title: Plasma vitamin C concentrations in patients on routine hemodialysis and its relationship to patients' morbidity and mortality.
abstract: BACKGROUND
  Some studies have hypothesized the protective role of vitamin C against cardiovascular disorders (CVD) in patients with end-stage renal disease (ESRD). This study was designed to assess plasma vitamin C concentration and its relationship to hemodialysis (HD) patients' morbidity and mortality.
  
  
  METHODS
  Plasma vitamin C concentrations were assessed in HD patients using spectrophotometry and subjects were prospectively followed for up eighteen months for all-cause mortality. Any association between vitamin C concentration and patients' demographic data, co-morbidities, or the cause of ESRD were investigated using the Chi-square test.
  
  
  RESULTS
  Ninety-one patients with a mean age of 56.7 ± 15.7 years were included in this study. The most frequent cause of ESRD was simultaneous hypertension and diabetes in 30 % of patients, followed by hypertension in 25.6 %, and diabetes in 11.1 %, respectively. About 34 % of patients had CVD as the most prevalent co-morbidity. Forty-nine patients (53.8 %) had low levels of vitamin C concentration. There was a significant relationship between vitamin C insufficiency and presence of any co-morbidity in HD patients (p < 0.05). There was a significant difference in vitamin C concentrations between patients without co-morbidities and those with cardiovascular ones (F[2,88]=3.447, p = 0.036). Twenty-two (24.2 %) patients died over a median duration of 227 days. There was a significant difference in time to death of patients with and without low levels of vitamin C concentration (p = 0.04).
  
  
  CONCLUSIONS
  The results showed lower plasma vitamin C levels in HD patients who suffered any co-morbidity and sooner time to death in these patients.
authors.affiliation: Nephrology Research Center and Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. dashtis@sina.tums.ac.ir
authors.forename: Simin
authors.initials: S
authors.lastname: Dashti-Khavidaki
authors.forename: Azita Hajhossein
authors.initials: AH
authors.lastname: Talasaz
authors.forename: Hamed
authors.initials: H
authors.lastname: Tabeefar
authors.forename: Mannan
authors.initials: M
authors.lastname: Hajimahmoodi
authors.forename: Ghazaleh
authors.initials: G
authors.lastname: Moghaddam
authors.forename: Hossein
authors.initials: H
authors.lastname: Khalili
authors.forename: Mahboob
authors.initials: M
authors.lastname: Lessan-Pezeshki
authors.forename: Afsaneh
authors.initials: A
authors.lastname: Jahanmardi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001205:Ascorbic Acid / Q000097:blood*; D001206:Ascorbic Acid Deficiency / Q000453:epidemiology / Q000209:etiology; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003928:Diabetic Nephropathies / Q000097:blood / Q000453:epidemiology / Q000209:etiology / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006785:Hospitals, University; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D007492:Iran / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009026:Mortality; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D001205:Ascorbic Acid