title: Legg-Calve-Perthes disease and risks for cardiovascular diseases and blood diseases.
abstract: OBJECTIVE
  We hypothesized that patients with Legg-Calvé-Perthes disease (LCPD) might have higher risks of cardiovascular and blood diseases.
  
  
  METHODS
  A total of 3141 patients, 2 to 15 years of age, with LCPD diagnosed between 1965 and 2005 were identified with the Swedish Inpatient Register. A total of 15 595 individuals without LCPD were selected randomly from among the Swedish general population, with matching according to year of birth, age, gender, and region of residence. Cox proportional-hazard regression analyses, with adjustment for socioeconomic index, were used to estimate relative risks. The patients also were compared with their same-gender siblings.
  
  
  RESULTS
  Patients with LCPD had a hazard ratio (HR) of 1.70 (95% confidence interval [CI]: 1.39-2.09) for cardiovascular diseases, compared with individuals without LCPD. The point estimate was slightly higher among subjects >30 years of age at the follow-up (HR: 2.10 [95% CI: 1.52-2.91]). There were statistically significantly higher risks for blood diseases, including anemias and coagulation defects (HR: 1.41 [95% CI: 1.07-1.86]), which were more pronounced among subjects >30 years of age at the follow-up (HR: 2.70 [95% CI: 1.50-4.84]). Patients also had statistically significantly higher risks of hypertensive disease (HR: 2.97 [95% CI: 1.87-4.72]) and nutritional anemia (HR: 2.92 [95% CI: 1.58-5.40]). Analyses using siblings as the comparison group showed consistent results for cardiovascular diseases.
  
  
  CONCLUSIONS
  The results are consistent with the hypothesis that an insufficient blood supply to the femoral head, attributable to vascular pathologic conditions, is involved in the pathogenesis of LCPD.
authors.affiliation: Uppsala University Hospital, Department of Orthopaedics, SE-75185 Uppsala, Sweden. yasmin.hailer@surgsci.uu.se
authors.forename: Yasmin D
authors.initials: YD
authors.lastname: Hailer
authors.forename: Scott M
authors.initials: SM
authors.lastname: Montgomery
authors.forename: Anders
authors.initials: A
authors.lastname: Ekbom
authors.forename: Olof S
authors.initials: OS
authors.lastname: Nilsson
authors.forename: Shahram
authors.initials: S
authors.lastname: Bahmanyar
mesh_terms: D000293:Adolescent; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000098:blood supply*; D006402:Hematologic Diseases / Q000453:epidemiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007873:Legg-Calve-Perthes Disease / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D017202:Myocardial Ischemia / Q000453:epidemiology; D016016:Proportional Hazards Models; D012039:Regional Blood Flow; D012959:Socioeconomic Factors