Sensing creatinine in urine via the iontronic response of enzymatic single solid-state nanochannels.

In this study, we investigate the integration of the enzyme creatinine deiminase into solid-state nanopore walls through electrostatic assembly for the development of creatinine sensors. In these asymmetric single nanochannels, ionic transport is determined by the surface charge inside the channel, resulting in diode-like behavior that rectifies ionic current. The efficiency of such rectification depends on the surface charge density. In the presence of creatinine, the enzymatic reaction generates ammonium, leading to an increase in local pH near the channel, which can be detected through changes in transmembrane ionic transport response. Changes in rectification efficiency can be well correlated with the analyte concentration, allowing for a detection limit of 5 nM creatinine. Furthermore, this solid-state nanopore-based device is capable of sensing in diluted urine samples, showing a good linear correlation between the response and the logarithm of the creatinine concentration over a wide range of concentrations (50 nM-100 µM). These results demonstrate the potential of systems based on the integration of enzymes that induce pH changes and solid-state nanopores for the development of biomarker sensors capable of operating in complex real samples.

Relationship between Urine Serotonin and Persistent Pulmonary Hypertension of the Newborn.

Urine serotonin (5-HT)/creatinine was lower at day of life 3 in newborns with pulmonary hypertension compared with controls, while the percent change in the 5-HT metabolite, 5-hydroxyindoleacetic acid (5-HIAA)/creatinine increased. We speculate that the changes in 5-HT and 5-HIAA reflect enhanced pulmonary 5-HT uptake and/or metabolism.

Icodextrin versus Glucose 2.5% on markers of hypervolemia and survival of patients undergoing automated peritoneal dialysis with an unplanned start: a randomized controlled trial.

OBJECTIVE: The efficacy of icodextrin versus glucose patients undergoing peritoneal dialysis remains unclear. The study was designed to compare the effects of once-daily long-dwell icodextrin versus glucose on markers of hypervolemia and survival among patients with kidney failure undergoing an unplanned initiation of automated peritoneal dialysis. METHODS: This was a randomized, non-blinded, and prospective controlled study. Prevalent and stable patients undergoing automated peritoneal dialysis with a recent peritoneal equilibration test showing a dialysate/plasma creatinine of >0.50 were randomized to receive either 7.5% icodextrin or 2.5% glucose solution. Patients were evaluated at baseline (one month after the start of peritoneal dialysis), 3 months, and 6 months after inclusion. The peritoneal dialysis solution was used for at least 3 months, with a follow-up period of 24 months. RESULTS: Thirty patients were enrolled. There were no baseline differences between the groups. During the study period, patients in the Icodextrin Group showed improvements in the phase angle and ultrafiltration, whereas there were no changes in the Glucose Group. Additionally, extracellular water was significantly lower in the Icodextrin Group at the end of the study than at baseline. No statistical differences between the two groups were observed in urine volume, ultrafiltration, extracellular water, phase angle, renal creatinine clearance, use of diuretics and antihypertensives, or blood pressure. During the 24-month follow-up, the number of events related to overall mortality was seven (Icodextrin Group, n=4; Glucose Group, n=3), with no difference between the groups for this outcome or technique survival. CONCLUSION: Icodextrin significantly improved ultrafiltration, extracellular water, and phase angle at the end of the study compared to baseline in patients on the urgent start of automated peritoneal dialysis. REGISTRY OF CLINICAL TRIALS: (www.ctri.nic.in) under the number RBR-97z4wh6.

Síndrome ABCD, una causa infrecuente de hipercalcemia en pediatría / ABCD syndrome, an uncommon cause of hypercalcemia in pediatrics

El síndrome ABCD (por sus siglas en inglés, ABnormal Calcium, Calcinosis and Creatinine in Down syndrome) se caracteriza por la asociación de hipercalcemia, hipercalciuria, nefrocalcinosis y alteración de la función renal en pacientes con síndrome de Down. Existen solo 7 casos previamente publicados en el mundo, aunque se cree que está subdiagnosticado. En este reporte, presentamos 2 nuevos pacientes con este síndrome y realizamos una comparación con los casos informados hasta el momento. Si bien es una causa rara de hipercalcemia pediátrica, debe considerarse en niños con síndrome de Down una vez descartadas otras etiologías más frecuentes. Al confirmarse este diagnóstico, el tratamiento recomendado es la reducción de calcio en la dieta, trabajando de manera interdisciplinaria para mantener un aporte calórico proteico adecuado.

ABCD syndrome (ABnormal Calcium, Calcinosis, and Creatinine in Down syndrome) is characterized by an association of hypercalcemia, hypercalciuria, nephrocalcinosis, and impaired kidney function in patients with Down syndrome. Only 7 cases have been published worldwide, although it is believed to be underdiagnosed. This report describes 2 new patients with ABCD syndrome and compares them with the cases reported to date. Although it is a rare cause of pediatric hypercalcemia, it should be considered in children with Down syndrome once other more common etiologies have been ruled out. Once this diagnosis is confirmed, the recommended treatment is to reduce dietary calcium intake and work with an interdisciplinary team to maintain an adequate calorie and protein intake.

Asociación entre infusión prolongada de vancomicina yconcentración valle en niños. Estudio retrospectivo / Association between prolonged vancomycin infusion and trough concentrations in children. Retrospective study

Introducción: Este estudio investigó la concentración plasmática de vancomicina en los niños, durante la infusión prolongada. Población y métodos: Estudio retrospectivo de una cohorte que incluyó pacientes pediátricos tratados con vancomicina desde junio de 2017 hasta junio de 2020, en un hospital de referencia de nivel III. Los pacientes se dividieron en dos grupos sogún el tipo de infusión: el grupo de infusión intermitente estándar (IIE) y el grupo de infusión prolongada (IP). Se registraron detalles demográficos, periodo de infusión, creatinina plasmática, duración del tratamiento con vancomicina, concentración valle de vancomicina y permanencia en la unidad de cuidados intensivos pediátricos (UCIP). Se midieron las diferencias entre concentraciones. Resultados: Se incluyeron 68 pacientes, 31 en el grupo IIE y 37 en el grupo IP. La concentración valle de vancomicina fue significativamente más alta en el grupo IP en comparación con el grupo IIE (11,2 mg/L [5,9-13,7] vs. 7 mg/L [3,5-9,3]; p = 0,02). La tasa de logro del objetivo fue más alta en el grupo IP que en el grupo IIE (59,4 % y 19,3 % respectivamente; p = 0,001). No hubo diferencias significativas entre ambos grupos en las concentraciones pico de vancomicina, valor de creatinina final, pico de creatinina, fracaso terapéutico, duración de la estadía en la UCIP y duración del tratamiento con vancomicina. El análisis multivariado mostró que la IP se asoció en forma significativa con concentraciones valle más altas de vancomicina (OR: 2,27, p = 0,005). Conclusión: En comparación con la estrategia de IIE, la infusión prolongada puede ser una opción optimizada para los niños con infección grave, porque puede alcanzar concentraciones valle más altas y mejorar la obtención de la concentración objetivo.

Introduction: This study investigated the serum concentration of vancomycin during prolonged infusion in children. Population and methods: This retrospective cohort study included pediatric patients who received vancomycin from June 2017 to June 2020 at a tertiary referral hospital. The patients were divided into two groups according to infusion strategy, the SII (standard intermittent infusion) group and the PI (prolonged infusion) group. Demographic details, infusion period, serum creatinine, duration of vancomycin therapy, trough concentration of vancomycin, and pediatric intensive care unit stay were reviewed. Differences of the concentrations were measured. Results: Sixty-eight patients were included: 31 in the SII group and 37 in the PI group. The trough concentration of vancomycin was significantly higher in the PI group than in SII group (11.2 mg/L [5.9-13.7] vs. 7 mg/L [3.5- 9.3]; p = 0.02). The target attainment rate was higher in the PI group than in the SII group (59.4% and 19.3%, respectively; p = 0.001). There were no significant differences between the SII and PI groups regarding the peak concentrations of vancomycin, final creatinine and peak creatinine. There were no differences between the SII and PI groups regarding the failure events, PICU stay and duration of vancomycin therapy. The multivariable analysis showed that PI was significantly associated with higher trough serum concentrations of vancomycin (OR = 2.27; p = 0.005). Conclusion: Compared to the SII strategy, the PI strategy may be an optimized option to children with severe infection, as it can achieve higher trough concentrations and target concentration attainment

The urine protein/creatinine ratio as a reliable indicator of 24-h urine protein excretion across different levels of renal function and proteinuria: the TUNARI prospective study.

BACKGROUND: The 24-h urine protein (24-hUP) excretion is the gold standard for evaluating proteinuria. This study aimed to evaluate the diagnostic efficacy of protein/creatinine ratio (PCR) for estimating 24-hUP at various levels of renal function and proteinuria levels. METHODS: A cross-sectional study was conducted between December 2021 and December 2023 in Salvador, Bahia-Brazil, as an extension of previously published data from the TUNARI study. The study included 217 samples from 152 patients with various levels of renal function and proteinuria. PCR in isolated samples and 24-hUP were determined conventionally within a 24-h timeframe. Patients were classified into three groups according to the level of renal function (Group 1 = 10 to < 30 mL/min, Group 2 = 30-60 mL/min, and Group 3 = > 60 mL/min) and level of proteinuria (< 0.3 g/day, 0.3-3.5 g/day, and > 3.5 g/day). The data were analyzed using the Spearman correlation (rs), coefficient of determination (r2), Bland-Altman plots and receiver operating characteristic (ROC) curve. Likelihood ratios, positive (LR +), and negative (LR-) were derived from the sensitivity and specificity of PCR. RESULTS: Mean age was 41.5 ± 15.7 years, 61.8% were women, 36.8% Black and 52% Mixed-race. Glomerulopathies constituted 80.3%; 46.1% with lupus nephritis. Of the total urine samples, we observed a high correlation between PCR in the total sample of 24-hUP sample (rs = 0.86, p < 0.001) across different levels of renal function. However, agreement between PCR and 24-hUP was reduced at higher levels of proteinuria. The ROC analysis showed an AUC of 0.95 (95% CI = 0.92, 0.98), sensitivity of 91% and specificity of 86.5% (LR + 6.7; LR- 0.1), with an optimal cut-off of 0.77. These results were similar across renal function levels. Proteinuria ≤ 0.3 g/day showed a high sensitivity of 83.3% and specificity of 90%, with an area under (AUC) of 0.85 (95% CI = 0.71; 0.94). In the 24-hUP range > 0.3-3.5 g/day, the sensitivity was 64.1%, the specificity was 84.6%, and the AUC was 0.76 (95% CI = 0.67; 0.84), PCR detected all cases > 3.5 g/day. CONCLUSIONS: PCR is a suitable measure to be used as an indicator of 24-hUP at different levels of renal function, but may have limitations at higher levels of proteinuria. Analysis of PCR by proteinuria level found that agreement as well as sensitivity decreases at higher levels, but it maintains good specificity and is able to identify nephrotic range proteinuria.

Identification and outcomes of acute kidney disease in patients presenting in Bolivia, Brazil, South Africa, and Nepal.

BACKGROUND: The International Society of Nephrology proposes an acute kidney disease (AKD) management strategy that includes a risk score to aid AKD identification in low- and low-middle-income countries (LLMICs). We investigated the performance of the risk score and determined kidney and patient outcomes from AKD at multiple LLMIC sites. METHODS AND FINDINGS: Adult patients presenting to healthcare facilities in Bolivia, Brazil, South Africa, and Nepal were screened using a symptom-based risk score and clinical judgment. Those at AKD risk underwent serum creatinine testing, predominantly with a point-of-care (POC) device. Clinical data were collected prospectively between September 2018 and November 2020. We analyzed risk score performance and determined AKD outcomes at discharge and over follow-up of 90 days. A total of 4,311 patients were at increased risk of AKD, and 2,922 (67.8%) had AKD confirmed. AKD prevalence was 80.2% in patients enrolled based on the risk score and 32.5% when enrolled on clinical judgment alone (p < 0.0001). The area under the receiver operating characteristic curve was 0.73 for the risk score to detect AKD. Death during admission occurred in 84 (2.9%) patients with AKD and 3 (0.2%) patients without kidney disease (p < 0.0001). Death after discharge occurred in 206 (9.7%) AKD patients, and 1865 AKD patients underwent reassessment of kidney function after discharge; 902 (48.4%) patients had persistent kidney disease including 740 (39.7%) patients reclassified with de novo or previously undiagnosed chronic kidney disease (CKD). The study was pragmatically designed to assess outcomes as part of routine healthcare, and there was heterogeneity in clinical practice and outcomes between sites, in addition to selection bias during cohort identification. CONCLUSIONS: The use of a risk score can aid AKD identification in LLMICs. High rates of persistent kidney disease and mortality after discharge highlight the importance of AKD follow-up in low-resource settings.

Urine epidermal growth factor as a biomarker for kidney function recovery and prognosis in glomerulonephritis with severe kidney function impairment.

BACKGROUND: Prognostication in glomerulonephritis with severe kidney function impairment is critical for evaluating the benefit-to-risk ratio of immunosuppression. We hypothesized that the urine biomarker epidermal growth factor (EGF) could have good discrimination power to identify subjects who might ultimately recover kidney function. METHODS: We included 82 subjects with glomerulonephritis and severe kidney function impairment at admission (estimated glomerular filtration rate [eGFR] ≤ 30 mL/min/1.73m2): 58 with lupus nephritis (LN) and 24 with ANCA-associated vasculitis (AAV). Thirty-five subjects required kidney replacement therapy (KRT) at presentation. Urine epidermal growth factor was measured and corrected by urine creatinine (uEGF/Cr) and the population was analyzed by uEGF/Cr tertiles. The primary outcome was time to recovery of eGFR ≥ 30 mL/min/1.73m2 and time to recovery of kidney function with dialysis independence in those with initial KRT. RESULTS: Forty-four (54%) participants met the primary outcome of recovery of eGFR ≥ 30 mL/min/1.73m2. The 6-month recovery rates were 93%, 57%, and 0% for participants in the highest, middle, and lowest uEGF/Cr tertile, respectively. Recovery of the kidney function was faster and led to a higher post-therapy eGFR in the highest uEGF/Cr tertile. In the ROC analysis, uEGF/Cr was a predictor of recovery with an area under the curve (AUC) of 0.92 (95% CI 0.87-0.98), and a cutoff of 2.60 ng/mg had 100% sensitivity to detect patients who recovered kidney function. In the subgroup of participants with initial KRT, the cut-off of uEGF/Cr of 2.0 ng/mg had 100% sensitivity to detect participants who recovered kidney function with dialysis independence by 6 months. CONCLUSIONS: Urine EGF/Cr is a promising biomarker to aid in the prediction of recovery of kidney function in glomerulonephritis with severe kidney function impairment.

Integration of paper-based analytical devices with digital microfluidics for colorimetric detection of creatinine.

Digital microfluidics (DMF) is a platform that enables the automated manipulation of individual droplets of sizes ranging from nanoliter to microliter and can be coupled with numerous techniques, including colorimetry. However, although the DMF electrode architecture is highly versatile, its integration with different analytical methods often requires either changes in sample access, top plate design, or the integration of supplementary equipment into the system. As an alternative to overcome these challenges, this study proposes a simple integration between paper-based analytical devices (PADs) and DMF for automated and eco-friendly sample processing aiming at the colorimetric detection of creatinine (CR, an important biomarker for kidney disease) in artificial urine. An optimized and selective Jaffé reaction was performed on the device, and the reaction products were delivered to the PAD, which was subsequently analyzed with a bench scanner. The optimal operational parameters on the DMF platform were a reaction time of 45 s with circular mixing and image capture after 5 min. Under optimized conditions, a linear behavior was obtained for creatinine concentrations ranging from 2 to 32 mg dL-1, with limits of detection and quantitation equal to 1.4 mg dL-1 and 2.0 mg dL-1, respectively. For the concentration range tested, the relative standard deviation varied from 2.5 to 11.0%, considering four measurements per concentration. CR-spiked synthetic urine samples were subjected to analysis via DMF-PAD and the spectrophotometric reference method. The concentrations of CR determined using both analytical techniques were close to the theoretical values, with the resultant standard deviations of 2-9% and 1-4% for DMF-PADs and spectrophotometry, respectively. Furthermore, the recovery values were within the acceptable range, with DMF-PADs yielding 96-108% and spectrophotometry producing 95-102%. Finally, the greenness of the DMF-PAD and spectrophotometry methods was evaluated using the Analytical Greenness (AGREE) metric software, in which 0.71 and 0.51 scores were obtained, respectively. This indicates that the proposed method presents a higher greenness level, mainly due to its miniaturized characteristics using a smaller volume of reagent and sample and the possibility of automation, thus reducing user exposure to potentially toxic substances. Therefore, the DMF-PADs demonstrated great potential for application in the clinical analysis of creatinine, aiding in routine tests by introducing an automated, simple, and environmentally friendly process.

Renal protective potential of pentoxifylline, chlorpromazine, and lovastatin in ischemia-reperfusion injury: An experimental study.

This study aimed to evaluate the ability of pentoxifylline when compared to lovastatin and chlorpromazine as nephroprotective substances in cases of renal ischemia and reperfusion syndrome (IRI). A total of 36 adult male animals were randomly allocated into four groups (untreated control group, pentoxifylline group, lovastatin group, and chlorpromazine group), each consisting of nine animals. All groups were submitted to experimental ischemia and reperfusion procedures. The animals were evaluated 24, 72 and 120 hours after IRI, including physical examinations, serum urea and creatinine measurements, as well as histopathological, morphometric, and stereological analyses of the renal tissue. Results indicated that 24 hours after IRI, only chlorpromazine was effective in controlling azotemia. At the 72-hour mark, both chlorpromazine and pentoxifylline exhibited efficacy. After 120 hours, all three substances demonstrated renal protective qualities. Pentoxifylline was the most effective in preserving the structural integrity of kidney tissue, followed by chlorpromazine. In conclusion, all three treatments (pentoxifylline, chlorpromazine, and lovastatin) were effective. Pentoxifylline proved to be promising in the response against acute tubular necrosis, although chlorpromazine presented earlier renoprotective effects in terms of maintaining renal function.

Clinical response to nonsurgical periodontal therapy is associated with decreased serum leukocyte count and uric acid levels in kidney transplant recipients.

OBJECTIVE: This study sought to investigate the relationship between clinical response to nonsurgical periodontal therapy (NSPT) and serum changes in leukocyte count, fasting blood glucose, hemoglobin, hematocrit, creatinine, and uric acid in kidney transplant recipients (KTR). METHODOLOGY: A prospective study was performed on 20 KTRs. Periodontal and serum data were collected before and 90 days after NSPT, and delta values (Δ = after NSPT - before) were calculated. Periodontal assessment included periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP). Patients were classified based on the presence of periodontitis and then categorized into stages. RESULTS: Patients showed a reduction in the percentage of sites with PPD≥3mm, PPD≥4 mm and BOP, after NSPT. There was a direct correlation between the deltas of leukocyte count and CAL ≥3 mm (r=0.645, P=0.002) and BOP (r=0.663, P=0.001), and the deltas of uric acid and CAL ≥3 mm (r=0.562, P=0.010). CONCLUSION: A good clinical response to NSPT may affect the reduction of serum levels of leukocyte count and uric acid, suggesting a beneficial effect on systemic health in KTR.

[Decline in Renal Function with Age in Chile: Gender Differences and the Impact of Comorbidities]. / Disminución de la función renal con la edad en Chile: Diferencias de género y efecto de comorbilidades.

The estimated glomerular filtration rate (eGFR) using serum creatinine is widely utilized for assessing renal function. Its decrease with age and in the presence of chronic diseases such as diabetes, hypertension, and obesity is well-known. However, there are no representative data for the Chilean population. AIM: To estimate the decline in eGFR with age according to gender and the presence of chronic diseases in the adult Chilean population. METHODS: This cross-sectional study involved 5,638 participants aged ≥18 years from the National Health Survey 2009 and 2017. The eGFR was estimated using the CKD-EPI formula based on serum creatinine. The decline in eGFR was compared by gender and the presence of chronic diseases (diabetes, hypertension, dyslipidemia, and/or obesity). RESULTS: eGFR declined with age in both genders, with a steeper decrease in women (-0.88 vs. -0.78 mL/min/1.73 m2/year, p<0.01). The decline in eGFR started early and uniformly from the age of 18. In the presence of chronic diseases, the slope was significantly steeper (-0.94 vs. -0.83 mL/min/1.73 m2/ year, p<0.001), with women with chronic diseases experiencing the greatest decline (-1.00 mL/min/1.73 m2/year). CONCLUSION: eGFR progressively decreased with age in the Chilean population, showing an early decline starting from 18 years, more pronounced in women, and in the presence of chronic diseases. Our findings provide relevant population-based information for interpreting eGFR across different age groups and risk categories.

Kidney replacement therapy in COVID-19-Related acute kidney injury: The impact of timing on mortality.

The objective of this study was to determine the impact of the timing of KRT, dichotomized by a temporal criterion or by creatinine level, in patients with COVID-19-related AKI. This was a retrospective study involving 512 adult patients admitted to the ICU. All participants had laboratory-confirmed COVID-19 and a confirmed diagnosis of AKI. The potential predictors were the determination of the timing of KRT based on a temporal criterion (days since hospital admission) and that based on a serum creatinine cutoff criterion. Covariates included age, sex, and the SOFA score, as well as the need for mechanical ventilation and vasopressors. The main outcome measure was in-hospital mortality. We evaluated 512 patients, of whom 69.1% were men. The median age was 64 years. Of the 512 patients, 76.6% required dialysis after admission. The overall in-hospital mortality rate was 72.5%. When the timing of KRT was determined by the temporal criterion, the risk of in-hospital mortality was significantly higher for later KRT than for earlier KRT-84% higher in the univariate analysis (OR = 1.84, 95%, [CI]: 1.10-3.09) and 140% higher after adjustment for age, sex, and SOFA score (OR = 2.40, 95% CI: 1.36-4.24). When it was determined by the creatinine cutoff criterion, there was no such difference between high and low creatinine at KRT initiation. In patients with COVID-19-related AKI, earlier KRT might be associated with lower in-hospital mortality.

Nephroprotective effects of hyperbaric oxygen therapy in murine models of acute kidney injury: A systematic review and meta-analysis.

AIMS: Acute kidney injury (AKI) is a life-threatening condition marked by sudden kidney function loss and azotemia. While its management is limited to supportive care, the effects of hyperbaric oxygen therapy (HBO) on AKI remain a subject of conflicting animal research. This study aimed to systematically review and meta-analyze HBO's effects on renal function biomarkers serum creatinine (SCr) and blood urea nitrogen (BUN) in murine AKI models, also exploring tissue-level nephroprotection. MAIN METHODS: The PUBMED, SciELO, and LILACS databases were searched until September 5, 2024. Effect sizes of HBO on SCr and BUN levels were expressed as standardized mean difference (SMD) alongside 95 % confidence interval (CI), calculated by random-effects model. Extracted data also included murine specie/strain, HBO parameters, AKI induction method (toxic, ischemic, others), and histological findings. Study quality and publication bias were respectively assessed using the CAMARADES checklist and Egger's test. This review adhered to PRISMA guidelines and was registered in PROSPERO (CRD42022369804). KEY FINDINGS: Data synthesis from 21 studies demonstrates that HBO effectively reduces azotemia in AKI-affected animals (SCr's SMD = -1.69, 95 % CI = -2.38 to -0.99, P < 0.001; BUN's SMD = -1.51, 95 % CI = -2.32 to -0.71, P < 0.001) while mitigating histological damage. Subgroup analyses indicate that HBO particularly benefits ischemic and other AKI types (P < 0.05). In contrast, data from toxic AKI models were inconclusive due to insufficient statistical power (P > 0.05, 1-ß < 30 %). SIGNIFICANCE: This meta-analysis provides compelling evidence supporting the adjunctive use of HBO in AKI management.

Effect of creatine supplementation on muscular function and physical performance in children and adolescents a literature review / Efecto de la suplementación de creatina en la función muscular y rendimiento físico en niños y adolescentes una revisión de la literatura

Introduction: Creatine (Cr) is an effective and safe ergogenic supplement that enhances post-exercise recovery, prevents injuries, supports thermoregulation, and provides benefits in rehabilitation, as well as spinal and cerebral neuroprotection for adults and older individuals. However, the evidence regarding its benefits in the pediatric population across various contexts has not been conclusive. Objective: Analyze the impact of different doses of Cr on physical performance and muscle function in children and adolescents in general through a systematic review of the literature. Materials and methods: This review followed the PRISMA reporting guidelines in the electronic databases of PubMed/Medline and Google Scholar. It included controlled clinical trials conducted between 1997 and May 2023 that assessed the effect of Cr supplementation on muscle function and physical performance in children and adolescents. A total of 20 studies were included. Results: The subjects included young high-performance athletes from different disciplines and children or adolescents diagnosed with pathologies affecting muscle function. Significant effects were found in athletes' physical performance and muscular function at various doses and periods of supplementation, unlike those involving a pathology, which mainly did not present improvements in these variables. Conclusions: Some reports suggest a positive effect on physical performance, specifically in young athletes. However, the Cr doses, posology, and administration protocols vary between studies(AU)

Introducción: La creatina (Cr) es un suplemento ergogénico eficaz y seguro que mejora la recuperación post-ejercicio, previene lesiones, favorece la termorregulación y proporciona beneficios en la rehabilitación, así como neuro protección tanto espinal como cerebral para adultos y personas mayores. No obstante, la evidencia sobre sus beneficios en la población pediátrica en diversos contextos aún no ha sido concluyente. Objetivo: Analizar el impacto de diferentes dosis de Cr sobre el rendimiento físico y la función muscular en niños y adolescentes de forma general mediante una revisión sistemática de la literatura. Materiales y métodos: Esta revisión se llevó a cabo mediante la pauta del informe PRISMA en las bases de datos electrónicas de PubMed/Medline y Google Scholar, se incluyeron ensayos clínicos controlados realizados entre 1997 y mayo de 2023 que evaluaron el efecto de la suplementación con Cr en niños y adolescentes sobre la función muscular y el rendimiento físico. Se incluyeron un total de 20 estudios. Resultados: Los sujetos incluyeron jóvenes deportistas de alto rendimiento de diferentes disciplinas y niños o adolescentes diagnosticados con algunas patologías que afectan la función muscular. Se encontraron efectos significativos en el rendimiento físico y la función muscular de los deportistas con diferentes dosis y periodos de suplementación, a diferencia de aquellos que involucran una patología que en su mayoría no presentaron mejoras en estas variables. Conclusiones: Algunos informes sugieren un efecto positivo en el rendimiento físico, especialmente en jóvenes atletas. Sin embargo, las dosis de creatina, así como los regímenes de dosificación y los protocolos de administración, varían entre los estudios(AU)

Renal Functional Reserve in Naïve HIV Patients.

Introduction. Renal functional reserve (RFR) is the kidney capability of increasing its basal glomerular filtration rate (GFR) at least 20% after an adequate stimulus. Renal disorders have been reported in seropositive HIV patients, particularly the decrease in glomerular filtration rate (eGFR), nephrotic syndrome, and proximal tubular deficiency associated with the disease itself or the use of some anti-retroviral treatments. Thus, it was decided to carry out a prospective study in order to evaluate if RFR test was preserved in naive HIV patients. Material and Method. GFR was measured by using cimetidine-aided creatinine clearance (CACC), and RFR as described Hellerstein et al. in seropositive naive HIV patients and healthy volunteers. Results. RFR was evaluated in 12 naïve HIV patients who showed positive RFR (24.8±2%), but significantly lower compared to RFR in 9 control individuals (90.3 ± 5%). Conclusion. In this study was found that renal functional reserve was positive in naïve HIV patients, but significantly lower compared to renal functional reserve achieved by seronegative healthy individuals.

Investigating artificial intelligence models for predicting joint pain from serum biochemistry.

OBJECTIVE: The study used machine learning models to predict the clinical outcome with various attributes or when the models chose features based on their algorithms. METHODS: Patients who presented to an orthopedic outpatient department with joint swelling or myalgia were included in the study. A proforma collected clinical information on age, gender, uric acid, C-reactive protein, and complete blood count/liver function test/renal function test parameters. Machine learning decision models (Random Forest and Gradient Boosted) were evaluated with the selected features/attributes. To categorize input data into outputs of indications of joint discomfort, multilayer perceptron and radial basis function-neural networks were used. RESULTS: The random forest decision model outperformed with 97% accuracy and minimum errors to anticipate joint pain from input attributes. For predicted classifications, the multilayer perceptron fared better with an accuracy of 98% as compared to the radial basis function. Multilayer perceptron achieved the following normalized relevance: 100% (uric acid), 10.3% (creatinine), 9.8% (AST), 5.4% (lymphocytes), and 5% (C-reactive protein) for having joint pain. Uric acid has the highest normalized relevance for predicting joint pain. CONCLUSION: The earliest artificial intelligence-based detection of joint pain will aid in the prevention of more serious orthopedic complications.

Association of uric acid with body adiposity and biochemical parameters in kidney transplant patients.

BACKGROUND: Obesity and various biochemical parameters, including triglycerides, cholesterol, glucose, C-reactive protein, and estimated glomerular filtration rate, have been linked to elevated uric acid (UA) levels in populations with normal kidney function due to decreased UA excretion and/or increased UA synthesis. However, it remains unclear whether all these factors exhibit similar associations with UA levels in clinical populations characterized by compromised renal function, such as kidney transplant patients (KTPs). OBJECTIVE: To evaluate whether serum UA levels are associated with body adiposity and biochemical parameters in KTPs. METHODS: A cross-sectional study involving 113 KTPs was conducted. Body fat was estimated using bioelectrical impedance, and waist circumference was measured using an inelastic tape. Serum levels of UA, creatinine, glucose, triglycerides, total cholesterol, and its fractions were measured using the colorimetric method. C-reactive protein levels were assessed using the immunoturbidimetric method, and urea levels were determined via enzymatic kinetics. Glomerular filtration rate was estimated using the chronic kidney disease epidemiology collaboration equation. Linear regression analyses were employed to assess the association between serum UA levels and body adiposity as well as biochemical parameters, while adjusting for confounders. RESULTS: Serum UA levels exhibited a positive association with creatinine (ß = 0.402; p = 0.013) and urea (ß = 0.024; p = 0.001), while demonstrating an inverse association with estimated glomerular filtration rate (ß = -0.030; p < 0.001). However, serum UA levels were not significantly associated with fat mass (both in kilograms and as a percentage), waist circumference, triglycerides, C-reactive protein, glucose, HDL cholesterol, LDL cholesterol, VLDL cholesterol, or total cholesterol. CONCLUSION: Serum UA levels are only associated with biochemical parameters linked to renal function in KTPs. Consequently, in individuals with suboptimal renal function, such as KTPs, UA does not exhibit associations with other biochemical parameters and body adiposity, as commonly observed in non-renal disease populations.

Redefining urine output thresholds for acute kidney injury criteria in critically Ill patients: a derivation and validation study.

INTRODUCTION: The current definition of acute kidney injury (AKI) includes increased serum creatinine (sCr) concentration and decreased urinary output (UO). Recent studies suggest that the standard UO threshold of 0.5 ml/kg/h may be suboptimal. This study aimed to develop and validate a novel UO-based AKI classification system that improves mortality prediction and patient stratification. METHODS: Data were obtained from the MIMIC-IV and eICU databases. The development process included (1) evaluating UO as a continuous variable over 3-, 6-, 12-, and 24-h periods; (2) identifying 3 optimal UO cutoff points for each time window (stages 1, 2, and 3); (3) comparing sensitivity and specificity to develop a unified staging system; (4) assessing average versus persistent reduced UO hourly; (5) comparing the new UO-AKI system to the KDIGO UO-AKI system; (6) integrating sCr criteria with both systems and comparing them; and (7) validating the new classification with an independent cohort. In all these steps, the outcome was hospital mortality. Another analyzed outcome was 90-day mortality. The analyses included ROC curve analysis, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and logistic and Cox regression analyses. RESULTS: From the MIMIC-IV database, 35,845 patients were included in the development cohort. After comparing the sensitivity and specificity of 12 different lowest UO thresholds across four time frames, 3 cutoff points were selected to compose the proposed UO-AKI classification: stage 1 (0.2-0.3 mL/kg/h), stage 2 (0.1-0.2 mL/kg/h), and stage 3 (< 0.1 mL/kg/h) over 6 h. The proposed classification had better discrimination when the average was used than when the persistent method was used. The adjusted odds ratio demonstrated a significant stepwise increase in hospital mortality with advancing UO-AKI stage. The proposed classification combined or not with the sCr criterion outperformed the KDIGO criteria in terms of predictive accuracy-AUC-ROC 0.75 (0.74-0.76) vs. 0.69 (0.68-0.70); NRI: 25.4% (95% CI: 23.3-27.6); and IDI: 4.0% (95% CI: 3.6-4.5). External validation with the eICU database confirmed the superior performance of the new classification system. CONCLUSION: The proposed UO-AKI classification enhances mortality prediction and patient stratification in critically ill patients, offering a more accurate and practical approach than the current KDIGO criteria.

Weak association between urea-creatinine ratio and c-reactive protein with nutritional risk in hospitalized patients with COVID-19: A cross-sectional study.

BACKGROUND: COVID-19 is a systemic infection with a significant impact on nutrition risk and the hematopoietic system. The neutrophil-lymphocyte ratio (NLR) may have prognostic value in determining severe cases of COVID-19 and the urea-creatinine ratio (UCR) is currently being studied as a potential biomarker of catabolism associated with critical illness. The aim was to assess the association between the NLR, UCR and C-reactive protein (CRP) with nutritional risk in hospitalized patients with COVID-19. METHODS: This is a retrospective cross-sectional study that assessed 589 hospitalized patients with COVID-19, 18 years of age or older, of both sexes. Nutritional risk was assessed by Nutritional Risk Screening (NRS, 2002) and NLR by neutrophils divided by lymphocyte count. The UCR was calculated by the ratio between urea and creatinine and quantified by the calorimetric biochemical method and CRP by the immunoturbidimetric method. Differences between groups were applied by the Mann-Whitney U test and the automated binary regression test. RESULTS: Of the 589 patients, 87.4% were at nutritional risk. When evaluating patients admitted to the ICU, 91.9% were at nutritional risk. Patients with NRS ≥3 are older, with lower body mass and BMI, higher NLR and UCR and lower CRP values. However, 73% of patients admitted to the ward were at nutritional risk, and only age differed between groups, being higher in patients with NRS ≥3. Logistic regression showed a weak association between nutritional risk in NRS and UCR (Model 1) (OR = 0.96, 95%CI: 0.94-0.99, p = 0.003) and NRS with CRP (Model 1) (OR = 1.01, 95%CI: 1.00-1.02, p < 0.001) in patients in the ICU. On the other hand, the logistic regression in ward patients found association only for CRP in both models (Model 1, OR = 1.01, 95%CI: 1.00-1.01, p = 0.041) and (Model 2, OR = 1.01, 95%CI: 1.00-1.01, p = 0.031). CONCLUSION: We found a weak association between nutritional risk and UCR and CRP levels in patients admitted to the ICU, while in the ward patients the nutritional risk also had weak association with CRP.