title: Risk factors for hypovitaminosis D in nondialyzed chronic kidney disease patients.
abstract: BACKGROUND
  Hypovitaminosis D is highly prevalent among patients with chronic kidney disease and has been associated with worse outcome even in the earlier stages of the disease.
  
  
  OBJECTIVE
  This study aimed to investigate the risk factors for hypovitaminosis D in nondialyzed patients with chronic kidney disease.
  
  
  METHODS
  This cross-sectional study included 120 patients with chronic kidney disease at stages 2 to 5 (62% male, age: 55.4 ± 11.3 year, estimated glomerular filtration rate: 35.1 ± 15 mL/minute, body mass index [BMI]: 27.1 ± 5.2 kg/m(2), 31% diabetics). Serum 25-hydroxivitamin D [25(OH)D] was measured by chemiluminescence. Subjective global assessment, total body fat (dual-energy X-ray absorptiometry), visceral and subcutaneous abdominal fat (computed tomography), and several laboratory parameters were assessed.
  
  
  RESULTS
  Insufficiency of 25(OH)D (15 to 30 ng/mL) was observed in 55% and deficiency (<15 ng/mL) in 20% of the patients. Patients with diabetes, BMI ≥30 kg/m(2), and who had the blood collection during the winter or spring had lower levels of 25(OH)D. Serum 25(OH)D correlated inversely with parathyroid hormone, proteinuria, insulin resistance, leptin, and subcutaneous abdominal fat. The risk factors for hypovitaminosis D were diabetes (odds ratio: 3.8; 95% CI: 1.2 to 11.7; P = .022) and BMI ≥30 kg/m(2) (odds ratio: 4.3; 95% CI: 1.2 to 15.3; P = .018). In the logistic regression analysis adjusting for gender, skin color, and season of the year, diabetes and BMI ≥30 kg/m(2) were independently associated with hypovitaminosis D.
  
  
  CONCLUSIONS
  Diabetes and obesity were the risk factors for hypovitaminosis D in nondialyzed patients with chronic kidney disease. Effective interventional protocols of vitamin D supplementation taking into account these risk factors are warranted for this population.
authors.affiliation: Nutrition Program, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Vilani
authors.initials: V
authors.lastname: Figuiredo-Dias
authors.forename: Lilian
authors.initials: L
authors.lastname: Cuppari
authors.forename: Miriam Ghedini
authors.initials: MG
authors.lastname: Garcia-Lopes
authors.forename: Aluízio Barbosa
authors.initials: AB
authors.lastname: de Carvalho
authors.forename: Sergio Antonio
authors.initials: SA
authors.lastname: Draibe
authors.forename: Maria Ayako
authors.initials: MA
authors.lastname: Kamimura
mesh_terms: D000328:Adult; D000368:Aged; D050218:Body Fat Distribution; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D048909:Diabetes Complications; D019587:Dietary Supplements; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007333:Insulin Resistance; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000503:physiopathology; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D010281:Parathyroid Hormone / Q000097:blood; D012307:Risk Factors; D012621:Seasons; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000209:etiology*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D