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

Managing Gout in Patients with Metabolic Syndrome

Gout is characterized by monosodium urate (MSU) crystal deposition secondary to hyperuricemia. Gout is associated with metabolic syndrome (MetS) and its related comorbid conditions such as cardiovascular disease (CVD). Major advances have been made in the comprehension of the link between MetS and gout. Despite observational studies suggesting an association between MetS-related conditions and hyperuricemia, there is no proof of causality. Most studies using Mendelian randomization did not find hyperuricemia as a causal factor for MetS-related conditions. In contrast, these conditions were found associated with hyperuricemia, which suggests a reverse causality. Among patients with gout, this high CVD risk profile implies the need for systematic screening for MetS-related conditions. Most international guidelines recommend systematic screening for and care of CVD and related risk factors in patients with gout. Some anti-hypertensive agents, such as losartan and calcium channel blockers, are able to decrease serum urate (SU) levels. However, there are potential interactions between gout management therapies and the treatment of metabolic diseases. Some data suggest that anti-inflammatory drugs used for gout flare treatment, such as colchicine or canakinumab, might have benefits for CVD. Regarding the impact of urate-lowering therapies on CVD risk, recent studies found a similar CVD safety profile for allopurinol and febuxostat. Finally, sodium-glucose cotransporter-2 inhibitors are promising for gout because of their ability to decrease SU levels and risk of recurrent flares. In this review, we focus on the clinical challenge of managing MetS in patients with gout, particularly older patients with co-medications.

Gut microbiota profiling in obese children from Southeastern China

Childhood obesity not only has a negative impact on a child's health but is also a significant risk factor for adult obesity and related metabolic disorders, making it a major global public health concern. Recent studies have revealed the crucial role of gut microbiota in the occurrence and development of obesity, in addition to genetic and lifestyle factors. In this study, we recruited 19 normal-weight children and 47 children with varying degrees of obesity. A questionnaire survey was conducted to inquire about the family background, lifestyle habits and dietary composition of the 66 children. Findings indicate that fathers of obese children tend to be obese themselves, while children with highly educated mothers are more likely to maintain a normal weight. Furthermore, overweight children tend to spend more time on electronic devices and less time on physical activities compared to their normal-weight counterparts. Obese children exhibit significant differences in breakfast and dinner dietary composition when compared to children with normal weight. Additionally, the gut microbiota of these 66 children was analyzed using 16S rRNA sequencing. Analysis of gut microbiota composition showed similar compositions among children with varying degrees of obesity, but significant differences were observed in comparison to normal-weight children. Obese children exhibited a reduced proportion of Bacteroidota and an increased proportion of Firmicutes, resulting in an elevated Firmicutes/Bacteroidota ratio. Moreover, Actinobacteriota were found to be increased in the gut microbiota of children with varying degrees of obesity. PICRUSt analysis indicated significant metabolic differences in the microbiota functions between obese and normal-weight children, suggesting the composition of gut microbiota could be a crucial factor contributing to obesity. These findings provide valuable insights for the treatment of childhood obesity.

Salivary uric acid across child development and associations with weight, height, and body mass index

Introduction

Obesity during childhood is a serious and growing chronic disease with consequences for lifelong health. In an effort to advance research into the preclinical indicators of pediatric obesity, we examined longitudinal assessments of uric acid concentrations in saliva among a cohort of healthy children from age 6-months to 12-years (n's per assessment range from 294 to 727).

Methods

Using data from a subsample of participants from the Family Life Project (an Environmental influences on Child Health Outcomes Program cohort), we: (1) characterized salivary uric acid (sUA) concentrations from infancy to early adolescence by sex and race; (2) assessed changes in sUA levels across development; and (3) evaluated associations between sUA concentrations and measures of child weight, height, and body mass index (BMI). Across four assessments conducted at 6-, 24-, 90-, and 154-months of age, 2,000 saliva samples were assayed for UA from 781 participants (217 participants had sUA data at all assessments).

Results

There were no significant differences in sUA concentrations by sex at any assessment, and differences in sUA concentrations between White and non-White children varied by age. At the 90- and 154-month assessments, sUA concentrations were positively correlated with measures of child weight, height, and BMI (90-month: weight- ρ(610) = 0.13, p < 0.01; height- ρ(607) = 0.10, p < 0.05; BMI- ρ(604) = 0.13, p < 0.01; 154-month: weight- ρ(723) = 0.18, p < 0.0001; height- ρ(721) = 0.10, p < 0.01; BMI- ρ(721) = 0.17, p < 0.0001). Group based trajectory modeling identified two groups of children in our sample with distinct patterns of sUA developmental change. The majority (72%) of participants showed no significant changes in sUA across time ("Stable" group), while 28% showed increases in sUA across childhood with steep increases from the 90- to 154-month assessments ("Increasing" group). Children in the Increasing group exhibited higher sUA concentrations at all assessments (6-month: t(215) = -5.71, p < 0.001; 24-month: t(215) = -2.89, p < 0.01; 90-month: t(215) = -3.89, p < 0.001; 154-month: t(215) = -19.28, p < 0.001) and higher weight at the 24- and 90-month assessments (24-month: t(214) = -2.37, p < 0.05; 90-month: t(214) = -2.73, p < 0.01).

Discussion

Our findings support the potential utility of sUA as a novel, minimally-invasive biomarker that may help advance understanding of the mechanisms underlying obesity as well as further surveillance and monitoring efforts for pediatric obesity on a large-scale.

A metabolome-wide association study of in utero metal and trace element exposures with cord blood metabolome profile: Findings from the Boston Birth Cohort

BACKGROUND

Exposure to metals lead (Pb), mercury (Hg), and cadmium (Cd) and trace elements selenium (Se) and manganese (Mn) has been linked to the developmental origins of cardiometabolic diseases, but the mechanisms are not well-understood.

OBJECTIVE

Conduct a metabolome-wide association study to understand how in utero exposure to Pb, Hg, Cd, Se, and Mn affects the metabolic programming of fetuses.

METHODS

We used data from the Boston Birth Cohort, which enrolled mother-child pairs from Boston, MA. We measured metals and trace elements in maternal red blood cells (RBCs) collected 24-72 h after delivery, and metabolites in cord blood collected at birth. We used multivariable linear regression to examine associations of metals and trace elements with metabolites and Bonferroni correction to account for multiple comparisons. We assessed non-linear associations of metals and trace elements with metabolites using restricted cubic spline plots.

RESULTS

This analysis included 670 mother-child pairs (57% non-Hispanic Black and 24% Hispanic). After Bonferroni correction, there were 25 cord metabolites associated with at least one of the metals or trace elements. Pb was negatively associated with the xenobiotic piperine, Cd was positively associated with xenobiotics cotinine and hydroxycotinine, and Hg was associated with 8 lipid metabolites (in both directions). Se and Mn shared associations with 6 metabolites (in both directions), which mostly included nucleotides and amino acids; Se was additionally associated with 7 metabolites (mostly amino acids, nucleotides, and carnitines) and Mn was additionally associated with C36:4 hydroxy phosphatidylcholine. Restricted cubic spline plots showed that most associations were linear.

DISCUSSION

Maternal RBC metal and trace element concentrations were associated in a dose-dependent fashion with cord blood metabolites. What remains to be determined is whether these metals- and trace elements-associated changes in cord metabolites can influence a child's risk of cardiometabolic diseases.

Prenatal metal mixtures and child blood pressure in the Rhea mother-child cohort in Greece

BACKGROUND

Child blood pressure (BP) is predictive of future cardiovascular risk. Prenatal exposure to metals has been associated with higher BP in childhood, but most studies have evaluated elements individually and measured BP at a single time point. We investigated impacts of prenatal metal mixture exposures on longitudinal changes in BP during childhood and elevated BP at 11 years of age.

METHODS

The current study included 176 mother-child pairs from the Rhea Study in Heraklion, Greece and focused on eight elements (antimony, arsenic, cadmium, cobalt, lead, magnesium, molybdenum, selenium) measured in maternal urine samples collected during pregnancy (median gestational age at collection: 12 weeks). BP was measured at approximately 4, 6, and 11 years of age. Covariate-adjusted Bayesian Varying Coefficient Kernel Machine Regression and Bayesian Kernel Machine Regression (BKMR) were used to evaluate metal mixture impacts on baseline and longitudinal changes in BP (from ages 4 to 11) and the development of elevated BP at age 11, respectively. BKMR results were compared using static versus percentile-based cutoffs to define elevated BP.

RESULTS

Molybdenum and lead were the mixture components most consistently associated with BP. J-shaped relationships were observed between molybdenum and both systolic and diastolic BP at age 4. Similar associations were identified for both molybdenum and lead in relation to elevated BP at age 11. For molybdenum concentrations above the inflection points (~ 40-80 μg/L), positive associations with BP at age 4 were stronger at high levels of lead. Lead was positively associated with BP measures at age 4, but only at high levels of molybdenum. Potential interactions between molybdenum and lead were also identified for BP at age 11, but were sensitive to the cutoffs used to define elevated BP.

CONCLUSIONS

Prenatal exposure to high levels of molybdenum and lead, particularly in combination, may contribute to higher BP at age 4. These early effects appear to persist throughout childhood, contributing to elevated BP in adolescence. Future studies are needed to identify the major sources of molybdenum and lead in this population.

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

BACKGROUND AND AIM

Hyperuricemia in adults is associated with cardiovascular risk factors. However, there is less data regarding this association in children and adolescents. Our purpose was to determine association between serum uric acid (SUA) and cardiovascular risk.

METHODS AND RESULTS

A fasting blood sample was collected from 1750 participants aged 6-17 years enrolled in a social project and public schools in Espírito Santo, Brazil. Internal cut-offs were generated to define high SUA (≥90th percentile of SUA concentration for sex and age group). Body mass index percentile (pBMI), body fat percentage (BFP) and muscle mass were determined by bioimpedance. Data are given as mean ± standard deviation. High SUA was associated with overweight/obesity (OR 3.7 CI 95% 2.7-5.0), high waist circumference (WC) (OR 3.9 CI 95% 2.9-5.4), low HDL (OR 2.0 CI 95% 1.5-2.8), high blood pressure (BP) (OR 1.8 CI 95% 1.1-3.2), high BFP (OR 4.1 CI 95% 2.7-6.4), metabolic syndrome (MetS) (OR 3.6 CI 95% 1.8-7.1) and insulin resistance (OR 1.7 CI 95% 1.1-2.7). Individuals in the fourth quartile of SUA, compared to those in the first quartile, showed higher age, pBMI, WC, BFP and muscle mass. Using a reference value of 5.5 mg/dL, the prevalence of hyperuricemia in the sample was 10.3% (CI 95% 8.9-11.7%).

CONCLUSION

Higher SUA values are associated with higher cardiovascular risk in childhood and adolescence. The main cardiovascular risk factors associated with hyperuricemia were overweight/obesity, high WC, dyslipidemia, high BFP, high BP, insulin resistance and MetS.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

[Hyperuricemia, gout and high cardiovascular risk - how to manage them in clinical practice]

In recent years, the relationship of hyperuricemia and gout with a high risk of cardiovascular disease has been widely discussed. Therefore, it is important to systematically examine patients in order to diagnose comorbidities, among which cardiovascular disease and its complications occupy a leading place and consider mandatory treatment of patients with hyperuricemia and gout with high cardiovascular risk with lowering drugs, which fully reflects the provisions of the latest European recommendations for the management and treatment of patients with gout.

[Comorbidity in gout and hyperuricemia: prevalence, causes, prospects of urate lowering therapy]

Nowadays, there is increased interest in the connection of gout and asymptomatic hyperuricemia with comorbid conditions such as diabetes mellitus, cardiovascular diseases, hypertension, chronic kidney disease and other. Studies conducted over the past few decades suggest that not only gout, but also asymptomatic hyperuricemia can significantly worsen the prognosis in patients with cardiovascular diseases, as the deposition of urate crystals can be both an immediate cause and a factor in the progression of renal failure. In that way, the timely appointment of urate - lowering therapy and achieving the target serum uric acid level can not only affect joint damage, but also can significantly slow the progression of life - threatening comorbid conditions.

High urate concentration is associated with elevated blood pressure in schoolchildren

Background Studies in adults have shown a relationship between high blood pressure and hyperuricemia, but few studies have investigated this association in children and adolescents. The aim of the present study was to associate urate concentration with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in schoolchildren. Methods This cross-sectional study used a sample of 2335 schoolchildren in basic education between 7 and 17 years old. Blood pressure was classified by percentile according to Brazilian parameters for sex and age, reclassified into two categories: normal and borderline/hypertension. Blood collection to obtain serum for urate concentration analysis was performed after a 12-h fast. Values above 5.5 mg/dL were considered hyperuricemia. Descriptive data were presented in frequency and percentage. Linear regression and Poisson regression (prevalence ratio [PR]) was used to test the association between urate concentration and blood pressure. Results Urate concentration was weakly associated with SBP (β: 0.05; 95% CI: 0.02-0.08) and DBP (β: 0.03; 95% CI: 0.01-0.05) z-scores. Schoolchildren with hyperuricemia had a higher prevalence of high SBP (PR: 1.12; p<0.001) and DBP (PR: 1.08; p<0.001). Conclusions Elevated urate concentration is associated with altered blood pressure in schoolchildren.

Application of metabolomics to preeclampsia diagnosis

Preeclampsia is a multifactorial disorder defined by hypertension and increased urinary protein excretion during pregnancy. It is a significant cause of maternal and neonatal deaths worldwide. Despite various research efforts to clarify pathogenies of preeclampsia and predict this disease before beginning of symptoms, the pathogenesis of preeclampsia is unclear. Early prediction and diagnosis of women at risk of preeclampsia has not markedly improved. Therefore, the objective of this study was to perform a review on metabolomic articles assessing predictive and diagnostic biomarkers of preeclampsia. Four electronic databases including PubMed/Medline, Web of Science, Sciencedirect, and Scopus were searched to identify studies of preeclampsia in humans using metabolomics from inception to March 2018. Twenty-one articles in a variety of biological specimens and analytical platforms were included in the present review. Metabolite profiles may assist in the diagnosis of preeclampsia and discrimination of its subtypes. Lipids and their related metabolites were the most generally detected metabolites. Although metabolomic biomarkers of preeclampsia are not routinely used, this review suggests that metabolomics has the potential to be developed into a clinical tool for preeclampsia diagnosis and could contribute to an improved understanding of disease mechanisms.

ABBREVIATIONS

PE: preeclampsia; sFlt-1: soluble FMS-like tyrosine kinase-1; PlGF: placental growth factor; GC-MS: gas chromatography-mass spectrometry; LC-MS: liquid chromatography-mass spectrometry; NMR: nuclear magnetic resonance spectroscopy; HMDB: human metabolome database; RCT: randomized control trial; e-PE: early-onset PE; l-PE: late-onset PE; PLS-DA: partial least-squares-discriminant analysis; CRL: crown-rump length; UtPI: uterine artery Doppler pulsatility index; BMI: body mass index; MAP: mean arterial pressure; OS: oxidative stress; PAPPA: plasma protein A; FTIR: Fourier transform infrared; BCAA: branched chain amino acids; Arg: arginine; NO: nitric oxide.

The association between serum uric acid and blood pressure in different age groups in a healthy Chinese cohort

High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants.A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricase-peroxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7 mg/dL in men and >6 mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis.The prevalence of hypertension and HUA increased with age (P < .001). Hypertension was more common in participants that had HUA than in those that did not (38.95% vs 30.16%, P = .02). Higher sUA was significantly associated with higher SBP and DBP in the 41- to 50-year-old participants (SBP, β = 0.35, P < .001; DBP, β = .29, P < .001; after adjustment for age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217-1.668, P < .001). There was no association between sUA concentration and SBP and DBP in the other age groups.In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension.

Impact of comorbidities on gout and hyperuricaemia: an update on prevalence and treatment options

Gout, the most prevalent inflammatory arthritis worldwide, is associated with cardiovascular and renal diseases, and is an independent predictor of premature death. The frequencies of obesity, chronic kidney disease (CKD), hypertension, type 2 diabetes, dyslipidaemias, cardiac diseases (including coronary heart disease, heart failure and atrial fibrillation), stroke and peripheral arterial disease have been repeatedly shown to be increased in gout. Therefore, the screening and care of these comorbidities as well as of cardiovascular risk factors are of outmost importance in patients with gout. Comorbidities, especially CKD, and drugs prescribed for their treatment, also impact gout management. Numerous epidemiological studies have shown the association of asymptomatic hyperuricaemia with the above-mentioned diseases and cardiovascular risk factors. Animal studies have also produced a mechanistic approach to the vascular toxicity of soluble urate. However, causality remains uncertain because confounders, reverse causality or common etiological factors might explain the epidemiological results. Additionally, these uncertainties remain unsolved despite recent studies using Mendelian randomisation or therapeutic approaches. Thus, large randomised placebo-controlled trials are still needed to assess the benefits of treating asymptomatic hyperuricaemia.