Low Urine pH Research Articles

Low Urine pH Is a Predictor of Chronic Kidney Disease

Background/Aims: A variety of risk factors for chronic kidney disease (CKD), including the metabolic syndrome, were recently reported. It has been suggested that a low urine pH is another characteristic of the metabolic syndrome. However, the relationship between urine pH and CKD remains to be elucidated. Methods: A cohort study was performed on 1,811 subjects who underwent a health check-up, and we examined whether low urine pH could be a predictor of CKD. The following risk factors for CKD were evaluated: age, gender, history of alcohol intake and smoking, BMI, systolic blood pressure, fasting plasma glucose, total cholesterol, uric acid, total leukocyte count, CKD stage, fasting urine pH, and protein at baseline. Results: We followed 1,811 subjects for a median period of 7.7 years. Three hundred and thirty-nine subjects developed stage 3 CKD defined as progression to estimated glomerular filtration rate <60 ml/min/1.73 m². Multiple Cox regression analysis revealed that the adjusted HR (95% CI) for stage 3 CKD was 1.32 (1.06–1.65; p = 0.0129) in subjects with fasting urine pH 5.0–5.5 compared to subjects with pH 6.5–7.0. Conclusion: Our study suggests that low urine pH is an independent predictor of stage 3 CKD.

Overweight, insulin resistance and blood pressure (parameters of the metabolic syndrome) in uric acid urolithiasis

Overweight, arterial hypertension and disturbances of the carbohydrate metabolism are important parameters of the metabolic syndrome (MS). The most important factor regarding renal pathophysiology is insulin resistance resulting in alterations of urine acidification and low urine pH. Since low urine pH is the main risk factor for uric acid urolithiasis (UAU), UAU may be regarded as a renal manifestation of the MS. So far, there are only few data on the prevalence of parameters of the MS in UAU patients especially with regard to the severity of the disease and recurrence rate, respectively. The objective of this study was to know more about the prevalence of different parameters of the MS and their importance for the natural history of this type of renal stone disease using a total number of 167 consecutive patients with pure UA stones. Stone analysis was performed by polarization microscopy and X-ray diffraction. The following parameters were measured: age, sex, systolic and diastolic arterial blood pressure (RRs and RRd), number of stone episodes, diabetes mellitus (DM); serum: creatinine, calcium, sodium, potassium, uric acid, glucose; urine: pH-profiles, citrate, calcium, uric acid, ammonia, urea, and creatinine. The following results were obtained (means ± standard deviations): age 61 ± 13 years, BMI 30 ± 6 kg/m(2), BP 147/84 ± 22/13 mmHg, number of stone episodes 1.8 ± 1.2, DM 32%; serum: creatinine 1.3 ± 0.6 mg/dl, glucose 136 ± 52 mg/dl, UA 6.3 ± 1.8 mg/dl, calcium 2.4 ± 1.3 mmol/l, sodium 134 ± 18 mmol/l, potassium 4.1 ± 0.4 mmol/l; urine: pH 5.87 ± 0.27, volume 2.4 ± 1.1 l/d, calcium 3.5 ± 2.5 mmol/d, UA 3.9 ± 2.4 mmol/d, citrate 1.3 ± 1.1 mmol/d, ammonia 41 ± 26 mmol/d, urea 390 ± 176 mmol/d. A significant positive correlation could be found for BMI and urea excretion, BMI correlated negatively with RRs and RRd. There was no significant correlation between BMI, urine pH, citrate, ammonia and UA in serum and urine. Undue acidity and hyperuricosuria were found in two-thirds of the UAU patients, increased urea excretion and decreased excretion of ammonia in less than 25%, Hyperuricemia in 37%. There was no significant correlation between the number of stone episodes and any other parameter studied. Overweight, arterial hypertension and DM as parameters of the MS are frequent in many patients with UAU. However, these parameters do explain the pathogenesis in two-thirds of the patients. The severity of the disease and the recurrence are not influenced by the presence of these metabolic parameters. Therefore, MS is no prognostic factor in UAU.

High serum uric acid level and low urine pH as predictors of metabolic syndrome: a retrospective cohort study in a Japanese urban population

The objective of this study was to evaluate whether hyperuricemia, acidic urine, or their combination predicts metabolic syndrome (MetS). In study 1, 69 094 subjects who received a general health checkup between 1985 and 2005 were included in a cross-sectional study of serum uric acid (SUA) and urine pH in relation to MetS. In study 2, the association of SUA and urine pH with MetS development over a 5-year period was evaluated in 5617 subjects with body mass index less than 25 kg/m 2 at the first examination. In study 1, higher SUA and lower urine pH were both positively correlated to MetS status ( P < .001). The combination of high SUA and low urine pH was significantly associated with higher MetS prevalence compared with the combination of low SUA and high urine pH (odds ratio, 3.383; 95% confidence interval [CI], 3.034-3.784 in men; odds ratio, 4.000; 95% CI, 2.992-5.452 in women). In study 2, the top quartile of SUA levels was associated with higher MetS development compared with the bottom quartile during the 5-year period in men (hazard ratio [HR], 1.793; 95% CI, 1.084-2.966; P = .023). In women, the HR was 3.732 (95% CI, 0.391-35.62; P = .252) for the upper vs the lower half of SUA levels. For urine pH, the HR was 1.955 (95% CI, 1.089-3.509; P = .025) for the bottom vs the top quartile in men. A likelihood ratio test confirmed that high SUA and low urine pH act synergistically in the development of MetS. High SUA, low urine pH, and their combination are predictive risk factors for MetS development.

Uric Acid Nephrolithiasis: A Systemic Metabolic Disorder.

Uric acid nephrolithiasis is characteristically a manifestation of a systemic metabolic disorder. It has a prevalence of about 10% among all stone formers, the third most common type of kidney stone in the industrialized world. Uric acid stones form primarily due to an unduly acid urine; less deciding factors are hyperuricosuria and a low urine volume. The vast majority of uric acid stone formers have the metabolic syndrome, and not infrequently, clinical gout is present as well. A universal finding is a low baseline urine pH plus insufficient production of urinary ammonium buffer. Persons with gastrointestinal disorders, in particular chronic diarrhea or ostomies, and patients with malignancies with a large tumor mass and high cell turnover comprise a less common but nevertheless important subset. Pure uric acid stones are radiolucent but well visualized on renal ultrasound. A 24 h urine collection for stone risk analysis provides essential insight into the pathophysiology of stone formation and may guide therapy. Management includes a liberal fluid intake and dietary modification. Potassium citrate to alkalinize the urine to a goal pH between 6 and 6.5 is essential, as undissociated uric acid deprotonates into its much more soluble urate form.

Influence of Obesity on Urinary pH With Respect to Sex in Healthy Koreans

To evaluate the association between urinary pH and metabolic risk factors, including obesity according to sex in a Korean population recruited through the health promotion center. From 2008 to 2010, a total of 22 297 ostensibly healthy adult Koreans who visited our health promotion center were enrolled in the present study. The relationship between urinary pH and various metabolic risk factors, including obesity, were evaluated. The mean age ± SD of the study population was 45.0 ± 9.1 years. The men had a significantly greater body mass index and lower urinary pH than the women. Using multivariate logistic regression analysis, obesity significantly correlated with a lower urinary pH (≤5.5) only in men (odds ratio [OR] 1.095, P = .015) and not in women (OR 1.004, P = 0.945). Among the various factors examined, older age (>45 years), greater fasting blood glucose, and hyperuricemia were factors significantly associated with a lower urinary pH in both groups. Hypertriglyceridemia was a significant factor associated with lower urinary pH only in men, and a lower high-density lipoprotein cholesterol was the significant factor for a lower urinary pH in women. The results of the present study revealed that obesity is significantly correlated with lower urinary pH (≤5.5) only in men.

Effect of Renal Function on Urinary Mineral Excretion and Stone Composition

To determine the effect of renal function on urinary mineral stone excretion and composition of kidney stones in patients undergoing urologic intervention for nephrolithiasis. We performed a retrospective analysis of 158 patients with 193 kidney stones who underwent endourologic intervention for nephrolithiasis. The patients were grouped by the estimated glomerular filtration rate (eGFR). The kidney stone composition and results of the 24-hour urinalysis were reported for each group. Statistical analysis was performed using the chi-square test, Kruskal-Wallis test, and analysis of variance. The kidney stone composition profile differed significantly between the groups, with uric acid stones associated with a lower eGFR and calcium phosphate stones associated with a greater eGFR. A lower eGFR correlated with lower urine pH, lower calcium excretion, and greater oxalate excretion. Excretion of uric acid and the body mass index did not differ between groups. Different degrees of renal function correlated with certain types of kidney stones. The urine pH was lower in patients with impaired renal function. Renal function might be an underappreciated factor that affects kidney stone composition and urinary mineral excretion.

Produção leiteira, composição do leite e perfil bioquímico sanguíneo de vacas lactantes sob suplementação com sal aniônico

Objetivou-se avaliar os efeitos da inclusão de sal aniônico na dieta sobre as características físicas e a composição química do leite, o perfil bioquímico sanguíneo, a produção de leite, o peso e a condição corporal de vacas em lactação. Foram utilizadas 20 vacas da raça Jersey distribuídas em duas dietas, uma sem adição de sal aniônico e outra com adição de 0,25 kg/dia de cloreto de amônio. O delineamento empregado foi o completamente casualizado. As vacas sob suplementação com sal aniônico apresentaram menor pH urinário e aumento das concentrações sanguíneas de ureia, cálcio e magnésio. Com a dieta aniônica, o leite precipitou com menores concentrações de etanol, apresentou menor densidade, porcentagens de lactose, proteína e imunoglobulina, porém maior teor de cálcio iônico. O fornecimento de dieta aniônica durante a lactação resultou em acidose metabólica, o que alterou o perfil bioquímico sanguíneo e as características físico-químicas do leite.

2054 EFFECT OF GLOMERULAR FILTRATION RATE ON 24-HOUR URINE ANALYSIS

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112054 EFFECT OF GLOMERULAR FILTRATION RATE ON 24-HOUR URINE ANALYSIS Adam Kadlec, Kristin Greco, Zach Fridirici, Daniel Gerber, and Thomas Turk Adam KadlecAdam Kadlec Maywood, IL More articles by this author , Kristin GrecoKristin Greco Maywood, IL More articles by this author , Zach FridiriciZach Fridirici Maywood, IL More articles by this author , Daniel GerberDaniel Gerber Hamilton, NY More articles by this author , and Thomas TurkThomas Turk Maywood, IL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2285AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We tested the hypothesis that 24-hour urine analyses collected from patients with low glomerular filtration rates (GFR <60) would differ from normal counterparts. METHODS We used the Modification of Diet in Renal Disease (MDRD) equation to calculate GFR in 146 patients who gave a 24-hour urine analysis after undergoing urologic surgery for kidney stones. Patients were grouped by GFR with a cutpoint of 60 ml/hr. A two-sample t-test was used to calculate p-values. RESULTS Patients with GFR <60 had less urinary calcium excretion and a lower urinary pH. They also excreted more oxalate and sodium. Other commonly measured parameters did not significantly differ between groups. Supersaturation indices (SSI) did not differ between groups. CONCLUSIONS The levels of clinically relevant urinary minerals vary depending on GFR. Patients with impaired GFR have lower urine pH than normal counterparts. Table 1. Urinary excretion of certain lithogenic minerals is dependent on GFR status GFR <60 GFR ≥60 p-value Calcium (mg/day) 149±108 213±167 0.033 Oxalate (mg/day) 40±20 33±15 0.022 Uric Acid (mg/day) 485±237 558±216 0.089 Citrate (mg/day) 433±352 511±343 0.242 Urine pH 5.79±0.63 6.13±0.59 0.005 Volume (L/day) 1.94±0.69 1.86±0.74 0.559 Sodium (meq/day) 194±86 157±75 0.013 Sulfate (mmol/day) 17±10 16±8 0.675 Phosphorus (mg/day) 960±405 889±331 0.298 Magnesium (mg/day) 84±42 100±115 0.430 Table 2. Supersaturation Indices (SSI) Did Not Differ Between Groups SSI GFR <60 GFR >60 p-value Calcium Oxalate 1.40±1.13 1.79±1.12 0.073 Brushite 1.86±5.44 1.73±1.36 0.825 Monosodium Urate 2.05±1.95 2.60±2.26 0.194 Struvite 0.30±0.56 2.93±5.95 0.142 Uric Acid 1.68±1.26 2.21±7.70 0.684 © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e822 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Adam Kadlec Maywood, IL More articles by this author Kristin Greco Maywood, IL More articles by this author Zach Fridirici Maywood, IL More articles by this author Daniel Gerber Hamilton, NY More articles by this author Thomas Turk Maywood, IL More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

2149 WEIGHT LOSS INTERVENTION REDUCES THE RISK OF KIDNEY STONE FORMATION IN A RAT MODEL OF METABOLIC SYNDROME

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112149 WEIGHT LOSS INTERVENTION REDUCES THE RISK OF KIDNEY STONE FORMATION IN A RAT MODEL OF METABOLIC SYNDROME Yumiko Sasaki, Yasuo Kohjimoto, Akinori Iba, Nagahide Matsumura, and Takeshi Inagaki Yumiko SasakiYumiko Sasaki Wakayama City, Japan More articles by this author , Yasuo KohjimotoYasuo Kohjimoto Wakayama City, Japan More articles by this author , Akinori IbaAkinori Iba Wakayama City, Japan More articles by this author , Nagahide MatsumuraNagahide Matsumura Wakayama City, Japan More articles by this author , and Takeshi InagakiTakeshi Inagaki Wakayama City, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2360AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We have previously reported that metabolic syndrome (MetS) increases the risk of kidney stone formation through low urinary pH, decreased citrate excretion, and increased uric acid and calcium excretion, and that the improving insulin resistance by pioglitazone reversed low urinary pH (BJU Int 106: 1550–1554, 2010). However, it has not been studied whether weight loss intervention reduces the risk of kidney stone formation. The present study examined the effect of diet restriction and/or exercise on the urinary stone risk parameters in a rat model of MetS. METHODS Four-week-old male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of MetS, were randomly assigned to 3 groups of 6 rats each. Control rats were sedentary with free access to standardized diet. Food restricted (FR) rats were sedentary with 30% reduction of daily food ingestion compared to the control rats. Exercise-trained (ET) rats were provided voluntary access to running wheels in combination with 30% food restriction. All rats were allowed free access to drinking water. After 16 weeks blood and 24-hour urine samples were collected. RESULTS FR rats and ET rats showed significantly lower body weight, serum triglyceride, cholesterol, glucose, insulin, homeostasis model assessment ratio (HOMA-R) compared to control rats. In these weight intervention groups, urinary pH and citrate excretion were significantly higher and ion-activity product of calcium oxalate [AP (CaOx)] index, an indicator of CaOx crystal formation, was significantly lower than those of control rats (p<0.01, Figure). Other urinary parameters were not significantly different among the groups. When 24-week-old male OLETF, that had already developed type 2 diabetes, were submitted to the same protocol, similar results were obtained. CONCLUSIONS The results indicate that weight loss intervention reduces the risk of uric acid stone formation by improving low urine pH and CaOx stone formation by increasing urinary citrate excretion. The present study provides the first theoretical evidence to recommend weight loss intervention program for nephorolithiasis patients with MetS. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e860-e861 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yumiko Sasaki Wakayama City, Japan More articles by this author Yasuo Kohjimoto Wakayama City, Japan More articles by this author Akinori Iba Wakayama City, Japan More articles by this author Nagahide Matsumura Wakayama City, Japan More articles by this author Takeshi Inagaki Wakayama City, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows

Feeding rations with low dietary cation-anion difference (DCAD) to dairy cows during late gestation is a common strategy to prevent periparturient hypocalcemia. Although the efficacy of low-DCAD rations in reducing the incidence of clinical hypocalcemia is well documented, potentially deleterious effects have not been explored in detail. The objective of the study presented here was to determine the effect of fully compensated metabolic acidosis on calcium and phosphorus homeostasis, insulin responsiveness, and insulin sensitivity as well as on protein metabolism. Twenty multiparous Holstein-Friesian dairy cows were assigned to 1 of 2 treatment groups and fed a low-DCAD ration (DCAD = −9 mEq/100g, group L) or a control ration (DCAD = +11 mEq/100g, group C) for the last 3 wk before the expected calving date. Blood and urine samples were obtained periodically between 14 d before to 14 d after calving. Intravenous glucose tolerance tests and 24-h volumetric urine collection were conducted before calving as well as 7 and 14 d postpartum. Cows fed the low-DCAD ration had lower urine pH and higher net acid excretion, but unchanged blood pH and bicarbonate concentration before calving. Protein-corrected plasma Ca concentration 1 d postpartum was higher in cows on the low-DCAD diet when compared with control animals. Urinary Ca and P excretion was positively associated with urine net acid excretion and negatively associated with urine pH. Whereas metabolic acidosis resulted in a 6-fold increase in urinary Ca excretion, the effect on renal P excretion was negligible. A more pronounced decline of plasma protein and globulin concentration in the periparturient period was observed in cows on the low-DCAD diets resulting in significantly lower total protein and globulin concentrations after calving in cows on low-DCAD diets. Intravenous glucose tolerance tests conducted before and after calving did not reveal group differences in insulin response or insulin sensitivity. Our results indicate that fully compensated metabolic acidosis increased the Ca flux resulting in increased urinary calcium excretion before calving and increased plasma Ca concentration on the day after calving, whereas the effect on P homeostasis was unlikely to be clinically relevant. The clinical relevance of the effect of metabolic acidosis on the plasma protein and globulin concentration is unclear but warrants further investigation.

Association of urine acidification with visceral obesity and the metabolic syndrome

Urine acidification is induced by metabolic acidosis which is associated with a high intake of protein-rich diet. The purpose of this study was to investigate the relationship of urine acidification with visceral obesity and the metabolic syndrome. We recruited 1,051 male subjects who underwent health examinations at the Health Care Center in Kinki Central Hospital. Subjects who were treated for hypertension, dyslipidemia, diabetes mellitus, and hyperuricemia and had the past history of chronic liver disease, chronic kidney disease and cancer, were excluded in this study. All subjects were administered to urine pH, blood and physical examinations. Lower urine pH was associated with higher serum urea nitrogen which reflects high intake of protein-rich diet, whereas it had no relation to serum creatinine. Lower urine pH was also associated with an increase in waist circumference, homeostasis model assessment-R, fasting plasma glucose, HbA1c, serum triglyceride, serum uric acid and with a decrease in high density lipoprotein cholesterol. Urine pH was not associated with mean blood pressure. Urine acidification is a characteristic of visceral obesity and the metabolic syndrome. High intake of protein-rich diet may contribute urine acidification, which is associated with various metabolic abnormalities in visceral obesity.

Urethral obstruction in cats: predisposing factors, clinical, clinicopathological characteristics and prognosis

Feline lower urinary tract diseases in general, and urethral obstruction (UO) in particular, are common clinical conditions in cats. The aims of this study were to identify risk factors for UO, to characterise clinical and clinicopathological signs, outcome and recurrence, as well as risk factors for mortality and recurrence. Eighty-two cats with UO were compared to 82 sex and time matched controls. The mean age of cats with UO was significantly lower compared to controls, while the mean body weight was higher. The proportion of indoors-outdoors cats was significantly lower in the study group compared to the control group, and the proportion of cats consuming only dry food was higher. Overall mortality was 8.5%. Ionised calcium was significantly higher in survivors compared to non-survivors, and the prevalence of hypocalcaemia was lower. Recurrence in 6 months and 2 years were 22% and 24%, respectively. Cats with recurrence had significantly lower urine pH at presentation.

Pendrin Modulates ENaC Function by Changing Luminal HCO3 −

The epithelial Na(+) channel, ENaC, and the Cl(-)/HCO(3)(-) exchanger, pendrin, mediate NaCl absorption within the cortical collecting duct and the connecting tubule. Although pendrin and ENaC localize to different cell types, ENaC subunit abundance and activity are lower in aldosterone-treated pendrin-null mice relative to wild-type mice. Because pendrin mediates HCO(3)(-) secretion, we asked if increasing distal delivery of HCO(3)(-) through a pendrin-independent mechanism "rescues" ENaC function in pendrin-null mice. We gave aldosterone and NaHCO(3) to increase pendrin-dependent HCO(3)(-) secretion within the connecting tubule and cortical collecting duct, or gave aldosterone and NaHCO(3) plus acetazolamide to increase luminal HCO(3)(-) concentration, [HCO(3)(-)], independent of pendrin. Following treatment with aldosterone and NaHCO(3), pendrin-null mice had lower urinary pH and [HCO(3)(-)] as well as lower renal ENaC abundance and function than wild-type mice. With the addition of acetazolamide, however, acid-base balance as well as ENaC subunit abundance and function was similar in pendrin-null and wild-type mice. We explored whether [HCO(3)(-)] directly alters ENaC abundance and function in cultured mouse principal cells (mpkCCD). Amiloride-sensitive current and ENaC abundance rose with increased [HCO(3)(-)] on the apical or the basolateral side, independent of the substituting anion. However, ENaC was more sensitive to changes in [HCO(3)(-)] on the basolateral side of the monolayer. Moreover, increasing [HCO(3)(-)] on the apical and basolateral side of Xenopus kidney cells increased both ENaC channel density and channel activity. We conclude that pendrin modulates ENaC abundance and function, at least in part by increasing luminal [HCO(3)(-)] and/or pH.

Plaque and deposits in nine human stone diseases

Data concerning nine forms of human stone disease, along with observations on normal people give new insights into formation of interstitial apatite plaque and intra-tubular crystal deposits. In general, across multiple disease states, one can reproduce the same relationships between plaque abundance as is seen among patients within individual disease states, so that the link between plaque and high urine calcium excretion, and low urine volume and pH seems increasingly secure. From this, one can propose a specific model of plaque formation, susceptible to experimental test. In many diseases, formation of inner medullary collecting duct and Bellini duct deposits is compatible with simple crystallization driven by urine supersaturations; this is expected in that these segments contain tubule fluid quite close in composition to final urine. But in ileostomy, small bowel disease and obesity bypass patients, crystals found in deposits are not those expected: apatite and urates in deposits, despite formation of highly acidic urine. Also, this discrepancy suggests the possibility of divergence between bulk urine pH and pH of focal collecting ducts, a new kind of possibility that is susceptible to experimental test.

Cola beverage and delayed elimination of methotrexate

To report a case of severe delayed methotrexate elimination attributable to consumption of a cola beverage. To investigate unexplained low urinary pH in a lymphoma patient treated with high-dose methotrexate. Unexpected urinary acidity, despite administration of large amounts of sodium bicarbonate, could be attributed to repeated consumption of a cola beverage. It resulted in a delayed elimination of methotrexate and acute renal failure. Discontinuation of cola drinks, increase in calcium folinate rescue and in sodium bicarbonate allowed satisfactory elimination of methotrexate on day 12 after infusion and recovery from renal impairment without other severe toxicity. No other cause of delay in methotrexate elimination could be identified. Cola beverages have a low pH due to their phosphoric acid content that is excreted by renal route. We recommend patients receiving high dose methotrexate abstain from any cola drink within 24 h before and during methotrexate administration and until complete elimination of the drug.

Combining gastric and ileal segments, does it overcome segment-related complications? An experimental study on rats

Bladder augmentation has revolutionized the care of children with neurogenic bladder but it is associated with certain short- and long-term complications. Using the combination of gastric and ileal segments to balance effects of these segments might be a solution for complications. A total of 39 female Spraque-Dawley rats randomly divided into four groups: ileocystoplasty (11), gastrocystoplasty (9), ileogastrocystoplasty (11) and control (8). Serum/urine electrolytes and pH values, and serum creatinine levels and urine mucus concentration were measured. Kruskal-Wallis non-parametric variance analysis was performed to compare the groups and p < 0.05 was accepted as significant. Metabolic alkalosis with significantly lower urine pH was observed in gastrocystoplasty group. Gastroileal group showed similar results with the ileal group in all parameters. No stone formation was detected in the sham and gastric cystoplasty groups. Metaplastic and hyperplastic changes were observed in all segments surrounding urothelium. In conclusion, combination of gastric and ileal segments does not significantly reduce the rate of metabolic impairments, stone and mucus formation. Besides it is not associated with significant improvement in histological outcome since urine is still in contact with the gastrointestinal mucosa.

Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study

BackgroundThe acid-ash hypothesis, the alkaline diet, and related products are marketed to the general public. Websites, lay literature, and direct mail marketing encourage people to measure their urine pH to assess their health status and their risk of osteoporosis.The objectives of this study were to determine whether 1) low urine pH, or 2) acid excretion in urine [sulfate + chloride + 1.8x phosphate + organic acids] minus [sodium + potassium + 2x calcium + 2x magnesium mEq] in fasting morning urine predict: a) fragility fractures; and b) five-year change of bone mineral density (BMD) in adults.MethodsDesign: Cohort study: the prospective population-based Canadian Multicentre Osteoporosis Study. Multiple logistic regression was used to examine associations between acid excretion (urine pH and urine acid excretion) in fasting morning with the incidence of fractures (6804 person years). Multiple linear regression was used to examine associations between acid excretion with changes in BMD over 5-years at three sites: lumbar spine, femoral neck, and total hip (n = 651). Potential confounders controlled included: age, gender, family history of osteoporosis, physical activity, smoking, calcium intake, vitamin D status, estrogen status, medications, renal function, urine creatinine, body mass index, and change of body mass index.ResultsThere were no associations between either urine pH or acid excretion and either the incidence of fractures or change of BMD after adjustment for confounders.ConclusionUrine pH and urine acid excretion do not predict osteoporosis risk.

Metabolic Basis for Low Urine pH in Type 2 Diabetes

Type 2 diabetes is associated with excessively low urine pH, which increases the risk for uric acid nephrolithiasis. This study was conducted to assess the metabolic basis responsible for the excessive urinary acidity of individuals with type 2 diabetes. Nine non-stone-forming patients who had type 2 diabetes and low urine pH and 16 age- and body mass index-matched non-stone-forming volunteers without type 2 diabetes were maintained on a constant metabolic diet for 7 days, and 24-hour urine was collected on the last 2 days of the diet. Urine dietary markers (potassium, sulfate, phosphorus, and urea nitrogen) were not different between the two groups. Patients with type 2 diabetes exhibited a significantly lower 24-hour urine pH (5.45+/-0.27 versus 5.90+/-0.42; P<0.01) and higher net acid excretion (NAE; 57+/-12 versus 38+/-18 mEq/d; P<0.01) compared with control subjects. The proportion of NAE excreted as ammonium (NH4+/NAE) was significantly lower in patients with type 2 diabetes than in control subjects (0.70+/-0.12 versus 0.94+/-0.36; P<0.01); however, the greater NAE in patients with type 2 diabetes was not accounted for by the differences in unmeasured urinary anions. The overly acidic urine in patients with type 2 diabetes persists after controlling for dietary factors, body size, and age. The lower pH is due to a combination of greater NAE and lower use of ammonia buffers in patients with diabetes, which predisposes them to uric acid urolithiasis.

Anionic salts in the prepartum diet and addition of sodium bicarbonate to colostrum replacer, and their effects on immunoglobulin G absorption in the neonate

The objectives of this experiment were to determine whether feeding anionic salts to prepartum Holstein cows affected their calf's colostral IgG passive transfer and whether adding sodium bicarbonate to a colostrum replacer (CR) would increase the efficiency of IgG absorption. Forty Holstein cows and their resulting calves were assigned to a 2 × 2 factorial arrangement of treatments in a randomized complete block design based on expected date of calving. Three weeks before the projected due date, cows were placed on 1 of 2 treatments: a diet without anionic salts (dietary cation-anion difference of +77 mEq/kg) or a diet with anionic salts (dietary cation-anion difference of −100 mEq/kg). Within 45min after birth, all calves received 1 dose of a commercially available CR (132g of IgG) without or with supplemental sodium bicarbonate (19.5 g/dose). A half-dose of CR (66g of IgG) and sodium bicarbonate (9.75g) was fed at 6h of age. Calves received milk replacer at 12, 24, 36, and 48h. Blood samples were obtained from calves at 0, 6, 12, 24, and 48h and were analyzed for IgG concentration. Cows fed the diet supplemented with anionic salts had lower DMI on d 8, 5, 4, and 1 and lower urine pH 2 and 1 wk before parturition compared with cows fed the diet without supplemental anionic salts. Calves born from dams receiving anionic salts had similar IgG concentrations (15.1 vs. 14.4g/L) and apparent efficiency of absorption values (29.2 vs. 28.2%) compared with calves born from dams not fed anionic salts. Calves receiving supplemental sodium bicarbonate in the CR had higher serum IgG concentrations at 12 (14.4 vs. 12.0g/L), 24 (16.3 vs. 13.2g/L), and 48h (14.6 vs. 11.2g/L) and higher apparent efficiency of absorption values (31.2 vs. 26.1%) than calves that did not receive sodium bicarbonate in the CR. Calves receiving sodium bicarbonate also had greater area under the curve values for IgG absorption compared with calves not receiving sodium bicarbonate. There was a trend for an interaction with calves born from dams fed anionic salts having a greater area under the curve when fed supplemental sodium bicarbonate. Of the 40 calves in the study, 90% obtained adequate passive transfer (serum IgG ≥10g/L). This study indicates that feeding anionic salts to the dam has no effect on passive transfer, whereas adding sodium bicarbonate to the CR increased IgG uptake in calves.

Diabetic Kidney Stone Formers Excrete More Oxalate and Have Lower Urine pH Than Nondiabetic Stone Formers

The epidemiological relationship between nephrolithiasis and type 2 diabetes mellitus is well-known. Patients with diabetes mellitus are at increased risk for nephrolithiasis and those with nephrolithiasis are at risk for diabetes mellitus. We examined 24-hour urine composition in stone formers with and without diabetes mellitus. We retrospectively reviewed a database of 462 stone forming patients to examine the relationship between hypertension and 24-hour urine composition. Multivariate linear regression models were adjusted for age, race, gender, body mass index, hypertension, relevant medications and 24-hour urine constituents. On univariate analysis diabetic patients had significantly greater urine volume than nondiabetic patients (2.5 vs 2.1 l daily, p = 0.004). Those with diabetes mellitus also excreted less daily potassium (61.1 vs 68.8 mEq, p = 0.04), phosphate (0.84 vs 1.0 gm, p = 0.002) and creatinine (1405.5 vs 1562.8 mg, p = 0.03), and had significantly lower daily urine pH (5.78 vs 6.09, p <0.001) and CaP supersaturation (0.49 vs 1.20, p <0.001) than nondiabetic patients. On multivariate analysis compared to patients without diabetes mellitus those with type II diabetes mellitus had significantly lower urine pH (-0.34, 95% CI -0.48 to -0.21) and significantly greater urine oxalate (6.43 mg daily, 95% CI 1.26 to 11.60) and volume (0.38 l daily, 95% CI 0.13 to 0.64). Results show that of stone formers patients with type II diabetes mellitus excrete significantly greater urinary oxalate and significantly lower urine pH than those without diabetes mellitus. These findings are important for treating nephrolithiasis since they may influence dietary counseling, medical management and stone prevention.