title: Increasing water intake by 2 liters reduces crystallization risk indexes in healthy subjects.
abstract: OBJECTIVE
  The objective of the present study was to evaluate the effects of drinking 2 additional litres of water/day on several urinary risk factors for lithiasis in healthy subjects, through measurement of crystallization risk indices (Tiselius CRI).
  
  
  METHODS
  48 healthy subjects, aged 25 to 50 were studied for urinary parameters including CRI in the laboratory ward, for 24 hours. After this first period, they were randomized either to a 2L/d additional water intake (treated group) or usual fluid consumption (control group) for a 6 days period, which ended by a second measurement period in the laboratory ward for 24 hours.
  
  
  RESULTS
  Total additional water intake was actually 1.3L/d on average in treated subjects, because subjects decreased other usual sources of fluid intake. In 24 hour urine, Tiselius CRI varied differently among treated subjects and controls between the 2 periods; male controls subjects experienced much higher values (above 2 in average in first morning urine sample) in the second period (p = 0.05). Of interest, in a transversal analysis, we observed a positive relation between BMI or waist circumference on the one hand, and with 24 hour urea excretion or osmotic load on the other hand.
  
  
  CONCLUSIONS
  These results show a beneficial effect of a final 1.3L additional water intake on Tiselius CRI in healthy subjects.
authors.affiliation: Danone Research, Palaiseau, France. viviane.de-la-gueronniere@danone.com
authors.forename: Viviane
authors.initials: V
authors.lastname: de La Guéronnière
authors.forename: Laurent
authors.initials: L
authors.lastname: Le Bellego
authors.forename: Inmaculada Buendia
authors.initials: IB
authors.lastname: Jimenez
authors.forename: Oriane
authors.initials: O
authors.lastname: Dohein
authors.forename: Ivan
authors.initials: I
authors.lastname: Tack
authors.forename: Michel
authors.initials: M
authors.lastname: Daudon
mesh_terms: D000328:Adult; D003460:Crystallization; D004326:Drinking; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D052878:Urolithiasis / Q000517:prevention & control*