title: Vitamin D deficiency as a risk factor for cystic fibrosis-related diabetes in the Scandinavian Cystic Fibrosis Nutritional Study.
abstract: OBJECTIVE
  Many cystic fibrosis patients are vitamin D-insufficient. Cystic fibrosis-related diabetes is a major complication of cystic fibrosis. The literature suggests that vitamin D might possess certain glucose-lowering properties. We aimed to assess the relationship between vitamin D and cystic fibrosis-related glucose intolerance.
  
  
  METHODS
  We enrolled 898 cystic fibrosis patients from Sweden, Norway and Denmark. Vitamin D intake was assessed using a seven-day food record. Serum 25-hydroxyvitamin D (s25OHD) and HbA(1c) were measured, and an OGTT was carried out. Multiple linear and logistic regressions were used for HbA(1c) and cystic fibrosis-related diabetes/OGTT result as outcome variables, respectively. Each model was controlled for country, and for known cystic fibrosis-related diabetes risk factors: age, sex, genotype, liver dysfunction, long-term corticosteroid treatment, and lung and pancreatic function.
  
  
  RESULTS
  Degree of vitamin D insufficiency (OR 1.36; p = 0.032) and s25OHD < 30 nmol/l (OR 1.79; p = 0.042) were significant risk factors for cystic fibrosis-related diabetes. Accordingly, HbA(1c) value was positively associated with s25OHD < 30 nmol/l and < 50 nmol/l, as well as with degree of vitamin D insufficiency (adjusted R (2) = 20.5% and p < 0.05 in all). In subgroup analyses, s25OHD < 30 nmol/l determined the HbA(1c) value in paediatric patients (adjusted R (2) = 20.2%; p = 0.017), but not in adults.
  
  
  CONCLUSIONS
  Vitamin D status is associated with HbA(1c) and diabetes in cystic fibrosis, particularly in children. The study justifies prospective studies on the proposed role of vitamin D deficiency in the pathophysiology of diabetes mellitus.
authors: Stockholm CF Centre, B 59, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden. Terezia.Pincikova@ki.se
authors: T
authors: T
authors: Pincikova
authors: K
authors: K
authors: Nilsson
authors: I E
authors: IE
authors: Moen
authors: G
authors: G
authors: Fluge
authors: A
authors: A
authors: Hollsing
authors: P K
authors: PK
authors: Knudsen
authors: A
authors: A
authors: Lindblad
authors: L
authors: L
authors: Mared
authors: T
authors: T
authors: Pressler
authors: L
authors: L
authors: Hjelte
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000097:blood / Q000150:complications*; D003920:Diabetes Mellitus / Q000209:etiology*; D015930:Diet Records; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D012307:Risk Factors; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D012720:Severity of Illness Index; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications*; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; D014807:Vitamin D; C517652:hemoglobin A1c protein, human