The association of dietary intake of purine-rich vegetables, sugar-sweetened beverages and dairy with plasma urate, in a cross-sectional study

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.

Fangyukangsuan granules ameliorate hyperuricemia and modulate gut microbiota in rats

Hyperuricaemia (HUA) is a metabolic disorder characterised by high blood uric acid (UA) levels; moreover, HUA severity is closely related to the gut microbiota. HUA is also a risk factor for renal damage, diabetes, hypertension, and dyslipidaemia; however, current treatments are associated with detrimental side effects. Alternatively, Fangyukangsuan granules are a natural product with UA-reducing properties. To examine their efficacy in HUA, the binding of small molecules in Fangyukangsuan granules to xanthine oxidase (XOD), a key factor in UA metabolism, was investigated via molecular simulation, and the effects of oral Fangyukangsuan granule administration on serum biochemical indices and intestinal microorganisms in HUA-model rats were examined. Overall, 24 small molecules in Fangyukangsuan granules could bind to XOD. Serum UA, creatinine, blood urea nitrogen, and XOD levels were decreased in rats treated with Fangyukangsuan granules compared to those in untreated HUA-model rats. Moreover, Fangyukangsuan granules restored the intestinal microbial structure in HUA-model rats. Functional analysis of the gut microbiota revealed decreased amino acid biosynthesis and increased fermentation of pyruvate into short-chain fatty acids in Fangyukangsuan granule-treated rats. Together, these findings demonstrate that Fangyukangsuan granules have anti-hyperuricaemic and regulatory effects on the gut microbiota and may be a therapeutic candidate for HUA.

Study on the mechanism of Orthosiphon aristatus (Blume) Miq. in the treatment of hyperuricemia by microbiome combined with metabonomics

ETHNOPHARMACOLOGICAL RELEVANCE

Growing evidence indicates that hyperuricemia is closely associated with gut microbiota dysbiosis. Orthosiphon aristatus (Blume) Miq. (O. aristatus), as a traditional Chinese medicine, has been widely used to treat hyperuricemia in China. However, the mechanism by which O. aristatus treats hyperuricemia has not been clarified.

AIM OF THE STUDY

In this study, we investigated whether the molecular mechanism underlying the anti-hyperuricemia effect of O. aristatus is related to the regulation of gut microbiota by 16S rDNA gene sequencing combined with widely targeted metabolomics.

MATERIALS AND METHODS

Hyperuricemia was induced in rats by administration of 10% fructose and 20% yeast, and the uricosuric effect was assessed by measuring the uric acid (UA) levels in serum and cecal contents. Intestinal morphology was observed by hematoxylin and eosin (HE) staining. To explore the effects of O. aristatus on the gut microbiota and its metabolites, we utilized 16S rDNA gene sequencing combined with widely targeted metabolomics. Furthermore, metabolic pathway enrichment analysis was performed on the screened differential metabolites. The real time quantitative polymerase chain reaction (RT-PCR) and western blotting (WB) were used to detect the expression of relevant proteins in the key pathway.

RESULTS

Our results indicated that O. aristatus intervention decreased serum UA levels and increased the UA levels in cecal contents in hyperuricemic rats. Additionally, O. aristatus improved intestinal morphology and altered the composition of the gut microbiota and its metabolites. Specifically, 16S rDNA revealed that O. aristatus treatment significantly reduced the abundance of unidentified-Ruminococcaceae and Lachnospiraceae-NK4A136-group. Meanwhile, widely targeted metabolomics showed that 17 metabolites, including lactose, 4-oxopentanoate and butyrate, were elevated, while 55 metabolites, such as flavin adenine dinucleotide and xanthine, were reduced. Metabolic pathway enrichment analysis found that O. aristatus was mainly involved in purine metabolism. Moreover, RT-PCR and WB suggested that O. aristatus could significantly up-regulate the expression of UA excretion transporter ATP-binding cassette subfamily G member 2 (ABCG2) in the intestine.

CONCLUSION

O. aristatus exerts UA-lowering effect by regulating the gut microbiota and ABCG2 expression, indicating that this herb holds great promise in the treatment of hyperuricemia.

Screening and application of purine degrading Limosilactobacillus fermentum LF-1 from Huangjiu fermentation broth

BACKGROUND

As the important building blocks of nucleic acids, purines are alkaloids and responsible for hyperuricemia and gout. The purine content in Huangjiu is higher, and mainly exists in the form of free bases, which is easier to be absorbed by human body. However, the currently available reports on purine in Huangjiu mainly focus on detection methods and content survey. No studies on the regulation of the purine content in Huangjiu have been reported.

RESULTS

Eighty-four strains, with the degradation capacity of purine, were screened from the fermentation broth of Huangjiu. In detail, the isolated lactic acid bacteria (LAB) strain 75 # showed the strongest degradation ability of guanosine, inosine and four purines, which reduce their levels by 83.4% (guanosine), 97.4% (inosine), 95.1% (adenine), 95.0% (guanine), 94.9% (hypoxanthine) and 65.9% (xanthine), respectively. Subsequently, the LAB strain 75# was identified to be Limosilactobacillus fermentum by 16S rRNA gene sequencing, which was named as Limosilactobacillus fermentum LF-1 and applied to the fermentation of Huangjiu in the laboratory. Compared with the fermentation broth of Huangjiu without adding L. fermentum LF-1, the content of purine compounds in the fermentation broth inoculated with L. fermentum LF-1 was reduced by 64.7%. In addition, the fermented Huangjiu had richer flavor compounds, and the physicochemical indices were in accordance with the national standard of Chinese Huangjiu.

CONCLUSION

The screened strain L. fermentum LF-1 may be a promising probiotic for the development of a novel that can efficiently degrade purine in Huangjiu. © 2023 Society of Chemical Industry.

Popular Diets and Kidney Stones

Popular diets often influence dietary patterns, which have different implications for kidney stone risk. Despite the wide variety of popular diets, some general principles can be gleaned from investigating their potential impact on nephrolithiasis. Plant-based diets, including Dietary Approaches to Stop Hypertension, Mediterranean, flexitarian, and vegetarian diets, may protect against nephrolithiasis when they consist largely of unprocessed plant foods, while carbohydrate-restricted diets (including high-protein diets and the ketogenic diet) may raise kidney stone risk. Patients should be advised to consume a diet rich in whole plants, particularly fruits and vegetables, and minimize their consumption of animal proteins. Accompanying fruits and vegetables that are higher in oxalate content with more water and some dairy intake may also be useful. (We address the oxalate content of fruits and vegetables further below). Calcium consumption is an important component of decreasing the risk of kidney stones, as higher dietary calcium from dairy or nondairy sources is independently associated with lower kidney stone risk. Patients should also be advised to be conscious of fat intake, as fat in the intestinal lumen may complex with calcium and therefore increase urinary oxalate excretion. Finally, patients should avoid consumption of processed foods, which often contain added fructose and high sodium content, two factors that increase kidney stone risk.

Diurnal Variations in Serum Uric Acid, Xanthine, and Xanthine Oxidoreductase Activity in Male Patients with Coronary Artery Disease

Hyperuricemia is influenced by diet and can cause gout. Whether it is a potential risk factor for cardiovascular disease (CVD) remains controversial, and the mechanism is unclear. Similar to CVDs, gout attacks occur more frequently in the morning and at night. A possible reason for this is the diurnal variation in uric acid (UA), However, scientific data regarding this variation in patients with CVD are not available. Thus, we aimed to investigate diurnal variations in serum levels of UA and plasma levels of xanthine, hypoxanthine, and xanthine oxidoreductase (XOR) activity, which were measured at 18:00, 6:00, and 12:00 in male patients with coronary artery disease. Thirty eligible patients participated in the study. UA and xanthine levels significantly increased from 18:00 to 6:00 but significantly decreased from 6:00 to 12:00. By contrast, XOR activity significantly increased both from 18:00 to 6:00 and 6:00 to 12:00. Furthermore, the rates of increase in UA and xanthine levels from night to morning were significantly and positively correlated. In conclusion, UA and xanthine showed similar diurnal variations, whereas XOR activity showed different diurnal variations. The morning UA surge could be due to UA production. The mechanism involved XOR activity, but other factors were also considered.

Comparative study and relationship analysis between purine content, uric acid, superoxide dismutase, and growth traits in purebred and crossbred Thai native chickens

The objective was to compare and analyze the relationship between growth, purine content, uric acid, and superoxide dismutase (SOD) in purebred and crossbred Thai native chickens. A total of 300 Thai native chickens were divided into 3 groups. Group 1 was purebred Thai native chickens (100%TN), Group 2 was 50% Thai native chickens (50%TN), and Group 3 was 25% Thai native chickens (25%TN). Data included the body weight (BW), average daily gain (ADG), and breast circumference (BrC). At 6, 8, and 10 weeks of age, 10 chickens from each group were randomly euthanized to collect breast meat, liver, and blood samples to analyze the purine content consisting of total purine, adenine, guanine, xanthine, and hypoxanthine, and uric acid, in breast meat and liver and SOD in blood. A general linear model, Pearson correlation and principal component analysis were used to analyze the significant differences and relationship between variables. The results showed the 25%TN group had the highest growth traits at every age, while the 100%TN group had the lowest (p < 0.05). Consistent with the analysis results of purine values, purine content and uric acid in breast meat and liver and SOD in blood decreased with age (p < 0.05). The correlations between purine content (total purine, adenine, guanine, xanthine, and hypoxanthine) and growth traits (BW, ADG, and BrC) ranged from moderate negative to moderate positive (-0.542 to 0.253)(p < 0.05). The correlations between uric acid and growth traits (0.348-0.760) and SOD and growth traits (0.132-0.516) were low to moderate positive with significant differences (p < 0.05). The principal component plot, which highlighted three principal components (PC 1, PC 2, and PC 3), explained 86.44 and 86.53% of the total information in breast meat and liver for selecting animals for optimal balance of the variation in the growth traits, purine content, uric acid, and SOD. Although purebred Thai native chickens showed the lowest growth traits, purine content, uric acid, and SOD were also lowest compared to crossbred Thai native chickens. Therefore, the development of genetics in Thai native chickens to produce healthy food could be possible.

In vivo anti-hyperuricemia and anti-gouty arthritis effects of the ethanol extract from Amomumvillosum Lour

The incidence of hyperuricemia and gout has been increasing year by year, and it is showing a younger trend. However, the first-line drugs currently used for hyperuricemia and gouty arthritis have serious side effects that limit their clinical application. Amomum villosum Lour. has been widely used in China for thousands of years as a traditional medical and edible plant, and previous screening showed that the ethanol extract of Amomum villosum Lour. could effectively inhibit the activity of xanthine oxidase. Based on this discovery, this paper had achieved in-depth mechanism research. The results showed that the ethanol extract of Amomum villosum Lour. could treat hyperuricemia by reducing the production of uric acid via inhibition of xanthine oxidase and increasing the excretion of uric acid via regulation of urate transporters. Meanwhile, the extract also showed a certain protective effect on hepatic and renal damage caused by hyperuricemia. With the formation of extensive uric acid, gouty arthritis will be induced by the deposition of monosodium urate in the joint. The extract could also relieve the inflammation by reducing the expression of inflammatory cytokines. In conclusion, the extract deserves focused research and development as a potential medicine, health care product or supplemented food for the prevention and treatment of hyperuricemia and gouty arthritis.

Adherence to DASH Dietary Pattern and Its Association with Incident Hyperuricemia Risk: A Prospective Study in Chinese Community Residents

Hyperuricemia represents a great burden on global public health, and it is important to provide effective guidance at the level of dietary patterns. We evaluated the association between the Dietary Approaches to Stop Hypertension (DASH) diet and the risk of hyperuricemia in a large-scale, community-based cohort in East China. In total, 45,853 participants that did not have either hyperuricemia nor gout were included and assigned a DASH dietary score based on their baseline dietary intake. They were then divided into five quintiles (Q1−Q5) according to their score, followed by cross-linkages with local health information systems and in-person surveys. Cox proportional hazards models were adopted to calculate hazard ratio (HR) and 95% confidence intervals (CIs). During a median follow-up of 4.54 years, 2079 newly diagnosed hyperuricemia cases were documented. Compared to the DASH Q1 group, the risk of incident hyperuricemia for the Q5 group was significantly reduced by 16% (HR: 0.84; 95% CIs: 0.72−0.97) in the adjusted model. The associations of DASH diet with hyperuricemia appeared stronger (P for interaction <0.001) among participants with 3−4 cardiometabolic diseases at baseline, compared with their counterparts. Our results suggest that the DASH diet could be taken into account in the recognition of risk population and the prevention of hyperuricemia.

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.

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.

Effects of Sporisorium reiliana polysaccharides and Phoenix dactylifera monosaccharides on the gut microbiota and serum metabolism in mice with fructose-induced hyperuricemia

In recent decades, the prevalence of hyperuricemia has increased, and dietary fructose is an important risk factor for the development of this disease. This study investigated and compared the effects of Sphacelotheca reiliana polysaccharides and Phoenix dactylifera monosaccharides on a series of physiological and biochemical indicators and on the metagenomes and serum metabolites in mice with hyperuricemia caused by a high-fructose diet. S. reiliana polysaccharides inhibited uric acid biosynthesis and promoted uric acid excretion, thereby alleviating the hyperuricemia phenotype. In addition, hyperuricemia was closely related to the gut microbiota. After treatment with S. reiliana polysaccharides, the abundances of Bacteroidetes and Proteobacteria in the mouse intestines were decreased, the expression of genes involved in glycolysis/gluconeogenesis metabolic pathways and purine metabolism was downregulated, and the dysfunction of the gut microbiota was alleviated. With regard to serum metabolism, the abundance of hippuric acid, uridine, kynurenic acid, propionic acid and arachidonoyl decreased, and the abundances of serum metabolites in inflammatory pathways involved in kidney injury and gout, such as bile acid metabolism, purine metabolism and tryptophan metabolism pathways, decreased. P. dactylifera monosaccharides aggravated hyperuricemia. This research provides a valuable reference for the development of sugar applications.

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.

Probiotic Characterization of Lactobacillus brevis MJM60390 and In Vivo Assessment of Its Antihyperuricemic Activity

Uric acid is the final product of purine metabolism in human. The increase of serum uric acid is tightly related to the incidence of hyperuricemia and gout. Also, it has been reported that the intake of purine-rich foods like meat and seafood is associated with an increased risk of gout. Therefore, the reduction of purine absorption is one of therapeutic approaches to prevent hyperuricemia and gout. Currently, probiotics are being studied for the management of hyperuricemia and gout. In this study, we aimed to investigate the effect of Lactobacillus brevis MJM60390 on hyperuricemia induced by a high-purine diet and potassium oxonate in a mouse model. L. brevis MJM60390 among 24 lactic acid bacteria isolated from fermented foods showed the highest ability to assimilate inosine and guanosine in vitro and typical probiotic characteristics, like the absence of bioamine production, D-lactate production, hemolytic activity, as well as tolerance to simulated orogastrointestinal conditions and adherence to Caco-2 cells. In an in vivo animal study, the uric acid level in serum was significantly reduced to a normal level after oral administration of L. brevis MJM60390 for 2 weeks. The activity of xanthine oxidase catalyzing the formation of uric acid was also inhibited by 30%. Interestingly, damage to the glomerulus, Bowman's capsule, and tubules in the hyperuricemia model were reversed by supplementation with this strain. Fecal microbiome analysis revealed that L. brevis MJM60390 supplementation enhanced the relative abundance of the Rikenellaceae family, which produces the short-chain fatty acid butyrate and helps to maintain good gut condition. Therefore, these results demonstrated that L. brevis MJM60390 can be a probiotic candidate to prevent hyperuricemia.

Lactobacillus gasseri PA-3 reduces serum uric acid levels in patients with marginal hyperuricemia

Several studies have reported that Lactobacillus gasseri PA-3 reduces the level of serum uric acid (SUA) in patients with hyperuricemia. However, it remains unknown how PA-3 affects uric acid metabolism. In the present study, we examined effects of PA-3-containing yoghurt on uric acid metabolism in patients with marginal hyperuricemia. Sixteen patients with SUA > 357 μmol/L (marginal hyperuricemia) were enrolled. PA-3-containing yoghurt was administered for 8 weeks. Uric acid metabolism was evaluated just before and 8 weeks after the administration and at 4 weeks after the administration ended (post-administration). SUA levels after the administration were significantly lower than that before the administration and remained low at post-administration. Urinary uric acid concentration (Uur) after the administration were significantly lower than that before the administration. However, post-administration Uur levels were comparable to those before the administration. Therefore, PA-3-containing yoghurt significantly reduced the levels of SUA and Uur in patients with marginal hyperuricemia.

Dietary Pattern Associated with the Risk of Hyperuricemia in Chinese Elderly: Result from China Nutrition and Health Surveillance 2015–2017

Our current study aimed to estimate the relationship between dietary patterns and hyperuricemia among the Chinese elderly over 60 years old. All the data were obtained from China Nutrition and Health Surveillance during 2015–2017. A total of 18,691 participants who completed the whole survey were included in our statistical analysis. The definition of hyperuricemia was 420 μmmol/L (7 mg/dL) for male and 360 μmmol/L (6 mg/dL) for female. Exploratory factor analysis was applied to explore posterior dietary patterns in our samples, and five dietary patterns were recognized, namely “Typical Chinese”, “Modern Chinese”, “Western”, “Animal products and alcohol”, and “Tuber and fermented vegetables”. After multiple adjusted logistic regression, participants in the highest quartile of “typical Chinese” (Q4 vs. Q1, OR = 0.32, 95% CI: 0.28–0.37, p-trend < 0.0001), “modern Chinese” (Q4 vs. Q1, OR = 0.81, 95% CI: 0.71–0.93, p-trend = 0.0021) and “tuber and fermented vegetables” (Q4 vs. Q1, OR = 0.78, 95% CI: 0.69–0.88, p-trend < 0.0001) showed a lower risk of hyperuricemia, while animal products and alcohol was positively associated with hyperuricemia (Q4 vs. Q1, OR = 1.49, 95% CI: 1.31–1.7, p-trend < 0.0001). We also found that participants who mainly ate a modern Chinese diet tended to meet the RNI/AI of nutrients we discuss in this paper, which may supply some information for hyperuricemia prevention and management by dietary methods.

Hyperuricemia: Features of the Diet

The association of hyperuricemia (HU) with cardiovascular disease (CVD), diabetes, metabolic syndrome, and kidney disease has been demonstrated in numerous studies. НU is the main pathogenetic factor in the development of gout and is associated with an increase in overall and cardiovascular mortality. НU is included in the list of factors determining cardiovascular risk. According to epidemiological studies, there is a high prevalence of HU in the world and its increase in recent decades. A number of factors have been identified that contribute to the increased risk of НU. Non-modifiable factors include gender, age, genetic factors, and modifiable factors include diet and lifestyle. Nutritional unbalances, increased life expectancy, increased prevalence of obesity, and increased use of drugs (especially diuretics) are seen as contributing factors to the rise in НU. The review was carried out to summarize the available information on the effect of dietary habits, individual foods and nutrients on serum uric acid (SUA) levels and the risk of developing HU. The review presents the results of scientific studies demonstrating the relationship of НU with the consumption of foods rich in purines (offal, red meat, fish, seafood, legumes), alcohol consumption, drinks sweetened with fructose, coffee, dairy products, vegetables and fruits. Diet correction is an important and necessary step in the prevention and treatment of НU. The article reviews the basic principles of dietary management in HU and provides dietary recommendations for patients. For effective prevention and treatment of НU, a mandatory correction of the diet is required.

The impact of physiological metabolite levels on serine uptake, synthesis and utilization in cancer cells

Serine is a non-essential amino acid that is critical for tumour proliferation and depletion of circulating serine results in reduced tumour growth and increased survival in various cancer models. While many cancer cells cultured in a standard tissue culture medium depend on exogenous serine for optimal growth, here we report that these cells are less sensitive to serine/glycine depletion in medium containing physiological levels of metabolites. The lower requirement for exogenous serine under these culture conditions reflects both increased de novo serine synthesis and the use of hypoxanthine (not present in the standard medium) to support purine synthesis. Limiting serine availability leads to increased uptake of extracellular hypoxanthine, sparing available serine for other pathways such as glutathione synthesis. Taken together these results improve our understanding of serine metabolism in physiologically relevant nutrient conditions and allow us to predict interventions that may enhance the therapeutic response to dietary serine/glycine limitation.

Cancer cells in culture are often grown in media conditions containing unphysiological metabolite levels. Here, the authors grow cells under physiological metabolite levels to further understand the reliance of cells on serine and find that when grown under these conditions the cells are less sensitive to serine withdrawal.

Impact of Coffee/Green Tea/Soft Drink Consumption on the Risk of Hyperuricemia: A Cross-Sectional Study

This cross-sectional study aimed to investigate the association between hyperuricemia and the frequency of coffee, tea, and soft drink consumption, based on data from the Korean Genome and Epidemiology Study (KoGES) (2004-2016). We used the KoGES health examinee data, obtained from urban residents aged ≥ 40 years. Information on the participants' medical history, nutrition (total calorie, protein, fat, and carbohydrate intake), frequency of alcohol consumption, smoking status, household income, and frequency of coffee/green tea/soft drink intake was collected. A logistic regression model was used to analyze the data. Subgroup analyses were performed according to the participant's age and sex. Among 173,209 participants, there were 11,750 and 156,002 individuals with hyperuricemia and non-hyperuricemia controls, respectively. In an adjusted model, frequent coffee and green tea consumption did not increase the risk of hyperuricemia, compared to the "no intake" reference group. However, an adjusted odds ratio of hyperuricemia was 1.23 (95% confidence interval, 1.11-1.35, p < 0.001) for participants who reported consuming soft drinks ≥ 3 times per day, compared to the respective "no drink" reference group. Even after adjusting for nutritional and sociodemographic factors, frequent soft drink intake was associated with an increased risk of hyperuricemia. Meanwhile, neither coffee nor green tea intake was associated with an increased risk of hyperuricemia.

Sugar-sweetened soft drinks consumption and risk of hyperuricemia: Results of the ELSA-Brasil study

BACKGROUND AND AIMS

The prospective association between sugar-sweetened beverages consumption and hyperuricemia is controversial. The aim was to investigate the association of the consumption of sugar-sweetened soft drinks and unsweetened fruit juices with the incidence of hyperuricemia and the levels of serum uric acid in the participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS AND RESULTS

Longitudinal analysis in ELSA-Brasil participants (baseline 2008-2010 and follow-up 2012-2014). The sample consisted of 10,072 civil servants (35-74 years, both sexes). The consumption of beverages estimated by a food frequency questionnaire (baseline) was divided into five categories: nonconsumption and quartiles (≥0.1 mL/day). Hyperuricemia was defined as uric acid ≥7.0 mg/dL (men) and ≥5.7 mg/dL (women). Poisson regression with robust variance and multiple linear regression were tested. The average consumption of soft drinks was 84 ± 191 mL/day in men and 42 ± 128 mL/day in women. After 4 years of follow-up, the higher consumption of soft drinks (men: 401 ± 303 mL/day; women: 390 ± 290 mL/day) increased the relative risk of hyperuricemia by 30% (men) and 40% (women), and was associated with increased mean uric acid (men: β = 0.14 mg/dL; 95% CI 0.41-0.24; women: β = 0.11 mg/dL; 95% CI 0.00-0.21). The consumption of unsweetened juice was not associated with hyperuricemia.

CONCLUSION

High consumption of sugar-sweetened soft drinks is associated with an increased relative risk of hyperuricemia and elevated serum uric acid levels in Brazilian adults.

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.

Hyperuricemia and Its Associated Factors Among Adult Staff Members of the Ethiopian Public Health Institute, Ethiopia

Background

Hyperuricemia is related not only to an increased risk of gouty arthritis but also to an increased risk of cardiovascular diseases, resistant hypertension, insulin resistance and progression of type 2 diabetes mellitus. However, to the best of our knowledge, the prevalence of hyperuricemia and its associated factors have rarely been assessed in Ethiopian populations. Therefore, this study aimed to determine the prevalence of hyperuricemia and its associated factors among adult staff members of the Ethiopian Public Health Institute.

Methods

An institution-based cross-sectional study was conducted from July 1 to October 28, 2018. A total of 402 study participants were selected using a simple random sampling technique. An interviewer-administered questionnaire was used to collect the data. A blood sample of approximately 5 mL was collected from each study participant after overnight fasting through standardized methods for biochemical tests, and analyses were carried out with an automated COBAS 6000 analyzer. Data analysis was performed by SPSS version 20 software. The factors associated with the outcome variable were identified by bivariable and multivariable logistic regression analyses, and a p value <0.05 was used to declare statistical significance.

Results

The mean age of the study participants was 37.13±10.5 (mean ± SD), and 51.5% of the participants were male. The overall prevalence of hyperuricemia (>5.7 mg/dL for females and >7 mg/dL for males) was found to be 31.0%. The multivariable logistic analysis revealed that age (AOR=1.59, 95% CI 1.01–2.78), sex (AOR=1.66, 95% CI 1.02–2.70), cigarette smoking (AOR=2.05, 95% CI 1.01–4.19) and serum low-density lipoprotein (LDL) (AOR=1.70, 95% CI 1.01–2.87) were significantly associated with hyperuricemia.

Conclusion

The prevalence of hyperuricemia was relatively high compared to similar studies. Early screening for hyperuricemia in the general population, especially in those who are smokers, of older age and with high serum LDL levels, is vital to control its adverse effects at an early stage.

The comparative effect of exposure to various risk factors on the risk of hyperuricaemia: diet has a weak causal effect

BACKGROUND

Prevention of hyperuricaemia (HU) is critical to the prevention of gout. Understanding causal relationships and relative contributions of various risk factors to hyperuricemia is therefore important in the prevention of gout. Here, we use attributable fraction to compare the relative contribution of genetic, dietary, urate-lowering therapy (ULT) and other exposures to HU. We use Mendelian randomisation to test for the causality of diet in urate levels.

METHODS

Four European-ancestry sample sets, three from the general population (n = 419,060) and one of people with gout (n = 6781) were derived from the Database of Genotypes and Phenotypes (ARIC, FHS, CARDIA, CHS) and UK Biobank. Dichotomised exposures to diet, genetic risk variants, BMI, alcohol, diuretic treatment, sex and age were used to calculate adjusted population and average attributable fractions (PAF/AAF) for HU (≥0.42 mmol/L [≥7 mg/dL]). Exposure to ULT was also assessed in the gout cohort. Two sample Mendelian randomisation was done in the UK Biobank using dietary pattern-associated genetic variants as exposure and serum urate levels as outcome.

RESULTS

Adherence to dietary recommendations, BMI (< 25 kg/m²), and absence of the SLC2A9 rs12498742 urate-raising allele produced PAFs for HU of 20 to 24%, 59 to 69%, and 57 to 64%, respectively, in the three non-gout cohorts. In the gout cohort, diet, BMI, SLC2A9 rs12498742 and ULT PAFs for HU were 12%, 49%, 48%, and 63%, respectively. Mendelian randomisation demonstrated weak causal effects of four dietary habits on serum urate levels (e.g. preferentially drinking skim milk increased urate, β = 0.047 mmol/L, P = 3.78 × 10^-8). These effects were mediated by BMI, and they were not significant (P ≥ 0.06) in multivariable models assessing the BMI-independent effect of diet on urate.

CONCLUSIONS

Diet has a relatively minor role in determining serum urate levels and HU. In gout, the use of ULT was the largest attributable fraction tested for HU.

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.

Gicht – auch eine Frage des Lebensstiles

Mit steigenden Harnsäurewerten steigt das Risiko einer Gicht. Da die Harnsäure-Homöostase von zahlreichen Lebensstilfaktoren beeinflusst wird, ist das Auftreten einer Gicht fast immer auch mit der Lebensweise assoziiert. Lange schon ist bekannt, dass die Zufuhr purinreicher Lebensmittel (z. B. Fleisch, Meeresfrüchte) über vermehrte Harnsäurebildung aus exogen zugeführten Purinen zu Gichtanfällen führen kann. Auch Fruktose-haltige Getränke haben über einen vermehrten Abbau von ATP bei der Verstoffwechslung von Fruktose eine Hyperurikämie zur Folge, wogegen bei vermehrter Alkoholzufuhr und Adipositas eine verminderte renale Harnsäureausscheidung für die Hyperurikämie ursächlich ist. Einige Lebensmittel (z. B. Milch, Kaffee) scheinen einen harnsäuresenkenden Effekt zu haben und können Patienten explizit empfohlen werden. Mit Blick auf den Lebensstil spielen jedoch nicht nur Ernährungsfaktoren (Lebensmittel) eine wichtige Rolle. So kommt es beim aktuell sehr populären Heilfasten durch die entstehende Ketose und häufig gleichzeitig zu geringer Flüssigkeitszufuhr zu einer verminderten Harnsäureausscheidung über die Niere und konsekutiv Harnsäureanstieg. Auch Extremsport wie Marathon stellt aufgrund der katabolen Stoffwechsellage (Ketose) und hohen mechanischen Belastung (Mikrotraumata) bereits arthrotisch vorgeschädigter Gelenke einen Risikofaktor für das gehäufte Auftreten von Gichtanfällen dar. Patienten mit einer Hyperurikämie sollten als Basismaßnahme immer über eine mögliche Ernährungsumstellung beraten werden, zumal die Hyperurikämie eng mit dem metabolischen Syndrom assoziiert ist, häufigen Stoffwechselkrankheiten wie Diabetes mellitus, Hyperlipidämien und Adipositas, die ebenfalls durch eine Lebensstilmodifikation günstig zu beeinflussen sind. Eine manifeste (langjährige) Gicht kann allerdings durch eine alleinige Ernährungsumstellung nur selten erfolgreich behandelt werden. Der Zusammenhang zwischen Lebensstil und Gicht ist seit Jahrhunderten bekannt. Leider beschränken sich die wenigen Studien zu diesem Thema meist auf epidemiologische Erhebungen, über die in dieser Arbeit eine Übersicht gegeben werden soll.

Mediation effect of body mass index on the association between spicy food intake and hyperuricemia in rural Chinese adults: the Henan rural cohort study

Background

The relationship of spicy food intake with hyperuricemia remains unknown. The objective of this study was to examine the association between spicy food intake and hyperuricemia, and whether this association was mediated by body mass index (BMI) in Chinese rural population.

Methods

38, 027 adults aged 18–79 years were recruited from the Henan Rural Cohort Study. Information on spicy food intake was obtained using a validated questionnaire survey. Multivariable logistic regression model was used to estimate the association between spicy food intake and hyperuricemia, multiple linear regression model was performed to estimate the relationships between spicy food intake, BMI and serum urate level. BMI was used as a mediator to evaluate the mediation effect.

Results

After adjusting for potential confounders, compared with no spicy food flavor, the odds ratio (OR) and 95% confidence interval (CI) of mild, middle, and heavy flavor for hyperuricemia were 1.09 (1.00–1.19), 1.10 (0.97–1.24), and 1.21 (1.10–1.46), respectively (P_trend = 0.017). Similarly, compared with those without intake in spicy food, the multivariable adjusted OR (95% CI) of 1-2 days/week, 3–5 days/week, and 6–7 days/week were 1.15 (1.01–1.31), 1.14 (1.01–1.30) and 1.15 (1.05–1.26), respectively (P_trend = 0.007). However, when we further controlling for BMI, the associations were substantially attenuated. Furthermore, mediation analysis showed that BMI play a full mediating role in the relationship of spicy food intake with hyperuricemia.

Conclusion

Spicy food flavor and intake frequency are positively related with hyperuricemia in Chinese rural population. BMI may play a full mediating role in the relationship.

Trial registration

The Henan Rural Cohort Study registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.

Determination of total purine and purine base content of 80 food products to aid nutritional therapy for gout and hyperuricemia

The aim of this work is to facilitate the nutritional therapy of gout and hyperuricemia. In Japan, patients with gout or hyperuricemia are recommended to consume less than 400 mg of dietary purines per day. When receiving nutritional therapy for gout or hyperuricemia, purine-rich foods (>200 mg/100 g) should be eaten in even lower quantities. The purine content of foods reported in this study are as follows: noodles, 0.6-12.1 mg/100 g; bread, 4.4 mg/100 g; peas or seeds, 19.6-67.1 mg/100 g; dairy, 0.0-1.4 mg/100 g; Japanese vegetables, 0.9-47.1 mg/100 g; seasonings, 0.7-847.1 mg/100 g; meat or fish, 19.0-385.4 mg/100 g; fish milt, 375.4-559.8 mg/100 g; and supplements, 81.9-516.0 mg/100 g. Foods containing very large amounts of purine (>300 mg/100 g) included anchovy, cutlassfish (hairtail), cod milt, globefish milt, dried Chinese soup stock, dried yeast, a Euglena supplement, and a Lactobacillus supplement. When eating these high-purine food or supplements, the quantity taken at one meal should be limited, especially milt because they typically consumed amount of 20-30 g is equivalent to 75-168 mg total purines. This is 20%-40% of the recommended daily amount (400 mg/day) for patients with gout or hyperuricemia. Thus, these patients should restrict the amount of purine-rich foods they consume. Good dietary habits with a good balance of nutrients are recommended.

Uric Acid as a Potential Peripheral Biomarker for Disease Features in Huntington's Patients

Oxidative stress has long been implicated in the pathophysiology and progression of Huntington's disease (HD). Uric acid (UA) is a naturally occurring antioxidant that is present in the brain and periphery. Growing evidence has implicated UA as a molecular biomarker for several neurodegenerative diseases, most notably Parkinson's disease (PD). In this study, we investigated UA levels in clinical samples from HD patients and normal controls (NCs) and assessed potential relationships between UA levels and disease and clinical data. UA levels were measured in plasma (n = 107) and saliva (n = 178) samples from premanifest (pre-HD) and manifest HD patients and control subjects. Gender effects of UA levels were observed in both biofluids, with male patients showing higher UA levels compared to female patients. Comparisons of UA levels across diagnostic groups, separated by gender, revealed that both plasma and salivary UA levels were significantly lower in female pre-HD and manifest HD patients compared to NCs. Salivary levels of UA were also significantly lower in male manifest HD patients versus controls, but not in plasma. Correlations of peripheral UA levels to clinical data also showed differences according to gender. In male HD patients, both plasma and salivary UA levels were significantly negatively correlated with total functional capacity (TFC), while positive correlations were observed with total motor score (TMS). Female HD patients showed a significant positive correlation between plasma UA levels and TMS, while salivary UA levels from female patients were significantly correlated to disease burden. Finally, in a separate cohort, we show that UA levels are decreased in postmortem prefrontal cortical samples (n = 20) from HD subjects compared to matched controls. These findings suggest that decreased levels of UA in the brains of HD patients can be reflected in peripheral fluids, with salivary measures of UA particularly offering significant promise as a potentially relevant, non-invasive biomarker of disease symptoms and burden. Our findings further highlight the impact of sexual dimorphism in HD pathophysiology.

Better outcomes for patients with gout

Gout is increasing in prevalence despite effective pharmacotherapies. Barriers to effective management are largely educational deficiencies. Sufferers, usually men, need to understand more about gout, especially that maintaining serum urate below 0.36 mmol/L will eliminate recurrent attacks. Also, of great importance is appreciating that sub-optimal adherence to urate-lowering therapy (ULT) will result in a return of attacks. Prescribers also need to understand that acute attacks are likely to occur in the first few months of urate-lowering therapy (ULT), but these can be mitigated by commencing with a dose of ULT reflective of renal function and escalating the dose slowly, every 2-5 weeks until target serum urate is achieved. Prophylaxis against acute attacks over the initial 6 months period of ULT can be enhanced further with concomitant colchicine or nonsteroidal anti-inflammatory drugs (NSAIDs).Gout is largely managed in primary care. Rates of adherence to ULT are 50% or less, worse than most other chronic illnesses. Efforts at educating primary care physicians to, firstly, manage gout effectively and, secondly, to educate their gout patients sufficiently have not been successful. Allied health practitioners, such as nurses, working with prescribers in primary care settings and given the mandate to educate and manage patients with gout, have been spectacularly effective. However, this approach is resource intensive. 'Personalised' eHealth interventions show promise as an alternative strategy, notably in improving adherence to ULT.Numerous applications for smart phones (apps) are now available to assist people with chronic health conditions. Their design needs to accommodate the barriers and enablers perceived by patients to maintaining adherence to prescribed therapies. Personalised feedback of serum urate may represent an important enabler of adherence to ULT in the case of gout.Harnessing mobile apps to support patients managing their chronic illnesses represents an important opportunity to enhance health outcomes. Rigorous, patient-centred and driven development is critical. These tools also require careful evaluation for effectiveness.

Association between dairy product consumption and hyperuricemia in an elderly population with metabolic syndrome

BACKGROUND AND AIMS

The prevalence of hyperuricemia has increased substantially in recent decades. It has been suggested that it is an independent risk factor for weight gain, hypertension, hypertriglyceridemia, metabolic syndrome (MetS), and cardiovascular disease. Results from epidemiological studies conducted in different study populations have suggested that high consumption of dairy products is associated with a lower risk of developing hyperuricemia. However, this association is still unclear. The aim of the present study is to explore the association of the consumption of total dairy products and their subtypes with the risk of hyperuricemia in an elderly Mediterranean population with MetS.

METHODS AND RESULTS

Baseline cross-sectional analyses were conducted on 6329 men/women (mean age 65 years) with overweight/obesity and MetS from the PREDIMED-Plus cohort. Dairy consumption was assessed using a food frequency questionnaire. Multivariable-adjusted Cox regressions were fitted to analyze the association of quartiles of consumption of total dairy products and their subtypes with the prevalence of hyperuricemia. Participants in the upper quartile of the consumption of total dairy products (multiadjusted prevalence ratio (PR) = 0.84; 95% CI: 0.75-0.94; P-trend 0.02), low-fat dairy products (PR = 0.79; 95% CI: 0.70-0.89; P-trend <0.001), total milk (PR = 0.81; 95% CI: 0.73-0.90; P-trend<0.001), low-fat milk (PR = 0.80; 95% CI: 0.72-0.89; P-trend<0.001, respectively), low-fat yogurt (PR = 0.89; 95% CI: 0.80-0.98; P-trend 0.051), and cheese (PR = 0.86; 95% CI: 0.77-0.96; P-trend 0.003) presented a lower prevalence of hyperuricemia. Whole-fat dairy, fermented dairy, and yogurt consumption were not associated with hyperuricemia.

CONCLUSIONS

High consumption of total dairy products, total milk, low-fat dairy products, low-fat milk, low-fat yogurt, and cheese is associated with a lower risk of hyperuricemia.

Impact of Lesinurad and allopurinol on experimental Hyperuricemia in mice: biochemical, molecular and Immunohistochemical study

BACKGROUND

Hyperuricemia is an abnormal increase in uric acid levels in the blood. It is the cause of gout that manifested by inflammatory arthritis and painful disable. Therefore, current study evaluated the potential ameliorative impact of Lesinurad and Allopurinol on the kidneys of hyperuricemic mice at the biochemical, molecular and cellular levels.

METHODS

Lesinurad and allopurinol alone or in combination were orally administered to hyperuricemic and control mice for seven consecutive days. Levels of uric acid and blood urea nitrogen, along with antioxidants and inflammatory cytokines (IL-1β and TNF-α) were measured in the serum. The mRNA expression of mouse urate anion transporter-1, glucose transporter 9, organic anion transporters, in renal tissues were examined using quantitative real time PCR. Simultaneously, the immunoreactivity of transforming growth factor-beta 1 was examined immunohistochemically.

RESULTS

Lesinurad and allopurinol administration resulted in significant decrease in serum levels of uric acid, blood urea nitrogen, xanthine oxidase activity, catalase, glutathione peroxidase and inflammatory cytokines (IL-1β and TNF-α) reported in hyperuricemic mice. Both partially reversed oxonate-induced alterations in renal mURAT-1, mGLUT-9, mOAT-1 and mOAT-3 expressions, as well as alterations in the immunoreactivity of TGF- β1, resulting in the increase of renal uric acid secretion and excretion. The combined administration of lesinurad and ALP restored all altered parameters in a synergistic manner, improving renal function in the hyperuricemic mouse model employed.

CONCLUSION

This study confirmed synergistic ameliorative hypouricemic impact of both lesinurad and allopurinol in the treatment of hyperuricemia in mice at the biochemical, molecular and cellular levels.

Comparisons of protective effects between two sea cucumber hydrolysates against diet induced hyperuricemia and renal inflammation in mice

Differences in the anti-hyperuricemic and anti-inflammation effects between two sea cucumber hydrolysates in diet induced hyperuricemic mice.

Influence of d-Amino Acids in Beer on Formation of Uric Acid

Excessive intake of beer could increase serum uric acid levels, leading to high risk of gout, which was previously attributed to high purine content in beer. Recent reports that purine-rich vegetables and bean products do not cause higher uric acid levels do not support this theory. Why excessive intake of beer could increase a high risk of gout has been unclear. Other factors affecting the accumulation of uric acid in the blood have been explored. Beer contains relatively high levels of d-amino acids due to the racemization of l-amino acids induced by food processing. d-amino acid was catalyzed by d-amino acid oxidase to produce H₂O₂, which is further oxidized in the presence of Fe²⁺ to produce hydroxyl radicals, resulting in DNA damage and formation of a large amount of purine bases, which are oxidized to uric acid by a series of enzymes. Some food ingredients, such as vitamins and I^-, prompt d-amino acids to form uric acid. d-amino acids in beer are one of the key factors responsible for the increase in uric acid levels. The biological response of d-amino acids could explain gout occurrence in beer drinkers.

Antihyperuricemic effect of dietary polyphenol sinapic acid commonly present in various edible food plants

The present study was conducted to evaluate the antihyperuricemic effect of sinapic acid (SA). The results showed that SA potently inhibited xanthine oxidase (XOD) in a dose-dependent manner by entering the enzyme active site and thwarting the entrance of the substrate. These results were further confirmed by the quantum chemical descriptors analysis and ¹ H NMR titration analysis. The in vivo results indicated that SA not only has the potential to inhibit serum and hepatic XOD (p < .05), but also remarkably lowered serum and urine uric acid levels at 50 and 100 mg/kg bw. Furthermore, SA regulated serum creatinine and blood urea nitrogen levels to normal and lowered inflammation in the renal tubules. Thus, the utilization of SA as an antihyperuricemic agent may have considerable potential for the development of functional foods for the possible treatment of hyperuricemia. PRACTICAL APPLICATIONS: Plant-derived bioactive compounds have multiple health benefits. The present study assesses the effects of sinapic acid against hyperuricemia. The results suggested that sinapic acid may have a strong protective effect against uric acid-related complications and may be used for the formulation of functional foods. However, further mechanistic studies are required to verify this hypothesis.

Intake of selected foods and beverages and serum uric acid levels in adults: ELSA-Brasil (2008–2010)

Objective:

To investigate the association between the intake of selected food groups and beverages and serum uric acid (UA).

Design:

Cross-sectional study using the baseline data (2008–2010) from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Food intake was assessed by food frequency questionnaire with 114 items. Linear and logistic regressions investigated the associations between the daily intake of each food group (servings/d) and UA (mg/dl) and hyperuricemia (UA ≥ 6·8 mg/dl), respectively. All the analyses were adjusted for potential confounders, energy intake and all food groups.

Setting:

Teaching and research institutions from six Brazilians states.

Subjects:

The participants were 14 320 active and retired civil servants, aged 35–74 years.

Results:

Higher intake of dairy products was associated with lower serum UA levels in both sexes, with a statistical dose-response gradient. High meat intake was associated with high UA only in women, and high intake of organ meats, in men. Intake of fish and fruits, vegetables and legumes were not associated with serum UA. In men, moderate and high intake of alcoholic beverages, specifically beer and spirits, but not wine, increased UA. In women, only high intake of alcoholic beverages, specifically beer, was associated with increased serum UA. Similar associations were seen for hyperuricemia.

Conclusions:

Results suggest a potential beneficial role of dairy products consumption on UA levels. The association between alcohol intake and UA differed according to type of beverage and between sexes. Results reinforce the need to consider the whole diet in the analysis and to conduct sex stratified analysis.

Evolution of (p)ppGpp-HPRT regulation through diversification of an allosteric oligomeric interaction

The alarmone (p)ppGpp regulates diverse targets, yet its target specificity and evolution remain poorly understood. Here, we elucidate the mechanism by which basal (p)ppGpp inhibits the purine salvage enzyme HPRT by sharing a conserved motif with its substrate PRPP. Intriguingly, HPRT regulation by (p)ppGpp varies across organisms and correlates with HPRT oligomeric forms. (p)ppGpp-sensitive HPRT exists as a PRPP-bound dimer or an apo- and (p)ppGpp-bound tetramer, where a dimer-dimer interface triggers allosteric structural rearrangements to enhance (p)ppGpp inhibition. Loss of this oligomeric interface results in weakened (p)ppGpp regulation. Our results reveal an evolutionary principle whereby protein oligomerization allows evolutionary change to accumulate away from a conserved binding pocket to allosterically alter specificity of ligand interaction. This principle also explains how another (p)ppGpp target GMK is variably regulated across species. Since most ligands bind near protein interfaces, we propose that this principle extends to many other protein-ligand interactions.

Cross-sectional association between non-soy legume consumption, serum uric acid and hyperuricemia: the PREDIMED-Plus study

PURPOSE

To assess the association between the consumption of non-soy legumes and different subtypes of non-soy legumes and serum uric acid (SUA) or hyperuricemia in elderly individuals with overweight or obesity and metabolic syndrome.

METHODS

A cross-sectional analysis was conducted in the framework of the PREDIMED-Plus study. We included 6329 participants with information on non-soy legume consumption and SUA levels. Non-soy legume consumption was estimated using a semi-quantitative food frequency questionnaire. Linear regression models and Cox regression models were used to assess the associations between tertiles of non-soy legume consumption, different subtypes of non-soy legume consumption and SUA levels or hyperuricemia prevalence, respectively.

RESULTS

Individuals in the highest tertile (T3) of total non-soy legume, lentil and pea consumption, had 0.14 mg/dL, 0.19 mg/dL and 0.12 mg/dL lower SUA levels, respectively, compared to those in the lowest tertile (T1), which was considered the reference one. Chickpea and dry bean consumption showed no association. In multivariable models, participants located in the top tertile of total non-soy legumes [prevalence ratio (PR): 0.89; 95% CI 0.82-0.97; p trend = 0.01, lentils (PR: 0.89; 95% CI 0.82-0.97; p trend = 0.01), dry beans (PR: 0.91; 95% C: 0.84-0.99; p trend = 0.03) and peas (PR: 0.89; 95% CI 0.82-0.97; p trend = 0.01)] presented a lower prevalence of hyperuricemia (vs. the bottom tertile). Chickpea consumption was not associated with hyperuricemia prevalence.

CONCLUSIONS

In this study of elderly subjects with metabolic syndrome, we observed that despite being a purine-rich food, non-soy legumes were inversely associated with SUA levels and hyperuricemia prevalence.

TRIAL REGISTRATION

ISRCTN89898870. Registration date: 24 July 2014.

Uric Acid and Plant-Based Nutrition

Plant-based diets (PBDs) are associated with decreased risk of morbidity and mortality associated with important noncommunicable chronic diseases. Similar to animal-based food sources (e.g., meat, fish, and animal visceral organs), some plant-based food sources (e.g., certain soy legume products, sea vegetables, and brassica vegetables) also contain a high purine load. Suboptimally designed PBDs might consequently be associated with increased uric acid levels and gout development. Here, we review the available data on this topic, with a great majority of studies showing reduced risk of hyperuricemia and gout with vegetarian (especially lacto-vegetarian) PBDs. Additionally, type of ingested purines, fiber, vitamin C, and certain lifestyle factors work in concordance to reduce uric acid generation in PBDs. Recent limited data show that even with an exclusive PBD, uric acid concentrations remain in the normal range in short- and long-term dieters. The reasonable consumption of plant foods with a higher purine content as a part of PBDs may therefore be safely tolerated in normouricemic individuals, but additional data is needed in hyperuricemic individuals, especially those with chronic kidney disease.

Important food sources of fructose-containing sugars and incident gout: a systematic review and meta-analysis of prospective cohort studies

OBJECTIVE

Sugar-sweetened beverages (SSBs) are associated with hyperuricaemia and gout. Whether other important food sources of fructose-containing sugars share this association is unclear.

DESIGN

To assess the relation of important food sources of fructose-containing sugars with incident gout and hyperuricaemia, we conducted a systematic review and meta-analysis of prospective cohort studies.

METHODS

We searched MEDLINE, Embase and the Cochrane Library (through 13 September 2017). We included prospective cohort studies that investigated the relationship between food sources of sugar and incident gout or hyperuricaemia. Two independent reviewers extracted relevant data and assessed the risk of bias. We pooled natural-log transformed risk ratios (RRs) using the generic inverse variance method with random effects model and expressed as RR with 95% confidence intervals (CIs). The overall certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

We identified three studies (1 54 289 participants, 1761 cases of gout), comparing the highest with the lowest level of exposure for SSBs, fruit juices and fruits. No reports were found reporting incident hyperuricaemia. Fruit juice and SSB intake showed an adverse association (fruit juice: RR=1.77, 95% CI 1.20 to 2.61; SSB: RR=2.08, 95% CI 1.40 to 3.08), when comparing the highest to lowest intake of the most adjusted models. There was no significant association between fruit intake and gout (RR 0.85, 95% CI 0.63 to 1.14). The strongest evidence was for the adverse association with SSB intake (moderate certainty), and the weakest evidence was for the adverse association with fruit juice intake (very low certainty) and lack of association with fruit intake (very low certainty).

CONCLUSION

There is an adverse association of SSB and fruit juice intake with incident gout, which does not appear to extend to fruit intake. Further research is needed to improve our estimates.

TRIAL REGISTRATION NUMBER

NCT02702375; Results.

Normative range of blood biochemical parameters in urban Indian school-going adolescents

Adolescence is the most critical phase of human growth that radically alters physiology of the body and wherein any inconsistency can lead to serious health consequences in adulthood. The timing and pace at which various developmental events occur during adolescence is highly diverse and thus results in a drastic change in blood biochemistry. Monitoring the physiological levels of various biochemical measures in ample number of individuals during adolescence can call up for an early intervention in managing metabolic diseases in adulthood. Today, only a couple of studies in different populations have investigated blood biochemistry in a small number of adolescents however, there is no comprehensive biochemical data available worldwide. In view, we performed a cross-sectional study in a sizeable group of 7,618 Indian adolescents (3,333 boys and 4,285 girls) aged between 11–17 years to inspect the distribution of values of common biochemical parameters that generally prevails during adolescence and we observed that various parameters considerably follow the reported values from different populations being 3.56–6.49mmol/L (fasting glucose), 10.60–199.48pmol/L (insulin), 0.21–3.22nmol/L (C–peptide), 3.85–6.25% (HbA₁c), 2.49–5.54mmol/L (total cholesterol), 1.16–3.69mmol/L (LDL), 0.78–1.85mmol/L (HDL), 0.33–2.24mmol/L (triglycerides), 3.56–11.45mmol/L (urea), 130.01–440.15μmol/L (uric acid) and 22.99–74.28μmol/L (creatinine). Barring LDL and triglycerides, all parameters differed significantly between boys and girls (p< 0.001). Highest difference was seen for uric acid (p = 1.3 x10^-187) followed by C–peptide (p = 6.6 x10^-89). Across all ages during adolescence, glycemic and nitrogen metabolites parameters varied markedly with gender. Amongst lipid parameters, only HDL levels were found to be significantly associated with gender following puberty (p< 0.001). All parameters except urea, differed considerably in obese and lean adolescents (p< 0.0001). The present study asserts that age, sex and BMI are the essential contributors to variability in blood biochemistry during adolescence. Our composite data on common blood biochemical measures will benefit future endeavors to define reference intervals in adolescents especially when the global availability is scarce.