Clinical relevance of proteinuria selectivity index and fractional excretion of sodium in patients with nephrotic syndrome.

Proteinuria selectivity index (PSI) is a potential tool for histological classification and prediction of treatment response in nephrotic syndrome, but evidence is insufficient. Clinical relevance of fractional excretion of sodium (FENa) in nephrotic syndrome remains largely unexplored. This multicenter retrospective study included patients with nephrotic syndrome who underwent kidney biopsy between January 2012 and June 2022. Optimal cutoffs for predicting complete remission based on PSI and FENa were determined using receiver operating characteristic curves. Patients were divided into two groups using these cutoffs and followed until complete remission. Of the 611 patients included, 177 had minimal change disease (MCD), 52 had focal segmental glomerulosclerosis (FSGS), and 149 had membranous nephropathy (MN). Median (interquartile range) PSI were 0.14 (0.09-0.19) for MCD, 0.33 (0.23-0.40) for FSGS, and 0.20 (0.14-0.30) for MN. FENa were 0.24 (0.09-0.68), 1.03 (0.50-2.14), and 0.78 (0.41-1.28). Patients with low PSI and FENa had a higher incidence of complete remission. Cox regression analyses demonstrated that both parameters were associated with achieving complete remission (HR 2.73 [95% CI 1.97-3.81] and HR 1.93 [95% CI 1.46-2.55], respectively). PSI and FENa may be useful for histological classification and predicting remission in nephrotic syndrome.

Hypokalaemic myopathy associated with iatrogenic hypercorticism in a cat.

Case summary: A 12-year-old castrated male domestic shorthair cat was referred for investigation of lethargy, hindlimb weakness with plantigrade stance and ventroflexion of the neck. The cat was fed a balanced diet and had received methylprednisolone acetate at a dose of 20 mg intramuscularly every 6 months for 6 years. On blood work, severe hypokalaemia and marked elevation of muscle enzymes were noticeable. The findings were suggestive of hypokalaemic myopathy. Urine fractional excretion of potassium (FEk) was moderately high (9.04%), and serum aldosterone was below the reference interval. An adrenocorticotropic hormone (ACTH) stimulation test was compatible with adrenal suppression. Upon hospitalisation, the patient was given intravenous (IV) Ringer lactate solution supplemented with potassium chloride and oral potassium citrate. The serum potassium concentration normalised by the fifth day of hospitalisation; therefore, IV potassium supplementation was suspended. The cat was discharged with oral potassium and the dose was gradually reduced over time. After 4 months, the cat was clinically normal; the serum potassium concentration remained within the normal range and the adrenal glands showed some response to ACTH stimulation. Potassium supplementation was therefore discontinued. One month later, the serum potassium concentration was still within normal limits and at the time of writing (7 months after presentation), no clinical signs had reoccurred. Relevance and novel information: This report describes a case of hypokalaemic myopathy associated with iatrogenic hypercorticism in a cat. This condition was successfully treated with supplementation of potassium and a complete clinical remission was achieved within 4 months.

Renal hypouricemia type 2 with SLC2A9 compound heterozygous variants: a case report of recurrent acute kidney injury triggered by low-intensity exercise.

Renal hypouricemia (RHUC) is a rare genetic disorder characterized by impaired uric acid reabsorption which leads to persistently low serum uric acid levels. This condition predisposes individuals to complications such as uric acid kidney stones and exercise-induced acute kidney injury (EIAKI). Although mutations in SLC22A12 and SLC2A9 are commonly implicated in RHUC, the precise pathophysiological mechanisms, particularly those contributing to AKI, remain incompletely understood. We report the case of a 30-year-old male who experienced recurrent episodes of EIAKI despite the absence of high-intensity exercise, suggesting the involvement of factors beyond the traditional risk. Genetic analysis confirmed the diagnosis of RHUC type 2 (RHUC2) and identified compound heterozygous variants of SLC2A9. Although these variants are not novel, this case contributes to the limited literature on RHUC2, particularly in male patients with recurrent EIAKI. These findings highlight the importance of maintaining a high index of suspicion for RHUC in cases of unexplained AKI, especially when recurrent episodes follow physical activity, and the need for targeted genetic testing for an accurate diagnosis. The genomic data related to this case are available in Mendeley Data: Vukkadala, Muralinath; Paladugu, Niranjana Rekha (2024), "Renal hypouricemia," Mendeley Data, V2, doi: 10.17632/7z84mkdgn9.2.

The Impact of 24 h Urinary Potassium Excretion on High-Density Lipoprotein Cholesterol and Chronic Disease Risk in Chinese Adults: A Health Promotion Study.

BACKGROUND: Research into the pivotal role of potassium in chronic diseases and their comorbidities remains scarce. Our aim is to elucidate the relationship between potassium and chronic diseases, including comorbid conditions, and to provide evidence-based recommendations for potassium intake in patients. METHODS: This study is anchored in a representative, population-based survey conducted in Zhejiang Province, China, in 2017, encompassing participants aged 18 to 69 years. Data collection included questionnaire responses, physical measurements, and biological samples, obtained through a multistage cluster random sampling method. A subset of 1496 participants provided complete 24 h urine samples. RESULTS: The median age of the participants was 48.0 years (interquartile range [IQR] 24.0), with 51.1% being female, and hypertension was identified in more than one third (35.6%) of the participants. The prevalence of diabetes was approximately 9.0%, dyslipidemia was found in 34.2%, and microalbuminuria in 8.8%. The 24 h urinary excretion levels were 3613.3 mg/24 h (IQR 2161.7) for sodium and 1366.0 mg/24 h (IQR 824.9) for potassium, respectively. Potassium excretion exhibited an inverse relationship with blood pressure. Furthermore, a positive correlation was observed between potassium excretion and high-density lipoprotein cholesterol (HDL-C) levels, with an elevation of 0.03 mmol/L (95% confidence interval [CI] 0.00 to 0.05). In binary logistic regression analysis, individuals in the fourth quartile of potassium excretion (Q4) exhibited an odds ratio (OR) of 0.56 (95% CI 0.36-0.87) for hypertension compared to those in the first quartile (Q1). Urinary potassium excretion was inversely associated with low HDL-C levels, with Q4 individuals having 0.62 times the odds of having low HDL-C levels (OR, 0.62; 95% CI 0.39-1.00) compared to Q1. CONCLUSIONS: Potassium excretion demonstrated a direct negative correlation with certain comorbidities. This study underscores the pivotal role of potassium in the management of chronic diseases and associated comorbidities, thereby highlighting the significance of potassium in both public health initiatives and clinical practice.

Association of Urinary Sodium, Potassium, and the Sodium-to-Potassium Ratio with Impaired Kidney Function Assessed with 24-H Urine Analysis.

Background: Albuminuria and albumin excretion rate (AER) are important risk factors for chronic kidney disease (CKD) development. Despite the extensive evidence of the influence of sodium and potassium on cardiovascular health, the existing evidence regarding their impact on albuminuria and kidney disease is limited and inconsistent. Our study aimed to assess the correlation between urinary sodium and potassium excretion, and the sodium-to-potassium ratio (Na/K ratio) with impaired kidney function, particularly the AER and albuminuria. Materials and Methods: Data were collected from the Lithuanian NATRIJOD study. A total of 826 single 24-h urine samples from individuals aged 18 to 69 were collected and analyzed for their sodium and potassium levels, Na/K ratio, and AER. Albuminuria was defined as an AER exceeding 30 mg/24 h. Results: The participant mean age was 47.2 ± 12.1 years; 48.5% of the participants were male. The prevalence of albuminuria was 3%. Correlation analysis revealed a positive correlation between AER and urinary sodium excretion (rs = 0.21; p < 0.001) and urinary potassium excretion (rs = 0.28; p < 0.001). In univariate linear regression analysis, sodium and potassium excretion and the Na/K ratio were significant AER predictors with ß coefficients of 0.028 (95% CI: 0.015; 0.041; p < 0.001), 0.040 (95% CI: 0.003; 0.077; p = 0.035), and 1.234 (95% CI: 0.210; 2.259; p = 0.018), respectively. In the multivariable model, only urinary sodium excretion remained significant, with a ß coefficient of 0.028 (95% CI: 0.016; 0.041). Potential albuminuria predictive factors identified via univariate logistic regression included urinary sodium excretion (OR 1.00; 95% CI: 1:00; 1.01) and the Na/K ratio (OR 1.53; 95% CI: 1.11; 2.05). However, these factors became statistically insignificant in the multivariate model. Conclusions: Urinary sodium and potassium excretion and the Na/K ratio are significantly associated with kidney damage, considering the assessed 24-h albumin excretion rate and presence of albuminuria content.

Dietary bamboo charcoal powder ameliorates high-fat diet-induced hyperlipidemia by enhancing fecal lipid excretions in Sprague-Dawley rats.

Introduction: Bamboo charcoal powder (BCP) is increasingly used as a food colorant. This study aims to evaluate the effects of BCP consumption on improving high-fat diet-induced hyperlipidemia. Methods: Fifty male SD rats were randomly assigned into five groups, with 10 rats in each group: the control group was fed a low-fat diet (LFD); the model control group was fed a high-fat diet (HFD); the low-BCP dose group was fed a HFD and given 2.81 g of BCP/kg of body weight (BCP-L) by gavage; the medium-BCP dose group was fed a HFD and given 5.62 g of BCP/kg of body weight (BCP-M) by gavage; the high-BCP dose group was fed a HFD and given 11.24 g of BCP/kg of body weight (BCP-H) by gavage. Results: After 90 days, the consumption of BCP caused a decrease in body weight, plasma lipids (triglyceride, cholesterol, and low-density lipoprotein (LDL)), liver triglyceride, and cholesterol levels, and liver histopathological scores. BCP caused a significant increase in superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) in liver tissues. BCP also led to an increase in 72-h fecal dry weight and crude fat in a rat metabolic cage. The analysis of fecal samples with liquid chromatography time-of-flight mass spectrometry (LC-Q-TOF-MS) showed that the biomarkers associated with BCP consumption were mainly related to fatty and amino acid metabolism. Notably, BCP treatment significantly promoted linoleic acid metabolism. Discussion: These results suggest that BCP may have a preventive effect against diet-induced hyperlipidemia through the promotion of fecal fat excretion. BCP may potentially be used as an alternative functional food component for people with diet-induced hyperlipidemia.

Association of urinary albumin excretion with all-cause and cardiovascular mortality among patients with rheumatoid arthritis: a national prospective study.

Background: Rheumatoid arthritis (RA) patients suffering from chronic renal insufficiency tend to exhibit subtle manifestations at the beginning. Urine albumin to creatinine ratio (ACR) is a sensitive indicator for early assessment of renal function. However, it is unclear whether it serves as an independent risk factor influencing the prognosis of RA patients. Methods: National Health and Nutrition Examination Survey (NHANES) data from 2009-2018 were included. Kaplan-Meier (K-M) curves were plotted to compare the cumulative survival probability of RA patients with different urinary albumin excretion. The association of ACR with mortality among RA patients was investigated with Cox regression model, restricted cubic spline (RCS) and stratified analyses. The prognostic efficacy of ACR and estimated glomerular filtration rate (eGFR) was evaluated by receiver operating characteristic (ROC) curves. Results: The Cox regression model adjusted with covariates showed a 53% (HR 1.53, 95% CI 1.06-2.21) increase in all-cause mortality and a statistically non-significant increase in cardiovascular disease (CVD) mortality in RA patients with microalbuminuria (30mg/g ≤ACR<300mg/g). ACR≥300mg/g was associated with an increase in all-cause mortality (HR 2.62, 95% CI 1.55-4.45) and CVD mortality (HR 5.67, 95% CI 1.96-16.39). RCS demonstrated a nonlinear correlation between ACR and all-cause mortality in RA patients with microalbuminuria. Subgroup analysis showed that CVD mortality was higher in RA patients with microalbuminuria characterized by the following features: female, other ethnicity, eGFR≥60 ml/min/1.73 m2, hypertension or hyperlipidemia. Compared with eGFR, ACR provided better prognostic efficacy than eGFR with higher values of the area under the curve (AUC) for all-cause mortality (AUC=0.683, 95% CI 0.613-0.754) and CVD mortality (AUC=0.681, 95% CI 0.541-0.820). Conclusion: ACR is an independent risk factor affecting the prognosis of RA patients. The all-cause mortality was increased in RA patients with albuminuria. There was an upward trend in the CVD mortality of those with macroalbuminuria when ACR increased.

Ursodeoxycholic Acid for Trans Intestinal Cholesterol Excretion Stimulation: A Randomized Placebo Controlled Crossover Study.

BACKGROUND: The trans intestinal cholesterol excretion (TICE) pathway is a potential therapeutic target to reduce plasma low-density lipoprotein (LDL) cholesterol levels. TICE encompasses the direct excretion of cholesterol by enterocytes into feces. In mice, TICE has been shown to be stimulated by a hydrophilic bile acid pool, resulting in increased fecal neutral sterol loss and reduced plasma cholesterol levels. We investigated whether treatment with a hydrophilic bile acid, ursodeoxycholic acid (UDCA), would increase fecal neutral sterols in humans as a proxy for TICE. METHODS AND RESULTS: We performed a randomized, double-blind, placebo-controlled, cross-over trial in 20 male participants aged >18 years, with plasma LDL cholesterol levels ≥2.6 mmol/L. After a run-in period of ezetimibe 20 mg once daily for 3 weeks, patients were randomized to UDCA 600 mg or placebo orally once daily for 2 weeks. After a 3 week washout, patients underwent the alternate treatment. At baseline, mean (SD) age, body mass index, and plasma LDL cholesterol were 59±11.3 years, 26.4±3.1 kg/m2, and 3.9±0.8 mmol/L, respectively. After UDCA treatment, the plasma bile acid hydrophobicity index was reduced compared with placebo (-118.7% versus +2.3%, P<0.001). The fecal neutral sterols did not change (-5.8% versus +18.8%, P=0.51) and treatment with UDCA increased LDL cholesterol with 0.39 mmol/L (+8.1% versus -3.64%, P=0.002) when compared with placebo. CONCLUSIONS: UDCA in combination with ezetimibe increased plasma bile acid hydrophilicity in healthy subjects with LDL cholesterol levels >2.6 mmol/L but did not result in increased fecal neutral sterols or decreased LDL cholesterol. This suggests that TICE is not stimulated by an increase in the hydrophilicity of the bile acid pool in humans.

Diet rich in soluble dietary fibres increases excretion of perfluorooctane sulfonic acid (PFOS) in male Sprague-Dawley rats.

Perfluorooctane sulfonic acid (PFOS) belongs to a large group of anthropogenic compounds with high persistency named per- and polyfluorinated substances (PFAS). Widespread use from industry to household appliances and food-contact materials contributes to PFAS exposure with food as the primary source. Association studies suggest that vegetables and fibre rich diet may reduce PFOS levels in humans, but experimental data remain limited. Here, we investigated PFOS uptake and wash-out after seven days of PFOS (3 mg/kg/day) in two groups of rats (N = 12 per group) fed diets either high (HF) or low (LF) in soluble dietary fibres. Two control groups (N = 12/group) were fed the same diets without PFOS. Changes in pH and transit time were monitored alongside intestinal and faecal microbiota composition. We quantified systemic and excreted, linear and branched PFOS. Results revealed significantly lower pH and faster intestinal transit in the HF groups. Importantly, HF rats had lower serum PFOS concentrations and higher PFOS concentrations in caecal content and faeces, indicating a more efficient excretion on the fibre rich diet. In both dietary groups, PFOS affected the gut microbiota composition. Our results suggest that a diet rich in soluble dietary fibres accelerates excretion of PFOS and lowers PFOS concentration in serum.

Kinetic analysis of D-Alanine upon oral intake in humans.

D-Alanine, a rare enantiomer of alanine, can potentially alleviate the worsening of viral infections and maintain circadian rhythm. This study aimed to analyze the kinetics of D-Alanine upon oral intake. Five healthy volunteers were administered D-Alanine as a single oral dose at 11,236 or 33,708 µmoL (1-3 g). Upon intake of the lower dose, the plasma level of D-Alanine reached its peak concentration of 588.4 ± 40.9 µM with a peak time of 0.60 ± 0.06 h. The compartment model estimated the clearance of D-Alanine at 12.5 ± 0.3 L/h, or 208 ± 5 mL/min, distribution volume of 8.3 ± 0.7 L and half-life of 0.46 ± 0.04 h, suggesting a rapid clearance of D-Alanine. The peak concentration and area under the curve increased proportionally upon intake of the higher dose, while the clearance, distribution volume and half-life did not. The urinary ratio of D-Alanine per sum of D- and L-Alanine reached its peak of nearly 100%, followed by a slow decline. The peak time of the urinary ratio was 1.15 ± 0.15 h, showing a time lag of blood to urine excretion. Fractional excretion, a ratio of the clearance of a substance per a standard molecule in kidney, of D-Alanine increased from 14.0 ± 5.8% to 64.5 ± 10.3%; the latter corresponded to the urinary clearance of D-Alanine as about 77 mL/min for an adult, with a peak time of 1.90 ± 0.56 h. D-Alanine was quickly absorbed and appeared in blood, followed by urinary excretion. This kinetic analysis increases our fundamental knowledge of the oral intake of D-Alanine for the chronic dosing. Trial number: #UMIN000050865. Date of registration: 2023/6/30.

Long-Term Excretion of Roxadustat in Urine.

Roxadustat (FG-4592), an orally active hypoxia-inducible factor prolyl hydroxylase stabilizer, has been shown to enhance erythropoiesis by increasing endogenous erythropoietin. It is indicated for the treatment of anemia and chronic kidney disease and is approved for clinical use in several countries, including the European Union, Japan and others. Due to its reasonably anticipated performance-enhancing effect in athletes, roxadustat is prohibited for use in sports at all times. A few cases of adverse analytical findings in routine doping controls have been reported worldwide, some of which were claimed to be the result of contaminated dietary supplements. The present study offers new data demonstrating the long-term excretion pattern of roxadustat. Even after a single-dose administration, roxadustat can remain detectable in urine for 8 months, albeit at very low concentrations (<10 pg/mL). Following three times a week treatment with 70 to 100 mg of roxadustat, the drug was still detectable in the urine of anemic patients for between 9 and 18 months after treatment was discontinued. Lastly, an athlete who admitted use of roxadustat for almost a year (50 mg 3 to 5 times a week) has now tested positive multiple times over the course of 15 months (the first test being 12 months after the drug was discontinued), with an estimated concentration of roxadustat between 3 and 8 pg/mL. Altogether, these findings indicate the unusually prolonged terminal excretion kinetics of roxadustat, a property that testing authorities should consider in their results management process.

Creatinine clearance/eGFR ratio: a simple index for muscle mass related to mortality in ICU patients.

INTRODUCTION: In patients admitted to the intensive care unit (ICU), muscle mass is inversely associated with mortality. Although muscle mass can be estimated with 24-h urinary creatinine excretion (UCE), its use for risk prediction in individual patients is limited because age-, sex-, weight- and length-specific reference values for UCE are lacking. The ratio between measured creatinine clearance (mCC) and estimated glomerular filtration rate (eGFR) might circumvent this constraint. The main goal was to assess the association of the mCC/eGFR ratio in ICU patients with all-cause hospital and long-term mortality. METHODS: The mCC/eGFR ratio was determined in patients admitted to our ICU between 2005 and 2021 with KDIGO acute kidney injury (AKI) stage 0-2 and an ICU stay ≥ 24 h. mCC was calculated from UCE and plasma creatinine and indexed to 1.73 m2. mCC/eGFR was analyzed by categorizing patients in mCC/eGFR quartiles and as continuous variable. RESULTS: Seven thousand five hundred nine patients (mean age 61 ± 15 years; 38% female) were included. In-hospital mortality was 27% in the lowest mCC/eGFR quartile compared to 11% in the highest quartile (P < 0.001). Five-year post-hospital discharge actuarial mortality was 37% in the lowest mCC/eGFR quartile compared to 19% in the highest quartile (P < 0.001). mCC/eGFR ratio as continuous variable was independently associated with in-hospital mortality in multivariable logistic regression (odds ratio: 0.578 (95% CI: 0.465-0.719); P < 0.001). mCC/eGFR ratio as continuous variable was also significantly associated with 5-year post-hospital discharge mortality in Cox regression (hazard ratio: 0.27 (95% CI: 0.22-0.32); P < 0.001). CONCLUSIONS: The mCC/eGFR ratio is associated with both in-hospital and long-term mortality and may be an easily available index of muscle mass in ICU patients.

The fate of a Solanum steroidal alkaloid toxin in the cabbage looper (Trichoplusia ni).

Plants produce complex chemical defenses against herbivores, resulting in the emergence of detoxification strategies in phytophagous insects. While enzymatic detoxification and target site mutagenesis are well-documented, the quantitative contribution of excretion remains less studied. We focus on the cabbage looper (Trichoplusia ni), a generalist herbivore, to elucidate the detoxification of a steroidal alkaloid, solanidine, produced in potato (Solanum tuberosum). Through larval feeding experiments and chemical analysis of metabolites using high-resolution mass spectrometry, we identify solanidine 3-O-ß-glucopyranoside and solanidine 3-phosphate as major metabolization products of solanidine. Glycosylation and phosphorylation reactions have not previously been observed in cabbage looper. Modified solanidine derivatives exhibit reduced lipophilicity, preventing passive transport as predicted by physicochemical analyses, and only solanidine was detected in body tissue. In addition, the metabolism of solanidine in a T. ni mutant strain with midgut cadherin protein knocked out was also investigated to examine the potential role of the cadherin, an important receptor for Bt toxins, in steroidal alkaloid detoxification. T. ni cadherin-knockout strain showed lower solanidine conversion (33.9% ± 2.2) and uptake (27.41 ± 0.49 nmol/g) compared to the wild-type strain (51.3% ± 4.1, 33.66 ± 2.48 nmol/g) but similar excretion kinetics. Although solanidine negatively impacted the feeding performance of both strains the cadherin-knockout does not affect the feeding performance. Our study expands the metabolization enzyme repertoire in cabbage loopers, emphasizing the complexity of detoxification mechanisms in generalist herbivores.

Validation of a Remote Sampling Sensor for Measuring Urine Volume and Nitrogen Concentration in Grazing Dairy Cattle.

The purpose of this research was to validate a urine sensor (Lincoln University PEETER V2.0, Canterbury, New Zealand) that records the time and volume of urination events for dairy cows in addition to collecting a proportional urine sample from all urination events. Sixteen multiparous Holstein × Jersey mid-lactating cows (101 ± 5 days in milk, 498 ± 24.2 kg body weight, 26.2 ± 3.07 kg/d milk yield; mean ± standard deviation) were allocated herbage diets ranging in protein and sodium content to generate a range of urine volumes and urine nitrogen (UN) concentrations. Total collection of individual urination events occurred during a 72-h measurement period where PEETER V2.0 sensors were attached to cows. A mixed model ANOVA using lme4 package (version 1.1-35.5) in R (version 4.3.3) were used to compare the means. The average urine event size was 2.65 ± 1.1 L for total collection by observers and 2.68 ± 1.1 L as recorded by the sensor (mean ± standard deviation; p = 0.730). The urine nitrogen concentration was 5.76 ± 1.2 g N/L for samples collected by observers and 5.85 ± 1.3 g N/L for the samples collected by the sensor (p = 0.583). The calculated UN excretion was 156 ± 45.1 g/day for direct measurements and 162 ± 40.0 g/day for the sensor (p = 0.539. Contrasts with simultaneously measured data were undertaken using Lin's Concordance Correlation Coefficient (CCC) and a Pearson correlation coefficient (r). Correlations between the actual values and sensor values were strong, with little to moderate variability in the urine volume (CCC = 0.936, r = 0.937; n = 222), UN concentration (CCC = 0.840, r = 0.837, n = 48) and total UN excretion (CCC = 0.827, r = 0.836, n = 24). Considering the findings, the PEETER V2.0 urine sensor has the potential to reliably measure urine volumes and UN concentrations for estimations of the UN excretion of dairy cattle under grazing systems.

Effectiveness of ultra-/very-high-frequency oscillations combined with helium-oxygen gas mixture in a rabbit model.

High-frequency oscillatory ventilation (HFOV) at frequencies of approximately 15 Hz is associated with optimal CO2 excretion. Higher frequencies using a nitrogen-oxygen gas mixture worsen CO2 excretion. An in vitro experiment using HFOV and a helium-oxygen gas mixture showed a significant increase in CO2 transport, which increased with increases in ventilation frequency. We hypothesised that in HFOV, the change in the arterial partial pressure of CO2 (PaCO2) would be greater at frequencies above 15 Hz when combined with helium-oxygen gas mixture administration. We tested this hypothesis in a hypoventilated healthy rabbit model by administering a helium-oxygen gas mixture at 15, 25, 35, and 45 Hz frequencies. One-way repeated measures ANOVA showed a significant decrease in PaCO2 among the four ventilation frequency groups. Post-hoc analysis showed significant differences between 15 and 35 Hz frequencies and between 15 and 45 Hz frequencies. The mean (standard error) decrease of PaCO2 was 10.8 (2.2), 14.1 (2.3), 21.3 (3.3), and 23.1 (2.5) mmHg at 15, 25, 35, and 45 Hz, respectively. Combination therapy of helium-oxygen gas mixture and high-frequency oscillation using ultra/very high frequencies (35-45 Hz) was associated with a greater PaCO2 decrease than that using the standard frequency (15 Hz).

Time course of plasma urea and urinary urea excretion in patients with a prolonged ICU stay.

Whereas urinary creatinine excretion (UCE) is an established marker of muscle mass, both in critically ill and non-critically ill patients, analysis of urinary urea excretion (UUE) may allow estimation of proteolysis that is associated with critical illness. We evaluated the time courses of plasma urea and creatinine as well UUE and UCE in critically ill patients with a prolonged ICU stay. Our goal was to evaluate changes in plasma urea and creatinine in conjunction with their urinary excretion, to get a better understanding of urea handling in ICU patients. From 2002 to 2021, plasma urea and creatinine, UUE and UCE were determined in routinely obtained 24 h urine samples between ICU admission and day 30, in adult patients with an ICU-stay ≥ 28d. Urea-to-creatinine ratios in plasma and urine were calculated. Patients with stage 3 acute kidney injury (AKI) were excluded. Analyses were performed separately for females and males and for patients with and without acute renal failure to account for respectively differences in muscle mass and impaired renal function. Of 47,120 patients, who were admitted to the ICU between 2002 and 2021, 638 patients met the inclusion criteria. During the first 10 days mean ± SD plasma urea increased from 9.7 ± 6.0 mmol/L at ICU admission to 12.4 ± 7.9 mmol/L (P < 0.001) on day 11 and decreased afterwards with a rate of 0.1 mmol/l/d. UUE peaked at 590 ± 317 mmol/day on day 13 whereas UCE peaked already on day 4. Males had higher plasma urea, plasma creatinine, UUE and UCE than females. Plasma and urinary urea-to-creatinine ratio (UCR) stabilized after day 7, with a gradual increase in plasma UCR and urinary UCR between day 7 and day 30. Similar courses, although less pronounced, were seen in patients without AKI. The course of urea in critically ill patients is characterized by an initial rise of both plasma urea and urinary urea excretion, presumably due to increased catabolism of endogenous and exogenous protein in the first week of ICU admission. Subsequently, UUE and UCE declined steadily in a rate that was comparable to the known loss of muscle mass during ICU admission of approximately 1%/day.

Association between urine creatinine excretion and bone mineral density in chronic kidney disease: Results from the KNOW-CKD study.

BACKGROUND: Decreased lean body mass or muscle mass is associated with decreased bone mineral density in individuals with preserved renal function. However, the association between muscle mass and bone mineral density in chronic kidney disease (CKD) patients is not well known. The aim of this study was to assess the relationship between muscle mass estimated from urine creatinine (UCr) and bone mineral density in Korean CKD patients. METHODS: This cross-sectional study analyzed 1872 participants from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) cohort. Participants underwent UCr (g/day) and bone mineral density measurements, which were measured at the lumbar spine, total hip, and femoral neck by dual-energy X-ray absorptiometry. Patients were divided into three groups according to the tertiles of 24 h UCr (T1-T3). RESULTS: The mean values for 24 h urine creatinine of T1, T2, and T3 were 0.83 ± 0.23 g, 1.18 ± 0.24 g, and 1.55 ± 0.38 g, respectively. A total of 172 patients were diagnosed with osteoporosis. The number of patients in each group was 92 (14.4%) in T1, 45 (7.3%) in T2, and 35 (5.7%) in T3. The odds ratio (95% confidence interval) for osteoporosis was 0.37 (0.20-0.69) for 1 g/day increase of UCr. Compared with T1, the odds ratios (95% confidence interval) for osteoporosis were 0.58 (0.39-0.87) for T2 and 0.51 (0.32-0.80) for T3. CONCLUSION: Low 24-h UCr was associated with low bone mineral density. Low 24 h UCr was significantly and independently associated with osteoporosis in Korean pre-dialysis CKD patients. Further research is warranted to verify the influence of muscle mass on bone health in CKD.

Possible Metabolic Remodeling based on de novo Biosynthesis of L-serine in Se- Subtoxic or Deficient Mammals.

Current research point to an increased risk of diabetes with selenium (Se) intake beyond the physiological requirement used to prevent cancers. The existing hypothesis of "selenoprotein overexpression leads to intracellular redox imbalance" cannot clearly explain the U-shaped dose-effect relationship between Se intake and the risk of diabetes. In this review, it is speculated that metabolic remodeling based on the de novo biosynthesis of L-serine may occur in mammals at supranutritional or subtoxic levels of Se. It is also speculated that a large amount of L-serine is consumed by the body during insufficient Se intake, thus resulting in similar metabolic reprogramming. The increase in atypical ceramide and its derivatives due to the lack of L-serine may also play a role in the development of diabetes.

To analyse the correlation between UAER and eGFR and the risk factors for reducing eGFR in patients with type 2 diabetes.

OBJECTIVE: To analyse the correlation between urinary albumin excretion rate (UAER) and estimated glomerular filtration rate (eGFR) and the risk factors for reducing eGFR in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 431 T2DM patients admitted between January 2019 and March 2020 were selected and divided into two groups according to eGFR level. Comparing the differences between baseline data and clinical indicators, multivariate logistic regression was used to analyse the risk factors of eGFR reduction and to analyse the association between UAER and eGFR. RESULTS: In total, 167 patients were included in the study group and 264 patients were included in the conventional group. The study group participants were older, had longer diabetes duration, and had higher fatty liver, peripheral vascular disease (PVD), hypertension prevalence, and mean body mass index (P < 0.05). The levels of various indicators were lower than those of the conventional group (P < 0. 05). Additionally, PVD, nocturnal systolic blood pressure, fatty liver, and beta-2-microglobulin (ß 2-MG) were independent risk factors for eGFR decline, with high density lipoprotein (HDL) and fasting C-peptide (CP) as protective factors. There was no obvious correlation between UAER and eGFR. CONCLUSION: Peripheral vascular disease, systolic blood pressure, fatty liver, and beta-2-microglobulin are risk factors for decreased eGFR levels in patients with T2DM, which should be applied for control DKD. HDL and fasting CP have important effects on maintaining eGFR, and blood pressure and fasting CP can be used as new targets for subsequent diabetic kidney disease treatment.

Changes in Central Sensitivity to Thyroid Hormones vs. Urine Iodine during Pregnancy.

INTRODUCTION/AIM: Central sensitivity to thyroid hormones refers to the responsiveness of the hypothalamic-pituitary-thyroid (HPT) axis to changes in circulating free thyroxine (fT4). Although dose-response relationships between thyroid hormones per se and urinary iodine (UI) levels have been observed, central sensitivity to thyroid hormones in relation to UI remains unexplored. The aim of the present study was to evaluate central sensitivity to thyroid hormones (by means of the Thyroid Feedback Quantile-based Index [TFQI], which is a calculated measure, based on TSH and fT4, that estimates central sensitivity to thyroid hormones) in pregnancy and to assess whether it differs according to gestational age and/or iodine intake. MATERIALS AND METHODS: One thousand, one hundred and two blood and urine samples were collected from pregnant women (with a mean age ± SD of 30.4 ± 4.6 years) during singleton pregnancies; women with known/diagnosed thyroid disease were excluded. Specifically, TSH and fT4, anti-thyroid peroxidase antibodies and UI were measured in each trimester and at two months postpartum, while the TFQI was calculated for all the study samples. After the elimination of outliers, statistical analysis was conducted with analysis of variance (ANOVA) for the variables versus time period, while Pearson's correlation was used to assess the TFQI versus UI. RESULTS: The mean TFQI index ranged from -0.060 (second trimester) to -0.053 (two months postpartum), while the corresponding UI was 137 and 165 µg/L, respectively. The TFQI-UI correlation was marginally negative (Pearson r: -0.323, p: 0.04) and significantly positive (r: +0.368, p: 0.050) for UI values over 250 µg/L, in the first and the second trimesters of pregnancy, respectively. DISCUSSION: The TFQI is a new index reflecting central sensitivity to thyroid hormones. A lower TFQI indicates higher sensitivity to thyroid hormones. In our sample, the TFQI was mainly positively related to iodine intake in the second trimester of pregnancy (following the critical period of organogenesis). Thus, the observed changes in the TFQI may reflect the different ways of the central action of thyroid hormones, according to the phase of pregnancy. These results have the potential to enhance our comprehension of the changes in the HPT axis' function via variations in central sensitivity to thyroid hormones and its interplay with nutritional iodine status during pregnancy.