Low Urine Volume Research Articles

Risk factors for low urinary citrate in calcium nephrolithiasis: low vegetable fibre intake and low urine volume to be added to the list.

Risk factors for low urinary citrate excretion were assessed in 34 consecutive male recurrent idiopathic calcium stone formers (RCSF) who collected two 24-h urines while on free-choice diet. Overt hypocitraturia (hypo-cit) was defined as UCit x V < 1.70 mmol/day, and 'low' citraturia (low-cit) as UCit x V between 1.70 and 2.11 mmol/day. Twenty-three RCSF had normocitraturia (normo-cit), six low-cit and five hypo-cit. UCit x V positively correlated with urine volume (VOLUME, r = 0.44, P = 0.009), vegetable fibre intake (fibers, r = 0.46, P = 0.009) and GI-alkali absorption (alkali, r = 0.47, P = 0.006), and volume, fibres and alkali tended to be lower among RCSF with low-/hypo-cit. A 3-day NH4Cl loading test (0.95 mEq/kg BW daily in 3 doses) was performed in RCSF as well as in 14 age-matched healthy male controls (C). On a plot of urine pH versus serum bicarbonate, 10 of 11 RCSF with low-/hypo-cit, but only six of 23 with normo-cit (P = 0.0004) fell off the normal range, indicating incomplete RTA. Two or more risk factors simultaneously occurred in only four of 23 RCSF with normo-cit, but in eight of 11 with low-/hypo-cit (P = 0.002). In conclusion, incomplete RTA is the most prevalent risk factor for low-/hypo-cit in RCSF, and decreases in vegetable fibres and urine volume emerge as two new risk factors for low urinary CIT.

Alterations in Renal Stone Risk Factors after Space Flight

Exposure to the microgravity environment of space produces a number of physiological changes of metabolic and environmental origin that could increase the potential for renal stone formation. Metabolic, environmental and physicochemical factors that influence renal stone risk potential were examined in 24-hour urine samples from astronauts 10 days before launch and on landing day to provide an immediate postflight assessment of these factors. In addition, comparisons were made between male and female crewmembers, and between crewmembers on missions of less than 6 days and those on 6 to 10-day missions. Results suggest that immediately after space flight the risk of calcium oxalate and uric acid stone formation is increased as a result of metabolic (hypercalciuria, hypocitraturia, pH) and environmental (lower urine volume) derangements, some of which could reflect residual effects of having been exposed to microgravity.

The use of cotton balls to collect infant urine samples for 2H/ 1H and 18O/ 16O isotope ratio measurements

To test the validity of cotton balls as a urine collection medium for hydrogen and oxygen isotope ratio measurements, we moistened cotton balls with 1-, 5-, and 10-mL aliquots of urine that contained either natural abundances or one of two enriched levels of 2H and 18O. The liquids were then expressed from the cotton balls, either at once, or after 30 or 60 min of atmospheric exposure, and analyzed for their 2H/ 1H and 18O/ 16O isotope ratios. The 2H abundances of the fluids expressed from the cotton balls were significantly lower than the original values. This dilution of 2H, however, diminished in the samples that had a greater volume of urine. We observed no effects of volume or time on 18O. Our results indicate that at low urine volumes, ambient moisture dilutes 2H in the cotton balls, but isotope exchanges and evaporation have little or no effect on the hydrogen and oxygen isotopic abundances of the urine samples. Total body water and energy expenditure values calculated from the 2H and 18O enrichments of 5- and 10-mL urine samples were within 1% of the theoretical values. Therefore, cotton balls are suitable for collection of infant urine samples for hydrogen and oxygen isotope ratio measurements, if the volume of urine that can be expressed from a cotton ball is ⩾ 5 mL.

Idiopathic Calcium Oxalate Lithiasis in a Recurrent Stone—Forming Patient

Low urinary volume, coupled with hypercalciuria, hyperuricosuria, and high urinary sodium, increases the risk of calcium oxalate lithiasis. Complex interrelationships exist between dietary factors that influence urinary solute excretion. A standard yet individualized nutrition protocol has been developed for treatment of kidney stones that includes normalization of protein and calcium intake, avoidance of oxalate and purine excess, moderation of sodium intake, and generous fluid intake to attain and maintain a urine volume more than 2 L/d. A dietary approach appears safe and logical in decreasing urinary risk factors, but it has not been proven effective in the prevention of recurrent idiopathic calcium lithiasis.

Home parenteral nutrition--a 3-year analysis of clinical and laboratory monitoring.

We report a 3-year analysis (1986 to 1989) of the management of 63 home parenteral nutrition patients, 40 with short-bowel syndrome and 23 with chronic intestinal obstruction with or without intestinal resection. Intravenous fluid requirements varied from 0.9 to 6 L/day, and the content of glucose varied between 46 and 531 g/day, protein varied from .0 to 85 g/day, fat from .0 to 100 g/day, sodium from 37 to 695 mEq/day, potassium from 30 to 220 mEq/day, chloride from 60 to 760 mEq/day, and acetate from 0 to 200 mEq/day. Body weight was normalized and well maintained in the majority of patients, but using the strict definition of deficiency as the presence of one abnormal value during 3 years, more than half had abnormal plasma chloride, glucose, alkaline phosphatase, serum glutamic oxaloacetic transaminase, total protein, albumin, selenium, and iron concentrations, and more than a third had low calcium, magnesium, vitamin D, and vitamin C levels. Normochromic anemia was seen in 73% and high blood creatinine associated with low urine volumes in 42%. Most (78%) returned to relatively normal lifestyles, but employability was occasionally impaired by loss of third-party insurance coverage resulting from a therapy that may cost $100,000 per year. Overall mortality was low (5% per year), but 73% needed readmission to hospital, mainly for suspected catheter sepsis. The results indicate that home parenteral nutrition has allowed many patients to survive gut failure and return to work but problems with chronic fluid, electrolyte and micronutrient deficiencies, catheter sepsis, and insurance coverage often restrict optimal rehabilitation.

Subchronic toxicity study of Caramel Colour II in F344 rats

Caramel Colour II is a distinct type of colourant with a pronounced reddish hue. It is made with sulphite reactants but without ammonia. The red colour and a high alcohol solubility provide functional characteristics that are important in foods or beverages containing natural flavour extractives. Caramel Colour II is widely used in ice creams and liqueurs; however, it represents less than 1% of total caramel colour manufacture. The toxicity of Caramel Colour II was evaluated in a 13-wk study in Fischer-344 (F344) rats. The test material was mixed with demineralized water and the solutions were given to the animals ad lib. in the drinking fluid. The concentrations of caramel colour in the drinking fluid were adjusted periodically to achieve the desired caramel colour intake/kg body weight/day. Groups of 20 rats/sex were given Caramel Colour II at levels of 0, 4, 8, 12 or 16 g/kg for at least 13 wk. There were no deaths in any of the groups fed Caramel Colour II. All rats fed caramel colour had soft faeces. All treated groups also had lower fluid consumption that was attributed to poor palatability of the high concentrations of caramel colour that were fed. A number of changes observed (reduced food consumption in all treatment groups except males given 4 g/kg; significantly lower body weights for males given 12 g/kg or more and for females given 8 g/kg or more; lower urine volume and higher specific gravity) were attributed to the reduced water intake and not considered to be toxicologically significant. There were no consistent treatment-related alterations in haematology or blood chemistry variables, and random changes noted were not associated with macroscopic or microscopic pathological alterations. There were no toxicologically important pathological findings. Based on this study, Caramel Colour II was not toxic in F344 rats treated for 13 wk. The highest dose level tested in this study (16 g/kg) was considered to be the no-observed-adverse-effect level.

Pathogenesis of nephrolithiasis post-partial ileal bypass surgery: Case-control study

Between 1975 and 1983, 838 patients were randomized into the Program on the Surgical Control of Hyperlipidemias (POSCH) trial: 417 to standard medical care and 421 to partial ileal bypass (PIB) surgery. During the course of the trial, an increased incidence of kidney stone formation was found in the surgery group (4%/year) as compared to the control group (0.4%/year). A matched triplet case-control study was conducted to assess the possible causes for the increased incidence of kidney stones. Three groups were studied: PIB stone-formers (S); PIB non-stone formers (N); and non-PIB, non-stone formers in the control group (C). Initially, 162 patients (54 triplets) were selected. Ten percent of the patients declined to participate which resulted in a sample size of 146 patients. The PIB patients had statistically significant (P less than 0.05) lower levels of serum vitamin D metabolites; lower urine volume, pH, citrate, magnesium, carbon dioxide, and sulfate, and higher urinary oxalate, ammonia and relative supersaturation for calcium oxalate and uric acid than the control patients. Although S and N had similar results, those S with no prior history of stones had a higher calcium oxalate supersaturation than similar N with a negative prior history of stones (P less than 0.025). Based on these results, all PIB patients appear to be at risk for kidney stone formation. The combination of reduced urinary volume and calcium oxalate precipitation inhibitor substance with increased calcium oxalate relative supersaturation produced an increase in nephrolithiasis risk in the PIB groups.

Urolithiasis in Tennessee: an occupational window into a regional problem.

Urinary tract stones (stones) are believed to be unusually common in the southeastern United States but neither the incidence of nor the risk factors for stones are known. In three well-defined occupational populations in eastern Tennessee, we assessed the prevalence, incidence, and cumulative incidence of stones and measured biochemical risk factors for lithogenesis. The age-adjusted prevalence of stones was 18.5 percent in Tennessee compared to 7.7 percent among White males in US NHANES (prevalence ratio 2.4, 95% CI 1.7, 3.3). The cumulative incidence (risk) was 27.8 percent by age 65, higher than in any other reported population. Risk factors were age, a family history, and urinary saturation with calcium-oxalate (COAX). Persons with a positive family history and the highest measured CAOX index had a predicted lifetime risk of 88.8 percent. Biochemical factors affecting lithogenesis were hypercalciuria, hyperoxaluria, and low urine volume. Future research should characterize the geographic boundaries of a southeastern "stone-belt" and explore genetic and dietary hypotheses that might explain it.

Less frequent lithium administration and lower urine volume

This study was designed to determine whether patients maintained on a regimen of lithium on a once-per-day schedule have lower urine volumes than do patients receiving multiple doses per day. This was a cross-sectional study of 85 patients from a lithium clinic who received different dose schedules. Patients were admitted to the hospital for measurement of lithium level, creatinine clearance, urine volume, and maximum osmolality. Multiple daily doses of lithium were associated with higher urine volumes. The dosing schedule, duration of lithium treatment, and daily dose of lithium did not affect maximum osmolality or creatinine clearance. Urine volume can be reduced by giving lithium once daily and/or by lowering the total daily dose. Lithium-induced polyuria seems to be related to extrarenal as well as to renal effects.

Neural Stimulation for Control of Voiding Dysfunction: A Preliminary Report in 22 Patients with Serious Neuropathic Voiding Disorders

Our experience with electrode implantation has demonstrated that the most successful combination to achieve continence and promote bladder evacuation is implantation on the ventral component of S3 or S4 and extensive dorsal rhizotomy with selective peripheral neurotomy. Of 22 patients with serious neuropathic voiding disorders treated during the last 6 years results were available for evaluation in 19 (2 were lost to followup and 1 was withdrawn from the protocol because of an infection at the receiver site).In 8 patients (42 per cent) complete success was achieved. These patients have regained reservoir function, are completely dry and void with electrical stimulation. The voiding is synchronous, with low voiding pressure and low residual urine volumes. Ten patients qualify as having partial success. They have regained reservoir function and are dry. One patient voids partially with stimulation, 5 depend on intermittent self-catheterization, 1 regained reservoir function and received an artificial sphincter, and 3 are catheter-dependent (these 3 all had been incontinent preoperatively despite continuous catheter drainage). The remaining patient entered the program long after a cerebrovascular accident and treatment has failed owing to poor selection.The stimulation parameters, once stabilized, did not need to be increased, and neither the surgical manipulation of the sacral roots nor the electrode implantation resulted in further neural loss in any patient.

Prevention of renal stones by a high fluid intake?

From the physiochemical view on the formation of urolithiasis a high fluid intake, provided it resulted in a high urine volume, should reduce the propensity of crystallization, crystal growth and stone formation. This critical review of the literature, however, demonstrates that there is little epidemiologic support for the hypothesis that a low urine volume is an important risk factor for renal stones in temperate climates. Few clinical studies have attempted to elucidate if a large diuresis can prevent further stone formation in a recurrent renal stone former. In the present study 115 recurrent stone formers were followed for an average period of 6 years without any other treatment than advice about a high fluid intake. The annual recurrence rate was around 23% but there was no difference between those who maintained a high urine volume and those who did not. Thus, the available evidence does not indicate that variations of fluid intake markedly affect stone formation.

Pathophysiology of Stone Formation

Urinary stone disease is a multifactorial disorder arising essentially from an abnormal combination of a number of urinary risk factors. In the case of calcium urolithiasis the main risk factors are a low urine volume, a high urinary pH, increased excretions of calcium, oxalate and uric acid and a low net level of inhibitory activity against the crystallization of calcium salts. The last mentioned, in turn, is dependent on the balance between the macromolecular inhibitors, including glycosaminoglycans, ribonucleic acid and acidic glycoproteins, and the promoters of crystallization such as Tamm-Horsfall mucoprotein. There is currently some debate as to whether or not an immunological factor might also be involved in the renal tubules, which results in crystals becoming bound to the renal epithelium.

Pharmacologic Treatment of Uric Acid Calculi

Uric acid stone disease is dependent on three pathogenetic factors: acid urine pH, low urine volume, and hyperuricosuria. The management of nonobstructing uric acid calculi should include maintenance of an alkaline urine, an increase in urine volume, and reduction in urinary uric acid excretion. It appears that potassium alkali may avoid the complication of calcium stone formation in patients with uric acid stones. In patients with obstructing uric acid calculi, more rapid dissolution may be accomplished with intravenous alkalinization or direct irrigation of the stone with an alkaline solution.

Ethanol in cardiomyopathic hamsters: Na and water excretion and righting response

This study examined the effects of ethanol and hereditary cardiomyopathy on sodium and water excretion by golden Syrian hamsters of both sexes. Ethanol (4 g/kg) or the isotonic saline vehicle were injected IP into 60–70-day-old hamsters of normal and cardiomyopathic (BIO 14.6) strains. Urine and blood were collected after 90 or 350 min in different groups. Cardiomyopathic hamsters more quickly lost their righting responses, eliminated ethanol more slowly, and had lower urine volume and sodium excretion than normal hamsters after ethanol injections. Plasma creatine kinase levels were normal in all animals tested, indicating no active skeletal or cardiac lesioning in the cardiomyopathic hamsters at the time of the experiment. Some factors which could contribute to the increased CNS and renal sensitivity to ethanol in cardiomyopathic hamsters include impaired ethanol metabolism, enhanced myocardial depression, and reduced atrial content of natriuretic peptides. The resultd do not owe to decompensated heart failure. Thus, the genetic mutation which causes skeletal and cardiac myopathy in these hamsters may also affect the metabolism and sensitivity to ethanol.

Pathophysiology of stone formation.

Urinary stone disease is a multifactorial disorder arising essentially from an abnormal combination of a number of urinary risk factors. In the case of calcium urolithiasis the main risk factors are a low urine volume, a high urinary pH, increased excretions of calcium, oxalate and uric acid and a low net level of inhibitory activity against the crystallization of calcium salts. The last mentioned, in turn, is dependent on the balance between the macromolecular inhibitors, including glycosaminoglycans, ribonucleic acid and acidic glycoproteins, and the promoters of crystallization such as Tamm-Horsfall mucoprotein. There is currently some debate as to whether or not an immunological factor might also be involved in the renal tubules, which results in crystals becoming bound to the renal epithelium.

Relationship of stone growth and urinary biochemistry in long-term follow-up of stone patients with idiopathic hypercalciuria.

One hundred and twenty-four male stone formers with idiopathic hypercalciuria were followed up for 4 to 27 years (mean 12.2). Twenty-eight received restricted calcium diet alone, 52 also received bendrofluazide, 11 cellulose phosphate, and 33 received mixtures of those drugs. Although urinary calcium values fell in all groups, the stone recurrence rate remained unacceptably high. Patients on cellulose phosphate fared worst and this drug seems unsatisfactory as a sole agent. Urinary calcium was highest in patients without stone recurrences, but in patients with stone activity a higher stone recurrence rate was associated with higher urinary calcium and lower urinary volume.

Environmental effects on urinary volumes, biochemical constituents and their inter-relation

This study has found low 24-h urine volumes in British expatriates in Saudi Arabia and suggests the possibility of urate stone formation in spite of the air-conditioned environment in which they were living. Urine volume was shown to be significantly correlated with calcium excretion in both sexes and to urate and sodium in males. Differences in 24-h urine concentrations of some but not all constituents between British-born subjects living in Britain and Saudi Arabia have been demonstrated.

Congenital anomalies of the adult bladder and urethra

To evaluate metabolic abnormalities in a contemporary pediatric population after their first stone episode. The incidence of pediatric nephrolithiasis is increasing and therefore the etiologies contributing to today's pediatric stone formation may also be changing.A retrospective review of all consecutive children presenting after their first kidney stone between 2000 and 2014 was performed. We compared demographic data, serum chemistry results, and 24-hour urine results and treatments.One hundred thirteen children with a mean age of 11 years (5 months to 18 years) who presented with their first kidney stone episode between 2000 and 2014 were evaluated. Sixteen patients (14%) were found to have an underlying genetic or systemic disease. Overall, there was a low rate of serum chemistry abnormalities. The most common abnormalities found within the 24-hour urine evaluation included low urine volume (89%) and hypocitraturia (68%). Hypercalciuria occurred rarely (11%).We identified a low rate of underlying genetic or systemic diseases contributing to modern pediatric stone presentation and an increased proportion of idiopathic stones. Our study differs from historical findings by identifying a low rate of hypercalciuria and a high rate of low urine volume and hypocitraturia, suggestive of changing metabolic abnormalities contributing to modern pediatric stone disease.

Review of risk factors in calcium oxalate urolithiasis

Calcium stone disease in the urinary tract is due to the formation of excessively large crystals and aggregates of calcium salts in urine. This phenomenon, in turn, is due to the combination of abnormalities in a number of potential urinary risk factors for the disorder. These include supersaturation-determining factors such as hypercalciuria, mild and severe hyperoxaluria, a persistently alkaline urine and a low urine volume; a reduced excretion of certain polyanionic inhibitors of crystallization of calcium oxalate, in particular glycosaminoglycans, RNA, and Tamm-Horsfall mucoprotein; and an increased excretion of certain promoters of crystallization such as urate and, perhaps, polymerized uromucoid. In turn, abnormalities in these urinary risk factors may be aggravated by or attributed to a number of epidemiological factors such as the age and sex of the individual, climate, season, stress, level of affluence, dietary and fluid intake and various metabolic and genetic disorders such as primary hyperparathyroidism, renal tubular acidosis and hereditary and enteric hyperoxaluria.

Estimation of glomerular filtration rate in conscious dogs following a bolus of creatinine

The renal clearance of creatinine was measured following orogastric administration in conscious dogs. Values of creatinine clearance were compared with simultaneously determined values of inulin clearance, when urine volume, glomerular filtration rate and volume status were acutely altered by a variety of experimental manoeuvres. At urine volumes greater than 20 microliters X min-1 X kg-1, creatinine clearance was not significantly different from inulin clearance. At low urine volumes there was some evidence of creatinine reabsorption. It is concluded that the bolus creatinine technique provides reliable estimates of glomerular filtration rate and is particularly applicable to long-term studies in conscious dogs.