Daily oral sodium bicarbonate preserves glomerular filtration rate by slowing its decline in early hypertensive nephropathy

Kidney Int. 2010 Aug;78(3):303-9. doi: 10.1038/ki.2010.129. Epub 2010 May 5.

Abstract

In most patients with hypertensive nephropathy and low glomerular filtration rate (GFR), the kidney function progressively declines despite the adequate control of the hypertension with angiotensin-converting enzyme inhibition. Previously we found that 2 years of oral sodium citrate slowed GFR decline in patients whose estimated GFR (eGFR) was very low (mean 33 ml/min). This treatment also slowed GFR decline in an animal model of surgically reduced nephron mass. Here, we tested if daily oral sodium bicarbonate slowed GFR decline in patients with hypertensive nephropathy with reduced but relatively preserved eGFR (mean 75 ml/min) in a 5-year, prospective, randomized, placebo-controlled, and blinded interventional study. Patients matched for age, ethnicity, albuminuria, and eGFR received daily placebo or equimolar sodium chloride or bicarbonate while maintaining antihypertensive regimens (including angiotensin-converting enzyme inhibition) aiming for their recommended blood pressure targets. After 5 years, the rate of eGFR decline, estimated using plasma cystatin C, was slower and eGFR was higher in patients given sodium bicarbonate than in those given placebo or sodium chloride. Thus, our study shows that in hypertensive nephropathy, daily sodium bicarbonate is an effective kidney protective adjunct to blood pressure control along with angiotensin-converting enzyme inhibition.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Albuminuria / drug therapy
  • Albuminuria / physiopathology
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology
  • Angiotensin-Converting Enzyme Inhibitors / therapeutic use
  • Antihypertensive Agents / pharmacology
  • Antihypertensive Agents / therapeutic use
  • Blood Pressure / drug effects
  • Cystatin C / blood
  • Double-Blind Method
  • Drug Therapy, Combination
  • Female
  • Glomerular Filtration Rate / drug effects*
  • Humans
  • Hypertension / complications*
  • Hypertension / drug therapy
  • Hypertension / physiopathology
  • Kidney / drug effects
  • Kidney / physiopathology
  • Kidney Diseases / drug therapy*
  • Kidney Diseases / etiology*
  • Kidney Diseases / physiopathology
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prospective Studies
  • Sodium Bicarbonate / administration & dosage
  • Sodium Bicarbonate / pharmacology*

Substances

  • Angiotensin-Converting Enzyme Inhibitors
  • Antihypertensive Agents
  • Cystatin C
  • Sodium Bicarbonate