Plasma and water fluoride levels and hyperuricemia among adolescents: A cross-sectional study of a nationally representative sample of the United States for 2013-2016

Associations of systemic inflammation and systemic immune inflammation with serum uric acid concentration and hyperuricemia risk: the mediating effect of body mass index

Background

With the development of lifestyle, elevated uric acid and hyperuricemia have become important factors affecting human health, but the biological mechanism and risk factors are still unclear.

Methods

A multi-stage, cross-sectional study of 41,136 adults from the NHANES 2003-2018 was conducted. Serum uric acid concentrations, platelet, neutrophil, lymphocyte, and monocyte counts were measured. The systemic inflammation response (SIRI) index and systemic immune-inflammatory (SII) index were calculated to reflect systemic inflammation and systemic immune inflammation. The height and weight data were obtained to assess body mass index (BMI). Generalized linear models were used to examine the relationships of SIRI and SII with uric acid and hyperuricemia risk, as well as the associations of SIRI and SII with BMI, and BMI with uric acid and hyperuricemia risk. Causal mediation effect model was used to assess the mediating effect of BMI in the relationships of SIRI, and SII with uric acid concentration and hyperuricemia risk.

Results

The prevalence of hyperuricemia in US adults is 19.78%. Positive associations were found in the relationships of SIRI and SII with uric acid level, hyperuricemia risk, and BMI, as well as the relationships of BMI with uric acid and hyperuricemia risk. Causal mediation effect model showed that BMI played an important mediating role in the relationships of SIRI, and SII with uric acid concentration and hyperuricemia risk, with the proportion of mediating effect ranging from 23.0% to 35.9%.

Conclusion

Exposure to higher SIRI and SII is associated with increased uric acid concentration and hyperuricemia risk in adults, and BMI plays an important mediating effect. Reducing systemic inflammation and systemic immune inflammation and proper weight control could be effective ways to reduce hyperuricemia prevalence and related health problems.

Associations of exposure to phthalate with serum uric acid and hyperuricemia risk, and the mediating role of systemic immune inflammation

BACKGROUND

Previous studies found that urinary phthalates (PAEs) metabolites may be associated with increased serum uric acid concentration and hyperuricemia risk. However, no population-based study has investigated the underlying biological mechanisms.

METHODS

This nationwide cross-sectional study analyzed the data from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Urinary PAEs metabolites were measured and 8 PAEs metabolites (MCPP, MECPP, MEHHP, MEOHP, MBzP, MiBP, MBP, and MEP) were incorporated into the analysis. Serum uric acid was determined and hyperuricemia cases were identified. Multi-variable generalized linear model, exposure-response (E-R) function and weighted quantile sum (WQS) regression were utilized to investigate the relationships of PAEs metabolites with serum uric acid concentration and hyperuricemia risk. Systemic immune inflammation (SII) was assessed using the SII index and its mediation effects were explored using causal mediation effect model.

RESULTS

Data from 10,633 US adults in the NHANES 2003-2018 was analyzed. Except for MEP, individual PAEs metabolite and total PAEs metabolites were associated with increased serum uric acid concentration and hyperuricemia risk. E-R function of PAEs metabolites with serum uric acid concentration and the risk of hyperuricemia showed significantly positive associations with most curves in a nearly linear relationship. WQS regression showed that the mixture of PAEs metabolites was related to elevated serum uric acid and hyperuricemia risk, and MBzP was identified as the most contributing PAEs metabolite. The causal mediation effect model found that SII significantly mediated the relationships of PAEs metabolites with serum uric acid and hyperuricemia risk.

CONCLUSION

Individual and mixture of urinary PAEs metabolites were associated with increased serum uric acid concentration and the risk of hyperuricemia. MBzP exhibited the highest contribution to the overall effects. SII alteration may be an important biological mechanism underlining the impact of PAEs metabolites on serum uric acid concentration and hyperuricemia risk.

A combined association of obesity, alanine aminotransferase and creatinine with hyperuricemia in youth aged 13-20 years

Background

Despite extensive research on hyperuricemia (HUA) in adults, there remains a dearth of studies examining this condition in youth. Consequently, our objective was to investigate the prevalence of HUA among youth in the United States, as well as identify the corresponding risk factors.

Methods

This study employed a nationally representative subsample of 1,051 youth aged 13-20 from the US National Health and Nutrition Examination Survey (NHANES) conducted between January 2017 and March 2020. Univariate and multivariate techniques were utilized to examine the association between HUA and obesity, dietary nutrients, liver and kidney function, glucose and lipid metabolism, inflammation, and other indicators in the adolescent population.

Results

The study encompassed a cohort of 1,051 youth aged 13-20 years, comprising 538 boys and 513 girls. The overall prevalence of HUA was found to be 7% (74 out of 1,051). Univariate analysis revealed that the HUA group exhibited greater age, body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). Additionally, the prevalence of obesity was significantly higher in the HUA group compared to the non- HUA group (all p < 0.05). Regarding biochemical indicators, the levels of urea nitrogen, creatinine (Cr), alanine aminotransferase (ALT), glutamic oxalic aminotransferase (AST), gamma-glutamyl transferase (GGT), total cholesterol (TC), triglyceride (TG), and HS C reactive protein (Hs CRP) were found to be significantly higher in the HUA group compared to the non-HUA group (all p < 0.05). Further analysis using binary logistics regression showed that BMI (p = 0.024, OR1.158, 95%CI1.019-1.316), ALT (p = 0.020, OR1.032, 95%CI1.005-1.059), and Cr (p = 0.016, OR1.028, 95%CI1.005-1.051) were identified as risk factors for HUA, after controlling for age, gender, BMI, WC, HC, WHR, ALT, AST, GGT, TG, TC, Cr, Hs CRP, and other indicators. Interestingly, neither univariate nor multivariate analysis found any association between dietary nutrients and the risk of HUA (all p > 0.05).

Conclusion

High BMI remains a major risk factor for HUA in US youth aged 13-20 years, and ALT and Cr levels should be closely monitored along with serum uric acid.

A Gender-, Age-, and Weight Status-Specific Analysis of the High Prevalence of Hyperuricemia Among Chinese Children and Adolescents with Obesity

Objective

To explore the gender-, age-, and weight status-specific prevalence of hyperuricemia (HUA) and its associated risk factors among Chinese children and adolescents with obesity.

Methods

A total of 1329 children aged 2-17 years, who were diagnosed with obesity and hospitalized in our center from January 2016 to December 2022 were recruited. They were divided into mild obesity, moderate obesity, and severe obesity groups. HUA was defined as fasting serum uric acid level >420 μmol/L for boys and >360 μmol/L for girls. Multivariate logistic regression analyses were performed to identify risk factors for HUA.

Results

The highest proportion of hospitalized obese children was aged 10-13 years comprising 677 (50.9%) followed by those aged 6-9 years comprising 348 (26.2%) whereas the least proportion was aged 2-5 years comprising 76 (5.7%). The above differences in age distribution were still present in subgroup analyses according to weight status. Most hospitalized obese children were boys (64.7%), especially in the severe obesity group (75.0%). The overall estimated prevalence of HUA in obese children was 54.8%. It presented a gradual increase trend over the last 7 years, with more rapidly in boys than in girls. Subgroup analysis by weight status showed that the prevalence of HUA was higher in children with moderate obesity (64.3%) and severe obesity (64.2%) when compared with mild obesity (48.2%) (P all<0.01). Boys reached a relatively high HUA incidence level (≥60%) at age 12, which occurred about 2 years later than in girls (age 10). With 12 years as the cut-off point, a high prevalence of HUA (≥60%) was observed in both genders. Multivariable logistic regression analyses showed that boy (OR=2.844, 95% CI 2.024-3.998), age (OR=1.253, 95% CI 1.155-1.360), BMI-Z score (OR=2.132, 95% CI 1.438-3.162), fasting blood glucose (OR=0.907, 95% CI 0.860-0.956), phosphorus (OR=4.123, 95% CI 2.349-7.239), alkaline phosphatase (OR=1.002, 95% CI 1.001-1.004), creatinine (OR=1.067, 95% CI 1.037-1.098), urea nitrogen (OR=1.193, 95% CI 1.032-1.378), aspartate aminotransferase (OR=1.016, 95% CI 1.002-1.030), triglycerides (OR=1.339, 95% CI 1.075-1.667), and high-density lipoprotein cholesterol (OR=0.381, 95% CI 0.160-0.910) were independently associated with odds of HUA (P all<0.05).

Conclusion

The prevalence of HUA in Chinese obese children and adolescents is unexpectedly high. Childhood HUA was significantly associated with obesity. Gender and age differences were observed in the association between childhood obesity and HUA. Obese children aged ≥12 years should be focused on screening the risk of HUA.

Analysis of the prevalence and influencing factors of hyperuricemia in children and adolescents aged 6-17 years in northeastern Sichuan Province

OBJECTIVE

To investigate the factors influencing hyperuricemia in children and adolescents and to provide a scientific basis for early prevention and treatment.

METHODS

A retrospective study (2017-2021) of the prevalence of hyperuricemia in children and adolescents was conducted, and the factors influencing hyperuricemia were analyzed by multi-factor logistic regression.

RESULTS

The overall prevalence of hyperuricemia in children and adolescents aged 6-17 years in northeast Sichuan Province was 55.12% (8676/15,739), of which 60.68% (5699/9392) in boys and 46.90% (2977/6347) in girls; the prevalence of hyperuricemia from 2017 to 2021 was 52.40% ( 1540/2939), 52.56% (1642/3124), 52.11% (1825/3502), 58.33% (1691/2899), and 60.40% (1978/3275), respectively; the prevalence rates of 6-12 years old were 48.92% (864/1766), 50.46% (769/1524), and 52.73% (685/1299), 56.99% (693/1216), 35.46% (444/1252), 46.33% (524/1131), 60.50% (720/1190), and 66.82% (739/1106), 58.95% (652/1106), and 62.17% (761/1106) for 13-17 years old, respectively, 62.17% (761/1224), 63.19% (855/1353), and 61.70% (970/1572), respectively. Logistic regression showed that the prevalence of male (OR = 1.451, 95% CI 1.034 to 2.035, p = 0.031), age (OR = 1.074, 95% CI 1.024 to 1.126, p = 0.003), overweight/obesity (OR = 1.733, 95% CI 1.204∼2.494, p = 0.003), blood creatinine (OR = 1.018, 95% CI 1.005∼1.031, p = 0.007), triglycerides (OR = 1.450, 95% CI 1.065∼1.972, p = 0.018), blood calcium (OR = 6.792, 95% CI 1.373∼33.594, p = 0.019), and systolic blood pressure (OR = 1.037, 95% CI 1.018∼1.057, p < 0.001) were influential factors for the development of hyperuricemia.

CONCLUSION

The prevalence of hyperuricemia was higher in children and adolescents aged 6-17 years in northeastern Sichuan Province, with a higher prevalence in boys than in girls, and the prevalence increased with age.

Association between fluoride exposure and blood pressure in children and adolescents aged 6 to19 years in the United States: NHANES, 2013-2016

To examine the association between fluoride exposure and childhood blood pressure (BP), we used data involving 3260 subjects participating in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016. Both plasma and water fluoride concentrations were measured using the ion-specific electrode. Outcome variables were systolic blood pressure (SBP) and diastolic blood pressure (DBP). For a 1-mg/L increase in water fluoride concentration, the participants' SBP decreased by 0.473 mm Hg (95% CI: -0.860, -0.087). Specifically, inverse associations were found between water fluoride and SBP in girls (β= -0.423, 95% CI: -0.886, -0.021), adolescents (β= -0.623, 95% CI: -0.975, -0.272), and non-Hispanic whites (β= -0.694, 95% CI: -1.237, -0.151). Also, every 1-μmol/L increase in plasma fluoride concentration was associated with a 1.183 mm Hg decrease in SBP among other races (95% CI: -2.258, -0.108). This study suggested that fluoride exposure may affect childhood blood pressure.

Association between urinary phthalate metabolites and hyperuricemia in US adults

Phthalate metabolites have been detected from urine in most of the US population and have become a public health problem. However, the association between phthalate metabolites and hyperuricemia has been scarcely studied so far. We aimed to evaluate if phthalate metabolites were associated with hyperuricemia in US adults. A total of 8816 participants of the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018 were included in our study. We used multivariable logistic regression models and restricted cubic spline (RCS) models to explore the association between urinary phthalate metabolites and hyperuricemia. Then, stratified analyses were conducted by sex and age. The prevalence of hyperuricemia in the study sample was 20.35%. Compared to the lowest quantile, the odds ratios (ORs) and 95% confidence intervals (CIs) for hyperuricemia were all statistically significant in following phthalate metabolites: 1.34 (1.13-1.58) for the second quartile in Mono-isobutyl phthalate (MiBP), 1.21 (1.01-1.46) for the highest quartile in Mono-(carboxyoctyl) phthalate (MCOP), 0.66 (0.56-0.76) for the second quartile in Mono-(2-ethyl)-hexyl phthalate (MEHP), 1.22 (1.05-1.43) for quartile 2 in Benzyl butyl phthalate (ΣBBP), and 1.43 (1.22-1.66) for the third quartile in high molecular-weight phthalate (ΣHigh MWP), respectively. Our results indicate that several urinary phthalate metabolites are positively associated with the odds of hyperuricemia.

The Association between Water Consumption and Hyperuricemia and Its Relation with Early Arterial Aging in Middle-Aged Lithuanian Metabolic Patients

BACKGROUND

Hyperuricemia is well-known as an independent risk factor for the development of hypertension, metabolic syndrome, and cardiovascular disease. Water is essential to most bodily functions, and its consumption rates appear to decline with age. The aim was to evaluate the influence of water intake on early vascular aging in metabolic middle-aged patients with hyperuricemia.

MATERIALS AND METHODS

The study included 241 men aged 40-55 years and 420 women aged 50-65 years from the Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program. Anthropometric characteristics, blood pressure, laboratory testing, and the specialized nutrition profile questionnaire were evaluated. Carotid-femoral pulse wave velocity (cfPWV), assessed using applanation tonometry, was evaluated as an early vascular aging parameter in patients with hyperuricemia and with normal serum uric acid (sUA) levels.

RESULTS

72.6% of men and 83.1% of women drink insufficient amounts of water (less than 1.5 L per day). However, our results showed statistically significant relationships only among a group of women. The women in the hyperuricemic group had a higher cfPWV than women with normal sUA levels. In hyperuricemic women, drinking less than 0.5 L per day in combination with other risk factors, such as age, increasing fasting glucose, and systolic blood pressure, was statistically significantly associated with an increased cfPWV (R² = 0.45, Adj. R² = 0.42, p < 0.001).

CONCLUSION

Drinking an insufficient amount of water daily is associated with increased arterial stiffness and has a negative effect on vascular health in metabolic women with hyperuricemia.

Prevalence and related factors of hyperuricaemia in Chinese children and adolescents: a pooled analysis of 11 population-based studies

BACKGROUND AND AIMS

Hyperuricaemia can lead to gout and is associated with an increased risk of cardiometabolic disease. We aimed to investigate the prevalence of hyperuricaemia and its related factors in Chinese children and adolescents.

METHODS

We pooled data from 11 population-based studies comprising 54,580 participants aged 3-19 years. The sex- and age-standardized prevalence of hyperuricaemia was estimated overall and by sex, age, weight status, geographic region and survey year.

RESULTS

Serum uric acid (SUA) increased gradually from 3 to 11 years with no significant sex difference, and then increased dramatically during 11-15 years. The estimated overall prevalence of hyperuricaemia was 23.3% (26.6% in boys and 19.8% in girls, p < .001). The prevalence increased with growing age (3.7, 9.8, 15.8, 35.5 and 31.7% among children aged 3-5, 6-8, 9-11, 12-15 and 16-19 years, respectively, p for trend < .001) and with increasing weight status (18.2, 37.6, 50.6 and 64.5% among children with non-overweight, overweight, obesity and extreme obesity, respectively, p for trend < .001). The prevalence was higher in North than in South (24.2 vs. 19.7%, p < .001), and increased markedly from 16.7% during 2009-2015 to 24.8% during 2016-2019. In multivariable regression analyses, sex, age, obesity, region and survey year were independently associated with odds of hyperuricaemia.

CONCLUSIONS

The prevalence of hyperuricaemia in Chinese children and adolescents is unexpectedly high. The findings suggest an urgent need to implement effective interventions to reduce risk of hyperuricaemia in Chinese youths.KEY MESSAGESQuestion: What is the prevalence of hyperuricaemia in Chinese children and adolescents?Findings: In this large pooled cross-sectional study comprising >50,000 children and adolescents aged 3-19 years, we found that the prevalence of hyperuricaemia was high in overall population and subgroups of sex, age, obesity, region and survey year.Meaning: Our findings indicate that hyperuricaemia is an important health problem in Chinese children and adolescents, and effective intervention strategies are needed to reduce its burden.

Role of renal function in the association of drinking water fluoride and plasma fluoride among adolescents in the United States: NHANES, 2013-2016

CONTEXT

While fluoride has been added to drinking water and dental products for decades in order to prevent tooth decay, there are growing concerns about its potential toxicity. Given that fluoride is primarily excreted in urine, an important question that has not been examined is whether among those whose drinking water is fluoridated, impaired renal function is associated with higher levels of circulating fluoride.

OBJECTIVE

To examine the association between drinking water and plasma fluoride and its modification by renal function.

DESIGN, SETTING, AND PARTICIPANTS

Participants in the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2016 with measures of fluoride in plasma and drinking water and renal function. These measures were only available in adolescent age 12-19 years.

OUTCOMES

Plasma fluoride levels and their modification by strata of renal function, measured by the estimated glomerular filtration rate (eGFR).

RESULTS

Among 1841 healthy adolescents, a 10 ml/min/1.73 m (Penman et al., 1997) lower eGFR and a 1 mg/L higher drinking water fluoride concentration were associated with a 0.02 (95%CI -0.02, -0.03) umol/L and 0.23 (95%CI 0.15,0.30) umol/L higher adjusted plasma fluoride level, respectively. The association of water and plasma fluoride levels was most robust among those with lower renal function (multiplicative interaction p value < 0.001). For adolescents in the lowest eGFR quartile, a 1 mg/L higher drinking water fluoride concentration was associated with a 0.35 (95%CI 0.21,0.48) umol/L higher plasma fluoride level, compared to 0.20 (95%CI 0.14,0.26) umol/L in the highest eGFR quartile. Restriction to those with measurable plasma fluoride levels yielded similar results.

CONCLUSIONS

Water fluoridation results in higher plasma fluoride levels in those with lower renal function. How routine water fluoridation may affect the many millions of Americans with Chronic Kidney Disease, who are particularly susceptible to heavy metal and mineral accumulation, needs to be further investigated.

Hyperuricemia and Associated Factors in Children with Chronic Kidney Disease: A Cross-Sectional Study

Background: Hyperuricemia is increasingly recognized as a risk factor for chronic kidney disease (CKD) just in adults. The purpose of this study was to investigate the clinical characteristics of hyperuricemia and its associated factors in Chinese children with CKD at a single center. Methods: A cross-sectional study of 170 CKD children collected from the Department of Nephrology, The Zhejiang University Children’s Hospital was conducted. The clinical data, including anthropometric data, blood pressure measurements, and biochemical parameters, were recorded and analyzed retrospectively. The factors associated with hyperuricemia in CKD children were evaluated by Pearson and Spearman correlation analysis and multiple logistic regression analysis. Results: The mean age was 9.79 ± 4.10 years, and 72 (42.35%) were girls. Higher blood urea nitrogen (BUN), serum creatinine, cystatin C, D-dimer, lower hemoglobin, albumin, and estimated glomerular filtration rate (eGFR) were significantly associated with higher serum uric acid (SUA). In multiple logistic regression analysis, anemia and higher BUN were both positively associated factors, whereas eGFR ≥ 90 mL/min/1.73 m² was a negatively associated factor for subjects with SUA ≥ 390 µmol/L (6.5 mg/dL). Conclusions: SUA was significantly associated with kidney risk factors in CKD children. Monitoring and controlling SUA, Hb, BUN, and Scr levels in CKD children may help to prevent the progression of CKD.