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

Association Between Hyperuricemia, Body Composition, and Comorbidities in an Obese Pediatric Population

Background: Childhood obesity is a global issue with multifactorial causes, leading to chronic and complex disease affecting all organs and systems with high morbidity and mortality, later in life. Elevated serum uric acid (SUA) levels are linked to several comorbidities in adults. In children, however, SUA levels vary by age, sex, and pubertal stage, and therefore, this relation is not well documented. While higher body mass index (BMI) has been associated with SUA levels, other nutritional assessment methods have not been thoroughly investigated and the link between SUA levels and obesity comorbidities in children is underexplored. Objective: This study aims to determine if hyperuricemia is related to body composition and obesity-related comorbidities in children. Methods: A retrospective analysis examined records from 505 obese children aged 5 to 18. The study evaluated the relationship between three nutritional assessment methods: BMI, waist-to-height ratio (WHtR), and body fat mass (BFM) percentage determined by bioimpedance (using InBody 270 scale), SUA levels, and blood markers associated with target organ damage. Results: A significant correlation was found between all three nutritional assessment methods (p < 0.001). WHtR showed a stronger correlation with the assessed comorbidities than the BMI z-score. SUA level correlated with HOMA-IR, ALT level, and lipid profile (p < 0.001). Multiple linear regression indicated an association between SUA level, BFM percentage, and WHtR (p < 0.001). Significant differences in body composition, SUA, and comorbidity markers were observed between children with and without hepatic steatosis (p < 0.05). Conclusion: Our results indicated a strong correlation among all nutritional assessment methods; however, WHtR and BFM percentage had a better correlation with obesity complications. SUA is a potential marker for insulin resistance, inflammation, and metabolic dysfunction-associated fatty liver disease (MAFLD) in obese children.

Prevalence of and trends in hyperuricemia by race and ethnicity among US adolescents, 1999-2018

PURPOSE

Our objective was to ascertain the most recent prevalence and trends of hyperuricemia among adolescents, stratified by sex and race/ethnicity subgroups, as well as to investigate potential risk factors associated with hyperuricemia in US adolescents.

METHODS

Data were obtained from adolescents aged 12-17 years in the 1999-2018 NHANES cycles. Hyperuricemia for adolescents was defined as ≥ 5.5 mg/dL. The prevalence of hyperuricemia, along with 95% confidence intervals (CIs), was calculated for each four-year survey cycle, stratified by sex, race/ethnicity, body mass index (BMI), poverty income ratio (PIR), and parental education levels. Linear regression and logistic regression analyses were conducted independently to evaluate the linear trends in mean serum urate levels and the prevalence of hyperuricemia across the four-year cycles. Utilizing NHANES data from 2011 to 2018, we identified factors associated with mean serum urate levels and hyperuricemia through the application of linear regression and Poisson regression analyses.

RESULTS

A total of 11 264 participants were included in the analysis. In 2015-2018, the overall hyperuricemia prevalence was 32.78%, 50.7% in males, and 13.51% in females. No significant trends were identified in the prevalence of hyperuricemia from 1999 to 2002 to 2015-2018. Between 2011 and 2018, hyperuricemia was significantly more prevalent among males compared to females (prevalence ratio [PR], 3.50 [95% CI, 2.83-4.33]), non-Hispanic Asians compared to non-Hispanic Whites (PR, 1.26 [95% CI, 1.04-1.53]), and individuals with overweight (PR, 1.63 [95% CI, 1.32-2.01]) or obesity (PR, 2.45 [95% CI, 2.08-2.88]) compared to those of normal weight. There was a stronger correlation between obesity and hyperuricemia among females (PR, 4.77 [95% CI, 3.08-7.39]) than in males (PR, 2.06 [95% CI, 1.82-2.34]). Furthermore, non-Hispanic Black adolescents with obesity exhibited higher PRs (PR, 3.40 [95% CI, 2.54-4.55]) for hyperuricemia in comparison to other ethnic groups.

CONCLUSIONS

This study has updated recent trends in hyperuricemia by sex and race/ethnicity among US adolescents. Our results suggest that hyperuricemia has a significant association with greater obesity in US adolescents, and the degree of correlation varies by sex and race/ethnicity.

Effects of irisin and exercise on adropin and betatrophin in a new metabolic syndrome model

Metabolic syndrome (MetS) is a prevalent public health problem. Uric acid (UA) is increased by MetS. We investigated whether administration of UA and 10% fructose (F) would accelerate MetS formation and we also determined the effects of irisin and exercise. We used seven groups of rats. Group 1 (control); group 2 (sham); group 3 (10% F); group 4 (1% UA); group 5 (2% UA); group 6 (10% F + 1% UA); and Group 7, (10% F + 2% UA). After induction of MetS (groups 3 -7), Group 3 was divided into three subgroups: 3A, no further treatment; 3B, irisin treatment; 3C, irisin treatment + exercise. Group 4, 1% UA, which was divided into three subgroups: 4A, no further treatment; 4B, irisin treatment; 4C, Irisin treatment + exercise. Group 5, 2% UA, which was divided into three subgroups: 5A, no further treatment; 5B, irisin treatment; 5C, irisin treatment + exercise. Group 6, 10% F + 1% UA, which was divided into three subgroups: 6A, no further treatment; 6B, irisin treatment; 6C, irisin treatment + exercise. Group 7, 10% F + 2% UA, which was divided into three subgroups: 7A, no further treatment; 7B, irisin treatment; 7C, irisin treatment + exercise., İrisin was administered 10 ng/kg irisin intraperitoneally on Monday, Wednesday, Friday, Sunday each week for 1 month. The exercise animals (in addition to irisin treatment) also were run on a treadmill for 45 min on Monday, Wednesday, Friday, Sunday each week for 1 month. The rats were sacrificed and samples of liver, heart, kidney, pancreas, skeletal muscles and blood were obtained. The amounts of adropin (ADR) and betatrophin in the tissue supernatant and blood were measured using an ELISA method. Immunohistochemistry was used to detect ADR and betatrophin expression in situ in tissue samples. The duration of these experiments varied from 3 and 10 weeks. The order of development of MetS was: group 7, 3 weeks; group 6, 4 weeks; group 5, 6 weeks; group 4, 7 weeks; group 3, 10 weeks. Kidney, liver, heart, pancreas and skeletal muscle tissues are sources of adropin and betatrophin. In these tissues and in the circulation, adropin was decreased significantly, while betatrophin was increased significantly due to MetS; irisin + exercise reversed this situation. We found that the best method for creating a MetS model was F + UA2 supplementation. Our method is rapid and simple. Irisin + exercise was best for preventing MetS.

Asymptomatic hyperuricemia: to treat or not a threat? A clinical and evidence-based approach to the management of hyperuricemia in the context of cardiovascular diseases

Asymptomatic hyperuricemia is defined by serum uric acid levels above 6.2 mg/dl in women and 7 mg/dl in men. In the presence of monosodium urate crystal formation and articular inflammation, hyperuricemia may become symptomatic (namely nephrolithiasis and gout). Uric acid results from purine catabolism and is at the centre of a complex metabolic interplay that involves oxidative stress, inflammation, renin-angiotensin-aldosterone system (RAAS) activation and insulin resistance. Uric acid levels present a continuous relation with conditions like hypertension and chronic kidney disease (CKD) and are reported to have an impact on risk of cardiovascular events. However, whether elevated uric acid is a causal agent and thus a possible therapeutic target is still uncertain and matter of further investigation. Treating symptomatic hyperuricemia involves lowering uric acid drugs and controlling inflammation. Urate-lowering agents are well tolerated but show minimal impact on cardiovascular events in patients with gout. Use of direct-acting urate-lowering agents in asymptomatic hyperuricemia associated with cardiovascular diseases does not warrant a clear benefit, whereas addressing cardiovascular issues with guideline-recommended therapies lowers uric acid and reduces the occurrence of cardiovascular events. Regular assessment of uric acid and clinical symptoms is advised before starting and renewing a urate-lowering treatment.

Uric Acid Levels in Overweight and Obese Children, and Their Correlation With Metabolic Risk Factors

BACKGROUND

Obesity is an ongoing medical condition that continues to rise on a global scale. Numerous metabolic disorders, such as type 2 diabetes mellitus, hyperlipidemia, and hyperuricemia, are closely associated with obesity. This particular study aims to investigate the occurrence of hyperuricemia and its association with other metabolic factors among children and adolescents aged 6 to 14 years who are overweight or obese residing in Riyadh, Saudi Arabia.

METHODS

In this research, a cross-sectional, descriptive, and analytical study was carried out on 339 children and adolescents. These participants were selected randomly from a list of patients who had sought medical care for overweight and obesity at the pediatric endocrinology, general pediatrics, and family medicine clinics in King Abdulaziz Medical City (KAMC), located in Riyadh, Saudi Arabia, in the period from January 2020 to January 2022. To gather the necessary data, the electronic medical records of the participating individuals were carefully reviewed, encompassing various relevant variables, including demographic characteristics, anthropometric measurements, serum uric acid levels, lipid profiles, and fasting blood sugar.

RESULTS

Out of the total 339 participants, 48 (14.2%) were identified as overweight, while 291 (85.8%) were classified as obese. The study revealed that the overall prevalence of hyperuricemia among the participants was 54%. There was an increased risk of hyperuricemia associated with male gender and elevated levels of LDL and TG.

CONCLUSION

The significant prevalence of hyperuricemia among children and adolescents who are overweight or obese is evident. In order to improve control and management of this condition, it is crucial to prioritize the promotion of a healthy lifestyle among these individuals.

2024 Guidelines of the Taiwan Society of Cardiology on the Primary Prevention of Atherosclerotic Cardiovascular Disease --- Part I

Atherosclerotic cardiovascular disease (ASCVD) is one of the leading causes of death worldwide and in Taiwan. It is highly prevalent and has a tremendous impact on global health. Therefore, the Taiwan Society of Cardiology developed these best-evidence preventive guidelines for decision-making in clinical practice involving aspects of primordial prevention including national policies, promotion of health education, primary prevention of clinical risk factors, and management and control of clinical risk factors. These guidelines cover the full spectrum of ASCVD, including chronic coronary syndrome, acute coronary syndrome, cerebrovascular disease, peripheral artery disease, and aortic aneurysm. In order to enhance medical education and health promotion not only for physicians but also for the general public, we propose a slogan (2H2L) for the primary prevention of ASCVD on the basis of the essential role of healthy dietary pattern and lifestyles: "Healthy Diet and Healthy Lifestyles to Help Your Life and Save Your Lives". We also propose an acronym of the modifiable risk factors/enhancers and relevant strategies to facilitate memory: " ABC2D2EFG-I'M2 ACE": Adiposity, Blood pressure, Cholesterol and Cigarette smoking, Diabetes mellitus and Dietary pattern, Exercise, Frailty, Gout/hyperuricemia, Inflammation/infection, Metabolic syndrome and Metabolic dysfunction-associated fatty liver disease, Atmosphere (environment), Chronic kidney disease, and Easy life (sleep well and no stress). Some imaging studies can be risk enhancers. Some risk factors/clinical conditions are deemed to be preventable, and healthy dietary pattern, physical activity, and body weight control remain the cornerstone of the preventive strategy.

Dietary fructose: from uric acid to a metabolic switch in pediatric metabolic dysfunction-associated steatotic liver disease

Fructose consumption in pediatric subjects is rising, as the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). Despite increasing evidence supporting the detrimental effects of fructose in the development of Metabolic Syndrome (MetS) and its related comorbidities, the association between fructose intake and liver disease remains unclear, mainly in youths. The current narrative review aims to illustrate the correlation between fructose metabolism and liver functions besides its impact on obesity and MASLD in pediatrics. Fructose metabolism is involved in the liver through the classical lipogenic pathway via de novo lipogenesis (DNL) or in the alternative pathway via uric acid accumulation. Hyperuricemia is one of the main features of MALSD patients, underlining how uric acid is growing interest as a new marker of disease. Observational and interventional studies conducted in children and adolescents, who consumed large amounts of fructose and glucose in their diet, were included. Most of these studies emphasized the association between high fructose intake and weight gain, dyslipidemia, insulin resistance, and MASLD/MASH, even in normal-weight children. Conversely, reducing fructose intake ameliorates liver fat accumulation, lipid profile, and weight. In conclusion, fructose seems a potent inducer of both insulin resistance and hepatic fat accumulation.

Association of serum uric acid with hypertriglyceridemia in children and adolescents: a cross-sectional study

BACKGROUND

Uric acid (UA), a liver-derived metabolite, is intimately tied to metabolic disorders. Although ample research underscores its connection with hypertriglyceridemia (HTG), studies focusing on adolescents remain limited. To fill the gaps in epidemiology,this study focused on analyzing the relationship between the levels of uric acid and HTG in a demographic sample comprising adolescents from the United States.

METHODS

In this study, a total of 4,435 participants through the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020. The exposure variable was serum uric acid (SUA), the effect variable was HTG, and the covariates included demographic, questionnaire, physical examination and laboratory indicators. We utilized weighted logistic regression and meticulous subgroup evaluations to discern the intrinsic link between SUA and HTG. Stratified analyses augmented the validation of this association, while smooth curve fitting probed for potential nonlinear correlations.

RESULTS

The study included 4,435 participants. Male adolescents exhibit elevated SUA levels. After adjusting for all variables, the weighted multiple logistic regression model revealed that SUA was positively correlated with HTG risk (OR = 1.006, 95% CI: 1.005-1.007). This relationship was consistent across the three tertiles group of SUA (T1: OR = 1.006 [95% CI: 1.005-1.007]; T2: OR = 1.006 [95% CI: 1.005-1.007]; T3: OR = 1.004 [95% CI: 1.003-1.006]; P for trend < 0.001). Stratified analyses confirmed that the positive correlation between SUA and HTG risk was significant, irrespective of sex, age or race.

CONCLUSIONS

In American children and adolescents aged 12 to 18 years, there was a pronounced association between SUA and HTG. SUA could serve as a risk indicator for HTG. It is recommended that children diagnosed with HTG should be regularly tested for SUA levels. In addition, it is recommended that SUA be included in the comprehensive care of children diagnosed with HTG.

Associations of serum uric acid with hypertension status, stages, phenotypes and progressions among Chinese middle-aged and elderly

BACKGROUND AND AIMS

No consensus has been reached on the association between serum uric acid (SUA) and hypertension. This study aimed to investigate the associations between SUA and hypertension, including its status, stages, phenotypes and progressions, among middle-aged and older Chinese.

METHODS AND RESULTS

Data were obtained from the China Health and Retirement Longitudinal Study 2011-2015. Binary logistic regression was used to evaluate the association between SUA and hypertension status. Multinomial logistic regression was used to explore the associations of SUA with hypertension stages, phenotypes and hypertension status progressions. Models were adjusted for potential confounders and stratified by sex. A total of 7931 individuals aged ≥45 years were included, with 39.16 % of hypertension. Significant associations were found of SUA with stage2 and above hypertension (quartile 4 [Q4] vs quartile 1 [Q1]: odds ratio 1.78, 95 % confidence interval 1.31-2.42, P < 0.001), and systolic diastolic hypertension (SDH) (Q4 vs Q1: 1.53, 1.14-2.06, P = 0.005). In sex stratification, significant associations were found between SUA and stage2 and above hypertension and SDH only for men. Moreover, higher quartiles of baseline SUA showed increased risks of maintained hypertension from 2011 to 2015 (Q3 vs Q1: 1.23, 1.03-1.48, P = 0.024; Q4 vs Q1: 1.73, 1.43-2.10, P < 0.001).

CONCLUSION

Higher SUA was associated with hypertension and maintained hypertension among Chinese middle-aged and elderly. Sex-specific associations of SUA with hypertension stages and phenotypes were observed. Regular measurement of SUA in clinical practice may indicate hypertension and its progression, particularly among men.

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 could be a marker of cardiometabolic risk and disease severity in children with juvenile idiopathic arthritis

In addition to disease-specific complications, juvenile idiopathic arthritis (JIA) has been linked to metabolic impairments in adults. Recent data supported the usefulness of uric acid (UA) as risk factor for cardiometabolic derangements. Given the lack of pediatric evidence in this field, we aimed to explore this association in a cohort of children diagnosed with JIA. We retrospectively evaluated 113 children diagnosed with JIA classified according to the International League of Association for Rheumatology (ILAR) criteria attending our Rheumatology Clinic. Both clinical and biochemical assessments were performed. Participants were stratified in four groups according to quartiles of serum UA. Disease activity was calculated by the Juvenile Arthritis Disease Activity Score 10 (JADAS-10) joint reduced count, and cut-offs for disease states were applied. Patients belonging to the highest UA quartile showed higher serum triglycerides, total cholesterol, creatinine, and glucose levels (p = 0.01, p = 0.025, p = 0.04, and p = 0.005, respectively) and lower HDL cholesterol values (p < 0.0001) than subjects belonging to the lowest quartiles. Ferritin, erythrocyte sedimentation rate levels, and age at disease onset did not significantly differ across UA quartiles (all p > 0.05). As activity disease index, JADAS-10 score significantly increased across UA quartiles (p = 0.009).

CONCLUSION

Children with JIA presented with a worse cardiometabolic profile and a greater disease severity across UA quartiles. Our findings suggest that in clinical practice, UA might represent a useful marker of cardiometabolic risk and disease severity in children with JIA.

WHAT IS KNOWN

• JIA has been linked to metabolic derangements in adulthood. • UA has been recognized as a marker of cardiometabolic risk both in adults and children.

WHAT IS NEW

• Children with JIA belonging to the highest UA quartile showed a worse cardiometabolic profile and a greater disease severity. • UA might represent a helpful marker not only of cardiometabolic risk but also of disease severity in children with JIA.

Apigenin Ameliorates Hyperuricemia and Renal Injury through Regulation of Uric Acid Metabolism and JAK2/STAT3 Signaling Pathway

Hyperuricemia (HUA) is a kind of metabolic disease with high incidence that still needs new countermeasures. Apigenin has uric-lowering and kidney-protective activities, but how apigenin attenuates HUA and renal injury remains largely unexploited. To this end, an acute HUA mouse model was established by intraperitoneal injection of potassium oxazinate and oral administration with hypoxanthine for 7 consecutive days. Apigenin intervention decreased serum uric acid (UA), creatinine (CRE), blood urea nitrogen (BUN), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), interleukin-18 (IL-18), liver xanthine oxidase (XOD), and urine protein levels, and increased serum interleukin-10 (IL-10) and urine UA and CRE levels in HUA mice. Moreover, administration of apigenin to HUA mice prevented renal injury, decreased renal glucose transporter 9 (GLUT9) and urate anion transporter 1 (URAT1) levels, and increased renal organic anion transporter 1 (OAT1). These alterations were associated with an inhibition of IL-6, phospho-janus kinase 2 (P-JAK2), phospho-signal transducer, and activator of transcription 3 (P-STAT3), and suppression of cytokine signaling 3 (SOCS3) expression in the kidneys. Additionally, the molecular docking results showed that apigenin had strong binding capacity with UA transporters and JAK2 proteins. In summary, apigenin could improve UA metabolism and attenuate renal injury through inhibiting UA production, promoting excretion, and suppressing the JAK2/STAT3 signaling pathway in HUA mice. The results suggest that apigenin may be a suitable drug candidate for management of HUA and its associated renal injury.

Uric Acid and Hypertension: a Review of Evidence and Future Perspectives for the Management of Cardiovascular Risk

Uric acid is the final product of purine metabolism, and its increased serum levels have been directly involved in the pathogenesis and natural history of hypertension. The relationship between elevated uric acid and hypertension has been proven in both animals and humans, and its relevance is already evident in childhood and adolescent population. The mechanism responsible for blood pressure increase in hyperuricemic subjects is implicating both oxidative stress and intracellular urate activity with a primary involvement of XOR (xanthine-oxidoreductase activity). An increase in the relative risk of hypertension has been confirmed by genetic data and by large meta-analyses of epidemiological data. The effects of urate-lowering treatment on blood pressure control in patients with elevated serum uric acid has been investigated in a small number of reliable studies with a large heterogeneity of patient populations and study designs. However, 2 large meta-analyses suggest a significant effect of urate-lowering treatment on blood pressure, thus confirming the significant relationship between high serum urate and blood pressure. The future research should be focused on a more appropriate identification of patients with cardiovascular hyperuricemia by considering the correct cardiovascular threshold of serum urate, the time-course of uricemia fluctuations, and the identification of reliable markers of urate overproduction that could significantly clarify the clinical and therapeutic implications of the interaction between serum uric acid and hypertension.

Prevalence of hyperuricemia in patients with severe obesity and the relationship between serum uric acid and severe obesity: A decade retrospective cross-section study in Chinese adults

OBJECTIVE

Undoubtedly, the relationship between serum uric acid (SUA) and obesity is less data for Chinese patients with obesity. This study aimed to examine the prevalence of hyperuricemia (HUA) and the association between SUA and patients with obesity.

METHODS

All participants were categorized as overweight, obesity I, obesity II, and obesity III. In addition, based on SUA concentration, the participants were stratified into four quartiles. The authors used descriptive analysis, independent t-test, ANOVA, correlation analysis, and multiple linear regression models to verify the SUA level and obesity among Chinese adults.

RESULTS

Overall, the estimated prevalence of HUA was 69.8%. In the BMI categories, the prevalence of HUA was 5.1% in overweight, 15.2% in obesity I, 16.9% in obesity II, and 32.5% in obesity III. Correlation analysis shows that SUA is strongly correlated with BMI, waist circumference (WC), and hip circumference (HC). Multiple linear regression analysis shows that high density-lipoprotein cholesterol (HDL-C) is a protective predictor of serum uric acid levels in patients with obesity. Compared with the overweight, obesity I, obesity II, and obesity III were more likely to have higher levels in the SUA levels.

CONCLUSION

We mainly showed that the serum uric acid levels in Chinese patients with severe obesity declined slightly as age increased.

Altered Gut Microbiota in Children With Hyperuricemia

Background

In adults, gut dysbiosis may contribute to the pathogenesis of gout. However, the characteristics of gut microbiota in children with hyperuricemia (HUA) in the absence of clinical gout have not been explored.

Objective

This present study analyzed the gut microbiota in children with HUA as compared to controls (Con) and explored bacterial associations that may account for differences.

Methods

A total of 80 children were enrolled in this study; they were divided into HUA and Con according to the level of serum uric acid (UA). The composition of gut microbiota was investigated by 16S rRNA high-throughput sequencing.

Results

Principal coordinate analysis revealed that gut microbiota of the HUA group was clustered together and separated partly from the Con group. There was no difference in alpha-diversity between the two groups. However, Spearman's correlation analysis revealed that serum UA level positively correlated with genera Actinomyces, Morganella, and Streptococcus, and negatively associated with the producers of short-chain fatty acids (SCFAs), such as Alistipes, Faecalibacterium, and Oscillospira, and the sulfidogenic bacteria Bilophila. The members of the genera Alistipes and Bilophila in the Con group were significantly more prevalent than the HUA subjects. Compared to the Con cohort, metabolic pathway predictions found that the superpathways of purine nucleotide de novo biosynthesis were decreased in HUA subjects, whereas the superpathway of purine deoxyribonucleoside de gradation was increased.

Conclusion

The composition of the gut microbiota in children with HUA differs from Con. Although causality cannot be established, modification in the microbiota that produces SCFA and sulfide may promote HUA.

The adolescent with obesity: what perspectives for treatment?

The dramatic increase in overweight and obesity among children and adolescents has become a major public health problem. Obesity in children and young adults is associated with an increased prevalence of cardiometabolic risk factors. Obesity during adolescence represents a strong predictor of obesity and higher mortality in adulthood. Due to the serious implications of obesity in adolescents, effective treatments are urgently needed. Lifestyle interventions represent the recommended therapy. Nevertheless, real world data show that the majority of adolescents do not achieve weight loss in the long term, and are reluctant to participate in lifestyle interventions. Pharmacological treatment is recommended if a formal lifestyle modification program fails to limit weight gain or to improve comorbidities. However, until 2020 the European Medicines Agency (EMA) had not approved any pharmacotherapeutic agents for obesity in pediatric patients. On April 2021, EMA has authorized the use of Liraglutide, a glucagon-like peptide (GLP)-1 analog, for the treatment of obesity in adolescents (12–17 years). The efficacy and safety of Liraglutide were demonstrated in a randomized, double-blind trial, enrolling 251 adolescents. After 56 weeks, a reduction in BMI of at least 5% was observed in 43.3% of participants in the liraglutide group vs. 18.7% in the placebo group, and a reduction in BMI of at least 10% was observed in 26.1 and 8.1%, respectively. Gastrointestinal events were the events most frequently reported with liraglutide. Bariatric surgery represents another effective treatment for adolescents with severe obesity, with sustained benefits on weight loss and cardiometabolic risk factors. However, long-term safety and effectiveness data in adolescents are still scarce. Risks of bariatric surgery include the need for additional abdominal surgical procedures and specific micronutrient deficiencies. Hopefully, new pharmacological treatments in addition to lifestyle interventions will offer more chances of success.

Upregulated Guanine Deaminase Is Involved in Hyperpigmentation of Seborrheic Keratosis via Uric Acid Release

Seborrheic keratosis, which is a benign tumor composed of epidermal keratinocytes, develops common in the elderly. Uric acid generated by upregulated guanine deaminase (GDA) has been identified to cause UV-induced keratinocyte senescence in seborrheic keratosis. Seborrheic keratosis is also frequently pigmented. Growing evidences indicate that hyperuricemia is a risk factor of acanthosis nigricans, an acquired skin hyperpigmentation. The objective of this study was to investigate role of GDA and its metabolic end product, uric acid, in hyperpigmentation of patients with seborrheic keratosis using their lesional and non-lesional skin specimen sets and cultured primary human epidermal keratinocytes with or without GDA overexpression or uric acid treatment. GDA-overexpressing keratinocytes or their conditioned media containing uric acid increased expression levels of MITF and tyrosinase in melanocytes. Uric acid released from keratinocytes was facilitated by ABCG2 transporter with the help of PDZK1 interaction. Released uric acid was taken by URAT1 transporter in melanocytes, stimulating melanogenesis through p38 MAPK activation. Overall, GDA upregulation in seborrheic keratosis plays a role in melanogenesis via its metabolic end product uric acid, suggesting that seborrheic keratosis as an example of hyperpigmentation associated with photoaging.

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.

Molecular Biological and Clinical Understanding of the Pathophysiology and Treatments of Hyperuricemia and Its Association with Metabolic Syndrome, Cardiovascular Diseases and Chronic Kidney Disease

Uric acid (UA) is synthesized mainly in the liver, intestines, and vascular endothelium as the end product of an exogenous purine from food and endogenously from damaged, dying, and dead cells. The kidney plays a dominant role in UA excretion, and the kidney excretes approximately 70% of daily produced UA; the remaining 30% of UA is excreted from the intestine. When UA production exceeds UA excretion, hyperuricemia occurs. Hyperuricemia is significantly associated with the development and severity of the metabolic syndrome. The increased urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) expression, and glycolytic disturbances due to insulin resistance may be associated with the development of hyperuricemia in metabolic syndrome. Hyperuricemia was previously thought to be simply the cause of gout and gouty arthritis. Further, the hyperuricemia observed in patients with renal diseases was considered to be caused by UA underexcretion due to renal failure, and was not considered as an aggressive treatment target. The evidences obtained by basic science suggests a pathogenic role of hyperuricemia in the development of chronic kidney disease (CKD) and cardiovascular diseases (CVD), by inducing inflammation, endothelial dysfunction, proliferation of vascular smooth muscle cells, and activation of the renin-angiotensin system. Further, clinical evidences suggest that hyperuricemia is associated with the development of CVD and CKD. Further, accumulated data suggested that the UA-lowering treatments slower the progression of such diseases.

Uric Acid Associates With Executive Function in Children and Adolescents With Hypertension

[Figure: see text].

Oxidant/antioxidant status in Type-2 diabetes mellitus patients with metabolic syndrome

BACKGROUND

The concurrence of metabolic syndrome (MS) and diabetes mellitus (DM) is increasing worldwide. The long-term complications of these chronic diseases are a threat to patients' well-being. Oxidative stress is involved in the pathogenesis of several diseases. To understand the basic pathophysiological mechanisms of Type-2 DM (T2DM) and its related complications, we aimed to investigate the oxidant/antioxidant status and Na+-K+ ATPase activity in T2DM with MS.

MATERIALS AND METHODS

A population of ninety individuals including fifty patients diagnosed with T2DM and MS, but without overt diabetes complications, and forty individuals without T2DM or MS as control group participated in this study. Plasma malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, total antioxidant capacity (TAC), and Na+-K+ ATPase activity were assessed by standard laboratory methods.

RESULTS

Plasma MDA in patients group was statistically significantly higher than that of controls (P ≤ 0.05). Whereas, Na+-K+ ATPase activity was statistically significantly lower in patient group (P ≤ 0.05). TAC, CAT, SOD, and GPx enzyme activities were not statistically significantly different between two groups (P > 0.05). Results from the patient group showed positive correlations between CAT activity and triglyceride and positive correlations between GPx activity and weight, body mass index (BMI), and waist circumference. In addition, there was a positive correlation between MDA results with high-density lipoprotein-cholesterol (HDL-C) and total cholesterol and a negative correlation with TAC, BMI, and weight (P ≤ 0.05) in controls.

CONCLUSION

Because T2DM patients were without any vascular complications, antioxidant defense results may reflect the lack of progression of diabetes complications in these patients. These results emphasize the need for initial and continued assessment of cardiovascular disease risks in diabetic individuals. Implementation of timely interventions may improve the management of diabetes and prevent the progression of diabetes complications.

Incidence of metabolic syndrome and determinants of its progression in Southern Iran: A 5-year longitudinal follow-up study

BACKGROUND

Metabolic syndrome (MetS) is a cluster of conditions increasing the risk of serious diseases. This study aimed to define the predictors of MetS incident in a community-based cohort in Southern Iran, during a mean follow-up period of 5.1 years.

MATERIALS AND METHODS

During the mean follow-up period of 5.1 years, a cohort study was conducted on 819 Iranian adults aged ≥18 years at baseline and followed to determine the incidence and predictors of MetS progression in Shiraz, a main urban region in the southern part of Iran. The International Diabetes Federation Guideline was used to detect the MetS. Multiple Cox's proportional hazards models were also used to estimate the predictors of new-onset MetS.

RESULTS

The prevalence of MetS was 25.9% at baseline, and the overall incidence of subsequent MetS was 5.45% (95% confidence interval [CI]: 4.47-6.59). The incidence of MetS was significantly higher in women (7.12% [95% CI: 5.52-9.05]) than in men (3.92% [95% CI: 2.80-5.34]). Moreover, it increased by 5.02 (95% CI, 3.75-6.58) among individuals who had one metabolic component and by 12.65 (95% CI, 9.72-16.18) for those who had three or more components (P < 0001). The incidence of MetS was also analyzed using the multiple Cox's proportional hazards model for potential risk factors, and it was revealed that female gender (hazard ratio [HR] 2.45; 95% CI: 1.33, 4.50; P = 0.004), higher body mass index (HR 3.13; 95% CI: 1.43.6.84; P = 0.012), increased abdominal obesity (HR 1.45; 95% CI 0.85, 2.46; P = 0.045), smoking (HR 4.79; 95% CI 2.09, 10.97; P < 0.001), and lower high-density lipoprotein (HR 0.53; 95% CI: 0.29, 1.00; P = 0.044) significantly predicted the onset of MetS at baseline; however, age, systolic and diastolic blood pressure, serum uric acid, fasting blood glucose, cholesterol, triglyceride and creatinine, estimated glomerular filtration rate, marital status, level of education, and level of physical activity did not independently predict the onset of MetS when other covariates were considered.

CONCLUSION

This study showed the high-incidence rates of MetS in males and females residing in Southern Iran. Therefore, the prevention through community-based lifestyle modification should be implemented to reduce the burden of MetS and its complications.