Serum uric acid and its association with metabolic syndrome and carotid atherosclerosis in obese children

The Inflammatory and Oxidative Status of Newly Diagnosed Class III and Class IV Lupus Nephritis, with Six-Month Follow-Up

Lupus nephritis (LN) is the most frequent and severe complication of systemic lupus erythematosus (SLE). A prospective cohort with a six-month follow-up was performed. Twelve SLE patients diagnosed with LN Class III, twelve NL Class IV patients, and twelve healthy control subjects (HC) were included. SLE data, renal function, oxidants, antioxidants, and inflammation were determined at baseline and six-month follow-up. During the six-month follow-up, the SLE Disease Activity Index (SLEDAI-2K) decreased in both LN Class III (20.08 ± 6.92 vs. 11.92 ± 5.87, p < 0.001) and LN Class IV (25.33 ± 6.01 vs. 13.83 ± 5.52, p < 0.001) patients. Furthermore, the values of the C4 component also increased during follow-up for LN Class III (25.36 ± 6.34 vs. 30.91 ± 9.22, p = 0.027) and LN Class IV (12.18 ± 3.90 vs. 20.33 ± 8.95, p = 0.008) groups. Regarding inflammation markers, both groups presented decreased C-reactive protein (CRP), but this was only significant for patients with LN class III (7.93 ± 1.77 vs. 4.72 ± 3.23, p = 0.006). Renal function remained stable in both groups, with no changes in eGFR. Patients with LN Class III and Class IV showed higher baseline levels for lipoperoxides (Class III p < 0.01, Class IV p < 0.1) and carbonyl groups in proteins (Class III p < 0.01, Class IV p < 0.1) compared to HC. Moreover, both groups presented lower baseline values of total antioxidant capacity (Class III p < 0.01, Class IV p < 0.1) and catalase (Class III p < 0.01, Class IV p < 0.1) compared to HCs. However, antioxidant and oxidant markers did not show significant differences between baseline values and at six months for either of the two study groups. In conclusion, patients show an imbalance in the oxidative state characterized by the increase in the oxidants LPO and protein carbonyl groups and the decrease in the activity of the antioxidant enzymes TAC and CAT compared to HC. However, the patients did not present an increase in disease activity and renal function improvement. The glomerular filtration rate did not change during the length of the study, and SLEDAI -2K, C3, and C4 improved. The early co-management between Rheumatologists and Nephrologists is essential to prevent the rapid progression of LN. It would be interesting to administer antioxidant supplements to patients with a recent diagnosis of LN and evaluate its effect in a follow-up study.

Factors Affecting Dyslipidemia among Korean Adolescents: An Analysis Using the 8th Korea National Health and Nutrition Examination Survey (2021)

A high prevalence of dyslipidemia has recently been shown not only in adults, but also in adolescents. When occurring in adolescence, dyslipidemia is a risk factor for cardiovascular disease in adulthood. This study aimed to identify significant factors affecting dyslipidemia in South Korean adolescents. We used data from the third year of the 8th Korea National Health and Nutrition Examination Survey (KNHANES VIII-3) on 381 Korean adolescents aged 12-18 years. The data were analyzed using frequency analysis, descriptive statistics, the Rao-Scott χ test, the t-test, and univariate and multivariate logistic regression using complex sample analysis. On a weighted population basis, 28.1% of the adolescents among the participants were identified as the group with dyslipidemia. Obesity, waist circumference, serum uric acid, and alanine aminotransferase (ALT) were significantly related to the prevalence of dyslipidemia. Physical activity 4-7 days a week was related to a decrease in the prevalence of dyslipidemia only in male adolescents. The results of this study can be used as evidence for the risk assessment of adolescent dyslipidemia and the establishment of systematic health management guidelines according to risk factors for the prevention of adolescent dyslipidemia.

Higher serum uric acid is associated with body fat, retinol-binding protein 4, and antioxidative status in Brazilian children

OBJECTIVE

The aim of this study was to evaluate the association of serum uric acid (SUA) with adiposity, adipokines, and anti- and oxidative markers in Brazilian children.

METHODS

This was a cross-sectional investigation with 378 children ages 8 to 9 y in Viçosa, Minas Gerais, Brazil. Information on sociodemographic and lifestyle characteristics was obtained via questionnaires, and body fat was determined by dual energy x-ray absorptiometry. We compared the distributions of adiposity (total and central), adipokines (adiponectin, chemerin, leptin, and retinol-binding protein 4 [RBP4]), anti- and oxidative markers (plasma ferric reducing antioxidant power [FRAP], superoxide dismutase [SOD], and malondialdehyde [MDA]) by SUA categories using linear regression.

RESULTS

SUA was positively associated with total and central fat. Every standard deviation (SD) of SUA was related, respectively, to a 3.4 (95% confidence interval [CI], 2.4-4.4), 4 (95% CI, 2.8-5.1), 4.2 (95% CI, 2.9-5.5), and 3.5 (95% CI, 2.4-4.6) units higher of total, truncal, android, and gynoid fat. We found a positive association of SUA with RBP4 and FRAP, and a negative association with MDA. Every SD of SUA was related, respectively, to 0.1 (95% CI, 0.01-0.1) and 7.8 (95% CI, 5.5-10.1) units higher of RBP4 and FRAP; and to -0.3 (95% CI, -0.5 to -0.1) units lower of MDA.

CONCLUSIONS

SUA was positively associated with adiposity, RBP4, and antioxidative status in Brazilian children.

Unveiling the Silent Danger of Childhood Obesity: Non-Invasive Biomarkers Such as Carotid Intima-Media Thickness, Arterial Stiffness Surrogate Markers, and Blood Pressure Are Useful in Detecting Early Vascular Alterations in Obese Children

Obese children present a higher cardio-metabolic risk. Measuring vascular biomarkers that assess the evolution of arterial stiffness, subclinical atherosclerosis, and hypertension in such patients could be helpful in the long term. We studied 84 children, aged from 6 to 18 years: 50 obese subjects, versus 34 of normal weight. Clinical examination involved: BMI, waist circumference, waist-to-height ratio, and detection of the presence of acanthosis nigricans and irregular menstrual cycles (the latter in adolescent girls). The carotid intima-media thickness (CIMT) was measured with the Aixplorer MACH 30 echography device. The pulse wave velocity (PWV), augmentation index (AIx), and peripheral and central blood pressures (i.e., SBP, DBP, cSBP, cDBP, and cPP) were acquired through a Mobil-O-Graph device. Obese subjects underwent body composition analysis with a Tanita BC-418. Blood tests were: HOMA-IR, lipid panel, uric acid, and 25-OH vitamin D. All vascular biomarkers presented increased values in obese subjects versus controls. The following cut-off values were significant in detecting obesity: for PWV > 4.6 m/s, cSBP > 106 mmHg for the <12-year-olds, PWV > 4.5 m/s and cSBP > 115 mmHg for the 12-15-year-olds, and PWV > 5 m/s, cSBP > 123 mmHg for the >15-year-olds. AIx is higher in obese children, regardless of their insulin resistance status. Waist circumference and waist-to-height ratio correlate to all vascular parameters. HOMA-IR is an independent predictor for all vascular parameters except CIMT. Cut-off values for PWV of >4.8 m/s, SBP > 125 mmHg, and a cSBP > 117 mmHg predicted the presence of acanthosis nigricans. Obese girls with irregular menses displayed significantly higher PWV, SBP, and DPB. Elevated levels of uric acid, LDL-c, non-LDL-c, triglycerides, and transaminases, and low levels of HDL-c and 25-OH vitamin D correlated with higher arterial stiffness and CIMT values. We conclude that CIMT and the markers of arterial stiffness are useful in the early detection of vascular damage in obese children.

Uric acid and sCD163 as biomarkers for metabolic dysfunction and MAFLD in children and adolescents with overweight and obesity

OBJECTIVES

The prevalence of childhood obesity increases globally, and noninvasive methods are needed to identify metabolic dysfunction and obesity-related complications such as pediatric metabolic associated fatty liver disease (MAFLD). We investigated whether uric acid (UA) and the macrophage marker soluble form of cysteine scavenger receptor CD163 (sCD163) can be used as biomarkers for deteriorated metabolism or pediatric MAFLD in children with overweight or obesity.

METHODS

Cross-sectional clinical and biochemical data from 94 children with overweight or obesity was included. Surrogate liver markers were calculated, and correlations were investigated using Pearson's or Spearman's correlation test.

RESULTS

UA and sCD163 correlated with BMI standard deviation score (r=0.23, p<0.05; r=0.33, p<0.01) and body fat (r=0.24, p<0.05; r=0.27, p=0.01). UA correlated with triglycerides (ρ=0.21, p<0.05), fat free mass (r=0.33, p<0.01), and gamma-glutamyl transferase (r=0.39, p<0.01). sCD163 correlated with the pediatric NAFLD fibrosis score (r=0.28, p<0.01) and alanine aminotransferase (r=0.28, p<0.01). No correlation was found between UA and pediatric MAFLD.

CONCLUSIONS

UA and sCD163 was identified as markers of a deranged metabolic profile, thus acting as easily accessible biomarkers for obesity and an obesity-related deranged metabolism. Furthermore, increasing levels of sCD163 could be a useful biomarker of pediatric MAFLD. Future prospective studies are warranted.

Combining body mass index and waist height ratio to assess the relationship between obesity and serum uric acid levels in adolescents

Background

The study aims to explore the relationship between obesity and serum uric acid in adolescents by combining body mass index and waist height ratio.

Methods

475 adolescents in our study were classified as normal weight without central obesity (NW), normal weight but central obesity (NWCO), overweight or obesity without central obesity (OB) and overweight or obesity with central obesity (OBCO). Odds ratios (OR) and 95% confidence intervals (CI) for hyperuricemia were calculated using a logistic regression model. The dose-response association between obesity indicators and serum uric acid were explored by restricted cubic spline model.

Results

The highest serum uric acid level and the OR for hyperuricemia were found in the OBCO group, regardless of sex. After controlling for waist height ratio, the risk of hyperuricemia increased with increasing body mass index in boys and girls. The restricted cubic spline model showed that boys had higher ORs for hyperuricemia at the 25th and 75th percentiles of body mass index than for waist height ratio and girls had a higher OR for hyperuricemia than waist height ratio at the 25th percentile of body mass index.

Conclusions

Hyperuricemia in adolescence was not only associated with the overweight or obesity in BMI, but with the combination of overweight or obesity in BMI and central obesity in WHtR. However, in boys and girls, the increased risk of hyperuricemia associated with elevated body mass index was significantly better than that of waist height ratio.

[Correlation of uric acid with carotid intima media thickness in obese adolescents]

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.

Uric acid versus metabolic syndrome as markers of fatty liver disease in young people with overweight/obesity

AIMS

To compare the association of high serum uric acid (HUA) or metabolic syndrome (MetS) with fatty liver disease (FLD) in youths with overweight/obesity (OW/OB).

MATERIALS AND METHODS

Cross-sectional study of anthropometrics, biochemical variables, and liver ultrasound of 3104 individuals with OW/OB (age 5-17 years). Metabolic syndrome was defined by ≥ 3 criteria among (1) high waist circumference; (2) high triglycerides; (3) low high-density lipoproteins; (4) fasting glucose ≥100 mg/dl; (5) blood pressure ≥95^th percentile in children, and ≥130/80 mmHg in adolescents. High serum uric acid was defined as serum UA value ≥ 75^th percentile adjusted for sex. Fatty liver disease was determined by echography.

RESULTS

The sample was stratified in four categories: (1) no HUA, no MetS (reference category); (2) MetS; (3) HUA; (4) HUA and MetS (HUA + MetS). The prevalence of FLD increased across the four categories from 29.9%, 44.0%, 52.2%, to 67.1%, respectively (p < 0.0001). The ORs for the categorical variables were 1.33 (1.06-1.68) for MetS (p = 0.02), 3.19 (2.51-4.05) for HUA (p < 0.0001) and 3.72 (2.65-5.21) for HUA + MetS (p < 0.0001), versus the reference category regardless of the body mass index.

CONCLUSIONS

HUA represents a useful marker of FLD in youths with OW/OB, given its greater ability to identify those at increased risk of the disease compared to MetS. The ability of both to predict incident FLD must be investigated in longitudinal study.

Assessing 48 SNPs in Hypertensive Paediatric Patients and Young Adults with Review of Genetic Background of Essential Hypertension

Essential hypertension in paediatric patients and young adults is rising, mostly on account of obesity-related hypertension. Clinically, the difference between obese hypertensive and non-obese hypertensive individuals is evident; yet, the pathophysiology of essential and obesity-related hypertension is multifactorial, complex and not fully understood. The aim of our study was to obtain a comprehensive view of the clinical differences between obesity-related hypertension and hypertension in non-obese paediatric patients and young adults and to do genetic tests to possibly highlight some of the pathophysiological differences with a review of their genetic backgrounds. Four hundred and thirty-six hypertensive paediatric patients and young adults were included in the study, and a study of 48 single-nucleotide polymorphisms, using Kompetitive allele specific PCR, was conducted. The subjects were divided into 243 non-obese participants with hypertension and 193 obese participants with hypertension. The data for the clinical comparison of both groups were collected as well. The differences in some clinical and biochemical parameters were confirmed. Genetic tests showed a significant difference in one allele frequency between both groups in five SNPs: rs6232, rs6235, rs12145833, rs59744560 and rs9568856. In rs6235 and rs59744560, a direct effect of different allele states could be implied. Obesity-related hypertension at a young age differs from essential hypertension in those non-obese. The reported genetic differences could be important in understanding the complex pathophysiology of early-onset obesity-related hypertension and should be further evaluated.

Association of Hyperuricemia with 10-Year Atherosclerotic Cardiovascular Disease Risk among Chinese Adults and Elders

The purpose of this cross-sectional study is to use a representative sample of the Chinese population and the atherosclerotic cardiovascular disease (ASCVD) risk assessment tool developed specifically for the Chinese to explore the prevalence of hyperuricemia (HUA) and the relationship between hyperuricemia and 10-year ASCVD risk in Chinese adults. Data was collected from the Chinese Physiological Constant and Health Condition survey. In this study, 12,988 subjects aged between 35 and 74 were selected by two-stage, cluster and random sampling. The sex-specific 10-year ASCVD risk scores equations, which were conducted by China-PAR project and specifically designed for Chinese adults, were used to assess the risk of developing ASCVD 10 years later. The ordinal regression model was used to explore the relationship between hyperuricemia and ASCVD risk. The total prevalence of hyperuricemia was 12.69%, and males’ prevalence was significantly higher than females (17.7% vs. 8.5%). Compared with people without hyperuricemia, the 10-year ASCVD risk scores of female with hyperuricemia increased significantly, but no significant increased happened in male. The ordinal regression model indicated that hyperuricemia subjects were 1.3 (males, 95% CI: 1.11–1.52) and 4.34 (females, 95% CI: 3.16–5.91) times more likely to increase their ASCVD risk levels than those without hyperuricemia. In conclusion, Hyperuricemia is prevalent among Chinese adults. In both genders, hyperuricemia was related with higher risk of 10-year ASCVD, and the relationship is much stronger in females than in males. Thus, sex-specific serum uric acid management and intervention strategies should be done in the prevention and control of cardiovascular events.

An exposome-wide association study on body mass index in adolescents using the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2013-2014 data

Excess weight is a public health challenge affecting millions worldwide, including younger age groups. The human exposome concept presents a novel opportunity to comprehensively characterize all non-genetic disease determinants at susceptible time windows. This study aimed to describe the association between multiple lifestyle and clinical exposures and body mass index (BMI) in adolescents using the exposome framework. We conducted an exposome-wide association (ExWAS) study using U.S. National Health and Nutrition Examination Survey (NHANES) 2003–2004 wave for discovery of associations between study population characteristics and zBMI, and used the 2013–2014 wave to replicate analysis. We included non-diabetic and non-pregnant adolescents aged 12–18 years. We performed univariable and multivariable linear regression analysis adjusted for age, sex, race/ethnicity, household smoking, and income to poverty ratio, and corrected for false-discovery rate (FDR). A total of 1899 and 1224 participants were eligible from 2003–2004 and 2013–2014 survey waves. Weighted proportions of overweight were 18.4% and 18.5% whereas those for obese were 18.1% and 20.6% in 2003–2004 and 2013–2014, respectively. Retained exposure agents included 75 laboratory (clinical and biomarkers of environmental chemical exposures) and 64 lifestyle (63 dietary and 1 physical activity) variables. After FDR correction, univariable regression identified 27 and 12 predictors in discovery and replication datasets, respectively, while multivariable regression identified 22 and 9 predictors in discovery and replication datasets, respectively. Six were significant in both datasets: alanine aminotransferase, gamma glutamyl transferase, segmented neutrophils number, triglycerides; uric acid and white blood cell count. In this ExWAS study using NHANES data, we described associations between zBMI, nutritional, clinical and environmental factors in adolescents. Future studies are warranted to investigate the role of the identified predictors as early-stage biomarkers of increased BMI and associated pathologies among adolescents and to replicate findings to other populations.

Decreased level of soluble receptor activator of nuclear factor-κβ ligand (sRANKL) in overweight and obese children

INTRODUCTION

Childhood obesity contributes to the development of cardiovascular diseases. The molecular pathway - receptor activator of nuclear factor-κβ ligand (RANKL), its receptor RANK and osteoprotegerin (OPG) - takes part not only in bone metabolism but is also involved in the atherosclerosis process. RANKL stimulates osteogenic differentiation and calcification of vascular smooth cells. The associations between the OPG-sRANKL system and various cardiovascular risk factors were displayed. We aimed to evaluate the relationships between serum sRANKL (soluble RANKL) levels and the OPG/sRANKL ratio with cardiometabolic risk factors in overweight and obese children.

MATERIAL AND METHODS

The study included 70 children with overweight and obesity (mean age 13.0 ± 2.8) and 35 age-matched normal weight, healthy peers as a control group. In all patients, anthropometric measurements and laboratory tests were performed. Additionally, an oral glucose tolerance test (OGTT) was made only in overweight and obese children. Atherogenic and insulin resistance indices were calculated.

RESULTS

Overweight and obese children had lower sRANKL levels compared to the control group (median 276.95 vs 325.90, p=0.011), and consequently a higher OPG/sRANKL ratio (0.02 vs 0.01, p = 0.013). The studied children in the lowest quartile of sRANKL levels had higher body weight, Body Mass Index, waist circumference and increased glucose and insulin levels 60 minutes after OGTT and higher uric acid values compared to children in the highest quartile. In multivariable linear regression analysis sRANKL negatively correlated only with uric acid (β = - 0.508, p = 0.041). No association was found for the OPG/sRANKL ratio.

CONCLUSION

Excess fat mass seems to alter the OPG/RANKL ratio mainly by reducing serum sRANKL levels. The correlation between sRANKL and uric acid may suggest a contribution of the OPG-sRANKL system in the cardiometabolic process, but that observation should be confirmed in future studies.

Association between serum uric acid and carotid atherosclerosis in elderly postmenopausal women: A hospital-based study

BACKGROUND

Carotid atherosclerosis (CAS) is associated with increased cardiovascular risk and implicated in 20-30% of strokes.

METHODS

504 patients were included in this study. The detailed medical history and the results of physical examination, carotid ultrasound examination, and routine laboratory tests were collected. Logistic regression analyses were conducted to analyze the relationship between the SUA and the presence of carotid plaques. And the relationship between SUA and the progression of CAS was analyzed by multiple linear regression. The effect of hormone replacement therapy (HRT) on CAS has also be evaluated.

RESULTS

412 patients (81.7%) had carotid plaques of different sizes by carotid ultrasound examination. We found a positive association between the level of SUA and the probability of having carotid plaque by univariate logistic regression (OR: 2.01, 95% CI: 1.83-2.19, p = 0.003). At 2 years post-discharge, we found that 1 mg/dL increase in SUA levels was expected to 0.946% increase in plaque score and 0.026 cm increase in carotid intima-media thickness, separately. Moreover, patients treated by long-term HRT (≥5 years) had a lower level of SUA and blood lipid and the less change of plaque score and carotid intima-media thickness than patients without HRT.

CONCLUSION

The presence and progression of CAS had significantly positive associations with the level of SUA. And the HRT may have the ability to prevent the presence and progression of CAS. However, the safety and long-term outcome of HRT on CAS should be evaluated in further studies.

A practical means of evaluating the prognosis of acute pancreatitis, as measurement of carotid artery intima-media thickness

BACKGROUND AND STUDY AIMS

Factors such as age, obesity, diabetes mellitus and hyperlipidemia that cause adverse prognosis in acute pancreatitis also cause an increase in carotid intima-media thickness. In this study, we aimed to investigate the usability of the measurement of carotid intima-media thickness, which is an easy to apply, cost-effective means of measurement applied to the patients, in predicting AP prognosis, apart from the criteria currently utilized to predict AP prognosis.

PATIENTS AND METHODS

101 patients diagnosed with acute pancreatitis were prospectively enrolled into the study. Right and left common carotid artery intima-media thickness, right and left internal carotid artery intima-media thickness were measured with ultrasonographic images performed within the first 24 hours of hospitalization. local or systemic complications and organ failure development were monitored in the follow-up of the patients.

RESULTS

After the ROC analysis was performed and the threshold value was determined. The patients with main and internal carotid artery intima-media thickness above 0.775 mm were seen to have a more severe AP (p = 0.000). Local and systemic complications and organ failure were also more common in these patients.

CONCLUSIONS

Measurement of carotid intima-media thickness is a non-invasive method that can be used to predict the prognosis in patients with acute pancreatitis at presentation.

Cumulative Serum Uric Acid and Its Time Course Are Associated With Risk of Myocardial Infarction and All-Cause Mortality

Background Serum uric acid (SUA) has been demonstrated as a risk factor for myocardial infarction (MI) and all-cause mortality; however, the impact of cumulative SUA (cumSUA) remains unclear. We aimed to investigate the association of cumSUA with MI risk and all-cause mortality, and to further explore the effects of SUA accumulation time course. Methods and Results The study enrolled 53 463 participants without a history of MI, and these participants underwent 3 examinations during 2006 to 2010. cumSUA from baseline to the third examination was calculated, multiplying mean values between consecutive examinations by time intervals between visits. Cox models estimated hazard ratios (HRs) and 95% CIs of MI and all-cause mortality for cumSUA quartiles, hyperuricemia exposure duration, and SUA accumulation time course. During a median follow-up of 7.04 years, 476 incident MIs and 2692 deaths occurred. In the fully adjusted model, a higher MI risk was observed in the highest cumSUA quartile (HR, 1.48; 95% CI, 1.10-1.99), in participants with longer hyperuricemia exposure duration (HR, 1.71; 95% CI, 1.06-2.73), and in participants with cumSUA≥median and a negative slope (HR, 1.58; 95% CI, 1.18-2.11). Similar associations persisted for all-cause mortality. Conclusions The risk of MI and all-cause mortality increased with higher cumSUA and was affected by the SUA accumulation time course. Early SUA accumulation contributed more to MI risk and all-cause mortality than later SUA accumulation with the same overall cumulative exposure, emphasizing the importance of optimal SUA control early in life.

The relationship between anthropometric factors and hyperuricemia in adolescent athletes

PURPOSE

Hyperuricemia has been increasingly prevalent and linked to future cardio-metabolic risks in adolescent population. The study aims to explore the relationship between anthropometric indices and hyperuricemia among adolescent athletes.

METHODS

This was a cross-sectional study of 387 student athletes (218 males and 169 females; mean age, 17.4 ± 1.3 years) in Northern Taiwan in 2013-2015. We exhibited the prevalence of hyperuricemia among this population, and tested the association of serum uric acid levels with different anthropometric parameters in males and females respectively.

RESULTS

A total of 59 (27.1%) male and 37 (21.8%) female adolescent athletes had hyperuricemia. Both in male and female adolescents, several obesity-related anthropometric parameters were significantly higher in hyperuricemia groups than in non-hyperuricemia groups. The odds of having hyperuricemia significantly increased with increasing BMI, BMI z-score, waist circumference and waist-to-height ratio in logistic regression analysis. There was a U-shaped association between uric acid level and body fat percentage (BF%) in both genders. Subjects whose BF% in lowest-body-fat-percentage quintile (quintile 1) and highest-body-fat-percentage quintile (quintile 5) had higher mean serum uric acid level than subjects whose BF% in the middle three quintiles. In both genders, the odds ratio (OR) of having hyperuricemia in subjects whose BF% in quintile 1 remained significantly higher than the OR in the middle three quintiles (the reference) after adjusting for age and BMI z-score.

CONCLUSIONS

In addition to the positive association between obesity and hyperuricemia, there is a U shape association between BF% and prevalence of hyperuricemia among adolescent athletes of both genders.

Uric acid, impaired fasting glucose and impaired glucose tolerance in youth with overweight and obesity

BACKGROUND AND AIM

The relationships between uric acid (UA) and prediabetes is poorly explored in youth. We investigated the association between UA, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), insulin resistance (IR) and low insulin sensitivity (IS) in youth with overweight/obesity (OW/OB).

METHODS AND RESULTS

A cross-sectional study was performed in 2248 youths with OW/OB (age 5-17 years). The sample was stratified in sex-specific quintiles (Q1 to Q5) of UA and the associations with fasting (FG), 2-h post-load glucose (2H-PG), IR and low IS were investigated. IR and low IS were estimated by assessment model of insulin resistance (HOMA-IR) and whole-body IS index (WBISI), respectively. IFG was defined as FG ≥ 100 < 126 mg/dL, IGT as 2H-PG ≥140 < 200 mg/dL, IR as HOMA-IR ≥75th percentile and low IS as WBISI ≤25th percentile by sex. Age, body mass index z-score, 2H-PG, HOMA-IR and WBISI, increased across sex-quintiles of UA while FG did not. The prevalence of IFG and IR were significantly increased in Q5 vs Q1 (reference quartile, P < 0.025). The prevalence of IGT increased from Q3 to Q5 vs Q1 (P < 0.025-0.0001) and that of low IS from Q2 to Q5 vs Q1 (P < 0.005-0.0001).

CONCLUSIONS

In youth with OW/OB, rates of IGT and low IS increased progressively across quintiles of UA. On the contrary, IFG and IR were associated only with the highest quintile of UA. Our data suggest that UA is a biomarker of impaired glucose metabolism prevalently in post-challenge condition rather than in fasting state.

The ratio of superoxide dismutase to standard deviation of erythrocyte distribution width as a predictor of systemic lupus erythematosus

BACKGROUND

To explore the clinical value of the serum superoxide dismutase-to-standard deviation of erythrocyte distribution width ratio (SRSR) in systemic lupus erythematosus (SLE).

METHODS

A total of 222 SLE patients from the Rheumatology and Immunology Department in the Second Affiliated Hospital of Chongqing Medical University from January 2017 to April 2019 were collected as the experimental group, and a total of 202 healthy physical examiners were extracted as the control group. Neutrophil-to-lymphocyte ratio (NLR), superoxide dismutase-to-standard deviation of erythrocyte distribution width ratio (SRSR), and platelet-to-lymphocyte ratio (PLR) were calculated from the collected data and then compared the level of the above three indexes between the two groups. In addition, we analyzed the association between SRSR and clinically relevant indicators.

RESULTS

We found that the SRSR of SLE patients was significantly lower than healthy control group, by analyzing the receiver operating characteristic (ROC) curve; it revealed that the SRSR had higher specificity and sensitivity than either superoxide dismutase (SOD) or standard deviation of erythrocyte distribution width (RDW-SD) alone. The area under the curve (AUC) for SRSR was significantly larger than either SOD or RDW-SD alone, and the AUC for SRSR was also larger than NLR and PLR. And it was found that SRSR was independently correlated with SLE disease activity through multiple linear regression analysis.

CONCLUSION

SRSR is a useful biomarker for the diagnosis of SLE, and it is of great significance in the clinical application.

Association of serum uric acid concentration with components of pediatric metabolic syndrome: A systematic review and meta-analysis

Background:

Hyperuricemia is implicated in the pathogenesis of inflammatory diseases and metabolic disorders. Metabolic syndrome (MetS) in childhood is one of the most important causes of different noncommunicable diseases in adulthood. This study aimed to systematically review the association between serum uric acid (UA) concentration and components of pediatric MetS.

Materials and Methods:

In this meta-analysis and systematic review, related articles were gathered by searching English databases including PubMed, Web of Science, Scopus, and Google Scholar. We used the following keywords: uric acid, metabolic syndrome, hypertension, fasting blood sugar (FBS), hyperglycemia; the search was limited to English language and included observational and cohort studies performed among children or adolescents. Pooled relative risks (odds ratio [OR]) and corresponding 95% confidence interval (95% CI) were extracted. A random-effect model was used.

Results:

On the basis of 34 eligible studies, the pooled correlation between UA with metabolic components including FBS (r = 0.24, 95% CI = 0.09–0.40), fasting insulin (r = 0.26, 95% CI = 0.15–0.37), and hyperglycemia (r for triglyceride and UA = 0.23, 95% CI = 0.19–0.38) (r for high-density lipoprotein and UA = −0.28, 95% CI = −0.37 to −0.20) was statistically significant. The association of both diastolic blood pressure (DBP) and systolic blood pressure (SBP) was statistically significant with UA (r for SBP and UA = 0.34, 95% CI = 0.24–0.43; r for DBP and UA = 0.18, 95% CI = 0.11–0.25). The OR between risk of abdominal obesity with UA was statistically significant (OR = 2.62, 95% CI = 1.41–3.84).

Conclusion:

Serum UA concentration is associated with major components of the pediatric MetS. Its measurement and control should be underscored in at-risk children and adolescents.

Serum Uric Acid Levels and Risk of Intracranial Atherosclerotic Stenosis: A Cross-Sectional Study

Elevated serum uric acid (SUA) has been reported to be associated with an increased risk of cardiovascular diseases, but the role of SUA in intracranial atherosclerosis remains unclear. To investigate the association between SUA and intracranial atherosclerotic stenosis (ICAS), we evaluated 1522 subjects (305 with ICAS, 1217 without ICAS) with magnetic resonance angiography (MRA). Subjects were classified into ten groups according to the deciles of the SUA level. The rate of ICAS reached a minimum in the seventh decile (6.0-6.3 mg/dL; reference group). After adjusting for confounding factors, multivariate logistic regression analysis demonstrated that both low SUA level (≤ 3.8 mg/dL; OR, 2.34; 95% CI, 1.29-4.39; p = 0.006) and high SUA level (≥ 7.8 mg/dL; OR, 2.10; 95% CI, 1.15-3.92; p = 0.017) conferred greater risk for ICAS. In multivariable analysis with a quadratic model which used SUA as a continuous variable, a U-shaped association between SUA and the rate of ICAS was confirmed (α > 0; p < 0.001). The estimated SUA level associated with the lowest rate of ICAS was 6.2 mg/dL. In conclusion, our findings suggest a U-shaped association between ICAS and SUA.

Study of association of serum uric acid with albuminuria and carotid atherosclerosis in type 2 diabetes mellitus patients

Introduction:

Type 2 diabetes mellitus is a heterogeneous group of metabolic disorders of disturbance of carbohydrate, fat, and protein metabolism causing macrovascular (like coronary artery disease) and microvascular (kidney damage) complications. Microalbuminuria is the first manifestation of injury to glomerular filtration barrier and carotid intima-media thickness (IMT) of common carotid artery serves as an excellent marker for early lesion of atherosclerosis.

Method:

A cross-sectional observational study was carried out over a period of 1.5 years in PGIMER, DR. RML Hospital, New Delhi. Patients with type 2 diabetes mellitus, aged between 35 and 60 years, were investigated for uric acid (UA), urine albumin levels, and common carotid IMT during this period. Patients on drugs that affect serum UA level, patients with acute illness, patients with serum creatinine >1.5 mg/dL, or with coronary artery disease were excluded from study.

Result:

Prevalence of hyperuricemia was found to be high (46%) in type 2 diabetic patients. It was also higher in females (73.7%) than males (25.8%). There was positive correlation between serum UA concentrations with logarithm of urine albumin excretion (P < 0.023) and carotid intima-media thickness (IMT) (P < 0.027). Plaque index also showed a positive correlation with UA (P < 0.019). However, there was no positive correlation with UA and other variable such as age, duration of diabetes, systolic blood pressure, diastolic blood pressure, HbA1c, lipid profiles, urea, and creatinine.

Conclusion:

Serum UA concentration thus serves as an early marker of renal dysfunction and cardiovascular diseases in type 2 diabetic patients.

Hyperuricemia is associated with impaired intestinal permeability in mice

Hyperuricemia is associated with many metabolic diseases. However, the underlying mechanism remains unknown. The gut microbiota has been demonstrated to play significant roles in the immunity and metabolism of the host. In the present study, we constructed a hyperuricemic mouse model to investigate whether the metabolic disorder caused by hyperuricemia is related to intestinal dysbiosis. A significantly increased intestinal permeability was detected in hyperuricemic mice. The difference in microflora between wild-type and hyperuricemic mice accompanies the translocation of gut microbiota to the extraintestinal tissues. Such a process is followed by an increase in innate immune system activation. We observed increased LPS and TNF-α levels in the hyperuricemic mice, indicating that hyperuricemic mice were in a state of low-grade systemic inflammation. In addition, hyperuricemic mice presented early injury of parenteral tissue and disordered lipid metabolism. These findings suggest that intestinal dysbiosis due to an impaired intestinal barrier may be the key cause of metabolic disorders in hyperuricemic mice. Our findings should aid in paving a new way of preventing and treating hyperuricemia and its complications.NEW & NOTEWORTHY Hyperuricemia is associated with many metabolic diseases. However, the underlying mechanism remains unknown. We constructed a hyperuricemic mouse model to explore the relationship between intestinal dysbiosis and metabolic disorder caused by hyperuricemia.

Hyperuricemia in Children and Adolescents: Present Knowledge and Future Directions

Recent evidence suggests that hyperuricemia is an important condition in children and adolescents, particularly in association with noncommunicable diseases. This review aims to summarize our current understanding of this condition in pediatric patients. An analysis of serum uric acid reference values in a healthy population indicates that they increase gradually with age until adolescence, with differences between the sexes arising at about 12 years of age. This information should be taken into consideration when defining hyperuricemia in studies. Gout is extremely rare in children and adolescents, and most patients with gout have an underlying disease. The major causes of hyperuricemia are chronic conditions, including Down syndrome, metabolic or genetic disease, and congenital heart disease, and acute conditions, including gastroenteritis, bronchial asthma (hypoxia), malignant disorders, and drug side effects. The mechanisms underlying the associations between these diseases and hyperuricemia are discussed, together with recent genetic information. Obesity is a major cause of hyperuricemia in otherwise healthy children and adolescents. Obesity is often accompanied by metabolic syndrome; hyperuricemia in obese children and adolescents is associated with the components of metabolic syndrome and noncommunicable diseases, including hypertension, insulin resistance, dyslipidemia, and chronic kidney disease. Finally, strategies for the treatment of hyperuricemia, including lifestyle intervention and drug administration, are presented.

Salivary markers of hepato-metabolic comorbidities in pediatric obesity

BACKGROUND

The pediatric obesity epidemic calls for the noninvasive detection of individuals at higher risk of complications.

AIMS

To investigate the diagnostic role of combined salivary uric acid (UA), glucose and insulin levels to screen noninvasively for metabolic syndrome (MetS) and nonalcoholic fatty liver disease.

METHODS

Medical history, clinical, anthropometric, and laboratory data including serum triglyceride, glucose, insulin, HOMA, HDL-cholesterol, and UA levels of 23 obese children (15 with [St+] and 8 without [St-] ultrasonographic hepatic steatosis) and 18 normal weight controls were considered.

RESULTS

Serum and salivary UA (p < 0.05; R² = 0.51), insulin (p < 0.0001; R² = 0.79), and HOMA (p < 0.0001; R² = 0.79) levels were significantly correlated; however their values tended to be only slightly higher in the obese patients, predominately in [St+], than in the controls. Notably, UA and insulin levels in both fluids increased in parallel to the number of MetS components. After conversion of the z-logit function including salivary/anthropometric parameters in a stepwise logistic regression analysis, a factor of 0.5 allowed for predicting hepatic steatosis with high sensitivity, specificity, and total accuracy.

CONCLUSIONS

Salivary testing together with selected anthropometric parameters helps to identify noninvasively obese children with hepatic steatosis and/or having MetS components.

Obesity-Related Genetic Variants and Hyperuricemia Risk in Chinese Men

Objective: Obesity/metabolic syndrome and hyperuricemia are clinically associated; however, the association of obesity/metabolic syndrome-related genetic variants with hyperuricemia is not clear. Therefore, we assessed this association in Chinese men diagnosed with hyperuricemia in comparison to a non-hyperuricemia group. Methods: We genotyped 47 single nucleotide polymorphisms (SNPs) previously identified to be associated with obesity or metabolic syndrome in 474 adult males (aged ≥ 18 years) using multiplex polymerase chain reaction. Multivariate logistic regression was used to investigate the association between the genetic variations and hyperuricemia. Stratified analyses were applied to further assess the associations. Results: The obesity-related SNP in MSRA rs545854 significantly affected serum uric acid levels. In addition, the G-allele of rs545854 was positively associated with the risk of hyperuricemia [odds ratio (OR) = 2.80, 95% confidence interval (CI) = 1.19-6.64, P = 0.0188]. After adjusting the model for body mass index and central obesity, rs545854 was shown to be an independent factor increasing the risk of hyperuricemia (OR = 2.81, 95%CI = 1.18-6.70, P = 0.0196). Stratified analyses also showed a significant association between rs545854 and hyperuricemia among meat eaters (OR = 2.62, 95%CI = 1.09-6.26, P = 0.0308). Conclusion: The obesity-related SNP rs545854 was correlated with the serum uric acid level and risk of hyperuricemia in a male Chinese population. Therefore, men carrying this SNP could benefit from limiting their meat consumption to prevent hyperuricemia. These findings suggest an underlying genetic link between obesity and hyperuricemia worthy of further exploration.

The Liver in Children With Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) is recognized as an emerging health risk in obese children and adolescents. NAFLD represents a wide spectrum of liver conditions, ranging from asymptomatic steatosis to steatohepatitis. The growing prevalence of fatty liver disease in children is associated with an increased risk of metabolic and cardiovascular complications. NAFLD is considered the hepatic manifestation of Metabolic Syndrome (MetS) and several lines of evidence have reported that children with NAFLD present one or more features of MetS. The pathogenetic mechanisms explaining the interrelationships between fatty liver disease and MetS are not clearly understood. Altough central obesity and insulin resistance seem to represent the core of the pathophysiology in both diseases, genetic susceptibility and enviromental triggers are emerging as crucial components promoting the development of NAFLD and MetS in children. In the present review we have identified and summarizied studies discussing current pathogenetic data of the association between NAFLD and MetS in children.

Novel Insights in the Metabolic Syndrome in Childhood and Adolescence

Metabolic syndrome (MetS) is recognized as an escalating major health risk in adults as well as in children and adolescents. Its prevalence ranges from 6 to 39% depending on the applied definition criteria. To date, there is no consensus on a MetS definition for children and adolescents. However, most authors agree on essential components such as glucose intolerance, central obesity, hypertension, and dyslipidemia; each representing a risk for cardiovascular disease. Recently, associations between MetS and non-alcoholic fatty liver disease, hyperuricemia, and sleep disturbances have emerged. Biomarkers like adipocytokines are a subject of current research as they are implicated in the pathogenesis of the MetS. Epigenetics and gestational programming, especially the role of microRNA, comprise a novel, rapidly developing and promising research focus on the topic of MetS. MicroRNAs are increasingly valued for potential roles in the diagnosis, stratification, and therapeutics of MetS. Early detection of risk factors, screening for metabolic disturbances, and the identification of new therapies are major aims to reduce morbidity and mortality related to MetS. Dietary modification and physical activity are currently the only adopted treatment approaches. Pharmacological therapies and bariatric surgery are still contradictory and, therefore, are only recommended in selected high-risk cases.

Uric acid and cardiovascular disease

Uric acid (UA) is an end product of purine metabolism in humans and great apes. UA acts as an antioxidant and it accounts for 50% of the total antioxidant capacity of biological fluids in humans. When present in cytoplasm of the cells or in acidic/hydrophobic milieu in atherosclerotic plaques, UA converts into a pro-oxidant agent and promotes oxidative stress and through this mechanism participates in the pathophysiology of human disease including cardiovascular disease (CVD). Most epidemiological studies but not all of them suggested the existence of an association between elevated serum UA level and CVD, including coronary heart disease (CHD), stroke, congestive heart failure, arterial hypertension and atrial fibrillation as well as an increased risk for mortality due to CVD in general population and subjects with confirmed CHD. Evidence available also suggests an association between elevated UA and traditional cardiovascular risk factors, metabolic syndrome, insulin resistance, obesity, non-alcoholic fatty liver disease and chronic kidney disease. Experimental and clinical studies have evidenced several mechanisms through which elevated UA level exerts deleterious effects on cardiovascular health including increased oxidative stress, reduced availability of nitric oxide and endothelial dysfunction, promotion of local and systemic inflammation, vasoconstriction and proliferation of vascular smooth muscle cells, insulin resistance and metabolic dysregulation. Although the causality in the relationship between UA and CVD remains unproven, UA may be pathogenic and participate in the pathophysiology of CVD by serving as a bridging mechanism mediating (enabling) or potentiating the deleterious effects of cardiovascular risk factors on vascular tissue and myocardium.

Associations of plasma uric acid and purine metabolites with blood pressure in children: the KOALA Birth Cohort Study

OBJECTIVE

Elevated serum uric acid concentration has been associated with high blood pressure (BP) and hypertension. A putative underlying mechanism is the accumulation of reactive oxygen species when uric acid is generated by an increased enzyme activity of xanthine oxidase (XO). The aims of the present study were to investigate the associations between plasma uric acid concentration, purine metabolite ratios, as proxies for increased XO activity, and SBP and DBP in school-age children.

METHODS

Cross-sectional analyses were performed in 246 children (46% boys; mean age 7.1 years) from the Dutch KOALA Birth Cohort Study. Purine metabolites were determined with ultra-performance liquid chromatography-tandem mass spectrometry. During a home visit, a nurse collected a blood sample and measured BP three times; in addition, parents measured their child's BP on three consecutive days, in the morning and evening. Generalized estimating equations were used for analyses while controlling for variables such as sex, age, BMI, physical activity, and dietary intake.

RESULTS

In multivariable analysis, uric acid (per SD of 38 μmol/l) was associated with DBP z-scores [sβ 0.07; confidence interval (CI), 0.01-1.14], but not with SBP z-scores. Higher ratios of uric acid/xanthine (per SD of 138) (sβ 0.09; CI, 0.01-0.17) and xanthine/hypoxanthine (per SD of 321) (sβ 0.08; CI, 0.02-0.17) were associated with higher DBP z-scores, but not with SBP z-scores.

CONCLUSION

In school-age children, uric acid and the ratios of uric acid/xanthine and xanthine/hypoxanthine were significantly associated with DBP z-scores. Suggesting that, both uric acid concentration and increased XO activity are associated with BP.

Effects of Sodium Glucose Cotransporter-2 Inhibitors on Serum Uric Acid in Type 2 Diabetes Mellitus

Hyperuricemia has been linked to metabolic syndrome, cardiovascular disease, and chronic kidney disease. Hyperuricemia and type 2 diabetes mellitus were inter-related, type 2 diabetes mellitus was more at risk of having a higher serum uric acid level, and also individuals with higher serum uric acid had higher risk of developing type 2 diabetes in the future. Insulin resistance seems to play an important role in the causal relationship between metabolic syndrome, type 2 diabetes, and hyperuricemia. Oral diabetic drugs that would have additional beneficial effects on reducing serum uric acid levels are of importance. Selective SGLT2 inhibitors were extensively studied in type 2 diabetes mellitus and were found to have improvement of glycemic control, in addition to their proven metabolic effects on weight and blood pressure. Additional beneficial effect of SGLT2 inhibitors on serum uric acid level reduction is investigated. Recently, data have been accumulating showing that they have additional beneficial effects on serum uric acid reduction. As for the postulated mechanism, serum uric acid decreased in SGLT2 inhibitor users as a result of the increase in the urinary excretion rate of uric acid, due to the inhibition of uric acid reabsorption mediated by the effect of the drug on the GLUT9 isoform 2, located at the collecting duct of the renal tubule.

Association between serum uric acid and metabolic syndrome components in prepubertal obese children (Tanner Stage I) from Nuevo León, Mexico - a preliminary study

BACKGROUND

Metabolic syndrome (MetS) is a major risk factor for cardiovascular disease and diabetes. Previous studies in obese children demonstrating a positive association between serum uric acid (sUA) and components of MetS are confounded by lack of uniformity in age and pubertal status of children. Therefore, we have examined the role of sUA in MetS and its components in pre-pubertal children (Tanner Stage I, age ≤ 9 years).

METHODS

Pre-pubertal obese children (32 boys, 27 girls, age 6-9 years) were recruited from Nuevo Leon, Mexico. For comparison, an equal number of children with normal body mass index (BMI) in the same age range (22 Boys, 39 girls, age 6-9 years) were also recruited from the same community. Presence of MetS and its components was defined according to the criteria of International Diabetes Federation. Fasting blood was analyzed for lipids, glucose, insulin, and uric acid.

RESULTS

Among the obese children, sUA was positively associated with insulin resistance and hypertriglyceridemia and negatively associated with high density lipoprotein-cholesterol (HDLc). Subjects were three times more likely to have a MetS diagnosis per one unit (md/dL) difference in sUA. Of the 59 obese pre-pubertal children, 20 were classified as having MetS defined by the presence of abdominal obesity and two or more of other components described under methods. Of these, 57.1% (20/61) had sUA between 5.1 and 7.1 mg/dl.

CONCLUSIONS

The findings of this study clearly indicate a positive relationship between uric acid and MetS and its components in pre-pubertal obese children with Tanner stage I and ≤9 years of age.

Percentiles of serum uric acid and cardiometabolic abnormalities in obese Italian children and adolescents

BACKGROUND

To investigate the association of serum uric acid (SUA) with cardiometabolic abnormalities in Caucasian overweight/obese children (<10 years of age) versus adolescents (≥10 years of age) by drawing age and gender specific percentiles of uric acid.

METHODS

Cross-sectional evaluation of 1364 Caucasian overweight/obese patients (age 4.1-17.9 years; 726 males, 53%; 560 children, 41%).

RESULTS

SUA levels were significantly lower in children than in adolescents (4.74 ± 1.05 vs. 5.52 ± 1.49 mg/dl, p < 0.001) and peaked in 12-14 years-old boys and 10-12 years-old girls. In children with levels of SUA in the highest quartile (N = 75, 13%), OR for high triglycerides was 4.145, 95% CI 1.506-11.407 (p = 0.009). In adolescents with SUA in the highest quartile (N = 274, 34%), ORs for insulin resistance was 2.399 (95%CI 1.4-4.113; p < 0.001); for impaired fasting glucose 2.184 (95% CI 0.877-5.441; p = 0.07); for impaired glucose tolerance 2.390 (95% CI 1.405-4.063; p = 0.001); and for high triglycerides 1.8, (95%CI 0.950-3.420; p = 0.05). Multivariable random-effect linear regression models demonstrated that waist circumference and age (p < 0.0001 for both) are the variables most significantly predicting SUA levels, followed by triglycerides (p = 0.005) and 2 h glucose (p = 0.03) while HOMA-IR and BMI z-score did not predict SUA.

CONCLUSIONS

High uric acid is associated with metabolic abnormalities and particularly with waist circumference very early in childhood.

Uric acid, carotid intima-media thickness and body composition in prepubertal children

BACKGROUND

Increased uric acid is an independent biomarker for cardiovascular disease in obese adolescents and adults.

OBJECTIVE

We investigated whether uric acid relates to carotid intima-media thickness (cIMT) in prepubertal children, and whether body mass index (BMI) and preperitoneal fat modulate this association.

METHODS

359 asymptomatic prepubertal Caucasian children were stratified according to BMI categories (171 with BMI-SDS < 0; 188 with BMI-SDS ≥ 0) and according to preperitoneal fat levels (180 with preperitoneal fat <50th centile; 179 with preperitoneal fat >50th centile). Uric acid levels, insulin resistance (homeostasis model assessment insulin resistance; HOMA-IR), C-reactive protein (CRP), triacylglycerol (TG), systolic blood pressure (SBP), abdominal fat and cIMT (both by ultrasound) were assessed.

RESULTS

Uric acid was associated with several cardiovascular risk factors, namely higher HOMA-IR, CRP, TG, BMI, waist, SBP, preperitoneal fat and cIMT (all P < 0.001 to P < 0.0001). Significant BMI and preperitoneal fat interactions were documented in the relationship between uric acid and cIMT (both P < 0.05), as uric acid was preferentially related to cIMT in heavier children (β = 0.247, P < 0.001, r(2)  = 9.1%) and in children with more preperitoneal fat (β = 0.263, P < 0.0001, r(2)  = 11.9%).

CONCLUSIONS

Serum uric acid is associated with cIMT in asymptomatic prepubertal children. Both higher BMI and preperitoneal fat aggravate the potential risk of atherosclerotic disease imposed by higher concentrations of uric acid.

Clinical Scenario of the Metabolic Syndrome

The term metabolic syndrome (MeS) refers to a cluster of associated symptoms composed of impaired fasting glucose, abdominal obesity, hypertension, and dyslipidemia. MeS is associated with an increased risk of cardiovascular and diabetes-associated morbidity and mortality. The increased amount of visceral fat together with a chronic inflammatory state predisposes to the development of arteriosclerosis. Furthermore, insulin resistance (IR) and dyslipidemia are associated with fatty liver disease. In addition, MeS is linked to non-cardiovascular diseases such as cancer as well as psychiatric or endocrine disorders. Here, we discuss the clinical impact of MeS in cardiovascular and non-cardiovascular diseases to highlight the importance of prevention, early diagnosis, and multifactorial treatment of high-risk individuals.

Novelty in hypertension in children and adolescents: focus on hypertension during the first year of life, use and interpretation of ambulatory blood pressure monitoring, role of physical activity in prevention and treatment, simple carbohydrates and uric acid as risk factors

The present article intends to provide an update of the article "Focus on prevention, diagnosis and treatment of hypertension in children and adolescents" published in 2013 (Spagnolo et al., Ital J Pediatr 39:20, 2013) in this journal. This revision is justified by the fact that during the last years there have been several new scientific contributions to the problem of hypertension in pediatric age and during adolescence. Nevertheless, for what regards some aspects of the previous article, the newly acquired information did not require substantial changes to what was already published, both from a cultural and from a clinical point of view. We felt, however, the necessity to rewrite and/or to extend other parts in the light of the most recent scientific publications. More specifically, we updated and extended the chapters on the diagnosis and management of hypertension in newborns and unweaned babies, on the use and interpretation of ambulatory blood pressure monitoring, and on the usefulness of and indications for physical activity. Furthermore, we added an entirely new section on the role that simple carbohydrates (fructose in particular) and uric acid may play in the pathogenesis of hypertension in pediatric age.

Importance of cystatin C and uric acid levels in the association of cardiometabolic risk factors in Japanese junior high school students

BACKGROUND

Serum cystatin C (CysC), a novel marker of renal function, is associated with the components of metabolic syndrome in adults. Little is known about the utility of CysC and its association with cardiometabolic risks in young subjects.

METHODS AND RESULTS

In a cohort of 454 Japanese junior high school students, the distribution of serum CysC levels and associated variables were analyzed. CysC levels were significantly higher in boys than in girls (0.92±0.10mg/L vs. 0.77±0.08mg/L, p<0.001). CysC was significantly correlated with serum creatinine (r=0.473, p<0.001), and serum uric acid (SUA) (r=0.546, p<0.001). Multivariable regression analysis revealed significant associations between CysC and SUA in all subjects (β=0.241, p<0.001), and in boys and girls separately (β=0.264 and 0.240, respectively, both p<0.001). Importantly, subjects with elevation of both serum CysC and SUA levels had the highest ratio of triglyceride to high-density lipoprotein cholesterol.

CONCLUSIONS

CysC had significant associations with both creatinine and SUA in Japanese junior high school students. The concomitant elevation of serum CysC and SUA levels was associated with subclinical lipid metabolism dysregulation, and suggested the presence of cardiometabolic risk accumulation.

Models Predictive of Metabolic Syndrome Components in Obese Pediatric Patients

BACKGROUND AND AIMS

Components of metabolic syndrome (MetS) are complications caused by abdominal obesity and insulin resistance (IR). Diagnosis of MetS by clinical indicators could help to identify patients at risk of cardiovascular disease and type 2 diabetes. We undertook this study to propose predictive indicators of MetS in obese children and adolescents.

METHODS

A cross-sectional study was carried out. After obtaining informed consent and the registration of the study with an institutional research committee, 172 obese patients from an Obesity Clinic, aged 6-15 years, were included. Variables included were waist circumference (WC), glucose, high-density lipoprotein (HDL), triglycerides (TGL), blood pressure, insulin resistance (by homeostatic model assessment HOMA-index), acanthosis nigricans (AN), uric acid, serum glutamic oxaloacetic transaminase (GOT) and alanine transaminase, and hepatic sonogram. International standards for age and sex variables were used. Multivariate analysis was applied.

RESULTS

Variables predicted components of MetS in children: HOMA-IR (insulin resistance by HOMA index) was increased by 2.4 in hepatic steatosis, by 0.6 for each unit of SUA (serum uric acid), and by 0.009 for every mg/dL of triglycerides. In adolescents, every cm of waist circumference increased systolic blood pressure by 0.6 mmHg, and each unit of SUA increased it by 2.9 mmHg.

CONCLUSIONS

Serum uric acid and waist circumference are useful and accessible variables that can predict an increased risk of cardiovascular disease in obese pediatric patients.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

Urinary polycyclic aromatic hydrocarbons and measures of oxidative stress, inflammation and renal function in adolescents: NHANES 2003-2008

OBJECTIVE

Recent evidence has suggested that polycyclic aromatic hydrocarbons (PAHs) may contribute to cardiometabolic and kidney dysfunction by increasing oxidative stress, but little is known about impacts in childhood.

STUDY DESIGN

We performed cross-sectional analyses of 660 adolescents aged 12-19 years in the 2003-2008 National Health and Nutrition Examination Survey (NHANES), using levels of 10 monohydroxylated urinary PAH metabolites as our exposure. Our primary outcomes of interest were biomarkers of oxidative stress and renal function, including estimated glomerular filtration rate (eGFR), urinary albumin to creatinine ratio (ACR), insulin resistance, and serum uric acid, gamma glutamyl transferase (GGT) and C-reactive protein (CRP).

RESULTS

We observed statistically significant associations between PAH metabolites and levels of serum GGT, CRP, uric acid and eGFR. Each 100% increase in 2-hydroxyphenanthrene was related to a 3.36% increase in uric acid (95% CI: 0.338-6.372; p=0.032), a 3.86% increase in GGT (95% CI: 1.361-6.362; p=0.005) and a 16.78% increase in CRP (95% CI: 1.848-31.689; p=0.029). Each 100% increase in 4-hydroxyphenanthrene was associated with a 6.18% increase in GGT (95% CI: 4.064-8.301; p<0.001) and a 13.66% increase in CRP (95% CI: 2.764-24.564; p=0.017). Each 100% increase in 9-hydroxyfluorene was associated with a 2.58% increase in GGT (95% CI: 0.389-4776; p=0.024). Each 100% increase in 3-hydroxyphenanthrene was associated with a 2.66% decrease in eGFR (95% CI: -4.979 to -0.331; p=0.028).

CONCLUSIONS

Urinary PAH metabolites were associated with serum uric acid, GGT and CRP, suggesting possible impacts on cardiometabolic and kidney function in adolescents. Prospective work is needed to investigate the potential long-term health consequences of these findings.

Hematological parameters in adolescents with hyperuricemia

OBJECTIVE

To examine the association between hematological indices and serum uric acid in adolescents with hyperuricemia.

METHODS

10-year retrospective cohort study of 607 patients with hyperuricemia registered with the Pediatric Nephrology Department.

RESULTS

There was a statistically significant positive correlation between serum uric acid levels and BMI Z-scores (r=0.406, P<0.001), white and red blood cell counts, hemoglobin and hematocrit. Higher levels of hemoglobin, hematocrit and red blood cells were found in adolescents with metabolic syndrome than in groups without this condition.

CONCLUSION

Hematological parameters could be important biological markers of cardiometabolic risk in adolescents with hyperuricemia.

[Hyperuricaemia and metabolic syndrome in obese children and adolescents]

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.

Pathophysiology of hypertension in obese children: a systematic review

Hypertension is increasingly common in overweight and obese children. The mechanisms behind the development of hypertension in obesity are complex, and evidence is limited. In order to effectively treat obese children for hypertension, it is important to have a deeper understanding of the pathophysiology of hypertension in obese children. The present review summarizes the main factors associated with hypertension in obese children and discusses their potential role in its pathophysiology. Systematic searches were conducted in PubMed and EMBASE for articles published up to October 2014. In total, 60 relevant studies were included. The methodological quality of the included studies ranged from weak to strong. Several factors important in the development of hypertension in obese children have been suggested, including endocrine determinants, such as corticosteroids and adipokines, sympathetic nervous system activity, disturbed sodium homeostasis, as well as oxidative stress, inflammation and endothelial dysfunction. Understanding the pathophysiology of hypertension in overweight and obese children is important and could have implications for its screening and treatment. Based on solely cross-sectional observational studies, it is impossible to infer causality. Longitudinal studies of high methodological quality are needed to gain more insight into the complex mechanisms behind the development of hypertension in obese children.

Association of serum uric acid levels to inflammation biomarkers and endothelial dysfunction in obese prepubertal children

BACKGROUND

High serum uric acid (SUA) levels are present in patients with metabolic syndrome (MetS), when the latter is associated with endothelial dysfunction, inflammation, and hypertension. This increase in SUA levels may have a key role in cardiovascular diseases.

OBJECTIVE

We aim to quantify the differences in inflammation biomarkers, endothelial dysfunction, and parameters associated with MetS in obese prepubertal children compared to non-obese children, and determine if there is a relationship between uric acid levels and these variables.

METHODS

A cross-sectional study was carried out on obese children (6-9 yr old). The study included 43 obese children and the same number of non-obese children (control group), matched by age and sex. SUA, C-reactive protein (CRP), interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), glucose, insulin, lipid profile, and blood pressure were all measured.

RESULTS

SUA levels, CRP, and sICAM-1 were significantly higher in obese children. In the obese group, SUA levels showed a positive correlation with body mass index (BMI), insulin, homeostasis model assessment for insulin resistance (HOMA-IR), CRP, IL-6, sICAM-1, and triglycerides (TGs), and correlated negatively with high-density lipoprotein cholesterol (HDL-C) and Apo-AI, but not with Apo-B. When adjusted for age, sex, and creatinine, it was noted that SUA levels are independent predictive factors for sICAM-1, CRP, and IL-6.

CONCLUSIONS

Inflammation biomarkers, endothelial dysfunction, and parameters associated with MetS are elevated in obese prepubertal children and correlate to uric acid levels.

[The role of uric acid in the insulin resistance in children and adolescents with obesity]

Objective:

To investigate the association between serum uric acid levels and insulin resistance in children and adolescents with obesity.

Methods:

Cross-sectional study with 245 children and adolescents (134 obese and 111 controls), aged 8-18 years. The anthropometric variables (weight, height and waist circumference), blood pressure and biochemical parameters were collected. The clinical characteristics of the groups were analyzed by t-test or chi-square test. To evaluate the association between uric acid levels and insulin resistance the Pearson's test and logistic regression were applied.

Results:

The prevalence of insulin resistance was 26.9%. The anthropometric variables, systolic and diastolic blood pressure and biochemical variables were significantly higher in the obese group (p<0.001), except for the high-density-lipoprotein cholesterol. There was a positive and significant correlation between anthropometric variables and uric acid with HOMA-IR in the obese and in the control groups, which was higher in the obese group and in the total sample. The logistic regression model that included age, gender and obesity, showed an odds ratio of uric acid as a variable associated with insulin resistance of 1.91 (95%CI 1.40-2.62; p<−0.001).

Conclusions:

The increase in serum uric acid showed a positive statistical correlation with insulin resistance and it is associated with and increased risk of insulin resistance in obese children and adolescents.

Elevated levels of plasma uric acid and its relation to hypertension in arsenic-endemic human individuals in Bangladesh

Blood uric acid has been recognized as a putative marker for cardiovascular diseases (CVDs). CVDs are the major causes of arsenic-related morbidity and mortality. However, the association of arsenic exposure with plasma uric acid (PUA) levels in relation to CVDs has not yet been explored. This study for the first time demonstrated the associations of arsenic exposure with PUA levels and its relationship with hypertension. A total of 483 subjects, 322 from arsenic-endemic and 161 from non-endemic areas in Bangladesh were recruited as study subjects. Arsenic concentrations in the drinking water, hair and nails of the study subjects were measured by inductively coupled plasma mass spectroscopy. PUA levels were measured using a colorimetric method. We found that PUA levels were significantly (p<0.001) higher in males and females living in arsenic-endemic areas than those in non-endemic area. Arsenic exposure (water, hair and nail arsenic) levels showed significant positive correlations with PUA levels. In multiple regression analyses, arsenic exposure levels were found to be the most significant contributors on PUA levels among the other variables that included age, body mass index, blood urea nitrogen, and smoking. There were dose-response relationships between arsenic exposure and PUA levels. Furthermore, diastolic and systolic blood pressure showed significant positive correlations with PUA levels. Finally, the average PUA levels were significantly higher in the hypertensive group than those in the normotensive group in both males and females living in arsenic-endemic areas. These results suggest that arsenic exposure-related elevation of PUA levels may be implicated in arsenic-induced CVDs.

The metabolite profiles of the obese population are gender-dependent

Studies have identified that several amino acids, in particular, branched-chain amino acids (BCAAs), have increased significantly in obese individuals when compared to lean individuals. Additionally, these metabolites were strongly associated with future diabetes, which rendered them prognostic markers suitable for obese populations. Here we report a metabonomic study that reveals new findings on the role of these amino acid markers, particularly BCAAs, in a Chinese cohort including 106 healthy obese and 105 healthy lean participants. We found that the BCAAs were correlated with insulin resistance and differentially expressed in obese men, but not in obese women. The results were verified with two independent groups of participants (Chinese, n = 105 and American, n = 72) and demonstrate that the serum metabolite profiles of the obese population are gender-dependent. The study supports the previous findings of a panel of several key metabolites as prognostic markers of the obese population and highlights the need to take into account gender differences when using these markers for risk assessment.

Children with Down's syndrome display high rates of hyperuricaemia

AIM

Several studies show that hyperuricaemia, abnormally high levels of uric acid in the blood, frequently occurs in adult Down's syndrome patients, but paediatric research is scarce. We aimed to clarify its prevalence in paediatric Down's syndrome patients and its association with lifestyle-related laboratory variables and nutritional intake, to consider possible effects in later life.

METHODS

We compared 52 Down's syndrome patients, from one to 15 years of age, with age-matched controls. Hyperuricaemia was defined using reference values established for children, as uric acid z-scores of more than 2.0. Nutritional intake was estimated using 3-day dietary records.

RESULTS

Hyperuricaemia occurred in 17 Down's patients (32.7%) and was significantly higher in Down's patients than the controls. The prevalence was also significantly higher in males. There were no significant differences between hyperuricaemia-positive and hyperuricaemia-negative patients in terms of age, body mass index standard deviation scores, fasting blood glucose, insulin, homeostasis model assessment-insulin resistance and triglyceride, and purine body intake was similar. There were differences in high-density lipoprotein cholesterol.

CONCLUSION

We found high rates of hyperuricaemia from early childhood in Down's syndrome patients. This suggests careful management of Down's syndrome patients, as hyperuricaemia is an independent risk factor for lifestyle-related diseases in adulthood.