Increased Urine Volume Research Articles

Interaction Between Determinants Governing Urine Volume in Patients With ADPKD on Tolvaptan and its Impact on Quality of Life

Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent genetic cause of kidney failure. Tolvaptan, a vasopressin 2 receptor antagonist, is the first drug with proven disease-modifying activity. Long-term treatment adherence is crucial, but a considerable fraction of patients discontinue treatment, because of aquaretic side effects. Twenty-four-hour urine was collected in 75 patients with ADPKD during up-titration of tolvaptan and, in combination with clinical characteristics, examined to identify factors influencing urine volume. Patient-reported outcomes were analyzed using the Short Form-12 (SF-12) and patient-reported outcomes questionnaires reporting micturition frequency and burden of urine volume. Initiation of therapy led to a large increase in urine volume followed by only minor further increase during up-dosing. Younger patients and patients with better kidney function experienced a larger relative rise. Twenty-four-hour urine osmolality dropped by about 50% after therapy initiation independently of dose, with a considerable proportion of patients achieving adequate suppression. Sodium and potassium intake turned out to be the only significant modifiable factors for urine volume after multivariate linear regression models, whereas age and weight could be identified as non-modifiable factors. No change in quality of life (QoL) was detected in relation to treatment or urine volume using SF-12 questionnaires, a finding that was further supported by the results of the patient-reported outcomes assessment. This study provides an in-detail analysis of factors associated with the degree of polyuria on tolvaptan and puts them into the context of QoL. These findings will contribute to optimized patient counseling regarding this treatment option in ADPKD.

Effect of Pharmacotherapy for Overactive Bladder on the Incidence of and Factors Related to Urinary Tract Infection: A Systematic Review and Meta-analysis.

The aim of this meta-analysis was to investigate the effect of pharmacotherapy for overactive bladder on the pathogenesis of urinary tract infection. A comprehensive search was performed in MEDLINE and the Cochrane Library using terms for overactive bladder, antimuscarinic agents, and beta 3-adrenoceptor agonists. The primary end point was the emergence of urinary tract infection after pharmacotherapy for overactive bladder. The secondary end point was the emergence of urinary retention, dysuria, and/or increased residual urine volume after overactive bladder treatment. Meta-analyses were conducted using random-effects models. A total of 35,939 patients in 33 trials (29 trials of antimuscarinic agents vs placebo, and 9 trials of beta 3-adrenoceptor agonists vs placebo) that included patients with overactive bladder were identified. At 1-3 months after treatment, the incidence of urinary tract infections was statistically significantly higher in the patients treated with antimuscarinic agents (RR: 1.23, 95% CI: 1.04, 1.45; P = .013) than in the placebo control group. The incidence of urinary tract infections was not increased in the patients treated with beta 3-adrenoceptor agonists (RR: 1.04, 95% CI: 0.76, 1.42; P = .796). Antimuscarinic agents also statistically significantly increased the risks of urinary retention, dysuria, and/or increased residual urine volume (RR: 2.88, 95% CI: 1.79, 4.63; P < .001), whereas beta 3-adrenoceptor agonists did not (RR: 1.26, 95% CI: 0.38, 4.14; P = .708). This meta-analysis showed that antimuscarinic agents statistically significantly increased the incidences of urinary tract infection and lower urinary tract symptoms and dysfunction, but beta 3-adrenoceptor agonists did not. To prevent urinary tract infection emergence, beta 3-adrenoceptor agonists might be safer than antimuscarinic agents.

Impact of urine cyclic AMP relative to plasma arginine vasopressin on response to tolvaptan in patients with chronic kidney disease and heart failure.

The clinical utility of tolvaptan in chronic kidney disease (CKD) patients with heart failure remains uncertain. The level of urine cyclic adenosine monophosphate (AMP) relative to plasma arginine vasopressin (AVP) indicates the residual function of the collecting ducts in response to AVP stimulation and might be a key to predicting response of tolvaptan. CKD patients who were hospitalized to treat their congestive heart failure refractory to conventional loop diuretics were considered to receive tolvaptan and included in this prospective study. The impact of urine cyclic AMP/plasma AVP ratio for prediction of response to tolvaptan, which was defined as any increase in urine volume at day 7 from day 0, was investigated. A total of 30 patients (median 75years old, 24 men, and median estimated glomerular filtration rate 14.4mL/min/1.73 m2) were included. As compared to baseline, urine volume increased at day 7 in 17 responders, whereas urine volume decreased at day 7 in 13 non-responders. Baseline urine cyclic AMP/plasma AVP ratio distributed between 0.25 and 4.01 with median 1.90. The urine cyclic AMP/plasma AVP ratio was a significant predictor of response to tolvaptan, which was adjusted for 6 potential confounders with a cutoff of 1.24. Baseline urine cyclic AMP/plasma AVP ratio is an independent predictor of response to tolvaptan in advanced CKD patients with heart failure. UMIN000022422.

Urinary Risk Profile, Impact of Diet, and Risk of Calcium Oxalate Urolithiasis in Idiopathic Uric Acid Stone Disease.

The role of diet in the pathogenesis of uric acid (UA) nephrolithiasis is incompletely understood. This study investigated the effect of dietary intervention on the risk of UA stone formation under standardized conditions. Twenty patients with idiopathic UA stone disease were included in the study. Dietary intake and 24 h urinary parameters were collected on the usual diet of the patients and a standardized balanced mixed diet. Although urinary UA excretion did not change, the relative supersaturation of UA decreased significantly by 47% under the balanced diet primarily due to the significant increase in urine volume and pH. Urinary pH was below 5.8 in 85% of patients under the usual diet, and in 60% of patients under the balanced diet. The supersaturation of calcium oxalate declined significantly under the balanced diet due to the significant decrease in urinary calcium and oxalate excretion and the increase in urine volume. Dietary intervention is a key component in the management of UA nephrolithiasis. Urinary calcium and oxalate excretion should also be monitored in patients with pure UA calculi to reduce the risk of mixed stone formation with calcium oxalate. Lower urinary pH in UA stone patients can only be partially explained by diet.

Augmentation of Natriuretic Peptide Bioactivity via Combined Inhibition of Neprilysin and Phosphodiesterase-9 in Heart Failure

BackgroundThe natriuretic peptides (NPs) are potent natriuretic/diuretic and vasodilatory factors, and augmentation of their levels or signaling via inhibition of the enzymes neprilysin (NEP) and phosphodiesterase 9 (PDE9), respectively, has beneficial actions in heart failure (HF). ObjectivesThe authors investigated dual enhancement of NP bioactivity by combining PDE9 inhibition and NEP inhibition in HF using an ovine model. MethodsEight sheep with pacing-induced HF received on 4 separate days intravenous PDE9 inhibition (PF-04749982), NEP inhibition (SCH-32615), PDE9 inhibition + NEP inhibition (PI+NI), and vehicle control treatment. ResultsCompared with the control treatment, NEP inhibition significantly increased plasma NP concentrations with a corresponding rise in second messenger cyclic guanosine monophosphate (cGMP), whereas PDE9 inhibition increased circulating cGMP with a negligible effect on NP levels. Combined PI+NI elevated plasma NPs to an extent comparable to that seen with NEP inhibition alone but further increased cGMP, resulting in a rise in the cGMP-to-NP ratio. All active treatments reduced mean arterial pressure, left atrial pressure, pulmonary arterial pressure, and peripheral resistance, with combined PI+NI further reducing mean arterial pressure and left atrial pressure relative to either inhibitor separately. Active treatments increased urine volume and sodium, potassium and creatinine excretion, and creatinine clearance, in association with rises in urine cGMP levels. PI+NI induced a significantly greater natriuresis and increase in urinary cGMP relative to either inhibitor singly. ConclusionsThe present study demonstrates for the first time that combined PI+NI has additional beneficial hemodynamic and renal effects when compared with either PDE9 inhibition or NEP inhibition alone. The superior efficacy of this 2-pronged augmentation of NP bioactivity supports PI+NI as a potential therapeutic strategy for HF.

S-27-2: RENAL WATER LOSS-INDUCED SKIN WATER CONSERVATION LEADS TO HIGH BLOOD PRESSURE IN SPONTANEOUSLY HYPERTENSIVE RATS

Objective: Although previous studies have demonstrated the pathophysiological basis of hypertension in basic and clinical sciences, the decisive mechanism of essential hypertension remains to be clarified. We recently reported that 5/6 nephrectomized rats exhibited renal water loss due to impaired renal concentration ability and that the renal water loss triggered suppression of transepidermal water loss (TEWL). This skin water conservation was achieved by skin vasoconstriction-mediated reduction in skin vascular mass, which increased blood pressure in 5/6 nephrectomized rats. In this study, we examined the effect of renal and skin water handling on high blood pressure in spontaneously hypertensive rats (SHR). Design and method: We used male 9 weeks old SHR and its control normotensive Wistar Kyoto rats (WKY) in this study. The rats were kept in metabolic cages to collect urine for 24 hours. We also collected urine under water deprivation. After the urine collection, the rats were sacrificed and their plasma and tissues were collected. Skin sodium and potassium content were measured by the ashing-flame photometer method. In a separate experiment, we compared blood pressure and TEWL in anesthetized SHR and WKY. Body temperature was raised by elevating room temperature. Results: Compared with WKY, SHR exhibited a significant increase in urine volume and a decrease in urine osmolality. There were no significant differences in plasma osmole concentrations, urinary sodium, potassium, and urea excretion between the groups. SHR showed significantly higher urine volume and lower urine osmolarity than WKY even in water deprivation, suggesting that SHR has renal water loss. SHR exhibited significantly lower TEWL and higher blood pressure and skin sodium and potassium content compared with WKY. Skin vasodilation induced by elevating body temperature significantly reduced blood pressure in SHR but not WKY. Conclusions: These findings suggest that renal water loss due to the impaired renal concentration ability induces suppression of TEWL and skin osmole accumulation in SHR. This skin water conservation leads to high blood pressure via skin vasoconstriction to reduce skin vascular mass and TEWL. Skin water conservation as a compensatory mechanism for renal water loss may be a key mechanism and novel therapeutic target for essential hypertension.

A 90-day repeated oral dose toxicity study of 2-Butylbenzo[d]isothiazol-3(2H)-one in rats

2-Butylbenzo[d]isothiazol-3(2H)-one (BBIT, CAS No. 4299-07-4) is widely used as an industrial antiseptic and antifungal agent. To investigate its toxicological properties and determine the no-observed-adverse-effect level (NOAEL), a 90-day repeated oral toxicological study of BBIT was conducted in Crl:CD (SD) rats at doses of 0 (vehicle control, corn oil), 30, 90, or 270 mg/kg/day. There was no mortality or abnormal clinical signs related to treatment in any group. Slightly decreased body weight and food consumption were observed in the 270 mg/kg group in females. Increased urine volume and kidney weight, increased liver weight, and thickening of the forestomach mucosa in autopsy were observed in both sexes in the 270 mg/kg group. Histopathological examination revealed that hyperplasia of the squamous epithelium of the forestomach with parakeratosis and/or hyperkeratosis was observed in both sexes in all the BBIT-treated groups. Moreover, centrilobular hypertrophy of hepatocytes was observed in both sexes of the 270 mg/kg group. Similarly, increased depositions of eosinophilic bodies and/or hyaline droplets in the proximal tubules of the kidney were observed among the male in the 270 mg/kg group. Based on the forestomach changes, NOAEL was judged to be less than 30 mg/kg/day in both sexes under this study’s conditions.

Efficacy of sacral transcutaneous electrical nerve stimulation in patients with overactive bladder refractory to anticholinergic treatment: a prospective multi-center study.

To determine whether sacral transcutaneous electrical nerve stimulation (S-TENS) is an effective treatment in patients refractory to anticholinergic drugs (Achs). A prospective multi-center study of patients with overactive bladder (OB) refractory to Achs treated with S-TENS from 2018 to 2021 was carried out. S-TENS was applied over 3 months. Symptom progression was assessed using the voiding calendar and the Pediatric Lower Urinary Tract Symptoms Score (PLUTSS), excluding questions 3 and 4 -referring to enuresis- so that progression of daytime symptoms only (LUTS variable) was analyzed. 66 patients -50% of whom were female- were included, with a mean age of 9.5years (range: 5-15). S-TENS significantly lowered PLUTSS (19.1 baseline vs. 9.5 final, p< 0.001) and LUTS (13.1 baseline vs. 4.8 final, p< 0.001). It also reduced the number of mictions (8.5 baseline vs. 6.4 final, p< 0.001), while increasing urine volume in the voiding records (214 ml baseline vs. 258 ml final, p< 0.001). Enuresis was the only variable refractory to S-TENS. Complication rate was 3% (2 patients with dermatitis in the S-TENS application area). S-TENS is effective and safe in the short-term in patients with OB refractory to Achs. Further studies assessing long-term efficacy and potential relapses are required.

Mineralocorticoids induce polyuria by reducing apical aquaporin-2 expression of the kidney in partial vasopressin deficiency.

The symptoms of diabetes insipidus may be masked by the concurrence of adrenal insufficiency and emerge after the administration of hydrocortisone, occasionally at high doses. To elucidate the mechanism underlying polyuria induced by the administration of high-dose corticosteroids in the deficiency of arginine vasopressin (AVP), we first examined the secretion of AVP in three patients in whom polyuria was observed only after the administration of high-dose corticosteroids. Next, we examined the effects of dexamethasone or aldosterone on water balance in wild-type and familial neurohypophyseal diabetes insipidus (FNDI) model mice. A hypertonic saline test showed that AVP secretion was partially impaired in all patients. In one patient, there were no apparent changes in AVP secretion before and after the administration of high-dose corticosteroids. In FNDI mice, unlike dexamethasone, the administration of aldosterone increased urine volumes and decreased urine osmolality. Immunohistochemical analyses showed that, after the administration of aldosterone in FNDI mice, aquaporin-2 expression was decreased in the apical membrane and increased in the basolateral membrane in the collecting duct. These changes were not observed in wild-type mice. The present data suggest that treatment with mineralocorticoids induces polyuria by reducing aquaporin-2 expression in the apical membrane of the kidney in partial AVP deficiency.

PS-BPB05-6: TOLVAPTAN INDUCES BODY FLUID LOSS AND ACTIVATION OF RENAL UREA-DRIVEN WATER CONSERVATION IN NORMAL RATS

Objective: We recently reported that body fluid loss models such as high salt-induced natriuresis, impaired urine concentration ability via kidney injury, and enhanced transepidermal water loss due to skin barrier dysfunction exhibit initial water loss and subsequent activation of the water conservation system in multiple organs. This activation of the water conservation system restores or even increases water content at the tissue level, which may be involved in abnormal body fluid distribution in various disease models. The water conservation system consists of renal urea recycling, the energy-intensive nature of hepato-muscular ureagenesis, and suppression of cardiovascular energy expenditure to save energy for ureagenesis. However, it is not clarified whether pharmacological fluid loss by diuretics activates the water conservation system. In this study, we examined the effects of water diuresis by tolvaptan, a selective vasopressin V2 receptor antagonist, on the water conservation system in normal rats. Design and method: 10-week-old male Sprague Dawley rats were fed with a control diet or a diet containing 0.1% tolvaptan. We measured water intake and urine volume for two weeks and also evaluated time-dependent changes in renal urea recycling and hepato-muscular ureagenesis in these rats. In addition, we also evaluated the effects of tolvaptan on blood pressure, heart rate, and renal sympathetic nerve activity by a radiotelemetry system in separate animals. Results: Tolvaptan markedly increased urine volume up to 126.7 ± 25.9 ml on day-1, which gradually decreased as much as one-third (48.1 ± 18.0 ml) on day-7. Tolvaptan significantly decreased body water content and increased plasma albumin concentration, an indicator of oncotic pressure, on day-1, suggesting that tolvaptan decreased body fluid and plasma volume on day-1. These changes in total body water content and plasma albumin concentration were restored on day-7. The restoration of body fluid on day-7 was associated with an increase in urea transporter A1-associated renal urea recycling. On the other hand, tolvaptan did not alter hepato-muscular ureagenesis or cardiovascular energy expenditure throughout the treatment. Conclusions: Tolvaptan induces initial body fluid loss by water diuresis and subsequent activation of renal urea recycling to restore the water loss. Activation of the water conservation system in addition to a rise in urine volume may be involved in the unknown distinct effect of the diuretics.

PS-BPB05-3: SERINE PROTEASE INHIBITION EXERTS AQUARETIC EFFECT AND DECREASES URINARY EXOSOMAL AQP2 LEVELS

Objective: Serine proteases (SPs) play pivotal roles in various physiological processes. In the kidney, it is reported that the epithelial sodium channel (ENaC) is activated via the proteolytic cleavage of α and γ subunits by SPs. We previously reported that a synthetic SP inhibitor camostat mesilate (CM) suppressed the cleavage of γENaC, thereby decreasing sodium reabsorption and blood pressure in aldosterone-infused rats. These results suggest the important roles of SPs within the kidney in the regulation of sodium homeostasis and blood pressure. Here, we aimed to identify novel physiological roles of SPs in the renal tubule and understand the mechanism of actions of SP inhibitors by administering CM into healthy rats. Design and method: Six-week-old male Sprague-Dawley rats were divided into control and CM groups. CM group rats were subcutaneously implanted with sustained-release pellets of CM (14 mg/day). After 24 h urine collection was performed, rats were sacrificed at day 7 to obtain blood and kidney samples. Urine volume was measured during the experimental period, and blood and urinary electrolytes, blood vasopressin, and renal tissue osmolality were measured. Protein expression of SPs and aquaporin-2 (AQP2) was analyzed by Western blotting. Results: CM significantly increased urine volume by approximately two-fold throughout the experimental period [urine volume (mL/day): control, 15.5 ± 2.4; CM, 30.6 ± 5.8], in a urinary sodium and osmolyte excretion-independent manner, which indicated that free water excretion had occurred. The vasopressin, potassium, and calcium levels in the blood and osmolality in the inner medulla, which affect free water reabsorption in the renal tubule, remained unchanged after CM administration. CM decreased urinary exosomal AQP2 excretion, suggesting that the AQP2 activity was suppressed in the collecting duct. These changes were reversed by the infusion of desmopressin. Such water diuretic action caused by CM was independent of its action on prostasin and TMPRSS4, which are serine proteases associated with sodium and water homeostasis, respectively. Conclusion: Our results revealed the association of SP inhibition with free water diuresis in the kidney and demonstrated that CM administration resulted in the downregulation of AQP2. The current findings suggest that SP inhibitors could become a new class of aquaretic drugs.

AW-NI-6: MINERALOCORTICOID RECEPTOR ACTIVATION LEADS TO HIGH BLOOD PRESSURE DUE TO BODY POTASSIUM AND WATER LOSS

Objective: Mineralocorticoid receptor (MR) activation is known to reduce renal Na+ elimination and increase body fluid, resulting in arterial hypertension. We have reported earlier that high salt intake, chronic renal failure and psoriasis occur blood pressure increases initiated by body water loss. Here we tested the hypothesis that DOCA treatment induces a similar adaptive water conservation response that also causes arterial hypertension. Design and method: Male C57BL/6J mice on the low-salt diet (&lt;0.1% NaCl) were divided into four groups: tap water (control), tap water with subcutaneous 25 mg DOCA (DOCA), 1% NaCl water with DOCA (DOCA salt), 1.44% NaHCO3 water with DOCA (DOCA NaBic). We performed continuous metabolic cage studies. Na+, K+, and water were measured in mice tissue by desiccation and consecutive dry ashing. Blood pressure was measured by telemetry. We also studied body composition, glucocorticoid-receptor (GR) protein/chromatin interaction, skin blood flow perfusion and renal vascular resistance. Metabolome and key enzyme activities of energy production in kidney, skeletal muscle and in liver were compared between four groups. Results: Compared to control mice, DOCA mice showed increased urine volume, lower urine osmolality and increased blood pressure. DOCA salt developed arterial hypertension within 3 days of the experiment (P &lt; 0.001, Fig. 1A). In DOCA salt mice, K+ and water loss occurs in the initiation phase of arterial hypertension (Fig. 1B), indicating solute and water loss from the intracellular space. Further water loss was then prevented by secondary Na+ accumulation, indicating that the initial MR-driven dehydration reverted back to normal body fluid level by means of Na+ accumulation. Additional physiological adaptation to DOCA salt-driven body water loss included increased vascular resistance (Fig. 1C) and catabolic amino acid breakdown (Fig. 1D). DOCA NaBic mice showed similar massive primary K+ loss and secondary Na+ retention, but no arterial hypertension occurred (Fig. 1A). While DOCA salt decreased skin blood flow, DOCA NaBic increased it (Fig. 1C). DOCA salt mice showed renal glutamine catabolism as well as muscle protein catabolism (Fig. 1D). This catabolic state was coupled with glucocorticoid receptor binding in skeletal muscle. Conclusions: DOCA salt leads to pronounced initial K+ and water loss with hypertension. Na+ retention occurs only secondarily and is a compensatory response that reverts initial body water loss back to normal body water levels. Additional NaBic feeding reveals that the blood pressure level in mice with MR activation is determined by changes in blood flow independent of body Na+ or water content.

Diuretic and Natriuretic Effects of Hesperidin, a Flavanone Glycoside, in Female and Male Hypertensive Rats

Hesperidin (HSP) is a major flavanone glycoside in citrus fruits, including sweet oranges and lemons. It demonstrates numerous pharmacological activities, such as antihypertensive effects and cardiac and kidney tissue protection. However, its effect on modulating renal function has yet to be properly explored. Female and male Wistar spontaneously hypertensive rats (SHR) were used to test the effect of HSP on renal function. The rats were divided into different groups, treated orally, and placed in metabolic cages for urine collection for 8 h. HSP, at doses of 0.3-3 mg/kg, led to an increase in urine volume in both female and male SHR. This effect was associated with increased Na+ elimination (3 mg/kg) without causing any change in K+ excretion or pH and conductivity values. When given HSP in combination with hydrochlorothiazide (HCTZ) or amiloride (AMLR), urine volume and Na+ elimination were significantly increased compared to the group that received only HSP. In relation to K+ excretion, the depleting effect of HCTZ and the sparing of AMLR prevailed in both groups. Pre-treatment with a non-selective cholinergic receptor antagonist, atropine, partially prevented HSP-induced diuresis and natriuresis in male SHR, but this effect was not demonstrated with the non-selective inhibitor of the enzyme cyclooxygenase, indomethacin. This study shows the diuretic action of HSP in hypertensive rats, an activity probably associated with the cholinergic pathway. Although various biological actions have already been defined for HSP, this pioneering research reveals its potential as a diuretic medicine.

Effects of Low-Dose Tolvaptan for Fluid Management After Cardiovascular Surgery.

Background: Perioperative management of body fluid levels after cardiovascular surgery with cardiopulmonary bypass is essential. Fluid management using tolvaptan with conventional diuretics is effective in maintaining urine output without worsening renal function. This study aimed to improve the in-out balance in the early perioperative phase using low-dose tolvaptan (3.75 mg/day). Methods and Results: This prospective, single-center, randomized, open-label study included 199 patients who underwent cardiovascular surgery with cardiopulmonary bypass in Kobe City Medical Center General Hospital between September 2018 and December 2020. Treatment with tolvaptan and loop diuretics (tolvaptan group; 99 patients) was compared with treatment with loop diuretics alone (control group; 100 patients) to evaluate achievement of preoperative body weight as the primary outcome. Secondary outcomes were urine volume, the incidence of worsening renal function (WRF), and postoperative paroxysmal atrial fibrillation (POAF). There was no significant difference between groups in the return to preoperative body weight on postoperative Day 6. The tolvaptan group had significantly increased urine volume (2,530 vs. 2,150 mL/day) and decreased total furosemide dose (24 vs. 32 mg) compared with the control group. No significant differences were observed in the development of WRF and POAF between the 2 groups. Conclusions: Although low-dose tolvaptan administration did not shorten the time to achieving preoperative body weight, it did significantly increase urine volume without WRF and POAF.

Multicenter, Open Label, Randomized Controlled Superiority Trial for Availability to Reduce Nocturnal Urination Frequency: Study Protocol for a TOP-STAR Study

Nocturia is a common disease in patients with type 2 diabetes mellitus that can reduce the quality of life. Sodium glucose co-transporter 2 (SGLT2) inhibitors increase the urine volume and are often discontinued when polyuria occurs, although tofogliflozin, which has a short half-life in the blood, may improve nocturia by managing hyperglycemia and hypertension, without aggravating nocturia. As excessive sodium intake worsens nocturia and increases urine volume, sodium restriction is also effective in managing nocturia. This multicenter, open-label, randomized parallel-group trial will examine 80 patients with type 2 diabetes who experienced nocturia. After the baseline examination, the patients are randomly stratified into two groups and receive tofogliflozin treatment with or without sodium restriction for 12 weeks. The primary outcome is nocturia frequency at 12 weeks. The secondary outcomes are the frequency of daytime urine, changes in urine volume, and changes in home blood pressure.

Clinical Effectiveness of Calcium Oxalate Stone Treatments

Introduction: Lowering kidney stone risk and urine calcium oxalate supersaturation is a primary clinical focus for kidney stone prevention and can be achieved with multiple strategies. Common strategies include advice to increase fluid intake, restrict dietary sodium, or prescribing a thiazide-type diuretic. We investigated how physicians make these decisions in real-world practice and evaluate their efficacy based on 24-h urine collections. Methods: We reviewed medical charts for 203 kidney stone formers with idiopathic calcium stones from University of Chicago Kidney Stone Clinic between 2005 and 2020. Patients had three 24-h urines before an initial pre-treatment clinic visit and one follow-up 24-h urine. We analyzed changes in urine composition based on treatment advice using t tests and ANOVA. Results: Patients who received advice to increase fluid intake had lower urine volume at baseline (1.5 vs. 2.5 L/day, p < 0.001) and larger increase in urine volume at follow-up (0.6 vs. 0.1 L/day, p < 0.001) compared to those who did not receive the advice. Patients who were advised to restrict dietary sodium had a higher urine sodium at baseline (208 vs. 139 mEq/day, p < 0.001), a larger reduction in urine sodium (−28 vs. 13 mEq/day, p = 0.002), and larger reduction in urine calcium (−74 vs. −28 mg/day, p = 0.005) compared with those not advised to restrict dietary sodium. Patients started on a thiazide had a higher baseline urine calcium (281 vs. 213 mg/day) and larger reduction in urine calcium (−83 vs. −9 mg/day, p < 0.001) compared with patients not started on a thiazide. In combination, thiazide prescriptions with dietary sodium restriction reduced urine calcium by 99 mg/day and reduced calcium oxalate supersaturation from 8.0 to 5.5 and calcium phosphate supersaturation from 1.4 to 1.0. Conclusion: Providers use 24-h urine data to guide treatment strategy decisions. These strategies achieved the intended effects on urine composition and lowered kidney stone risk.

The role of pulse indicator continuous cardiac output (PiCCO) and critical care ultrasound in volume status assessment during fluid resuscitation for and prognosis of septic shock patients.

To investigate whether pulse index continuous cardiac output (PiCCO) and critical care ultrasound are highly consistent in volume status assessment during fluid resuscitation for septic shock patients and analyze their influence on the prognosis of septic shock. Eighty septic shock patients treated by Huizhou Central People's Hospital during December 2018 and December 2020 were included and divided into a study group and a control group by the presence of volume responsiveness, with each group having 40 patients. The control group was subject to PiCCO-guided fluid resuscitation therapy, while the study group was given fluid resuscitation therapy guided by critical care ultrasound. Cardiac output, cardiac function, and catheter-related infection (CRI) were documented for intergroup comparison to confirm whether these two techniques were consistent with each other regarding their effects on resuscitation for and prognosis of septic shock patients. Mechanical ventilation duration (MVD) and intensive care unit (ICU) length of stay (LoS) were significantly shorter in the study group when compared with the control group, and the differences were statistically significant (p<0.05, respectively). In terms of blood pressure parameters, the two groups did not differ greatly in diastolic blood pressure (DBP), mean arterial pressure (MAP), systolic blood pressure (SBP), and central venous pressure (CVP) before resuscitation (p>0.05, respectively); at 6h(six hour) after resuscitation, DBP, MAP, SBP, and CVP were substantially increased in both groups as compared with the pre-resuscitation levels (all p<0.05), but the differences between the two groups lacked statistical significance (all p>0.05). Comparing urine volume and degrees of positive fluid balance at 6 h and 12 h after resuscitation, drastic increases in urine volume and positive fluid balance were observed in both groups at 12 h as compared with at 6 h (all p<0.05); nevertheless, the two groups showed no statistically significant difference in urine volume and positive fluid balance at 6 h or 12 h (p>0.05, respectively). With regards to prognosis, there was no statistically significant difference between the two groups in the number of cases of continuous renal replacement therapy (CRRT), dosage of vasoactive agents and 28-d mortality rate (all p>0.05). However, the incidence of CRI was markedly lower in the study group (0/40) as compared with the control group (5/40), and the difference was statistically significant (p<0.05). Both PiCCO and critical care ultrasound can help achieve favorable outcomes from resuscitation for septic shock patients. Compared with PiCCO, critical care ultrasound monitoring appears to be more effective in preventing CRI and reducing MVD and ICU LoS, thereby easing patients' medical burden.

The Efficacy and Safety of Tolvaptan in Heart Failure Patients with Congestive Signs: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: The aim of this study was to investigate the efficacy and safety of tolvaptan, as well as the impact of its treatment dose and duration in heart failure patients with congestive signs. Methods: The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched to collect data from all randomized controlled trials (RCT) examining the efficacy and safety of tolvaptan in heart failure patients with congestive signs compared with placebo or blank control until March 4, 2021. Urine volume, change in body weight, improvement in dyspnea, and reduction of edema were evaluated as efficacy indicators. All-cause mortality, worsening heart failure, and adverse events were considered safety indicators. The quality of eligible publications was assessed using the Cochrane risk of bias for RCTs. Results: Ten RCTs with 5,980 patients were included in this analysis. Compared with control, tolvaptan significantly reduced weight in the short term (day 1, 7 RCTs, weighted mean difference (WMD): –1.09, 95% confidence interval (CI): –1.27 to –0.91; day 2, 2 RCTs, WMD: –1.67, 95% CI: –3.00 to –0.33; day 7, 4 RCTs, WMD: –0.95, 95% CI: –1.25 to –0.66), increased urine volume (WMD: 1,825.72, 95% CI: 1,438.38–2,213.07), and relieved dyspnea (risk ratio (RR): 1.12, 95% CI: 1.05–1.19) without increasing the mortality rate (RR: 0.96, 95% CI: 0.87–1.06). Furthermore, the weight loss and increase in urine volume were not dose-dependent effects, and prolonged medication did not lead to sustained weight loss. In addition, there seemed to be more adverse events (RR: 1.17, 95% CI: 1.03–1.32) after treatment with tolvaptan. Further analysis revealed that patients treated with tolvaptan were more likely to report thirst (RR: 6.09, 95% CI: 3.37–11.00) and dry mouth (RR: 6.36, 95% CI: 4.09–9.90), as well as develop hypernatremia (RR: 12.76, 95% CI: 3.52–46.32). Conclusions: The meta-analysis shows that tolvaptan can improve congestion with no increase in mortality rate, but should be used to guard against adverse events. Deserve to be mentioned, the number of RCTs included was limited, suggesting that the observed results should be interpreted with caution. Additional robust clinical studies are warranted to validate the present findings.

Water balance and urinary parameters of lambs fed diets containing cactus cladodes varieties

AbstractThe water balance and urinary parameters of lambs fed diets containing cactus cladodes varieties were evaluated. Thirty-six uncastrated male Santa Inês lambs (22.0 ± 2.9 kg initial body weight) were distributed in a completely randomized design, with three treatments and 12 replicates. The animals were fed a control diet (Tifton-85 hay as exclusive roughage), Miúda or Orelha de Elefante Mexicana (OEM) cactus-based diets. Urine samples were collected 45 days after the introduction of the tested diets, and voluntary water intake was measured over 10 days, during the experimental period. Diets containing Miúda or OEM cactus caused a reduction of 68.35 and 77.03% in voluntary water intake, respectively. In addition, the Miúda cactus cladodes caused urinary alkalinization (pH = 8.14) and reduction in the urinary excretion index (UEI) and on the fractional excretion rate (FER) of total calcium (Ca). The diets with OEM cactus cladodes caused higher oxalates intake (6.21 g/day) and increase in urinary volume. Regardless of the variety, there was a reduction in the urinary concentrations of urea, creatinine, total proteins, Ca, phosphorus (P), UEI of urea and P, as well as in FER of P, compared to the control diet. Urinary Mg content and UEI of uric acid and Mg increased and FER of P decreased by diets supplemented with different varieties of cactus cladodes. In conclusion, the cactus cladodes increased water intake and retention, and diuresis in lambs, altered urine parameters, without compromising kidney function.

Evaluation and education of hydration and sodium status in a cool environment among Chinese athletes.

The aim of the study was to find the significance of several factors with parameters of urine tests and blood tests. Finally, we aimed at evaluating the percentage of athletes from the study sample regarding their hydration level. The current study is the prospective type and was conducted on Chinese athletes between June 2021 to April 2022. The study was done in 2 parts for obtaining measurements in the summer season and the winter season and then they were correlated between them. Urine and blood samples were evaluated for determining the required parameters. The parameters of the physical environment like temperature, relative humidity, precipitation, etc. were obtained from the concerned weather station for each day. It was observed that 14.5%, 59% and 26.5% of the female participants were found to have hyper-hydrated, euhydrated and dehydrated, respectively. While 17.57%, 69.69% and 12.74% of the males were classified as hyper-hydrated, euhydrated and dehydrated, respectively. The participants with hyper-hydrated were found to have increased urine volume (p<0.001), reduced specific gravity (p<0.001) and reduced-sodium level (p<0.001). The study found that there is a significant difference in sodium levels between gender and seasons. The level of serum osmolality is also significantly different between the whole study populations concerning combined seasons. In this way, many other parameters are evaluated by correlation with seasons and gender. Hence, this study has brought forward various important findings and gives an overall evaluation of hydration status.