Institut BMK

1. Effect of a bicabonate-rich mineral water in patients with recurrent renal stone formation – a controlled double-blind study Chr. Gutenbrunner, U. Smorag, O. Karagülle, F. Candir, H. Becker, U. Jonas Professor Christoph Gutenbrunner, MD, PhD, Clinic for Physical Medicine and Rehabilitation Hanover Medical School Carl-Neuberg-Str. 1 D-30625 Hannover gutenbrunner.christoph@mh-hannover.de Institut BMK

2. Introduction  In the industrialised countries urolithiasis is a frequent disease  Prevalence in Germany: 4.7%  Incidence: 1.47%  The rate of relapses is high: 50-60%  The extra-corporal shock-wave therapy is not free of complications  For that reason an effective metaphylaxis is of major importance Institut BMK

3. Introduction  A basic principle of the metaphylaxis of urolitioasis is the dilution of the urine by an increase of the fluid intake  Additional principles are  the reduction of the excretion of stone forming substances in the urine: calcium, oxalate, uric acid and others  the enhancement of the excretion of inhibitors: magnesium, citrate and others  the reduction of the crystallisation risk by influencing the pH of the urine (dependent on the type of renal stones) Institut BMK

4. Introduction  From experimental studies it is known that  bicarbonate waters increase the urinary pH and the citrate excretion  magnesium-rich waters increase the urinary excretion of magnesium  the increase of calcium-excretion is over- compensated by the increase of diuresis  Only a few studies were performed in patients  Most studies dealt with the problem of calcium-waters  Therefore we studied the effect of a magnesium- and bicarbonate-rich mineral water Institut BMK

5. Material and Methods Design of the Study: - double-blind controlled study - cross-over-design  Patients: - Patients with multi-episodic CaOx-urolithiasis (n=34) - males/females: 30/4 - number of stone episodes: 3.0 ± 1.6  Setting: - Everyday activities - no standardisation of the diet - nutrition protocol Institut BMK

6. Material and Methods  Interventions: - 1.5 l/d bicarbonated water (2,673 mg HCO3-/l; 175 mg Mg++/l; 116 mg Ca++/l) - 1.5 l/d low-mineralized water (98 mg HCO3-/l 8 mg Mg++/l; 38 mg Ca++/l) - 1.400 ml of each water for three consecutive days - all waters in the same type of bottles, colour code - distance between drinking periods: one week  Main Outcome Parameters: - 24-h-urine samples before drinking, 3rd day of drinking - urinary pH (24-h-urine) - magnesium- and citrate-excretion - supersaturation CaOx and of other types of urinary stones Institut BMK

7. Results Institut BMK

8. Results Institut BMK

9. Results Institut BMK

10. Patients with high risk Institut BMK p1 = Significance between verum and controls p2 = Significance between baseline and drinking period

11. Conclusion  Both waters significantly reduce the renal stone formation risk in patients with relapsing CaOx-urolithiasis  The mineral water additionally increases the urinary pH as well as the excretion of magnesium and citrate  The mineral water is effective even in cases with high risk of stone formation (hypercalciuria, hyperoxaluria)  Bicarbonated waters should be used in patients with combined stones containing CaOx and uric acid or in uric acid stones but not in in patients with phosphate stones Institut BMK