title: [Effects of water diuresis on the urinary ph of patients under relapsing lithiasis].
abstract: BACKGROUND
  It has been observed that in healthy individuals the increase in urinary flow induced by water overload may be enough to alter the urinary Ph to obtain values considered safe in the prophylaxis of lithogenesis. The aim of the present paper is to determine the effects of water diuresis on the urinary Ph of patients suffering from relapsing lithiasis.
  
  
  METHODS
  26 patients were included in the present study. The urinary Ph of all patients was measured along two consecutive days, at 8.30 and again at 12.30, under normal conditions (the first day) and once they had received a water load equivalent to 1.5% of their weight (the second day).
  
  
  RESULTS
  The altered mean value of the Ph induced on the first day by the circadian rhythm showed a mean of 0.13 units of Ph, which lacks statistical significance (p > 0.05). However, on the second day we obtained a value of 0.42, which is statistically significant (p < 0.01). The normal tendency after the water overload was towards a positive increase of the Ph in those patients whose urine showed a preload Ph value < 6.1, whereas those individuals with a preload Ph value > 6.48 suffered negative increases.
  
  
  CONCLUSIONS
  The increase of diuresis induced by water load proved enough to provoke an increase of urinary Ph when its baseline value is < 6.1, or either a decrease when its baseline value is > 6.48. In both cases, Ph values ranged between 6-6.5 which are considered safe values in the prophylaxis of lithogenesis. The more separated the baseline urinary Ph is from the 6.1-6.48 range, the greater the effect of the water load.
authors.affiliation: Servicio de Urología, H.U. Virgen del Rocío, Sevilla.
authors.forename: R A
authors.initials: RA
authors.lastname: Medina López
authors.forename: J
authors.initials: J
authors.lastname: Ribas Serna
authors.forename: F
authors.initials: F
authors.lastname: García Matilla
mesh_terms: D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D004231:Diuresis / Q000502:physiology*; D004326:Drinking / Q000502:physiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D014545:Urinary Calculi / Q000503:physiopathology*; D014556:Urine / Q000502:physiology*; D014867:Water / Q000008:administration & dosage* / Q000502:physiology
chemical_list: D014867:Water