Association between serum uric acid and obesity in Chinese adults: a 9-year longitudinal data analysis

Consensus gene co-expression analysis across multiple intestinal tissues to identify key genes and pathways associated with abdominal fat deposition in broilers

1. Abdominal fat deposition (AFD) is regulated by multiple intestinal tissues, and changes in the function of intestinal tissues are associated with AFD. Currently, integration of transcriptomic data across multiple intestinal tissues to explore excessive AFD has rarely been reported in broilers.2. In this study, a consensus gene co-expression network across the duodenum, jejunum, ileum and caecum of high- and low-abdominal fat broiler lines (HL and LL) was constructed using a publicly available transcriptomic data set. Combining the results of functional enrichment analyses and differential gene expression analyses, this investigated the genes and biological pathways across the four intestinal tissues that might influence AFD.3. In one expression module, NDUFA5, NDUFS6, NDUFA4, NDUFS4, ATP5H, ATP5J and ATP5C1 were significantly enriched in the oxidative phosphorylation pathway, with GPX2 and GSR significantly enriched in the glutathione metabolism pathway. These genes were significantly downregulated in the four intestinal tissues of the HL compared to LL chickens, which may be associated with AFD by increasing intestinal permeability.4. Lipid metabolism relevant genes were identified in other modules (ALDH7A1, ACSBG1, THEM4 and DECR1), which may be linked to AFD through regulation of lipid metabolism. Interestingly, in the first module, 12 genes were significantly enriched in the proteasome pathway and significantly downregulated in the four intestinal tissues in HL birds compared to LL birds, indicating a link between the proteasome and AFD.

Association between obesity phenotypes and dietary patterns: A two-step cluster analysis based on the China multi-ethnic cohort study

OBJECTIVE

This study aimed to explore obesity phenotypes and investigate their association with dietary patterns.

METHODS

Data were obtained from the baseline survey conducted in the China Multi-Ethnic Cohort Study from July 2018 to August 2019. All participants with a body mass index of at least 24 kg/m2 were enrolled and underwent a questionnaire survey, physical examination, and clinical laboratory tests. A two-step cluster analysis was employed to classify the participants into phenotypes. Dietary information was collected using the food frequency questionnaire, and principal component analysis was conducted to identify distinct dietary patterns.

RESULTS

We analyzed the data of 8757 participants. They were categorized based on demographic characteristics, biochemical indicators, and anthropometric measurements into two distinct clusters identified as metabolically healthy obesity and metabolically unhealthy obesity (MUO). Key predictors included serum uric acid, sex, and diastolic blood pressure. Subgroup analysis by sex identified three distinct clusters within both male and female participants. The MUO group had the highest prevalence of a range of chronic noncommunicable diseases. The analysis uncovered three unique dietary patterns among participants classified as the premium protein, rice-oil-red meat, and oil-salt patterns. Notably, the MUO subgroup demonstrated significantly higher factor scores for both the rice-oil-red meat and oil-salt patterns.

CONCLUSIONS

Obesity phenotypes are closely related to metabolic and demographic characteristics, with serum uric acid being a significant factor in categorizing the metabolic states of obesity. The rice-oil-red meat and oil-salt patterns may be related to the metabolic status of individuals with obesity.

Association of uric acid with body adiposity and biochemical parameters in kidney transplant patients

BACKGROUND

Obesity and various biochemical parameters, including triglycerides, cholesterol, glucose, C-reactive protein, and estimated glomerular filtration rate, have been linked to elevated uric acid (UA) levels in populations with normal kidney function due to decreased UA excretion and/or increased UA synthesis. However, it remains unclear whether all these factors exhibit similar associations with UA levels in clinical populations characterized by compromised renal function, such as kidney transplant patients (KTPs).

OBJECTIVE

To evaluate whether serum UA levels are associated with body adiposity and biochemical parameters in KTPs.

METHODS

A cross-sectional study involving 113 KTPs was conducted. Body fat was estimated using bioelectrical impedance, and waist circumference was measured using an inelastic tape. Serum levels of UA, creatinine, glucose, triglycerides, total cholesterol, and its fractions were measured using the colorimetric method. C-reactive protein levels were assessed using the immunoturbidimetric method, and urea levels were determined via enzymatic kinetics. Glomerular filtration rate was estimated using the chronic kidney disease epidemiology collaboration equation. Linear regression analyses were employed to assess the association between serum UA levels and body adiposity as well as biochemical parameters, while adjusting for confounders.

RESULTS

Serum UA levels exhibited a positive association with creatinine (β = 0.402; p = 0.013) and urea (β = 0.024; p = 0.001), while demonstrating an inverse association with estimated glomerular filtration rate (β = -0.030; p < 0.001). However, serum UA levels were not significantly associated with fat mass (both in kilograms and as a percentage), waist circumference, triglycerides, C-reactive protein, glucose, HDL cholesterol, LDL cholesterol, VLDL cholesterol, or total cholesterol.

CONCLUSION

Serum UA levels are only associated with biochemical parameters linked to renal function in KTPs. Consequently, in individuals with suboptimal renal function, such as KTPs, UA does not exhibit associations with other biochemical parameters and body adiposity, as commonly observed in non-renal disease populations.

Relationship between serum vitamin C and serum uric acid in people with different BMIs: results from the NHANES 2017-2018 and Mendelian randomization study

Objective

To examine the association of overweight/obesity and serum vitamin C (serum VC) with serum uric acid (SUA) and to assess causality using Mendelian randomization (MR).

Methods

4,772 participants from the National Health and Nutrition Examination Survey (NHANES), 2017-2018 were included in this study. Multivariate linear regression, variance inflation factor and quantile regression were used to analyze the relationships between overweight/obesity and serum VC and SUA levels. Secondly, Mendelian randomization (MR) was utilized to mitigate bias and prevent reverse causality in the observational study. Genetic variants associated with obesity (N = 13,848), vitamin C levels (N = 64,979) and serum uric acid levels (N = 343,836) were sourced from the most extensive genome-wide association studies (GWAS). The primary analytical method employed was inverse variance weighted (IVW).

Results

Based on the observational study, BMI was positively associated with SUA (β = 0.06, 95% CI: 0.05 to 0.07, p < 0.001) and serum VC was negatively associated with SUA (β = -0.14, 95% CI: -0.23 to -0.04, p = 0.005). In individuals with overweight/obesity (BMI > =25), the negative effects of serum VC on SUA enhanced with increasing serum VC. High serum VC level (Q4 level, above 1.19 mg/dL) reduced SUA (β = -0.30, 95% CI: -0.47 to -0.14, p < 0.001) in individuals with overweight/obesity compared to low serum VC level (Q1 level, below 0.54 mg/dL). IVW-MR analysis revealed a significant association between SUA levels and genetically elevated levels of VC (β = -0.03, 95% CI: -0.06 to -0.00, p = 0.029) and obesity (β = 0.06, 95% CI: 0.04 to 0.07, p < 0.001).

Conclusion

Cross-sectional observational analysis revealed that BMI exhibited a positive correlation with SUA levels and that serum VC was negatively correlated with SUA levels; moreover, moderate serum VC can reduce SUA, especially in individuals with overweight/obesity. There was evidence indicating a causal effect of VC and obesity on SUA. It highlights the importance of VC in the management of SUA levels, particularly in overweight/obese individuals. The findings might be helpful for the management of high SUA levels.

Non-Pharmacological Treatment for Cardiovascular Risk Prevention in Children and Adolescents with Obesity

In younger generations, excess weight has reached very alarming levels. Excess weight in adults is associated with increased mortality and morbidity from cardiovascular disease. However, it is not easy to distinguish to what extent these effects are the result of obesity itself or how much is due to the various cardiovascular risk factors that often accompany excess weight. Several risk factors, such as hypertension, dyslipidemia, hyperuricemia, glucose intolerance, and type 2 diabetes mellitus, are already present in pediatric age. Therefore, early intervention with the goal of correcting and/or eliminating them is particularly important. In the child and adolescent with obesity, the first approach to achieve weight reduction and correct the risk factors associated with severe excess weight should always be non-pharmacologic and based on changing poor eating habits and unhealthy lifestyles. The purpose of this review is to give an update on non-pharmacological interventions to be implemented for cardiovascular prevention in children and adolescents with obesity, and their effectiveness. In particular, interventions targeting each individual cardiovascular risk factor will be discussed.

Mediation effect of metabolic factors and inflammation on the association of serum uric acid with serum proprotein convertase subtilisin/kexin type 9 levels

BACKGROUND

The association between serum uric acid (SUA) levels and serum PCSK9 levels has not yet been uncovered. This study aimed to explore the potential link between SUA levels and serum PCSK9 levels and quantify the mediating effect of metabolic factors and inflammation in Chinese adults. Furthermore, assessed whether gender differences modified this association.

METHODS

In total, 2624 participants were enrolled and categorized based on their serum UA levels as the hypouricemic (n = 432) and normouricemic group (n = 2192). Stepwise multivariable regression analysis, binary logistic regression analysis and mediation analyses were performed.

RESULTS

Participants with hyperuricemia had higher serum PCSK9 levels than those with normouricemia (73.74 ± 30.25 vs 68.55 ± 29.01 ng/ml, P < 0.05), especially in women (69.11 ± 28.84 vs 87.86 ± 27.90 ng/ml, P < 0.001). SUA levels were positively associated with serum PCSK9 levels in all participants (r = 0.06, P < 0.01) and in women (r = 0.22, P < 0.01), but not in men (r = 0.03, P = 0.18). Multiple linear regression and binary logistic regression analyses indicated that serum PCSK9 levels were significantly correlated with SUA levels and hyperuricemia in women. However, when the model was adjusted for triglyceride (TG), the associations of serum PCSK9 levels with SUA levels and hyperuricemia disappeared. In mediation analyses, TG, low-density lipoprotein cholesterol (LDL-C), body mass index(BMI), total cholesterol (TC), white blood cell count and neutrophil count explained 35.08 %, 20.58 %,19.99 %, 14.37 %, 7.10 % and 3.24 % of SUA levels association with serum PCSK9 levels, respectively.

CONCLUSION

Serum PCSK9 levels are positively associated with SUA levels in women. Furthermore, this association is partially mediated through metabolic factors and inflammation.

The Prevalence of Hyperuricemia and the Association Between Hyperuricemia and Age in Patients with Psychiatric Disorders to a General Hospital: A Cross-Section Study

Purpose

In clinical work, it has been found that the prevalence of hyperuricemia (HUA) is significantly higher in younger patients with psychiatric disorders, but there are few studies in this area. The present study aims to evaluate the prevalence of HUA and the relationship between the HUA and age in hospitalized patients with psychiatric disorders in the real world, and to provide a theoretical basis for clinical staff to pay attention to the metabolic indicators of younger patients and for future related studies.

Methods

This is a cross-sectional evaluation of a cohort of 1761 patients with psychiatric disorders of hospitalized. The categories of disorders designed for study included: Depression, Bipolar disorder, Schizophrenia, Anxiety, Obsessive-Compulsive disorder, Acute and transient psychotic disorder, Dissociative(conversion) disorders, Conduct disorders and Tic disorders. In addition, based on age, the participants are stratified into three groups. The authors used Kruskal-Wallis tests, chi-square tests, and multiple linear logistic regression to verify the relationship between HUA and age among hospitalized patients with psychiatric disorders.

Results

Overall, the estimated prevalence of HUA was 35.4%. The prevalence of HUA was significantly higher in individuals with 17 years and under compared to those with 45 years and above (P < 0.001). After adjusting for confounders, the prevalence of HUA remained higher at 17 years and under than at 45 years and above. Bipolar disorder can lead to an increased prevalence of HUA (P<0.05).

Conclusion

The prevalence of HUA was higher in hospitalized patients with psychiatric disorders, and the prevalence was inversely proportional to age.

Serum uric acid did not affect embryonic and pregnancy outcomes in women without PCOS during IVF procedures

Objectives

Serum uric acid (UA) levels are associated with many systemic diseases. A previous study confirmed the association between high serum uric acid levels and poor prognosis of in vitro fertilization (IVF) treatment in polycystic ovary syndrome (PCOS) patients. This study aimed to explore the correlation between serum uric acid levels and reproductive outcomes in patients without PCOS.

Methods

A retrospective study that included 1057 patients who underwent pre-implantation genetic testing for monogenic disorders (PGT-M) treatment from January 2013 to December 2020 was conducted. The study population was further divided into 3 groups according to serum UA levels: the ≤250 μmol/L group, the 251-360 μmol/L group, and the >360 μmol/L group. The controlled ovarian hyperstimulation (COH) treatment outcomes, embryonic treatment outcomes and pregnancy outcomes of the first frozen embryo transfer (FET) cycle were compared among groups. Multivariable linear regression and binary regression were applied to detect the association between IVF outcomes and serum uric acid levels.

Results

The number of retrieved oocytes, fertilization rate, viable embryo rate, blastocyst formation rate and euploid rate were not associated with serum uric acid levels. The mature oocyte rate was negatively correlated with serum uric acid levels. The pregnancy outcomes of the first FET cycle were also not associated with serum uric acid levels. After adjustment for BMI, the perinatal outcomes were not associated with serum uric acid levels.

Conclusion

IVF treatment outcomes were not associated with serum uric acid levels in patients without PCOS.

Bean and Nut Intake Were Protective Factors for Comorbid Hypertension and Hyperuricemia in Chinese Adults: Results from China Nutrition and Health Surveillance (2015-2017)

This study aimed to describe the prevalence of comorbid hypertension and hyperuricemia (HH) and detected the dietary factors for HH in Chinese adults aged 18 to 64 years. All of the data were collected from the China Nutrition and Health Surveillance 2015-2017, with a stratified, multistage, random sampling method on a national scale. A total of 52,627 adult participants aged 18~64 years from the CNHS 2015-2017 were included in this study. HH was identified as SUA level cut-offs for males and females of 420 μmol/L and 360 μmol/L, respectively, with mean systolic blood pressure ≥140 mmHg and/or mean diastolic blood pressure ≥ 90 mmHg and/or received antihypertensive treatment within two weeks. The differences in HH prevalence between or among the subgroups were compared by the Rao-Scott chi-square test. The correlations between HH and covariates or metabolic factors were detected by a weighted two-level multivariate survey logistic regression. The total weighted sufficient intake ratios of beans and nuts, vegetables, and red meat were 59.1%, 46.6%, and 64.8%, respectively. The weighted prevalence of HH in the total participants was 4.7% (95% CI: 4.3-5.0%). The positive effects of bean and nut on HH were observed. The participants who had sufficient bean and nut intake showed lower risk for HH (for the total participants: OR = 0.734, 95% CI = 0.611-0.881). The prevalence of HH might have been a public health problem, and bean and nut intake might be a protective factor for HH in the Chinese population.

Prevalence of hyperuricaemia among adults from Ningxia Hui Autonomous Region, China: a cross-sectional study

OBJECTIVE

This study aimed to estimate the prevalence of hyperuricaemia (HUA) and investigate its risk factors in the general adult population of Ningxia Hui Autonomous Region (NHAR), China.

DESIGN

Cross-sectional study.

SETTING

Survey of cardiovascular disorders and their related risk factors in NHAR, China.

PARTICIPANTS

10 803 permanent residents aged 18 and older.

MAIN OUTCOME MEASURES

HUA was defined as serum uric acid levels >420 µmol/L for men and >360 µmol/L for women.

RESULTS

The overall prevalence of HUA in NHAR adults was 19.81% (95% CI 19.06 to 20.57), with prevalence values of 24.91% (95% CI 23.70 to 26.14) in men and 15.58% (95% CI 14.66 to 16.53, p<0.001) in women. The prevalence of HUA was higher in urban residents than in rural residents (23.26% vs 17.02%, p<0.001). HUA prevalence was relatively high in individuals younger than 30 years for both men and women, then decreased with age, and began to increase at the age of 40 for women and 60 for men. Higher level of education, being overweight or obese, alcohol consumption, hypertension, diabetes, higher triglycerides, higher total cholesterol and poorer renal function were associated with an increased risk of HUA.

CONCLUSIONS

HUA prevalence is high among adults in NHAR. Young adults under 30 years and women over 50 years were identified as populations at high risk for HUA. Further attention ought to be placed to promoting healthy diets and implementing early interventions to manage dyslipidaemia, obesity and blood glucose level, as well as advocating for moderation of alcohol consumption.

Associations between obesity parameters and hyperuricemia by sex, age, and diabetes mellitus: A nationwide study in Korea

OBJECTIVE

We investigated the associations between obesity parameters and the risk of hyperuricemia among Korean adults by sex, age, and diabetes mellitus status.

METHODS

This study analyzed data from 17,753 adults from the Korea National Health and Nutrition Examination Survey (KNHANES) 2016-2018. Multivariable logistic regression analyses were conducted to examine the associations of body mass index (BMI), waist circumference (WC), and general and abdominal obesity with the risk of hyperuricemia (serum uric acid ≥7.0 mg/dL in men and ≥6.0 mg/dL in women).

RESULTS

Of all the participants, 12.7% (n = 2256) had hyperuricemia. The age-adjusted mean serum uric acid levels increased significantly with increasing BMI and WC (P for trend <0.001). The adjusted odds ratios (ORs) of hyperuricemia increased as BMI and WC increased in both sexes (P for trend <0.001). General (OR 1.98, 95% confidence interval [CI]: 1.69-2.32) and abdominal (OR 2.21, 95% CI: 1.89-2.58) obesity in men and general (OR 3.26, 95% CI: 2.60-4.09) and abdominal (OR 3.43, 95% CI: 2.69-4.37) obesity in women were associated with higher risks of hyperuricemia. These associations were prominent in women. The association between abdominal obesity and hyperuricemia persisted after additional adjustments for BMI in both sexes. Significant interactions were observed in younger adults and individuals without diabetes mellitus.

CONCLUSION

Increased BMI and WC, and general and abdominal obesity, may be important risk factors for hyperuricemia in both sexes. Women, young adults, and individuals without diabetes mellitus require particular attention to prevent obesity and hyperuricemia.

The Association of Serum Uric Acid Levels and Various Uric Acid-Related Ratios with Insulin Resistance and Obesity: A Preliminary Study in Adolescents

BACKGROUND

Studies have shown that serum uric acid levels and uric acid-related ratios, such as uric acid-to-albumin ratio (UAR), uric acid-to-creatinine ratio (UCR), uric acid-to-high-density lipoprotein cholesterol (HDL cholesterol) ratio (UHR), and uric acid-to-lymphocyte ratio (ULR), are associated with various diseases and their complications, and that these ratios can be used as biomarkers. In the current study, we aimed to investigate uric acid levels in obese adolescents and the relationship of uric acid-related ratios with insulin resistance and obesity for the first time in the literature.

METHODS

A total of 100 adolescents (60 obese and 40 healthy) aged 10-17 years were retrospectively included. Participants were assigned to two groups: the obese group and the healthy control group. Obesity was defined as a body mass index (BMI) >the 95th percentile for age and gender. Demographic and laboratory data (serum glucose, urea, creatinine, uric acid, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), C-reactive protein (CRP), total cholesterol, triglyceride, HDL cholesterol, thyroid-stimulating hormone (TSH), free T4 (fT4), insulin levels, and complete blood count) were obtained from the laboratory information management system. A homeostatic model of assessment for insulin resistance (HOMA-IR), low-density lipoprotein cholesterol (LDL cholesterol), and uric acid-related ratios were calculated.

RESULTS

Uric acid, UAR, UCR, and UHR levels of obese adolescents were significantly higher than the healthy group (p < 0.05). We found that HOMA-IR was positively correlated with uric acid, UAR, and UHR. No correlation was found between BMI and uric acid or uric acid-related ratios. We did not find any difference between the two groups in terms of ULR levels, and we did not find any correlation between BMI and HOMA-IR.

CONCLUSION

High levels of serum uric acid, UAR, UCR, and UHR were associated with obesity. Furthermore, we found that uric acid, UAR, and UHR were positively correlated with insulin resistance.

A Systematic Review and Meta-Analysis of the Association between Uric Acid and Allantoin and Rheumatoid Arthritis

Alterations in the circulating concentrations of uric acid and its degradation product, allantoin, might account for the systemic pro-oxidant state and the increased cardiovascular risk in rheumatoid arthritis (RA). We sought to address this issue by conducting a systematic review and meta-analysis of the association between the plasma/serum concentrations of uric acid and allantoin and RA. We searched PubMed, Scopus, and Web of Science from inception to 20 June 2023 for studies comparing plasma/serum concentrations of uric acid and allantoin between RA patients and healthy controls. We assessed the risk of bias with the JBI Critical Appraisal Checklist for analytical studies and the certainty of evidence with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) Working Group system. In the 19 studies selected for analysis, there were non-significant differences in uric acid concentrations between RA patients and controls (standard mean difference, SMD = 0.11, 95% CI -0.07 to 0.30, p = 0.22; I2 = 87.9%, p < 0.001; low certainty of evidence). By contrast, the concentrations of allantoin were significantly higher in RA patients (SMD = 1.10, 95% CI 0.66 to 1.55, p < 0.001; I2 = 55.6%, p = 0.08; extremely low certainty of evidence). In meta-regression, a significant association was observed between the SMD of uric acid concentrations and body mass index, a risk factor for atherosclerosis and cardiovascular disease (t = 3.35, p = 0.007). Our study has shown a significant increase in the concentrations of the oxidative stress biomarker allantoin in patients with RA. Further research is warranted to investigate the interplay between uric acid, allantoin, redox balance, and cardiovascular disease in this group. (PROSPERO registration number: CRD42023441127).

Relationship between serum uric acid and estimated glomerular filtration rate in adolescents aged 12-19 years with different body mass indices: a cross-sectional study

Background

Globally, chronic kidney disease (CKD) is a growing public health concern. Serum uric acid (SUA) is an easily detectable and readily available biochemical indicator that has long been recognized as an independent risk factor for CKD. In addition, studies have indicated a potential relationship between SUA and body mass index (BMI). However, studies on the effect of SUA levels on the estimated glomerular filtration rate (eGFR) in adolescents with different BMIs are very rare.

Methods

Weighted multiple regression analysis was used to estimate the independent relationship between SUA and log-transformed eGFR. Additionally, we used a weighted generalized additive model and smooth curve fitting to describe the nonlinear relationships in the subgroup analysis.

Results

First, SUA was negatively associated with log-transformed eGFR even after adjusting for all covariates (β=-0.0177, 95% CI: -0.0203-0.0151, P<0.0001). Second, the results of the stratified analysis found that after adjusting for all covariates, the decrease in log-transformed eGFR due to changes in per SUA levels (Per 1, mg/dL increase) was elevated in female adolescents (β=-0.0177, 95% CI: -0.0216, -0.0138, P<0.0001), adolescents aged 12-15 years (β=-0.0163, 95% CI: -0.0200, -0.0125, P<0.0001) and black (β=-0.0199, 95% CI: -0.0251, -0.0148, P<0.0001) adolescents. Furthermore, we found that adolescents with a higher BMI had higher SUA levels, and the effect of SUA on eGFR was significantly higher in underweight adolescents (β=-0.0386, 95% CI: (-0.0550, -0.0223), P<0.0001).

Conclusion

SUA was negatively associated with the eGFR in adolescents aged 12-19 years. Furthermore, we found for the first time that SUA affects the eGFR differently in adolescents with different BMIs. This effect was particularly significant in underweight adolescents.

Association between serum uric acid and female infertility: a cross-sectional study of National Health and Nutrition Examination Survey (NHANES) 2013-2018

BACKGROUND

Female infertility is a major problem for women of reproductive-age worldwide. Oxidative stress and inflammation are involved in processes related to female infertility. Serum uric acid levels, an indicator of oxidative stress and inflammation, have rarely been reported to be associated with female infertility. This study aimed to investigate the relationship between serum uric acid levels and female infertility.

METHODS

This cross-sectional study included women aged 18-44 years from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2018. All data were extracted from NHANES questionnaires and laboratory measurements. Weighted univariable and multivariable logistic regression analyses were utilized to explore the relationship between serum uric acid and female infertility. Stratified analyses were performed based on body mass index (BMI, < 25 kg/m² and ≥ 25 kg/m²) and age (≤ 30 years and > 30 years). The odds ratio (OR) with 95% confidence interval (CI) was used to report associations.

RESULTS

A total of 2,884 women were included, of which 352 (13.30%) had infertility. Women with high serum uric acid concentrations were related to higher odds of infertility (OR = 1.20, 95%CI: 1.03-1.39) after adjusting for confounders. Compared with serum uric acid concentrations ≤ 3.72 mg/dL, women with uric acid concentrations of 4.43-5.13 mg/dL (OR = 1.65, 95%CI: 1.02-2.67) and > 5.13 mg/dL (OR = 1.86, 95%CI: 1.10-3.13) were related to higher odds of infertility. Stratified analyses showed that high serum uric acid concentrations were associated with higher odds of infertility in women with a BMI < 25 kg/m² (OR = 1.41, 95%CI: 1.04-1.93), but not in women with a BMI ≥ 25 kg/m² (P = 0.056). In addition, high serum uric acid concentrations were associated with higher odds of infertility in women aged > 30 years (OR = 1.23, 95%CI: 1.04-1.45), but not in women aged ≤ 30 years (P = 0.556).

CONCLUSION

Women with high serum uric acid concentrations were associated with higher odds of infertility, and this association may vary by BMI and age.

Elevated serum uric acid level is associated with adverse reproductive outcomes in women with polycystic ovary syndrome undergoing in vitro fertilization or intracytoplasmic sperm injection embryo transfer cycles: a retrospective cohort study

BACKGROUND

Serum uric acid levels are elevated in polycystic ovary syndrome, however, the relationship between serum uric acid level and reproductive outcomes in women with polycystic ovary syndrome remains unclear.

OBJECTIVE

This study aimed to investigate the association between serum uric acid level and the reproductive outcomes in women with polycystic ovary syndrome undergoing in vitro fertilization or intracytoplasmic sperm injection embryo transfer cycles.

STUDY DESIGN

This was a retrospective cohort study performed at a university-affiliated reproductive medicine center. A total of 1903 women with polycystic ovary syndrome undergoing their first in vitro fertilization or intracytoplasmic sperm injection embryo transfer cycles between January 2010 and January 2021 were initially included. The trends for reproductive outcomes in polycystic ovary syndrome across quartiles of serum uric acid levels were assessed. A logistic regression analysis was performed to obtain the odds ratios for in vitro fertilization outcomes based on the quartiles of serum uric acid with or without adjusting for potential confounding variables. Using generalized additive models, serum uric acid was further treated as its original continuous property to visualize its nonlinear relationship with in vitro fertilization outcomes. The live birth rate was the main outcome.

RESULTS

After exclusions, a total of 883 women with polycystic ovary syndrome with their first fresh-embryo transfer cycles were included. In quartiles of serum uric acid levels, there was a significant decreasing trend in the live birth rate from the lowest quartile (Q1: 61.8%) to the highest (Q4: 45.9%) (P_trend=.002). The percentage of low birthweight increased from Q1 (22.3%) to Q4 (31.7%) (P_trend=.049). Compared with those in Q1, women in Q4 showed a significant lower probability of live birth and clinical pregnancy and a higher risk for low birthweight (all P<.05). Both the unadjusted and adjusted generalized additive models indicated that as the serum uric acid level increased, the probability of clinical pregnancy and the live birth rate exhibited an overall decreasing profile, and the risk for low birthweight showed an increasing profile.

CONCLUSION

An elevated serum uric acid level is associated with decreased probabilities of live birth and clinical pregnancy and an increased risk for low birthweight in women with polycystic ovary syndrome. However, these associations may be confounded by other factors and more well-designed studies are needed to confirm these findings in the future.

[Clinical Characteristics of Obstructive Sleep Apnea and Comorbid Primary Aldosteronism]

Objective

To explore the characteristics of patients with obstructive sleep apnea (OSA) and comorbid primary aldosteronism (PA) and to explore the relevant factors affecting plasma aldosterone concentration.

Methods

A total of 105 patients diagnosed with PA and admitted at West China Hospital, Sichuan University between January 2016 and December 2021 were retrospectively analyzed. The subjects were divided into a PA with comorbid snoring group (n=20) and a PA with comorbid OSA group (n=85) based on the results of polysomnography (PSG). The PA with comorbid OSA group was further divided into mild, moderate, and severe subgroups according to the apnea-hypopnea index (AHI). A total of 85 outpatients diagnosed with OSA were included as the control group. Demographic, clinical, biochemical, and PSG data were compared between the groups.

Results

Compared with patients with only OSA, a significantly higher proportion of patients with OSA and comorbid PA had hypertension and elevated levels of systolic and diastolic blood pressure (P<0.05). In addition, patients with OSA and comorbid PA had significantly increased AHI and significantly decreased mean oxygen saturation and sleep efficiency (P<0.05). The more severe the OSA was, the higher levels of BMI, cholesterol, low-density lipoprotein, and uric acid the PA patients had. Linear regression analysis showed that the lowest oxygen saturation (β=－0.222, P=0.045) was negatively correlated with plasma aldosterone concentration.

Conclusion

Comorbidity with PA can aggravate the clinical manifestations of OSA, while OSA further disrupted the metabolism of lipids and uric acid in PA patients. Plasma aldosterone concentrations in patients with comorbid OSA and PA were affected by the lowest oxygen saturation level.

Relationship between bone mineral density and hyperuricemia in obesity: A cross-sectional study

BACKGROUND

Obesity is an increasingly severe global public health issue. This study aims to estimate the cross-sectional association between bone mineral density (BMD) and hyperuricemia (HU) in obesity.

METHOD

A total of 275 obese subjects (126 men and 149 women) participated in this cross-sectional study. Obesity was diagnosed as body mass index (BMI) ≥28 kg/m², whereas HU was defined as the blood uric acid level of 416 μmol/L in men and 360 μmol/L in women. The BMD of the lumbar spine and right hip was measured by dual-energy X-ray absorptiometry (DXA). The multivariable logistic regressions were employed to examine the relationship between BMD and HU in obesity, with the adjustment of gender, age, fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, creatinine, blood urea nitrogen, high-sensitivity C-reactive protein (hs-CRP), cigarette smoking, and alcohol drinking status.

RESULT

The overall prevalence of HU was 66.9% in this obese population. The mean age and BMI of this population were 27.9 ± 9.9 years and 35.2 ± 5.2 kg/m², respectively. The multivariable-adjusted OR (the highest vs. lowest BMD quartile) demonstrated a negative relationship between BMD and HU in total (OR = 0.415, 95%CI: 0.182-0.946; p = 0.036), L1 (OR = 0.305, 95%CI: 0.127-0.730; p = 0.008), L2 (OR = 0.405, 95%CI: 0.177-0.925; p = 0.032), and L3 (OR = 0.368, 95%CI: 0.159-0.851; p = 0.020) lumbar vertebrae. In the subgroup analysis for the male population, the BMD was also negatively associated with HU in total (OR = 0.077, 95%CI: 0.014-0.427; p = 0.003), L1 (OR = 0.019, 95%CI: 0.002-0.206; p = 0.001), L2 (OR = 0.161, 95%CI: 0.034-0.767; p = 0.022), L3 (OR = 0.186, 95%CI: 0.041-0.858; p = 0.031), and L4 (OR = 0.231, 95%CI: 0.056-0.948; p = 0.042) lumbar vertebrae. However, such findings did not exist in women. In addition, there was no significant relationship between hip BMD and HU in obesity.

CONCLUSION

Our results showed that the lumbar BMD was negatively associated with HU in obesity. However, such findings only existed in men, rather than women. In addition, no significant relationship between hip BMD and HU existed in obesity. Due to the limited sample size and nature of the cross-sectional design, further large prospective studies are still needed to clarify the issues.

Serum fibrinogen-like protein 1 as a novel biomarker in polycystic ovary syndrome: a case-control study

PURPOSE

To investigate the relationship between fibrinogen-like protein 1 (FGL-1) concentrations and various metabolic characteristics in patients with polycystic ovary syndrome (PCOS) and explore whether FGL-1 could be a predictive biomarker for PCOS.

METHODS

This case-control study included 136 patients with PCOS and 34 normal controls recruited in the Department of Endocrinology and Metabolism, Shanghai Tenth People's Hospital between May 2017 and June 2021. Anthropometric characteristics, metabolic parameters, and reproductive hormones were collected. Serum FGL-1 measurement was conducted using enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

Serum FGL-1 concentrations were higher in patients with PCOS than in control subjects in body mass index (BMI) subgroups, insulin resistance (IR) subgroups, and hepatic function subgroups, respectively. Serum FGL-1 concentrations were significantly associated with BMI, glycosylated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), homeostasis model assessment of insulin resistance (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), high-density lipoprotein cholesterol (HDL-c), and serum uric acid (SUA) in all individuals. The receiver operating characteristic (ROC) curve analysis revealed that the best cutoff value for FGL-1 levels to predict PCOS was 21.02 ng/ml with a sensitivity of 74.3% and a specificity of 70.6%. Both univariate and multiple logistic regressions indicated that the odds ratio (OR) for PCOS significantly increased in the subjects with high levels of FGL-1.

CONCLUSION

In our study, FGL-1 was associated with serum aminotransferase and various metabolic indexes. Moreover, the high risk of PCOS was independently associated with the increased FGL-1 levels, which suggested that FGL-1 could be a predictive biomarker for PCOS.

Correlation of uric acid with body mass index based on NHANES 2013-2018 data: A cross-sectional study

Clinical investigation of obesity-related risk factors aids in the early detection, prevention, and management of obesity. We aimed to examine the association between obesity and serum uric acid (sUA). A cross-sectional study was conducted including 18473 subjects from the National Health and Nutrition Examination Survey (NHANES). The exposure and outcome variables were sUA and body mass index (BMI), respectively. The weighted multivariate linear regression models and smooth curve fittings were conducted to assess the association between sUA and BMI. There were significantly positive correlations between sUA and BMI in both males and females (β = 1.414, 95% CI: 1.323-1.505, P < .0001, β = 1.853, 95% CI: 1.740-1.966, P < .0001, respectively). Furthermore, individuals in the higher sUA quartiles had higher BMI than those in the lowest quartile in both males and females. Subgroup analyses were stratified by race/ethnicity, results indicated the positive association of sUA with BMI in males remained in all races including Mexican American (β = 1.203, 95% CI: 0.965-1.442, P < .0001), other Hispanic (β = 1.126, 95% CI: 0.858-1.395, P < .0001), non-Hispanic White (β = 1.493, 95% CI: 1.343-1.642, P < .0001), non-Hispanic Black (β = 1.331, 95% CI: 1.122-1.540, P < .0001), and other races (β = 1.329, 95% CI: 1.115-1.544, P < .0001). And the positive association of sUA with BMI in females also remained in all races including Mexican American (β = 1.806, 95% CI: 1.520-2.092, P < .0001), other Hispanic (β = 2.033, 95% CI: 1.687-2.379, P < .0001), non-Hispanic White (β = 1.847, 95% CI: 1.657-2.037, P < .0001), non-Hispanic Black (β = 2.141, 95% CI: 1.874-2.408, P < .0001), and other races (β = 1.348, 95% CI: 1.081-1.615, P < .0001). The current cross-sectional study with 18473 US participants found that an elevated sUA was positively correlated with a higher BMI in males, females, and all kinds of races.

Correlation of obesity, dietary patterns, and blood pressure with uric acid: data from the NHANES 2017-2018

BACKGROUND

Prevalence rates of hyperuricemia and gout are increasing. Clinical investigations of hyperuricemia-related risk factors aid in the early detection, prevention, and management of hyperuricemia and gout. Ongoing research is examining the association of obesity, dietary patterns, and blood pressure (BP) with serum uric acid (sUA).

METHODS

A cross-sectional study was conducted based on the National Health and Nutrition Examination Survey. The exposures included body mass index (BMI), dietary patterns, and BP. The outcome variable was sUA level. The weighted multivariate linear regression models and smooth curve fittings were used to assess the association of BMI, dietary patterns, and BP with sUA.

RESULTS

There was a significantly positive correlation between BMI and sUA (β = 0.059, 95% CI: 0.054 to 0.064, P < 0.00001). Overweight and obese individuals had higher sUA levels than those with the normal BMI (β = 0.451, 95% CI: 0.357 to 0.546, P < 0.00001; β = 0.853, 95% CI: 0.760 to 0.946, P < 0.00001; respectively). Dietary energy intake was positively correlated with sUA (β = 0.000, 95% CI: 0.000 to 0.000, P = 0.01057). Dietary intake of carbohydrate and fiber were negatively correlated with sUA (β = - 0.001, 95% CI: - 0.002 to - 0.000, P < 0.00001; β = - 0.008, 95% CI: - 0.011 to - 0.004, P = 0.00001; respectively). Moreover, systolic BP was positively correlated with sUA (β = 0.006, 95% CI: 0.003 to 0.009, P = 0.00002). However, no statistical differences were found about the associations of dietary intake of total sugars, protein, total fat, cholesterol, and diastolic BP with sUA.

CONCLUSIONS

The current cross-sectional investigation of a nationally representative sample of US participants showed that BMI, dietary energy intake, and systolic BP were positively correlated with sUA levels; dietary carbohydrate and fiber intake were negatively correlated with sUA levels. The findings might be helpful for the management and treatment of hyperuricemia and gout.

Serum Uric Acid Levels and Cardiometabolic Profile in Middle-Aged, Treatment-Naïve Hypertensive Patients

INTRODUCTION

Uric acid (UA) is a risk factor associated with cardiometabolic diseases. However, the appropriate threshold of UA remains a matter of controversy.

AIM

To assess whether slightly increased UA levels have any significance in middle-aged, treatment-naïve persons with new-onset hypertension.

METHODS

In this cross-sectional study we recruited middle-aged participants with new-onset hypertension who were treatment-naïve. Subjects below (Group 1) and above the median UA levels (Group 2) were compared regarding clinical and laboratory characteristics that are implicated in cardiovascular and renal risk. The study population consisted of 369 persons (mean age 48.4±10 years) with median UA of 4.8 mg/dl. Group 2 individuals were predominantly male and had higher levels of blood pressure, increased body mass index, waist circumference, and a greater degree of insulin resistance. Additionally, greater lipid profile abnormalities were detected. This group also exhibited a significantly decreased fractional excretion of UA. Multivariate analysis demonstrated that serum UA levels were correlated with male sex, waist circumference, estimated glomerular filtration rate (eGFR), serum calcium and insulin levels, as well as with fractional excretion of UA. A positive association between serum UA levels and the number diagnostic criteria of the metabolic syndrome (MtS) was also noticed. After reclassification of subjects according to UA quartiles, individuals with UA levels ≥ 3.8 mg/dl had significantly higher odds (2.5-fold to 9.8-fold) of having MtS after adjustment of age, sex, and eGFR.

CONCLUSIONS

Uric acid levels in middle-aged, treatment-naïve hypertensive patients are correlated with risk factors for cardiovascular and renal disease.

Positive association between weight-adjusted-waist index and hyperuricemia in patients with hypertension: The China H-type hypertension registry study

BACKGROUND AND AIMS

The relationship between the new obesity index weight-adjusted-waist index (WWI) and hyperuricemia is unclear. We aimed to explore the association of the WWI and hyperuricemia among the hypertensive population.

METHODS

A total of 14,078 hypertension participants with complete data were included in our study. WWI was calculated by waist circumference divided by the square root of weight. Specifically, men with 420 μmol/L and women with 360 μmol/L were considered to have hyperuricemia.

RESULTS

The prevalence of hyperuricemia was 61.1% in men and 51.4% in women. On the whole, multivariate logistic regression analyses found that there was a linear positive correlation of WWI with hyperuricemia in both men (OR: 1.37; 95%CI: 1.25, 1.49) and women (OR: 1.35; 95%CI: 1.26, 1.45). Subgroup analysis found that the relationship between WWI and hyperuricemia was stable in stratified subgroups (all P-interactions >.05).

CONCLUSION

WWI showed a positive association with hyperuricemia among hypertension patients.

Positive Association between the Triglyceride-Glucose Index and Hyperuricemia in Chinese Adults with Hypertension: An Insight from the China H-Type Hypertension Registry Study

BACKGROUND

Previous studies have revealed the triglyceride-glucose (TyG) index is closely related to hyperuricemia in the general population. However, this relationship in hypertensive patients has not been reported. The aims of this study are to investigate the relationship of the TyG index and hyperuricemia in adult Chinese hypertension.

METHODS

The China H-type Hypertension Registration (an observational, noninterventional, and real-world study) was conducted from March 01, 2018, to August 31, 2018, in 16 communities in Wuyuan of China. The TyG index was calculated from fasting triglycerides (mg/dL) and fasting glucose (mg/dL)/2. Hyperuricemia was categorized by uric acid concentration ≥420 μmol/L (7 mg/dL).

RESULTS

Overall average TyG index of 13,060 adults with hypertension was 8.87; age was 63.81 years. The TyG index was positively correlated with serum uric acid by multiple linear regression analyses (β = 38.03; 95% CI: 34.55 to 41.51). Coincidentally, logistic analyses also demonstrated the TyG index had a positive correlation with hyperuricemia (OR = 2.04; 95% CI: 1.87 to 2.24). Strong linear associations of the TyG index with serum uric acid and hyperuricemia were confirmed by restricted cubic spline analysis. Compared with subjects in the lowest quartile (7.13 to 8.44) of the TyG index, subjects in the 2^nd-4^th quartiles had 1.25 (95% CI: 1.10 to 1.41), 1.63 (95% CI: 1.43 to 1.86), and 2.79 (95% CI: 2.41 to 3.24) times greater incident risk of developing hyperuricemia. The TyG index had significant correlations between male patients and hyperuricemia (OR = 2.01) by subgroup analysis.

CONCLUSION

Positive associations were found between the TyG index and serum uric acid and between the TyG index and hyperuricemia in adults with hypertension. This trial was registered at clinicaltrials.gov as ChiCTR1800017274.

Establishment of sex difference in circulating uric acid is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys

Men have higher circulating levels of uric acid than women. This sex difference is suspected to be a result of suppressive effects of estradiol on uric acid. If so, estradiol would be inversely associated with circulating uric acid. This study aimed to test this hypothesis. This cross-sectional study included 9472 participants (weighted sample size of 184,342,210) aged 12-80 years from the 2013 to 2016 US National Health and Nutrition Examination Survey. Associations of sex hormones with uric acid were analyzed using weighted least squares regression, adjusting for demographic characteristics, lifestyle risk factors, and comorbidities. Neither free nor bioavailable estradiol was inversely associated with circulating uric acid in adolescent boys or girls, or adult men or women, or perimenopausal women after full adjustment. The sex difference in uric acid was established during adolescence as a result of a dramatic increase in uric acid in adolescent boys. During adolescence, the increase in estradiol in girls over time was accompanied by a relatively unchanged level of uric acid. All three fractions of estradiol (free, bioavailable, and total) were positively associated with uric acid in adolescent boys and girls after full adjustment. In adolescent boys, all three fractions of testosterone were positively associated with serum uric acid, and sex hormone-binding globulin was inversely associated with uric acid after full adjustment. These results suggest that estradiol is not inversely associated with circulating uric acid in adolescents and the establishment of sex difference in circulating uric acid during adolescence is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys.

Purine metabolites and complex diseases: role of genes and nutrients

PURPOSE OF REVIEW

Purines have several important physiological functions as part of nucleic acids and as intracellular and extracellular signaling molecules. Purine metabolites, particularly uric acid, have been implicated in congenital and complex diseases. However, their role in complex diseases is not clear and they have both beneficial and detrimental effects on disease pathogenesis. In addition, the relationship between purines and complex diseases is affected by genetic and nutritional factors. This review presents latest findings about the relationship between purines and complex diseases and the effect of genes and nutrients on this relationship.

RECENT FINDINGS

Evidence from recent studies show strong role of purines in complex diseases. Although they are causal in only few diseases, our knowledge about their role in other diseases is still evolving. Of all the purines, uric acid is the most studied. Uric acid acts as an antioxidant as well as a prooxidant under different conditions, thus, its role in disease also varies. Other purines, adenosine and inosine have been less studied, but they have neuroprotective properties which are valuable in neurodegenerative diseases.

SUMMARY

Purines are molecules with great potential in disease pathogenesis as either metabolic markers or therapeutic targets. More studies need to be conducted to understand their relevance for complex diseases.

Correlation Between Serum Uric Acid and Body Fat Distribution in Patients With Polycystic Ovary Syndrome

OBJECTIVE

This study aims to investigate the correlation between serum uric acid levels and body fat distribution in patients with polycystic ovary syndrome (PCOS).

METHODS

Between May 2017 and March 2021, a total of 199 patients with PCOS were recruited from the Department of Endocrinology and Metabolism at the Shanghai Tenth People's Hospital. Anthropometric characteristics, metabolic parameters, and reproductive hormones were measured. Hyperuricemia was defined as serum uric acid (SUA) greater than 420 μmol/l. Dual-energy X-ray absorptiometry (DEXA) was used to measure body fat distribution.

RESULTS

The prevalence of hyperuricemia in patients with PCOS was 28.64%. PCOS patients with hyperuricemia are more obese and have a higher waist-to-hip ratio (WHR) and worse lipid metabolism than those without hyperuricemia. According to SUA quartiles, patients in the highest quartile had higher total testosterone (TT), body fat accumulation, and lower sex hormone-binding globulin (SHBG) than patients in the lowest quartile. SUA was correlated with percentage of total body fat, arm fat mass, leg fat mass, trunk fat mass, android/gynoid (A/G) ratio, and visceral adipose tissue (VAT) mass. After controlling possible confounders, logistic regression analysis found that only excessive VAT mass could significantly increase the risk of hyperuricemia in patients with PCOS.

CONCLUSION

In patients with PCOS, a high level of VAT mass, but not other fat compartments, will exacerbate the risk of hyperuricemia. Attention should be paid to the role of excessive VAT in the occurrence and development of PCOS with hyperuricemia.