title: Prevalence of Hypertension in Pediatric Tibia Vara and Slipped Capital Femoral Epiphysis.
abstract: BACKGROUND
  Slipped capital femoral epiphysis (SCFE) and tibia vara (Blount disease) are associated with childhood obesity. However, the majority of obese children do not develop SCFE or tibia vara. Therefore, it is hypothesized that other obesity-related biological changes to the physis, in addition to increased biomechanical stress, potentiate the occurrence of SCFE and tibia vara. Considering that hypertension can impose pathologic changes in the physis similar to those observed in these obesity-related diseases we set out to determine the prevalence of hypertension in patients with SCFE and tibia vara.
  
  
  METHODS
  Blood pressure measurements were obtained in 44 patients with tibia vara and 127 patients with SCFE. Body mass index and blood pressure were adjusted for age, sex, and height percentiles utilizing normative distribution data from the CDC. These cohorts were compared with age-matched and sex-matched cohorts derived from an obesity clinic who did not have either bone disease. A multivariable proportional odds model was used to determine association.
  
  
  RESULTS
  The prevalence of prehypertension/hypertension was significantly higher in the tibia vara (64%) and SCFE cohort (64%) compared with respective controls (43%). Patients diagnosed with either SCFE or tibia vara had 2.5-fold higher odds of having high blood pressure compared with age-matched and sex-matched obese patients without bone disease. Sex, age, and race did not have a significant effect on a patient's blood pressure.
  
  
  CONCLUSIONS
  This is the first study to establish that the obesity-related bone diseases, SCFE and tibia vara, are significantly associated with high blood pressure. These data have immediate clinical impact as they demonstrate that children with obesity-related developmental bone disease have increased prevalence of undiagnosed and untreated hypertension. Furthermore, this prevalence study supports the hypothesis that hypertension in conjunction with increased biomechanical forces together potentiate the occurrence of SCFE and tibia vara. If proven true, it is plausible that hypertension may represent a modifiable risk factor for obesity-related bone disease.
  
  
  METHODS
  Level III-case-control study.
authors.affiliation: *Vanderbilt Orthopedic Institute, Monroe Carell Jr. Children's Hospital, Nashville, TN †University of Kentucky and Shriners Hospitals for Children, Lexington, KY.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Taussig
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Powell
authors.forename: Heather A
authors.initials: HA
authors.lastname: Cole
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Nwosu
authors.forename: Tray
authors.initials: T
authors.lastname: Hunley
authors.forename: Spencer E
authors.initials: SE
authors.lastname: Romine
authors.forename: Henry
authors.initials: H
authors.lastname: Iwinski
authors.forename: Vishwas
authors.initials: V
authors.lastname: Talwalkar
authors.forename: Tracy
authors.initials: T
authors.lastname: Warhoover
authors.forename: Steven A
authors.initials: SA
authors.lastname: Lovejoy
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Mencio
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Martus
authors.forename: Janet
authors.initials: J
authors.lastname: Walker
authors.forename: Todd
authors.initials: T
authors.lastname: Milbrandt
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Schoenecker
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D001848:Bone Diseases, Developmental / Q000150:complications* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D055034:Osteochondrosis / Q000150:complications / Q000151:congenital* / Q000503:physiopathology; D015995:Prevalence; D012307:Risk Factors; D060048:Slipped Capital Femoral Epiphyses / Q000150:complications* / Q000503:physiopathology; D014481:United States / Q000453:epidemiology