Background and Objectives: Urinary stones are common throughout the world, usually caused by supersaturated urine. The quantity of water intake and its mineral and trace elements have been reported to influence the urolithiasis. This study was carried out to compare the effects of Tehran tap water (TTW, with a low degree of hardness) and Damavand Ala-Spring Mineral Water (DMW, with a high degree of hardnes) on urinary mineral elements in men with and without kidney calcium stones at Hasheminejad Hospital, Tehran.
Materials and Methods:This single-blind clinical trial included 29 15-62-year old male subjects, 14 with, and 15 without urinary stones, hospitalized in Hasheminejad Hospital, Tehran. The patients without urinary stones did not suffer from renal disorders or urinary stones, but had been hospitalized for rupture. None of the subjects was taking citrate, vitamin D, vitamin C, or Ca supplements, and showed no symptoms of pyuria or hematuria. Based on ideal weights of the subjects, their diets were prepared,weighed, packed and offered to them. Morning and 24-hour urine samples were collected before and after the intervention for oxalate, citrate, phosphate, uric acid, creatinine, Mg, Ca, specific gravity, and pH determinations. All the subjects were offered distilled water, 30-36 ml/kg/day, for 2 days (days 1 and 2), followed by the. same volume of TTW for 2 days (days 3 and 4) and, finally the same volume of DMW for the last 2 days (days 5 and 6). Data were analyzed using SPSS11.5, the statistical tests being ANOVA (repeated measures) and t-test.
Results: The age, weight, height, and BMI of the 2 groups of men showed no statistically significant differences. The urine volume increased significantly after taking distilled water and TTW (P<0.01) and mineral water (P<0.05). Distilled water and TTW reduced the urine specific gravity significantly (P<0.05). The specific gravity after consumption of TTW and DMW was lower after distilled water (P<0.01). Calcium levels after intake of distilled water and TTW were significantly different between the two groups (P<0.05). The data also showed that, as compared to distilled water, TTW increases urinary citrate, magnesium, phosphate, and the urine volume in men with nephrolithiasis and DMW increases urinary magnesium, phosphate and pH in men without nephrolithiasis however, the differences were not significantly different.
Conculsions: Results of this study showed that increasing water intake increases urinary volume and decreases specific gravity, irrespective of the degree of water hardness. Consumption of TTW is more beneficial (and may potentially prevent recurrence of stone formation) than that of the harder mineral water for patients with urinary stones, while consumption of the latter may be more beneficial for people without urinary stones. People should drink more water in order to reduce stone formation.
Zare M, Aminpour A, Mirzazadeh M, Azar M, Tazakori Z, Mehrabi Y et al . Comparison of the effects of two types of drinking water with different degrees of hardness on urinary mineral elements in men with and without kidney calcium stones . Iranian J Nutr Sci Food Technol 2007; 1 (3) :1-7 URL: http://nsft.sbmu.ac.ir/article-1-20-en.html