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.

Role of HIF1A gene polymorphisms with serum uric acid and HIF-1α levels in monosodium urate crystal-induced arthritis.

BACKGROUND: Gouty arthritis is a metabolic disease characterized by the deposition of monosodium urate crystals in the joints, which triggers the release of interleukin-1ß (IL-ß) by activating the NLRP3 inflammasome. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor involved in IL-ß production and as a regulator of NLRP3. OBJECTIVES: The aims were to analyze the association of HIF1A rs11549465, rs11549467, and rs2057482 variants in patients with gouty arthritis, and to evaluate the correlation between urate and HIF-1α levels according to the associated genotypes. METHODS: Cases and controls were genotyped using TaqMan probes, and urate and HIF-1α levels were quantified. Data were analyzed using SPSS v21 software and P-values < 0.05 were considered statistically significant. RESULTS: Urate and HIF-1α levels were higher in patients than in controls (P < 0.05). Under the three inheritance models (codominant, dominant, and recessive), the AA genotype of the rs11549467 variant was associated with gout risk (OR = 5.74, P = 0.009, OR = 3.33, P = 0.024, and OR = 9.09, P = 0.003, respectively). There were significant differences in the distribution of serum levels of both HIF-1α (P < 0.0001) and urate (P = 0.016) according to the genotypes of the rs11549467 variant. CONCLUSION: These results suggest that the HIF1A rs11549467 variant may play a key role in the pathogenesis of gouty arthritis. Key Points • The pathogenesis of gouty arthritis involves the HIF1A gene. • In patients with gout, the AA genotype of the rs11549467 (HIF1A) variant is associated with increased serum levels of urate and HIF-1α. • HIF-1α is involved in the regulation of IL-1ß and NLRP3.

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.

Relationship between serum uric acid, nocturnal hypertension and risk for preeclampsia in high-risk pregnancies.

To analyze the possible association between serum uric acid (SUA) and nocturnal hypertension and to evaluate the ability of these variables (alone or in combination) to predict preeclampsia (PE) we conducted a historical cohort study in 532 high-risk pregnancies. Women were divided according to SUA values and nocturnal blood pressure (BP) into four groups: 1- normal SUA and nocturnal normotension; 2- high SUA and nocturnal normotension; 3- normal SUA and nocturnal hypertension and 4- high SUA and nocturnal hypertension. High SUA was defined by the top quartile values and nocturnal hypertension as BP ≥ 120/70 mmHg, using ambulatory blood pressure monitoring (ABPM), during nocturnal rest. Risks for PE were compared using logistic regression. SUA had a weak but significant correlation with daytime systolic ABPM (r = 0.11, p = 0.014), daytime diastolic ABPM (r = 0.13, p = 0.004), nighttime systolic ABPM (r = 0.16, p < 0.001) and nighttime diastolic ABPM (r = 0.18, p < 0.001). Also, all ABPM values were higher in women with high SUA. The absolute risk of PE increased through groups: 6.5%, 13.1%, 31.2%, and 47.9% for groups 1, 2, 3, and 4, respectively, p < 0.001. Compared with Group 1, Group 3 (OR 6.29 95%CI 3.41-11.60), but not Group 2 (OR 2.15 95%CI 0.88-5.24), had statistically significant higher risk for PE. Group 4 (women with both, high SUA and nocturnal hypertension) had the highest risk (OR 13.11 95%CI 6.69-25.70). Risks remained statistically significant after the adjustment for relevant variables. In conclusion, the combination of SUA > 4 mg/dL and nocturnal BP > 120/70 mmHg implies a very high risk to developed PE.

Predictors of autosomal dominant polycystic kidney disease progression: a Brazilian single-center cohort.

INTRODUCTION: Identifying risk factors for autosomal dominant polycystic kidney disease (ADPKD) progression is important. However, studies that have evaluated this subject using a Brazilian sample is sparce. Therefore, the aim of this study was to identify risk factors for renal outcomes and death in a Brazilian cohort of ADPKD patients. METHODS: Patients had the first medical appointment between January 2002 and December 2014, and were followed up until December 2019. Associations between clinical and laboratory variables with the primary outcome (sustained decrease of at least 57% in the eGFR from baseline, need for dialysis or renal transplantation) and the secondary outcome (death from any cause) were analyzed using a multiple Cox regression model. Among 80 ADPKD patients, those under 18 years, with glomerular filtration rate <30 mL/min/1.73 m2, and/or those with missing data were excluded. There were 70 patients followed. RESULTS: The factors independently associated with the renal outcomes were total kidney length - adjusted Hazard Ratio (HR) with a 95% confidence interval (95% CI): 1.137 (1.057-1.224), glomerular filtration rate - HR (95% CI): 0.970 (0.949-0.992), and serum uric acid level - HR (95% CI): 1.643 (1.118-2.415). Diabetes mellitus - HR (95% CI): 8.115 (1.985-33.180) and glomerular filtration rate - HR (95% CI): 0.957 (0.919-0.997) were associated with the secondary outcome. CONCLUSIONS: These findings corroborate the hypothesis that total kidney length, glomerular filtration rate and serum uric acid level may be important prognostic predictors of ADPKD in a Brazilian cohort, which could help to select patients who require closer follow up.

Diagnostic performance of sixteen biomarkers for MASLD: A study in a Mexican cohort.

BACKGROUND AND AIMS: Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD) poses a heightened cardiovascular risk. Identifying efficient biomarkers for early MASLD detection in resource-limited Latin American regions is crucial. We aimed to evaluate the diagnostic efficacy of sixteen biomarkers for MASLD in Mexican individuals. METHODS: In this cross-sectional and analytical study, steatosis was assessed using vibration-controlled transient elastography. MASLD was defined according to international standards. Assessed biomarkers included: Visceral Fat (VF), Waist Circumference (WC), Waist-Height Ratio (WHtr), Waist-Hip Ratio (WHr), Visceral Adiposity Index (VAI), Hepatic Steatosis Index (HSI), Body Mass Index (BMI), Homeostatic Model Assessment (HOMA), Weight-Adjusted-Waist Index (WWI), Lipid Accumulation Product (LAP), Uric Acid-Creatinine Ratio (UACR), Triglyceride-Glucose Index (TyG) and its variants TyG-WC, TyG-HDL, TyG-BMI, TyG-WHtr. RESULTS: 161 participants were included, of which 122 met MASLD criteria (56 % women, age 53.9 years [47.5-64]) and 39 were healthy controls (76 % women, age 52 [45-64]). The AUROCs of the biomarkers for MASLD were: TyG-WC (0.84), LAP (0.84), TyG-BMI (0.82), TyG-WHtr (0.80), WC (0.78), TyG (0.77), WHtr (0.75), BMI (0.76), VF (0.75), HSI (0.75), TyG-HDL (0.75), WHr (0.72), VAI (0.73), UA/CR (0.70), HOMA (0.71), and WWI (0.69). Sex-based differences were observed. After adjusting for sociodemographic variables, the TyG-WC index was the best predictor of MASLD. CONCLUSIONS: In conclusion, our results underscore the potential of several noninvasive biomarkers for MASLD assessment in a Mexican population, highlighting variations in diagnostic efficacy and cut-off values between sexes. After adjusting, TyG-WC was the best MASLD predictor.

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.

Non-enzymatic biosensor based on F,S-doped carbon dots/copper nanoarchitecture applied in the simultaneous electrochemical determination of NADH, dopamine, and uric acid in plasma.

This work presents the synthesis and characterization of an innovative F,S-doped carbon dots/CuONPs hybrid nanostructure obtained by a direct mixture between F,S-doped carbon dots obtained electrochemically and copper nitrate alcoholic solution. The hybrid nanostructures synthesized were characterized by absorption spectroscopy in the Ultraviolet region (UV-vis), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and different electrochemical techniques. The fluoride and sulfur-doped carbon dots/CuONPs nanostructures were used to prepare a non-enzymatic biosensor on a printed carbon electrode, exhibiting excellent electrocatalytic activity for the simultaneous determination of NADH, dopamine, and uric acid in the presence of ascorbic acid with a detection limit of 20, 80, and 400 nmol L-1, respectively. The non-enzymatic biosensors were also used to determine NADH, dopamine, and uric acid in plasma, and they did not suffer significant interference from each other.

Verificación y transferencia de intervalos de referencia de variables bioquímicas de rutina / Verification and transfer of reference intervals of routine biochemical variables

Introducción. El correcto análisis en la interpretación de los resultados de cualquier analito biológico es esencial para la salud del paciente y está fuertemente ligado a contrastar dichos resultados con los intervalos biológicos referenciales que estén acorde a la población que está siendo analizada diariamente. El objetivo de este artículo, fue establecer intervalos referenciales (IR) en adultos para glicemia, urea, creatinina, ácido úrico, colesterol total y triglicéridos en un laboratorio clínico y comparar los valores obtenidos con los incluidos en los insertos para ese rango de edad. Metodología. La población fue de 561 adultos de ambos sexos, aparentemente sanos, que acudieron a Biomasterclin Laboratorio en Valencia, Venezuela, y cuyas edades fueron de 57,1±18,1 años. Resultados. Los IR obtenidos fueron glicemia 63,0-108,8 mg/dL, urea 17,7-54,9 mg/dL, creatinina 0,60-1,41 mg/dL, ácido úrico 0,89-7,26 mg/dL, colesterol total 78,5-251,1 mg/dL y triglicéridos 39,5-176,0 mg/dL. Los IR propuestos por la casa comercial empleada para la determinación de la glicemia y la creatinina pudieron ser transferidos a la población evaluada, mientras que el resto de los IR no. Conclusión. Debido a las diferencias que se presentan entre los IR en los estuches comerciales comparados con los de la población de individuos que acuden a los laboratorios clínicos, se hace necesario establecer IR para ser empleados en cada laboratorio clínico

The correct analysis in the interpretation of the results of any biological analyte is essential for the health of the patient and it is strongly linked to comparing those results with reference ranges that are in accordance with the population that is being analyzed on a daily basis. The objective of this study was to establish reference ranges in adults for glycemia, urea, creatinine, uric acid, total cholesterol and triglycerides in a clinical laboratory and compare the values obtained with those included in the inserts for the corresponding age group. Methodology. The population consisted of 561 apparently healthy adults of both sexes that attended Biomasterclin Laboratorio in Valencia, Venezuela, whose ages were 57.1±18.1 years. Results. The reference ranges obtained for glycemia were 63.0- 108.8 mg/dL, urea 17.7-54.9 mg/dL, creatinine 0.60-1.41 mg/dL, uric acid 0.89- 726 mg/dL, total cholesterol 78.5-251.1 mg/dL and triglycerides 39.5-176.0 mg/ dL. The reference ranges proposed by the commercial kits used for the determination of glycemia and creatinine could be transferred to the evaluated population, while the rest of the reference ranges could not. Conclusion. Due to the differences that occur between the reference ranges in commercial kits compared to those of the population of individuals who attend clinical laboratories, it is necessary to establish reference values in each clinical laboratory

Association of uric acid and uric acid to creatinine ratio with chronic kidney disease in hypertensive patients.

BACKGROUND: Recent studies have shown that the serum uric acid/creatinine ratio (SUA/SCr) is a better predictor of chronic kidney disease (CKD) than serum uric acid (SUA) isolated. The aim of the present study was to evaluate the association of isolated SUA and the SUA/SCr with CKD in hypertensive patients. METHODS: Cross-sectional study conducted with hypertensive patients followed-up by the Primary Health Care Service (PHC). Sociodemographic, economic, lifestyle, clinical, anthropometric, and biochemical variables were evaluated. The association between SUA parameters (quartiles of SUA and quartiles of SUA/SCr) and CKD was evaluated by bivariate and multivariate logistic regression. The association between SUA parameters (SUA and SUA/SCr) and estimated glomerular filtration rate (eGFR) was evaluated by linear regression. The analyses were performed considering four adjustment models. SUA and SUA/SCr were compared by receiver operating characteristic (ROC) curve. RESULTS: In the fully adjusted model, SUA was positively associated with the presence of CKD (OR = 6.72 [95 % CI 1.96-22.96]) and inversely associated with eGFR (ß Coef. = -2.41 [95 % CI -3.44; -1.39]). SUA/SCr was positively associated with eGFR (ß Coef. = 2.39 [1.42; 3.36]). According to the ROC curve, the SUA is a better predictor of CKD than the SUA/SCr. CONCLUSIONS: Elevated levels of isolated SUA were associated with CKD and eGFR. However, the SUA/SCr was not associated with CKD. We do not recommend using the SUA/SCr to predict CKD in hypertensive patients.

High uric acid levels in overweight and obese children and their relationship with cardiometabolic risk factors: what is missing in this puzzle?

OBJECTIVES: The prevalence of hyperuricemia, a common disorder, has been increasing. Moreover, the association between obesity, serum uric acid levels, and cardiometabolic markers in children is unclear. Therefore, this study aimed to analyze the inter-relationships between these factors in a sample of children aged 6-12 years. METHODS: We evaluated 764 children and stratified them according to their body mass index (BMI). Blood pressure and uric acid, creatinine, lipid, and glycemic profiles were evaluated, and the estimated glomerular filtration rate (eGFR) and the homeostatic model assessment for insulin resistance (HOMA-IR) index were calculated. RESULTS: There was a significant linear trend of increasing systolic blood pressure (SBP), diastolic blood pressure (DBP), triglycerides (TG), total cholesterol, low-density lipoprotein cholesterol (LDLc), uric acid, insulin levels, and HOMA-IR index values corresponding with overweight and obese groups; however, high-density lipoprotein cholesterol (HDLc) levels decreased with increasing obesity. The mean creatinine level and eGFR were similar across all BMI groups. Uric acid levels were significantly correlated with BMI (r=0.527), waist circumference (r=0.580), SBP (r=0.497), DBP (r=0.362), TG (r=0.534), total cholesterol (r=0.416), LDLc (r=0.286), HDLc (r=-0.248), insulin (r=0.613), and HOMA-IR index (r=0.607). Multiple regression analyses showed that BMI (B=0.071; SE=0.012; p<0.001), TG (B=0.004; SE=0.001; p<0.001), LDLc (B=0.003; SE=0.001; p=0.006), and insulin (B=0.066; SE=0.007; p<0.001) (R2=0.460) were significant predictors of increased uric acid levels and explained 46% of the variability in uric acid in these children. CONCLUSIONS: Our findings suggest that overweight or obese children are more likely to have higher uric acid levels. Moreover, several cardiometabolic risk factors were strongly associated with high uric acid levels.

Sugar-sweetened soft drinks consumption and risk of hyperuricemia: Results of the ELSA-Brasil study.

BACKGROUND AND AIMS: The prospective association between sugar-sweetened beverages consumption and hyperuricemia is controversial. The aim was to investigate the association of the consumption of sugar-sweetened soft drinks and unsweetened fruit juices with the incidence of hyperuricemia and the levels of serum uric acid in the participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS AND RESULTS: Longitudinal analysis in ELSA-Brasil participants (baseline 2008-2010 and follow-up 2012-2014). The sample consisted of 10,072 civil servants (35-74 years, both sexes). The consumption of beverages estimated by a food frequency questionnaire (baseline) was divided into five categories: nonconsumption and quartiles (≥0.1 mL/day). Hyperuricemia was defined as uric acid ≥7.0 mg/dL (men) and ≥5.7 mg/dL (women). Poisson regression with robust variance and multiple linear regression were tested. The average consumption of soft drinks was 84 ± 191 mL/day in men and 42 ± 128 mL/day in women. After 4 years of follow-up, the higher consumption of soft drinks (men: 401 ± 303 mL/day; women: 390 ± 290 mL/day) increased the relative risk of hyperuricemia by 30% (men) and 40% (women), and was associated with increased mean uric acid (men: ß = 0.14 mg/dL; 95% CI 0.41-0.24; women: ß = 0.11 mg/dL; 95% CI 0.00-0.21). The consumption of unsweetened juice was not associated with hyperuricemia. CONCLUSION: High consumption of sugar-sweetened soft drinks is associated with an increased relative risk of hyperuricemia and elevated serum uric acid levels in Brazilian adults.

Uric acid: A new marker for metabolic syndrome? Results of a population-based study with adults.

BACKGROUND AND AIMS: Recently, studies have shown a positive association between serum uric acid (UA) and metabolic syndrome (MS). To evaluate the predictive capacity and the association of serum UA with pre-MS and MS, by sex, in adults. METHODS AND RESULTS: Cross-sectional study with 932 adults, of both sexes, from Viçosa, Minas Gerais (MG), Brazil. Sociodemographic and behavioral data were obtained through a questionnaire and anthropometric, clinical, and biochemical evaluation. We used multinomial logistic regression and the area under receiver operating characteristic curve (AUC). The prevalence of pre-MS was 17.8% and of MS was 26.5%. The fitted models showed positive association of serum UA with pre-MS (OR = 1.62, 95% CI = 1.09-2.40) and MS (OR = 2.61, 95% CI = 1.99-3.42) among men. For women, similar results were found for MS (OR = 2.59, 95% CI = 1.81-3.73). The optimal cutoff points obtained by AUC for pre-MS and MS were 4.7 and 4.9 mg/dL among men and 3.1 and 3.4 mg/dL among women, respectively. CONCLUSION: The results point to a positive association of UA with pre-MS and MS, with no significant differences between sexes. Therefore, UA can be used as an additional marker in the screening of these conditions.

Urolithiasis and sleeve gastrectomy: a prospective assessment of urinary biochemical variables.

INTRODUCTION: to evaluate urinary biochemical alterations related to urolithogenesis processes after sleeve gastrectomy (SG). MATERIALS AND METHODS: : prospective study with 32 individuals without previous diagnosis of urolithiasis who underwent SG. A 24-h urine test was collected seven days prior to surgery and at 6-month follow-up. The studied variables were urine volume, urinary pH, oxalate, calcium, citrate, and magnesium and calcium oxalate super saturation (CaOx SS). RESULTS: patients were mainly women (81.2%), with mean age of 40.6 years. Mean pre- and postoperative BMI were 47.1 ± 8.3 Kg/m2 and 35.5 ± 6.1 Kg/m2, respectively (p<0.001). Urine volume was significantly lower at the postoperative evaluation in absolute values (2,242.50 ± 798.26 mL x 1,240.94 ± 352.39 mL, p<0.001) and adjusted to body weight (18.58 ± 6.92 mL/kg x 13.92 ± 4.65 mL/kg, p<0.001). CaOx SS increased significantly after SG (0.11 ± 0.10 x 0.24 ± 0.18, p<0.001). Moreover, uric acid levels were significantly lower at the postoperative evaluation (482.34 ± 195.80 mg x 434.75 ± 158.38 mg, p=0.027). Urinary pH, oxalate, calcium, citrate, and magnesium did not present significant variations between the pre- and postoperative periods. CONCLUSION: SG may lead to important alterations in the urinary profile. However, it occurs in a much milder way than that of RYGB.

Serum uric acid is positively associated with muscle strength in older men and women: Findings from NHANES 1999-2002.

BACKGROUND: One of the causes of strength loss in older adults is the increased oxidative stress; thus, substances with antioxidants properties may have protective effects on muscle strength. Uric acid (UA) is an important antioxidant and it seems to be positively associated with muscle strength in older adults; however, the current evidence is still limited. AIM: To investigate whether serum UA is associated with muscle strength in older men and women. METHODS: A cross-sectional study was performed evaluating older adults aged from 50 to 85 years from National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2361 individuals (1256 men and 1105 women) were evaluated. The peak isokinetic knee extensor strength was assessed by kinetic communicator isokinetic dynamometer; while UA levels were measured by colorimetric method. Linear regression analyses were performed to estimate the coefficients and 95% confidence intervals for muscle strength by quintiles of UA levels, adjusted for potential confounders. RESULTS: In the unadjusted analyses, serum UA was positively associated with peak force in men and total sample, but not in women. However, after adjustments for confounders, UA levels were positively associated with peak force in total sample (p-trend = 0.007), men (p-trend = 0.044) and women (p-trend = 0.016). CONCLUSION: Serum UA is positively associated with muscle strength in older men and women. These results suggest that UA levels seem to be a protective factor for muscle strength in older adults independent of the sex.

Uric acid reference values: report on 1750 healthy Brazilian children and adolescents.

BACKGROUND: Our purpose was to determine reference values and determinants of serum uric acid (SUA) in children and adolescents. METHODS: A fasting blood sample was collected from 1750 schoolchildren and adolescents (6-17 years). Puberty was defined according to the Tanner scale. Bodyweight, muscle mass, and body fat percentage were determined by bioimpedance. Data are given as cut-offs and mean ± standard deviation. RESULTS: SUA level was higher in children that had already entered puberty (4.2 ± 1.1 mg/dL) than among prepubescent (3.6 ± 0.8 mg/dL; p < 0.01). Considering the 90 percentile (p90) as the upper reference value, the following values are proposed for boys and girls, respectively: <10 years or prepubescent: ≤4.5 mg/dL and ≤4.8 mg/dL; from 10 to 13 years: ≤5.7 mg/dL and ≤5.2 mg/dL; from 14 to 17 years: ≤6.4 mg/dL and ≤5.3 mg/dL. Muscle mass explained part of the variability in SUA after pubescence, acting as an independent variable for higher levels of SUA. CONCLUSIONS: The sex, age, and phase of puberty influence SUA reference levels, and part of this influence could be explained by the higher muscle mass, mainly after the adolescence onset. IMPACT: The key message of this study is that high levels of uric acid in the blood are associated with metabolic syndrome and cardiovascular risk factors. These diseases should be prevented since the infancy However, it is necessary to establish reference values of uric acid (SUA) for children and adolescents. The Brazilian population is highly admixed and these values were not determined so far. We studied a robust sample of Brazilian schoolchildren and adolescents (6-17 years) and defined the 90th percentile of uric acid as the upper limit of normality for sex, age, and pubertal stage. These values can be used as a reference for other populations with similar characteristics.

Association of uric acid with cardiovascular risk in Brazilian children and adolescents.

BACKGROUND AND AIM: Hyperuricemia in adults is associated with cardiovascular risk factors. However, there is less data regarding this association in children and adolescents. Our purpose was to determine association between serum uric acid (SUA) and cardiovascular risk. METHODS AND RESULTS: A fasting blood sample was collected from 1750 participants aged 6-17 years enrolled in a social project and public schools in Espírito Santo, Brazil. Internal cut-offs were generated to define high SUA (≥90th percentile of SUA concentration for sex and age group). Body mass index percentile (pBMI), body fat percentage (BFP) and muscle mass were determined by bioimpedance. Data are given as mean ± standard deviation. High SUA was associated with overweight/obesity (OR 3.7 CI 95% 2.7-5.0), high waist circumference (WC) (OR 3.9 CI 95% 2.9-5.4), low HDL (OR 2.0 CI 95% 1.5-2.8), high blood pressure (BP) (OR 1.8 CI 95% 1.1-3.2), high BFP (OR 4.1 CI 95% 2.7-6.4), metabolic syndrome (MetS) (OR 3.6 CI 95% 1.8-7.1) and insulin resistance (OR 1.7 CI 95% 1.1-2.7). Individuals in the fourth quartile of SUA, compared to those in the first quartile, showed higher age, pBMI, WC, BFP and muscle mass. Using a reference value of 5.5 mg/dL, the prevalence of hyperuricemia in the sample was 10.3% (CI 95% 8.9-11.7%). CONCLUSION: Higher SUA values are associated with higher cardiovascular risk in childhood and adolescence. The main cardiovascular risk factors associated with hyperuricemia were overweight/obesity, high WC, dyslipidemia, high BFP, high BP, insulin resistance and MetS.

Urolithiasis and sleeve gastrectomy: a prospective assessment of urinary biochemical variables / Urolitíase e gastrectomia vertical: uma avaliação prospectiva das variáveis bioquímicas urinárias

ABSTRACT Introduction: to evaluate urinary biochemical alterations related to urolithogenesis processes after sleeve gastrectomy (SG). Materials and methods : prospective study with 32 individuals without previous diagnosis of urolithiasis who underwent SG. A 24-h urine test was collected seven days prior to surgery and at 6-month follow-up. The studied variables were urine volume, urinary pH, oxalate, calcium, citrate, and magnesium and calcium oxalate super saturation (CaOx SS). Results: patients were mainly women (81.2%), with mean age of 40.6 years. Mean pre- and postoperative BMI were 47.1 ± 8.3 Kg/m2 and 35.5 ± 6.1 Kg/m2, respectively (p<0.001). Urine volume was significantly lower at the postoperative evaluation in absolute values (2,242.50 ± 798.26 mL x 1,240.94 ± 352.39 mL, p<0.001) and adjusted to body weight (18.58 ± 6.92 mL/kg x 13.92 ± 4.65 mL/kg, p<0.001). CaOx SS increased significantly after SG (0.11 ± 0.10 x 0.24 ± 0.18, p<0.001). Moreover, uric acid levels were significantly lower at the postoperative evaluation (482.34 ± 195.80 mg x 434.75 ± 158.38 mg, p=0.027). Urinary pH, oxalate, calcium, citrate, and magnesium did not present significant variations between the pre- and postoperative periods. Conclusion: SG may lead to important alterations in the urinary profile. However, it occurs in a much milder way than that of RYGB.

RESUMO Introdução: avaliar as alterações bioquímicas urinárias relacionadas aos processos de litíase urinária após gastrectomia vertical (GV). Método: estudo prospectivo, com 32 indivíduos submetidos a GV, sem diagnóstico prévio de urolitíase. Foi coletada urina de 24 horas, sete dias antes da operação e no retorno de 6 meses. As variáveis estudadas foram volume de urina, pH urinário, oxalato, cálcio, citrato e super saturação de oxalato e cálcio (SS CaOx). Resultados: os pacientes foram em sua maioria mulheres (81,2%), com idade média de 40,6 anos. O IMC médio pré e pós-operatório foi 47,1 ± 8,3 Kg/m2 e 35,5 ± 6,1 Kg/m2, respectivamente (p<0,001). O volume de urina foi significativamente baixo na avaliação pós-operatória em valores absolutos (2.242,50 ± 798,26 mL versus 1.240,94 ± 352,39 mL, p<0,001) e ajustado ao peso corporal (18,58 ± 6,92 mL/kg versus 13,92 ± 4,65 mL/kg, p<0,001). A SS CaOx aumentou significativamente após a GV (0,11 ± 0,10 versus 0,24 ± 0,18, p<0,001). Além disso, os níveis de ácido úrico apresentaram-se significativamente baixos na avaliação pós-operatória (482,34 ± 195,80 mg versus 434,75 ± 158,38 mg, p=0,027). PH urinário, oxalato, cálcio, citrato e magnésio não apresentaram variações significativas entre os períodos pré e pós-operatório. Conclusão: a GV pode levar a alterações importantes no perfil urinário. Entretanto, essas ocorrem de forma muito mais leve que na derivação gástrica em Y de Roux.