Serum uric acid and metabolic risk

Uric acid could be a marker of cardiometabolic risk and disease severity in children with juvenile idiopathic arthritis

In addition to disease-specific complications, juvenile idiopathic arthritis (JIA) has been linked to metabolic impairments in adults. Recent data supported the usefulness of uric acid (UA) as risk factor for cardiometabolic derangements. Given the lack of pediatric evidence in this field, we aimed to explore this association in a cohort of children diagnosed with JIA. We retrospectively evaluated 113 children diagnosed with JIA classified according to the International League of Association for Rheumatology (ILAR) criteria attending our Rheumatology Clinic. Both clinical and biochemical assessments were performed. Participants were stratified in four groups according to quartiles of serum UA. Disease activity was calculated by the Juvenile Arthritis Disease Activity Score 10 (JADAS-10) joint reduced count, and cut-offs for disease states were applied. Patients belonging to the highest UA quartile showed higher serum triglycerides, total cholesterol, creatinine, and glucose levels (p = 0.01, p = 0.025, p = 0.04, and p = 0.005, respectively) and lower HDL cholesterol values (p < 0.0001) than subjects belonging to the lowest quartiles. Ferritin, erythrocyte sedimentation rate levels, and age at disease onset did not significantly differ across UA quartiles (all p > 0.05). As activity disease index, JADAS-10 score significantly increased across UA quartiles (p = 0.009).

CONCLUSION

Children with JIA presented with a worse cardiometabolic profile and a greater disease severity across UA quartiles. Our findings suggest that in clinical practice, UA might represent a useful marker of cardiometabolic risk and disease severity in children with JIA.

WHAT IS KNOWN

• JIA has been linked to metabolic derangements in adulthood. • UA has been recognized as a marker of cardiometabolic risk both in adults and children.

WHAT IS NEW

• Children with JIA belonging to the highest UA quartile showed a worse cardiometabolic profile and a greater disease severity. • UA might represent a helpful marker not only of cardiometabolic risk but also of disease severity in children with JIA.

An Unusual Case of Kidney Injury in a Young Woman with a Connective Tissue Disease

A 32-year-old female was admitted to our institution with thrombocytopenia, fever, serositis, hepatosplenomegaly, diffuse lymphadenopathy, and renal insufficiency. A diagnosis of systemic lupus erythematosus was made. Due to recalcitrant thrombocytopenia, serositis, and renal insufficiency methylprednisolone was prescribed in high doses. In addition to proteinuria and hematuria, she was found to have uric acid crystals in her urinalysis. A serum uric acid was found elevated at 18 mg/dL. Rasburicase infusions were started. Within 5 days of commencing rasburicase and continuing high-dose methylprednisolone, her serum creatinine normalized and proteinuria resolved. The microhematuria disappeared within 2 weeks of beginning rasburicase. The rapid reversal of renal insufficiency and all urinary abnormalities after the start of rasburicase infusions suggests that the renal injury was most likely due to uric acid-mediated renal injury and not lupus nephritis. Our case illustrates the co-occurrence of 2 distinct clinical entities, one common for the patient's age, sex, and foremost clinical findings, while the other uncommon and unexpected, but both associated to kidney injury. Clinicians must be aware that careful evaluation of symptoms and laboratory tests is needed to make a thorough differential diagnosis and provide the right treatment at the most opportune moment.

Serum Uric Acid and Kidney Disease Measures Independently Predict Cardiovascular and Total Mortality: The Uric Acid Right for Heart Health (URRAH) Project

Background: Serum uric acid predicts the onset and progression of kidney disease, and the occurrence of cardiovascular and all-cause mortality. Nevertheless, it is unclear which is the appropriate definition of hyperuricemia in presence of chronic kidney disease (CKD). Our goal was to study the independent impact of uric acid and CKD on mortality. Methods: We retrospectively investigated 21,963 patients from the URRAH study database. Hyperuricemia was defined on the basis of outcome specific cut-offs separately identified by ROC curves according to eGFR strata. The primary endpoints were cardiovascular and all-cause mortality. Results: After a mean follow-up of 9.8 year, there were 1,582 (7.20%) cardiovascular events and 3,130 (14.25%) deaths for all causes. The incidence of cardiovascular and all-cause mortality increased in parallel with reduction of eGFR strata and with progressively higher uric acid quartiles. During 215,618 person-years of follow-up, the incidence rate for cardiovascular mortality, stratified based on eGFR (>90, between 60 and 90 and <60 ml/min) was significantly higher in patients with hyperuricemia and albuminuria (3.8, 22.1 and 19.1, respectively) as compared to those with only one risk factor or none (0.4, 2.8 and 3.1, respectively). Serum uric acid and eGFR significantly interact in determining cardiovascular and all-cause mortality. For each SUA increase of 1 mg/dl the risk for mortality increased by 10% even after adjustment for potential confounding factors included eGFR and the presence of albuminuria. Conclusions: hyperuricemia is a risk factor for cardiovascular and all-cause mortality additively to eGFR strata and albuminuria, in patients at cardiovascular risk.

Higher Serum Uric Acid Level Predicts Non-alcoholic Fatty Liver Disease: A 4-Year Prospective Cohort Study

Background: Non-alcoholic fatty liver disease (NAFLD) has become a serious disease affecting people's health in the world. This article studies the causal relationship between NAFLD and serum uric acid (SUA) levels. Methods: During the 4 years of follow-up in a fixed cohort that was established in 2014, 2,832 follow-up subjects without NAFLD were finally included in this study. The study population was divided into four groups according to baseline SUA levels. Cox hazard regression model and Kaplan-Meier survival curves analysis were used to predict risk factors of NAFLD. The receiver operating characteristic curve analyses were used to determine SUA cutoffs for predicting NAFLD. Results: The cumulative prevalence rates of NAFLD were 33.97% (962/2,832), 38.93% (758/1,947) in males and 23.05% (204/885) in females. The results showed that males had a higher incidence of NAFLD (χ² = 68.412, P = 0.000). The Cox regression analysis disclosed that the hazard ratios of NAFLD [95% confidence interval (CI)] were 1.431 (95% CI, 1.123~1.823), 1.610 (95% CI, 1.262-2.054), and 1.666 (95% CI, 1.287-2.157) across the second to the fourth quartile of SUA adjusted for other confounders. The SUA cutoffs, sensitivity, specificity, and area under the curve (AUC) (95% CI) were ≥288.5 μmol/L, 75.5, 46.5%, 0.637(0.616-0.658), respectively, for total; ≥319.5 μmol/L, 65.8%, 48.4%, 0.590 (0.564-0.615), respectively, for males; and ≥287.5 μmol/L, 51.0%, 75.6%, 0.662 (0.619-0.704), respectively, for females. Kaplan-Meier survival curves revealed that individuals with higher SUA level had an increased risk of NAFLD in comparison to lower SUA level (P = 0.000). Conclusion: Serum uric acid is positively correlated with NAFLD, and elevated SUA level can be used as an independent predictor for NAFLD.

Hyperuricemia in Asian psoriatic arthritis patients

AIM

It is generally accepted that hyperuricemia is commonly associated with psoriatic arthritis (PsA). However, variations in ethnicity, diet and habitat may contribute to differences in prevalence and risk factors for hyperuricemia in PsA patients. Moreover, Asian specific data is deficient. The primary objective of the present study was to determine the prevalence of hyperuricemia among PsA patients. The secondary objective was to explore its associated risk factors.

METHODS

This was a multi-center, cross-sectional observational study of 160 PsA patients from local Rheumatology clinics. Serum uric acid (SUA) level and other clinical parameters were measured and hyperuricemia was defined as SUA level greater or equal to 360 umol/L in females and 420 umol/L in males.

RESULTS

Forty-nine of 160 patients (30.6%) had hyperuricemia, of which 32 were men, 17 were women. Among those with hyperuricemia, mean SUA level was 500.7 ± 95.9 umol/L and 427.8 ± 83.1 umol/L in males and females, respectively. Univariate analysis found: (i) overweight status; (ii) obesity; (iii) Psoriasis Area and Severity Index; (iv) body surface area; (v) severe skin involvement, as being potentially associated with hyperuricemia. Regression model identified overweight status increased the likelihood of hyperuricemia in PsA, with an odds ratio of 4.4 (95% CI: 2.0-9.5). Furthermore, there was moderately positive correlation (r = 0.37) between body mass index (BMI) and SUA level. No associations were found between arthritis conditions and duration, lipid profile, creatinine clearance; and hyperuricemia.

CONCLUSION

A significant proportion of PsA patients had asymptomatic hyperuricemia. It was closely related with BMI, which represented metabolic dysregulation; but not with severity of skin disease, joint involvement or renal function.

Weight Loss, Xanthine Oxidase, and Serum Urate Levels: A Prospective Longitudinal Study of Obese Patients

OBJECTIVE

The mechanisms by which weight loss decreases serum uric acid (SUA) levels are poorly known. We aimed to investigate the role played by xanthine oxidase (XOD), metabolic status, and low-grade inflammation in decreased SUA levels induced by weight loss in obese patients.

METHODS

Data were from a series of consecutive patients with severe obesity involved in a bariatric surgery program. Measurements of body composition and biologic samples were obtained before surgery and 6 months after surgery.

RESULTS

Among the 154 patients (mean ± SD age 41.0 ± 12.3 years, body mass index [BMI] 47.8 ± 7.2 kg/m(2) , 81% female), the mean ± SD weight loss at 6 months was 31.3 ± 7.8 kg. Reduction in SUA levels was modest (-10%): 4.98 ± 1.21 mg/dl at 6 months versus 5.52 ± 1.33 mg/dl at baseline (P < 0.001). The decrease in SUA levels was greatest (-18%) in hyperuricemic patients (n = 48). In these patients, circulating XOD activity decreased with weight loss (P < 0.0001). Multiple linear regression analysis revealed decreased SUA levels associated with decreased triglyceride levels (P = 0.0001) and BMI (P = 0.02) but not XOD activity, adipokine levels (leptin and adiponectin), insulin resistance, or levels of inflammatory variables (interleukin 6, orosomucoid, fibrinogen, and high-sensitivity C-reactive protein).

CONCLUSION

In obese patients, weight loss was associated with a decrease in both SUA levels and XOD activity. Our findings suggest that reduced SUA levels are not mediated by decreased XOD activity or improved insulin resistance but could be partly due to a reduction in triglyceride levels.

Correlations of non-alcoholic fatty liver disease and serum uric acid with subclinical atherosclerosis in obese Chinese adults

BACKGROUND

Existing evidence about the associations of non-alcoholic fatty liver disease (NAFLD) and serum uric acid (SUA) with subclinical atherosclerosis is controversial. The aim of the present study was to examine the associations of NAFLD and SUA with subclinical atherosclerosis.

METHODS

In the present cross-sectional study, 1354 obese adults underwent hepatic ultrasonography and arteriosclerosis detection. Indices of subclinical atherosclerosis were brachial-ankle pulse wave velocity (ba-PWV) and the ankle-brachial index (ABI). Linear regression using multivariable fractional polynomial (MFP) modeling was used to examine independent associations of NAFLD and SUA with a-PWV and ABI.

RESULTS

Compared with controls, mean (± SD) ba-PWV was significantly higher in subjects with NAFLD (1534 ± 292 vs 1433 ± 259 cm/s; P < 0.001) and hyperuricemia (HUA; 1519 ± 275 vs 1476 ± 287 cm/s; P = 0.007). After adjustment for sociodemographic and lifestyle factors, NAFLD and SUA were both positively related to ba-PWV (β = 0.120 and 0.064, respectively; P < 0.05 for both). With further adjustment for insulin resistance and components of metabolic syndrome (MetS), the positive correlations were no longer significant (β = 0.017 and 0.006; P > 0.05 for both). In addition, NAFLD, but not SUA, was negatively correlated with ABI (β = -0.073; P = 0.015). Using MFP modeling, the best fractional polynomial (FP) transformation model showed that non-linear transformations were appropriate for two variables in their relationship with ba-PWV, namely age and fasting insulin as first-degree FP transformations (age³ and 1/insulin^0.5 , respectively).

CONCLUSIONS

Neither NAFLD nor SUA was related to ba-PWV with increases in insulin resistance and MetS, but NAFLD was independently and negatively correlated with ABI.

Recent advances in understanding and managing gout

Gout is the most common crystal arthropathy and the leading cause of inflammatory arthritis. It is associated with functional impairment and, for many, a diminished health-related quality of life. Numerous studies have demonstrated the impact of gout and its associated conditions on patient morbidity and mortality. Unfortunately, gout remains under-diagnosed and under-treated in the general community. Despite major advances in treatment strategies, as many as 90% of patients with gout are poorly controlled or improperly managed and their hyperuricemia and recurrent flares continue. The introduction of novel urate-lowering therapies, new imaging modalities, and a deeper understanding of the pathogenesis of gout raise the possibility of better gout care and improved patient outcomes. Here, we spotlight recent advances in the diagnosis and management of gout and discuss novel therapeutics in gout treatment.

Serum uric acid is independently and linearly associated with risk of nonalcoholic fatty liver disease in obese Chinese adults

The present study aimed to explore the independent association and potential pathways between serum uric acid (SUA) and nonalcoholic fatty liver disease (NAFLD). 1365 community-living obese Chinese adults who received hepatic ultrasonography scanning were included. The prevalence rates of NAFLD were 71.5% for men and 53.8% for women. Compared with controls, NAFLD subjects showed significantly increased SUA levels (333.3 ± 84.9 v.s. 383.4 ± 93.7 μmol/L) and prevalence rate of hyperuricemia (HUA) (25.7% v.s. 47.3%, p < 0.001). After adjustment for insulin resistance (IR), components of metabolic syndrome (MetS) and other potential confounders, elevated SUA is independently associated with increased risk of NAFLD, with the adjusted OR of 1.528–2.031 (p < 0.001). By using multivariable fractional polynomial (MFP) modeling, the best FP transformation model shows that SUA was independently and linearly associated with risk of NAFLD. The one-pathway model by using structural equation modeling (SEM) about the relationships among SUA, IR, components of metabolic syndrome and NAFLD fits well (χ² = 57.367, p < 0.001; CFI = 0.998; TLI = 0.992; and RMSEA = 0.048) and shows SUA might increase the risk of NAFLD directly besides of the indirect effects through increasing fasting insulin, blood pressure, triglyceride and decreasing HDL-C levels. Our results imply that elevated SUA may play an important role in NAFLD pathogenesis.

2016 updated EULAR evidence-based recommendations for the management of gout

Background

New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations.

Methods

The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach.

Results

Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended.

Conclusions

These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.

Serum antioxidant levels associated with subcortical ischemic vascular disease

OBJECTIVE

We aimed to examine changes in serum bilirubin and uric acid (ua) levels in subcortical ischemic vascular disease (Sivd). in addition, we investigated if altered serum bilirubin and ua levels correlate with the subtypes of Sivd as well as the severity of leukoaraiosis (la).

METHODS

this cross-sectional study included 1098 consecutive patients with slight symptoms, such as dizziness, vertigo etc. according to magnetic resonance imaging (Mri) appearances, they were divided into either Sivd group or controls (Cn), and the Sivd group was further grouped in lacunar infarction (li) and la subtypes, as well as different grades. Serum bilirubin and ua levels were determined by the vanadate oxidase method and enzymatic method respectively, after at least an eight hour overnight fasting, in all subjects.

RESULTS

the bilirubin level was obviously lower while the ua level was significantly higher in the Sivd group when compared with the controls. Moreover, the la subgroup presented more significant changes in bilirubin and ua when compared to the li subgroup in both males and females. the correlation was positive between the ua levels and the la severity (r=0.134, p=0.006). Multivariate regression analysis revealed that the odds ratio (95% Ci) for Sivd in the lowest tertile of total bilirubin (tbil<9.58 μmol/l) and highest tertile of ua (ua>339 μmol/l) were 2.702(1.936-3.770) and 2.135(1.521-2.996) respectively after adjusting for confounding variables.

CONCLUSION

Serum bilirubin levels were lower, whereas ua levels were higher in Sivd patients when compared with controls in both males and females, especially in la patients. Moreover, serum ua levels positively correlated to la severity.

The Power of Serum Uric Acid in Predicting Metabolic Syndrome Diminishes With Age in an Elderly Chinese Population

OBJECTIVES

Although serum uric acid (sUA) is not a criterion for diagnosing metabolic syndrome (MetS), many studies have identified a positive association between sUA and MetS in patients of various ages and ethnicities. This association has not been fully established in the very elderly.

DESIGN

Cross-sectional and longitudinal study.

SETTING AND PARTICIPANTS

A total of 18,906 Chinese elderly aged 65 and older undergoing routine health checkups in Taiwan were enrolled.

MEASUREMENTS

Modified Adult Treatment Panel III criteria were used to define MetS. All participants were further divided into nine groups with gender specification according to age (the young-old, 65 to 74; old-old, 75 to 84; and oldest-old, 85 and over) and sUA concentration tertile (males: sUAG1, <5.7 mg/dL; sUAG2, 5.7-6.7 mg/dL; and sUAG3, > 6.7 mg/dL; females: sUAG1, <4.9 mg/dL; sUAG2, 4.9-5.9 mg/dL; and sUAG3, > 5.9 mg/dL). A cross-sectional study was first performed to determine the correlation between sUA and MetS and its components. A longitudinal study then excluded subjects with MetS at baseline to explore the risk of MetS according to sUA levels in 3 age groups.

RESULTS

In the cross-sectional study, we observed a graded, positive association between sUA and MetS components that diminished after age 75. Subjects with higher sUA levels had higher odds ratios (OR) for the occurrence of MetS in the young-old and old-old groups of both sexes (P<0.001) except sUAG2 males in the old-old group. However, the association diminished with age and only a higher OR was observed in sUAG2 males in the oldest-old group (OR, 3.38; 95% CI, 1.11-10.30; P = 0.032). In the longitudinal study, the Kaplan-Meier plot showed that higher sUA levels were associated with a higher risk of MetS in the young-old group of both genders (P < 0.001 sUAG3 vs. sUAG1 and sUAG2). Cox regression analysis further confirmed these results (young-old group: sUAG3 HR, 1.90; 95% CI, 1.42-2.54; P < 0.001; old-old group males: HR, 2.20; 95% CI, 1.04-4.65; P = 0.039; young-old females: HR, 1.83; 95% CI, 1.38 - 2.43; P < 0.001).

CONCLUSIONS

Higher sUA levels in the young-old group of Chinese elderly were associated with a higher risk of developing MetS. sUA levels are thus regarded as a potential tool for early diagnosis of MetS. However, this association diminished in those over 75 years of age.

Uric Acid Levels Can Predict Metabolic Syndrome and Hypertension in Adolescents: A 10-Year Longitudinal Study

The relationships between uric acid and chronic disease risk factors such as metabolic syndrome, type 2 diabetes mellitus, and hypertension have been studied in adults. However, whether these relationships exist in adolescents is unknown. We randomly selected 8,005 subjects who were between 10 to 15 years old at baseline. Measurements of uric acid were used to predict the future occurrence of metabolic syndrome, hypertension, and type 2 diabetes. In total, 5,748 adolescents were enrolled and followed for a median of 7.2 years. Using cutoff points of uric acid for males and females (7.3 and 6.2 mg/dl, respectively), a high level of uric acid was either the second or third best predictor for hypertension in both genders (hazard ratio: 2.920 for males, 5.222 for females; p<0.05). However, uric acid levels failed to predict type 2 diabetes mellitus, and only predicted metabolic syndrome in males (hazard ratio: 1.658; p<0.05). The same results were found in multivariate adjusted analysis. In conclusion, a high level of uric acid indicated a higher likelihood of developing hypertension in both genders and metabolic syndrome in males after 10 years of follow-up. However, uric acid levels did not affect the occurrence of type 2 diabetes in both genders.

Liver Fat Content Is Associated with Elevated Serum Uric Acid in the Chinese Middle-Aged and Elderly Populations: Shanghai Changfeng Study

Background and Aims

Although many studies have indicated a relationship between nonalcoholic fatty liver disease (NAFLD) and hyperuricemia, a few studies specifically examining the effects of the severity of liver fat content (LFC) on serum uric acid (SUA) and the presence of hyperuricemia because of the limitation of the examination methods for NAFLD. In this study, we investigate the relationship between the NAFLD and SUA levels in the Chinese population using standardized quantitative ultrasound.

Methods

A community-based study was conducted from May 2010 to December 2012. A total of 4,305 people aged 45 years and above without excessive drinking were enrolled. A standard interview and anthropometric and laboratory blood parameters were collected for each person. The standardized ultrasound hepatic/renal ratio and hepatic attenuation rate was used to quantify LFC.

Results

The prevalence of NAFLD and hyperuricemia was 33.1% and 17.1%, respectively. A total of 23.5% of the NAFLD subjects had hyperuricemia, and their SUA was higher than that of non-NAFLD subjects (327.2±76.8 vs 301.9±77.4 μmol/L, P<0.001). The LFC was positively correlated with SUA (r = 0.130, P<0.001) and an independent factor for SUA (standardized β = 0.054, P<0.001). The OR for the presence of hypreuricemia was 1.175 (95% CI 1.048–1.318; P<0.001) with a 1 SD increase in the log LFC. LFC greater than 10% was related to elevated SUA and an increased presence of hyperuricemia.

Conclusions

LFC accumulation was associated with an increase in the prevalence of hyperuricemia and elevated SUA in our community-based population. LFC greater than 10% is related to the risk for hyperuricemia.

Psoriasis, psoriatic arthritis and risk of gout in US men and women

BACKGROUND AND OBJECTIVE

Individuals with psoriasis have increased blood levels of uric acid. However, there is no prospective data on the association between psoriasis and uric acid levels and subsequent development of gout. In this study, we examined the risk of gout among individuals with psoriasis and psoriatic arthritis (PsA) in two cohorts of men and women, the Health Professionals Follow-up Study (HPFS) (1986-2010) and Nurses' Health Study (NHS) (1998-2010).

METHODS

27 751 men and 71 059 women were included in the analysis. Lifetime history of physician-diagnosed incident psoriasis and PsA was confirmed by validated supplementary questionnaires. Incident gout diagnoses were confirmed based on the American College of Rheumatology survey criteria. We used Cox proportional hazards models controlling for potential risk factors to calculate the HRs with 95% CIs of incident gout while simultaneously adjusting for several common risk factors.

RESULTS

We documented 2217 incident cases of gout during follow-up. Psoriasis was associated with an increased risk of subsequent gout with a multivariate HR of 1.71 (95% CI 1.36 to 2.15) in the pooled analysis. Risk of gout was substantially augmented among those with psoriasis and concomitant PsA (pooled multivariate HR: 4.95, 95% CI 2.72 to 9.01) when compared to participants without psoriasis.

CONCLUSIONS

In this prospective study of US women and men, psoriasis and PsA were associated with an increased risk of gout.