Double-blind, randomised study of the effect of combined treatment with vitamin C and E on albuminuria in Type 2 diabetic patients

Diabet Med. 2001 Sep;18(9):756-60. doi: 10.1046/j.0742-3071.2001.00574.x.

Abstract

Aims: Elevated levels of urinary albumin excretion rate (AER) predict high risk for progressing to end-stage renal disease. In streptozotocin-induced diabetes, supplementation with vitamin C or E reduces albuminuria and glomerular hypertrophy. We tested the hypothesis that supplementation of both vitamin C and E in pharmacological doses lowers AER in Type 2 diabetic patients with persistent micro/macroalbuminuria.

Methods: Thirty Type 2 diabetic patients with AER 30-300 mg/24 h were included in a double-blind randomised, cross-over trial. Patients received vitamin C (1250 mg) and vitamin E (680 IU) per day or matching placebo for 4 weeks with a 3-week wash-out period between treatment periods in random order.

Results: Combined treatment with vitamin C and E reduced AER by 19% (95% CI 6-34%) (p = 0.04), geometric mean 197 mg/24 h (95% CI 114-341 mg/24 h) vs. 243 mg/24 h (146-404 mg/24 h). No changes were seen in serum creatinine, haemoglobin A1C or blood pressure. Fasting plasma concentrations of vitamin C and E increased in all patients during active treatment (mean vitamin C 79.4 micromol/L (SD 27.8) vs. 41.9 micromol/L (18.4) and vitamin E 47.0 micromol/L (19.8) vs. 29.5 micromol/L (15.3), P < 0.000001). Except for two patients that started additional blood pressure lowering treatment during the run-in period, no changes in medication, food and exercise habits or in the number of smokers occurred during the study.

Conclusion: Short-term treatment with vitamin C and E in pharmacological doses lowers AER in Type 2 diabetic patients with micro/macroalbuminuria. Further long-term, large-scale studies of this albuminuria reducing treatment modality are warranted.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Albuminuria / drug therapy*
  • Ascorbic Acid / administration & dosage
  • Ascorbic Acid / blood
  • Ascorbic Acid / therapeutic use*
  • Cross-Over Studies
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Double-Blind Method
  • Drug Therapy, Combination
  • Fasting
  • Female
  • Glycated Hemoglobin A / analysis
  • Humans
  • Male
  • Middle Aged
  • Placebos
  • Vitamin E / administration & dosage
  • Vitamin E / blood
  • Vitamin E / therapeutic use*
  • alpha-Tocopherol / administration & dosage
  • alpha-Tocopherol / blood
  • alpha-Tocopherol / therapeutic use*

Substances

  • Glycated Hemoglobin A
  • Placebos
  • Vitamin E
  • alpha-Tocopherol
  • Ascorbic Acid