Relación de la hiperuricemia con las alteraciones metabólicas y factores de riesgo cardiovascular en jóvenes mexicanos.

INTRODUCTION: Hyperuricemia is a risk factor for cardiovascular disease, but its impact has not been properly documented. OBJECTIVE: To assess the impact of hyperuricemia on metabolic parameters and cardiovascular risk factors (CRF) in apparently healthy Mexicans. METHOD: Cross-sectional study of 768 young adults. Association of hyperuricemia with alterations in metabolic parameters and CRF (hypertension, mixed dyslipidemia, metabolic syndrome) was sought. Log-linear and regression models were used to determine the influence of hyperuricemia. A multivariate analysis of variance was applied to observe the interaction of hyperuricemia and overweight or obesity with changes in metabolic parameters. RESULTS: Metabolic parameters were higher in patients with hyperuricemia than with normal uric acid (all < 0.05). Hyperuricemia was significantly associated with hypertension (OR=6.8, 95 % CI: 1.1-46), dyslipidemia (OR=2.5, 95% CI: 1.3-4.7) and metabolic syndrome (OR=2.3, 95% CI: 1.1-4.6). Hyperuricemia and overweight or obesity significantly predict changes in cardiovascular risk metabolic parameters (Wilks' l=0.91, F (6.175)=3.1, p=0.007). CONCLUSIONS: Hyperuricemia is significantly associated with metabolic alterations and different CRF.

INTRODUCCIÓN: La hiperuricemia es un factor de riesgo para enfermedad cardiovascular, pero su impacto no ha sido bien documentado. OBJETIVO: Evaluar el impacto de la hiperuricemia en los parámetros metabólicos y los factores de riesgo cardiovascular en mexicanos aparentemente sanos. MÉTODO: Estudio trasversal de 768 adultos jóvenes. Se buscó asociación de la hiperuricemia con alteraciones de los parámetros metabólicos y factores de riesgo cardiovascular (hipertensión, dislipidemia mixta y síndrome metabólico). Se aplicaron modelos loglineales y de regresión para determinar la influencia de la hiperuricemia. Se aplicó análisis multivariado de varianza para observar la interacción de la hiperuricemia y el sobrepeso u obesidad en los cambios de los parámetros metabólicos. RESULTADOS: Los parámetros metabólicos fueron mayores en los individuos con hiperuricemia que con ácido úrico normal (< 0.05). La hiperuricemia se asoció significativamente con hipertensión (RM = 6.8, IC 95 % = 1.1-46), dislipidemia (RM = 2.5, IC 95 % = 1.3-4.7) y síndrome metabólico (RM = 2.3, IC 95 % = 1.1-4.6). La hiperuricemia y el sobrepeso u obesidad predicen significativamente los cambios en los parámetros metabólicos de riesgo cardiovascular (l de Wilks = 0.91, F [6.175] = 3.1, p = 0.007). CONCLUSIONES: La hiperuricemia está asociada significativamente con las alteraciones metabólicas y los distintos factores de riesgo cardiovascular.

Ácido úrico sérico como marcador de gravedad clínica y comorbilidad en psoriasis en placas.

INTRODUCCIÓN: La hiperuricemia es común en pacientes con psoriasis. Se ha sugerido que la elevación de ácido úrico en psoriasis está fuertemente asociada con morbilidad cardiovascular. OBJETIVO: Determinar la relación entre niveles de ácido úrico, gravedad clínica medida por Psoriasis Area Severity Index (PASI), Body Surface Area (BSA) y static Physician's Global Assessment (sPGA) en pacientes con psoriasis en placas y comorbilidades ungueales y artritis psoriásica. MÉTODO: Determinación de ácido úrico sérico en 45 pacientes con psoriasis en placas y 45 controles pareados por sexo, edad e índice de masa corporal; medición de índices de gravedad clínica en pacientes y presencia de manifestaciones ungueales y articulares. RESULTADOS: Los pacientes con psoriasis presentaron niveles más elevados de ácido úrico (7.03 ± 1.47 versus 5.32 ± 1.17, p < 0.01) y mayor prevalencia de hiperuricemia asintomática (68 versus 17.8 %, p < 0.01) que los controles. Existió correlación proporcional significativa entre gravedad determinada por PASI y ácido úrico (r2 = 0.70) y entre manifestaciones articulares e hiperuricemia en pacientes con psoriasis en placas (p < 0.01; RM = 2.85, IC 95 % = 1.52-5.33). CONCLUSIONES: Los niveles séricos de ácido úrico tuvieron correlación proporcional con PASI y se asociaron con manifestaciones articulares en pacientes con psoriasis en placas. INTRODUCTION: Hyperuricemia is common in patients with psoriasis. Uric acid elevation in psoriasis has been suggested to be strongly associated with cardiovascular morbidity. OBJECTIVE: To determine the relationship between uric acid levels and clinical severity as measured by the Psoriasis Area Severity Index (PASI), body surface area (BSA) and static Physician's Global Assessment (sPGA) in patients with plaque psoriasis and nail comorbidities and psoriatic arthritis. METHOD: Determination of serum uric acid in 45 patients with plaque psoriasis and 45 controls matched by gender, age and body mass index; measurement of patient clinical severity indices and presence of nail and joint manifestations. RESULTS: Patients with psoriasis had higher levels of uric acid (7.03 ± 1.47 versus 5.32 ± 1.17, p < 0.01), and higher prevalence of asymptomatic hyperuricemia than controls (68% versus 17.8%, p < 0.01). There was significant proportional correlation between PASI-determined severity and uric acid (r2 = 0.70), and between joint manifestations and hyperuricemia in patients with plaque psoriasis (p < 0.01; OR = 2.85, 95% CI = 1.52-5.33). CONCLUSIONS: Serum uric acid levels had a proportional correlation with PASI and were associated with joint manifestations in patients with plaque psoriasis.

[Hyperuricaemia and metabolic syndrome in obese children and adolescents]. / Hiperuricemia y componentes del síndrome metabólico en niños y adolescentes obesos.

INTRODUCTION: Hyperuricaemia has been suggested as an additional metabolic factor in adult obese patients, but it has not been sufficiently studied in paediatric. OBJECTIVES: To assess the relationship between serum uric acid levels (SUAL) with the level of general and visceral obesity, and other biochemical parameters in children and adolescents of Santiago, Chile. SUBJECTS AND METHOD: A cross sectional study was conducted on 770 children and adolescents (ages: 6-15 y.) from a public school in Santiago, Chile, of whom 227 (29%) were obese (BMI>2 SD, WHO growth standards). Ninety subjects were randomly selected and 77 with no other chronic disease (41 males) accepted to participate. Data was collected on weight, stature, abdominal circumference (AC), visceral adiposity using ultrasound, and other biochemical measurements including fasting glucose, insulin, serum lipids, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and SUAL. RESULTS: The mean SUAL was 0.200±0.065 mmol/L, and was increased in children with hyperinsulinism (adjusted by age: 0.221±0.075 vs. 0.183±0.054 mmol/L; P<.01), with no significant differences according to HOMA. Differences were also found between children with ALT>or<26 U/mL: 0.238±0.070 vs. 0.178±0.054 mmol/L, P<.001. The logistic regression showed the increased SUAL was only associated with increased ALT. No significant differences were found in general or visceral adiposity measurements or fatty liver. CONCLUSIONS: Children and adolescents from Santiago, Chile have higher uric acid serum uric acid levels as well as an association with increased ALT and insulin. It is demonstrated in this study that uric acid should be measured in obese children and adolescents, and in their follow up.

Usefulness of dual-energy computed tomography with and without dedicated software in identifying uric acid kidney stones.

OBJECTIVE: To prospectively evaluate the usefulness of dual-energy computed tomography (DECT) with and without dedicated software in identifying uric acid kidney stones in vivo. MATERIAL AND METHODS: We studied 65 kidney stones in 63 patients. All stones were analyzed in vivo by DECT and ex vivo by spectrophotometry. We evaluated the diagnostic performance in identifying uric acid stones with DECT by analyzing the radiologic densities with dedicated software and without using it (through manual measurements) as well as by analyzing the attenuation ratios of the stones in both energies with and without the dedicated software. RESULTS: The six uric acid stones included were correctly identified by evaluating the attenuation ratios with a cutoff of 1.21, both with the dedicated software and without it, yielding perfect diagnostic performance without false positives or false negatives. The study of the attenuations of the stones obtained the following values on the receiver operating characteristic curves in the classification of the uric acid stones: 0.92 for the measurements done with the software and 0.89 for the manual measurements; a cutoff of 538 HU yielded 84% (42/50) diagnostic accuracy for the software and 83.1% (54/65) for the manual measurements. CONCLUSIONS: DECT enabled the uric acid stones to be identified correctly through the calculation of the ratio of the attenuations in the two energies. The results obtained with the dedicated software were similar to those obtained manually.

Assessing levels of uric acid and other cardiovascular markers in prehypertensive and hypertensive adults.

INTRODUCTION: Although some studies have reported the association between uric acid (UA) and hypertension, evidence on prehypertension is still lacking. Therefore, the objective of this study was to determine the levels of UA and other cardiovascular markers among prehypertensive and hypertensive patients and assess their risk for developing arterial hypertension. METHODS: 157 individuals were recruited: 67 normotensive, 23 pre-hypertensive and 67 hypertensive. Blood samples were collected to measure biochemical parameters and anthropometric measurements and blood pressure were evaluated. We calculated the product of lipid accumulation and the visceral adiposity index to assess cardiovascular risk. RESULTS: Our data showed an increase in UA levels in normotensives (4.9±1.3mg/dL), prehypertensives (5.2±1.3mg/dL) and hypertensives (5.9±1.6mg/dL) (p=0.004). We found a higher frequency of hyperuricemia in the hypertensive group (34.3%) than in the normotensive group (13.4%, p<0.05). Hypertensive volunteers had lower levels of HDL-C (p=0.004 and p=0.003) and higher body mass indexes (p<0.001 and p=0.007), glucose (p<0.001 and p=0.033), triglycerides (p=0.001 and p=0.005), visceral adiposity index (p<0.001 and p=0.002) and lipid accumulation product (p<0.001 and p=0.007) than normotensive and prehypertensive participants. We also observed that individuals with UA≥6.2mg/dL had an increased risk of hypertension of 4.77 (p=0.003) compared to individuals with levels≤4.3mg/dL. CONCLUSION: Our results showed that UA is associated with increased blood pressure and unfavorable changes in anthropometric and biochemical parameters, which represent risk factors for hypertension and cardiovascular diseases.

[Gout, beyond the joint: How should we treat it?] / La gota, más allá de la articulación: ¿cómo debemos tratarla?

Gout is a disease caused by the chronic deposition of monosodium urate crystals. Its clinical presentation as an acute, self-limiting arthritis and the belief that it is a banal, self-inflicted disease have led to its poor management. Despite advances in the knowledge of the disease and the simplicity of its management, no more than 30% of patients are well treated. In Spain, the prevalence of gout is 2.5% and its incidence is increasing. In the following article we will review the pathogenesis of gout and hyperuricaemia, highlighting the greater weight of genetics and renal function over diet. We will look at the consequences of crystal deposition. Gout, in addition to its joint presentation and renal involvement, has been shown to be an independent cardiovascular risk factor. Hypouricemic therapy is the most important treatment, as it is the one that dissolves the crystals and cures the disease. This requires the sustained achievement of uricemia levels below 6mg/dl. We will also review preventive and flares treatment, as well as the role of patient education in terms of both lifestyle and dietary habits and adherence to pharmacological treatment.

Pharmacologic treatment of kidney stones: Current medication and pH monitoring.

Nephrolithiasis is a globally prevalent urologic condition associated with significant morbidity and patient discomfort. Current management of kidney stones includes both surgical and pharmacologic interventions. Though surgery may be necessary under certain circumstances, pharmacologic treatment is a more affordable, readily available, and a less invasive option for patients. A comprehensive scoping review was conducted to summarize the available literature on the pharmacologic strategies for managing the predominant stone types including calcium oxalate, calcium phosphate, uric acid, struvite, and cystine stones. Central to these therapeutic approaches is the regulation of factors such as urine pH, stone crystallization, and patient metabolics that precipitate stone development and growth. This review highlights the pharmacological options available for treating each kidney stone type, emphasizing the importance of patient tailored medical management that should be considered by every physician.

Uric acid and acute kidney injury in high-risk patients for developing acute kidney injury undergoing cardiac surgery: A prospective multicenter study.

PURPOSE: It is unclear whether preoperative serum uric acid (SUA) elevation may play a role in the development of acute kidney injury (AKI) associated with cardiac surgery (CSA-AKI). We conducted a cohort study to evaluate the influence of preoperative hyperuricemia on AKI in patients at high risk for developing SC-AKI. DESIGN: Multicenter prospective international cohort study. SETTING: Fourteen university hospitals in Spain and the United Kingdom. PARTICIPANTS: We studied 261 consecutive patients at high risk of developing CSA-AKI, according to a Cleveland score ≥ 4 points, from July to December 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: AKIN criteria were used for the definition of AKI. Multivariable logistic regression models and propensity score-matched pairwise analysis were used to determine the adjusted association between preoperative hyperuricemia (≥7 mg/dL) and AKI. Elevated preoperative AUS (≥7 mg/dL) was present in 190 patients (72.8%), whereas CSA-AKI occurred in 145 patients (55.5%). In multivariable logistic regression models, hyperuricemia was not associated with a significantly increased risk of AKI (adjusted Odds Ratio [OR]: 1.58; 95% confidence interval [CI]: 0.81-3; P = .17). In propensity score-matched analysis of 140 patients, the hyperuricemia group experienced similar adjusted odds of AKI (OR 1.05, 95%CI 0.93-1.19, P = .37). CONCLUSIONS: Hyperuricemia was not associated with an increased risk of AKI in this cohort of patients undergoing cardiac surgery at high risk of developing CSA-AKI.

[Correlation of uric acid with carotid intima media thickness in obese adolescents]. / Correlación del ácido úrico con el grosor de la íntima media de la carótida en adolescentes con obesidad.

Introduction: Introduction: obesity in the pediatric population is a public health problem. The correlation of uric acid and carotid intima media thickness in adults has been demonstrated. Objective: to identify the correlation of uric acid and carotid intima media thickness in adolescents with obesity. Material and methods: an observational, cross-sectional study was carried out. Patients aged ten to 16 years with a diagnosis of obesity were included. Uric acid, lipid profile and carotid intima media thickness were determined. In relation to the statistical analysis, carotid intima media thickness was correlated with uric acid levels through Spearman's correlation coefficient. Results: one hundred and sixty-nine adolescents were included with a median age of 13 years, without predominance of sex. A positive correlation of uric acid with carotid intima media thickness was identified (r = 0.242, p = 0.001). When stratified according to sex, there was no correlation in women (r = -0.187, p = 0.074), while in men it increased (r = 0.36, p = 0.001) and by pubertal stage, pubertal male adolescents had a positive correlation (p = 0.384, p = 0.002). Conclusion: a weak positive correlation was identified between carotid intimal thickness and uric acid in obese adolescents.

Introducción: Introducción: la obesidad en la población pediátrica es un problema de salud pública. Se ha demostrado la correlación del ácido úrico y el grosor de la íntima media de la carótida en adultos. Objetivo: identificar la correlación del ácido úrico y el grosor de la íntima media de la carótida en adolescentes con obesidad. Material y métodos: se realizó un estudio observacional, transversal. Se incluyeron pacientes de diez a 16 años con diagnóstico de obesidad. Se determinó ácido úrico, perfil de lípidos y grosor de la íntima media carotidea. En el análisis estadístico, se correlacionó el grosor de la íntima media carotídea con los niveles de ácido úrico a través del coeficiente de correlación de Spearman. Resultados: se incluyeron 169 adolescentes con una mediana para la edad de 13 años, sin predominio de sexo. Se identificó una correlación positiva del ácido úrico con el grosor de la íntima media carotídea (r = 0,242, p = 0,001). Al estratificarse de acuerdo con el sexo, no hubo correlación en las mujeres (r = -0,187, p = 0,074), mientras que en los hombres aumentó (r = 0,36, p = 0,001) y por estadio puberal, los adolescentes varones púberes tuvieron una correlación positiva (p = 0,384, p = 0,002). Conclusión: se identificó una correlación positiva débil entre el grosor de la íntima de la carótida y el ácido úrico en adolescentes con obesidad.

Does uric acid-lowering treatment slow the progression of chronic kidney disease? A meta-analysis of randomized controlled trials.

INTRODUCTION: Hyperuricemia has been proposed as an independent factor in the development and progression of chronic kidney disease (CKD). However, the effect of uric acid-lowering therapies on delaying CKD progression is still uncertain. Therefore, this systemic review aims to assess the effect of uric acid-lowering therapies on renal outcomes in pre-dialysis CKD patients. METHODS: PubMed, Cochrane Library, and Lilacs databases were searched until April 24, 2021, for randomized clinical trials of CKD patients on uric acid-lowering treatment with xanthine-oxidase (XO) inhibitors. The weighted mean difference (WMD) or standard mean difference (SMD) with confidence interval (CI) were pooled using a random-effects model. RESULTS: Among 567 studies found, eighteen met the inclusion criteria (n=2463 participants). Compared to the patient's control group, the WMD for the glomerular filtration ratio (GFR) and serum creatinine changes of the treated group was 2.02ml/min/1.73m2 (95%CI 0.41 to 3.63, P=0.014) and -0.19mg/dl (95%CI -0.34 to -0.04, I2=86.2%, P=0.011), respectively. Subgroup analyses showed that the difference in follow-up time and CKD population type in the studies may explain the controversy about the role of uric acid-lowering therapies in CKD progression. The GFR and creatinine outcomes analysis by types of XO inhibitors showed no difference between the control and treated groups. Uric acid-lowering therapies were strongly associated with decreased serum uric acid and urinary protein-creatinine ratio and urinary albumin-creatinine ratio. CONCLUSIONS: These findings suggest that uric acid-lowering treatment may slow CKD progress and reduce protein and albumin excretion. However, larger and properly powered randomized clinical trials with specific CKD populations are needed to confirm these findings.

Association of serum uric acid with benefits of intensive blood pressure control.

INTRODUCTION AND OBJECTIVES: Intensive systolic blood pressure (SBP) control improved outcomes in the Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial. Whether the serum uric acid concentration at baseline alters the benefits of intensive SBP control is unknown. METHODS: The STEP trial was a randomized controlled trial that compared the effects of intensive (SBP target of 110 to<130mmHg) and standard (SBP target of 130 to <150mmHg) SBP control in Chinese patients aged 60 to 80 years with hypertension. The primary outcome was a composite of cardiovascular disease events. This post hoc analysis was performed to examine whether the effects of intensive SBP intervention differed by the baseline uric acid concentration using 2 models: restricted cubic spline curves and subgroup analyses, both based on the Fine-Gray subdistribution hazard model in the analysis of the primary outcome and secondary outcomes (excluding all-cause death). In the analysis of all-cause death, the Cox regression model was used. We also examined the change in the follow-up uric acid concentrations. RESULTS: Overall, the risk of the primary outcome rose as the cumulative uric acid concentration increased in both the intensive and standard treatment groups. Patients with intensive treatment had a lower multivariable-adjusted subdistribution hazard ratio for the primary outcome, but with a wide overlap of 95%CI. Next, we stratified patients according to their baseline uric acid concentration (tertile 1 [T1], <303.0µmol/L; tertile 2 [T2], 303.0 to <375.8µmol/L; and tertile 3 [T3], ≥375.8µmol/L). Subgroup analyses using tertiles provided HRs and 95%CI in T1 (HR, 0.55; 95%CI, 0.36-0.86; P=.008), T2 (HR, 0.80; 95%CI, 0.56-1.14; P=.22) and T3 (HR, 0.86; 95%CI, 0.60-1.21; P=.39), with an interaction P value of .29. The results for most of the secondary outcomes followed the same trends. CONCLUSIONS: There was no evidence that the benefit of the intensive SBP control differed by baseline uric acid concentrations. This trial was registered at ClinicalTrial.gov (Identifier: NCT03015311).

NRBP1 modulates uric acid transporter ABCG2 expression by activating the Wnt/ß-catenin pathway in HK-2 cells.

BACKGROUND: Nuclear receptor binding protein 1 (NRBP1) and ATP-binding cassette subfamily G member 2 (ABCG2) was the gout risk gene and high-capacity urate exporter respectively. However, the relationship between NRBP1 and ABCG2 and the underlying molecular mechanism contributing to these associations are unknown. METHODS: Firstly, the efficiency of the overexpression and knockdown of NRBP1 was confirmed by western blot. Next, the effect of NRBP1 overexpression and knockdown on the expression of ABCG2, organic anion transporter 1 (OAT1), glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) was detected by qRT-PCR and western blot. At the same time, the cellular location of ABCG2 and its expression after NRBP1 overexpression and knockdown was tested by immunofluorescence (IF) staining. Then, the mechanism of NRBP1 modulates ABCG2 expression was evaluated by western blot with or without the ß-catenin inhibitor (21H7). RESULTS: The lentivirus system was used to generate stable NRBP1 overexpression, while the plasmids carrying a NRBP1 siRNA was generated to knockdown NRBP1 expression in HK-2 cells. Meanwhile, the overexpression of NRBP1 significantly decreased the mRNAs and proteins expression of GLUT9 and URAT1, while the knockdown of NRBP1 increased the mRNAs and proteins expression of ABCG2 significantly. In addition, the NRBP1 modulates the expression of ABCG2 was by ctivating the Wnt/ß-catenin pathway in HK-2 cells according to the IF and western blot results. CONCLUSION: Taken together, our study demonstrated that NRBP1 inhibition played an essential role in attenuating hyperuricemia and gout by upregulation of ABCG2 via Wnt/ß-catenin signaling pathway in HK-2 cells.

Hyperuricaemia as a prognostic factor for acute ischaemic stroke. / Uricemia como factor pronóstico del ictus isquémico agudo.

INTRODUCTION: Recent studies on uric acid as a biomarker for the prognosis of acute stroke have found conflicting results. METHODS: We collected blood samples from 600 consecutively admitted patients at our tertiary hospital and analysed the relationship between uric acid levels and functional prognosis (measured using the modified Rankin Scale [mRS]). Patients who had received reperfusion therapy were excluded since this may have influenced uric acid levels. RESULTS: A total of 73% of patients had mRS scores ≤2; the mean uric acid level was 5.22mg/dL. We found a nonlinear relationship between functional prognosis at discharge and serum uric acid levels at admission when the National Institutes of Health Stroke Scale score was excluded from the analysis. CONCLUSIONS: Serum uric acid levels in patients with acute ischaemic stroke are significantly associated with functional prognosis at discharge, although this relationship is nonlinear. In fact, poorer prognosis is associated both with very low and with very high concentrations of uric acid. This suggests a dual role of uric acid in relation to stroke: on the one hand, as an associated risk factor, and on the other, as a possible neuroprotective factor due to its antioxidant effect.

Endoscopic identification of urinary stone composition: A study of South Eastern Group for Urolithiasis Research (SEGUR 2). / Identificación endoscópica de la composición de los cálculos urinarios: un estudio del Southeastern Group for Lithiasis Research (SEGUR 2).

INTRODUCTION AND OBJECTIVES: To assess the surgeon's ability to evaluate the composition of the stone by observation of endoscopic images. MATERIALS AND METHODS: A series of 20 video clips of endoscopic treatments of urinary stones of which was also available the result of infrared spectroscopy was uploaded to a YouTube site accessible only to members of the South Eastern Group for Urolithiasis Research (SEGUR) who were asked to identify the composition of the stones. RESULTS: A total of 32 clinicians from 9 different countries participated in the study. The average number of correct detections of participants was 7.81 ± 2.68 (range 1-12). Overall accuracy was 39% (250 out of 640 predictions). Calcium oxalate dihydrate stones have been correctly detected in 69.8%, calcium oxalate monohydrate in 41.8%, uric acid in 33.3%, calcium oxalate/uric acid in 34.3% and cystine in 78.1%. Precision rates for struvite (15.6%), calcium phosphate (0%) and mixed calcium oxalate/calcium phosphate (9.3%) were quite low. CONCLUSIONS: Observation of the stone during the endoscopic procedure was not reliable to identify the composition of most stones although it gave some information allowing to identify with a good sensitivity calcium oxalate dihydrate and cystine stones. Nevertheless, photo or video reporting of the intact stone and its internal structure could should be encouraged to implement results of still mandatory post-operative stone analysis. Endourologists should improve their ability of visual identification of the different types of stones.

[Urinary pH relevance on urolithiasis management.] / Importancia del pH urinario en la urolitiasis.

OBJECTIVE: Urinary pH is a factor that influences in urinary lithogenesis. It can condition the heterogeneous nucleation of calcium oxalate and the crystallization or dissolution of other substances such as uricacid, cystine and phosphates. Its exact and precise measurement is a tool to guide the treatment and prevention. The most accurate way to measure the pH is to use a glass electrode and a pH-meter, but this device is used in hospital's environment and is not portable. Test strips are not adequate for proper measurement. Recently, a portable and electronic device for measuring urinary pH has shown greater precision and accuracy in the measurement of urinary pH, with good acceptance by patients. METHOD: We carried out a bibliographic search inPUBMED and EMBASE using the terms "URINARY pH", "Lithiasis", "Uro-Lihitiasis", "Urinary Stone", "Urinary pH measurement", in order to compile articles, books, abstracts and the most relevant clinical guides in English and Spanish on this topic. RESULTS: We select a total of 66 articles, 3 books, an abstract of a study unpublished presented at the American urology congress and the European Guidelines on urolithiasis on the effect of pH on the formation and prevention of urolithiasis. Four articles deal specifically with the effect of urinary pH on urolithiasis, 5 articles deal with a new portable electronic device for measuring urinary pH, 5 articles dealt with the measurement of urinary pH with test strips and 1 article dealt with the modification of urinary pH to reduce fouling of double J catheters, 2 articles deal about the urinary acidification with oral methionine. The selected abstract deals with the new portable device for measuring urinary pH in cystinuric patients. The 3 selected books have specific sections where the role of urinary pH in urolithiasis is discussed. Finally, in the European Urology Guidelines, the control of urinary pH is emphasized in the sections of prevention of urolithiasis formation, treatment of uric lithiasis, infectious/non-infectious phosphocalcic and cystine. CONCLUSIONS: Urinary pH is a recognized factor in the scientific-urological community for the study, monitoring, treatment and prevention of lithiasic patients. Urinary pH measurement is a very useful tool, but test strips are not suitable for pH measurement and medical decision making. Currently, several studies have evaluated a new device to achieve the measurement of urinary pH effectively and easily by the patient, keeping urinary pH innon-lithogenic ranges with the association of medical and non-medical treatments, and good acceptability from the patients.

OBJETIVO: El pH urinario es un factorque influye en la litogénesis urinaria de forma importante. Puede condicionar la nucleación heterogénea del oxalato de calcio y la cristalización o disolución de otras sustancias como el ácido úrico, cistina y fosfatos. Su medición exacta y precisa es una herramienta para orientar el tratamiento y la prevención. La forma más precisa de medirlo es la utilización de un electrodo de vidrio y un pH-metro, pero este dispositivo es de uso hospitalario y no portátil. Las tiras reactivas no son fiables para una medición adecuada. Recientemente un dispositivo para medir el pH urinario, portátil y electrónico ha demostrado mayor precisión y exactitud en la medición del ph urinario, con buena aceptación por parte de los pacientes.MÉTODO: Realizamos una búsqueda bibliográfica en PUBMED y EMBASE utilizando los términos "URINARYpH", "Lithiasis", "Uro-Lihitiasis", "Urinary Stone", "UrinarypH measurement", con la finalidad de recopilar los artículos, libros, resúmenes y guías clínicas más relevantes en inglés y castellano sobre este tema. RESULTADOS: Recopilamos un total de 66 artículos, 3 libros, un resumen de un estudio presentado en el congreso americano de urología no publicado y las Guías Europeas de uro-litiasis sobre el efecto del pH en la formación y prevención de la litiasis urinaria. Cuatro artículos tratan específicamente sobre el pH urinario en la uro-litiasis, 5 artículos tratan sobre un dispositivo portable y electrónico para la medición del pH urinario, 5 artículos tratan sobre la medición del pH urinario con tiras reactivas. 1 artículo trata sobre la modificación del pH urinario para reducir incrustaciones de los catéteres doble J, 2 artículos tratan sobre la acidificación vía oral mediante metionina. El resumen seleccionado trata sobre el nuevo dispositivo portable para medir el pH urinario en pacientes cistinúricos. Los 3 libros tienen apartados específicos en dónde se comenta el papel del pH urinario en la uro-litiasis. Finalmente, en las Guías Europeas de Urología, se enfatiza el control del pH urinario en los apartados de prevención de formación de litiasis urinaria, tratamiento de litiasis úrica, fosfocálcica infecciosa/no infecciosa y cistina. CONCLUSIONES: El pH urinario es un factor reconocido en la comunidad científica - urológica dentro del estudio, seguimiento, tratamiento y prevención de los pacientes litiásicos. La medición del pH urinario es una herramienta muy útil. Las tiras reactivas no son precisas para la medición del pH y la toma de decisiones médicas. Actualmente diversos estudios han valorado un dispositivo para conseguir la medición del pH urinario de forma efectiva y sencilla por parte del paciente, de forma que se complemente con tratamientos médicos y no médicos para mantener el pH urinario en rangos no litogénicos, con buena aceptabilidad por parte de los pacientes.

Phase angle and metabolic parameters in severely obese patients.

INTRODUCTION: Introduction: obese patients present an inflammatory and metabolic profile that leads to oxidative stress and cellular damage. Phase angle is an indicator of cellular integrity and has been proposed as a prognostic parameter for changes in the metabolic profile. Objective: to investigate the possible association between phase angle and metabolic parameters in obese patients. Material and method: this was a cross-sectional study of adult obese patients who attended a specialized clinic between 2014 and 2016. All patients were ≥ 18 years of age, with a body mass index ≥ 35 kg/m2. All data were obtained from medical records and made part of the clinical protocol. Patients were divided into two groups using a cutoff point for phase angle, and the groups were compared using the Kruskal-Wallis or Chi-squared test for quantitative and categorical variables, respectively. Correlations were identified by Spearman's and Pearson's correlation analyses. All between-group differences were considered statistically significant at p ≤ 0.05. Results: a low phase angle was present in 30.5 % of the 141 patients enrolled in the study. We found an association between low phase angle and presence of hyperuricemia (p = 0.018) when adjusted for waist circumference, dysglycemia, arterial hypertension, and hyperuricemia. There was no correlation between phase angle and the components of body composition. Conclusions: there is an association of phase angle with uric acid levels, but not with other metabolic parameters.

INTRODUCCIÓN: Introducción: los pacientes obesos presentan un perfil inflamatorio y metabólico que provoca estrés oxidativo y daño celular. El ángulo de fase es un indicador de integridad celular que se ha propuesto como parámetro pronóstico de los cambios del perfil metabólico. Objetivo: investigar la posible asociación entre el ángulo de fase y los parámetros metabólicos en pacientes obesos. Material y método: este fue un estudio transversal de pacientes obesos adultos que asistieron a una clínica especializada entre 2014 y 2016. Todos los pacientes tenían ≥ 18 años de edad y un índice de masa corporal ≥ 35 kg/m2. Todos los datos se obtuvieron de los registros médicos y formaron parte del protocolo clínico. Los pacientes se dividieron en dos grupos usando un punto de corte para el ángulo de fase, y los grupos se compararon usando la prueba de Kruskal-Wallis o del chi cuadrado para las variables cuantitativas y categóricas, respectivamente. Las correlaciones se identificaron mediante el análisis de correlación de Spearman y el de Pearson. Todas las diferencias entre grupos se consideraron estadísticamente significativas si p ≤ 0.05. Resultados: se observó un ángulo de fase bajo en el 30,5 % de los 141 pacientes incluidos en el estudio. Encontramos una asociación entre el ángulo de fase bajo y la presencia de hiperuricemia (p = 0.018) cuando se ajustó para la circunferencia de la cintura, la disglucemia, la hipertensión arterial y la hiperuricemia. No hubo correlación entre el ángulo de fase y los componentes de la composición corporal. Conclusiones: el ángulo de fase presenta asociación con los niveles plasmáticos de ácido úrico pero no con otros parámetros metabólicos.

[Uric acid and its association with the components of the metabolic syndrome in Colombian adolescents]. / Ácido úrico y su asociación con los componentes del síndrome metabólico en adolescentes colombianos.

INTRODUCTION: Background: the relationship of uric acid and the development of cardiometabolic diseases has been studied in recent years. However, the controversy continues to consider this finding as an independent risk factor for cardiovascular disease at early ages. The objective was to establish the prevalence of serum levels of altered uric acid and its association with the metabolic syndrome components in adolescents from Bucaramanga, Colombia. Methods: an analytical cross-sectional study, nested in a population cohort, with a sample of 494 re-contacted adolescents from the original study. The dependent variables were metabolic syndrome and its component criteria. The main independent variable was uric acid values, classified into two categories: uric acid at risk (values greater than 5.5 mg/dl) and high uric acid (greater than 6.5 mg/dl). Logistic regression models were used, adjusted for sex, age and body mass index to determine the association between the variables of interest. Results: the prevalence of uric acid at risk was 37.25% (CI 95%, 32.9-41.5) and the proportion of high uric acid was 18.42% (CI 95%, 14.9-21, 8), significantly higher in men than in women (p < 0.0001). Adolescents with high levels of uric acid were more likely to have abdominal obesity (OR: 3.03, CI 95% 1.38-6.64), high blood pressure (OR: 1.11, CI 95%, 1.05-2.07), hypertriglyceridemia (OR: 4.94, CI 95%, 2.98-8.19) and altered fasting glycemia (OR: 5.15, CI 95%, 3.42-11.05). Conclusions: the results suggest the existence of a positive relationship between the presence of high levels of uric acid and metabolic cardio-risk factors.

INTRODUCCIÓN: Introducción: la relación del ácido úrico y el desarrollo de enfermedades cardiometabólicas se ha estudiado en los últimos años. No obstante, continúa la controversia en considerar este hallazgo como un factor de riesgo independiente para enfermedad cardiovascular en edades tempranas. El objetivo fue establecer la prevalencia de niveles séricos de ácido úrico alterados y su asociación con los componentes del síndrome metabólico en adolescentes de Bucaramanga, Colombia. Metodología: estudio de corte transversal analítico, anidado en una cohorte poblacional, con una muestra de 494 adolescentes recontactados del estudio original. Las variables dependientes fueron: síndrome metabólico y criterios que lo componen. La variable independiente principal fueron los valores de ácido úrico, clasificados en dos categorías: ácido úrico a riesgo (valores mayores a 5,5 mg/dl) y ácido úrico elevado (mayores de 6,5 mg/dl). Se usaron modelos de regresión logística, ajustados por sexo, edad e índice de masa corporal para determinar la asociación entre las variables de interés. Resultados: la prevalencia de ácido úrico a riesgo fue del 37,25% (IC 95%, 32,9-41,5) y la proporción de ácido úrico elevado fue del 18,42% (IC 95%, 14,9-21,8), significativamente mayor en hombres que en mujeres (p < 0,0001). Los adolescentes con niveles elevados de ácido úrico mostraron mayor probabilidad de presentar obesidad abdominal (OR: 3,03; IC 95% 1,38-6,64), presión arterial alta (OR: 1,11; IC 95% 1,05-2,07), hipertrigliceridemia (OR: 4,94; IC 95%, 2,98-8,19) y glucemia en ayuno alterada (OR: 5,15; IC 95%, 3,42-11,05). Conclusiones: los resultados sugieren la existencia de una relación positiva entre la presencia de niveles de ácido úrico elevados y los factores de riesgo cardiometabólico.

Hipouricemia renal hereditaria tipo 1 y 2 en tres niños españoles. Revisión de casos pediátricos publicados.

Hereditary renal hypouricemia is a rare autosomal recessive genetic disorder that involves an isolated defect in uric acid reabsorption at the renal tubules. Patients present with serum uric acid concentrations of less than 2mg/dl (119 micromol/L) with increased fractional excretion above 10%. Most of the patients are asymptomatic and are detected incidentally. However, complications such us nephrolithiasis, hematuria, acute renal failure exercise-induced or after dehydration for acute gastroenteritis, or posterior reversible encephalopaty syndrome (PRES) may develop. Hereditary renal hypouricemia is confirmed by molecular genetic analysis of the two genes which codify the uric acid transport in the kidney tubules. The renal hypouricemia type 1 (OMIM 220150) is characterized by loss-of-function mutations in the SLC22A12 gene which encodes URAT 1 transporter, and the hypouricemia type 2 (OMIM 612076) is caused by defects in the SLC2A9 gene. Homozygous mutations of SLC2A9 cause the most severe forms of the disease. Most mutations have been identified in Japanese adults, and only a few in children. We describe three asyntomatic pediatric Spanish patients with renal hypouricemia, with genetic confirmation, and we make a revision of all of the pediatric cases with genetic study published in the literature.

Continuous Positive Airway Pressure Treatment Does not Reduce Uric Acid Levels in OSA Women.

OBJECTIVES: Although an association between uric acid (UA) levels and obstructive sleep apnea (OSA) has been reported, the effect of continuous positive airway pressure (CPAP) on this measure is yet unclear. We aimed to investigate the effect of CPAP therapy on serum UA levels in patients with OSA. METHODS: We conducted a multicenter, open-label, randomized controlled trial in 307 women diagnosed with moderate-to-severe OSA (apnea-hypopnea index [AHI]≥15) in 19 Spanish Sleep Units. Women were randomized to CPAP (n=151) or conservative treatment (n=156) for 12 weeks. Changes in serum UA measures were assessed on an intention-to-treat basis. Additional analyses were conducted in the subgroup of women with CPAP adherence ≥4h/night and those with UA levels ≥6mg/dl. RESULTS: Women had a mean (SD) age of 57.1 (10.1) years, median (first-third quartile) body mass index of 33.7 (29.0-38.5) mg/kg2 and AHI of 32.0 (22.6-48.5). The average serum UA measure was 5.11 (1.26) mg/dl, and 80 (26.1%) participants had UA≥6mg/dl. Compared with the control group, the CPAP group did not achieve any reduction in UA levels (non-adjusted intergroup difference -0.03mg/dl, 95%CI -0.20 to 0.13; p=0.702) after 12 weeks of follow-up. These results did not change when the analysis was restricted to women with CPAP adherence ≥4h/night, or the subgroup of women with hyperuricemia. CONCLUSIONS: Twelve weeks of CPAP therapy does not reduce UA levels compared to conservative treatment in women with moderate-to-severe OSA.

Impact of uric acid levels on the risk of long-term cardiovascular mortality in patients with type 2 diabetes mellitus. / Influencia de los niveles de ácido úrico sobre el riesgo de mortalidad cardiovascular a largo plazo en pacientes con diabetes de tipo 2.

BACKGROUND: Hyperuricemia is associated to cardiovascular disease. However, the contribution of uric acid (UA) to cardiovascular mortality in diabetic patients is controversial. OBJECTIVE: To assess the impact of UA levels on the risk of cardiovascular mortality risk in a cohort of patients with type 2 diabetes mellitus (T2DM). PATIENTS AND METHODS: A prospective cohort study on outpatients with T2DM. The clinical endpoint was cardiovascular death. Anthropometric, demographic, clinical, and biochemical variables were collected, including UA levels, urinary albumin excretion and estimated glomerular filtration rate. The independent contribution of UA levels to cardiovascular mortality was assessed using multivariate Cox regression models, progressively adjusted for potential confounders. RESULTS: A total of 452 patients with a mean age of 65.9 (SD 9.5) years were enrolled. Mean UA level was 4.2mg/dL. Quartiles of UA levels were Q1 < 3.3; Q2: 3.3-4.2; Q3: 4.3-5.1; Q4 > 5.1mg/dL. UA levels significantly correlated with estimated glomerular filtration rate (Rho=-0.227; p<0.001). During a median follow-up time of 13 years, cardiovascular mortality rates were higher in Q4 of the UA distribution (Q1: 10.7; Q2: 11.7; Q3: 10.7; Q4: 21.6 per 1000 patient-years; p = 0.027). UA was a predictor of cardiovascular mortality in the univariate analysis (HR1mg/dL = 1.30; p=0.002), but not in a multivariate analysis adjusted for urinary albumin excretion and eGFR (HR1mg/dL=1.20; p=0.12). DISCUSSION AND CONCLUSIONS: High UA levels are associated to cardiovascular mortality in patients with T2DM. However, the role of UA may be mediated by impaired kidney function in patients with hyperuricemia.