{"id":872,"date":"2018-02-02T17:13:03","date_gmt":"2018-02-02T17:13:03","guid":{"rendered":"http:\/\/stadiasportsmedicine.com\/info\/?p=872"},"modified":"2018-02-02T17:13:46","modified_gmt":"2018-02-02T17:13:46","slug":"journal-club-review-iron-deficiency-and-stress-fracture-risk-for-females","status":"publish","type":"post","link":"https:\/\/stadiasportsmedicine.com\/info\/2018\/journal-club-review-iron-deficiency-and-stress-fracture-risk-for-females\/","title":{"rendered":"Journal Club Review: Iron Deficiency and Stress Fracture Risk for Females"},"content":{"rendered":"

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\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Prediction Model for Stress Fracture in Young Female Recruits During Basic Training.\u00a0 Moran DS et al.\u00a0 Med Sci Sports Exerc, 40(118):S636-644, 2008.<\/h6>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Association Between Hematological and Inflammatory Factors and Stress Fractures Among Female Military Recruits. Merkel D et al. Med Sci Sports Exerc, 40 (118):S691-697, 2008.<\/h6>\n

Iron deficiency is common among female athletes, with a reported incidence of between 12-40% in certain groups, with the incidence of anemia between 3-18%.\u00a0 These studies, both done on Israeli military recruits, raise some interesting questions about the association between iron deficiency and the risk for development of stress fractures in females.\u00a0 Military recruits are exposed to similar body stresses as endurance athletes, so there is some applicability to the Sports Medicine population.<\/p>\n

In the latter study, Merkel et al looked at 438 new military recruits, 227 female combatants, 83 male combatants and 128 female noncombatants.\u00a0 These subjects had their blood drawn for, among other things, hemoglobin and iron studies, including ferretin, serum iron and serum transferrin at induction, as well as two and four months into training.\u00a0 At induction, 18% of female inductees were anemic (defined as Hemoglobin < 12 g\/dL), compared with 8% of males (defined as Hb < 14 g\/dL).\u00a0 Iron deficiency, defined as a serum ferretin of 12 or less in females or 20 or less in males, was present in 40% of women, 6% of men.\u00a0 This was clearly a group that tended to iron deficiency, as the average hemoglobin among female combatants was 12.7 \u2013 a level that, in the presence of low iron stores probably represents a \u201crelative\u201d anemia (Hemoglobin in the normal range, but lower than the individual subject\u2019s healthy baseline).\u00a0 These subjects were subdivided based on their iron status (low or high) and then followed prospectively (observed as they progressed through their training).\u00a0 No changes in iron status during training were noted.\u00a0 As training progressed, recruits who presented back to the clinic with a diagnosis of stress fracture were identified (diagnosed by x-ray or bone scan).\u00a0 Over the observation period, 12% of female combatants presented with a stress fracture.\u00a0 No males or noncombatant females developed stress fractures.\u00a0\u00a0 Female combatants with a stress fracture were found to have statistically lower levels of serum iron and iron saturation.\u00a0 Ferretin, which is an indicator of iron stores in the body, did not differ between recruits with or without stress fractures.\u00a0 This may be related to the fact that ferretin tends to increase during times of stress on the body, rising relatively more in the injured group.\u00a0 This study shows an association \u2013 not necessarily cause.\u00a0 It may be that poor nutrition leading to decreased body iron stores occurs in parallel with decreased calcium intake, leading to a higher risk for stress fracture.\u00a0 Alternatively, the inflammation associated with the development of stress fractures could suppress iron stores through effects on the liver.<\/p>\n

Based on this association, Moran et al. looked at ways of using iron status, among other variables, to predict the risk for development of stress fracture in military recruits during a four-month basic training period.\u00a0 In this study, 227 female and 83 male basic training recruits were assessed at baseline, two months, four months and 16 months after induction.\u00a0 Among variables analyzed were iron status, bone quality, fitness, nutrition, activity patterns, etc.\u00a0 Over one year of training, stress fractures were diagnosed through the use of bone scan or MRI.\u00a0 The researchers then collated the data obtained in these subjects and developed prediction equations to try to predict the risk of development of stress fracture.\u00a0 The final equation developed successfully predicted the development of a stress fracture 76.5% of the time.\u00a0 Risk factors identified as significant for the development of stress fracture over time included being tall, \u201clean,\u201d feeling \u201cburned out,\u201d having an iron deficiency, with a high normal ferretin.\u00a0 This again speaks to the fact that ferretin levels will often rise in the presence of body injury.\u00a0 Some coaches and clinicians advocate following serum ferretin during the course of the season, but these studies, and others like them, argue against that, as an increase in ferretin over time does not necessarily reflect increasing amounts of body iron stores, but may simply reflect increased stress.<\/p>\n

What these studies do suggest, however, is that it is reasonable to check iron status on female endurance athletes, particularly those who are new to their sport or who are increasing the level of their involvement in their sport.\u00a0 Athletes with low iron levels should be supplemented if there is associated anemia (or relative anemia), and also monitored for development of stress fractures, with efforts made at risk reduction before an injury occurs.\u00a0 If you are starting a running program or are considering doing so, consider giving us a call to talk about risk assessment and risk reduction.\u00a0 It might protect you from injury, or if anemia is present, even improve your performance.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Prediction Model for Stress Fracture in Young Female Recruits During Basic Training.\u00a0 Moran DS et al.\u00a0 Med Sci Sports […]<\/p>\n","protected":false},"author":4,"featured_media":873,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[75],"tags":[15,141,38,64,136,77],"class_list":["post-872","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sport-med-research","tag-injury-prevention","tag-journal-club","tag-leg-pain","tag-nutrition","tag-research","tag-sports-medicine"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/posts\/872","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/comments?post=872"}],"version-history":[{"count":1,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/posts\/872\/revisions"}],"predecessor-version":[{"id":874,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/posts\/872\/revisions\/874"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/media\/873"}],"wp:attachment":[{"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/media?parent=872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/categories?post=872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stadiasportsmedicine.com\/info\/wp-json\/wp\/v2\/tags?post=872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}