Evidence map›Paper›PMID 41669996›Full record

Observational studyPM & R : the journal of injury, function, and rehabilitation2026

Differences in female athlete triad risk factors between Japanese and American female runners: A comparative study.

Ana Carla C Salamunes, Natsue Koikawa, Nancy I Williams, Kristen J Koltun, Maha L Vijaya Krishnan, Yuko Sakurama, Takao Matsuda, Shihoko Suzuki, Yuji Takazawa, Mary Jane De Souza

Abstract readComparative StudyObservational StudyMulticenter Study
In one paragraph

Observational study in PM & R : the journal of injury, function, and rehabilitation, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Ana Carla C SalamunesWomen's Health and Exercise Lab, Pennsylvania State University, University Park, Pennsylvania, USA.
Natsue KoikawaJapanese Center for Research on Women in Sport, Juntendo University, Tokyo, Japan.
Nancy I WilliamsWomen's Health and Exercise Lab, Pennsylvania State University, University Park, Pennsylvania, USA.
Kristen J KoltunNeuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Maha L Vijaya KrishnanWomen's Health and Exercise Lab, Pennsylvania State University, University Park, Pennsylvania, USA.
Yuko SakuramaJapanese Center for Research on Women in Sport, Juntendo University, Tokyo, Japan.
Takao MatsudaDepartment of Gynecology, National Hospital Organization, Nishi-Beppu National Hospital, Oita, Japan.
Shihoko SuzukiFaculty of Health and Social Services, Kanagawa University of Human Services, Kanagawa, Japan.
Yuji TakazawaDepartment of Orthopaedics Surgery, Faculty of Medicine, Juntendo University, Tokyo, Japan.
Mary Jane De SouzaWomen's Health and Exercise Lab, Pennsylvania State University, University Park, Pennsylvania, USA.

Funding

Japan Sports Agency (an agency of the Ministry of Education, Culture, Sports, Science and Technology, Japan)
6 · The paper itself

Abstract

backgroundDifferences in female athlete triad risk factors between runners from Japan and the United States have not been explored.

objectiveTo compare the prevalence of Triad risk factors and Triad components between female Japanese and American distance runners.

designObservational, cross-sectional.

settingTwo universities; one in the United States and one in Japan.

participantsA total of 77 female runners: 36 Japanese middle- and long-distance runners, and 41 American distance runners.

interventionsNot applicable.

main outcome measuresTriad components were energy deficiency, menstrual disturbances, and poor bone health. Triad risk factors were, respectively for each component: body mass index, serum total triiodothyronine, and history of diagnosed eating disorders; delayed menarche, history of menstrual irregularity, and current oligoamenorrhea; and bone mineral density and history of stress fractures. Prevalence was compared with chi-square and Fisher's exact tests. Group differences were assessed with t-tests and Mann-Whitney U tests. Data are mean difference (95% confidence interval [CI]).

resultsJapanese runners had lower body weight (-4.15 [95% CI, -7.03.to -1.27] kg, p = .005) and percentage of body fat (-5.2 [95% CI, -6.9 to -3.5] %, p < .001) than American runners, with no differences in body mass index, serum total triiodothyronine, age of menarche, or menstrual cycle length (p > .05). Japanese runners had significantly lower bone mineral density at the lumbar spine (-0.195 [95% CI, -0.246 to -0.143] g/cm

conclusionsJapanese female runners may be at a higher Triad risk than American peers, given their higher prevalence of energy deficiency risk factors, history of stress fractures, and of athletes experiencing all Triad components.

Indexed as

Female Athlete Triad SyndromeRunningAdultBody Mass IndexBone DensityCross-Sectional StudiesEast Asian PeopleFemaleHumansJapanNorth American PeoplePrevalenceRisk FactorsUnited StatesYoung Adult

Identifiers

PMID41669996
PMCPMC13193434

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.