title: Vitamin D on Early Stages of Diabetic Kidney Disease: A Cross-sectional Study in Patients with Type 1 Diabetes Mellitus.
abstract: BACKGROUND
  Genetic and environmental factors are involved in the pathogenesis of type 1 diabetes mellitus (T1DM), and vitamin D (VD) deficiency appears as a candidate to risk factor for developing diabetic kidney disease (DKD).
  
  
  OBJECTIVE
  The purpose of study was to evaluate the existence of an association between low levels of VD and the presence and degree of DKD in T1DM.
  
  
  METHODS
  We performed a cross-sectional study, between November 2014 and December 2015. Levels of 25(OH)D and albuminuria were analyzed in 37 patients with T1DM and normal glomerular filtration rate. Thirty-six subjects were evaluated as a control group.
  
  
  RESULTS
  Patients with T1DM and hypovitaminosis D had higher levels of albuminuria compared to those with normal VD levels [albuminuria (log10) = 1.92 vs. 1.44;p< 0.05]. When we have separated the group of patients according to stage of DKD in patients with normo, micro, and macroalbuminuria, there are lower levels of 25(OH)D in the last when compared to the first two groups (26.7 ± 6.2, 24.8 ± 7.0, and 15.9 ± 7.6 ng/ml;p< 0.05, respectively). In T1DM group, we have found correlations between VD levels and both albuminuria and DKD stages (r= -0.5;p< 0.01 andr= -0.4;p< 0.05, respectively). A simple linear regression model, with albuminuria as the dependent variable and VD as an independent variable, showedr2= 0.2 andp< 0.01.
  
  
  CONCLUSIONS
  Our data suggest an association between reduced levels of VD and the presence and severity of DKD.
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: João Soares
authors.initials: JS
authors.lastname: Felício
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Rafael Mendonça
authors.initials: RM
authors.lastname: Luz
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Franciane Trindade Cunha
authors.initials: FT
authors.lastname: de Melo
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Fabricio
authors.initials: F
authors.lastname: de Souza Resende
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Alana Ferreira
authors.initials: AF
authors.lastname: de Oliveira
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Amanda Soares
authors.initials: AS
authors.lastname: Peixoto
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: João Felício
authors.initials: JF
authors.lastname: Abrahão Neto
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Carolina Tavares
authors.initials: CT
authors.lastname: Carvalho
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Denisson Dias
authors.initials: DD
authors.lastname: da Silva
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Marcia Costa
authors.initials: MC
authors.lastname: Dos Santos
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Natércia Neves Marques
authors.initials: NN
authors.lastname: de Queiroz
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Manuela Nascimento
authors.initials: MN
authors.lastname: de Lemos
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Elizabeth Sumi
authors.initials: ES
authors.lastname: Yamada
authors.affiliation: Endocrinology Division, University Hospital João de Barros Barreto, Federal University of Pará , Belém, Pará , Brazil.
authors.forename: Karem Miléo
authors.initials: KM
authors.lastname: Felício
keywords: 25(OH)D; albuminuria; diabetic kidney disease; type 1 diabetes mellitus; vitamin D