title: Risk factors for metabolic bone disease in Crohn's disease patients.
abstract: BACKGROUND
  The aim was to evaluate the presence of metabolic bone disease (MBD) in patients with Crohn's disease (CD) and to identify potential etiologic factors.
  
  
  METHODS
  The case-control study included 99 patients with CD and 56 controls with a similar age and gender distribution. Both groups had dual-energy x-ray absorptionmetry and a nutritional evaluation. Single nucleotide polymorphisms at the IL1, TNF-α, LTα, and IL-6 genes were analyzed in patients only. Statistical analysis was performed using SPSS software.
  
  
  RESULTS
  The prevalence of MBD was significantly higher in patients (P = 0.006). CD patients with osteoporosis were older (P < 0.005), small bowel involvement and surgical resections were more frequent (P < 0.005), they more often exhibited a penetrating or stricturing phenotype (P < 0.05), duration of disease over 15 years (P < 0.005), and body mass index (BMI) under 18.5 kg/m(2) (P < 0.01) were more often found. No association was found with steroid use. Patients with a Z-score < -2.0 more frequently had chronic active disease (P < 0.05). With regard to diet, low vitamin K intake was more frequent (P = 0.03) and intake of total, monounsaturated, and polyunsaturated fat was higher in patients with Z-score < -2.0 (P < 0.05). With respect to genetics, carriage of the polymorphic allele for LTα252 A/G was associated with a higher risk of osteoporosis (P = 0.02). Regression analysis showed that age over 40 years, chronic active disease, and previous colonic resections were independently associated with the risk of developing MBD.
  
  
  CONCLUSIONS
  The prevalence of MBD was significantly higher in CD patients. Besides the usual risk factors, we observed that factors related to chronic active and long-lasting disease increased the risk of MBD.
authors.affiliation: Instituto Português de Oncologia Francisco Gentil, Lisboa, Portugal. marilia.cravo@sapo.pt
authors.forename: Marília
authors.initials: M
authors.lastname: Cravo
authors.forename: Catarina Sousa
authors.initials: CS
authors.lastname: Guerreiro
authors.forename: Paula Moura
authors.initials: PM
authors.lastname: dos Santos
authors.forename: Miguel
authors.initials: M
authors.lastname: Brito
authors.forename: Paula
authors.initials: P
authors.lastname: Ferreira
authors.forename: Catarina
authors.initials: C
authors.lastname: Fidalgo
authors.forename: Lourdes
authors.initials: L
authors.lastname: Tavares
authors.forename: António Dias
authors.initials: AD
authors.lastname: Pereira
mesh_terms: D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000473:pathology; D016022:Case-Control Studies; D003424:Crohn Disease / Q000150:complications* / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics; D012307:Risk Factors; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha