title: Association of low serum 25-hydroxyvitamin D levels and acute kidney injury in the critically ill.
abstract: OBJECTIVE
  Given the importance of inflammation in acute kidney injury and the relationship between vitamin D and inflammation, we sought to elucidate the effect of vitamin D on acute kidney injury. We hypothesized that deficiency in 25-hydroxyvitamin D prior to hospital admission would be associated with acute kidney injury in the critically ill.
  
  
  METHODS
  Two-center observational study of patients treated in medical and surgical intensive care units.
  
  
  METHODS
  Two hundred nine medical and surgical intensive care beds in two teaching hospitals in Boston, Massachusetts.
  
  
  METHODS
  Two thousand seventy-five patients, aged ≥ 18 yrs, in whom serum 25-hydroxyvitamin D was measured prior to hospitalization between 1998 and 2009.
  
  
  METHODS
  : None.
  
  
  RESULTS
  The exposure of interest was preadmission serum 25-hydroxyvitamin D and categorized a priori as deficiency (25-hydroxyvitamin D <15 ng/mL), insufficiency (25-hydroxyvitamin D 15-30 ng/mL), or sufficiency (25-hydroxyvitamin D ≥ 30 ng/mL). The primary outcome was acute kidney injury defined as meeting Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) Injury or Failure criteria. Logistic regression examined the RIFLE criteria outcome. Adjusted odds ratios were estimated by multivariate logistic regression models. Preadmission 25-hydroxyvitamin D deficiency is predictive of acute kidney injury. Patients with 25-hydroxyvitamin D deficiency have an odds ratio for acute kidney injury of 1.73 (95% confidence interval 1.30-2.30; p < .0001) relative to patients with 25-hydroxyvitamin D sufficiency. 25-Hydroxyvitamin D deficiency remains a significant predictor of acute kidney injury following multivariable adjustment (adjusted odds ratio 1.50; 95% confidence interval 1.42-2.24; p < .0001). Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for acute kidney injury of 1.49 (95% confidence interval 1.15-1.94; p = .003) and an adjusted odds ratio of 1.23 (95% confidence interval 1.12-1.72; p = .003) relative to patients with 25-hydroxyvitamin D sufficiency. In addition, preadmission 25-hydroxyvitamin D deficiency is predictive of mortality. Patients with 25-hydroxyvitamin D insufficiency have an odds ratio for 30-day mortality of 1.60 (95% confidence interval 1.18-2.17; p = .003) and an adjusted odds ratio of 1.61 (95% confidence interval 1.06-1.57; p = .004) relative to patients with 25-hydroxyvitamin D sufficiency.
  
  
  CONCLUSIONS
  Deficiency of 25-hydroxyvitamin D prior to hospital admission is a significant predictor of acute kidney injury and mortality in a critically ill patient population.
authors.affiliation: Renal Division, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Braun
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Moromizato
authors.forename: Fiona K
authors.initials: FK
authors.lastname: Gibbons
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Christopher
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000401:mortality; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001900:Boston; D016638:Critical Illness; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D036301:Qualitative Research; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000401:mortality
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D