The management of hyperuricemia with urate deposition

Antihyperuricemic Effect of Dendropanax morbifera Leaf Extract in Rodent Models

Dendropanax morbifera is a well-known traditional medicine used in China and Korea to treat intestinal disorders, urosis, diuresis, and chronic glomerulonephritis. Hyperuricemia is a metabolic disorder characterized by a high uric acid level in serum due to an imbalance between uric acid production and excretion and causes gout. Recently, the prevalence of hyperuricemia worldwide has been continuously increasing. Xanthine oxidase (XOD) inhibitors (allopurinol (ALP) and febuxostat) and uricosuric agents (benzbromarone and probenecid) are used to treat hyperuricemia clinically. However, because these drugs are poorly tolerated and cause side effects, such as kidney diseases, hepatotoxicity, gastrointestinal symptoms, and hypersensitivity syndrome, only a limited number of drugs are available. We investigated the antihyperuricemic effects of Dendropanax morbifera leaf ethanol extract (DMLE) and its underlying mechanisms of action through in vitro and in vivo studies. We evaluated uric acid levels in serum and urine, and xanthine oxidase (XOD) inhibition activity in the serum and liver tissue of a hyperuricemic rat model of potassium oxonate (PO)-induced hyperuricemic rats. In vitro study, XOD-inhibitory activity was the lowest among the test substances at the IC50 of ALP. However, the IC50 of DMLE-70 was significantly low compared with that of other DMLEs (p < 0.05). In PO-induced hyperuricemic rats, uric acid (UA) levels in serum and urine were significantly reduced in all DMLE-70 and allopurinol-treated (ALT) groups than in the PC group (p < 0.05). UA levels in urine were lower than those in serum in all DME groups. In PO-induced hyperuricemic rats, DMEE-200 reduced UA concentration in serum and increased UA excretion in the urine. These findings suggest that DMLE exerts antihyperuricemic and uricosuric effects on promoting UA excretion by enhanced secretion and inhibition of UA reabsorption in the kidneys. Thus, DMLE may be a potential treatment for hyperuricemia and gout.

Higher Levels of High-Sensitivity C-Reactive Protein Is Positively Associated with the Incidence of Hyperuricemia in Chinese Population: A Report from the China Health and Retirement Longitudinal Study

Purpose

The aim of the present cohort study was to explore the longitudinal association between high-sensitivity C-reactive protein (CRP) and hyperuricemia in Chinese population. Furthermore, we conducted subgroup analyses to explore this association according to age, sex, and body mass index.

Methods

A total of 5,419 healthy participants were enrolled in the final cohort analysis. The high-sensitivity CRP level was measured by immunoturbidimetric assay. Hyperuricemia was defined as serum uric acid ≥7.0 mg/dL (416 μmol/L) in men and ≥6.0 mg/dL (357 μmol/L) in women. Multivariate logistic regression was used to analyze the association.

Results

During the 4 years follow-up, 474 participants developed hyperuricemia. Compared with participants in the lowest tertile of high-sensitivity CRP, the multivariate-adjusted odds ratio (OR) (95% confidence interval [CI]) for incident hyperuricemia in the highest tertile was 1.36 (1.02, 1.82). In the subgroup analyses, high-sensitivity CRP was positively associated with the incidence of hyperuricemia after multivariate adjustments (P for trend = 0.04) in women. Compared with the women in the lowest tertile of high-sensitivity CRP, the multivariate-adjusted OR (95% CI) in the highest tertile was 1.69 (1.10, 2.66). No statistically significant association was found in other subgroups.

Conclusions

The findings of this prospective cohort study suggest that higher level of high-sensitivity CRP is an independent risk factor for hyperuricemia in Chinese, especially in women.

Management of hyperuricemia in asymptomatic patients: A critical appraisal

While there is consensus on starting urate-lowering therapy (ULT) in cases of symptomatic hyperuricemia, the frequent condition of asymptomatic hyperuricemia (AH) remains a challenge due to differences in the findings of studies that have addressed the issue. Uric acid has anti-oxidant properties, but high levels predispose to gout and may play a role in metabolic syndrome. We systematically evaluated randomized controlled trials (RCTs) addressing ULT in patients with AH, to assess the current evidence. We found broad heterogeneity among the studies (13 RCTs), in terms of study design and population, making findings challenging to interpret and generalize; hard end-points were not assessed. Allopurinol is often prescribed for AH despite the fact that its use is not backed by conclusive evidence from prospective RCTs, nor is it recommended by the guidelines. Its potential benefits, in terms of absolute risk reduction, must be weighed against its potential for harm since it can trigger severe adverse hypersensitivity reactions, sometimes even fatal. RCTs with hard end-points are needed to assess the risk/benefit of lowering uric acid in subjects with AH, particularly as secondary prevention for cardiovascular risk and in patients with different degrees of renal disease. To date, particularly after the result from the CARES trial, preventive treatment of asymptomatic and non-severe hyperuricemia is not recommended.

Association between Eating Away from Home and Hyperuricemia: A Population-Based Nationwide Cross-Sectional Study in China

Hyperuricemia (HU) is a risk factor for different kinds of chronic noncommunicable diseases, and eating away from home (EAFH) may play an important role in their development, which has been ignored greatly so far. This study aimed to investigate the association between EAFH and HU in different models. A cross-sectional study involving 8,322 participants of the China Health and Nutrition Survey (CHNS) was conducted. Logistic regression models were used to analyze the data. We found that participants who consumed more away-from-home food had a higher risk for HU, and the adjusted odds ratio (aOR) and 95% confidence interval (CI) (for each increment in grades of EAFH) were 1.11 (1.02, 1.20) in a multiadjusted model (adjusted for age, gender, province, net individual income, body mass index, smoking, leisure-time physical activities, energy intake, and sleep duration). As for stratified analyses, the aOR (95% CI) of EAFH was 1.12 (1.01, 1.24) for men and 1.06 (0.92, 1.21) for women. Similar results can be found in the middle-aged and obese population, with aOR (95% CI) of EAFH as 1.17 (1.05, 1.30) and 1.15 (1.03, 1.29), respectively. In conclusion, EAFH is positively associated with the prevalence of HU.

Hyperuricemia is associated with intermittent hand joint pain in a cross sectional study of elderly females: The AGES-Reykjavik Study

Background

The debate whether "asymptomatic hyperuricemia" should be treated is still ongoing. The objective of this cross-sectional study was to analyze whether hyperuricema in the elderly is associated with joint pain.

Methods and findings

Participants in the population-based AGES-Reykjavik Study (males 2195, females 2975, mean age 76(6)) answered standardized questions about joint pain. In addition they recorded intermittent hand joint pain by marking a diagram of the hand. In males, no association was found between hyperuricemia and pain. Females however, showed a positive association between hyperuricemia and joint pain at many sites. After adjustment for age, BMI and hand osteoarthritis however, only intermittent hand joint pain (OR 1.30(1.07–1.58), p = 0.008) and intermittent pain in ≥10 hand joints (OR 1.75(1.32–2.31), p<0.001) remained significant. The best model for describing the relationship between serum uric acid levels (SUA) and intermittent hand joint pain in ≥10 joints was non-linear with a cut-off at 372 μmol/L. The attributable surplus number of symptomatic females with SUA ≥372 μmol/L was approximately 2.0% of the study population for those reporting pain in ≥10 hand joints. Next after having severe hand osteoarthritis, SUA ≥372 was an independent predictive factor of intermittent pain in ≥10 hand joints. Intermittent hand joint pain was also an independent risk factor for worse general health description.

Conclusion

Results from this population based study indicate that hyperuricemia in elderly females may be a rather frequent cause of intermittent hand joint pain, often in many joints. The most likely explanation relates to low-grade urate crystal induced inflammation. Our data do not allow for assessment of the severity of symptoms or whether they merit specific treatment, but intermittent hand joint pain was an independent predictor of worse general health. These findings may be an important contribution to the debate on whether hyperuricemia should be treated.

Knowledge and practice in the management of asymptomatic hyperuricemia among primary health care physicians in Jeddah, Western Region of Saudi Arabia

Objectives:

To assess knowledge and practice levels in asymptomatic hyperuricemia (AH) and investigate predictors of urate-lowering therapy (ULT) misprescribing among primary health care (PHC) physicians.

Methods:

A cross-sectional study was conducted among 201 PHC physicians from December 2017 to May 2018. A based clinical guidelines for hyperuricemia management from American Professional Organizations, a semi-structured questionnaire was administered to collect demographic and professional data; knowledge and practice levels in management of AH; and barriers to the management of hyperuricemia and gout, with focus of the misprescribing of ULT in AH. A 2-stage stratified sampling technique was used to select 4 PHC centers were from each of the 5 advisory sectors in Jeddah, Kingdom of Saudi Arabia; and to recruit a minimum of 10 eligible participants per primary health care center (PHCC). Binary logistic regression was used to analyze predictors of ULT misuse in AH.

Results:

Only 32.8% participating physicians had adequate knowledge about AH. Regarding practice, while majority (88.1%) correctly recommended a low-purine diet and lifestyle changes to patients, almost half misprescribed ULT and 10.9% misprescribed non-steroid anti-inflammatory drugs. Lack of knowledge and awareness about guidelines were the most frequently self-reported barriers to adequate practice. Predictors of ULT misuse included the percentage of patients having gout (1-10%: OR=5.40, p=0.047) or receiving ULT (>10-20%: OR=20.02, p=0.001)among patients seen in clinic, attendance of rheumatology conferences (OR=2.55, p=0.017), and having a close relative with hyperuricemia or gout (OR=2.45, p=0.026).

Conclusion:

There are inadequate levels of knowledge regarding AH among Saudi PHC physicians increasing risk of malpractice including misprescription of ULT and anti-inflammatory medications.

Non-pharmacologic measures for gout management in the prospective GOSPEL cohort: Physicians' practice and patients' compliance profiles

OBJECTIVES

Gout management includes non-pharmacological measures (NPM). The main objective of this study was to describe the NPM proposed by physicians and their implementation by patients after 3-6 months. The secondary objective was to identify NPM compliance profiles among these patients.

METHODS

Ancillary observational study using the GOSPEL French cohort of 1003 patients with gout, based on questionnaires for physicians and patients at inclusion and then after 3-6 months. Patients were included by a representative sample of 398 general practitioners (GP) and 109 private-practice rheumatologists. Modifiable risk factors of hyperuricemia and proposed NPM were compared. Patient compliance profiles were identified by multiple correspondence and hierarchical clustering analysis.

RESULTS

The study included 630 patients: 80.7% were obese or overweight, 51% reported excessive alcohol consumption. Physicians identified fewer modifiable risk factors than their real prevalence in the cohort. Physicians proposed NPM to 57% of patients, particularly diet modifications (46.4%). Increasing physical activity (P < 0.0001) was the best followed NPM. The physician's influence in the decision of starting NPM was more frequent among GPs' patients (P = 0.01). Three patients' compliance profiles were identified. "Very good responders" (55.8%) implemented all the proposed NPM. "Good responders" (12.7%) had a more severe disease and followed the proposed NPM, but for alcohol consumption. "Bad responders" (31.5%) did not modify their life style: these were older patients with a very recent gout diagnosis.

CONCLUSION

More personalized care about NPM requires adapting the practitioner's approach to patients' compliance profiles, especially elderly patients with recent gout.

An evidence-based review on urate-lowering treatments: implications for optimal treatment of chronic hyperuricemia

Several studies suggest that chronic hyperuricemia, the main precursor of gout, is involved in the pathogenesis of different systemic disorders that affect cardiovascular and renal systems, such as hypertension, obesity, hypercholesterolemia, atherosclerosis, metabolic syndrome, chronic heart failure, and chronic kidney disease. Recent epidemiological evidence has shown an increasing trend in the prevalence of hyperuricemia and gout in the Western world: a number of population-based studies estimate a prevalence of up to 21% for hyperuricemia and 1%–4% for gout. As such, early detection and careful management of this pathological condition is required, starting from lifestyle changes (mainly based on a diet low in red meat, sugars, and alcoholic beverages, with increased intake of vegetables, water, and vitamin C sources), adding specific drugs to lead serum uric acid (SUA) levels under the target value of 7 mg/dL. In particular, nonselective and selective XO inhibitors (allopurinol, oxypurinol, febuxostat) reduce SUA levels and the overproduction of reactive oxygen species, mainly related to XO overactivity that often causes inflammatory damage to the vascular endothelium. The effect of lowering SUA levels via XO inhibition includes an attenuation of oxidative stress and related endothelial dysfunction that largely contribute to the pathophysiology of metabolic syndrome and cardiovascular diseases. Therefore, the inhibition of XO overactivation seems to be an excellent therapeutic option to limit the harmful effects of excess UA and reactive oxygen species. In conclusion, rapid diagnosis and correct therapy for hyperuricemia may also improve the prevention and/or treatment of serious and multifactorial diseases. The available evidence supports the importance of promoting new experimental clinical trials to confirm the emerging antioxidant role of XO inhibitors, which could effectively contribute to cardiovascular and chronic kidney disease prevention.

Microwave Heating of Synthetic Skin Samples for Potential Treatment of Gout Using the Metal-Assisted and Microwave-Accelerated Decrystallization Technique

Physical stability of synthetic skin samples during their exposure to microwave heating was investigated to demonstrate the use of the metal-assisted and microwave-accelerated decrystallization (MAMAD) technique for potential biomedical applications. In this regard, optical microscopy and temperature measurements were employed for the qualitative and quantitative assessment of damage to synthetic skin samples during 20 s intermittent microwave heating using a monomode microwave source (at 8 GHz, 2-20 W) up to 120 s. The extent of damage to synthetic skin samples, assessed by the change in the surface area of skin samples, was negligible for microwave power of ≤7 W and more extensive damage (>50%) to skin samples occurred when exposed to >7 W at initial temperature range of 20-39 °C. The initial temperature of synthetic skin samples significantly affected the extent of change in temperature of synthetic skin samples during their exposure to microwave heating. The proof of principle use of the MAMAD technique was demonstrated for the decrystallization of a model biological crystal (l-alanine) placed under synthetic skin samples in the presence of gold nanoparticles. Our results showed that the size (initial size ∼850 μm) of l-alanine crystals can be reduced up to 60% in 120 s without damage to synthetic skin samples using the MAMAD technique. Finite-difference time-domain-based simulations of the electric field distribution of an 8 GHz monomode microwave radiation showed that synthetic skin samples are predicted to absorb ∼92.2% of the microwave radiation.