title: Decreased vitamin D levels in children with familial Mediterranean fever.
abstract: OBJECTIVE
  To determine the frequency of vitamin D deficiency in children with familial Mediterranean fever (FMF) and to investigate the factors associated with low vitamin D status.
  
  
  METHODS
  Forty-four patients with FMF and 39 age- and sex-matched healthy controls were enrolled in this study. Demographic data, FMF symptoms, disease duration, time to delay for diagnosis, duration of follow-up, disease severity score, MEFV gene mutation, cumulative colchicine dose, compliance to treatment and serum C-reactive protein levels were recorded for each patient. Serum 25-hydroxyvitamin D levels were measured by an original commercial kit based on chemiluminescent microparticle immunoassay (CMIA).
  
  
  RESULTS
  The serum 25-hydroxyvitamin D levels were significantly lower in FMF patients than the healthy controls (12.9 ± 3.6 and 16.3 ± 5.5 ng/mL, respectively, P = 0.001). Vitamin D levels were similar in patients homozygous for M694V and other genotypes (11.8 ± 3.7 and 13.2 ± 3.6 ng/mL, respectively, P = 0.21). Stepwise multiple linear regression analysis confirmed that the cumulative colchicine dose was the strongest independent variable correlating with vitamin D levels (r(2) = 0.194, P = 0.001).
  
  
  CONCLUSIONS
  Our results suggest that serum 25-hydroxyvitamin D levels are decreased in children with FMF. Cumulative colchicine dose appears to negatively affect vitamin D levels. The role of colchicine on vitamin D metabolism needs to be elicited.
authors.affiliation: Department of Pediatric Endocrinology, Dokuz Eylul University Hospital, Izmir, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Anık
authors.forename: Gönül
authors.initials: G
authors.lastname: Catlı
authors.forename: Balahan
authors.initials: B
authors.lastname: Makay
authors.forename: Ayhan
authors.initials: A
authors.lastname: Abacı
authors.forename: Tuncay
authors.initials: T
authors.lastname: Küme
authors.forename: Erbil
authors.initials: E
authors.lastname: Unsal
authors.forename: Ece
authors.initials: E
authors.lastname: Böber
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D003078:Colchicine / Q000627:therapeutic use; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003598:Cytoskeletal Proteins / Q000235:genetics; D010505:Familial Mediterranean Fever / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009154:Mutation / Q000235:genetics; D015995:Prevalence; D000071198:Pyrin; D012720:Severity of Illness Index; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D003598:Cytoskeletal Proteins; C000604192:MEFV protein, human; D000071198:Pyrin; D014807:Vitamin D; D002097:C-Reactive Protein; D003078:Colchicine
keywords: 25-hydroxyvitamin D; children; colchicine; familial Mediterranean fever