The role of hyperuricemia in vascular disorders

Optimizing gout treatment: A comprehensive review of current and emerging uricosurics

Gout is the most common inflammatory arthritis, affecting approximately 5.1% of adults in the United States (US) population. Gout is a metabolic and autoinflammatory disease. Elevated uric acid pools lead to the precipitation of monosodium urate (MSU) crystals in and around joints, as well as other tissues, and the subsequent autoinflammatory response. Since elevated serum urate (SU) levels (hyperuricemia) correspond with gout severity, urate-lowering therapies (ULTs) are the cornerstone of gout treatment. ULTs include xanthine oxidoreductase inhibitors, uricosurics, less commonly used in the US but widely used in Europe and Asia, including benzbromarone, dotinurad, and probenecid (the only US Food and Drug Administration (FDA) approved uricosuric in the US), and uricases, including rasburicase and pegloticase (available only in the US). Over 90% of the daily load of uric acid filtered by the kidneys is reabsorbed through renal transporters. These urate transporters include uric acid transporter 1 (URAT1), glucose transporter 9, and organic anion transporters 1, 3, and 4 (OAT1, OAT3, OAT4). They are the target of approved and in-the-pipeline uricosurics. Any drug that increases renal excretion of uric acid, independently of the mechanism through which it exerts its effect, may be considered a uricosuric drug. This review discusses drugs that increase renal excretion of uric acid, either approved or in development, as well as off-label drugs with uricosuric properties.

Frequently Encountered Artifacts in the Application of Dual-Energy Computed Tomography to Cardiovascular Imaging for Urate Crystals in Gout: A Matched-Control Study

OBJECTIVE

There is surging interest in using dual-energy computed tomography (DECT) to identify cardiovascular monosodium urate (MSU) deposits in patients with gout. We sought to examine the prevalence and characterization of cardiovascular DECT artifacts using non-electrocardiogram (EKG)-gated DECT pulmonary angiograms.

METHODS

We retrospectively reviewed non-EKG-gated DECT pulmonary angiograms performed on patients with and without gout at a single academic center. We noted the presence and locations of vascular green colorization using the default postprocessing two-material decomposition algorithm for MSU. The high- and low-energy grayscale images and advanced DECT measurements were used to determine whether they were true findings or artifacts. We classified artifacts into five categories: streak, contrast medium mixing, misregistration due to motion, foreign body, and noise.

RESULTS

Our study included CT scans from 48 patients with gout and 48 age- and sex-matched controls. The majority of patients were male with a mean age of 67 years. Two independent observers attributed all areas of vascular green colorization to artifacts. The most common types of artifacts were streak (56% vs 57% between patients and controls, respectively) and contrast medium mixing (51% vs 65%, respectively). Whereas some of the default DECT measurements of cardiovascular green colorization were consistent with values reported for subcutaneous tophi, advanced DECT measurements were not consistent with that of tophi.

CONCLUSION

Artifacts that could be misconstrued as cardiovascular MSU deposits were commonly identified in patients with and without gout on non-EKG-gated DECT pulmonary angiograms. These artifacts can inform future vascular DECT studies on patients with gout to minimize false-positive findings.

Lactococcus cremoris D2022 alleviates hyperuricemia and suppresses renal inflammation via potential gut-kidney axis

Hyperuricemia (HUA) is a widespread metabolic disorder. Probiotics have drawn increasing attention as an adjunctive treatment with fewer side effects. However, thus far the effective strains are limited and the mechanisms for their serum uric acid (SUA)-lowering effect are not well understood. Along this line, we conducted the current study using a hyperuricemia mouse model induced by potassium oxonate and adenine. A novel strain of Lactococcus cremoris named D2022 was identified to have significant SUA-lowering capability. Lactococcus cremoris D2022 significantly reduced SUA levels by inhibiting uric acid synthesis and regulating uric acid transportation. It was also found that Lactococcus cremoris D2022 alleviated HUA-induced renal inflammatory injury involving multiple signaling pathways. By focusing on the expression of NLRP3-related inflammatory genes, we found correlations between the expression levels of these genes and free fatty acid receptors (FFARs). In addition, oral administration of Lactococcus cremoris D2022 increased short-chain fatty acids (SCFAs) in cecal samples, which may be one of the mechanisms by which oral probiotics alleviate renal inflammation. Serum untargeted metabolomics showed changes in a variety of serum metabolites associated with purine metabolism and inflammation after oral administration of Lactococcus cremoris D2022, further confirming its systemic bioactivity. Finally, it was proved that Lactococcus cremoris D2022 improved intestinal barrier function. In conclusion, Lactococcus cremoris D2022 can alleviate HUA and HUA-induced nephropathy by increasing the production of SCFAs in the gut and systemic metabolism.

New Light on Plants and Their Chemical Compounds Used in Polish Folk Medicine to Treat Urinary Diseases

This review contains the results of Polish (Central Europe) ethnomedical studies that describe the treatment of urinary tract diseases with wild and cultivated plants. The study includes only the plants that are used to treat the urinary tract, excluding prostate diseases. A review of the literature was carried out to verify the pharmacological use of the plants mentioned in the interviews. Based on this, the study reviews the pharmacological activities of all the recorded species and indicates their most important chemical compounds. Fifty-three species (belonging to 30 families) were selected for the study. The Compositae (eight species), Rosaceae (six species), and Apiaceae (six species) are the most common families used in the treatment of urinary diseases in Polish folk medicine. Both in vitro and in vivo studies have confirmed that many of these plant species have beneficial properties, such as diuretic, antihyperuricemic, antimicrobial, and anti-inflammatory activity, or the prevention of urinary stone formation. These effects are exerted through different mechanisms, for example, through the activation of bradykinin B2 receptors, inhibition of xanthine oxidase, or inhibition of Na+-K+ pump. Many plants used in folk medicine are rich in phytochemicals with proven effectiveness against urinary tract diseases, such as rutin, arbutin, or triterpene saponins.

An exposome atlas of serum reveals the risk of chronic diseases in the Chinese population

Although adverse environmental exposures are considered a major cause of chronic diseases, current studies provide limited information on real-world chemical exposures and related risks. For this study, we collected serum samples from 5696 healthy people and patients, including those with 12 chronic diseases, in China and completed serum biomonitoring including 267 chemicals via gas and liquid chromatography-tandem mass spectrometry. Seventy-four highly frequently detected exposures were used for exposure characterization and risk analysis. The results show that region is the most critical factor influencing human exposure levels, followed by age. Organochlorine pesticides and perfluoroalkyl substances are associated with multiple chronic diseases, and some of them exceed safe ranges. Multi-exposure models reveal significant risk effects of exposure on hyperlipidemia, metabolic syndrome and hyperuricemia. Overall, this study provides a comprehensive human serum exposome atlas and disease risk information, which can guide subsequent in-depth cause-and-effect studies between environmental exposures and human health.

Associations of serum uric acid levels and anthropometric parameters with non-alcoholic fatty liver disease in healthy individuals: innovative insights from a cross-sectional study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD is a spectrum of liver disease with a rising prevalence, ranging from simple steatosis to steatohepatitis and cirrhosis, where a significant minority face potential complications. Determining the predictive markers plays a crucial role. This study examined the relationship between serum uric acid (SUA) levels and NAFLD in healthy individuals and identified potential other predictors.

MATERIAL AND METHODS

A cohort of 2162 healthy participants attending routine check-up visits between February 2021 and May 2023 were included. Participants underwent abdominal ultrasound, uric acid measurements, and anthropometric assessments by TANITA. NAFLD was graded using a "hepatic steatosis score." Statistical analysis included nonparametric tests, chi-squared tests, Fisher's exact test, ROC curve analysis, and logistic regression.

RESULTS

The median age was 45 years (range:18-65). 1017 were male, and 1145 were female. Among the participants, 53.9%, 26.3%, 17.9%, and 1.9% exhibited Grade 0, 1, 2, and 3 hepatic steatosis, respectively. ROC analysis showed 80.0% sensitivity and 78.8% specificity for detecting grade 2 or higher hepatic steatosis with a cutoff value of 5.21 mg/dl of SUA (AUC = 0.82, p < 0.001, 95%CI 0.79-0.84). There were significant associations between elevated uric acid levels and NAFLD. Participants with higher body fat percentages, BMI values, and waist-to-hip ratios also demonstrated an increased prevalence of steatosis. Gender significantly influenced liver steatosis, with males exhibiting higher grades compared to females. Logistic regression analysis highlighted positive associations between NAFLD and body fat percentage, waist-to-hip ratio, and uric acid levels. Each unit increase in uric acid levels corresponded to a 2.5-fold increase in the odds of NAFLD (p < 0.001, 95% CI = 2.20-2.84).

CONCLUSION

Our findings suggest a significant relationship between serum uric acid levels and NAFLD in healthy individuals. Elevated uric acid levels, in conjunction with other anthropometric parameters, may serve as potential predictive markers for NAFLD.

Probiotics, prebiotics, and postbiotics in health and disease

The gut microbiota and its homeostasis play a crucial role in human health. However, for some diseases related to the gut microbiota, current traditional medicines can only relieve symptoms, and it is difficult to solve the root causes or even cause side effects like disturbances in the gut microbiota. Increasing clinical studies and evidences have demonstrated that probiotics, prebiotics, and postbiotics can prevent and treat various diseases, but currently they can only be used as dietary supplements rather than medicines, which restricts the application of probiotics in the field of medicine. Here, this review analyzes the importance of gut microbiota in human health and the current problems of traditional medicines, and systematically summarizes the effectiveness and mechanisms of probiotics, prebiotics, and postbiotics in maintaining health and treating diseases based on animal models and clinical trials. And based on current research outcomes and development trends in this field, the challenges and prospects of their clinical application in maintaining health, alleviating and treating diseases are analyzed. It is hoped to promote the application of probiotics, prebiotics, and postbiotics in disease treatment and open up new frontiers in probiotic research.

Risk factors of nonalcoholic fatty liver disease in healthy women

We investigated the risk factors of nonalcoholic fatty liver disease (NAFLD) in healthy women. This is a cross-sectional study. Healthy women who underwent physical examination were enrolled. Their basic information and medical history [including age, height, weight, body mass index (BMI)], abdominal ultrasound results, and, serological indexes [including white blood cells, platelet count, fasting blood glucose, triglyceride (TG), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDLC), uric acid (UA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glutamyl transpeptidase] were collected. Univariate and multivariate regression analysis was carried out to screen the risk factors of NAFLD. ALT/AST ratio, and BMI were significantly independent risk factors for the occurrence and severity of NAFLD. In addition, TG/HDLC ratio, and UA level also had significant independent correlation with NAFLD. ALT/AST ratio, BMI, TG/HDLC ratio, and UA are independent risk factors for the occurrence and severity of NAFLD. It is suggested that obesity, hyperlipidemia, hyperuricemia and high transaminase value are closely related to NAFLD. People with such conditions should pay more attention to early screening of NAFLD to avoid disease aggravation and the occurrence and development of other complications. In clinical practice, ALT/AST, BMI, TG/HDLC, and UA level should be closely monitored, so as to facilitate the follow-up management of the disease.

The Associations Between Alanine Aminotransferase and Other Biochemical Parameters in Lean PCOS

To explore the associations of alanine aminotransferase in lean women of polycystic ovary syndrome (PCOS) with other biochemical parameters and the potential risk factors. This is a retrospective cohort study with lean PCOS (n = 91) and healthy controls (n = 45); we reviewed the electrical records and databases of the PCOS patients in our infertility clinic between January 2019 and September 2021; independent t-test, linear correlation analysis, and multiple linear regression were used to explore the associations. Higher levels of luteinizing hormone, total testosterone, thyroid stimulating hormone, platelet count, lymphocyte count, homocysteine, alanine aminotransferase (ALT), and uric acid were identified in lean PCOS patients, while follicle-stimulating hormone level was lower in in lean PCOS as expected (P < 0.05). Of note, the linear correlation showed that BMI, total testosterone, white blood cell count, lymphocyte count, aspartate aminotransferase, and uric acid were positively associated with alanine aminotransferase (r = 0.232, 0.318, 0.218, 0.388, 0.602, 0.353 respectively, P < 0.05). After multiple linear regression was performed, total testosterone and aspartate aminotransferase were independently and positively correlated with alanine aminotransferase in lean PCOS (B = 0.251, 0.605 respectively, P < 0.05). Higher level of ALT was identified in the lean PCOS. BMI, white blood cell count, lymphocyte count, aspartate aminotransferase, uric acid, and total testosterone were positively correlated with ALT in lean PCOS. Total testosterone and aspartate aminotransferase were independently and positively associated with ALT in lean PCOS after multiple linear regression. There might exist a potential risk of afflicting liver impairment for the lean PCOS women in the earlier period. Early examination and intervention might be necessary to prevent or delay the progression of the liver disease as soon as the diagnosis of PCOS.

The role of lipid profile in the relationship between particulate matters and hyperuricemia: A prospective population study

CONTEXT

Recent studies in specific population subgroups (e.g., pregnant women) have suggested PM exposure increases the risk of hyperuricemia. However, no studies have examined this in the general population. Furthermore, the underlying mechanism through which PM impacts hyperuricemia risk is poorly understood.

OBJECTIVE

To assess the association between long-term exposure to PM and risk of hyperuricemia and whether this association is mediated by lipid profile.

METHODS

We included 5939 participants in Southwest China from the China Multi-Ethnic Cohort (baseline 2018-2019, follow-up 2020-2021). Long-term PM pollutants (PM₁, PM_2.5, PM₁₀) exposure for each individual was represented by the three-year average PM levels before the baseline survey. Hyperuricemia at follow-up was defined as the serum uric acid above 7.0 mg/dL in men and 6.0 mg/dL in women. Serum lipids were measured at baseline including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). The association of PM with hyperuricemia was accessed through logistic regression. The potential mediation effects of serum lipids were evaluated through causal mediation analyses.

RESULTS

A total of 837 participants were newly diagnosed with hyperuricemia. The odds ratios of hyperuricemia associated with an interquartile range (IQR) increase in PM₁, PM_2.5, and PM₁₀ (IQR: 21.10, 25.78, 30.43 μg m^-3) were 1.72 (95% CI: 1.23, 2.39), 2.68 (95% CI: 1.59, 4.49), and 1.81 (95% CI: 1.20, 2.72), respectively. The association between PM_2.5, PM₁, and PM₁₀ on hyperuricemia was mediated by HDL-C (10%) and LDL-C (3%).

CONCLUSION

Higher particulate matter exposure was associated with higher hyperuricemia incidence. The decline in HDL-C and rise in LDL-C partially mediated this association. These findings were conducive to scientific research about the underlying mechanism of PM on hyperuricemia.

Association of Serum Uric Acid With Retinal Capillary Plexus

BACKGROUND

To determine the association between serum uric acid (SUA) and the retinal capillary plexus (RCP) using optical coherence tomography angiography (OCTA).

METHODS

This cross-sectional study evaluated data from August 2019 to January 2020 from participants recruited from the Jidong community (Tangshan, Hebei, China). All participants completed detailed anthropometrical measurements, laboratory tests and comprehensive ophthalmic examinations. We assessed the vessel density in RCP using OCTA. We used multivariable analysis to evaluate the sex-specific association between SUA and RCP after adjusting for confounders.

RESULTS

A total of 2730 participants were included in this study. The mean age of the participants was 44.0 ± 11.6 years, and 1463 (53.6%) were women. The multivariable βs and 95% confidence intervals (CIs) of superficial RCP vessel density in the second through fourth SUA quartiles compared with the lowest SUA quartiles were -0.27 (-0.56 - 0.03), -0.30 (-0.60 - 0.01), and -0.46 (-0.78 - -0.14) (P for trend = 0.007) in men.

CONCLUSIONS

Higher SUA levels were significantly associated with lower RCP vessel density in men. Our findings provide evidence for the detrimental effect of high SUA levels on the retinal microvasculature and imply the importance of modulating SUA to prevent the microvascular alternation especially for men.

Dose-Response Relationship Between BMI and Hyperuricemia

OBJECTIVE

The purpose of the current study is to explore the demographic characteristics of hyperuricemia in China.

STUDY DESIGN

The cross-sectional study was conducted, and the CHARLS dataset in 2011 was used.

METHODS

Logistic regression model was used to assess the association between BMI and hyperuricemia. We also used restricted cubic spline with three knots to assess the dose-response relationship. To investigate the differences in dose-response relationships in various groups, stratification analysis was conducted.

RESULTS

Of the 9408 middle and older participants, those who were overweight or obese had higher risk for hyperuricemia (OR=1.26, 95% CI=1.01-1.57; OR=1.90, 95% CI=1.46-2.47). In the subgroup, the effect of obesity on hyperuricemia was robust in varying gender and age. However, among overweight group, those with being male and aged over 60 years had higher risk for hyperuricemia (male: OR=1.42, 95% CI=1.07-1.90; over 60 years: OR=1.28, 95% CI=1.03-1.60). A dose-response relationship was examined between BMI and the risk of hyperuricemia. The result showed that the odds ratio of hyperuricemia and BMI displayed U-shaped nonlinear relationship (P trend<0.001, non-linear P<0.001).

CONCLUSION

The association between BMI and hyperuricemia showed positive relationship. Specifically, the group with male and age over 60 years had higher risk of hyperuricemia along with increased weight.

Assessment of the relationship between serum uric acid levels and liver enzymes activity in Bangladeshi adults

Serum uric acid (SUA) level has been suggested to be associated with cardiovascular disease, diabetes and metabolic syndrome. However, little is known about the relationship between SUA and liver enzymes activity in the general population. The present study aimed to assess the relationship between SUA and serum liver enzymes in an adult population in Bangladesh. In this cross-sectional study, a total of 410 blood samples were collected from apparently healthy adults aged > 18 years. SUA, liver enzymes, lipid profile and other biochemical markers were measured in the collected samples by using standard methods. Multinomial logistic regression model was used to assess the relationship between SUA and elevated levels of liver enzymes among the participants. Overall, the prevalence of hyperuricemia was 30.1% with 32.2% in male and 18.6% in female participants. About 33% of the participants had at least one or more elevated levels of liver enzymes. The mean level of SUA was significantly higher in males (389.3 ± 96.9 µmol/L) than in the female (290.4 ± 89.8 µmol/L) subjects (p < 0.001). There was a significant difference in the mean levels of serum ALT and GGT between the male (34.5 ± 16.0 U/L and 26.7 ± 19.5 U/L, respectively) and female (25.0 ± 13.0 U/L and 19.5 ± 13.2 U/L, respectively) participants (p < 0.001 and p < 0.01, respectively). An increasing trend was observed in the mean levels of serum ALT and GGT across the SUA quartile groups (p < 0.001 and p < 0.01, respectively). SUA showed a positive and significant correlation with serum ALT (p < 0.001) and GGT (p < 0.01). In further statistical analysis after adjustment for potential confounders, SUA showed an independent and significant association with serum ALT and GGT in all regression models. In conclusion, SUA was strongly associated with serum levels of ALT and GGT after adjustment for potential confounders. More prospective studies are needed to clarify the complex relationship between SUA and liver enzymes in the general population.

Hyperuricemia Among Egyptian Rheumatoid Arthritis Patients. Is It an Association or an Inflammatory Marker? A Cross-Sectional Observational Study

OBJECTIVE

To detect the prevalence of hyperuricemia in Egyptian rheumatoid arthritis (RA) patients as well as to assess its association with the severity of joint inflammation and disease-modifying antirheumatic drugs (DMARDs) in those patients.

METHODS

A total of 150 RA patients were recruited; all patients were subjected to (1) clinical and functional assessment by disease activity score in 28 joints (DAS28) and modified health assessment questionnaire (MHAQ). (2) Laboratory investigations: serum uric acid (SUA) level, complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), tumor necrosis factor α (TNF-α), interleukin 1 (IL1), and interleukin 6 (IL6) levels. (3) Radiological evaluation: (A) plain X-ray of both hands and feet; (B) musculoskeletal ultrasound (MSUS) of both wrists, hands, shoulder, ankle, and knee joints.

RESULTS

SUA was significantly correlated with disease activity by DAS28. Acute-phase reactants and inflammatory markers (IL1β, IL6, and TNF-α) were also significantly elevated in RA patients with low and high hyperuricemia compared to those with normal SUA. A total of 90% of RA patients with low hyperuricemia had synovial proliferation with power Doppler (1+ and 2+), and 30 patients had mild effusion (1+), while nearly all patients with high hyperuricemia had hypoechoic synovial proliferation (2+ and 3+), and 20 patients had moderate effusion. However, 70% RA patients with normal serum uric acid showed mild synovitis and effusion (1+). No significant association was found between the administered DMARDs and levels of SUA as well as inflammatory markers; however, high-dose steroid treatment was associated with high SUA level.

CONCLUSION

Elevation of serum uric acid levels in Egyptian RA patients was prevalent and might be an inflammatory marker for severity of joint inflammation. Moreover, higher doses of steroids could be considered a cause of hyperuricemia.

Function of Uric Acid Transporters and Their Inhibitors in Hyperuricaemia

Disorders of uric acid metabolism may be associated with pathological processes in many diseases, including diabetes mellitus, cardiovascular disease, and kidney disease. These diseases can further promote uric acid accumulation in the body, leading to a vicious cycle. Preliminary studies have proven many mechanisms such as oxidative stress, lipid metabolism disorders, and rennin angiotensin axis involving in the progression of hyperuricaemia-related diseases. However, there is still lack of effective clinical treatment for hyperuricaemia. According to previous research results, NPT1, NPT4, OAT1, OAT2, OAT3, OAT4, URAT1, GLUT9, ABCG2, PDZK1, these urate transports are closely related to serum uric acid level. Targeting at urate transporters and urate-lowering drugs can enhance our understanding of hyperuricaemia and hyperuricaemia-related diseases. This review may put forward essential references or cross references to be contributed to further elucidate traditional and novel urate-lowering drugs benefits as well as provides theoretical support for the scientific research on hyperuricemia and related diseases.

Higher Serum Uric Acid Levels Are Associated With an Increased Risk of Vision-Threatening Diabetic Retinopathy in Type 2 Diabetes Patients

Purpose

To investigate the association between serum uric acid (SUA) levels and vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes.

Methods

This cross-sectional study evaluated 3481 patients with type 2 diabetes from four communities in China between 2016 and 2019. VTDR was defined as severe nonproliferative, proliferative diabetic retinopathy, or clinically significant macular edema evaluated by fundus photography and optical coherence tomography. Potential association between SUA and VTDR was examined using multivariable logistic regression. Sub-group analyses based on sex were constructed.

Results

A total of 305 participants had VTDR. Both higher SUA (odds ratio [OR], 1.22 per 100 µmol/L; 95% confidence interval [CI], 1.04–1.44; P = 0.013) and hyperuricemia (OR, 1.47; 95% CI, 1.07–2.04; P = 0.019) were positively associated with VTDR after adjustment for relevant covariates. Compared with those in the lowest SUA quartile, participants in the third (OR, 1.60; 95% CI, 1.07–2.39; P = 0.022) and fourth (OR, 2.05; 95% CI, 1.37–3.08; P = 0.001) sex-specific SUA quartiles showed a significantly increased risk of VTDR after adjustment. No sex-related difference was observed.

Conclusions

Higher SUA levels were associated with an increased risk of VTDR in patients with type 2 diabetes in both sexes, although females seemed to be more sensitive to high SUA than males. Prospective cohort studies are needed to verify SUA as a biomarker for predicting the risk of VTDR. Whether decreased SUA levels could decrease the risk of VTDR also requires further investigation.

Febuxostat mitigates concanavalin A-induced acute liver injury via modulation of MCP-1, IL-1β, TNF-α, neutrophil infiltration, and apoptosis in mice

AIM

Liver plays a crucial role in innate immunity reactions. This role predisposes the liver to innate-mediated liver injury when uncontrolled inflammation occurs. In this study, the effect of febuxostat administration on acute liver injury induced by concanavalin A (Con A) injection into mouse eye orbital sinus was studied.

MATERIALS AND METHODS

Two doses of febuxostat (10 and 20 mg/kg, orally) were administered either 1 h before or 30 min after the administration of Con A. Febuxostat at a low dose (10 mg/kg) before and after Con A modulated the elevation of serum ALT, liver uric acid, liver myeloperoxidase (MPO), and interleukin-1β (IL-1β) induced by Con A. The same dose of febuxostat before Con A also decreased serum total bilirubin and neutrophil infiltration, as evidenced by flow cytometry and histopathological analysis.

KEY FINDINGS

Febuxostat at a high dose (20 mg/kg) significantly improved serum ALT, AST, albumin, total bilirubin, liver uric acid, MPO, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), IL-1β, and neutrophil infiltration induced by Con A administration. The results of histopathological examination of liver cells paralleled the observed biochemical improvements. Hepatocyte apoptosis as evidenced by immunohistochemical examination of cleaved caspase-3 was markedly decreased in the febuxostat protection and treatment groups, in a dose-dependent manner SIGNIFICANCE: These results indicate that febuxostat, especially at the higher dose, may be an effective inhibitor of immune reactions evoked by Con A administration.

Uric acid and its correlation with hypertension in postmenopausal women: A multi-ethnic study (Observational study)

We investigate the association of uric acid with hypertension among Han, Uygur, and Kazakh populations in the Xinjiang Province of Western China. Our study aims to evaluate the relationships of serum uric acid (SUA) with hypertension in the Chinese population according to the menopausal status. Medical data of 1684 Han, 1895 Uygur, and 294 Kazakh people was examined. The prevalence of hypertension was calculated by the quartiles of SUA. Correlation between hypertension-related risk factors calculated and compared between men and women. SUA was higher in men than in women. The level was significantly higher in postmenopausal than premenopausal women (4.40 ± 1.75 v.s 4.06 ± 1.63 mg/dl, P < .01). Logistic regression analysis showed Body mass index (BMI) [OR = 1.08, P < .01]; and eGFR<60 vs.≥60 [OR = 1.22, P = .04] were independent risk factors for hypertension in women. Age and diabetes were independent risk factors for the participants with hypertension [OR = 1.04, P < .01] and [OR = 2.24, P < .01]. High quartile SUA group has increased the risk for hypertension in postmenopausal women [OR = 1.34, P = .048]. We found that postmenopausal women have high SUA compared to premenopausal women. The high SUA quartiles uric acid may be an independent risk for hypertension in postmenopausal women.

Prevention of Hyperuricemia by Clerodendrum trichotomum Leaf Extract in Potassium Oxonate-Induced Mice

Clerodendrum trichotomum is a folk medicine exhibiting anti-hypertension, anti-arthritis, and anti-rheumatism properties. However, little is known about whether the material might prevent hyperuricemia and associated inflammation. In this study, we explored whether C. trichotomum leaf extract (CTE) prevented hyperuricemia induced by potassium oxonate (PO) in mice. CTE (400 mg/kg body weight) significantly reduced the serum uric acid (UA), blood urea nitrogen (BUN), and serum creatinine levels and increased urine UA and creatinine levels. CTE ameliorated PO-induced inflammation and apoptosis by reducing the levels of relevant proteins in kidney tissues. Also, CTE ameliorated both UA-induced inflammatory response in RAW 263.7 cells and UA-induced cytotoxicity in HK-2 cells. In addition, liver transcriptome analysis showed that CTE enriched mainly the genes for mediating positive regulation of MAPK cascade and apoptotic signaling pathways. Together, the results show that CTE effectively prevents hyperuricemia and associated inflammation in PO-induced mice.

Association of gout with CAD and effect of antigout therapy on CVD risk among gout patients

Hyperuricemia has been identified as an independent risk factor for coronary artery disease (CAD), with a dose-response association. In this study, we explored the causal association between gout and antigout medication and the risk of incidental CAD. We sampled data from the National Health Insurance Research Database and recruited 37,091 patients as the gout cohort, and 37,091 controls. Our primary endpoint was the diagnosis of CAD during follow-up. The overall study population was followed up until CAD diagnosis, withdrawal from the National Health Insurance program, or the end of the study. Cox proportional hazards regression models were used to examine the effect of gout on the risk of CAD, represented by the HR with the 95% CI. Patients with gout were at greater risk of CAD, compared with those without gout: HR=1.49 after adjusting for potential confounders. Non-steroidal anti-inflammatory drugs and prednisolone use was associated with a reduced risk of CAD: HR=0.63 and 0.50, respectively. Patients with gout, treated with antigout medication, exhibited a reduced risk of CAD compared with non-gout patients. Among patients with gout, those on antigout therapy had 32% lower risk compared with those not on antigout therapy: adjusted HR=0.68, 95% CI 0.63 to 0.73. Gout increases the risk of CAD, and the use of antigout medication reduces CAD risk. These results indicate that gout or hyperuricemia is a modifiable risk factor for CAD.

Genome-wide meta-analysis identifies multiple novel loci associated with serum uric acid levels in Japanese individuals

Gout is a common arthritis caused by elevated serum uric acid (SUA) levels. Here we investigated loci influencing SUA in a genome-wide meta-analysis with 121,745 Japanese subjects. We identified 8948 variants at 36 genomic loci (P<5 × 10-8) including eight novel loci. Of these, missense variants of SESN2 and PNPLA3 were predicted to be damaging to the function of these proteins; another five loci-TMEM18, TM4SF4, MXD3-LMAN2, PSORS1C1-PSORS1C2, and HNF4A-are related to cell metabolism, proliferation, or oxidative stress; and the remaining locus, LINC01578, is unknown. We also identified 132 correlated genes whose expression levels are associated with SUA-increasing alleles. These genes are enriched for the UniProt transport term, suggesting the importance of transport-related genes in SUA regulation. Furthermore, trans-ethnic meta-analysis across our own meta-analysis and the Global Urate Genetics Consortium has revealed 15 more novel loci associated with SUA. Our findings provide insight into the pathogenesis, treatment, and prevention of hyperuricemia/gout.

The Liver in Children With Metabolic Syndrome

Non-alcoholic fatty liver disease (NAFLD) is recognized as an emerging health risk in obese children and adolescents. NAFLD represents a wide spectrum of liver conditions, ranging from asymptomatic steatosis to steatohepatitis. The growing prevalence of fatty liver disease in children is associated with an increased risk of metabolic and cardiovascular complications. NAFLD is considered the hepatic manifestation of Metabolic Syndrome (MetS) and several lines of evidence have reported that children with NAFLD present one or more features of MetS. The pathogenetic mechanisms explaining the interrelationships between fatty liver disease and MetS are not clearly understood. Altough central obesity and insulin resistance seem to represent the core of the pathophysiology in both diseases, genetic susceptibility and enviromental triggers are emerging as crucial components promoting the development of NAFLD and MetS in children. In the present review we have identified and summarizied studies discussing current pathogenetic data of the association between NAFLD and MetS in children.

White blood cell count: an independent predictor of coronary heart disease risk in middle-aged and elderly population with hyperuricemia

Previous studies have shown that hyperuricemia is an independent risk factor for cardiovascular disease. The aim of the study was to examine the association between white blood cell (WBC) count and coronary heart disease (CHD) risk in middle-aged and elderly population with hyperuricemia.Data included in this analysis were from a population-based cross-sectional study, that is, the Xiangya Hospital Health Management Center Study. Hyperuricemia was defined as uric acid ≥416 μmol/L in male population and ≥360 μmol/L in female population. The WBC count was classified into 3 categories based on the tertile distribution of the study population. Framingham risk scores calculated by the Adult Treatment Panel III charts were used to estimate 10-year CHD risk for each participant. The relationship between WBC count and CHD risk in patients with hyperuricemia was examined using the multivariable logistic analysis.A total of 1148 hyperuricemia patients (855 males and 293 females) aged from 40 to 85 years were included and 418 (36.4%) of them were defined with relatively high 10-year CHD risk. Compared with the lowest tertile, the crude odds ratios (ORs) of high 10-year CHD risk were 1.43 (95% confidence interval [CI] 1.06-1.92) and 1.56 (95% CI 1.16-2.11) in the 2nd and 3rd tertiles of WBC count (P for trend = .004), and the multivariable adjusted ORs of high 10-year CHD risk were 1.39 (95% CI 1.03-1.89) and 1.47 (95% CI 1.08-2.00) in the 2nd and 3rd tertiles of WBC count (P for trend = .015).This study indicated that WBC count was associated with CHD risk in patients with hyperuricemia, suggesting that WBC count, an easily accessible biomarker, could probably predict CHD risk in middle-aged and elderly population with hyperuricemia.

Increased risk of adhesive capsulitis among patients with gout: A nationwide population-based matched-cohort study

AIM

The pathophysiology of adhesive capsulitis (AC) is uncertain. We noted patients with gout seemed to have higher incidence rates of AC than other people in our clinic. We did not know the true relationship between gout and AC because there are no published reports so far. The aim of this study is to verify the risk of developing AC following gout exposure.

METHOD

The authors used the National Health Insurance Research Database of Taiwan to select 39 094 subjects with newly diagnosed gout and randomly extracted 78 188 matched control subjects. All of the subjects in study and control groups were followed until the event of AC. Cox proportional hazard regression analyses were performed to evaluate the subsequent risk of AC.

RESULTS

There was significance since the 8th year of tracking that patients with gout had a higher risk for AC (log-rank test P < .001). Cox regression showed the adjusted hazard ratio of developing AC for patients with gout was 1.71 (95% CI = 1.451-2.565, P < .001) than the control group. Stratified analysis showed that gout patients have a higher risk for AC regardless of diabetes mellitus, stroke or carotid artery disease (P < .05).

CONCLUSIONS

This study showed that gout is an independent risk factor for developing AC.

Mediterranean diet adherence and synergy with acute myocardial infarction and its determinants: A multicenter case-control study in Italy

Background

Cardiovascular diseases are the leading causes of mortality and morbidity in Western countries. The possible synergistic effect of poor adherence to a Mediterranean diet (MD) and other risk factors for acute myocardial infarction (AMI) such as hypertension, cholesterol, ever smoker, BMI> 25, diabetes, has not been deeply studied.

Design

Case-control study.

Methods

Patients with first AMI and controls from four tertiary referral Italian centers were screened for enrolment. Dietary information was collected through a questionnaire and a MD adherence score was calculated. Physical activity and smoking habits were also registered. The Synergy Index was calculated according to Rothman.

Results

127 cases and 173 controls were enrolled. The analysis was conducted using a dichotomous variable for the MD score with values ≥7 representing good adherence. Multivariate analysis showed the following variables associated to AMI: ever smoker (OR = 2.08), diabetes (OR = 1.42), hypertension (OR = 2.08), hypercholesterolemia (OR = 2.47), BMI> 25 (OR = 1.99), while a protective effect emerged both in subjects scoring > 7 on the MD score (OR = 0.55) and in subjects resident of Southern Italy (OR = 0.38). A synergistic effect does exist between poor adherence to the MD and the following risk factors: hypertension, hypercholesterolemia, BMI >25, diabetes and being a resident in central and northern Italy.

Conclusion

Synergy between heart disease risk factors and MD underlines the need to enlarge the list of known modifiable cardiovascular risk factors to include and promote adherence to Mediterranean dietary habits.

Vascular endothelium dysfunction: a conservative target in metabolic disorders

AIM

Vascular endothelium plays a role in capillary transport of nutrients and drugs and regulates angiogenesis, homeostasis, as well as vascular tone and permeability as a major regulator of local vascular homeostasis. The present study has been designed to investigate the role of endothelium in metabolic disorders.

METHODS

The endothelium maintains the balance between vasodilatation and vasoconstriction, procoagulant and anticoagulant, prothrombotic and antithrombotic mechanisms.

RESULTS

Diabetes mellitus causes the activation of aldose reductase, polyol pathway and advanced glycation-end-product formation that collectively affect the phosphorylation status and expression of endothelial nitric oxide synthatase (eNOS) and causes vascular endothelium dysfunction. Elevated homocysteine levels have been associated with increase in LDL oxidation, generation of hydrogen peroxides, superoxide anions that increased oxidative degradation of nitric oxide. Hyperhomocysteinemia has been reported to increase the endogenous competitive inhibitors of eNOS viz L-N-monomethyl arginine (L-NMMA) and asymmetric dimethyl arginine (ADMA) that may contribute to vascular endothelial dysfunction. Hypercholesterolemia stimulates oxidation of LDL cholesterol, release of endothelins, and generation of ROS. The increased cholesterol and triglyceride level and decreased protective HDL level, decreases the activity and expression of eNOS and disrupts the integrity of vascular endothelium, due to oxidative stress. Hypertension also stimulates release of endothelins, vasoconstrictor prostanoids, angiotensin II, inflammatory cytokines, xanthine oxidase and, thereby, reduces bioavailability of nitric oxide.

CONCLUSION

Thus, the cellular and molecular mechanisms underlying diabetes mellitus, hyperhomocysteinemia, hypercholesterolemia hypertension and hyperuricemia leads to an imbalance of phosphorylation and dephosphorylation status of lipid and protein kinase that cause modulation of vascular endothelial L-arginine/nitric oxide synthetase (eNOS), to produce vascular endothelium dysfunction.

Urate-Lowering Therapy Ameliorates Kidney Function in Type 2 Diabetes Patients With Hyperuricemia

Background

Hyperuricemia often causes kidney dysfunction which increases serum urate, forming a vicious cycle in the kidney. In this study, urate-lowering therapy was demonstrated in type 2 diabetic patients with hyperuricemia to evaluate the effect on diabetic nephropathy.

Methods

Type 2 diabetic patients with hyperuricemia (n = 34) were treated by urate-lowering drugs. Serum urate levels, estimated glomerular filtration rate (eGFR), blood pressure, HbA1c, and urinary albumin-to-creatinine ratio (UACR) were measured for 52 weeks. The parameters at the endpoint when serum urate decreased to below 6.0 mg/dL and at 52 weeks were compared to the initial levels at week 0.

Results

Serum urate level decreased to the endpoint in all patients and was maintained at under 6.0 mg/dL throughout the observation period. eGFR significantly increased at the endpoint and also at 52 weeks. Overall UACR did not change after 52 weeks; however, the treatment decreased UACR significantly in patients with no microalbuminuria. There was a negative relationship between the change of serum urate levels and the change of eGFR, and a negative relationship between the baseline UACR and the change of UACR when patients with macroalbuminuria were excluded. There were no changes in HbA1c levels and blood pressure before and after the treatment.

Conclusions

There were significant improvements in kidney function by lowering serum urate levels to under 6.0 mg/dL and the effect was maintained for at least 52 weeks. This treatment may be one strategy to slow the progression of nephropathy in type 2 diabetic patients with hyperuricemia.

Hyperuricemia is associated with nonalcoholic fatty liver disease activity score in patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Hyperuricemia is a significant risk factor for nonalcoholic fatty liver disease (NAFLD). It may also have an impact on the histologic severity of NAFLD. However, data on this association are limited. We conducted this meta-analysis to investigate the relationship of serum uric acid with liver histologic severity as determined by NAFLD activity score (NAS) in patients with NAFLD.

PATIENTS AND METHODS

MEDLINE and EMBASE databases were searched through August 2016 for studies that investigated the association between hyperuricemia and NAS among patients with biopsy-proven NAFLD. Pooled odds ratio and 95% confidence interval were calculated using a random-effects model (generic inverse variance method). The between-study heterogeneity of effect size was quantified using the Q statistic and I.

RESULTS

Five observational studies with 777 NAFLD patients were identified. Patients with NAFLD who had hyperuricemia had a high NAS (defined as score of ≥5) significantly more often than did those without hyperuricemia with a pooled odds ratio of 2.17 (95% confidence interval: 1.51-3.12). The statistical heterogeneity was low, with I of 16% (Pheterogeneity=0.31).

CONCLUSION

In patients with NAFLD, hyperuricemia is associated with a higher degree of histological liver damage. Further studies are required to establish the role of uric acid-lowering therapy among these patients.

Hyperuricemia and clustering of cardiovascular risk factors in the Chinese adult population

Hyperuricemia is common in China and the relevance of hyperuricemia and cardiovascular disease (CVD) risk has been highlighted, but to date there has been rarely nation-wide study in China. Here, we aim to estimate the current prevalence of hyperuricemia and evaluate the associations between hyperuricemia and cardiovascular risk factors (CRFs) clustering in a large sample of China adults including a plurality of ethnic minorities. Generally, a nationally representative sample of 22983 adults aged ≥18 years was recruited from 2007 to 2011. Questionnaire data and information on anthropometric characteristics, and laboratory measurements were collected. We define hyperuricemia as SUA ≥416 mmol/L for men and SUA ≥357 mmol/L for women. We found that the prevalence of hyperuricemia was 13.0% (18.5% in men and 8.0% in women). To our estimation, hyperuricemic subjects had higher prevalence rates of CRFs clustering than non-hyperuricemic subjects. Furthermore, there was a dose-response association between the number of CVD risk factors clustering and hyperuricemia. Our study revealed a high prevalence of hyperuricemia and CVD risk factors clustering among Chinese adults, and hyperuricemia was significantly associated with coexistence of more CVD risk factors. Therefore, guidance and effective lifestyle intervention are required to prevent hyperuricemia and CVD risk factors in China.

Serum uric acid concentration is associated with hypertensive retinopathy in hypertensive chinese adults

BACKGROUND

This cross sectional investigation included 12,966 subjects with hypertension, a cohort of the China Stroke Primary Prevention Trial (CSPPT), a randomized, multicenter clinical trial. This study aimed to explore the correlation between serum uric acid (SUA) concentration and hypertensive retinopathy in hypertensive adults.

METHODS

Diagnosis of hypertensive retinopathy was determined by non-mydriatic fundus photography and classified with Keith-Wagener-Barker (KWB) system. The correlation of SUA levels with hypertensive retinopathy prevalence and severity was assessed by statistical analysis.

RESULTS

9848 (75.95%) subjects were diagnosed with hypertensive retinopathy with the following retinopathy grade distribution: grade 1: 58.80%, grade 2: 14.81%, and grade 3-4: 2.34%. SUA levels were significantly associated with hypertensive retinopathy prevalence. Patients with hypertensive retinopathy had higher SUA levels than those without hypertensive retinopathy. Patients in the highest uric acid quartile had an odds ratio for hypertensive retinopathy of 1.21 compared to patients in the lowest uric acid quartile (OR = 1.21, 95% CI: 1.05-1.40, P = 0.008). When compared to the non-hyperuricemia group, those in the hyperuricemia group had an odds ratio for hypertensive retinopathy of 1.18(OR = 1.18, 95% CI: 1.05-1.33, P = 0.004). Every 1 mg/dl increase in uric acid concentration was significantly associated with a 6% higher odds of hypertensive retinopathy (OR = 1.06, 95% CI: 1.02-1.10, P = 0.002).

CONCLUSIONS

The prevalence of hypertensive retinopathy was high (75.95%) among hypertensives in our patients cohort. In addition, SUA concentration was significantly associated with hypertensive retinopathy.

Hyperuricemia is not associated with severity of liver fibrosis in patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Uric acid is a natural antioxidant. Previous studies have suggested a protective role of hyperuricemia against liver fibrosis among patients with nonalcoholic fatty liver disease (NAFLD). However, the results were conflicting.

METHODS

MEDLINE and EMBASE databases were searched through August 2016 for studies that investigated the association between hyperuricemia and fibrosis stage among patients with biopsy-proven NAFLD. Pooled odds ratio and 95% confidence interval were calculated using a random-effects model, generic inverse variance method of DerSimonian and Laird. The between-study heterogeneity of effect size was quantified using the Q statistic and I.

RESULTS

A total of five observational studies with 749 NAFLD patients were identified. Patients with NAFLD who had hyperuricemia were not significantly more likely or less likely to have advanced liver fibrosis (defined as fibrosis stage of ≥3) compared with patients with NAFLD who had normal serum uric with the pooled odds ratio of 0.72 (95% confidence interval: 0.34-1.53). The statistical heterogeneity was low with an I of 22% (Pheterogeneity=0.27).

CONCLUSION

Significant protective role of hyperuricemia against the development of advanced liver fibrosis in patients with NAFLD was not observed in this meta-analysis.

Rosehip inhibits xanthine oxidase activity and reduces serum urate levels in a mouse model of hyperuricemia

Rosehip, the fruit of Rosa canina L., has traditionally been used to treat urate metabolism disorders; however, its effects on such disorders have not been characterized in detail. Therefore, the present study investigated the effects of hot water, ethanol and ethyl acetate extracts of rosehip on xanthine oxidase (XO) activity in vitro. In addition, the serum urate lowering effects of the rosehip hot water extract in a mouse model of hyperuricemia (male ddY mice, which were intraperitoneally injected with potassium oxonate) were investigated. Furthermore, the influence of rosehip hot water extract on CYP3A4 activity, which is the most important drug-metabolizing enzyme from a herb-drug interaction perspective, was investigated. Rosehip extracts of hot water, ethanol and ethyl acetate inhibited XO activity [half maximal inhibitory concentration (IC50) values: 259.6±50.6, 242.5±46.2 and 1,462.8±544.2 µg/ml, respectively]. Furthermore, the administration of 1X rosehip hot water extract significantly reduced the levels of serum urate at 8 h, which was similar when compared with the administration of 1 mg/kg allopurinol. Rosehip hot water extract only marginally affected CYP3A4 activity (IC50 value, >1 mg/ml). These findings indicate that rosehip hot water extract may present as a functional food for individuals with a high urate level, and as a therapeutic reagent for hyperuricemic patients.

Relationship of serum uric acid level with non-alcoholic fatty liver disease and its inflammation progression in non-obese adults

AIM

This study aimed to evaluate the relationship between serum uric acid (SUA) level and non-alcoholic fatty liver disease (NAFLD) in non-obese adults.

METHODS

A cross-sectional study was carried out among 4098 adults, including 1936 non-obese and 2162 obese individuals. An additional 93 non-obese adults with biopsy-proven NAFLD were also included.

RESULTS

The overall prevalence of NAFLD was 39.51% in the study group, and 14.88% in non-obese adults. The NAFLD patients had significantly higher SUA levels than controls in both men and women. The non-obese group had a higher NAFLD risk with increased SUA levels than the obese group, with odd ratios (95% confidence interval) of 2.559 (1.870-3.503) and 1.692 (1.371-2.087), respectively. In 93 non-obese adults with biopsy-proven NAFLD, SUA levels were significantly higher in those with non-alcoholic steatohepatitis. The prevalence of non-alcoholic steatohepatitis and lobule inflammation tended to increase to 57.58% and 66.67% as the SUA level increased to the fourth quartile. Subjects with hyperuricemia had significantly higher NAFLD activity scores and more serious lobule inflammation than the normal group.

CONCLUSION

Non-obese adults have higher NAFLD risk with increased SUA levels than obese individuals, and the inflammation progression of NAFLD is associated with increased SUA level in non-obese subjects.

Association between Gout and Erectile Dysfunction: A Systematic Review and Meta-Analysis

Background

The aim of this systematic review and meta-analysis was to assess the possible association between gout and erectile dysfunction (ED).

Methods

Studies were identified by extensively searching EMBASE, Pubmed, CENTRAL and ISI Web of Science. Four electronic databases were searched from their inception date to the latest issue (March 2016), without language restriction. Each reviewer screened articles independently and was blinded to the findings of the other reviewer. Data was extracted in adherence to the predetermined data collection form and meta-analysis was conducted via RevMan 5.3.

Results

Five studies involving 56465 patients (mean age: 49.11 years) with gout and 155636 non-gout subjects (mean age: 48.76 years) were selected. The combination of unadjusted odds ratio (OR) showed that patients with gout were 1.44 times more likely to be diagnosed with ED when compared with control (95% confidence interval (95%CI) 1.20, 1.72). After adjustment for age and comorbidities, the heightened risk to develop ED was still present (1.18, 95%CI 1.02, 1.38). Subgroup-analysis by age showed statistically significant association of gout and ED in all age groups. However, evidence supporting a causal effect of gout on ED was insufficient.

Conclusion

The findings of this review indicated a positive association of gout and ED, but this work is hampered by the heterogeneity among included studies, to some extent. Future studies with larger community-based homogeneous population and randomized controlled trials aimed to evaluate the effect of gout treatment on ED associated outcomes are needed at this point.

Hyperuricemia protects against low bone mineral density, osteoporosis and fractures: a systematic review and meta-analysis

BACKGROUND

Serum uric acid (SUA) accounts for about 50% of extracellular antioxidant activity, suggesting that hyperuricemia may have a protective role in diseases characterized by high levels of oxidative stress, such as osteoporosis. We aimed to meta-analyse data regarding bone mineral density (BMD), osteoporosis and fractures in people with higher SUA vs. lower SUA concentrations.

MATERIALS AND METHODS

Two investigators conducted a literature search using PubMed and Scopus, without language restrictions. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were used for BMD; risk ratios (RRs) and adjusted odds ratios (ORs) for cross-sectional data. Most possible adjusted hazard ratios (HRs) were used to assess the association between baseline SUA and incident fractures.

RESULTS

Of 1405 initial hits, 19 studies were eligible including a total of 55 859 participants. Subjects with higher SUA levels had significantly higher BMD values for the spine (six studies; SMD = 0·29; 95% CI: 0·22-0·35; I2 = 47%), total hip (seven studies; SMD = 0·29; 95% CI: 0·24-0·34; I2 = 33%) and femoral neck (six studies; SMD = 0·25; 95% CI: 0·16-0·34; I2 = 71%). Simple correlation analyses substantially confirmed these findings. An increase of one standard deviation in SUA levels reduced the number of new fractures at follow-up (three studies; HR = 0·83; 95% CI: 0·74-0·92; I2 = 0%). No significant differences between men and women emerged, although data about women were limited.

CONCLUSIONS

Hyperuricemia was found independently associated with BMD and fractures, supporting a protective role for uric acid in bone metabolism disorders.

Serum uric acid as prognostic marker of coronary heart disease (CHD)

BACKGROUND

A substantial body of epidemiological and experimental evidence suggests the significance of serum uric acid as an important and independent risk factor of cardio vascular and renal diseases especially in patients with diabetes mellitus, hypertension. Hyperuricemia is a risk factor of coronary heart disease. Several studies showed positive association between hyperuricemia and CHD risk factors.

OBJECTIVE

To analyze the serum uric acid levels in patients with diabetes and hypertension, which helps in understanding its role as prognostic marker of coronary heart disease.

METHOD

The study was conducted in population of Wadi-Al Dawasir (K.S.A.) aged 20-80 years through random sampling from October 2012 to June 2013. It included 250 samples and the cases were categorized into diabetic and hypertensive. In the cases, purely hypertensive were 52, diabetic were 57 and mixed group included both diabetic and hypertensive patients 65. Fasting blood was collected to analyze lipid profile which included (total cholesterol, triglycerides, high density lipoprotein, low density lipoprotein) and serum uric acid in association with age and heredity was also studied. Patient demographics were recorded.

RESULTS

The study revealed significant association of serum uric acid (p<0.014*) and total cholesterol (p<0.007**) triglycerides (p<0.009**) low density lipoprotein (p<0.044*) in hypertensive group. Serum uric acid levels in the mixed group patients with diabetes and hypertension reported serum uric acid (p<0.0037), total cholesterol (p<0.089+) proved to have increased risk of coronary heart disease. When compared to controls (non-diabetic p<0.529) and (non-hypertensive p<0.021*) with respect to serum uric acid levels show the magnitude of risk to coronary heart disease. With progressing age the association of lipid profile and serum uric acid reported (p<0.001**) in diabetics.

CONCLUSION

Significant correlations were found between serum uric acid and risk factors for CHD. This is first study of its kind in this region of K.S.A., which helps the community to understand the role of serum uric acid in coronary heart disease, justifies the objective of research in taking preventive measures to combat the deleterious effect of coronary heart disease. Prevention and early detection of elevated uric acid in both hypertensive and diabetic patients could serve as effective investigative tool in reducing coronary heart disease.

The Human and Economic Burden of Difficult-to-Treat Gouty Arthritis

Gouty arthritis, one of the most painful and common forms of adult arthritis, is caused by monosodium urate crystal deposits in joints, most often in the lower extremities. Crystals trigger an inflammatory response leading to acute flares characterized by a rapid onset of pain, warmth, swelling, and redness in involved joints. Over time, continued monosodium urate crystal deposits and inflammation can lead to chronic tophaceous gout that result in bone erosion, progressing to joint destruction and significant disability. The goal of therapy in an acute gout flare is prompt and safe termination of pain and inflammation. Acute gouty arthritis is usually treated with nonsteroidal anti-inflammatory drugs, colchicine, or corticosteroids. However, for a growing number of patients, current standard treatments are ineffective or are contraindicated, largely due to the presence of comorbidities. Gouty arthritis can have a major negative impact of health-related quality of life, especially in patients with difficult-to-treat disease, as revealed by recent studies comparing health-related quality of life with that of the general population. Additionally, gouty arthritis also constitutes an important economic burden through absence from work and medical costs. This burden is even greater in patients with difficult-to-treat disease.

Gender differences for uric acid as predictor of hard events in patients referred for coronary angiography

Aim: To assess gender differences in uric acid (UA) as predictor for hard events (HE, mortality and nonfatal myocardial infarction) in a large cohort of patients referred for coronary angiography. Design & patients: 3020 inpatients (2177 males, age: 68 ± 9 years, mean ± SD) were retrospectively studied, collecting data from the Institute electronic databank which included demographic, clinical, instrumental and follow-up data. Results: Although the Kaplan–Meier survival estimates showed a significantly worst outcome in female patients, high UA did not remained a significant predictor for HE after adjustment. Moreover, UA correlated with antioxidant capacity in both sexes. Conclusion: Hyperuricemia was not an independent risk for HE, and being correlated with antioxidant capacity, its elevation appears more likely compensatory than causative for HE.

Uric Acid for Cardiovascular Risk: Dr. Jekyll or Mr. Hide?

Uric acid (UA) is a potent endogenous antioxidant. However, high concentrations of this molecule have been associated with cardiovascular disease (CVD) and renal dysfunction, involving mechanisms that include oxidative stress, inflammatory processes, and endothelial injury. Experimental and in vitro results suggest that this biomarker behaves like other antioxidants, which can shift from the physiological antioxidant action to a pro-oxidizing effect according to their level and to microenvironment conditions. However, data on patients (general population or CAD cohorts) are controversial, so the debate on the role of hyperuricemia as a causative factor for CVD is still ongoing. Increasing evidence indicates UA as more meaningful to assess CVD in women, even though this aspect needs deeper investigation. It will be important to identify thresholds responsible for UA “biological shift” from protective to harmful effects in different pathological conditions, and according to possible gender-related differences. In any case, UA is a low-tech and inexpensive biomarker, generally performed at patient’s hospitalization and, therefore, easily accessible information for clinicians. For these reasons, UA might represent a useful additive tool as much as a CV risk marker. Thus, in view of available evidence, progressive UA elevation with levels higher than 6 mg/dL could be considered an “alarm” for increased CV risk.

Purines: forgotten mediators in traumatic brain injury

Recently, the topic of traumatic brain injury has gained attention in both the scientific community and lay press. Similarly, there have been exciting developments on multiple fronts in the area of neurochemistry specifically related to purine biology that are relevant to both neuroprotection and neurodegeneration. At the 2105 meeting of the National Neurotrauma Society, a session sponsored by the International Society for Neurochemistry featured three experts in the field of purine biology who discussed new developments that are germane to both the pathomechanisms of secondary injury and development of therapies for traumatic brain injury. This included presentations by Drs. Edwin Jackson on the novel 2',3'-cAMP pathway in neuroprotection, Detlev Boison on adenosine in post-traumatic seizures and epilepsy, and Michael Schwarzschild on the potential of urate to treat central nervous system injury. This mini review summarizes the important findings in these three areas and outlines future directions for the development of new purine-related therapies for traumatic brain injury and other forms of central nervous system injury. In this review, novel therapies based on three emerging areas of adenosine-related pathobiology in traumatic brain injury (TBI) were proposed, namely, therapies targeting 1) the 2',3'-cyclic adenosine monophosphate (cAMP) pathway, 2) adenosine deficiency after TBI, and 3) augmentation of urate after TBI.

Effects of non-supervised low intensity aerobic excise training on the microvascular endothelial function of patients with type 1 diabetes: a non-pharmacological interventional study

Background

The aim of the present study was to evaluate changes in microvascular density and reactivity in patients with type 1 diabetes (T1D) resulting from low intensity chronic exercise training.

Methods

This study included 22 (34 ± 7 years) consecutive outpatients with T1D and disease duration > 6 years. We used intravital video-microscopy to measure basal skin capillary density and capillary recruitment using post-occlusive reactive hyperemia (PORH) in the dorsum of the fingers. Endothelium-dependent and -independent vasodilation of the skin microcirculation was evaluated in the forearm with a laser Doppler flow monitoring (LDF) system in combination with acetylcholine and sodium nitroprusside iontophoresis, PORH and local thermal hyperemia.

Results

The basal mean capillary density (MCD) after exercise training was significantly higher than before exercise (134 ± 25 vs. 119 ± 19 capillaries/mm², respectively; P = 0.0013). MCD during PORH was also higher after exercise (140 ± 26 vs. 121 ± 24 capillaries/mm², respectively; P < 0.0001). Endothelium-dependent capillary recruitment during PORH was also significantly higher after exercise (140 ± 26 vs. 134 ± 25 capillaries/mm², respectively; P < 0.0012). There were no significant changes in skin microvascular reactivity after exercise as investigated using LDF.

Conclusions

Our results showed that low intensity aerobic exercise, performed four times per week for 12 weeks by patients with T1D, induces significant increases in microvascular density and endothelial-dependent capillary reactivity.

Trial registration

ClinicalTrials.gov NCT02441504. Registered 7 May 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0191-9) contains supplementary material, which is available to authorized users.

Association of ABCG2 rs2231142-A allele and serum uric acid levels in male and obese individuals in a Han Taiwanese population

BACKGROUND/PURPOSE

Recent studies suggest that hyperuricemia is a potential risk factor for cardiovascular disease (CVD). Hyperuricemia is highly heritable and is associated with sex and body weight. Previous genome-wide association studies have found that the ABCG2 single nucleotide polymorphism (SNP) rs2231142 is an important genetic factor for increased uric acid (UA) levels, and the degree of association between rs2231142 and hyperuricemia is affected by both sex and ethnicity. This investigation aimed to analyze the association between ABCG2 polymorphisms and UA levels, as well as their interactions with sex and obesity in Taiwanese.

METHODS

Two genetic polymorphisms around the ABCG2 gene were genotyped in 459 patients.

RESULTS

After adjusting for clinical covariates, the rs2231142 SNP was found significantly associated with UA levels using a dominant inheritance model. Patients carrying the rs2231142-A allele had a higher frequency of hyperuricemia than those with the rs2231142-CC allele. Subgroup analysis revealed an association of rs2231142 with UA levels in male or obese patients, and there was no association in nonobese female patients.

CONCLUSION

The rs2231142 SNP is associated with serum UA levels and hyperuricemia in Taiwanese patients and it occurs predominantly in male or obese patients. Hyperuricemia might be controlled differently by sex and obesity.

Association between low dietary zinc and hyperuricaemia in middle-aged and older males in China: a cross-sectional study

OBJECTIVE

To examine the associations between dietary zinc intake and hyperuricaemia.

DESIGN

Cross-sectional study.

SETTING

This study was conducted in a health examination centre of China.

PARTICIPANTS

A total of 5168 middle-aged and older participants (aged 40 years or above) (2697 men and 2471 women) were included.

OUTCOME MEASURES

Dietary zinc intake was assessed using a validated semiquantitative food frequency questionnaire. Hyperuricaemia was defined as uric acid ≥416 µmol/L for males and ≥360 µmol/L for females.

RESULTS

For males, the prevalence of hyperuricaemia was 22.9%. After adjusting for age, body mass index (BMI) and energy intake, the ORs were 0.68 (95% CI 0.45 to 0.92) in the second quintile, 0.63 (95% CI 0.45 to 0.89) in the third quintile, 0.68 (95% CI 0.46 to 1.00) in the fourth quintile and 0.55 (95% CI 0.35 to 0.87) in the fifth quintile comparing the lowest quintile of Zn intake, respectively (p for trend=0.03). In the multivariable adjusted model, the relative odds of hyperuricaemia were significantly decreased by 0.71 times in the second quintile of zinc intake (OR 0.71, 95% CI 0.52 to 0.98), 0.64 times in the third quintile (OR 0.65, 95% CI 0.44 to 0.94) and 0.55 times in the fifth quintile (OR 0.56, 95% CI 0.32 to 0.97) compared with those in the lowest quintile, and p for trend was 0.064. For females, the prevalence of hyperuricaemia was 10.0%, and unadjusted, minimally adjusted as well as multivariable adjusted ORs all suggested no significant association between dietary zinc intake and hyperuricaemia.

CONCLUSIONS

The findings of this cross-sectional study indicated that dietary zinc intake was inversely associated with hyperuricaemia in middle-aged and older males, but not in females. The association was significant after considering the influence of age, BMI and energy intake, and after that, minimum adjustment remained independent of further confounding factors such as vitamin C intake, alcohol drinking status and nutrient supplementation.

Consensus Meeting on "Uric Acid and Cardiovascular Risk" held at University Magna Graecia, Catanzaro, Italy, May 2014. Publication of the Proceedings as a special issue in the International Journal of Cardiology

Introduction to a special supplement issue on the importance of uric acid in cardiovascular disorders.

Uric acid and coronary artery disease: An elusive link deserving further attention

Uric acid is the final product of purine metabolism. Classically it is recognized as the cause of gouty arthritis and kidney stones. Western civilization has increased serum levels of uric acid which is no longer considered a benign plasma solute. It has been postulated and recently demonstrated that it can penetrate cell membrane and exerts damaging intracellular actions such as oxidation and inflammation. These observations have stimulated several epidemiological researches suggesting that hyperuricemia is linked or even provokes hypertension and coronary artery disease. In this review we summarize the current evidences regarding uric acid which contribute in the pathophysiology of coronary artery disease.

Relationship of blood pressure with some cardiovascular disease risk factors in a rural population of Plateau State, North Central Nigeria

Background:

Hypertension is associated with certain cardiovascular disease (CVD) risk factors which vary from one place to the other depending on community sophistication. We decided to obtain the situation as it affects this rural Nigerian community to be in an evidence-based position to initiate individual and group prevention strategies.

Design:

Cross-sectional population survey.

Materials and Methods:

We surveyed for CVD risk factors among subjects 15 years and above in this rural community using a questionnaire requesting personal, medical and anthropometric information. One in three of them were randomly assigned to laboratory investigations.

Results:

Of the 840 subjects studied, 25% were males. The population mean age was 45.5 (18.2) standard deviation (SD), with 1.8% smokers and 4.1% using alcohol. Systolic blood pressure (SBP) correlated with age, body mass index (BMI), total cholesterol (TC) and uric acid (UA); while diastolic blood pressure (DBP) correlated with age, BMI, TC, UA and atherogenic index (AI). SBP and DBP improved with exercise but not salt intake. The local seasonings used in cooking had no impact on blood pressure.

Conclusion:

To reduce cardiovascular morbidity in this and probably other rural sub-Saharan African communities, BMI, TC, UA and salt intake in diet should be targeted for reduction. Physical activity should be encouraged. Interestingly, these fall into the sphere of healthy lifestyle which should be encouraged and re-inforced.

Gout and a Subsequent Increased Risk of Erectile Dysfunction in Men Aged 64 and Under: A Nationwide Cohort Study in Taiwan

Objective.

Few studies have examined the relationship between gout and erectile dysfunction (ED). We investigated whether patients with gout exhibited an increased risk of ED.

Methods.

This longitudinal nationwide cohort study investigated the incidence and risk of ED in 19,368 men with gout who were newly diagnosed between January 2002 and December 2008. A total of 77,472 controls without gout were randomly selected from the general population and frequency-matched according to age and sex. The patients were followed up from the date on which they were included in the study cohort to the date of an ED event, censoring, or December 31, 2010. We conducted the Cox proportional hazard model to estimate the effects of gout on ED risk including age and comorbidities.

Results.

The gout cohort exhibited a 1.21-fold adjusted HR of subsequent ED development compared with the non-gout cohort (95% CI 1.03–1.44). The incidence of ED increased with age in both cohorts and was higher among the patients in the gout cohort than among those in the non-gout cohort. Compared to the patients without gout and comorbidities, the patients with both gout and any type of comorbidity exhibited a 2.04-fold risk of developing ED (95% CI 1.63–2.57). Further, the patients with gout who had numerous comorbidities exhibited the dose-response effect in developing ED.

Conclusion.

This nationwide cohort study revealed that ED risk is significantly higher in patients with gout than in the general population.

Association Between Colchicine and Risk of Diabetes Among the Veterans Affairs Population With Gout

PURPOSE

This study aimed to determine the association between colchicine use and the incidence of diabetes in a cohort of patients with gout.

METHODS

This is a retrospective study of 27,876 adults with gout identified via the Veterans Integrated Services Network 16 data warehouse. Patients had up to 11 years of follow-up (January 1999 through December 2010). The final study sample consisted of 1046 pairs of 1:1 propensity score-matched patients from the colchicine treated and control cohorts. Time to first diabetes development since the first gout diagnosis was modeled.

RESULTS

After the propensity score matching, the 12-month baseline variables (eg, age, sex, race, index year, body mass index, serum uric acid, antigout drug use, and health care use) were comparable between the matched cohorts (P > 0.05 for all). Among the 1046 matched pairs, 234 patients who had taken colchicine and 224 patients who had never taken colchicine developed diabetes; the incidence rates were 38.95 and 39.02 per 1000 patient-years, respectively. In Poisson and Cox proportional hazards regression, the risk of incident diabetes was reduced with increased duration of colchicine use, but the difference was not statistically significant (P > 0.05). In a time-varying Cox proportional hazards model, the hazard ratio for incident diabetes among patients who had taken colchicine was 0.877 (95% CI, 0.662-1.163; P = 0.362) compared with those who had not taken colchicine.

CONCLUSION

This study suggests a possible duration- or dose-related association between colchicine use and reduced risk of diabetes in adults with gout even though the risk reduction was not significant. Further studies are needed to confirm findings from this study.