Serum urate levels and consumption of common beverages and alcohol among Chinese in Singapore

Dose-Response Relationship Between Alcohol Consumption and Gout Risk: Do Subtypes of Alcoholic Beverages Make a Difference?

OBJECTIVE

Although previous studies have explored the association of drinking with gout risk, we sought to explore the dose-response relationship and the evidence between subtypes of alcoholic beverages and gout risk.

METHODS

The weekly alcoholic beverage consumption of patients in the UK Biobank was collected and calculated. The Cox regression model was applied to assess the effects of drinking alcohol in general and its subtypes on gout risk by calculating the hazard ratio (HR) and 95% CIs. Additionally, the restricted cubic splines were used to estimate the dose-response relationship between alcohol consumption and gout risk. To evaluate the robustness, we performed subgroup analysis across various demographic characteristics.

RESULTS

During a mean follow-up period of 11.7 years, a total of 5728 new incident gout cases were diagnosed among 331,865 participants. We found that light alcohol consumption was linked to a slight decrease in gout incidence among female individuals (HR 0.78, 95% CI 0.65-0.94, P = 0.01), whereas there was no significant association in male individuals. Moreover, the dose-response relationship showed that drinking light red wine and fortified wine could reduce the gout risk, whereas beer or cider, champagne or white wine, and spirits increased the gout risk at any dose.

CONCLUSION

Our study suggested a J-shaped dose-response relationship between drinking and gout risk in female individuals, but not in male individuals. For specific alcoholic beverages, light consumption of red wine and fortified wine was associated with reduced gout risk. These findings offer new insights into the roles of alcoholic beverages in gout incidence risk, although further validation is warranted.

Changes in alcohol intake and serum urate changes: longitudinal analyses of annual medical examination database

INTRODUCTION

Despite the established cross-sectional association between alcohol intake and serum urate (SU), its longitudinal association remains unknown. This study aimed to determine whether changes in alcohol intake have a clinically relevant association with SU change.

METHOD

We conducted retrospective analyses using systematically collected annual medical examination data from October 2012 to October 2022 in a Japanese preventive medicine centre. The exposure was changes in alcohol intake between two consecutive visits. The association of SU changes with alcohol intake changes was estimated by mixed-effect linear regression with adjustment for relevant covariates.

RESULTS

We analysed 63 486 participants (median age, 47.0 years; 55% women; 58.6% regular alcohol drinkers with a median of 1.4 drinks/day) with 370 572 visits. The median SU level was 5.3 mg/dL, and 506 (0.8%) participants had diagnoses of gout or hyperuricemia without medication use during the study period. Decreasing one daily alcohol intake had a clinically small association with SU changes (-0.019 (95% CI: -0.021 to -0.017) mg/dL). Beer had the largest association with SU (-0.036 (95% CI: -0.039 to -0.032) mg/dL for one beer decrease). Complete discontinuation of any alcohol from a mean of 0.8 drinks/day was associated with -0.056 mg/dL (95% CI: -0.068 to -0.043) decrease in SU; the association became larger in hyperuricemic participants (-0.110 mg/dL (95% CI: -0.154 to -0.066) for alcohol discontinuation from a mean of 1.0 drinks/day).

CONCLUSIONS

This study revealed changes in alcohol intake had small associations with SU change at the general Japanese population level. Complete discontinuation of alcohol in hyperuricemic participants had only modest improvement in SU.

Interaction of genetic variation at ADH1B and MLXIPL with alcohol consumption for elevated serum urate level and gout among people of European ethnicity

BACKGROUND

Alcohol consumption is a risk factor for hyperuricaemia and gout. Multiple single-nucleotide polymorphisms (SNPs) have been identified as associated with both alcohol consumption and serum urate or gout in separate genome-wide association studies (GWAS). This study aimed to identify and characterise interactions between these shared signals of genetic association and alcohol consumption for serum urate level, hyperuricaemia, and gout.

METHODS

This research was conducted using the UK Biobank resource. The association of alcohol consumption with serum urate and gout was tested among 458,405 European participants. Candidate SNPs were identified by comparing serum urate, gout, and alcohol consumption GWAS for shared signals of association. Multivariable-adjusted linear and logistic regression analyses were conducted with the inclusion of interaction terms to identify SNP-alcohol consumption interactions for association with serum urate level, hyperuricaemia, and gout. The nature of these interactions was characterised using genotype-stratified association analyses.

RESULTS

Alcohol consumption was associated with elevated serum urate and gout. For serum urate level, non-additive interactions were identified between alcohol consumption and rs1229984 at the ADH1B locus (P = 3.0 × 10-44) and rs6460047 at the MLXIPL locus (P = 1.4 × 10-4). ADH1B also demonstrated interaction with alcohol consumption for hyperuricaemia (P = 7.9 × 10-13) and gout (P = 8.2 × 10-9). Beer intake had the most significant interaction with ADH1B for association with serum urate and gout among men, while wine intake had the most significant interaction among women. In the genotype-stratified association analyses, ADH1B and MLXIPL were associated with serum urate level and ADH1B was associated with hyperuricaemia and gout among consumers of alcohol but not non-consumers.

CONCLUSIONS

In this large study of European participants, novel interactions with alcohol consumption were identified at ADH1B and MLXIPL for association with serum urate level and at ADH1B for association with hyperuricaemia and gout. The association of ADH1B with serum urate and gout may occur through the modulation of alcohol metabolism rate among consumers of alcohol.

Effect of tea intake on genetic predisposition to gout and uric acid: a Mendelian randomization study

Objective

The effect of tea on gout and uric acid is still controversial. This study aims to analyze the effect of tea intake on genetic predisposition to gout, idiopathic gout, gout due to impairment of renal function as well as uric acid by Mendelian randomization (MR).

Methods

Forty independent single nucleotide polymorphisms (SNPs) associated with tea intake were selected from UK Biobank. SNPs for uric acid were obtained from BioBank Japan, SNPs for gout were obtained from UK Biobank, and SNPs for gout due to impairment of renal function and idiopathic gout were derived from FinnGen. The causal relationship of exposure-outcome was tested using inverse variance weighted, MR-Egger and weighted median. MR-Egger intercept was employed to assess horizontal pleiotropy, Cochran's Q test was used to assess heterogeneity, and leave-one-out sensitivity analysis was utilized to analyze the stability of the results.

Results

The results of MR analysis showed that tea intake was negatively associated with gout due to impairment of renal function (OR 0.997, 95% CI 0.994 to 0.999, P = 0.017), whereas there was no causal association with gout, idiopathic gout, and uric acid (P > 0.05), for which sensitivity analysis suggested that these results were robust.

Conclusions

There was a genetic predisposition effect of increased tea intake on the reduced risk of gout due to impairment of renal function, whereas there was no such effect on gout, idiopathic gout, and uric acid. Tea intake may become an important option in the dietary treatment of gout due to impairment of renal function.

Causal Association Between Tea Consumption and Gout: A Mendelian Randomization Study

OBJECTIVE

Evidence from prospective studies on the consumption of tea and risk of gout is conflicting and limited. We aimed to investigate the potential causal effects of tea intake on gout using Mendelian randomization (MR).

METHODS

Genome-wide association studies in UK Biobank included 349 376 individuals and successfully discovered single-nucleotide polymorphisms linked to consumption of one cup of tea per day. Summary statistics from the Chronic Kidney Disease Genetics consortium included 13 179 cases and 750 634 controls for gout. Two-sample MR analyses were used to evaluate the relationship between tea consumption and gout risk. The inverse-variance weighted (IVW) method was used for primary analysis, and sensitivity analyses were also conducted to validate the potential causal effect.

RESULTS

In this study, the genetically predicted increase in tea consumption per cup was associated with a lower risk of gout in the IVW method (OR: 0.90; 95% CI: 0.82-0.98). Similar results were found in weighted median methods (OR: 0.88; 95% CI: 0.78-1.00), while no significant associations were found in MR-Egger (OR: 0.89; 95% CI: 0.71-1.11), weighted mode (OR: 0.80; 95% CI: 0.65-0.99), and simple mode (OR: 1.01; 95% CI: 0.75-1.36). In addition, no evidence of pleiotropy was detected by MR-Egger regression (P=0.95) or MR-PRESSO analysis (P=0.07).

CONCLUSION

This study provides evidence for the daily consumption of an extra cup of tea to reduce the risk of gout.

Potential role of tea drinking in preventing hyperuricaemia in rats: biochemical and molecular evidence

BACKGROUND

Lifestyle and diet play a significant role in hyperuricaemia. Accumulating evidence indicates that tea consumption is associated with hyperuricaemia and gout. However, diverse compounds in different types of tea make it quite difficult to determine the relevant molecular mechanism. Here, we compared the effects of six types of tea on hyperuricaemia induced by potassium oxonate (PO) and hypoxanthine in rats and investigated the possible underlying mechanisms.

METHODS

Rats were randomly assigned to ten groups: the control, hyperuricaemia model, benzbromarone positive control, traditional Chinese medicine Simiao San positive control, green tea, yellow tea, black tea, white tea, red tea, and cyan tea treatment groups. After 21 days, uric acid (UA), xanthine oxidase (XOD), alanine aminotransferase (ALT),blood urea nitrogen (BUN), and creatinine (CRE) were assessed. Serum levels of interleukin-1β (IL-1β) were measured with an enzyme-linked immunosorbent assay. Haematoxylin-eosin staining and immunohistochemistry were used to assess liver and kidney injury.

RESULTS

The levels of UA, CRE, and BUN in the treatment group were decreased to varying degrees. There was a significant reduction in UA, CRE, and BUN levels for yellow tea compared to the positive control drugs. Yellow tea suppressed XOD activity and alleviated hepatic and kidney injury. Network pharmacology and untargeted metabolomics indicated that ten yellow tea bioactive ingredients and 35 targets were responsible for preventing hyperuricaemia, which was mediated by 94 signalling pathways, including IL-1β and TNF.

CONCLUSION

These findings indicate that green tea cannot reduce the serum uric acid level of hyperuricaemic rats. Yellow tea can significantly improve hyperuricaemia by regulating the inflammatory response, autophagy, and apoptosis. This study provides a potential candidate for the treatment of hyperuricaemia and a basis for selecting therapeutic tea for patients with hyperuricaemia.

Changes in the prevalence of hyperuricemia in clients of health examination in Eastern China, 2009 to 2019

BACKGROUND

With the continuous improvement of people's living standards, the incidence of hyperuricemia (HUA) is increasing globally. The prevalence of HUA ranged in terms of region, race, and age. This study aims to investigate the changes in the prevalence of HUA in clients of health examination in Eastern China between 2009 and 2019.

METHODS

Chinese men and women aged 20-79 years (n = 4847 in the 2009 group and n = 12,188 in 2019 group) who had received health examinations were enrolled. Serum uric acid (UA) levels and biochemical parameters, including fasting blood-glucose (FBG), triglyceride (TG), total cholesterol (CHOL), high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine (Cr) and blood urea nitrogen (BUN) were evaluated. The prevalence of HUA in different age groups were measured, and the correlation of biochemical parameters with HUA were analyzed.

RESULTS

The prevalence of HUA was 18.7% in the 2019 group, which was significantly higher than that in 2009 (11.1%). In females, the prevalence of HUA was significantly higher in 2019 than 2009 for age groups of 20-29 and 30-39 years. In male population, 2019 participants had significantly higher age-specific prevalence for all age groups than 2009 participants. Young men aged 20-29 years became the main population of HUA in the 2019 participants, whereas middle-aged men aged 40-49 years had the highest prevalence of HUA in the 2009 participants. The prevalence rates of HUA in all BMI groups in 2019 participants were significantly higher than those in 2009 participants. Spearmen's correlation analysis and Logistic regression analysis indicated that BMI was positively correlated with HUA. The receiver-operating characteristic curve (ROC) analysis showed BMI > 24.48 kg/m2 and BMI > 23.84 kg/m2 displayed good capacities to discriminate the population with HUA from those without HUA in 2009 and 2019 participants, respectively.

CONCLUSIONS

In recent 10 years, the prevalence of HUA was increased rapidly in Chinese adults, especially in males. In 2019, the young male group (20-29 years old) replaced the middle-aged male group (40-49 years old) in 2009 as the leading age group for male HUA. BMI was positively correlated with HUA, and might be a potential risk factors to predict HUA.

Sugar-Sweeten Beverage Consumption Is Associated With More Obesity and Higher Serum Uric Acid in Chinese Male Gout Patients With Early Onset

Background

Early onset gout has received increasing interest from researchers. Previous studies have reported that serum urate (sUA) levels and prevalence of obesity are higher in early onset gout patients than in later-onset gout patients. We explored the dietary habits of early onset and later-onset gout patients and their association with clinical features.

Materials and Methods

Gout patients completed a 10-item food frequency questionnaire. Early onset gout patients were defined as gout onset before the age of 40, and onset after age 40 was classified as later-onset. Associations between dietary factors, obesity, and sUA level of ≥600 μmol/L were assessed using logistic regression.

Results

Among the 655 gout patients, 94.6% were males, and 59.1% presented with early onset gout. All early onset patients were males. sUA level was significantly higher in the early onset group than in the later-onset group (550.7 vs. 513.4 μmol/L). The proportion of patients with a sUA level of ≥ 600 μmol/L (40.3 vs. 26.2%) and obesity (27.6 vs. 10.7%) was higher in the early onset group than in the later-onset group (all p < 0.05). The early onset group consumed more red meat (101–200 g/day: 43.6 vs. 26.0%), sugar-sweetened beverages (>4 times/week: 27.9 vs. 7.7%), and milk and milk products (1–2 times/week: 28.5 vs. 16.6%), but less alcohol (>84 g/day: 8.5 vs. 21.5%) and tea (>4 times/week: 35.7 vs. 52.4%; all p < 0.05). Sugar-sweetened beverage intake was positively correlated with sUA level of ≥600 μmol/L (compared with <once/week [reference], >4 times/week: adjusted odds ratio = 2.2, 95% confidence interval: 1.4, 3.7) and obesity (compared with <once/week [reference], >4 times/week: adjusted odds ratio = 2.2, 95% confidence interval: 1.2, 3.7). These correlations remained significant for early onset gout patients.

Conclusion

Sugar-sweetened beverage intake replaced alcohol as the main dietary risk factor for gout in early onset patients, and this change was associated with a greater prevalence of obesity and higher sUA level. Clinicians should provide specific dietary education for different generations of gout patients. The epidemic of sugar-sweetened beverage consumption should be considered for the development of public health policies for the prevention of gout.

Tea Consumption is Associated with an Increased Risk of Hyperuricemia in an Occupational Population in Guangdong, China

Purpose

Chronic hyperuricemia leads to long-term deposition of monosodium urate crystals that may damage the joint structure and affect quality of life. Although hyperuricemia prevalence varies, most studies indicate increased cases of hyperuricemia worldwide. The relationship between hyperuricemia and tea consumption is uncertain. This cross-sectional study investigated the effect of tea consumption on the risk of hyperuricemia in the working population in Guangdong, China.

Patients and Methods

Data on weight, height, blood pressure, laboratory test results, and health questionnaire responses of 7644 adults aged ≥18 years were obtained from the health examinee dataset of Nanfang Hospital. The characteristics of subjects with and without hyperuricemia were compared using t-tests or non-parametric Mann–Whitney U-tests for continuous variables and chi-square tests for categorical variables. Relationships between hyperuricemia and participant characteristics (sex, age, education level, smoking history, alcohol consumption, hypertension, body mass index, tea consumption, and other dietary factors) were examined using univariate and multivariate logistic regression models to identify independent risk factors for hyperuricemia.

Results

Tea consumption was associated with a higher risk of hyperuricemia in the crude model (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.48–2.05, once a month through twice a week vs never, P<0.001; OR 2.44, 95% CI 2.07–2.89, ≥3 times a week vs never, P<0.001). The adjusted OR for hyperuricemia was 1.30 (95% CI 1.08–1.56, P=0.006) in participants who consumed tea once a month through twice a week and 1.35 (95% CI 1.11–1.64, P=0.003) in those who consumed tea ≥3 times a week compared with the “never” reference group after adjusting for sociodemographic factors, anthropometric and biochemical indices, and dietary factors. This relationship remained significant in men but not women in subgroup analysis.

Conclusion

Tea consumption is an independent risk factor for hyperuricemia and is more pronounced in men than women.

The Inverted U-Shaped Association of Caffeine Intake with Serum Uric Acid in U.S. Adults

BACKGROUND AND AIMS

Caffeine is a worldwide popularly consumed constituent in foods that can exert physiological effects. However, previous researches about the relationship between caffeine intake and serum uric acid (SUA) were limited and controversial. Therefore, we sought to investigate that relationship in U.S. adults.

METHODS

In this cross-sectional study, the total sample of 7888 selected participants (3838 males and 4050 females) were identified from the National Health and Nutritional Examination Surveys (NHANES) 2015-2018. All subjects were tested for serum uric acid levels (μmmol/L), and their daily caffeine intakes (mg/d) were obtained by an average of two 24-hour dietary recalls. Multivariate linear regression models were used to evaluate the association between two variables in total subjects and subgroup analyses. Generalized additive models with smooth curve fittings were also performed.

RESULTS

Multivariate regression analyses showed caffeine intake was negatively correlated with SUA after adjustment of other confounders. The subgroup analyses stratified by gender showed the negative correlation of caffeine intake with SUA was statistically significant in males but not in females. Furthermore, we observed a nonlinear inverse association of caffeine intake with SUA (P nonlinear <0.001) in the generalized additive model, followed by an inverted U-shaped curve (inflection point: 60.5mg/d) for all participants. This inverted U-shaped relationship between them could also be found in both genders, individuals aged below 60 years old, overweight (BMI of 25 to 30), and Non-Hispanic White individuals.

CONCLUSIONS

This study indicated that caffeine intake exhibited an inverse correlation with SUA, especially in males. In addition, this inverse relationship was nonlinear, which followed an inverted U-shaped curve.

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.

Tea consumption and serum uric acid levels among older adults in three large-scale population-based studies in China

Background and aims

The association between serum uric acid (SUA) and tea consumption has been studied in previous work, and there were arguments among various population group employed as well as different statistical approaches. The aim of this work is to investigate the tea effect on SUA levels among older adults by comparing three large-scale populations with both cross-sectional and longitudinal analyses.

Method

We examined the relationship between intake and SUA levels among older adults using linear regression. All the studies include the parameters SUA levels, tea intake, age, sex, education level, smoking status, alcohol drinking status, body mass index (BMI), and health history (diabetes, hypertension, and fasting plasma glucose). The cross-sectional analyses were conducted with 4579 older adults in the Weitang Geriatric Diseases Study (WGDS, ≥60 years), 2440 in the China Health and Nutrition Survey (CHNS, ≥60 years) and 1236 in the Chinese Longitudinal Healthy Longevity Survey (CLHLS, ≥62 years); and the longitudinal analyses were performed with 3870 (84.5%) in the WGDS and 420 (34.0%) in the CLHLS. Multivariable linear regression analyses were performed in both cross-sectional and longitudinal studies.

Results

Cross-sectional studies showed that tea consumers tended to have higher SUA levels than non-tea consumers in all the three datasets (P < 0.05). However, longitudinal associations of SUA levels with tea consumption had no statistical significance (P>0.05). The results of sex-stratified analyses were consistent with those of the whole datasets.

Conclusions

This work implied that any possible association between tea consumption and SUA levels could be very weak.

Dietary Antioxidant Supplements and Uric Acid in Chronic Kidney Disease: A Review

Increased serum levels of uric acid have been associated with the onset and development of chronic kidney disease (CKD), cardiovascular disease, and mortality, through several molecular pathogenetic mechanisms, such as inflammation and oxidative stress. Oxidative stress is present even in the early stages of CKD, progresses parallelly with the deterioration of kidney function, and is even more exacerbated in end-stage renal disease patients undergoing maintenance hemodialysis. Although acting in the plasma as an antioxidant, once uric acid enters the intracellular environment; it behaves as a powerful pro-oxidant. Exogenous intake of antioxidants has been repeatedly shown to prevent inflammation, atherosclerosis and oxidative stress in CKD patients. Moreover, certain antioxidants have been proposed to exert uric acid-lowering properties. This review aims to present the available data regarding the effects of antioxidant supplements on both oxidative stress and uric acid serum levels, in a population particularly susceptible to oxidative damage such as CKD patients.

Using marginal standardisation to estimate relative risk without dichotomising continuous outcomes

Background

Although criticisms regarding the dichotomisation of continuous variables are well known, applying logit model to dichotomised outcomes is the convention because the odds ratios are easily obtained and they approximate the relative risks (RRs) for rare events.

Methods

To avoid dichotomisation when estimating RR, the marginal standardisation method that transforms estimates from logit or probit model to RR estimate is extended to include estimates from linear model in the transformation. We conducted a simulation study to compare the statistical properties of the estimates from: (i) marginal standardisation method between models for continuous (i.e., linear model) and dichotomised outcomes (i.e., logit or probit model), and (ii) marginal standardisation method and distributional approach (i.e., marginal mean method) applied to linear model. We also compared the diagnostic test for probit, logit and linear models. For the real dataset analysis, we applied these analytical approaches to assess the management of inpatient hyperglycaemia in a pilot intervention study.

Results

Although the RR estimates from the marginal standardisation method were generally unbiased for all models in the simulation study, the marginal standardisation method for linear model provided estimates with higher precision and power than logit or probit model, especially when the baseline risks were at the extremes. When comparing approaches that avoid dichotomisation, RR estimates from these approaches had comparable performance. Assessing the assumption of error distribution was less powerful for logit or probit model via link test when compared with diagnostic test for linear model. After accounting for multiple thresholds representing varying levels of severity in hyperglycaemia, marginal standardisation method for linear model provided stronger evidence of reduced hyperglycaemia risk after intervention in the real dataset analysis although the RR estimates were similar across various approaches.

Conclusions

When compared with approaches that do not avoid dichotomisation, the RR estimated from linear model is more precise and powerful, and the diagnostic test from linear model is more powerful in detecting mis-specified error distributional assumption than the diagnostic test from logit or probit model. Our work describes and assesses the methods available to analyse data involving studies of continuous outcomes with binary representations.

Electronic supplementary material

The online version of this article (10.1186/s12874-019-0778-9) contains supplementary material, which is available to authorized users.

Sweetened Beverages Consumption and Pancreatic Cancer: A Meta-Analysis

No study has summarized earlier findings on the association of sweetened beverages (SBs) consumption and risk of Pancreatic Cancer (PC). This systematic review and meta-analysis was conducted to systematically review available observational studies that examined the association of SB consumption with risk of PC. Relevant papers published up to December 2017 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar databases, using relevant keywords. Cohort and case-control studies that examined the association of SB with PC in adults were included. Overall, 5 cohort studies with 2,041,689 participants (58.68% female, 41.32% male) and 4 case-control studies [enrolled 1,496 cases with PC (55.82% male, 44.18% female) and 3,179 controls (53.32% male, 46.68% female)] were included. Combining effect sizes from cohort studies, we found no significant association between SB consumption and risk of PC (RR: 1.06; 95% CI: 0.87-1.29). Although, stratification by the study location, follow-up duration, exposure and outcome assessment method, and adjustment for physical activity and race/ethnicity removed between-study heterogeneity, it did not affect the association. We found that 50 g/d increment in SB consumption was not linearly associated with risk of PC (RR: 1.00, 95% CI: 0.96, 1.04). No significant nonlinear association was also reached (P-nonlinearity = 0.13). In addition, pooling effect sizes from case-control studies, we did not find significant association between SB consumption and risk of PC (RR: 1.11; 95% CI: 0.92-1.35). We did not find any significant association between SB consumption and risk of PC. Additional studies are required to shed light on this issue.

Consumption of sugar sweetened beverages and dietary fructose in relation to risk of gout and hyperuricemia: a systematic review and meta-analysis

Background: Findings on the association of sugar sweetened beverages (SSB) and fructose intakes with gout and hyperuricemia have been conflicting.Objective: We aimed to perform a systematic review and meta-analysis on studies that examined the association of SSB and fructose consumption with gout and hyperuricemia in adults.Methods: We searched PubMed, Scopus and Google Scholar up to Aug 2017 for all relevant published papers assessing SSB and fructose intakes and risk of gout and hyperuricemia. After excluding non-relevant papers, 10 studies remained in our systematic. Meta-analysis on SSB consumption and risk of gout was done on three effect sizes from cohort studies and five effect sizes from case-control studies. For risk of hyperuricemia, the meta-analysis was done on six effect sizes from cross-sectional studies. All analyses were performed on ORs or RRs.Results: We found an overall significant positive association between SSB consumption and risk of gout in both cohort (summary effect size: 1.35; 95% CI: 1.18-1.55) and case-control studies (summary effect size: 1.33; 95% CI: 1.06-1.66). Meta-analysis on cross-sectional studies revealed that SSB consumption was associated with 35% greater odds of hyperuricemia (summary effect size: 1.35; 95% CI: 1.19-1.52). No evidence of between-study heterogeneity as well as publication bias was found. Although the studies on fructose intake and risk of gout and hyperuricemia were included in our systematic review, we did not perform met-analysis on these studies due to insufficient number of publications.Conclusion: We found that SSB consumption was significantly associated with increased risk of gout and hyperuricemia in adult population. Further studies are needed to examine the association between dietary fructose intake and risk of gout and hyepruricemia.

Review Article: URIC ACID HOMEOSTASIS AND DISTURBANCES

This review examined the homeostasis of uric acid in human body and analyzed recent studies of the affecting major variables. Normal uric acid concentration in male is 3.5-7.2 mg/dL and in female is 2.6-6 mg/dL. Daily turnover of normal uric acid ranges from 498-1392 mg/day, miscible pool is 767-1650 mg, reabsorption is 8064 mg/day, renal excretion is 262-620 mg/day and intestine 186-313 mg/day. The dynamics of uric acid is influenced by factors of food, drink, age, history of disease, and genetic. High purine dietary consumption increases blood uric acid by 1-2 mg/dL, 213-290 g/day fructose drinks increases 0.52-1.7 mg/dL, 1.5 g/kgBW sucrose increases 0.61 mg/dL, and 10-20 ml/kgBW beer increases 0.50-0.92 mg/dL. The ABCG2 gene plays a role in bringing uric acid out of the body by 114.31-162.73 mg/dL, SLC2A9 of 5.43-20.17 mg/dL, and SLC22A12 of 5.77-6.71 mg/dL. The data described the homeostasis of uric acid and the magnitude of the impact of environmental (consumption of food, beverages, and lifestyle) and genetic factors. Understanding uric acid homeostasis and its disturbances is important in managing diseases as a consequence of hyperuricemia and hypouryscemia

Is tea consumption associated with the serum uric acid level, hyperuricemia or the risk of gout? A systematic review and meta-analysis

Background

The aim of this study was to examine the associations of tea consumption with the serum uric acid (SUA) level, hyperuricemia (HU) and the risk of gout.

Methods

A comprehensive literature search up to June 2016, using PUBMED and EMBASE databases, was conducted to identify the relevant observational studies that examined the associations of tea consumption with the SUA level, HU and the risk of gout.

Results

A total of fifteen observational studies were included in this study, and nine studies were extracted for meta-analysis. For the SUA level, seven studies were included. According to the combined weighted mean difference (WMD), there was no significant difference between the highest and the lowest tea intake category in terms of the SUA level (WMD = 7.41 μmol/L, 95%CI: −2.34 to 17.15; P = 0.136). In subgroup analysis including three studies, green tea consumption was positively associated with the SUA level (WMD = 17.20 μmol/L, 95%CI: 7.00 to 27.40; P = 0.01). For the prevalence of HU, five studies were included. The overall multi-variable adjusted odds ratio (OR) for the highest versus the lowest category of tea consumption was 0.98 (95%CI: 0.77 to 1.24; P = 0.839). For the risk of gout, two prospective cohort studies showed that there was no relationship between tea consumption and the risk of gout in males and females, respectively.

Conclusion

The current evidences suggest that tea consumption does not seem to be associated with the SUA level, HU and the risk of gout. However, due to the limited number of studies, green tea consumption might be positively associated with the SUA level. More well-designed prospective cohort studies are needed to elaborate these issues further.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1456-x) contains supplementary material, which is available to authorized users.

Benchmark dose of alcohol consumption for development of hyperuricemia in Japanese male workers: An 8-year cohort study

BACKGROUND

To estimate the benchmark dose (BMD) and their 95% lower confidence limits (BMDL) of alcohol consumption as the reference level for the development of hyperuricemia based on the dose-response relationship.

METHODS

An 8-year prospective cohort study was conducted in 8097 male workers at a Japanese steel company who received annual health check-ups between 2002 and 2009. The endpoints for development of hyperuricemia were defined as a uric acid ≥7 mg/dL or taking any anti-hyperuricemic medication. The dose-response relationship of alcohol consumption was investigated using multivariate-pooled logistic regression analyses adjusted for other potential covariates. We estimated the BMD and BMDL of alcohol consumption for the development of hyperuricemia, using the parameters obtained by pooled logistic regression with a benchmark response (BMR) of 5% or 10%.

RESULTS

Mean observed years per person was 3.86 years. The incidence rate per 1000 person-years was 61.1. The odds ratio calculated for the development of hyperuricemia was 1.29 [95% confidence interval, (1.22-1.36)] with an increase in alcohol consumption per 1 gou/day (1 gou/day = alcohol 22 g/day). The estimated BMDL/BMD with a BMR of 5% was 2.5/2.8 gou/day (54.5/61.8 g/day) and with a BMR of 10% was 4.0/4.6 gou/day (88.9/100.9 g/day).

CONCLUSIONS

The present study showed that alcohol consumption of 2.5 gou/day (=ethanol 55 g/day) caused a distinct increase in the risk of hyperuricemia. Valuable information for preventing alcohol-induced hyperuricemia was obtained by a long-term follow-up study of a large cohort.

Is coffee consumption associated with a lower risk of hyperuricaemia or gout? A systematic review and meta-analysis

OBJECTIVES

To examine the associations of coffee consumption with the serum uric acid (SUA) level, hyperuricaemia (HU) and gout.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

A comprehensive literature search up to April 2015, using PubMed and EMBASE databases, was conducted to identify the observational researches that examined the associations of coffee consumption with the SUA level, HU and gout. The standard mean difference (SMD), OR, relative risk (RR) and their corresponding 95% CIs for the highest and the lowest categories of coffee intake were determined.

RESULTS

A total of 11 observational studies (6 cross-sectional, 3 cohort and 2 case-control studies) were included in this systematic review and meta-analysis. The combined SMD suggested that there was no significant difference between the highest and the lowest coffee intake categories in terms of the SUA level (SMD=-0.09, 95% CI -0.23 to 0.05; p=0.21). Meanwhile, the overall multivariable adjusted OR for HU showed no significant difference between the highest and the lowest coffee intake categories (OR=0.84, 95% CI 0.65 to 1.09; p=0.20). However, the overall multivariable adjusted RR for gout showed a significant inverse association between coffee consumption and the incidence of gout (RR=0.43, 95% CI 0.31 to 0.59, p<0.001).

CONCLUSIONS

Current evidences are insufficient to validate the association between coffee consumption and a lower risk of HU. Owing to the limited number of studies, the available data show that coffee consumption may be associated with a lower risk of incident gout. Further well-designed prospective researches and randomised controlled trials are therefore needed to elaborate on these issues.

The association of vitamin C, alcohol, coffee, tea, milk and yogurt with uric acid and gout

About 2500 years ago, gout was observed by Hippocrates and many people suffered severe pain and deformity. Lifestyle and diet play a significant role in gout and serum uric acid levels. Epidemiological and research studies have supported this evidence. Many recommendations and guidelines from different parts of the world mention the impact of diet on gout. Recently, new research has shown associations between vitamin C, alcohol, coffee, tea, milk and yogurt with uric acid and the risk of gout. Our review summarizes recently published research regarding dietary impact on the risk of gout and serum uric acid levels.

Metabolically healthy obesity also has risk for hyperuricemia among Chinese general population: A cross-sectional study

INTRODUCTION

The metabolically healthy obese (MHO) refers to obese individuals with a favorable metabolic profile. It is unknown whether metabolically healthy status in persons with obesity or overweight decreases the risk of hyperuricemia. This study aims to explore the association of MHO with risk of hyperuricemia.

METHODS

We performed a cross-sectional study including 11,435 (5300 men and 6135 women) general population aged ≥35 years in Liaoning Province. Anthropometric measurements, laboratory examinations and self-reported information on lifestyle factors were collected by trained personnel. Metabolically healthy overweight/obesity was defined according to body mass index and ATP-III criterion of metabolically healthy status. Hyperuricemia was defined as SUA ≥7mg/dl (420mmol/L) in men or ≥6mg/dl (360mmol/L) in women. Logistic regression analyses were performed to explore the association between overweight/obesity with different metabolic status and risk of hyperuricemia.

RESULTS

Among total subjects, 470 (4.2%) were metabolically healthy obese (MHO) and 1567 (14.0%) were metabolically unhealthy obese (MUO). For metabolically healthy female participants, the prevalence of hyperuricemia with overweight was similar to with a normal BMI (2.5% vs. 3.1%, P=0.314). Multivariate logistic regression analyses showed that MHO (OR=2.48, 95% CI: 1.81-3.41) and MUO (OR=4.81, 95% CI: 3.97-5.83) were significantly associated with hyperuricemia. However, the odds ratio in females with metabolically healthy overweight was 0.85 (95% CI: 0.53-1.37).

CONCLUSIONS

Metabolically healthy might decline the risk of hyperuricemia, but overweight and obesity with metabolically healthy had also strong associations with hyperuricemia, except in females with metabolically healthy overweight.

Effects of coffee consumption on serum uric acid: systematic review and meta-analysis

OBJECTIVE

Study results on the effects of coffee consumption on serum uric acid (UA) have been conflicting. The aim of this study is to analyze the literature regarding the effect of coffee consumption on serum UA.

METHODS

We searched MEDLINE, EMBASE, the Cochrane library, and KoreaMed for all articles published before January 2015. Studies with quantitative data on coffee consumption and serum UA level were included. Coffee consumption and serum UA level were identified with/without the risk of gout.

RESULTS

Nine studies published between 1999 and 2014 were included, containing a total of 175,310 subjects. Meta-analysis demonstrated that coffee has a significantly lowering effect on serum UA, where there are gender differences in the amount of coffee required to lower serum UA. Women (4-6 cups/day) need more coffee to lower serum UA than men (1-3 cups/day). Meta-analysis showed that coffee intake of 1 cup/day or more was significantly associated with reduction of the risk of gout, with a negative correlation with the amount of daily coffee intake for both genders.

CONCLUSIONS

This is the first systematic review on the effects of coffee consumption on serum UA. Based on our study, moderate coffee intake might be advocated for primary prevention of hyperuricemia and gout in both genders.

The effect of coffee, tea, and caffeine consumption on serum uric acid and the risk of hyperuricemia in Korean Multi-Rural Communities Cohort

Caffeine, a commonly consumed food constituent, is known to exert beneficial physiological effects in humans. There is a lack of comprehensive population data for the effects of caffeine intake on urate metabolism. Therefore, the aim of this study was to determine whether coffee, tea, and caffeine intake influences serum uric acid and the risk of hyperuricemia in the Korean Multi-Rural Communities Cohort. We enrolled 9,400 participants in this study. An assessment of various dietary intake amounts of substances such as coffee and tea was performed using a food frequency questionnaire. The content of caffeine was calculated from coffee (74 mg/cup) and tea (15 mg/cup) intake information from the past year. Multivariate logistic regression models, multiple linear regression models, and analysis of covariance were applied to identify any association of dietary intake with serum uric acid levels or the risk of hyperuricemia. No trends for coffee, tea, or caffeine intake were found according to each quintile with serum uric acid in males, although there were weak, marginally significant trends between the content of coffee and caffeine intake and serum uric acid level in females (p = 0.07 for both). Tea intake in males and caffeine intake in females were significantly different between non-hyperuricemia and hyperuricemia (p = 0.04 and p = 0.04, respectively). In addition, a significant association of serum uric acid level with tea intake in males (β = 0.0006, p = 0.02) and with tea intake and caffeine intake in females (β = 0.0003, p = 0.04 and β = 0.0006, p = 0.02, respectively) was observed. There was no effect of coffee, tea, or caffeine intake on the risk of hyperuricemia in either males or females. This study suggests that caffeine consumption might have an effect on serum uric acid in females. However, coffee, tea, and caffeine intake amounts were not associated with the risk of hyperuricemia.

Allopurinol as a kidney-protective, cardioprotective, and antihypertensive agent: hype or reality?

Numerous experimental and clinical studies suggest that uric acid might have pathobiologic implications in the development and progression of hypertension, kidney disease, and coronary heart disease, among others, resulting in renewed interest in uric acid as a potential pathogenic mediator in these clinical conditions. Despite encouraging animal studies showing beneficial roles of allopurinol, clinical studies and randomized controlled trials remain scarce, and, despite available clinical evidence supporting a therapeutic role for allopurinol, multiple issues remain before routine use of allopurinol can be recommended for use in patients with hyperuricemia and hypertension, kidney disease, or coronary heart disease. These include a need for more robust clinical trial data that evaluate efficacy on hard clinical outcomes, optimal dose, duration of treatment, and the potential for serious allergic reactions. In this article we review the current available evidence describing the effects of allopurinol in hypertension, kidney disease, and coronary heart disease, highlighting unresolved issues surrounding allopurinol use for uric acid lowering in individuals without gout.