Risk factors for metabolic bone disease in Crohn's disease patients.
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.
Cravo
Marília
M
Instituto Português de Oncologia Francisco Gentil, Lisboa, Portugal. marilia.cravo@sapo.pt
Guerreiro
Catarina Sousa
CS
dos Santos
Paula Moura
PM
Brito
Miguel
M
Ferreira
Paula
P
Fidalgo
Catarina
C
Tavares
Lourdes
L
Pereira
António Dias
AD
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
D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha