Background: In addition to genetic factors, environmental and lifestyle factors are thought to play an important role in the onset of adolescent idiopathic scoliosis (AIS). This cross-sectional study was conducted to explore lifestyle factors related to AIS.
Methods: This study included 2,759 Japanese female junior high school students who planned a secondary screening after an initial moiré topography screening indicated possible scoliosis. The students and their mothers, or guardians, were asked to fill out a questionnaire consisting of 38 questions about demographic factors, lifestyle-related factors, social factors, household environment, participation in sports, health status, and factors related to the mother’s pregnancy and delivery. The questionnaire was completed by 2,747 students (a 99.6% response rate). After excluding students with heart disease, neurological disease, or a congenital vertebral anomaly, 2,600 students were eligible for assessment. After undergoing a secondary screening with standing radiographs of the spine, students were assigned to the normal (control) group if radiographs showed a curve of <15° or to the scoliosis group if they had a curve of ≥15°. The odds ratios (ORs) for AIS in relation to the possible risk or preventive factors were estimated by logistic regression analyses.
Results: No lifestyle-related factor was significantly associated with AIS. However, AIS was associated with classical ballet training (OR, 1.38; 95% confidence interval [CI], 1.09 to 1.75); the odds of AIS developing increased as the child’s frequency of training, number of years of experience, and duration of training in ballet increased. The OR for AIS was 1.5 times higher for participants whose mothers had scoliosis. AIS was also associated with a low body mass index (BMI). These associations remained even after mutual adjustment was performed.
Conclusions: No association was found between AIS and lifestyle-related factors. However, classical ballet training, a family history of scoliosis, and low BMI may be associated with AIS.
Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
1Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
2National Institute for Environmental Studies, Ibaraki, Japan
3Department of Orthopedic Surgery, Juntendo University, Tokyo, Japan
4Department of Orthopedic Surgery, Kitasato University, Kanagawa, Japan
5Department of Orthopedic Surgery, Seirei Sakura Citizen Hospital, Chiba, Japan
6Department of Orthopedic Surgery, Zikei University, Tokyo, Japan
7Department of Orthopedic Surgery, Kitasato University, Kitasato Institute Hospital, Tokyo, Japan
8Department of Orthopedic Surgery, Saiseikai Chuo Hospital, Tokyo, Japan
9Tokyo Health Service Association, Tokyo, Japan
10Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan
11Division of Environmental and Occupational Health, Toho University, Tokyo, Japan
E-mail address for Y. Nishiwaki: firstname.lastname@example.org
* Kota Watanabe, MD, and Takehiro Michikawa, MD, contributed equally to the writing of this work.