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

Mediative role of body mass index in cardiorespiratory fitness-associated vascular remodeling in youth

BACKGROUND

Data on fitness-associated arterial remodeling in children is limited. We assessed the relation between cardiorespiratory fitness (CRF) and intima-media thickness (IMT), diameter, IMT:diameter-ratio (IDR), and tensile stress of the common carotid artery (CCA) in 697 healthy German schoolchildren. Further, we explored how body mass index (BMI) may influence these associations.

METHODS

We measured the vascular parameters with a high-resolution ultrasound device. We determined CRF using the FITNESSGRAM® PACER test and calculated each child's allometrically scaled peak oxygen uptake capacity (VO2peak).

RESULTS

VO2peak, reflecting CRF, showed positive direct effects on IMT (girls: p < 0.001; boys: p = 0.02) and diameter in girls (p < 0.001). Considering BMI as a mediator, higher CRF was indirectly linked to decreases in IMT (girls: p = 0.04; boys: p = 0.02) and diameter (both p < 0.001), reflecting a competitive mediation. CRF indirectly mitigated the BMI-associated decrease in IDR (both p < 0.001) and increase in tensile stress (both p < 0.001) without affecting any of these parameters directly.

CONCLUSION

CRF appears to be linked to uniform arterial remodeling with balanced hemodynamics and to further alleviate BMI-associated, potentially adverse vascular alterations, highlighting its significant role in cardiovascular health in youth.

IMPACT

Data on CRF-associated arterial remodeling in youth is limited. Higher VO2peak, reflecting higher CRF, was positively associated with IMT in girls and boys and diameter in girls. These direct effects were counteracted by the indirect BMI-mediated effect of CRF on IMT and diameter, reflecting a competitive mediation. A higher CRF indirectly mitigated the BMI-associated decrease in IDR and increase in tensile stress without directly affecting any of these parameters. Our findings indicate homogenous remodeling and balanced hemodynamics with increasing CRF-and opposite effects with increasing BMI.

Associations between dietary patterns and serum uric acid concentrations in children and adolescents: a cross-sectional study

The serum uric acid (SUA) concentrations in children and adolescents in southeast coastal China are generally high. The relationship between diet and SUA in children and adolescents remains unclear. The objective of the study was to assess the associations between data-driven dietary patterns with SUA concentrations and hyperuricemia in Chinese children and adolescents and to explore the role of food components. This study involved 3383 participants aged 9 to 17 years from a representative nutrition and growth survey conducted in Shenzhen, a southeast coastal city in China. The dietary intake data, obtained from a validated food frequency questionnaire, were categorized into 19 food groups for factor analysis to derive dietary patterns. Weighted least squares regression was performed to examine the associations between dietary patterns and SUA concentrations, logistic regression was used to analyze the relationship between dietary patterns and hyperuricemia, and the relationship between food groups and food components with SUA concentrations was further analyzed. The potential dietary factors contributing to the associations between dietary patterns and SUA concentrations were explored by adjusting various food components. Six dietary patterns were identified by factor analysis, including an ultra-processed diet, plant-based nutritious diet, meat-based diet, soup/seafood/egg diet, vegetarian diet, and mushroom/animal organ diet. After adjusting for confounders, the meat-based diet exhibited a positive correlation with SUA concentrations (β = 4.89; 95% confidence interval (CI): 0.60-9.18; P = 0.03), while the vegetarian diet could reduce the risk of hyperuricemia (odds ratio = 0.88; 95% CI: 0.80-0.98; P = 0.02). In addition, dietary intake of poultry (g per d) (β = 0.09, 95% CI: 0.02, 0.16, P = 0.02), animal organs, blood (g per d) (β = 0.32, 95% CI: 0.12, 0.51, P = 0.002) and hypoxanthine (mg per d) (β = 0.03, 95% CI: 0.01, 0.06, P = 0.02) showed a significantly positive correlation with SUA concentrations, while that of vegetables (g per d) (β = -0.02, 95% CI: -0.03, -0.01, P = 0.03) showed a significantly negative correlation. In summary, for children and adolescents, it is recommended to increase vegetable intake and reduce animal-based food intake in order to control SUA concentration and prevent hyperuricemia. This study was registered at the China Clinical Trials Registry (ChiCTR2100051722).

Salivary uric acid reactivity and baseline associations with physiological stress response

Uric acid, an end product of the purinergic system, plays a role in several physiological systems that are responsive to stress. However, few studies have examined whether (1) uric acid concentrations change in response to acute stress, and (2) there are cross-system associations where uric acid might influence other physiological system responses to acute physical stress. The present study measured indices of the purinergic, hypothalamic-pituitary-adrenal axis, sympathetic, and parasympathetic systems (uric acid, cortisol, pre-ejection period, and root mean square of successive differences, respectively) in response to a standardized acute physical pain stressor, the cold pressor task. A diverse sample of participants (n = 67; mean age = 20.5 years, 52% female; 48% male) from a larger study completed anthropometric measurements and took part in a room temperature water task followed by the cold pressor task and sociodemographic questionnaires. Throughout the study, electrocardiography and impedance cardiography were measured continuously, and five saliva samples were collected that were later assayed for cortisol and uric acid. Descriptively, uric acid increased about 32 min following completion of the cold pressor. Resting uric acid concentrations were not associated with the autonomic nervous system response, but higher resting uric acid concentrations were associated with increased cortisol concentrations. Future research should examine the extent to which the purinergic system influences, and is influenced by, other types of stress and other physiological systems. The current findings highlight the potential role of an understudied biomarker and physiological system in the stress literature and have implications for basic and mechanistic researchers who study psychoneuroendocrinology, stress, and health.

Vascular diameter and intima-media thickness to diameter ratio values of the carotid artery in 642 healthy children

In children, arterial alterations occur with increased intima-media thickness as well as vascular diameter enlargement. Both conditions correlate with higher cardiovascular risk in adults, and both the array and proportion of these alterations are important hemodynamic parameters. In terms of functional adaptation processes, they influence several arterial wall properties as for example the shear and tensile stress of the vessel. There are no reference values for the vascular diameter and intima-media thickness/diameter ratio of the carotid artery in children. Therefore, this study aimed to assess vascular diameter, intima-media thickness/diameter ratio and related tensile stress values in children and to further investigate the influence of sex, age, body mass index, and blood pressure. The parameters were measured with high-resolution semi-automated ultrasound. Sex- and age-dependent values were calculated with the LMS method for a cross-sectional sample of 642 healthy, non-obese children aged 8-17 years. The mean vascular diameter was 5.45 ± 0.46 mm; the median intima-media thickness/diameter ratio was 0.085 (0.079-0.092); the median tensile stress was 105.4 (95.2-116.4) kPa. The vascular diameter and the tensile stress were higher, and the intima-media thickness/diameter ratio was lower in boys than in girls. In comparison to the normal weight study population the excludedobese children had a significantly higher diameter, a lower intima-media thickness/diameter ratio, and a higher tensile stress. In multiple regression analyses of diameter, intima-media thickness/diameter ratio, and tensile stress, all parameters were influenced by sex and body mass index. Furthermore, systolic and diastolic blood pressure significantly influenced the vascular diameter, and systolic blood pressure significantly influenced the intima-media thickness/diameter ratio. Conclusion: This study is the first to report values for the diameter, the intima-media thickness/diameter ratio of the carotid artery, and the related tensile stress allowing a more differentiated view of cardiovascular adaptations as it combines structural and functional vascular parameters. What is known: • Intima-media thickness and vascular diameter are related to a higher cardiovascular risk in adults • The intima-media thickness/diameter ratio gives information about hemodynamic and functional vessel adaptation What is new: • Values for vascular diameter, intima-media thickness/diameter ratio, and tensile stress of the carotid artery in children are presented in this study • Intima-media thickness as a surrogate marker for arterial health in children should be complemented by intima-media thickness/diameter ratio measurement.

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.

New Insights into the Roles of Monocytes/Macrophages in Cardiovascular Calcification Associated with Chronic Kidney Disease

Cardiovascular disease (CVD) is an important cause of death in patients with chronic kidney disease (CKD), and cardiovascular calcification (CVC) is one of the strongest predictors of CVD in this population. Cardiovascular calcification results from complex cellular interactions involving the endothelium, vascular/valvular cells (i.e., vascular smooth muscle cells, valvular interstitial cells and resident fibroblasts), and monocyte-derived macrophages. Indeed, the production of pro-inflammatory cytokines and oxidative stress by monocyte-derived macrophages is responsible for the osteogenic transformation and mineralization of vascular/valvular cells. However, monocytes/macrophages show the ability to modify their phenotype, and consequently their functions, when facing environmental modifications. This plasticity complicates efforts to understand the pathogenesis of CVC-particularly in a CKD setting, where both uraemic toxins and CKD treatment may affect monocyte/macrophage functions and thereby influence CVC. Here, we review (i) the mechanisms by which each monocyte/macrophage subset either promotes or prevents CVC, and (ii) how both uraemic toxins and CKD therapies might affect these monocyte/macrophage functions.

Increased C-Reactive Protein in Brazilian Children: Association with Cardiometabolic Risk and Metabolic Syndrome Components (PASE Study)

C-reactive protein (CRP) is a marker of subclinical inflammation that has been found to be associated with cardiovascular disease risk. However, few studies have investigated the relationship between CRP and cardiometabolic markers in a representative sample of prepubescent children. The objective was to evaluate the high-sensitive CRP (hs-CRP) and its association with traditional and nontraditional cardiometabolic risk factors, as well as metabolic syndrome (MetS) components in Brazilian children. This is a cross-sectional representative study, with participants of the Schoolchildren Health Assessment Survey (PASE). Children from 8 to 9 years old (n=350) enrolled in public and private schools in the municipality of Viçosa, Minas Gerais, Brazil, were evaluated. Sociodemographic evaluation was performed through a semistructured questionnaire. Anthropometric, body composition, clinical, and biochemical measures were analyzed for cardiometabolic risk assessment. The total mean of serum hs-CRP concentration was 0.62 (±1.44) mg/L. hs-CRP was significantly correlated with several anthropometric, biochemical, and clinical parameters in this population (P < 0.05). hs-CRP was positively associated with the accumulation of cardiometabolic risk factors and MetS components (P < 0.05). Children with excessive weight; abdominal obesity; increased gynoid and android body fat; low HDL-c; hyperglycemia; and elevated uric acid, homocysteine, and apoB had higher chances of presenting increased hs-CRP (P < 0.05). In this study, Brazilian children with cardiometabolic risk already presented elevated serum hs-CRP concentration. hs-CRP was associated with the increase of traditional and nontraditional cardiometabolic risk factors, as well as the accumulation of MetS components.

Examining the effects of uric acid-lowering on markers vascular of calcification and CKD-MBD; A post-hoc analysis of a randomized clinical trial

BACKGROUND

Chronic kidney disease (CKD)-mineral and bone disorder (MBD) is a systemic disorder that leads to vascular calcification and accelerated atherosclerosis. Uric acid has been shown to associate with vascular calcification and with carotid intima-media thickness (CIMT) and to suppress the 1 α-hydroxylase enzyme leading to lower 1,25-dihydroxyvitamin D (1,25(OH)2D) and higher intact parathyroid hormone (iPTH) levels. We hypothesized that lowering serum uric acid would reduce CIMT, calcification propensity, and circulating markers of CKD-MBD in CKD.

METHODS

This is a post-hoc analysis of a randomized, double-blind study of 80 patients with stage 3 CKD and hyperuricemia who received allopurinol or placebo for 12 weeks. CIMT and T50 were measured as markers of vascular disease and serum calcification propensity, respectively. The following markers of CKD-MBD were measured: serum calcium, phosphorus, vitamin D metabolites, iPTH, and fibroblast growth factor-23 (FGF-23). Expression of extra-renal 1α-hydroxylase was evaluated in endothelial cells of study participants.

FINDINGS

Allopurinol successfully lowered serum uric acid levels compared to placebo with an estimate of -3.3 mg/dL (95% C.I. -4.1,-2.5; p < 0.0001). After 12 weeks, however, we found no significant change in CIMT or serum T50. There was not a significant change in vitamin D metabolites, iPTH, FGF-23, or the expression of endothelial 1α-hydroxylase.

CONCLUSION

These data suggest that factors other than uric acid may play a more important role in the regulation of CKD- MBD including vascular calcification and vitamin D metabolism in patients with CKD.

Association of Breakfast Quality and Energy Density with Cardiometabolic Risk Factors in Overweight/Obese Children: Role of Physical Activity

There is a general belief that having breakfast is an important healthy lifestyle factor; however, there is scarce evidence on the influence of breakfast quality and energy density on cardiometabolic risk in children, as well as on the role of physical activity in this association. The aims of this paper were (i) to examine the associations of breakfast quality and energy density from both solids and beverages with cardiometabolic risk factors, and (ii) to explore whether physical activity levels may attenuate these relationships in children with overweight/obesity from two projects carried out in the north and south of Spain. Breakfast consumption, breakfast quality index (BQI) score, BEDs/BEDb (24 h-recalls and the KIDMED questionnaire), and physical activity (PA; accelerometry) were assessed, in 203 children aged 8–12 years who were overweight or obese. We measured body composition (Dual X-ray Absorptiometry), uric acid, blood pressure, lipid profile, gamma-glutamyl-transferase (GGT), glucose, and insulin, and calculated the HOMA and metabolic syndrome z-score. The BQI score was inversely associated with serum uric acid independently of a set of relevant confounders (β = −0.172, p = 0.028), but the relationship was attenuated after further controlling for total PA (p < 0.07). BEDs was positively associated with total and HDL cholesterol, and systolic blood pressure regardless of confounders (all p < 0.05), while BEDb was positively associated with HOMA in either active/inactive children (all p < 0.03). In conclusion, higher breakfast quality and lower breakfast energy density should be promoted in overweight/obesity children to improve their cardiometabolic health.

Prognostic factors for in-hospital mortality of patients hospitalized for acutely decompensated heart failure

Objectives Despite improved treatment during last 20 years, prognosis for patients hospitalized for acutely decompensated heart failure (ADHF) is poor and mortality rates reported for these patients are high. Laboratory results can assist clinicians in evaluation and triaging of patients on hospital admission, and are important for the medical decision-making and prognosis assessments. Recently, new guidelines for the diagnosis and treatment of acute and chronic HF patients were published introducing a new group of patients with mid-range left ventricular ejection fraction (LVEF). Methods In order to explore the prognostic value for the in-hospital mortality of ADHF patients we analyzed laboratory test results for 165 emergency hospitalized patients regarding the survival and LVEF. Results In-hospital mortality was 16%. Patients who died were older than survivals (p = 0.003). There were no differences in LVEF between survivals and non-survivals. Patients who survived had significantly lower N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT), uric acid, urea, creatinine, and red blood cell distribution width (RDW) than patients who died (p < 0.001). All these tests had a good discrimination power between survivals and non-survivals (p < 0.001), but their incremental addition to NT-proBNP didn't improve its overall prognostic value. There was only a very weak correlation between NT-proBNP concentrations and LVEF. Groups with different LVEF status showed significant difference in number of erythrocytes, RDW and hemoglobin concentrations. Conclusions NT-proBNP had the best discriminatory power between survivals and non-survivals. Some routine laboratory test results, like RDW, uric acid, urea, and creatinine, have potentially significant value.

Reduced peak stimulated growth hormone is associated with hyperuricemia in obese children and adolescents

The purpose of the study is to investigate whether reduced peak GH response to arginine-levodopa test is associated with hyperuricemia in obese children and adolescents. The study population consisted of a total sample of 78 obese and 30 normal-weight children and adolescents without known hypopituitarism. All participants underwent clinical examination and GH stimulation testing. IGF-1, lipid profile and other metabolic markers were assessed. The obese subjects were then divided into two groups according to the serum levels of uric acid. Results show that obese subjects had significantly lower peak GH, lower IGF-1 and similar height SDS than those in the control group. Children with hyperuricemia had significantly lower peak stimulated GH compared with non-hyperuricemia obese subjects. Results from logistic regression model showed that peak GH were negatively associated with hyperuricemia after controlling for age, gender, tanner stage, BMI SDS, IGF-1, blood pressure, HOMA-IR, lipids status. These data indicate that lower peak GH is positively associated with hyperuricemia in obese children and adolescents without known hypothalamic/pituitary disease after controlling BMI and insulin resistance, as well as other cardiometabolic risk factors.

Factors associated with carotid Intima media thickness and carotid plaque score in community-dwelling and non-diabetic individuals

Background

The carotid intima media thickness (cIMT) and carotid plaque score (cPS) are respective markers of early and late stage subclinical atherosclerosis. Relationships between some laboratory parameters and subclinical atherosclerosis are not yet clear in community dwelling individuals and non-diabetic subjects, so we try to elucidate these relationships and find a model to predict early and late stage subclinical atherosclerosis.

Methods

We examined relationships of the cIMT and cPS with different laboratory and demographic data of 331 subjects from a community-based prospective cohort study, using univariate and multivariate analyses.

Results

In regression models and after multiple adjustments, only systolic blood pressure (SBP), age, glycated hemoglobin (HBA1c), and waist circumference (WC) were determinants of the cIMT, and only age, SBP, HBA1c, and blood urea nitrogen (BUN) were determinants of a cPS of > 2 in all individuals. Only HBA1c lost its association with regard to predicting the cIMT in non-diabetic subjects.

Conclusions

HBA1c at > 5.9% can determine early and late stage subclinical atherosclerosis in community dwelling individuals, but only late stage subclinical atherosclerosis in non-diabetic subjects.

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.