%), and whole body (-5%), after adjusting for differences in weight and percent body fat. Runners with both an elevated EDI score and oligo/amenorrhea had no further reduction in BMD than runners with only one of these risk factors.

CONCLUSION

In young competitive female distance runners, (i) disordered eating is strongly related to menstrual irregularity, (ii) menstrual irregularity is associated with low BMD, and (iii) disordered eating is associated with low BMD in the absence of menstrual irregularity.

Oral contraceptives and bone mineral density in white and black women in CARDIA. Coronary Risk Development in Young Adults

To examine whether exposure to oral contraceptives (OCs) is associated with bone mineral density (BMD) in young women, we studied, cross-sectionally and longitudinally, 216 white and 260 black women enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Spine, hip and whole body BMDs were measured by dual-energy X-ray absorptiometry (DXA) when the women were aged 25-37 years, and whole body BMD was remeasured in 369 of the women 3 years later. A comprehensive history of OC use, including dose of ethinyl estradiol (estrogen) and duration of use, was determined from an interviewer-administered questionnaire. After adjustment for other relevant variables, we found that cumulative estrogen from OCs (mg) explained 4.0% of the variation in spine BMD ( p = 0.024) among white women, but did not explain any of the variance in BMD in black women. Cumulative OC estrogen was associated with a decreased risk for low bone density (lowest quartile) at the spine, hip and whole body in white women. The odds ratios (95% CIs) comparing women in the highest quartile of cumulative OC estrogen with those in the lowest quartile were, at the spine: 0.08 (0.02, 0.46); at the hip: 0.23 (0.06, 0.87); and at the whole body: 0.37 (0.11, 1.26). OC exposure was not related to low bone density in black women. OCs did not predict longitudinal changes in whole body BMD in either race. These results suggest that exposure to the estrogen from OCs during the premenopausal years may have a small beneficial effect on the skeleton in white women. Benefit is proportional to the cumulative estrogen exposure, suggesting that previous cross-sectional studies that considered OC use as a dichotomous variable may have lacked the power to detect an association.

Peer review of teaching in Web-based courses in nursing

With the explosion of college-level Web-based courses, concern has arisen about the quality of online courses. Peer review of online courses is one method of ensuring that these courses meet the highest standards. Although numerous colleges and universities use peer review for classroom presentations, clinical experiences, and course materials, peer review of an online course may require a different type of expertise. This article describes the process for conducting a peer review of teaching in Web-based courses and explains how documentation of peer review of an online course can be used for faculty development, promotion and tenure decisions, curriculum decisions, and program review.

Confirmatory serologic testing for acute toxoplasmosis and rate of induced abortions among women reported to have positive Toxoplasma immunoglobulin M antibody titers

OBJECTIVE

Results obtained with commercial testing kits for immunoglobulin M Toxoplasma antibodies may be inaccurate or may be inaccurately interpreted, which may influence whether a woman decides to terminate the pregnancy. This study was undertaken to determine whether confirmatory testing at a reference laboratory and communication of the results and an expert interpretation to the patient's physician would affect the rate of induced abortions among pregnant women with positive results of testing for immunoglobulin M Toxoplasma antibodies in outside laboratories.

STUDY DESIGN

This was a retrospective cohort study of 811 consecutive pregnant women for whom the toxoplasma serologic profile was performed at a reference laboratory. Almost all the patients had been informed by their physicians that a result of a test for immunoglobulin M Toxoplasma antibodies performed in an outside laboratory was positive. Women were separated into those with a toxoplasma serologic profile result suggestive of a recently acquired infection (group 1) and those with a result suggestive of an infection acquired in the more distant past (group 2). Physician reports of induced abortions were used to determine rates of induced abortion in groups 1 and 2.

RESULTS

Of the 811 women 321 (39.6%) were considered likely to have a recent infection (group 1) and 490 (60.4%) were considered likely to have a past infection (group 2). Physicians reported pregnancy outcomes for 433 (53.4%) of 811 women (65.1% and 45.7% in groups 1 and 2, respectively). Whereas 36 of 209 women in group 1 (17.2%) terminated the pregnancy, only 1 of 224 women in group 2 (0.4%) chose abortion (P <.001).

CONCLUSION

Confirmatory serologic testing in a reference laboratory and communication of the results and their correct interpretation by an expert to the patient's physician decreased the rate of unnecessary abortions by approximately 50% among women for whom positive immunoglobulin M Toxoplasma test results had been reported by outside laboratories.

Interactive videodisc instruction with undergraduate nursing students using cooperative learning strategies

This study was conducted to explore the use of interactive videodisc instruction (IVDI) with cooperative learning strategies. Baccalaureate students in their junior year were assigned to one of three types of groups based on prenursing grade point average: homogeneous average achievement, homogeneous high achievement, and heterogeneous mixed achievement students. Groups of three to five students viewed a lesson related to auscultation of heart sounds using IVDI and were videotaped throughout the lesson. There were no significant differences among the groups in their interaction frequencies, cooperativeness, or achievement on the group posttest completed immediately after viewing the lesson. Homogeneous high achievement students scored significantly higher than the other two groups on the individual posttests given 2 weeks after viewing the lesson. However, all three groups had very low scores. Several themes emerged related to management of the lesson. A majority of the students without previous IVDI experience had difficulty accessing and proceeding through the lesson: fill-in-the-blank questions posed by the lesson often were frustrating to the students, students in groups had difficulty reading the touch screen monitor, a large number of students attempted to locate the cardiac valves on themselves or other group members, and male students tended to distance themselves from each other. In this study, students needed more orientation to the computer equipment and to cooperative learning strategies. When using IVDI with inexperienced students, faculty should be certain that technical assistance is available throughout the lesson.