Gout Is Prevalent but Under-Registered Among Patients With Cardiovascular Events: A Field Study

A Review of Medicinal Plants and Phytochemicals for the Management of Gout

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

Filling gaps in female gout: a cross-sectional study of comorbidities in 192 037 hospitalised patients

OBJECTIVE

There is room for improvement in the knowledge of female gout, often noted at risk of gender blindness. This study aims to compare the prevalence of comorbidities in women versus men hospitalised with gout in Spain.

METHODS

This is an observational, multicentre, cross-sectional study in public and private Spanish hospitals analysing the minimum basic data set from 192 037 hospitalisations in people with gout (International Classification of Diseases, Ninth Revision (ICD-9) coding) from 2005 to 2015. Age and several comorbidities (ICD-9) were compared by sex, with a subsequent stratification of comorbidities by age group. The association between each comorbidity and sex was assessed using multivariable logistic regression. A clinical decision tree algorithm was constructed to predict the sex of patients with gout based on age and comorbidities alone.

RESULTS

Women with gout (17.4% of the sample) were significantly older than men (73.9±13.7 years vs 64.0±14.4 years, p<0.001). Obesity, dyslipidaemia, chronic kidney disease, diabetes mellitus, heart failure, dementia, urinary tract infection and concurrent rheumatic disease were more common in women. Female sex was strongly associated with increasing age, heart failure, obesity, urinary tract infection and diabetes mellitus, while male sex was associated with obstructive respiratory diseases, coronary disease and peripheral vascular disease. The decision tree algorithm built showed an accuracy of 74.4%.

CONCLUSIONS

A nationwide analysis of inpatients with gout in 2005-2015 confirms a different comorbidity profile between men and women. A different approach to female gout is needed to reduce gender blindness.

A glance into the future of gout

Gout is characterized by monosodium urate (MSU) crystal deposits in and within joints. These deposits result from persistent hyperuricaemia and most typically lead to recurrent acute inflammatory episodes (gout flares). Even though some aspects of gout are well characterized, uncertainties remain; this upcoming decade should provide further insights into many of these uncertainties. Synovial fluid analysis allows for the identification of MSU crystals and unequivocal diagnosis. Non-invasive methods for diagnosis are being explored, such as Raman spectroscopy and imaging modalities. Both ultrasound and dual-energy computed tomography (DECT) allow the detection of MSU crystals; this not only provides a mean of diagnosis, but also has furthered gout knowledge defining the presence of a preclinical deposition in asymptomatic hyperuricaemia. Scientific consensus establishes the beginning of gout as the beginning of symptoms (usually the first flare), but the concept is currently under review. For effective long-term gout management, the main goal is to promote crystal dissolution treatment by reducing serum urate below 6 mg/dL (or 5 mg/dL if faster crystal dissolution is required). Current urate-lowering therapies' (ULTs) options are limited, with allopurinol and febuxostat being widely available, and probenecid, benzbromarone, and pegloticase available in some regions. New xanthine oxidase inhibitors and, especially, uricosurics inhibiting urate transporter URAT1 are under development; it is probable that the new decade will see a welcomed increase in the gout therapeutic armamentarium. Cardiovascular and renal comorbidities are common in gout patients. Studies determining whether optimal treatment of gout will positively impact these comorbidities are currently lacking, but will hopefully be forthcoming. Overall, the single change that will most impact gout management is greater uptake of international rheumatology society recommendations. Innovative strategies, such as nurse-led interventions based on these recommendations have recently demonstrated treatment success for people with gout.

Birefringent Crystals Deposition and Inflammasome Expression in Human Atheroma Plaques by Levels of Uricemia

OBJECTIVE

To verify the monosodium urate (MSU) crystal deposition in artery walls following a structure assessment and to assess NLRP3 inflammasome expression in human atheroma plaques by levels of uricemia.

METHODS

Patients with peripheral arterial disease who were candidates for amputation were recruited and classified as normouricemic or hyperuricemic. During surgery, an artery segment from the amputated limb was sampled, divided and fixed separately by cryo-embedding, 100% ethanol or Glyo-fixx. Samples were assessed by compensated polarized-light microscopy to identify MSU crystals on the artery walls. Afterwards, macrophages, neutrophils and NLRP3 inflammasome components at the plaque were categorized by immunostaining and compared between normouricemics and hyperuricemics.

RESULTS

Thirty artery samples from 27 patients were studied; 10 (37.0%) participants were hyperuricemic. Birefringent needle-shaped crystals were found in three samples (10.0%), all processed by frozen sectioning. Other methods showed no crystals. No accompanying inflammatory process was noted, and the presence of crystals was equally distributed across ranges of uricemia, making it unlikely they were MSU crystals. Regarding immunostaining, 28 artery samples were available for analysis, with similar infiltration of macrophages and neutrophils. NLRP3 and gasdermin-D expression were significantly greater in hyperuricemics compared to normouricemics (p=0.044 and p=0.017, respectively). ASC content was numerically larger in hyperuricemics as well, while caspase-1 and IL-1beta expression were similar between groups.

CONCLUSIONS

The presence of MSU crystals on artery walls was not confirmed. Hyperuricemia was associated with greater NLRP3 and gasdermin-D expression on human atheroma plaques in patients with peripheral artery disease.

Xanthine oxidoreductase: A leading actor in cardiovascular disease drama

Cardiovascular diseases (CVD) are the leading cause of global mortality and their pathogenesis lies mainly in the atherosclerotic process. There are close connections linking oxidative stress and inflammation to endothelial dysfunction, atherosclerosis and, consequently, to CVD. This review focuses on the role of xanthine oxidoreductase (XOR) and its products on the development of chronic inflammation and oxidative stress, responsible for atheromatous plaque formation. Evidence is reported that an excessive level of XOR products favors inflammatory response and plaque development, thereby promoting major cardiovascular risk factors. Also, the relationship between hyperuricemia and hypertension as well as between XOR activity and CVD is confirmed. In spite of the increasing number of clinical studies investigating the output of cardiovascular patients treated with urate-lowering therapies (including uricosuric drugs, XOR inhibitors and recombinant uricase) the results are still uncertain. The inhibition of XOR activity appears more promising than just the control of uricemia level in preventing cardiovascular events, possibly because it also reduces the intracellular accumulation of urate, as well as the production of reactive oxygen species. However, XOR inhibition also reduces the availability of the multifaced mediator nitric oxide and, at present, can be recommended only in hyperuricemic patients.

Risk of osteoporotic thoracic vertebral fractures in patients with gout

OBJECTIVES

Osteoporosis causes significant morbidity and mortality by the development of fragility fractures, including vertebral fractures. Patients with gout may show an increased risk of osteoporotic fractures, as accelerated bone resorption is likely linked to urate crystal-led inflammatory state. This study aims to evaluate the risk of osteoporotic dorsal vertebral fractures associated with gout.

METHODS

Cross-sectional study carried out in patients admitted for cardiovascular events. Patients with available lateral view of chest radiography (on admission or in the previous six months) were selected. Two observers blinded to clinical data reviewed the radiographies simultaneously. Vertebral fracture was defined as a vertebral height loss ≥20%, and presence, number, and severity (by Genant semi-quantitative scale) were registered. To analyse the relationship between gout and the presence of vertebral fractures, the odds ratio (OR) with 95% confidence interval (95%CI) was calculated by multiple logistic regression.

RESULTS

126 patients were analysed, 21 of them (16.67%) suffered from gout. Eighteen cases with fractures were detected, with a prevalence of 14.3%. A significant association was found between gout and vertebral fracture (28.6% gout, 11.4% controls; OR 3.10, 95%CI 1.01-9.52). There were no differences in the number of fractures, while the severity was found to be higher in the controls. The association between gout and vertebral fracture persisted after multivariate adjustment (OR 5.21, 95% CI 1.32-20.61).

CONCLUSION

An independent association between gout and radiological thoracic vertebral fractures was revealed in patients with a cardiovascular event.

Risk of osteoporotic thoracic vertebral fractures in patients with gout

OBJECTIVES

Osteoporosis causes significant morbidity and mortality by the development of fragility fractures, including vertebral fractures. Patients with gout may show an increased risk of osteoporotic fractures, as accelerated bone resorption is likely linked to urate crystal-led inflammatory state. This study aims to evaluate the risk of osteoporotic dorsal vertebral fractures associated with gout.

METHODS

Cross-sectional study carried out in patients admitted for cardiovascular events. Patients with available lateral view of chest radiography (on admission or in the previous six months) were selected. Two observers blinded to clinical data reviewed the radiographies simultaneously. Vertebral fracture was defined as a vertebral height loss ≥20%, and presence, number, and severity (by Genant semi-quantitative scale) were registered. To analyse the relationship between gout and the presence of vertebral fractures, the odds ratio (OR) with 95% confidence interval (95%CI) was calculated by multiple logistic regression.

RESULTS

126 patients were analysed, 21 of them (16.67%) suffered from gout. Eighteen cases with fractures were detected, with a prevalence of 14.3%. A significant association was found between gout and vertebral fracture (28.6% gout, 11.4% controls; OR 3.10, 95%CI 1.01-9.52). There were no differences in the number of fractures, while the severity was found to be higher in the controls. The association between gout and vertebral fracture persisted after multivariate adjustment (OR 5.21, 95% CI 1.32-20.61).

CONCLUSION

An independent association between gout and radiological thoracic vertebral fractures was revealed in patients with a cardiovascular event.