Serum uric acid in Korean children and adolescents: reference percentiles and association with metabolic syndrome

Association of serum uric acid Levels with metabolic syndromes in Korean adolescents

Introduction

The study findings investigated uric acid reference values and their association with a cluster of cardiometabolic risk factors among adolescents using the Korea National Health and Nutrition Examination Survey (KNHANES).

Methods

A retrospective cross-sectional study was conducted using the KNHANES database from 2016 to 2018, involving a total of 2,462 participants aged between 10 and 18 years. Based on age- and sex-specific percentile curves for serum uric acid (SUA) levels from the KNHANES, we examined the correlation between cardiometabolic risk factors and serum uric acid levels.

Results

The percentile values of SUA varied with sex and age. In male subjects, SUA levels tended to increase from 10 to 14 years of age and plateaued after 14 years of age. Moreover, the overall uric acid level in females was found to be lower than that in males; the levels tended to increase at approximately 10 to 12 years old but were relatively consistent according to age. Mean uric acid levels increased according to obesity status in both males and females. However, correlation analysis revealed that SUA levels were associated with several metabolic risks even after adjusting for obesity. The detailed metabolic syndrome (MetS) components that were observed to be associated with an increase in uric acid levels were different between males and females, but overall, high uric acid levels increased MetS risk. Additionally, a significant increase in MetS-related odds ratio (OR) for components, including waist circumference (WC), triglyceride (TG) levels, and low high-density lipoprotein cholesterol (HDL-c), was observed. However, differences between sexes were apparent, with a more pronounced increase in OR based on SUA levels in girls.

Discussion

SUA levels were closely associated with MetS and its components, even in nonobese subjects. Therefore, high SUA levels in children and young adolescents should be closely monitored to prevent MetS.

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.

Skeptical Look at the Clinical Implication of Metabolic Syndrome in Childhood Obesity

Metabolic syndrome (MetS) is defined by a cluster of several cardio-metabolic risk factors, specifically visceral obesity, hypertension, dyslipidemia, and impaired glucose metabolism, which together increase risks of developing future cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). This article is a narrative review of the literature and a summary of the main observations, conclusions, and perspectives raised in the literature and the study projects of the Working Group of Childhood Obesity (WGChO) of the Italian Society of Paediatric Endocrinology and Diabetology (ISPED) on MetS in childhood obesity. Although there is an agreement on the distinctive features of MetS, no international diagnostic criteria in a pediatric population exist. Moreover, to date, the prevalence of MetS in childhood is not certain and thus the true value of diagnosis of MetS in youth as well as its clinical implications, is unclear. The aim of this narrative review is to summarize the pathogenesis and current role of MetS in children and adolescents with particular reference to applicability in clinical practice in childhood obesity.

Trends in serum uric acid levels among Korean children and adolescents between 2016 and 2020: a nationwide study

The aim of this study was to examine trends in serum uric acid (SUA) levels over a recent 5-year period according to age, sex, obesity, and abdominal obesity among Korean children and adolescents. We conducted a serial cross-sectional analysis using nationally representative data from the Korea National Health and Nutritional Examination Survey from 2016 to 2020. The study outcome was trends in SUA levels. SUA trends were analyzed by survey-weighted linear regression analysis considering the survey year as a continuous variable. SUA trends were also analyzed for subgroups based on age, sex, abdominal obesity, or obesity. This study included 3,554 children and adolescents aged 10-18 years. SUA increased significantly over the study period in boys (p for trend = 0.043), but not in girls (p for trend = 0.300). In age-specific analyses, SUA increased significantly in the 10-12 years group (p for trend = 0.029). After adjusting for age, SUA increased significantly in the obese group of both boys (p for trend = 0.026) and girls (p for trend = 0.023), but not in the overweight, normal, or under-weight groups of either sex. After adjusting for age, SUA increased significantly in the abdominal obesity group of boys (p for trend = 0.017) and girls (p for trend = 0.014), but not in the non-abdominal obesity group of either sex.   Conclusion: In the current study, SUA levels significantly increased in both boys and girls with obesity or abdominal obesity. Further studies of the effect of SUA on health outcomes in boys and girls with obesity or abdominal obesity are needed. What is Known: • High serum uric acid (SUA) is a risk factor for various metabolic diseases, including gout, hypertension, and type 2 diabetes. What is New: • SUA levels increased in boys and the 10-12 years group of Korean children and adolescents. • SUA levels increased significantly in Korean children and adolescents with obesity or central obesity.

Association between the uric acid to high density lipoprotein cholesterol ratio and alanine transaminase in Chinese short stature children and adolescents: A cross-sectional study

Objective

Uric acid to high-density lipoprotein cholesterol ratio (UHR), the ratio of uric acid to high-density lipoprotein cholesterol, is a newly proposed marker of metabolic abnormalities. There are few previous studies directly investigating the relationship between UHR and alanine aminotransferase (ALT), especially in short stature populations, however, short stature children and adolescents are more likely to have metabolic disorders. This research aimed to investigate the relationship between the UHR and ALT in children and adolescents with short stature.

Methods

In this cross-sectional analysis, the clinical data of 1,510 children with height below -2 SD who were evaluated at the Department of Endocrinology, Affiliated Hospital of Jining Medical University from 1 March 2013 to 31 December 2021, were selected. Anthropometric and biochemical indicators were measured. The relationship between UHR and ALT was analysed.

Results

The univariate analysis results showed that UHR was positively associated with ALT (β = 0.43, P < 0.0001). Furthermore, after adjusting for possible confounding factors, a non-linear relationship was detected between UHR and ALT through smooth curve fitting, and the inflection point of UHR was 10.93% after multivariate piecewise linear regression analysis. ALT increased with UHR elevation when the UHR was greater than 10.93% (β = 0.69, 95% CI 0.39, 0.98; P < 0.0001). However, we did not observe a significant relationship when the UHR was less than 10.93% (P = 0.9229).

Conclusion

Our study demonstrated that in Chinese children and adolescents with short stature, UHR may be associated with the regulation of ALT levels, and this relationship merits further investigation.

Comparison between School-Age Children with and without Obesity in Nutritional and Inflammation Biomarkers

Childhood obesity is a major health problem. We examined differences between children with obesity and normal weight in nutritional and inflammation biomarkers. A cross-sectional study was conducted among healthy children aged 10-12 years from Arab villages in Israel. Parents were interviewed regarding sociodemographic and children's health status. Body weight and height measurements were performed and weight categories were defined using the 2007 WHO growth curves. Blood samples were tested for complete blood count, levels of iron, ferritin, lipids, uric acid, and C-reactive protein (CRP). Overall, 146 children (59.0% males, mean age = 11.3 [SD = 0.5]) were enrolled. In total 43.8%, 14.1% and 42.3% of the participants had normal weight, overweight and obesity, respectively. A multivariable logistic regression model showed that children with overweight and obesity had lower iron, and HDL-C levels than children with normal weight. Levels of CRP, uric acid, LDL-C and lymphocytes were higher among children with overweight and obesity. In conclusion, our findings highlight the worse metabolic and nutritional status in overweight and obese children. Such markers play a role in metabolic syndrome, thus suggesting that metabolic syndrome might start in childhood.

Prevalence and Correlates of Metabolic Syndrome and Its Components in Chinese Children and Adolescents Aged 7–17: The China National Nutrition and Health Survey of Children and Lactating Mothers from 2016–2017

This descriptive study aimed to determine the prevalence of metabolic syndrome (MetS) and its components among Chinese children and adolescents aged 7–17 from 2016–2017 according to the Cook’s criteria modified for age on the basis of the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) and to evaluate the associations between the factors of interest (especially vitamin A, vitamin D and hyperuricemia) of MetS and its components, using data from the China National Nutrition and Health Survey of Children and Lactating Mothers from 2016–2017. A total of 54,269 school-aged children and adolescents were ultimately included in this study. Anthropometric measurements and laboratory examinations of the subjects and their relevant information were also collected. A multivariate logistic regression analysis model was applied to analyze the relationships between relevant factors associated with MetS and its components. In the present study, the prevalence of MetS in children and adolescents was 5.98%. Among the five components of MetS, elevated blood pressure (BP) and abdominal obesity were the most prevalent (39.52% and 17.30%), and 58.36% of the subjects had at least one of these components. In the multivariate logistic regression, an overweight condition, obesity and hyperuricemia were positively correlated with the incidence of MetS and all five components. There was also a positive association observed between vitamin A and the risk of MetS and some components of MetS (abdominal obesity and high triglycerides (TG)) and vitamin A was negatively associated with the risk of low high-density lipoprotein cholesterol (HDL-C). Subjects with vitamin D inadequacy had a higher risk of MetS (OR = 1.364, 95%CI: 1.240–1.500) and four of its components, excepting elevated FBG (fast blood glucose). Vitamin D deficiency was positively associated with MetS (OR = 1.646, 95%CI: 1.468–1.845) and all five of its components. Well-designed, large-scale prospective studies are also needed in the future.

Relationship between bisphenol A, bisphenol S, and bisphenol F and serum uric acid concentrations among school-aged children

Background

Hyperuricemia has a suspected relationship with hypertension, metabolic syndrome, kidney disease, and cardiovascular disease. Endocrine disruptors may affect uric acid metabolism; however, few epidemiologic studies have been performed in children regarding newly developed bisphenol A (BPA) substitutes. We evaluated the associations between BPA, bisphenol S (BPS), and bisphenol F (BPF) exposure and serum uric acid concentrations in 6-year-old Korean children.

Methods

From the Environment and Development of Children cohort study, six-year-old children (N = 489; 251 boys) who underwent an examination during 2015–2017 were included. Anthropometry, questionnaires, and biological samples were evaluated. BPA, BPS, and BPF levels were measured from spot urine samples, and log-transformed or categorized into groups for analysis. We constructed linear regression models adjusting for age, sex, urinary creatinine levels, body mass index z-scores, and estimated glomerular filtration rates.

Results

Mean serum uric level was 4.2 mg dL^-1 (0.8 SD) without sex-differences. Among the three bisphenols, higher BPS exposure was associated with increased serum uric acid concentrations (P-value for trend = 0.002). When BPS levels were categorized into three groups (non-detection < 0.02 μg L^-1 vs. medium BPS; 0.02–0.05 μg L^-1 vs. high BPS ≥ 0.05 μg L^-1), the high BPS group showed higher serum uric acid concentrations (by 0.26 mg dL^-1, P = 0.003) than the non-detection group after adjusting for covariates, which was significant in boys but not girls.

Discussions

Urinary BPS levels was positively associated with serum uric acid concentrations in 6-year-old children, and the association was more pronounced in boys. Considering the increasing use of BPS and concerning effect of hyperuricemia on health outcomes, their positive relationship should be investigated further.

Association between uric acid and height during growth hormone therapy in children with idiopathic short stature

BACKGROUND

Serum uric acid (UA) within appropriate levels is reported to be beneficial in patients with idiopathic short stature (ISS). This study aimed to evaluate the association between serum UA levels and height standard deviation scores (SDS) in patients with ISS during growth hormone (GH) therapy.

METHODS

A longitudinal study (LG Growth Study) of 182 children (mean age: 7.29±2.60 years) with ISS was performed. All participants were in the prepubertal stage and treated with GH, and the data within a treatment period of 30 months were analyzed.

RESULTS

In the adjusted Pearson's correlation, UA was significantly correlated with height SDS after controlling for sex, age, and body mass index (BMI) SDS (r=0.22, p=0.007). In the adjusted multiple regression analyses, the height SDS was significantly associated with UA after controlling for sex, age, and BMI SDS (β=0.168, p=0.007). Within the 30-month treatment period, the UA levels significantly increased as the height SDS increased, and the mean UA levels at baseline and 30 months after treatment were 3.90±0.64 mg/dL and 4.71±0.77 mg/dL, respectively (p=0.007).

DISCUSSION

In conclusion, UA is related to height SDS, and GH treatment leads to a significant increase in UA without hyperuricemia. Elevated UA is considered a favorable outcome of GH therapy, and further studies are needed to determine its role as a monitoring tool.

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.

Can biomarkers be used to improve diagnosis and prediction of metabolic syndrome in childhood cancer survivors? A systematic review

Childhood cancer survivors (CCS) are at increased risk to develop metabolic syndrome (MetS), diabetes, and cardiovascular disease. Common criteria underestimate adiposity and possibly underdiagnose MetS, particularly after abdominal radiotherapy. A systematic literature review and meta-analysis on the diagnostic and predictive value of nine newer MetS related biomarkers (adiponectin, leptin, uric acid, hsCRP, TNF-alpha, IL-1, IL-6, apolipoprotein B (apoB), and lipoprotein(a) [lp(a)]) in survivors and adult non-cancer survivors was performed by searching PubMed and Embase. Evidence was summarized with GRADE after risk of bias evaluation (QUADAS-2/QUIPS). Eligible studies on promising biomarkers were pooled. We identified 175 general population and five CCS studies. In the general population, valuable predictive biomarkers are uric acid, adiponectin, hsCRP and apoB (high level of evidence), and leptin (moderate level of evidence). Valuable diagnostic biomarkers are hsCRP, adiponectin, uric acid, and leptin (low, low, moderate, and high level of evidence, respectively). Meta-analysis showed OR for hyperuricemia of 2.94 (age-/sex-adjusted), OR per unit uric acid increase of 1.086 (unadjusted), and AUC for hsCRP of 0.71 (unadjusted). Uric acid, adiponectin, hsCRP, leptin, and apoB can be alternative biomarkers in the screening setting for MetS in survivors, to enhance early identification of those at high risk of subsequent complications.

Overview of pediatric obesity: diagnosis, epidemiology, and significance

Background: The prevalence of pediatric obesity has increased over the past several decades worldwide and in Korea. Childhood obesity has become a serious social problem.Current Concepts: Diagnosis of obesity is based on body mass index (BMI) in children and adolescents aged ≥2 years. Overweight and obese are defined as BMI ≥85th percentile to <95th percentile and BMI ≥95th percentile, respectively, corresponding to sex and age. Obesity is further classified as Class I (BMI ≥95th percentile to <120% of 95th percentile), Class II (BMI ≥120% of 95th percentile to <140% of 95th percentile), and Class III (BMI ≥140% of 95th percentile). Waist circumference and waist-height ratio are used to evaluate abdominal obesity. Pediatric obesity can cause childhood comorbidities, including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and hypertension. Adult obesity, cardiovascular diseases, and other adult comorbidities, together with increased medical costs are additional consequences of pediatric obesity.Discussion and Conclusion: Prevention, diagnosis, and proper management of pediatric obesity are important.