Beneficial effect of increasing water intake on a lithiasic population of Sidi-Bel-Abbes，West Algerian region
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《中华医药杂志》英文版
1 Laboratory of Biotoxicology, Faculty of Sciences, University Djillali Liabes of Sidi-Bel-Abbés，Sidi-Bel-Abbés 22000, Algéria
2 Laboratory of Physiology and Cellular Pharmacology, Faculty of Sciences, University Mohamed 1, Oujda 60000, Morocco
Correspondence to Mrs. Djamila HARRACHE,S2, Hai Madina Mounaouara,Sidi-Bel-Abbés 22000, Algéria
Tel: (213) 48 55 83 72 /(mobile): (213) 76 49 69 99,Fax: (213) 48 54 43 44 or (213) 48 54 06 11
E-mail:dj_chettouh@yahoo.fr or djharrache@yahoo.fr
[Abstract] Objective Increasing in water intake is widely recommended for lithiasic patients to prevent the likelihood of recurrence. This study was carried out to evaluate the beneficial effect of increasing drinking water in a lithiasic patients of Sidi-Bel-Abbes and its impact on crystalluria, urinary pH, and urinary density.Methods The study was undertaken in 29 patients who accepted to increase their water intake during two months. Fresh morning urine samples were collected and analyzed for their crystalluria by light and polarized microscope. Urinary pH and density were also measured.Results Following the increase of water intake, crystalluria was fallen from 88.5% to 53.4%. The main crystals interested by this decrease were widdelite, whewillite, amorphous carbonated calcium phosphate, and amorphous urate complex. However, an increase of crystalluria was observed for brushite, struvite, and uric acid dihydrate. The urinary pH increased 0.308 unit in 36% of lithiasic patients who have had an initial pH below 5.8. However, the pH decreased 0.355 units in 80% subjects who have had a urinary pH above 5.8. The increasing water intake had also a beneficial effect on reducing urinary density and consequently contributed to the decrease of lithogenic risk. Conclusions We conclude that increasing water intake was beneficial to the majority of patients by reduction of crystalluria and urinary density. However, it was not benefit for some crystal pH-dependent species. Mineral composition of water and diet should be taken into consideration.
[Key words] nephrolithiasis; water intake; crystalluria; urinary pH and density
INTRODUCTION
Lithiasis patients who have produced one or more stones are more likely to become recurrent stone formers [1~3]. A stone can form only when urine is supersaturated with respect to its constituents such as calcium oxalate, calcium phosphate, and uric acid. It is then highly recommended to provide an efficient stone preventive procedure to avoid lithogenesis. To reduce the propensity of salts constituents to crystallize in the urine and decrease therefore the likelihood of recurrence, patients with kidney stones, regardless their composition, should take some measures including dietary restrictions and increasing fluid intake. This later procedure leads to increased urinary volume and, in turn, to a decreased concentration of lithogenic factors, presumably decreasing the rate of stone formation. In this regard, it was observed that hydration aiming to increase urinary output greater than 2 liters is efficient to decrease stone formation [4, 5]. Such practice of increasing urinary volume with drinking water to prevent recurrence has been in use since the time of Hippocrate. It was noticed that patients exposed to chronic dehydration caused by hot climate, working or staying in overheated places or hot countries, or performing sport activities at high temperature are under high risk of lithiasis incidence [6~10]. Therefore, the increase of water intake is aimed to decrease oversaturation of urinary salts that are able to crystallize and grow to a sufficient size of a calculi, to modify urinary pH influencing therefore the formation of crystals pH-dependent, and finally to increase urinary flux that maybe useful for small stones to be expelled out urinary tract. The beneficial effect of water intake has been studies in many part of the globe. However, rare studies were performed in North Africa. The current study was undertaken to evaluate the beneficial effect of increasing drinking water in a lithiasic population of Sidi Bel-Abbes (Algerian west) and its impact on crystalluria, pH and density of the urine.
MATERIAL AND METHODS
Patients
Our prospective study was undertaken in 39 lithiasic patients who have had at least one lithiasic episode. Only 29 patients (15 men and 14 women), who accepted to follow our drinking protocol during a period of two months, were considered for the current study. They were informed about the importance of the protocol and recommended to drink 2 to 3 liters during the day along. We insisted particularly on the necessity of drinking water before bedtime and at least once during the night. All patients were kept diet free and drank their regular water regardless of its mineral composition.
Urine Collection and Measures
The first morning urine was collected from all subjects and we gathered 276 samples (127 from males and 149 from females) of which 113 samples (58 from males and 55 from females) have been collected at a rate of 4 withdrawals per patient before drinking cure and 163 (69 from males and 94 from females) have been collected at the rate of 6 per patient after the cure.
All samples were received daily without any preservative at the laboratory, kept at room temperature, and examined during the 2 hours following the collection. In first instance, urinary pH was measured by a pH meter 0.2 unit and urinary density was measured by weighing urine and water at equal volume by a precision balance. Thus, the urine was homogenized and a sample was drawn close to the bottom of the tube by a Pasteur pipette. The sample was then deposited on a Malassez cell for crystal examination by light and polarized microscope. Crystalluria is considered positive if any crystal is detected in the grid of the cell.
RESULTS AND DISCUSSION
Effect of Water Intake on the Frequency of Crystalluria
The examination of crystalluria in urine samples before water intake revealed that 88.5% of samples were positive. After increasing water intake, only 53.4% of samples were positive.
Crystalluria is considered as a good indicator to be used in the preventive of stone recurrence for lithiasic patients [11]. Numerous studies conducted in large series shown that lithiasic patients have high frequency of positive crystalluria when compared to healthy subjects [12~14]. Considering this point into consideration, some studies suggested that the disappearance of crystalluria or at least its reduction constitutes a therapeutical way to prevent lithiasis recurrence [4, 5]. Indeed, increasing urinary volume contributes to dissolution of soluble complexes of lithogenous salts and lowering, therefore, urinary supersaturation, a pre-requisite of nucleation and growth of a stone. However, it is important to point out that dilution of urine is simultaneously accompanied by a decrease of concentration of urinary inhibitors such as citrate, magnesium, and macromolecules [15].
Effect of Water Intake on the Frequency and Nature of Main Crystals
Following the water intake, a slight modification of frequency of certain type of crystals was observed (Figure 1). In this regard, weddillite which was the main crystal type in 37% of crystalluria fallen significantly to 29% of samples during diuresis cure. A slight decrease, but not significant, was observed for whewillite, amorphous carbonated calcium phosphate (ACCP), and amorphous urate complex (AUC). However, an increase of crystalluria was observed in the case of brushite, struvite, and uric acid dihydrate. The increase of frequency of these type of crystalluria, even after the dilution of urine following an increase of water intake, is due to the fact that the apparition or disappearance of crystal species does not depend solely on the dilution factor but to others including the pH, diet, and the presence of ureasic germs. In fact, in the case of uric acid dihydrate, the pH decreased in 3/5 cases after diuresis, especially in female lithiasic subjects. In case of struvite, it was observed in patients who have had an infected urine after increasing water intake (see section below).
Figure 1 Frequency of main crystals found in the urine of lithiasic patients before and during increasing water intake
Figure 2 Variations of urinary pH of lithiasic patients before and during increasing water intake
Effect of Water Intake on the Urinary pH
Globally, the pH of fresh morning urine decreased during increasing water consumption. This diminution was observed in 65.5% of lithiasic patients (Figure 2 ). The urinary pH changed independently to the initial values of pH for each subject. Indeed, the pH increased 0.308 unit in 36% of lithiasic patients who have had an initial pH below 5.8. However, the pH decreased 0.355 units in 80% subjects who have had a urinary pH above 5.8. These results are in accordance with those found by Garcia Matilla,et al. [16] who showed that urinary pH increased 0.57 units over the baseline. There was an increase of urinary pH following water diuresis when initial pH was below 5.8 and, in contrary, there was a decrease of urinary pH when initial pH was over 5.8. Such results were not observed in a study conducted in Algerian population of Mostaganem [17]. Indeed, they found an increase of urinary pH when initial pH was below 6.5 and no significant variation was observed when initial pH was over 6.5. The variation of pH that we found in our patients has a beneficial effect on crystal pH-dependent species. Consequently, the increase of urinary pH contributes to dissolution of uric acid dihydrate, urate and contributes, also, to dissolution of amorphous carbonated calcium phosphate that are involved in heterogeneous nucleation.
Effect of Water Intake on Urinary Density
Following water diuresis, urinary density decreased in 83% samples of lithiasic patients (Figure 3). The variation of density in relation to crystalluria showed that increasing water intake decreased to half of samples presenting crystalluria with a density comprised between 1.012 and 1.014. Moreover, 34% of samples with a density below 1.008 showed no crystalluria after increasing water intake. However, there was no significant diminution of crystalluria in samples with a density above 1.015 ( Figure 4).
Figure 3 Variations of urinary density of lithiasic patients before and during increasing water intake
Figure 4 Relationship between frequency of crystalluria and specific gravity of lithiasic patients before and during increasing water intake
Correlation between Water Intake and Crystallogenesis Risk
This part of the study has been undertaken in 18 lithiasic patients (8 men and 10 women) of the same lithiasics group, who volunteered to follow the diuresis protocol. We studied the correlation between 24 hours urinary volume and the volume of water consumed, the relationship between 24 hours urinary volume and related density, and finally, the link between urinary density of first morning urine and 24 hours urine. We noticed that, before starting the diuresis cure, the medium urinary volume of our patients was 705 ml/day. This volume appeared to be very weak and comparable to the one obtained by others [4]. Thus, our patients are under the risk of lithogenesis since their urine were not sufficiently diluted and consequently lithogenous substances may precipitate and form stones.The medium density measured in samples of first morning urine of patients was 1.008. However, the medium density measured in 24 hours urine samples was 1.021. Such value is greater than 1.015 fixed as the limit of lithogenous risk [18,19]. After, starting the cure protocol, patients increased their drinking water to 1 940 ml/day which increased their urinary volume to 1 281 ml/day. The average density of first morning and 24 hours urine was 0.976 and 1.000 respectively. Thus, even the volume of diuresis remained insufficient, the increasing water intake contributed to reduce urinary density below values of lithogenous risk. Indeed, there was a good correlation between water intake and urinary volume with a correlation coefficient 0.901 (P<0.0001) (Figure 5). The analysis by regression showed a narrow relationship between 24 hours urinary volume and density (r=-0.928, P<0.0001) (Figure 6). More the diuresis of 24 hours urine is important, more the density decreased. In contrary, low diuresis volume contributes to supersaturation and put patients under high risk of lithogenesis. Finally, we found a positive correlation (r=0.784,P< 0.0001) between the density of first morning urine and 24 hours urine (Figure 7). Indeed, the density of 24 hours urine samples was higher than that of first morning urine. However, according to previous studies [19], the density of first morning urine was higher than that of 24 hours urine instead. The only explanation we can advance is our patients increased water intake before bedtime and during the night.
Figure 5 Correlation between water intake and 24h urine volumes of lithiasic patients
Figure 6 Correlation between 24h urine volume and specific gravity of lithiasic patients after increasing water intake
Figure 7 Correlation between specific gravity of first morning and 24h urine samples of lithiasic patients after increasing water intake
CONCLUSION
We conclude that increasing water intake was beneficial in some extent to the majority of patients. Increasing water consumption contributed to reduction of crystalluria and urinary density lowering therefore the lithogenous risk. However, diuresis cure was not beneficial for some crystal pH-dependent species like brushite, struvite, and uric acid dihydrate since the evolution of urinary pH did not progress in the sense of their dissolution. Other factors should be considered and taken into consideration such as diet and mineral composition of water. Globally, the increase of water intake appeared to be beneficial in prevention of crystallization pH-independent.
REFERENCES
1. Williams RE. Long-term survey of 538 patients with upper urinary stone. Brit J Urol,1963, 35: 416-437.
2. Coe FL, Keck J, Norton ER. The natural history of calcium urolithiasis. JAMA, 1977; 238: 1519-1523.
3. Ljunghall S, Danielson BG. A prospective study of renal stone recurrences. Brit J Urol, 1984, 56: 122-124.
4. Borghi L, Meschi T, Amato F, Briganti A, Novarini A, Giannini A. Urinary volume, water and recurrences in idiopathic calcium nephrolithias: A 5 year randomized prospective study. J Urol, 1996,155: 839-843.
5. Pak CYC, Sakhaee K, Crowther C, Brinkley L. Evidence justifying a high fluid intake in treatment of nephrolithiasis. Ann Intern Med, 1980, 93: 36-41.
6. Parry ES, Lister IS. Sunlight and hypercalciuria. Lancet, 1975, 1: 1063-1065.
7. Pierce LW, Bloom B. Observations on urolithiasis among American troops in a desert area. J Urol, 1945, 54: 466-467.
8. Ferrie BG, Scott R. Occupation and urinary tract stone disease. Urology,1984, 24: 443-445.
9. Irving RA, Noakes TD, Rodgers AL, Swartz L. Crystalluria in marathon runners. 1. Standard marathon males. Urol Res, 1986,14: 289-294.
10. Borghi L, Meschi T, Amato F, Novarini A, Romanelli A, Cigala F. Hot occupation and nephrolithiasis. J Urol, 1993, 150: 1757-1760.
11. Jungers P, Daudon M, Conort P. Lithiase rénale, diagnostique et traitement. Paris, Flammarion Médicine-Sciences, 1989，1-34.
12. Bader CA, Chevalier A, Hennequin C, Jungers P, Daudon M. Methodological aspect of spontaneous crystalluria studies in calcium stone formers. Scanning Microsc,1994, 8: 215-232.
13. Hallson PC, Rose GA. Crystalluriain normal subjects and in stone formers with and without thiazide and cellulose phosphate treatment. Br J Urol,1976, 48: 515-524.
14. Werness PG, Bergert JH, Smith LH. Crystalluria. J Crystal Growth,1981, 53: 166-181.
15. Goldfarb S. The role of diet in the pathogenesis and therapy of nephrolithiasis. Endocr Metab Clin N Amer,1990, 19: 805-820.
16. Garcia Matilla F, Garcia Montes F, Ribas Sera J. Relaciones entre diuresis, pH de la orina y litogenesis. Act Urol Esp,1999, 23: 202-213.
17. Kaid-Omar Z, Belouatek A, Driouch A, Taleb-Bendiab H, Lacour B, Addou A, Daudon M. Effets de la cure de diurèse sur lexpulsabilité spontanée des calculs urinaires, le pH urinaire et la cristallurie des patients lithiasiques. Prog Urol, 2001,11: 450-457.
18. Hubert J, Hubert C, Jungers P, Daudon M, Hartemann P. Eaux de boisson et lithiase calcique urinaire idiopathique. Quelles eaux de boisson et quelle cure de diurèse ? Prog Urol, 2002,12: 692-699
19. Hennequin C, Daudon M, Phung T, Lacour B, Jungers P. Evaluation du risque lithogène dans la lithiase rénale: intérêt de la mesure de la densité urinaire. Presse Med,1995, 24: 1559-1562.
(Editor Jaque)(Amar A1, Harrache-Chettou)
2 Laboratory of Physiology and Cellular Pharmacology, Faculty of Sciences, University Mohamed 1, Oujda 60000, Morocco
Correspondence to Mrs. Djamila HARRACHE,S2, Hai Madina Mounaouara,Sidi-Bel-Abbés 22000, Algéria
Tel: (213) 48 55 83 72 /(mobile): (213) 76 49 69 99,Fax: (213) 48 54 43 44 or (213) 48 54 06 11
E-mail:dj_chettouh@yahoo.fr or djharrache@yahoo.fr
[Abstract] Objective Increasing in water intake is widely recommended for lithiasic patients to prevent the likelihood of recurrence. This study was carried out to evaluate the beneficial effect of increasing drinking water in a lithiasic patients of Sidi-Bel-Abbes and its impact on crystalluria, urinary pH, and urinary density.Methods The study was undertaken in 29 patients who accepted to increase their water intake during two months. Fresh morning urine samples were collected and analyzed for their crystalluria by light and polarized microscope. Urinary pH and density were also measured.Results Following the increase of water intake, crystalluria was fallen from 88.5% to 53.4%. The main crystals interested by this decrease were widdelite, whewillite, amorphous carbonated calcium phosphate, and amorphous urate complex. However, an increase of crystalluria was observed for brushite, struvite, and uric acid dihydrate. The urinary pH increased 0.308 unit in 36% of lithiasic patients who have had an initial pH below 5.8. However, the pH decreased 0.355 units in 80% subjects who have had a urinary pH above 5.8. The increasing water intake had also a beneficial effect on reducing urinary density and consequently contributed to the decrease of lithogenic risk. Conclusions We conclude that increasing water intake was beneficial to the majority of patients by reduction of crystalluria and urinary density. However, it was not benefit for some crystal pH-dependent species. Mineral composition of water and diet should be taken into consideration.
[Key words] nephrolithiasis; water intake; crystalluria; urinary pH and density
INTRODUCTION
Lithiasis patients who have produced one or more stones are more likely to become recurrent stone formers [1~3]. A stone can form only when urine is supersaturated with respect to its constituents such as calcium oxalate, calcium phosphate, and uric acid. It is then highly recommended to provide an efficient stone preventive procedure to avoid lithogenesis. To reduce the propensity of salts constituents to crystallize in the urine and decrease therefore the likelihood of recurrence, patients with kidney stones, regardless their composition, should take some measures including dietary restrictions and increasing fluid intake. This later procedure leads to increased urinary volume and, in turn, to a decreased concentration of lithogenic factors, presumably decreasing the rate of stone formation. In this regard, it was observed that hydration aiming to increase urinary output greater than 2 liters is efficient to decrease stone formation [4, 5]. Such practice of increasing urinary volume with drinking water to prevent recurrence has been in use since the time of Hippocrate. It was noticed that patients exposed to chronic dehydration caused by hot climate, working or staying in overheated places or hot countries, or performing sport activities at high temperature are under high risk of lithiasis incidence [6~10]. Therefore, the increase of water intake is aimed to decrease oversaturation of urinary salts that are able to crystallize and grow to a sufficient size of a calculi, to modify urinary pH influencing therefore the formation of crystals pH-dependent, and finally to increase urinary flux that maybe useful for small stones to be expelled out urinary tract. The beneficial effect of water intake has been studies in many part of the globe. However, rare studies were performed in North Africa. The current study was undertaken to evaluate the beneficial effect of increasing drinking water in a lithiasic population of Sidi Bel-Abbes (Algerian west) and its impact on crystalluria, pH and density of the urine.
MATERIAL AND METHODS
Patients
Our prospective study was undertaken in 39 lithiasic patients who have had at least one lithiasic episode. Only 29 patients (15 men and 14 women), who accepted to follow our drinking protocol during a period of two months, were considered for the current study. They were informed about the importance of the protocol and recommended to drink 2 to 3 liters during the day along. We insisted particularly on the necessity of drinking water before bedtime and at least once during the night. All patients were kept diet free and drank their regular water regardless of its mineral composition.
Urine Collection and Measures
The first morning urine was collected from all subjects and we gathered 276 samples (127 from males and 149 from females) of which 113 samples (58 from males and 55 from females) have been collected at a rate of 4 withdrawals per patient before drinking cure and 163 (69 from males and 94 from females) have been collected at the rate of 6 per patient after the cure.
All samples were received daily without any preservative at the laboratory, kept at room temperature, and examined during the 2 hours following the collection. In first instance, urinary pH was measured by a pH meter 0.2 unit and urinary density was measured by weighing urine and water at equal volume by a precision balance. Thus, the urine was homogenized and a sample was drawn close to the bottom of the tube by a Pasteur pipette. The sample was then deposited on a Malassez cell for crystal examination by light and polarized microscope. Crystalluria is considered positive if any crystal is detected in the grid of the cell.
RESULTS AND DISCUSSION
Effect of Water Intake on the Frequency of Crystalluria
The examination of crystalluria in urine samples before water intake revealed that 88.5% of samples were positive. After increasing water intake, only 53.4% of samples were positive.
Crystalluria is considered as a good indicator to be used in the preventive of stone recurrence for lithiasic patients [11]. Numerous studies conducted in large series shown that lithiasic patients have high frequency of positive crystalluria when compared to healthy subjects [12~14]. Considering this point into consideration, some studies suggested that the disappearance of crystalluria or at least its reduction constitutes a therapeutical way to prevent lithiasis recurrence [4, 5]. Indeed, increasing urinary volume contributes to dissolution of soluble complexes of lithogenous salts and lowering, therefore, urinary supersaturation, a pre-requisite of nucleation and growth of a stone. However, it is important to point out that dilution of urine is simultaneously accompanied by a decrease of concentration of urinary inhibitors such as citrate, magnesium, and macromolecules [15].
Effect of Water Intake on the Frequency and Nature of Main Crystals
Following the water intake, a slight modification of frequency of certain type of crystals was observed (Figure 1). In this regard, weddillite which was the main crystal type in 37% of crystalluria fallen significantly to 29% of samples during diuresis cure. A slight decrease, but not significant, was observed for whewillite, amorphous carbonated calcium phosphate (ACCP), and amorphous urate complex (AUC). However, an increase of crystalluria was observed in the case of brushite, struvite, and uric acid dihydrate. The increase of frequency of these type of crystalluria, even after the dilution of urine following an increase of water intake, is due to the fact that the apparition or disappearance of crystal species does not depend solely on the dilution factor but to others including the pH, diet, and the presence of ureasic germs. In fact, in the case of uric acid dihydrate, the pH decreased in 3/5 cases after diuresis, especially in female lithiasic subjects. In case of struvite, it was observed in patients who have had an infected urine after increasing water intake (see section below).
Figure 1 Frequency of main crystals found in the urine of lithiasic patients before and during increasing water intake
Figure 2 Variations of urinary pH of lithiasic patients before and during increasing water intake
Effect of Water Intake on the Urinary pH
Globally, the pH of fresh morning urine decreased during increasing water consumption. This diminution was observed in 65.5% of lithiasic patients (Figure 2 ). The urinary pH changed independently to the initial values of pH for each subject. Indeed, the pH increased 0.308 unit in 36% of lithiasic patients who have had an initial pH below 5.8. However, the pH decreased 0.355 units in 80% subjects who have had a urinary pH above 5.8. These results are in accordance with those found by Garcia Matilla,et al. [16] who showed that urinary pH increased 0.57 units over the baseline. There was an increase of urinary pH following water diuresis when initial pH was below 5.8 and, in contrary, there was a decrease of urinary pH when initial pH was over 5.8. Such results were not observed in a study conducted in Algerian population of Mostaganem [17]. Indeed, they found an increase of urinary pH when initial pH was below 6.5 and no significant variation was observed when initial pH was over 6.5. The variation of pH that we found in our patients has a beneficial effect on crystal pH-dependent species. Consequently, the increase of urinary pH contributes to dissolution of uric acid dihydrate, urate and contributes, also, to dissolution of amorphous carbonated calcium phosphate that are involved in heterogeneous nucleation.
Effect of Water Intake on Urinary Density
Following water diuresis, urinary density decreased in 83% samples of lithiasic patients (Figure 3). The variation of density in relation to crystalluria showed that increasing water intake decreased to half of samples presenting crystalluria with a density comprised between 1.012 and 1.014. Moreover, 34% of samples with a density below 1.008 showed no crystalluria after increasing water intake. However, there was no significant diminution of crystalluria in samples with a density above 1.015 ( Figure 4).
Figure 3 Variations of urinary density of lithiasic patients before and during increasing water intake
Figure 4 Relationship between frequency of crystalluria and specific gravity of lithiasic patients before and during increasing water intake
Correlation between Water Intake and Crystallogenesis Risk
This part of the study has been undertaken in 18 lithiasic patients (8 men and 10 women) of the same lithiasics group, who volunteered to follow the diuresis protocol. We studied the correlation between 24 hours urinary volume and the volume of water consumed, the relationship between 24 hours urinary volume and related density, and finally, the link between urinary density of first morning urine and 24 hours urine. We noticed that, before starting the diuresis cure, the medium urinary volume of our patients was 705 ml/day. This volume appeared to be very weak and comparable to the one obtained by others [4]. Thus, our patients are under the risk of lithogenesis since their urine were not sufficiently diluted and consequently lithogenous substances may precipitate and form stones.The medium density measured in samples of first morning urine of patients was 1.008. However, the medium density measured in 24 hours urine samples was 1.021. Such value is greater than 1.015 fixed as the limit of lithogenous risk [18,19]. After, starting the cure protocol, patients increased their drinking water to 1 940 ml/day which increased their urinary volume to 1 281 ml/day. The average density of first morning and 24 hours urine was 0.976 and 1.000 respectively. Thus, even the volume of diuresis remained insufficient, the increasing water intake contributed to reduce urinary density below values of lithogenous risk. Indeed, there was a good correlation between water intake and urinary volume with a correlation coefficient 0.901 (P<0.0001) (Figure 5). The analysis by regression showed a narrow relationship between 24 hours urinary volume and density (r=-0.928, P<0.0001) (Figure 6). More the diuresis of 24 hours urine is important, more the density decreased. In contrary, low diuresis volume contributes to supersaturation and put patients under high risk of lithogenesis. Finally, we found a positive correlation (r=0.784,P< 0.0001) between the density of first morning urine and 24 hours urine (Figure 7). Indeed, the density of 24 hours urine samples was higher than that of first morning urine. However, according to previous studies [19], the density of first morning urine was higher than that of 24 hours urine instead. The only explanation we can advance is our patients increased water intake before bedtime and during the night.
Figure 5 Correlation between water intake and 24h urine volumes of lithiasic patients
Figure 6 Correlation between 24h urine volume and specific gravity of lithiasic patients after increasing water intake
Figure 7 Correlation between specific gravity of first morning and 24h urine samples of lithiasic patients after increasing water intake
CONCLUSION
We conclude that increasing water intake was beneficial in some extent to the majority of patients. Increasing water consumption contributed to reduction of crystalluria and urinary density lowering therefore the lithogenous risk. However, diuresis cure was not beneficial for some crystal pH-dependent species like brushite, struvite, and uric acid dihydrate since the evolution of urinary pH did not progress in the sense of their dissolution. Other factors should be considered and taken into consideration such as diet and mineral composition of water. Globally, the increase of water intake appeared to be beneficial in prevention of crystallization pH-independent.
REFERENCES
1. Williams RE. Long-term survey of 538 patients with upper urinary stone. Brit J Urol,1963, 35: 416-437.
2. Coe FL, Keck J, Norton ER. The natural history of calcium urolithiasis. JAMA, 1977; 238: 1519-1523.
3. Ljunghall S, Danielson BG. A prospective study of renal stone recurrences. Brit J Urol, 1984, 56: 122-124.
4. Borghi L, Meschi T, Amato F, Briganti A, Novarini A, Giannini A. Urinary volume, water and recurrences in idiopathic calcium nephrolithias: A 5 year randomized prospective study. J Urol, 1996,155: 839-843.
5. Pak CYC, Sakhaee K, Crowther C, Brinkley L. Evidence justifying a high fluid intake in treatment of nephrolithiasis. Ann Intern Med, 1980, 93: 36-41.
6. Parry ES, Lister IS. Sunlight and hypercalciuria. Lancet, 1975, 1: 1063-1065.
7. Pierce LW, Bloom B. Observations on urolithiasis among American troops in a desert area. J Urol, 1945, 54: 466-467.
8. Ferrie BG, Scott R. Occupation and urinary tract stone disease. Urology,1984, 24: 443-445.
9. Irving RA, Noakes TD, Rodgers AL, Swartz L. Crystalluria in marathon runners. 1. Standard marathon males. Urol Res, 1986,14: 289-294.
10. Borghi L, Meschi T, Amato F, Novarini A, Romanelli A, Cigala F. Hot occupation and nephrolithiasis. J Urol, 1993, 150: 1757-1760.
11. Jungers P, Daudon M, Conort P. Lithiase rénale, diagnostique et traitement. Paris, Flammarion Médicine-Sciences, 1989，1-34.
12. Bader CA, Chevalier A, Hennequin C, Jungers P, Daudon M. Methodological aspect of spontaneous crystalluria studies in calcium stone formers. Scanning Microsc,1994, 8: 215-232.
13. Hallson PC, Rose GA. Crystalluriain normal subjects and in stone formers with and without thiazide and cellulose phosphate treatment. Br J Urol,1976, 48: 515-524.
14. Werness PG, Bergert JH, Smith LH. Crystalluria. J Crystal Growth,1981, 53: 166-181.
15. Goldfarb S. The role of diet in the pathogenesis and therapy of nephrolithiasis. Endocr Metab Clin N Amer,1990, 19: 805-820.
16. Garcia Matilla F, Garcia Montes F, Ribas Sera J. Relaciones entre diuresis, pH de la orina y litogenesis. Act Urol Esp,1999, 23: 202-213.
17. Kaid-Omar Z, Belouatek A, Driouch A, Taleb-Bendiab H, Lacour B, Addou A, Daudon M. Effets de la cure de diurèse sur lexpulsabilité spontanée des calculs urinaires, le pH urinaire et la cristallurie des patients lithiasiques. Prog Urol, 2001,11: 450-457.
18. Hubert J, Hubert C, Jungers P, Daudon M, Hartemann P. Eaux de boisson et lithiase calcique urinaire idiopathique. Quelles eaux de boisson et quelle cure de diurèse ? Prog Urol, 2002,12: 692-699
19. Hennequin C, Daudon M, Phung T, Lacour B, Jungers P. Evaluation du risque lithogène dans la lithiase rénale: intérêt de la mesure de la densité urinaire. Presse Med,1995, 24: 1559-1562.
(Editor Jaque)(Amar A1, Harrache-Chettou)