title: Association between body mass index, body height, and the prevalence of spinal deformities.
abstract: BACKGROUND
  The most common spinal deformities among adolescents are adolescent idiopathic scoliosis (AIS; 2%-3% prevalence) and Scheuermann kyphosis (SK; 1%-8% prevalence). Both are believed to have a genetic influence in their etiology. The association between body mass index (BMI) and body stature and their possible association to spinal deformities is uncertain.
  
  
  METHODS
  A cross-sectional prevalence study.
  
  
  OBJECTIVE
  To examine the prevalence of all adolescent spinal deformities according to the extent of their severity as well as their possible association to BMI and body height.
  
  
  METHODS
  Subjects diagnosed as having spinal deformities were classified into one of three severity groups; "Mild," "Intermediate," or "Severe," according to their curve scoliosis or kyphosis measurement with a standing X-ray.
  
  
  METHODS
  The data for this study were derived from a medical database containing records of 17-year-old male and female patients before their recruitment into mandatory military service. Information on the disability codes associated with spinal deformities according to the Regulations of Medical Fitness Determination was retrieved. Logistic regression models were used to assess the association between the BMI and body height to various degrees of spinal deformities by severity.
  
  
  RESULTS
  The study cohort included 829,791 consecutive subjects, of whom 103,249 were diagnosed with spinal deformities (76% were mild in degree). The prevalence of spinal deformities was significantly greater among the underweight male and female patients (p<.001). Increased BMI had a protective effect for developing spinal deformities. The odds ratios for severe spinal deformities were greater compared with mild spinal deformities in the underweight groups. The risk for developing spinal deformities increased significantly with height for both genders (p<.001).
  
  
  CONCLUSIONS
  An association between height and the risk for spinal deformities by severity was found for all height groups. Below normal BMI is associated with severity of spinal deformities, whereas above-normal BMI apparently has a protective effect. Body height is also positively associated with the severity of spinal deformities.
authors: Department of Orthopedic Surgery, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel; Medical Corps, Israeli Defense Forces, Israel. Electronic address: oded_he@yahoo.com.
authors: Oded
authors: O
authors: Hershkovich
authors: Department of Orthopedic Surgery, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel.
authors: Alon
authors: A
authors: Friedlander
authors: Medical Corps, Israeli Defense Forces, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801 Israel.
authors: Barak
authors: B
authors: Gordon
authors: Department of Orthopedic Surgery, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel.
authors: Harel
authors: H
authors: Arzi
authors: Medical Corps, Israeli Defense Forces, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801 Israel.
authors: Estela
authors: E
authors: Derazne
authors: Medical Corps, Israeli Defense Forces, Israel.
authors: Dorit
authors: D
authors: Tzur
authors: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801 Israel; Central Management, Chaim Sheba Medical Center, Tel Hashomer, 52621 Israel.
authors: Ari
authors: A
authors: Shamiss
authors: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6997801 Israel.
authors: Arnon
authors: A
authors: Afek
mesh_terms: D000293:Adolescent; D001827:Body Height / Q000502:physiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D010808:Physical Examination; D015995:Prevalence; D012307:Risk Factors; D012600:Scoliosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D013851:Thinness / Q000503:physiopathology*
keywords: Adolescents; Body mass index (BMI); Height; Obesity; Overweight; Scheuermann kyphosis; Scoliosis; Spinal deformities; Underweight