title: Vitamin D deficiency and persistent proteinuria among HIV-infected and uninfected injection drug users.
abstract: OBJECTIVE
  Proteinuria occurs commonly among HIV-infected and uninfected injection drug users (IDUs) and is associated with increased mortality risk. Vitamin D deficiency, highly prevalent among IDUs and potentially modifiable, may contribute to proteinuria. To determine whether vitamin D is associated with proteinuria in this population, we conducted a cross-sectional study in the AIDS Linked to the IntraVenous Experience (ALIVE) Study.
  
  
  METHODS
  25(OH)-vitamin D levels were measured in 268 HIV-infected and 614 HIV-uninfected participants. The association between vitamin D deficiency (<10  ng/ml) and urinary protein excretion was evaluated by linear regression. The odds of persistent proteinuria (urine protein-to-creatinine ratio >200  mg/g on two occasions) associated with vitamin D deficiency was examined using logistic regression.
  
  
  RESULTS
  One-third of participants were vitamin D-deficient. Vitamin D deficiency was independently associated with higher urinary protein excretion (P < 0.05) among HIV-infected and diabetic IDUs (P-interaction < 0.05 for all). Persistent proteinuria occurred in 18% of participants. Vitamin D deficiency was associated with greater than six-fold odds of persistent proteinuria among diabetic IDUs [odds ratio (OR) 6.29, 95% confidence interval (CI) 1.54, 25.69] independent of sociodemographic characteristics, comorbid conditions, body mass index, and impaired kidney function [estimated glomerular filtration rate (eGFR) <60  ml/min per 1.73  m(2)]; no association, however, was observed among nondiabetic IDUs (OR 1.06, 95% CI 0.64, 1.76) (P-interaction <0.05).
  
  
  CONCLUSIONS
  Vitamin D deficiency was associated with higher urinary protein excretion among those with HIV infection and diabetes. Vitamin D deficiency was independently associated with persistent proteinuria among diabetic IDUs, although not in nondiabetic persons. Whether vitamin D repletion ameliorates proteinuria in these patients requires further study.
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. mestrel1@jhmi.edu
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Estrella
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Kirk
authors.forename: Shruti H
authors.initials: SH
authors.lastname: Mehta
authors.forename: Todd T
authors.initials: TT
authors.lastname: Brown
authors.forename: Derek M
authors.initials: DM
authors.lastname: Fine
authors.forename: Mohamed G
authors.initials: MG
authors.lastname: Atta
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Lucas
mesh_terms: D016263:AIDS-Associated Nephropathy / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014808:Vitamin D Deficiency / Q000150:complications* / Q000453:epidemiology