Management of Gout

Research progress on bariatric surgery for hyperuricemia

Hyperuricemia is closely linked to obesity. As lifestyles and dietary patterns evolve, the prevalence of hyperuricemia has been on the rise. Bariatric surgery, an efficacious intervention for morbid obesity and its associated metabolic disorders, not only manages the weight of patients with severe obesity but also exerts beneficial therapeutic effects on hyperuricemia and gout. Moreover, it demonstrates substantial efficacy against other obesity-related metabolic conditions. However, the dramatic fluctuations in serum uric acid levels and acute gouty attacks in the immediate postoperative period are issues that should not be overlooked, and effective preventative strategies for some related adverse complications are still underexplored. This review discusses and reviews the advancements in the treatment of obese patients with hyperuricemia through bariatric surgery. By reviewing pertinent literature, it summarizes the short-term and long-term therapeutic outcomes of bariatric surgery for hyperuricemia, as well as common adverse reactions. Furthermore, by discussing preoperative and postoperative interventional measures and influential factors, this review aims to provide novel perspectives for the clinical management of hyperuricemia and offer insights for the prevention of related complications.

Clinical implications of persistent joint pain after gout flare

OBJECTIVES

A subset of gout patients developed persistent joint pain after flares. Analysis of this clinical phenomenon may shed further light on the factors related to worsening gout and even provide clues to its pathogenesis.

METHODS

We analyzed the clinical, laboratory, and ultrasound data of gout patients to explore the associations of these data with persistent joint pain after gout flares.

RESULTS

A total of 1029 gout patients were included: 182 (17.7%) patients with persistent joint pain and 847 (82.3%) patients with nonpersistent joint pain. Patients with persistent joint pain had more total involved joints, more gout flares in the past year, and more joints with simultaneous gout flares (P<0.01). Among the ultrasound-detected lesions, patients with persistent joint pain had a higher incidence of tophus (36.4% vs. 21.1%) and bone erosion (18.6% vs. 8.6%) (P<0.05). Higher UA and lower TBil were found in patients with persistent joint pain (P<0.001). Hypertension (54.9% vs. 38.7%) and metabolic syndrome (58.8% vs. 46.4%) were both more frequent in patients with persistent joint pain (P<0.05). TBil was negatively correlated with the incidence of persistent joint pain (P<0.001, r=-0.190), UA values (P<0.001, r=-0.125), and metabolic syndrome scores (P<0.001, r=-0.192). A correlation curve was fitted using LOESS (locally weighted region).

CONCLUSION

Persistent joint pain after gout flares is a marker of increased disease burden in gout. The significance of the level of total bilirubin for the exacerbation of gout deserves further study.

Interpretable machine learning framework to predict gout associated with dietary fiber and triglyceride-glucose index

BACKGROUND

Gout prediction is essential for the development of individualized prevention and treatment plans. Our objective was to develop an efficient and interpretable machine learning (ML) model using the SHapley Additive exPlanation (SHAP) to link dietary fiber and triglyceride-glucose (TyG) index to predict gout.

METHODS

Using datasets from the National Health and Nutrition Examination Survey (NHANES) (2005-2018) population to study dietary fiber, the TyG index was used to predict gout. After evaluating the performance of six ML models and selecting the Light Gradient Boosting Machine (LGBM) as the optimal algorithm, we interpret the LGBM model for predicting gout using SHAP and reveal the decision-making process of the model.

RESULTS

An initial survey of 70,190 participants was conducted, and after a gradual exclusion process, 12,645 cases were finally included in the study. Selection of the best performing LGBM model for prediction of gout associated with dietary fiber and TyG index (Area under the ROC curve (AUC): 0.823, 95% confidence interval (CI): 0.798-0.848, Accuracy: 95.3%, Brier score: 0.077). The feature importance of SHAP values indicated that age was the most important feature affecting the model output, followed by uric acid (UA). The SHAP values showed that lower dietary fiber values had a more pronounced effect on the positive prediction of the model, while higher values of the TyG index had a more pronounced effect on the positive prediction of the model.

CONCLUSION

The interpretable LGBM model associated with dietary fiber and TyG index showed high accuracy, efficiency, and robustness in predicting gout. Increasing dietary fiber intake and lowering the TyG index are beneficial in reducing the potential risk of gout.

Gout therapeutics and drug delivery

Gout is a common inflammatory arthritis caused by persistently elevated uric acid levels. With the improvement of people's living standards, the consumption of processed food and the widespread use of drugs that induce elevated uric acid, gout rates are increasing, seriously affecting the human quality of life, and becoming a burden to health systems worldwide. Since the pathological mechanism of gout has been elucidated, there are relatively effective drug treatments in clinical practice. However, due to (bio)pharmaceutical shortcomings of these drugs, such as poor chemical stability and limited ability to target the pathophysiological pathways, traditional drug treatment strategies show low efficacy and safety. In this scenario, drug delivery systems (DDS) design that overcome these drawbacks is urgently called for. In this review, we initially describe the pathological features, the therapeutic targets, and the drugs currently in clinical use and under investigation to treat gout. We also comprehensively summarize recent research efforts utilizing lipid, polymeric and inorganic carriers to develop advanced DDS for improved gout management and therapy.

Neutrophil autophagy induced by monosodium urate crystals facilitates neutrophil extracellular traps formation and inflammation remission in gouty arthritis

Neutrophil extracellular traps (NETs) are composed of chromatin filaments coated with granular and cytosolic proteins, which contribute to the pathogenesis and progression of immune-related diseases. NETs are frequently observed in gouty arthritis, but the related mechanisms remain poorly understood. The aim of our study was to systematically elucidate the molecular mechanisms of self-remitting effects in gouty arthritis, and the causative relationship between neutrophil autophagy and NETs. The air pouch and paw edema model were used to simulate gouty arthritis in mice. Neutrophil infiltration and the formation of NETs were found in gouty arthritis. Interestingly, monosodium urate (MSU) crystals could induce the formation of NETs, degrade inflammatory factors, and alleviate the inflammatory response in gouty arthritis. In addition, MSU crystals resulted in profound molecular alterations in neutrophils using RNA-seq analysis, including autophagy activation. MSU crystals could activate neutrophil autophagy in vitro, and autophagy activators and inhibitors could regulate the formation of NETs. Furthermore, we explored the mechanism of autophagy-induced NETs. Autophagy related protein 7 (ATG7) produced by neutrophils stimulated with MSU crystals worked synergistically with p53 to enter the nucleus, promoting peptidyl arginine deiminase 4 (PAD4) expression, and inducing the formation of NETs. Finally, we substantiated that neutrophil autophagy regulates the severity of gouty arthritis via the formation of NETs in PAD4 -/- mice. Our results indicated that the autophagy of neutrophils regulates the formation of NETs and degrades inflammatory factors. Regulating autophagy and interfering with the formation of NETs represents a potential therapeutic approach against gouty arthritis during clinical practice.

Rational design of a genome-based insulated system in Escherichia coli facilitates heterologous uricase expression for hyperuricemia treatment

Hyperuricemia is a prevalent disease worldwide that is characterized by elevated urate levels in the blood owing to purine metabolic disorders, which can result in gout and comorbidities. To facilitate the treatment of hyperuricemia through the uricolysis, we engineered a probiotic Escherichia coli Nissle 1917 (EcN) named EcN C6 by inserting an FtsP-uricase cassette into an "insulated site" located between the uspG and ahpF genes. Expression of FtsP-uricase in this insulated region did not influence the probiotic properties or global gene transcription of EcN but strongly increased the enzymatic activity for urate degeneration, suggesting that the genome-based insulated system is an ideal strategy for EcN modification. Oral administration of EcN C6 successfully alleviated hyperuricemia, related symptoms and gut microbiota in a purine-rich food-induced hyperuricemia rat model and a uox-knockout mouse model. Together, our study provides an insulated site for heterologous gene expression in EcN strain and a recombinant EcN C6 strain as a safe and effective therapeutic candidate for hyperuricemia treatment.

The effects of aerobic exercise on body composition in overweight and obese patients with gout: a randomized, open-labeled, controlled trial

BACKGROUND

Overweight and obesity are typical risk factors for the increased prevalence and incidence of gout. The existing guidelines unequivocally indicated that exercise is highly advantageous for patients with gout. Nevertheless, there is still a lack of specific guidance and clinical evidence. The effects of exercise on improving gout, and the optimal frequency, timing, and types of exercise have not been fully clarified. The present trial aims to determine the effects of a specific aerobic exercise program on body composition in overweight and obese patients with gout.

METHODS

In this randomized, open-labeled, controlled trial, a total of 60 overweight and obese patients with gout [body mass index (BMI) ≥ 24 kg/m2; age,18-55 years old] are equally randomized (1:1) into two groups (n = 30): moderate-intensity aerobic exercise group (MIAEG), heart rate reserve (HRR) = [(HRmax-HRrest) × 60% intensity] + HRrest, and control group (CG). The moderate-intensity aerobic exercise training program will be conducted for 30-40 min/session and 3 days/week for 12 weeks. Participants in the CG will be asked to avoid making changes in their exercise habits. There will be no limitation in the type of exercise. The primary outcome is the number of patients whose body fat is reduced after 12 weeks. The secondary outcomes include the changes in BMI, waist-to-hip ratio (WHR), insulin resistance index (IRI), serum uric acid (sUA), serum creatinine (SCr), estimated glomerular filtration rate (eGFR), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hepatic steatosis, and adverse effects after 12 weeks. One-way analysis of variance (ANOVA) will be used to compare the mean values of normally distributed variables between MIAEG and GC.

DISCUSSION

The effect and optimal frequency of exercise for improving the status of overweight and obese patients with gout have not yet been determined. We design a 12-week randomized controlled trial and evaluate the effects of individualized aerobic exercise program on patients with gout. The results may assist such patients with a personalized scientific exercise program based on the disease status and motor abilities, so that patients are prone to exercise under the condition of low risk and achieve the greatest benefits.

TRIAL REGISTRATION

ChiCTR2200062153. Registered on July 25, 2022, with ChiCTR. http://www.chictr.org.cn/.

Is Renoprotection Real for Patients with Hyperuricemia?

Number of patients with progressive chronic kidney disease (CKD) is increasing all over the world. One of the risk factors for CKD development and progression is increased serum uric acid (sUA) level. Possibly, control of hyperurcemia with urate lowering therapy drugs can slow the decline in kidney function. The objective: to determine efficacy and safety of allopurinol and febuxostat in treatment of patients with CKD and hyperurcemia to reduce the sUA level and analyze its influence on glomerular filtration rate (GFR). Materials and methods. The study included 45 CKD patients (stages 3b-5) without other severe/decompensated diseases and contraindications to the allopurinol/febuxostat. All patients underwent a comprehensive clinical and laboratory examination, and were divided into the study groups: Group I (28 patients, 61.3±3.2 y.o., CKD3b-12, CKD4-10, on hemodialysis-6 patients) received febuxostat, Group II (24 patients, 60.7Ѓ}4.1 y.o., CKD3b-9, CKD4-10, on hemodialysis – 5 patients) took allopurinol. Results. Achievement of the target level of sUA was significantly often registered in Group I: after 1 month – in 45.5% (in group II – in 15.9%, p<0.001); after 3 months – in 67.5% (in group II – 21.2% p<0.01); after 6 months, these figures were 90% and 37.1%, respectively (p<0.01). sUA level <300 μmol/l was accompanied by significant positive GFR changes in group I patients; in group II there was a gradual progression of GFR deterioration in 31.8% of patients. Conclusions. In patients with pre-dialysis stages of CKD febuxostat demonstrates renoprotective abilities. Use of febuxostat in patients with CKD stage 3b-4 and in patients on hemodialysis is safe and more effective for target sUA level achievement than the use of allopurinol.