Purine-rich foods, protein intake, and the prevalence of hyperuricemia: the Shanghai Men's Health Study

Blood mercury mediates the associations between fish consumption and serum uric acid levels among Chinese adults: A nationally representative study

Fish consumption can increase purine load in human body, and the enrichment of mercury in fish may affect the glomerular filtration function, both resulting in increased serum uric acid (SUA) levels. The data of blood mercury (BHg), fish consumption frequency and SUA levels of 7653 participants aged 18 years or older was from China National Human Biomonitoring (2017-2018). The associations between fish consumption frequency, ln-transformed BHg and SUA levels were explored through weighted multiple linear regressions. The mediating effect of BHg levels between fish consumption frequency and SUA levels was evaluated by mediation analysis. We found that both the fish consumption frequency and BHg were positively associated with SUA levels in both sexes. Compared to participants who had never consumed fish, participants who consumed fish once a week or more had higher SUA levels [β (95% confidence interval, CI): 20.39 (2.16, 38.62) in males; β (95% CI): 10.06 (0.76, 19.37) in females] and ln-transformed BHg [β (95% CI): 0.97 (0.61, 1.34) in males; β (95% CI): 0.84 (0.63, 1.05) in females]. Each 1-unit increase in ln-transformed BHg, the SUA levels rose by 4.78 (95% CI: 0.01, 9.54) μmol/L for males and 3.81 (95% CI: 1.60, 6.03) μmol/L for females. The association between fish consumption with SUA levels was mediated by ln-transformed BHg with the percent mediated of 34.66% in males and 26.58% in females. It revealed that BHg played mediating roles in the elevation of SUA levels caused by fish consumption. This study's findings could promote the government to intervene in mercury pollution in fish, so as to ensure the safety of fish consumption.

Effects of dietary factors on hyperuricaemia and gout: a systematic review and meta-analysis of observational studies

This study aimed to gather the best evidence on the relationship between dietary factors and hyperuricaemia and gout. We searched databases including PubMed, Embase, Cochrane, and Web of Science from database creation to July 2023. Meta-analysis showed that consumption of alcohol (OR: 1.41, 95% CI: 1.29-1.55; 1.60, 95% CI: 1.33-1.93, respectively), red meat (OR:1.27, 95% CI: 1.18-1.37; 1.32, 95% CI: 1.18-1.47, respectively), fructose (OR: 1.29, 95% CI: 1.21-1.38; 1.65, 95% CI: 1.36-2.01, respectively) and seafoods (OR: 1.40, 95% CI: 1.20-1.64; 1.29, 95% CI: 1.00-1.67, respectively) were positively associated with the risk of hyperuricaemia and gout, while vegetables (OR: 0.78, 95% CI: 0.71-0.85; 0.96,95% CI 0.74-1.24, respectively) were inversely associated. Dairy products (OR: 0.69, 95% CI: 0.61-0.78) and nuts (OR: 0.75, 95% CI: 0.60-0.93) were also inversely associated with the risk of hyperuricaemia. Soy products (OR: 0.86, 95% CI: 0.75-0.98) and coffee (OR: 0.56, 95% CI: 0.39-0.81) were negatively associated with the risk of gout.

The Effects of Diet, Dietary Supplements, Drugs and Exercise on Physical, Diagnostic Values of Urine Characteristics

Background/Objectives: This review summarizes the current knowledge about factors that affect the physical characteristics of urine. It highlights proper urine sample collection and displays factors like diet, hydration status, and medications that can alter urine color, odor, clarity, specific gravity and pH. Results: Urinalysis is a minimally invasive examination of a patient's health, especially concerning nephrological and endocrinological abnormalities, as well as dietary habits and stimulants used. Certain deviations in appearance, composition or frequency/pain during urination may indicate an ongoing disease process in the body. Based on laboratory results, further medical treatment is determined. The reason for a change in the color of the urine, for its clouding or intense odor may be a disease, as well as the consumption of food, medication, intensive physical exercise or inadequate hydration of the body. Well-standardized procedures for collecting, transporting, preparing and analyzing samples should become the basis for an effective diagnostic strategy in urinalysis. It is worth noting that pharmacists in pharmaceutical care are often the first people to whom a patient turns for health advice and for the interpretation of simple laboratory tests. Acquiring the ability to interpret the results of laboratory tests and the principles of proper sampling for laboratory tests is indispensable in the process of possible counseling and providing reliable answers to patients' questions. Conclusions: Although urinalysis is not recommended as a routine screening tool for the general population, it can prove to be a valuable source of patient health data in some cases as the data will be useful to physicians and pharmacists to more effectively diagnose and better care for patients.

Dietary polyunsaturated fatty acids intake is negatively associated with hyperuricemia: The National Health and Nutrition Examination Survey 2003-2015

BACKGROUND AND AIMS

The objective of this research was to explore the associations between dietary PUFAs intake and hyperuricemia risk.

METHODS AND RESULTS

Based on the National Health and Nutrition Examination Survey (NHANES) 2003-2015, all eligible individuals were divided into hyperuricemia and non-hyperuricemia groups based on diagnostic criteria for hyperuricemia (serum uric acid >420 μmol/L for men and >360 μmol/L for women). Multivariate-adjusted logistic regression was employed to explore the relationship between dietary PUFAs intake and hyperuricemia risk. Total PUFAs and their subtypes were modeled to isocalorically replace saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Higher intake of n-3 PUFAs, n-6 PUFAs, linoleic acid (LA), alpha-linoleic acid (ALA), and non-marine PUFAs intake correlated with decreased hyperuricemia risk, with adjusted odds ratio (OR) and 95% confidence interval (95%CIs) were 0.77 (0.63, 0.93), 0.75 (0.61, 0.92), 0.75 (0.61, 0.91), 0.69 (0.55, 0.87), and 0.73 (0.59, 0.91), respectively. Replacing 5% of total energy intake from SFAs with isocaloric PUFAs was associated with decreased odds of hyperuricemia in men (0.69 (0.57, 0.84)) and in individuals (0.81 (0.71, 0.92)). Similar trends were observed in the substitution of SFAs with non-marine PUFAs in men (0.87 (0.80, 0.94)) and in all individuals (0.92 (0.88, 0.98)). Sensitivity analyses exhibited consistent results with primary analyses.

CONCLUSION

Higher dietary intake of n-3 PUFAs, n-6 PUFAs, LA, ALA, and non-marine PUFAs was associated with decreased hyperuricemia risk. These results support the recommendation to substitute SFAs with PUFAs in diet.

Association between exposure to a mixture of organochlorine pesticides and hyperuricemia in U.S. adults: A comparison of four statistical models

The association between the exposure of organochlorine pesticides (OCPs) and serum uric acid (UA) levels remained uncertain. In this study, to investigate the combined effects of OCP mixtures on hyperuricemia, we analyzed serum OCPs and UA levels in adults from the National Health and Nutrition Examination Survey (2005-2016). Four statistical models including weighted logistic regression, weighted quantile sum (WQS), quantile g-computation (QGC), and bayesian kernel machine regression (BKMR) were used to assess the relationship between mixed chemical exposures and hyperuricemia. Subgroup analyses were conducted to explore potential modifiers. Among 6,529 participants, the prevalence of hyperuricemia was 21.15%. Logistic regression revealed a significant association between both hexachlorobenzene (HCB) and trans-nonachlor and hyperuricemia in the fifth quintile (OR: 1.54, 95% CI: 1.08-2.19; OR: 1.58, 95% CI: 1.05-2.39, respectively), utilizing the first quintile as a reference. WQS and QGC analyses showed significant overall effects of OCPs on hyperuricemia, with an OR of 1.25 (95% CI: 1.09-1.44) and 1.20 (95% CI: 1.06-1.37), respectively. BKMR indicated a positive trend between mixed OCPs and hyperuricemia, with HCB having the largest weight in all three mixture analyses. Subgroup analyses revealed that females, individuals aged 50 years and above, and those with a low income were more vulnerable to mixed OCP exposure. These results highlight the urgent need to protect vulnerable populations from OCPs and to properly evaluate the health effects of multiple exposures on hyperuricemia using mutual validation approaches.

Effects of Low Temperature-Ultrasound-Papain (LTUP) Combined Treatments on Purine Removal from Pork Loin and Its Influence on Meat Quality and Nutritional Value

A combined pretreatment method of "low temperature-ultrasound-papain" (LTUP) was proposed to remove the purine of pork loins. Compared with untreated pork loin, under optimal conditions (temperature 58 °C, ultrasound density 100 W/cm2, and papain concentration 0.085%), the purine removal rate of treated pork loin could reach 59.29 ± 1.39%. The meat quality of pork loin treated with the LTUP method such as hardness and chewiness decreased by 58.37% and 64.38%, respectively, and the in vitro protein digestibility was increased by 19.64%; the cooking loss was decreased by 15.45%, compared with the simulated household blanching process (HT). In view of the high purine removal rate, the losses of free amino acids and soluble peptides were acceptable and reasonable. SEM and LF-NMR results showed that low temperature and ultrasound combined with papain treatment opened a channel for purine transfer and promoted purine dissolution by affecting the protein structure of pork loin. In addition, the migration of water within the muscle tissue was also related to purine removal. In summary, LTUP is recommended as an efficient and green way for the meat industry to remove purine.

Understanding Hyperuricemia: Pathogenesis, Potential Therapeutic Role of Bioactive Peptides, and Assessing Bioactive Peptide Advantages and Challenges

Hyperuricemia is a medical condition characterized by an elevated level of serum uric acid, closely associated with other metabolic disorders, and its global incidence rate is increasing. Increased synthesis or decreased excretion of uric acid can lead to hyperuricemia. Protein peptides from various food sources have demonstrated potential in treating hyperuricemia, including marine organisms, ovalbumin, milk, nuts, rice, legumes, mushrooms, and protein-rich processing by-products. Through in vitro experiments and the establishment of cell or animal models, it has been proven that these peptides exhibit anti-hyperuricemia biological activities by inhibiting xanthine oxidase activity, downregulating key enzymes in purine metabolism, regulating the expression level of uric acid transporters, and restoring the composition of the intestinal flora. Protein peptides derived from food offer advantages such as a wide range of sources, significant therapeutic benefits, and minimal adverse effects. However, they also face challenges in terms of commercialization. The findings of this review contribute to a better understanding of hyperuricemia and peptides with hyperuricemia-alleviating activity. Furthermore, they provide a theoretical reference for developing new functional foods suitable for individuals with hyperuricemia.

Single-nucleotide polymorphisms link gout with health-related lifestyle factors in Korean cohorts

Gout-a very painful inflammatory arthritis caused by the deposition of monosodium urate crystals in the joints-is influenced by several factors. We identified the association of single- nucleotide polymorphisms (SNPs) that link gout with health-related lifestyle factors using genomic data from the Korean Genome and Epidemiology Study. We conducted a genome-wide association study (GWAS) on 18,927 samples of 438 Korean patients with gout and 18,489 controls for the discovery stage. For the replication stage, another batch containing samples of 326 patients with gout and 2,737 controls were analyzed. Lastly, a meta-analysis was performed using these two cohorts. We analyzed the effects of health-related lifestyle factors, including eating habits, physical activity, drinking behavior, and smoking behavior, on gout. After identifying the association between GWAS-derived SNPs and health-related lifestyle factors, we confirmed the interaction between the polygenic risk score (PRS) and health-related lifestyle factors. We identified 15 SNPs related to gout, among which rs1481012 of ABCG2 located on chromosome 4 has been newly discovered (P = 2.46e-11). On examining the interaction between SNPs and health-related lifestyles, rs3109823-located in ABCG2-was found to be associated with smoking status. In addition, rs11936395-located in SLC2A9-was significantly associated with the average momentum of exercise per session, whereas rs11066325 located in PTPN11, showed a significant association with the number of exercise sessions per week, smoking status, drinking status, and amount of soju drink per session. rs9421589-located in FAM35A-was significantly associated with the duration of smoking. In addition, we verified that the association between PRS and duration of smoking affects gout. Thus, in this study, we identified novel SNPs that link gout with health-related lifestyle factors in the Korean population.

Insights into the molecular mechanism of dextran sulfate inhibiting DNA digestion by pepsin: a crucial role of sulfate group on the binding to DNA

Sulfate polysaccharides can inhibit DNA digestion in simulated gastric juice in vitro, which is important for regulating dietary nucleic acids metabolism, but the mechanism of inhibition is unclear. This study used dextran sulfate (DS) with different sulfate groups and molecular weights to explore the effect of DS on DNA digestion. Molecular interactions between DS and DNA were investigated by biolayer interferometry (BLI), isothermal titration calorimetry (ITC) and molecular dynamics simulations. Results indicated that DS with higher molecular weight and sulfate group content showed stronger inhibitory effect of DNA digestion. ITC results showed that the combined Kd value of DNA and DS was about 2.53 mM. The main reason for inhibition of DNA digestion is that the formation of hydrogen bonds between the sulfate group of DS and DNA bases hinders the binding of DNA to pepsin. This finding will facilitate new strategies for nucleic acid metabolism and oral drug delivery.Communicated by Ramaswamy H. Sarma.

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).

Clinical significance of hypouricemia in children and adolescents

BACKGROUND

Although hyperuricemia is a widely studied condition with well-known effects on the kidneys, hypouricemia is usually considered a biochemical abnormality of no clinical significance despite the fact that it can be a sign or major finding of serious metabolic or genetic diseases affecting kidney health. In this study, we aimed to investigate and emphasize the clinical significance of hypouricemia.

METHODS

Patients were evaluated retrospectively for persistent hypouricemia defined as serum uric acid concentrations of < 2 mg/dL on at least 3 different occasions. According to the blood and urine uric acid (UA) levels, the patients were classified as having hypouricemia due to UA underproduction vs. overexcretion. Demographic, clinical, and genetic characteristics were noted for analysis.

RESULTS

Fourteen patients (n = 14; M/F 8/6) with persistent hypouricemia were identified. Hypouricemia due to underproduction was the cause of 42.8% of these cases. All of the patients with a uric acid level of 0 mg/dL (n = 4) had hypouricemia due to underproduction. The median serum uric acid level was 0.85 (0-1.6) mg/dL. Isolated hypouricemia and hypouricemia with metabolic acidosis were equally distributed. Among the patients with hypouricemia due to underproduction, the final diagnoses were xanthine dehydrogenase deficiency (n = 5) and alkaptonuria (n = 1). In the overexcretion group, the final diagnoses were nephropathic cystinosis (n = 6), distal renal tubular acidosis (n = 1), and hereditary renal hypouricemia (n = 1). The diagnostic lag was longer for patients with isolated hypouricemia compared to other patients (p = 0.001).

CONCLUSIONS

Hypouricemia may reflect underlying genetic or metabolic diseases, early diagnosis of which could help preserve kidney function. A higher resolution version of the Graphical abstract is available as Supplementary information.

Elevated Serum Uric Acid Is Associated With Gestational Diabetes Mellitus: An Observational Cohort Study

CONTEXT

Elevated serum uric acid may be closely related to the occurrence of gestational diabetes mellitus (GDM).

OBJECTIVE

We aimed to elucidate the relationship between changes in serum uric acid before 24 weeks of gestation and the risk of GDM and associated adverse pregnancy outcomes and provide clinical epidemiological evidence for the involvement of uric acid in the etiology of GDM.

METHODS

We conducted a retrospective cohort study of 23 843 singleton pregnant women between February 2018 and June 2022. The exposure factor was serum uric acid before 24 weeks of gestation, primary outcome was gestational diabetes diagnosed at 24 to 28 weeks of gestation, and secondary outcomes were GDM A2 (GDM requiring pharmacotherapy), GDM combined with pre-eclampsia, preterm delivery, and large for gestational age infants. Adjusted risk ratios (RRs) were calculated using multivariate predictive marginal proportions from logistic regression models.

RESULTS

Among 23 843 singleton pregnant women, 3204 (13.44%) were diagnosed with GDM at 24 to 28 weeks of gestation, and elevated uric acid before 24 weeks of gestation was strongly associated with the risk of GDM. Compared with uric acid <240 µmol/L, the RR for GDM was 1.43 (95% CI 1.29-1.56) when uric acid was between 240 and 300 µmol/L; when uric acid was >300 µmol/L, the RR for GDM was 1.82 (95% CI 1.55-2.15). In secondary outcomes uric acid had a similar relationship with GDM A2, preterm birth, and GDM combined with pre-eclampsia.

CONCLUSION

Elevated uric acid levels before 24 weeks of gestation are associated with subsequent GDM; the best time to test for uric acid is before 18 weeks of gestation. Pregnant women with low and intermediate risk for GDM development may benefit more from serum uric acid measurements before 18 weeks of gestation.

n-3 PUFA poor seafood consumption is associated with higher risk of gout, whereas n-3 PUFA rich seafood is not: NHANES 2007–2016

Background and aims

Gout, the most prevalent inflammatory arthritis, has undesirable effects on the quality of life. Omega-3 polyunsaturated fatty acids (n-3 PUFA) has a strong link with anti-inflammatory impacts. However, whether the harmful effects of seafood in relation to gout may vary owing to different levels of n-3 PUFA in seafood is still unclear. It was the goal of this study to examine the relationship between n-3 PUFA poor/rich seafood consumption and gout.

Methods

Between 2007 and 2016, five NHANES cycles were performed, with 12,505 subjects having complete data for gout and two 24-h dietary intake interviews. The 24-h dietary recalls were utilized to evaluate dietary habits. Gout was defined based on questionnaires. Weighted logistic regression models were conducted to investigate the association between n-3 PUFA poor/rich seafood consumption and gout. Moreover, subgroup analysis was utilized to estimate the stability of results. Covariates including age, gender, race/ethnicity, income, education, body mass index, chronic kidney disease, diabetes mellitus, hypertension, smoking status, and drinking status were stratified in different models.

Results

In the fully adjusted model, each unit of increase of n-3 PUFA poor seafood intake was associated with an 8.7% increased risk of gout (OR = 1.087, 95% CI: 1.039, 1.138, P &lt; 0.001), whereas, no correlation was found between n-3 PUFA rich seafood consumption and gout. It also provided a proof-of-concept regarding the potential for n-3 PUFA rich seafood to counteract harmful effects of purines in relation to gout. A dose-response analysis showed that there was a non-linear relationship between n-3 PUFA rich seafood intake and the risk of gout in the female group.

Conclusion

Findings suggest that n-3 PUFA poor seafood consumption is associated with higher risk of gout, whereas n-3 PUFA rich seafood is not.

Virtual screening and activity evaluation of human uric acid transporter 1 (hURAT1) inhibitors

Hyperuricemia is a disease caused by disorder of purine metabolism, mainly due to insufficient renal excretion of uric acid. Urate transporter 1 (URAT1) is the most widely studied target of urate transporters, and used for uric acid (UA) reabsorption. This study used the AlphaFold2 algorithm to predict the structure of URAT1. Virtual screening and biological evaluation were used to discover novel URAT1 inhibitors that target the critical amino acids. Seven compounds were screened from the T2220 database and validated as URAT1 inhibitors by cell biology experiments. The IC50 values of benbromarone, NP023335, TN1148, and TN1008 were 6.878, 18.46, 24.64, and 53.04 μM, respectively. Molecular dynamics simulation was used to investigate the binding mechanism of URAT1 to NP023335, which forms stable contact with Ser35, Phe365, and Arg477. These interactions are essential for maintaining the biological activity of NP023335. The three compounds' pharmacokinetic characteristics were predicted, and NP023335's properties matched those of an empirical medication with the benefits of high solubility, low cardiotoxicity, good membrane permeability, and oral absorption. The natural product NP023335 will serve as a promising hit compound for facilitating the further design of novel URAT1 inhibitors.

[2022 Update of the Austrian Society for Rheumatology and Rehabilitation nutrition and lifestyle recommendations for patients with gout and hyperuricemia]

BACKGROUND

Gout is the most frequent inflammatory joint disease in the western world and has a proven genetic background. Additionally, lifestyle factors, such as increasing life expectation and standard of living, sufficient or excess nutrition and a growing prevalence of obesity in the population as well as e.g. alcohol consumption, contribute to the rising incidence of hyperuricemia and gout. Apart from an adequate medication, medical consultation on nutrition and lifestyle is an essential part of the management of gout patients, who have a high risk of internal comorbidities.

OBJECTIVE

In 2015 the Austrian Society for Rheumatology and Rehabilitation (ÖGR) working group for osteoarthritis and crystal arthropathies published nutrition and lifestyle recommendations for patients with gout and hyperuricemia. Since then, a multitude of studies have been published addressing this topic, which necessitated an update.

METHODS

First, the authors performed a hierarchical literature search to screen for the literature published since 2015. Considering references given in the first publication, the relevant literature was selected and the recommendations from 2015 were either kept as published, reformulated or recreated. Finally, the evidence level and the level of agreement for each recommendation were added by the authors.

RESULTS

Based on this process, 10 recommendations were generated instead of the initial 9. As in the original publication, a graphical presentation with symbols was constructed to complement the written text.

CONCLUSION

The ÖGR recommendations on nutrition and lifestyle for patients with gout and hyperuricemia were updated in accordance with the most recent relevant literature. These are supposed to serve as information and education material for patients and updated information for physicians.

Environmental Triggers of Hyperuricemia and Gout

Gout is the most prevalent type of inflammatory arthritis worldwide and environmental factors contribute to hyperuricemia and risk for gout flare. Causes of hyperuricemia include increased purine consumption from meat, alcohol, and high fructose corn syrup as well as medications such as cyclosporine, low-dose aspirin, or diuretics. Triggers for gout flares include increased purine consumption and medication use such as urate lowering therapy and diuretics. Environmental exposures including lead exposure, particulate matter exposure, temperature fluctuations, and physiologic stress have been found to trigger flares. In the right clinical scenario, these factors should be considered when treating gout patients.

The Prevalence of Hyperuricemia and Its Correlates among Adults in China: Results from CNHS 2015-2017

This study aimed to investigate the prevalence of hyperuricemia (HUA) and associated risk factors in Chinese adults aged 18 to 59 years. All the data were collected from the China Nutrition and Health Surveillance during the period 2015–2017, which adopted a stratified, multistage, random sampling method on a national scale. A total of 52,627 participants aged 18 years or older were included in this study. The definition of hyperuricemia was 420 μmol/L for male and 360 μmol/L for female. The Rao–Scott chi-square test was used to compare the differences in prevalence between or among the subgroups. A weighted two-level multivariate survey-logistic regression was used to detect the correlations between HUA and demographic, physical, lifestyle and metabolic factors. The total prevalence of HUA was 15.1%, and that was higher in male, current smokers, higher BMI and less physical activities subgroups, and also in noninfectious chronic diseases (NCDs) subgroups. The subgroups of non-vegetarian diet, insufficient vegetable intakes and excessive red meat and alcohol intakes had significantly higher HUA prevalence. After introducing all the variables in the survey-logistic regression, gender, age, BMI, physically active, hypertension, diabetes mellitus, bean and nut intake, vegetable intake, red meat intake, alcohol consumption and vegetarian were associated with HUA. Among the significant variables, age and physical active served as a protective factor, and BMI showed to be a risk factor for HUA. Hypertension and dyslipidemia could increase the risk for HUA, while diabetes mellitus was shown a negative association with it. For dietary factors, vegetarian diet, sufficient beans and nuts and vegetables intake could lower the risk of HUA, but more alcohol could increase the risk of HUA. Dietary factor played a key role in HUA. It suggested that the intervention of dietary factor should receive more attention to ameliorate the high prevalence of HUA in China.

Research Progress on the Relationship between Dietary Patterns and Hyperuricemia

As the final metabolite of purine metabolism, uric acid is critically associated with human health. The serum uric acid level is regulated by diet and the metabolic capacity of the human body. The impaired control of uric acid metabolism and excretion is associated with the increased level of serum uric acid, which ultimately results in hyperuricemia. Hyperuricemia is the "fourth-highest" after hypertension, hyperglycemia, and hyperlipidemia. With progress made in the relationship between diet and hyperuricemia, different dietary patterns and lifestyles have been discussed, such as exercise, the amount intake of meat, seafood, supplements with omega-3 fatty acids, sugar-sweetened soft drinks and energy drinks, and lower-fat-containing foods as well as drinking beer, wine, and spirits in the present article. This study demonstrated that a lower risk of hyperuricemia is substantially correlated with higher baseline adherence to MeDiet, and plant polyphenols can combat hyperuricemia by blocking xanthine oxidase.

Soy consumption and serum uric acid levels: A systematic review and meta-analysis

Background

Soy consumption has health benefits, but the relationship between soy and uric acid remains uncertain. This meta-analysis and systematic review evaluated the effects of soy intake on plasma uric acid.

Methods

PubMed, Embase, CNKI, and the Cochrane Library were searched for studies evaluating the effects of soy, soy products, soy protein, and soy isoflavones on uric acid levels. The primary outcome was serum or plasma uric acid concentration. Study quality was evaluated by the Cochrane Collaboration and SYRCLE risk-of-bias tools.

Results

A total of 17 studies were included. Qualitative analysis of three human clinical studies of acute effects revealed that soy consumption increased serum uric acid concentration; however, soy-derived products, including tofu, bean curd cake, and dried bean curd sticks, had no significant effect on serum uric acid. A meta-analysis of five long-term human studies (10 data sets) revealed that soy protein and soy isoflavones had no significant effects on uric acid levels [weighted mean difference (WMD) = -2.11; 95% confidence interval (CI): -8.78, 4.55; p = 0.53]. However, most epidemiological data revealed that soy intake is inversely associated with uric acid levels. Meta-analysis of nine animal trials (29 data sets) revealed that soy protein and soy isoflavones significantly reduced serum uric acid concentrations (vs. controls; MD = -38.02; 95% CI: -50.60, -25.44; p < 0.001).

Conclusion

Soy and its products have different effects on serum uric acid. Soy products like tofu, bean curd cake, and dried bean curd sticks could be high-quality protein sources for individuals with hyperuricemia or gout. It can be beneficial to nutritionists and healthcare decision-makers reconsider their conceptions about the relationship between soy and uric acid levels according to the latest and further scientific study results.

Systematic review registration

[www.crd.york.ac.uk/PROSPERO], identifier [CRD42022331855].

Association between mixed dioxin exposure and hyperuricemia in U.S. adults: A comparison of three statistical models

BACKGROUND

Previous studies on the relationship between dioxin exposures and hyperuricemia have usually been based on multi-chemical linear models. However, the complex nonlinear relationship and interaction between mixed dioxin exposures and hyperuricemia have seldom been studied. In this study, we applied three different statistical models to assess the joint effect of 12 dioxins on hyperuricemia.

METHODS

A total of 7 dioxin-like polychlorinated biphenyls (DL-PCBs), 3 polychlorinated dibenzo-p-dioxins (PCDDs), and 2 polychlorinated dibenzofurans (PCDFs) were measured in the serum of adults by the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2004. We fitted multivariable logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models to estimate the association of individual and mixed dioxin exposures with hyperuricemia.

RESULTS

Among the 1008 individuals included in our analysis, 20.04% had hyperuricemia. In the multivariable logistic regression established for each single dioxin, PCB28, PCB74, PCB105, PCB118, and 1,2,3,4,6,7,8-HPCDD were positively associated with hyperuricemia. With including all dioxins in the multivariable logistic regression model simultaneously, only PCB28 and 1,2,3,4,6,7,8-HPCDD were positively associated with hyperuricemia. In the WQS regression model, the WQS index was significantly associated (OR (95% CI): 2.32 (1.26, 4.28)) with hyperuricemia, and 1,2,3,4,6,7,8-HPCDD (weighted 0.22) had the largest contribution. In BKMR analysis, a significant positive association was found between mixed dioxin exposure and hyperuricemia when all dioxins were at their 60th percentile or above, compared to their 50th percentile. The univariate exposure-response function showed that PCB105 and PCB118 were positively associated with hyperuricemia.

CONCLUSION

By comparing the three statistical models, we concluded that the whole-body burden of 12 dioxins was significantly positively associated with hyperuricemia. PCB105, PCB118, and 1,2,3,4,6,7,8-HPCDD played the most important roles in hyperuricemia.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

2022 update of the Austrian Society of Rheumatology and Rehabilitation nutrition and lifestyle recommendations for patients with gout and hyperuricemia

Background

Gout is the most frequent inflammatory joint disease in the western world and has a proven genetic background. Additionally, lifestyle factors like increasing life span and wealth, sufficient to excess nutritional status and a growing prevalence of obesity in the population, as well as e.g. alcohol consumption contribute to the rising incidence of hyperuricemia and gout. Apart from an adequate medication, medical advice on nutrition and lifestyle is an essential part of the management of gout patients, being at high risk of internal comorbidities.

Objective

In 2015, the ÖGR (Österreichische Gesellschaft für Rheumatologie und Rehabilitation) working group for osteoarthritis and crystal arthropathies already published nutrition and lifestyle recommendations for patients with gout and hyperuricemia. Since then, a multitude of literature has been published addressing this topic, what required an update.

Methods

First, the authors performed a hierarchical literature search to screen the meanwhile published literature. Also considering references of the first publication, the relevant literature was selected, and the 2015 recommendations were either kept as published, reformulated or newly produced. Finally, the evidence level and the level of agreement with each recommendation were added.

Results

Following this process, ten recommendations were generated instead of the initial nine. Like in the original publication, a colored icon presentation was provided to complement the written text.

Conclusion

The Austrian nutrition and lifestyle recommendations for patients with gout and hyperuricemia were updated incorporating the most recent relevant literature, serving as education material for patients and updated information for physicians.

Determination of total purine and free purine content in milk, soymilk, and enteral nutritional supplements to assist nutritional therapy for hyperuricemia and gout

In this study, we determined the purine contents in milk and soymilk, as protein-rich drinks, and in enteral nutritional supplements employed to ameliorate protein malnutrition in the elderly. Milk consumption is known to lower serum uric acid levels and to promote uric acid excretion. However, discrepant results have been reported regarding the effect of soymilk on serum uric acid levels. The purpose of this study was to quantify and compare the total purine contents and the contents of individual purines and pyrimidines by molecular type (nucleotides, nucleosides, and bases).

Gout associated with reduced renal excretion of uric acid. Renal tubular disorder that nephrologists do not treat

Gout is recurrent inflammatory arthritis caused by the deposition of monosodium urate crystals in the joints. The risk factors that predispose to suffering from gout include non-modifiable factors such as gender, age, ethnicity and genetics, and modifiable factors such as diet and lifestyle. It has been shown that the heritability of uric acid levels in the blood is greater than 30%, which indicates that genetics play a key role in these levels. Hyperuricaemia is often a consequence of reduced renal urate excretion since more than 70% is excreted by the kidneys, mainly through the proximal tubule. The mechanisms that explain that hyperuricaemia associated with reduced renal urate excretion is, to a large extent, a proximal renal tubular disorder, have begun to be understood following the identification of two genes that encode the URAT1 and GLUT9 transporters. When they are carriers of loss-of-function mutations, they explain the two known variants of renal tubular hypouricaemia. Some polymorphisms in these genes may have an opposite gain-of-function effect, with a consequent increase in urate reabsorption. Conversely, loss-of-function polymorphisms in other genes that encode transporters involved in urate excretion (ABCG2, ABCC4) can lead to hyperuricaemia. Genome-wide association study (GWAS) methods have made it possible to locate new gout-related loci associated with reduced renal urate excretion (NIPAL1, FAM35A).

Prevalence of hyperuricemia and the relationship between serum uric acid concentrations and lipid parameters among King Abdulaziz University Hospital patients

Background

Several studies have associated uric acid with dyslipidemia. However, no previous studies have examined patients without chronic illness.

Aim

: The aim of this study is to assess the relationship between serum uric acid concentration and lipid profile parameters and to estimate the prevalence of hyperuricemia in the city of Jeddah.

Patients and Methods

A retrospective study was conducted on 1206 patients who undergone laboratory blood testing over a 3-year period (2018-2020) at King Abdulaziz University Hospital, which was ethically approved. We used a predesigned checklist to collect data from electronic hospital records using Google Forms. Bivariate analysis, tables, and graphs were used to represent and identify the relationships between variables. A P value of <0.05 was considered significant.

Results

Our study revealed a prevalence of 12% for hyperuricemia in the study population. Males were more frequently affected than females (8.13% vs. 3.73%, respectively). There was no association between serum uric acid concentration and lipid profile parameters, including total cholesterol (P = 0.92), triglyceride (P = 0.42), high-density lipoprotein (P = 0.47), and low-density lipoprotein (P = 0.66). There was a strong association between serum uric acid concentration and high body mass index (P < 0.001), older age (P = 0.002), male sex (P < 0.001), and nationality (P < 0.001). Furthermore, there was an association between sex and mean erythrocyte sedimentation rate (P = 0.02) and mean triglyceride concentration (P = 0.02).

Conclusion

We observed a low prevalence of hyperuricemia, and our results indicate no association between serum uric acid concentration and lipid profile parameters.

The Association between Dietary Purine Intake and Mortality: Evidence from the CHNS Cohort Study

Objectives: To investigate the association between dietary purine intake and mortality among Chinese adults. Methods: Based on data from the 2004−2015 China Health and Nutrition Survey (CHNS) and the corresponding edition of China Food Composition, the average purine intake per day (mg/day) from 2004 to 2011 was calculated, and the surveyed population was divided into five groups by quintiles. The outcome event and timepoint of concern were defined as death and time, respectively, as reported by family members, recorded until the 2015 survey. Cox proportional hazards regression was used to estimate the hazard ratios (HRs) with 95% confidence intervals (CIs) for death. The possibly nonlinear relationship between purine intake and mortality was examined with restricted cubic splines. Results: We included 17,755 subjects, and the average purine intake among them was 355.07 ± 145.32 mg/day. Purine intake was inversely associated with mortality (Ptrend < 0.001). Compared with the lowest quintiles of purine intake, the highest quintiles (HR = 0.60; 95% CI: 0.46, 0.77) showed a significant association with lower mortality. The negative association with mortality was mainly found in plant-derived purine (Ptrend = 0.001) and, weakly, in animal-derived purine (Ptrend = 0.052). In addition, a U-shaped relationship between purine intake and mortality was observed in males; however, there was no statistically significant dose−response relationship in females. Conclusion: Considering the low-purine-intake levels of the Chinese population, we observed a U-shaped relationship between purine intake and mortality in males, but purine intake may not relate to mortality in females. Future studies should investigate the causal relationship between purine intake and disease burden in China.

Anti-Hyperuricemic Effect of Ethyl Acetate Sub-Fractions from Chrysanthemum morifolium Ramat. Dried Flowers on Potassium Oxonate-Induced Hyperuricemic Rats

Xanthine oxidase (XO) plays an important role in purine degradation in humans. The study aimed to determine the XO inhibitory potential of Chrysanthemum morifolium dried flower ethyl acetate sub-fractions and its anti-hyperuricemic effect in rat models. Bioassay-guided fractionation based on XO inhibitory assay was employed to obtain bioactive fractions and sub-fractions. In vitro cytotoxicity and cellular antioxidant capacity of the sub-fraction and its mode of XO inhibition were also investigated. The anti-hyperuricemic effect of the bioactive sub-fraction was investigated using rat models via oral consumption, and followed by an XO mRNA gene expression study. The compounds in the bioactive sub-fractions were identified putatively using HPLC-Q-TOF-MS/MS. Ethyl acetate (EtOAc) fraction exhibited the highest XO inhibition among the fractions. It was further fractionated into 15 sub-fractions. F10 exhibited high XO inhibitory activity, cellular pro-proliferative effect, and intracellular antioxidant activity among the sub-fractions tested. This sub-fraction was non-cytotoxic at 0.1–10 µg/mL, and very effective in lowering serum and urine uric acid level in rat models upon oral consumption. A total of 26 known compounds were identified and seven unknown compounds were detected via HPLC-Q-TOF–MS/MS analysis. The possible mechanisms contributing to the anti-hyperuricemic effect were suggested to be the non-competitive inhibition of XO enzyme, XO gene expression down-regulation, and the enhancement of uric acid excretion.

The chemistry, processing, and preclinical anti-hyperuricemia potential of tea: a comprehensive review

Hyperuricemia is an abnormal purine metabolic disease that occurs when there is an excess of uric acid in the blood, associated with cardiovascular diseases, hypertension, gout, and renal disease. Dietary intervention is one of the most promising strategies for preventing hyperuricemia and controlling uric acid concentrations. Tea (Camellia sinensis) is known as one of the most common beverages and the source of dietary polyphenols. However, the effect of tea on hyperuricemia is unclear. Recent evidence shows that a lower risk of hyperuricemia is associated with tea intake. To better understand the anti-hyperuricemia effect of tea, this review first briefly describes the pathogenesis of hyperuricemia and the processing techniques of different types of tea. Next, the epidemiological and experimental studies of tea and its bioactive compounds on hyperuricemia in recent years were reviewed. Particular attention was paid to the anti-hyperuricemia mechanisms targeting the hepatic uric acid synthase, renal uric acid transporters, and intestinal microbiota. Additionally, the desirable intake of tea for preventing hyperuricemia is provided. Understanding the anti-hyperuricemia effect and mechanisms of tea can better utilize it as a preventive dietary strategy.HighlightsHigh purine diet, excessive alcohol/fructose consumption, and less exercise/sleep are the induction factors of hyperuricemia.Tea and tea compounds showed alleviated effects for hyperuricemia, especially polyphenols.Tea (containing caffeine or not) is not associated with a higher risk of hyperuricemia.Xanthine oxidase inhibition (reduce uric acid production), Nrf2 activation, and urate transporters regulation (increase uric acid excretion) are the potential molecular targets of anti-hyperuricemic effect of tea.About 5 g tea intake per day may be beneficial for hyperuricemia prevention.

Gut Microbiome and Metabolome Variations in Self-Identified Muscle Builders Who Report Using Protein Supplements

Muscle builders frequently consume protein supplements, but little is known about their effect on the gut microbiota. This study compared the gut microbiome and metabolome of self-identified muscle builders who did or did not report consuming a protein supplement. Twenty-two participants (14 males and 8 females) consumed a protein supplement (PS), and seventeen participants (12 males and 5 females) did not (No PS). Participants provided a fecal sample and completed a 24-h food recall (ASA24). The PS group consumed significantly more protein (118 ± 12 g No PS vs. 169 ± 18 g PS, p = 0.02). Fecal metabolome and microbiome were analyzed by using untargeted metabolomics and 16S rRNA gene sequencing, respectively. Metabolomic analysis identified distinct metabolic profiles driven by allantoin (VIP score = 2.85, PS 2.3-fold higher), a catabolic product of uric acid. High-protein diets contain large quantities of purines, which gut microbes degrade to uric acid and then allantoin. The bacteria order Lactobacillales was higher in the PS group (22.6 ± 49 No PS vs. 136.5 ± 38.1, PS (p = 0.007)), and this bacteria family facilitates purine absorption and uric acid decomposition. Bacterial genes associated with nucleotide metabolism pathways (p < 0.001) were more highly expressed in the No PS group. Both fecal metagenomic and metabolomic analyses revealed that the PS group’s higher protein intake impacted nitrogen metabolism, specifically altering nucleotide degradation.

Remedial Action of Yoghurt Enriched with Watermelon Seed Milk on Renal Injured Hyperuricemic Rats

The consumption of plant-based dairy alternatives has increased rapidly around the world as a result of numerous positive health effects. Little information is available about the potential use of watermelon seed milk in the manufacture of yoghurt. The present study was undertaken to investigate the remedial action of yoghurt enriched with watermelon seed milk in renal injured hyperuricemic rats. A new yoghurt, substituting cow’s milk with different proportions of watermelon seed milk was prepared, followed by evaluation of its acceptability and functionality. Four different types of yoghurt were prepared from cow’s milk containing 3% fat, with different proportions of blended watermelon seed milk (0.0, 25, 50 and 75%). Sensorial traits, i.e., appearance, flavor, body and texture, and overall acceptability demonstrated that the blended treatment (50% cow’s milk and 50% watermelon seed milk.) was the most acceptable. This blend was then tested as an anti-hyperuricemia agent in rats. In this respect, twenty-four male albino rats were assigned into four groups (n = 6). The first group was solely administered a standard diet, and served as the negative control. The other rats (n = 18) received a basal diet including 20 g/kg dietary potassium oxonate in order to induce hyperuricemia. The hyperuricemic rats were then divided into three groups; the first group did not receive any treatment and served as the positive control, while the second and third groups were administered 10% cow’s milk yoghurt and 10% watermelon seed milk yoghurt, respectively. Interestingly, the results showed that the hyperuricemic group receiving a diet supplemented with 10% watermelon seed milk yoghurt was not significantly different from the negative control in the measured biological parameters, and saw a significant improvement in renal function compared to the positive control. The biologically favorable action of watermelon seed milk yoghurt could be attributed to its potential promotion of antioxidant status via enhancement of the activities of superoxide dismutase, catalase, and glutathione transferase. Collectively, this study concluded that watermelon seed milk can be used in yoghurt manufacturing in proportions of up to 50%, and may improve kidney function as an anti-hyperuricemic agent.

Dietary Acid Load Is Positively Associated with the Incidence of Hyperuricemia in Middle-Aged and Older Korean Adults: Findings from the Korean Genome and Epidemiology Study

Hyperuricemia has been associated with a number of chronic diseases, such as type 2 diabetes mellitus, hypertension, and cardiovascular diseases. Dietary acid load plays a key role in regulating uric acid levels. We hypothesized that potential renal acid load (PRAL) and net endogenous acid production (NEAP) score would be positively associated with the incidence of hyperuricemia. Data from the Health Examinees study, a part of the Korean Genome and Epidemiology Study were used. The PRAL and NEAP scores were calculated to evaluate the dietary acid load. Hyperuricemia was defined as follows: >7.0 mg/dL and >6.0 mg/dL of serum uric acid levels in men and women, respectively. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of hyperuricemia. We identified 2500 new cases of hyperuricemia during a mean follow-up of 5.0 years (223,552 person years). The participants in the highest quartiles of the PRAL and NEAP score had 21% (HR: 1.21, 95% CI: 1.07–1.35, p for trend <0.0001) and 17% (HR: 1.17, 95% CI: 1.04–1.31, p for trend <0.0001) higher risks for hyperuricemia, respectively, than those in the lowest quartiles, after adjusting for covariates. In this prospective cohort study, a higher dietary acid load was positively associated with a higher incidence of hyperuricemia in Korean adults. This suggests that an alkaline diet may be an effective strategy to reduce the future risk of elevated uric acid levels.

Dietary patterns and risk for hyperuricemia in the general population: Results from the TCLSIH cohort study

OBJECTIVE

Prospective cohort studies linking dietary patterns and hyperuricemia (HUA) are limited, especially in Asian populations. The aim of this study was to prospectively investigate the association between various dietary patterns and risk for HUA in a general adult population.

METHOD

We used data from the TCLSIH (Tianjin Chronic Low-grade Systemic Inflammation and Health) cohort study of 20 766 men and women who were free from HUA, cancer, and cardiovascular disease at baseline. Dietary patterns at baseline were identified with factor analysis based on responses to a validated 81-item food frequency questionnaire. HUA was defined as serum uric acid levels >420 μmol/L in men and >350 μmol/L in women. Cox proportional hazards regression models were used to examine the association of dietary patterns with incident HUA.

RESULTS

In all, 4389 first incident cases of HUA occurred during 73 822 person-years of follow-up (median follow-up of 4.2 y). Three main dietary patterns were extracted. They were the vegetable, sweet food, and animal food patterns. After adjusting for demographic characteristics, lifestyle factors, other dietary pattern scores, and inflammatory markers, comparing the highest with the lowest quartiles of dietary pattern scores, the multivariable hazard ratios (95% confidence interval) of HUA were 0.79 (0.72-0.87; P_trend < 0.0001) for the vegetable pattern, 1.22 (1.12-1.33; P_trend < 0.0001) for the sweet food pattern, and 1.24 (1.13-1.37; P_trend < 0.0001) for the animal food pattern.

CONCLUSIONS

Dietary patterns rich in animal or sweet foods were positively associated with a higher risk for HUA, whereas the vegetable pattern was negatively associated.

Gout associated with reduced renal excretion of uric acid. Renal tubular disorder that nephrologists do not treat

Gout is recurrent inflammatory arthritis caused by the deposition of monosodium urate crystals in the joints. The risk factors that predispose to suffering from gout include non-modifiable factors such as gender, age, ethnicity and genetics, and modifiable factors such as diet and lifestyle. It has been shown that the heritability of uric acid levels in the blood is greater than 30%, which indicates that genetics play a key role in these levels. Hyperuricaemia is often a consequence of reduced renal urate excretion since more than 70% is excreted by the kidneys, mainly through the proximal tubule. The mechanisms that explain that hyperuricaemia associated with reduced renal urate excretion is, to a large extent, a proximal renal tubular disorder, have begun to be understood following the identification of two genes that encode the URAT1 and GLUT9 transporters. When they are carriers of loss-of-function mutations, they explain the two known variants of renal tubular hypouricaemia. Some polymorphisms in these genes may have an opposite gain-of-function effect, with a consequent increase in urate reabsorption. Conversely, loss-of-function polymorphisms in other genes that encode transporters involved in urate excretion (ABCG2, ABCC4) can lead to hyperuricaemia. Genome-wide association study (GWAS) methods have made it possible to locate new gout-related loci associated with reduced renal urate excretion (NIPAL1, FAM35A).

Dietary Nutrients and Cardiovascular Risk Factors among Renal Transplant Recipients

Cardiovascular disease (CVD) is the leading cause of mortality in post-renal transplant recipients (RTRs). Adequate nutrient intake is a protective factor for CVD. We examined the associations of macronutrients and micronutrients with traditional and nontraditional CVD risk factors. Conducted from September 2016 to June 2018, this cross-sectional study included 106 RTRs aged ≥18 years with a functioning allograft. Dietary intake data from 3-day dietary records were collected. Nutrient intake adequacy was defined using various instruments, including the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines. CVD risk factors were defined according to the K/DOQI guidelines. Bivariate and multivariate logistic regression models were used to analyze the associations. CVD risk was present in all patients; the lowest proportions of adequate intake were 2.8% for dietary fiber and 0.9% for calcium. Adequate nutrient intake was associated with a lower likelihood of the occurrence of traditional CVD risk factors (specifically, 1.9-31.3% for hyperlipidemia and 94.6% for diabetes mellitus). It was also associated with a lower likelihood of the occurrence of nontraditional CVD risk by 0.8% for hypophosphatemia and 34% for hyperuricemia. Adherence to dietary guidelines should be promoted among RTRs to decrease CVD risk.

From purines to purinergic signalling: molecular functions and human diseases

Purines and their derivatives, most notably adenosine and ATP, are the key molecules controlling intracellular energy homoeostasis and nucleotide synthesis. Besides, these purines support, as chemical messengers, purinergic transmission throughout tissues and species. Purines act as endogenous ligands that bind to and activate plasmalemmal purinoceptors, which mediate extracellular communication referred to as "purinergic signalling". Purinergic signalling is cross-linked with other transmitter networks to coordinate numerous aspects of cell behaviour such as proliferation, differentiation, migration, apoptosis and other physiological processes critical for the proper function of organisms. Pathological deregulation of purinergic signalling contributes to various diseases including neurodegeneration, rheumatic immune diseases, inflammation, and cancer. Particularly, gout is one of the most prevalent purine-related disease caused by purine metabolism disorder and consequent hyperuricemia. Compelling evidence indicates that purinoceptors are potential therapeutic targets, with specific purinergic agonists and antagonists demonstrating prominent therapeutic potential. Furthermore, dietary and herbal interventions help to restore and balance purine metabolism, thus addressing the importance of a healthy lifestyle in the prevention and relief of human disorders. Profound understanding of molecular mechanisms of purinergic signalling provides new and exciting insights into the treatment of human diseases.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively.

RESULTS

In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (β = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (β = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting.

CONCLUSIONS

Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

Shellfish consumption and health: A comprehensive review of human studies and recommendations for enhanced public policy

Shellfish, including various species of mollusks (e.g., clams, oysters, and mussels) and crustaceans (e.g., shrimp and crab), have been a cornerstone of healthy dietary recommendations. However, beyond providing basic nutrition needs, their health-promoting effects have been suggested to include inflammation reduction and prevention of various chronic non-communicable diseases. Currently, studies on the association between shellfish consumption and health outcomes have reported conflicting results. The present comprehensive review summarized the latest studies on shellfish consumption and synthesized the available evidence on the potential health benefits or risks of shellfish consumption. The findings demonstrated that shellfish consumption may increase the risk of hyperuricemia and gout but may not increase the risk of type 2 diabetes, cardiovascular diseases, and thyroid cancer. Adequate evidence is lacking on the association between shellfish consumption and the risk of colorectal cancer, pancreatic cancer, oral cancer, endometriosis, hip fracture, cognitive function, wheeze, eczema and food allergy. Raw shellfish consumption may cause gastroenteritis and other diseases infected by bacteria or viruses. This review thus provides consumers and other relevant stakeholders with the latest evidence-based information on the potential benefits and risks of shellfish consumption.

Gender-Specific Inverse Associations Between Beans Intake, Serum Urate Levels, and Hyperuricemia: A Cross-Sectional Analysis Based on the Henan Rural Cohort Study

Background and Aims: Beans are rich in purines, which are important substances that lead to elevated serum urate, especially exogenous purines. Few studies were conducted to assess the relationship between beans intake and serum urate or hyperuricemia, especially in rural people. The purpose of this study was to validate the association by gender in the rural Chinese population.

Methods: A total of 38,855 participants aged 18–79 years old were enrolled from the Henan Rural Cohort Study (Registration number: ChiCTR-OOC-15006699). Dietary data were collected using a validated food frequency questionnaire (FFQ). Linear regression models and logistic regression models were used to examine the associations between beans intake and serum urate levels or hyperuricemia. Restricted cubic spline regression was performed to display the dose–response relationship.

Results: In multivariate-adjusted linear regression, an inverse correlation was found between beans intake and serum urate level (the highest quartile Q4 vs. the bottom quartile Q1) in both men (P = 0.008) and women (P < 0.001). Per 10-g increment in beans intake was associated with 0.30 μmol/L decreased concentration of serum urate in men and 0.71 μmol/L in women. The multivariate-adjusted odds ratios (ORs) of hyperuricemia were 0.83 (0.71, 0.97) in men and 0.73 (0.63, 0.84) in women (Q4 vs. Q1). Per 10-g increment in beans intake created a 1% decreased risk of hyperuricemia in men and 3% in women. The cubic spline suggested a risk reduction for hyperuricemia with increasing intake of beans.

Conclusion: A higher beans intake was associated with a lower serum urate level and a reduced risk of hyperuricemia in both sexes, and the association was more pronounced in women.

The Association between Purine-Rich Food Intake and Hyperuricemia: A Cross-Sectional Study in Chinese Adult Residents

OBJECTIVE

To explore the correlation between purine-rich food intake and hyperuricemia in Chinese adult residents.

METHOD

A cross-sectional study was conducted on the purine-rich food intake of Chinese adult residents based on the China Health and Nutrition Survey (CHNS) in 2009. The subjects were divided into hyperuricemia group and nonhyperuricemia group according to serum uric acid level, and the differences of the sociodemographic information (age, gender, and region), health status (weight status, blood pressure, blood sugar status), living habits (alcohol consumption, smoking status) and food intake (purine-rich food, other food) were compared between the two groups. Logistic regressions investigated the associations between the daily intake of purine-rich food (animal-derived food and legumes) and hyperuricemia.

RESULTS

Eventually, 6813 subjects were included in our study, 1111 of them had hyperuricemia. The intake of seafood, legumes, red meat, and poultry all increased the risk of hyperuricemia (p < 0.05), while the intake of purine-rich fungi and purine-rich vegetables did not affect the occurrence of hyperuricemia. Animal-derived food was the main source of purine-rich food consumed by Chinese adult residents (140.67g/day), which had a great impact on hyperuricemia. Finally, after adjusting for gender, age, region, body mass index (BMI), alcohol consumption, hypertension, and refined grains intake, the risk of hyperuricemia increased by 2.40% and 1.10% for each increase of 10 g in animal-derived food intake (OR = 1.024, 95% CI: 1.018-1.030) and legumes intake (OR = 1.011, 95% CI: 1.003-1.019), respectively.

CONCLUSION

The intake of animal-derived food and legumes were positively correlated with the occurrence of hyperuricemia. Controlling the intake of animal-derived food and legumes would be more beneficial to controlling the risk of hyperuricemia.

Sugar-sweetened beverage consumption and risk of hyperuricemia: a longitudinal analysis of the Health Workers Cohort Study participants in Mexico

BACKGROUND

The elevated consumption of sugar-sweetened beverages (SSBs) in Mexico is an important public health concern. However, the association between SSB consumption and hyperuricemia has been scarcely studied and not well documented.

OBJECTIVES

To prospectively evaluate the association between SSB consumption and risk of hyperuricemia in Mexican adults.

METHODS

A longitudinal analysis was conducted using data from the Health Workers Cohort Study. Participants were followed from 2004 to 2018, with measurements every 6 y. The analysis sample consisted of 1300 adults, aged 18 to 85 y. SSB consumption during the previous year was evaluated through a semiquantitative FFQ. Hyperuricemia was defined as a concentration of uric acid ≥7.0 mg/dL in men and ≥5.7 mg/dL in women. We evaluated the association of interest using 2 methodologies: fixed-effects logistic regression and generalized estimating equations (GEEs). Potential confounders were included in both approaches.

RESULTS

At baseline, median intake of SSBs was 472.1 mL/wk (IQR: 198.8-1416.4 mL/wk), and 233 participants had hyperuricemia. Uric acid was higher in participants with an SSB intake ≥7 servings/wk, compared with those with an intake <1 serving/wk (P < 0.001). Participants who changed from the lowest to the highest category of servings consumption experienced 2.6 increased odds of hyperuricemia (95% CI: 1.27, 5.26). Results from the GEE model indicated the odds of hyperuricemia increased by 44% (OR=1.44; 95% CI: 1.13, 1.84) in the 2-6 servings/wk group, and by 89% (OR=1.89; 95% CI: 1.39, 2.57) in the ≥7 servings/wk categories, compared with the <1 serving/wk category. Diet soft drinks were not associated with hyperuricemia.

CONCLUSIONS

Our results suggest that the consumption of SSBs is associated with an increased risk of hyperuricemia in Mexican adults, but diet soft drink consumption is not, which supports the need to strengthen existing recommendations to reduce the intake of SSBs.The Health Workers Cohort Study (HWCS) has been approved by the Institutional Review Board of the Mexican Social Security Institute (12CEI 09 006 14), and the National Institute of Public Health of Mexico (13CEI 17 007 36).

Prevalence and Risk Factors of Hyperuricemia in Patients with Chronic Kidney Disease and Non-Alcoholic Fatty Liver

Background/Aims

The number of patients with nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) is on the rise. Epidemiological studies have shown the role of hyperuricemia in the development of NAFLD and CKD through oxidative stress and inflammatory mediators. Therefore, this study was conducted to investigate the prevalence and risk factors of hyperuricemia in patients with CKD and NAFLD in Iran.

Patients and Methods

This study was conducted in 450 CKD patients. NAFLD was diagnosed by ultrasonography. According to the serum uric acid level, all CKD⁺ NAFLD⁺ patients were divided into non-hyperuricemia and hyperuricemia groups. The patients' demographic and clinical data such as age, sex, abdominal obesity, metabolic syndrome, diabetes, hypertension, CRP, hepatic steatosis, blood pressure, serum uric acid (UA), lipid and creatinine were collected for analysis.

Results

A total of 279 cases (62%) were diagnosed with NAFLD. The prevalence rate of NFALD in CKD patients was significantly lower in normal UA level than hyperuricemia (42.7% vs 57.3%) (P=0.039). The prevalence of hyperuricemia was about 57.3% in patients with CKD and NAFLD. Accordingly, 279 CKD patients with NAFLD were enrolled and divided into hyperuricemia (n =160) and non-hyperuricemia groups (n =119). Patients with hyperuricemia showed higher creatinine and lipid levels, and a lower GFR compared to patients with normal uric acid levels (P< 0.05). However, no significant difference was observed in age, sex, abdominal obesity, metabolic syndrome, hypertension, type 2 diabetes, CRP, and steatosis between hyperuricemia and non-hyperuricemia groups (P>0.05). Three factors, including type 2 diabetes, hyperlipidemia, and a low GFR, serve as independent risk factors for hyperuricemia (P<0.05).

Conclusion

The results showed a high prevalence of hyperuricemia in patients with CKD and NAFLD. A more comprehensive strategic management is necessary to address the potential harmful effects of hyperuricemia on the health of CKD⁺ NAFLD⁺ cases.

Update on the epidemiology, genetics, and therapeutic options of hyperuricemia

Hyperuricemia may occur when there is an excess of uric acid in the blood. Hyperuricemia may result from increased production or decreased excretion of uric acid. Elevated uric acid levels are a risk factor for gout, and various risk factors, including some medications, alcohol consumption, kidney disease, high blood pressure, hypothyroidism, and pesticide exposure, as well as obesity, are associated with an elevated risk of hyperuricemia. Although the mechanisms underlying the pathogenesis of hyperuricemia are complex, previously reported studies have revealed that hyperuricemia is involved in a variety of biological processes and signaling pathways. In this review, we summarize common comorbidities related to hyperuricemia and describe an update of epidemiology, pathogenesis, and therapeutic options of hyperuricemia. This systematic review highlights the epidemiology and risk factors of hyperuricemia. Moreover, we discuss genetic studies on hyperuricemia to uncover current status and advances in the pathogenesis of hyperuricemia. Additionally, we conclude with a reflection on the underlying mechanisms of hyperuricemia and present the alternative drug strategies for the treatment of hyperuricemia to offer more effective clinical interventions.

Hyperuricemia versus lifestyle in men and women of the Russian Federation population

Objective ― Analyzing gender-related specificities of hyperuricemia associations with lifestyle choices in the Russian Federation (RF) population. Material and Methods ― Cross-sectional survey was performed within the guidelines of the Russian national multicenter study ESSE-RF. The final sample size was 20781 people 25-64 years old. The effect of age, body mass index (BMI), diet, smoking status, and alcohol consumption on the incidence of hyperuricemia was evaluated. The analysis was carried out separately for men and women, using logistic regression. To build a model for predicting hyperuricemia, classification trees were used. Results ― Multidirectional associations of hyperuricemia were revealed both in women (with BMI, age, ‘Smart’ dietary pattern, alcohol consumption) and in men (with BMI, ‘smart’ dietary pattern, alcohol consumption, smoking status). The predictive accuracy of hyperuricemia incidence models was 60.4% in women vs. 65.7% in men. In both gender groups, BMI had the highest contribution to predicting the hyperuricemia incidence, while the next predictors, in terms of significance, differed among men and women. In women, the greatest impact, in decreasing order, was exerted by age, dietary patterns and drinking, whereas in men, by smoking status, dietary patterns and drinking. Conclusion ― In the RF population, there are multiple gender-specific associations of hyperuricemia with lifestyle choices, particularly nutrition, smoking and alcohol consumption.