EFFECT OF WATER AND BICARBONATE LOADING IN PATIENTS WITH CHRONIC-RENAL-FAILURE

Animal studies suggest that alkalinization and increased intake of fre e water both serve to decrease the rate of progression in chronic rena l failure. However, clinicians have been reluctant to apply either str ategy because of concerns regarding volume overload and water intoxica tion. We tested the effects of 21 daily water supplementation, with ei ther an electrolyte-poor or a HCO3-rich (47.5 mmol/l) water in 11 pati ents with chronic renal failure (creatinine clearance 10 +/- 5 ml/min) . The patients were brought into balance on a diet containing 80 mmol/ 24 h Na+, 80 mmol/24 h Cl- and 70 mmol/24 h K+. After a 3-day equilibr ation period, the patients were randomized to one or the other regimen for 7 days. After a 3-day washout period, the alternate regimen was g iven for another 7 days, Neither regimen led to weight gain or hyponat remia. The supplemental 95 mmol/24 h HCO3- lowered the serum Cl- conce ntration and raised the serum HCO3- concentration, as well as the pH v alue, to normal. Creatinine clearance and protein excretion were not a ffected. Serum beta(2)-microglobulin concentrations decreased with the NaHCO3-containing water. Na+/H+-antiporter activity was not consisten tly influenced since an order effect of the regimens was apparent. We conclude that 21/24 h water and NaHCO3 supplementation is well tolerat ed, causes no deleterious effects, and may evoke improvement in patien ts with chronic renal failure.