title: High homocysteine, low vitamin B-6, and increased oxidative stress are independently associated with the risk of chronic kidney disease.
abstract: OBJECTIVE
  Hyperhomocysteinemia, increased oxidative stress, and decreased antioxidant defense function have been found to be associated with the risk of chronic kidney disease (CKD). Deficiencies of folate and vitamin B-6 (pyridoxal 5'-phosphate, PLP) may cause hyperhomocysteinemia and increased oxidative stress. The purpose of this study was to determine the associations among homocysteine, folate, PLP, oxidative stress indicator, and antioxidant capacities in patients with stage 2 to 3 CKD, and to further analyze these relationships with respect to risk for CKD.
  
  
  METHODS
  Ninety-seven patients with CKD and 135 healthy subjects were recruited.
  
  
  RESULTS
  Patients with CKD had significantly higher levels of malondialdehyde and total antioxidant capacities, but had significantly lower antioxidant enzyme activities compared with healthy subjects. Serum folate but not plasma PLP was significantly negatively associated with plasma homocysteine. There were no significant associations of homocysteine, PLP, and folate with oxidative stress indicator and antioxidant capacities. High homocysteine (odds ratio [OR] = 1.11; 95% confidence interval [CI], 1.02-1.22) and malondialdehyde (OR = 34.24; 95% CI, 4.44-264.40) level increased the risk of CKD, whereas high plasma PLP (OR = 0.98; 95% CI, 0.97-0.99) and superoxide dismutase activity (OR = 0.82; 95% CI, 0.74-0.91) decreased the risk of CKD after adjusting all potential confounders.
  
  
  CONCLUSIONS
  High homocysteine, low PLP, increased oxidative stress, and decreased antioxidant enzyme activity (superoxide dismutase activity) were independent contributing factors in the development of early stage CKD.
authors.affiliation: Division of Nephrology, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Internal Medicine, Chiayi Branch, Taichung Veterans General Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan; Department of Life Science, Tunghai University, Taichung, Taiwan.
authors.forename: Cheng-Hsu
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Food and Nutrition, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Wen-Ching
authors.initials: WC
authors.lastname: Yang
authors.affiliation: School of Nutrition, Chung Shan Medical University, Taichung, Taiwan; Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Hsiao
authors.affiliation: School of Nutrition, Chung Shan Medical University, Taichung, Taiwan; Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan.
authors.forename: Shih-Chien
authors.initials: SC
authors.lastname: Huang
authors.affiliation: School of Nutrition, Chung Shan Medical University, Taichung, Taiwan; Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan. Electronic address: ych@csmu.edu.tw.
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D005494:Folic Acid Deficiency / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress; D011732:Pyridoxal Phosphate / Q000097:blood* / Q000172:deficiency; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000150:complications; D012307:Risk Factors; D013482:Superoxide Dismutase / Q000097:blood; D025101:Vitamin B 6 / Q000097:blood; D026681:Vitamin B 6 Deficiency / Q000097:blood*
chemical_list: D000975:Antioxidants; D006710:Homocysteine; D008315:Malondialdehyde; D011732:Pyridoxal Phosphate; D025101:Vitamin B 6; D013482:Superoxide Dismutase
keywords: Antioxidant enzyme activities; Chronic kidney disease; Folate; Homocysteine; Oxidative stress; Vitamin B-6