Evaluating the Risk of a Fifth Metatarsal Stress Fracture by Measuring the Serum 25-Hydroxyvitamin D Levels
Foot & Ankle International November 23, 2015 1071100715617042
Yu Shimasaki, MSc1
Masashi Nagao, MD, PhD2⇑
Takayuki Miyamori, MPthy3
Yukihiro Aoba, MSc1
Norifumi Fukushi, MSc4
Yoshitomo Saita, MD, PhD5
Hiroshi Ikeda, MD, PhD5
Sung-Gon Kim, MD, PhD2
Masahiko Nozawa, MD, PhD2
Kazuo Kaneko, MD, PhD5
Masafumi Yoshimura, PhD1,6
1 School of Health and Sports Science, Juntendo University, Chiba, Japan
2 Department of Orthopedic Surgery, Juntendo University Nerima Hospital, Tokyo, Japan
3 Department of Nursing and Rehabilitation Science, School of Physical Therapy at Odawara, International University of Health and Sports Science, Kanagawa, Japan
4 Institute of Physical Education, Keio University, Kanagawa, Japan
5 Department of Orthopedic Surgery, Juntendo University Hospital, Tokyo, Japan
6 Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
Masashi Nagao, MD, PhD, Department of Orthopedic Surgery, Juntendo University Nerima Hospital, 3-1-10 Takanodai, Nerima-ku, Tokyo, 177-8521, Japan. Email:firstname.lastname@example.org
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.
Conclusion: 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.
Level of Evidence: Level III, case-control study.