title: Evaluating the Risk of a Fifth Metatarsal Stress Fracture by Measuring the Serum 25-Hydroxyvitamin D Levels.
abstract: BACKGROUND
  The fifth metatarsal bone is a common site of stress fractures in soccer athletes. Although several endocrine risk factors for stress fractures have been proposed, the endocrine risks for fifth metatarsal (5-MT) stress fractures have not been evaluated.
  
  
  METHODS
  To evaluate the endocrine risks of fifth metatarsal stress fractures, we conducted a cumulative case-control study. The present study included 37 athletes, of which 18 had a history of a zone 2 or zone 3 fifth metatarsal stress fracture and 19 controls. We analyzed serum 25-hydroxyvitamin D (25-OHD), serum parathyroid hormone (PTH), as well as biochemical markers of bone turnover by univariate or multivariate analyses.
  
  
  RESULTS
  Logistic regression analyses adjusted for multiple confounders revealed that insufficient serum 25-OHD levels less than 30 ng/mL (odds ratio [OR], 23.3), higher serum PTH levels (OR, 1.01), or higher serum bone-specific isoform of alkaline phosphatase levels (OR, 1.10) rather than serum tartrate-resistant acid phosphatase 5b were associated with statistically significantly increased odds of 5-MT stress fractures. A postestimation calculation demonstrated that 25-OHD levels of 10 and 20 ng/mL were associated with 5.1 and 2.9 times greater odds for 5-MT stress fractures, respectively.
  
  
  CONCLUSIONS
  25-OHD insufficiency was associated with an increased incidence of 5-MT stress fractures. This insight may be useful for intervening to prevent 5-MT stress fractures.
  
  
  METHODS
  Level III, case-control study.
authors.affiliation: School of Health and Sports Science, Juntendo University, Chiba, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shimasaki
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Nerima Hospital, Tokyo, Japan nagao@juntendo.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Nagao
authors.affiliation: Department of Nursing and Rehabilitation Science, School of Physical Therapy at Odawara, International University of Health and Sports Science, Kanagawa, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Miyamori
authors.affiliation: School of Health and Sports Science, Juntendo University, Chiba, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Aoba
authors.affiliation: Institute of Physical Education, Keio University, Kanagawa, Japan.
authors.forename: Norifumi
authors.initials: N
authors.lastname: Fukushi
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Hospital, Tokyo, Japan.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Saita
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Hospital, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Nerima Hospital, Tokyo, Japan.
authors.forename: Sung-Gon
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Nerima Hospital, Tokyo, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nozawa
authors.affiliation: Department of Orthopedic Surgery, Juntendo University Hospital, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
authors.affiliation: School of Health and Sports Science, Juntendo University, Chiba, Japan Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yoshimura
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D056352:Athletes; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015775:Fractures, Stress / Q000097:blood* / Q000209:etiology*; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008682:Metatarsal Bones / Q000293:injuries*; D010281:Parathyroid Hormone / Q000097:blood; D018570:Risk Assessment; D000071681:Tartrate-Resistant Acid Phosphatase / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase
keywords: fifth metatarsal stress fracture; soccer athletes; vitamin D