Prevalence of gout with comorbidity aggregations in southern Taiwan

Epidemiology and treatment-related concerns of gout and hyperuricemia in Korean

Gout is the most common form of inflammatory arthritis that affects mainly middle-aged men, and there is clear evidence of an association between hyperuricemia and the risk for gout. Increasing prevalence of gout and hyperuricemia has been reported in many countries. The prevalence of gout and hyperuricemia are constantly increasing in Korea with the patients at risk for developing a variety of comorbidities. Although there have been studies on the association between gout or serum uric acid level and several neurodegenerative diseases, cancer, and cardiovascular mortality, the causal relationship between gout and these comorbidities are still unclear. The associations of substantial economic burden with hyperuricemia, gout attack, and suboptimal treatment are well known. Gout is a disease that requires lifelong management including lifestyle modification. However, gout is poorly managed worldwide although effective urate-lowering drugs exist. In this review, we addressed epidemiological studies and treatment-related problems in the Korean population with gout or hyperuricemia to obtain the best clinical outcomes and reduce their medical burden.

Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout

Objective

To develop a Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout, with the goal of increasing public understanding and awareness, and ensure consistent and understandable messages about gout.

Methods

A G-CAN working group that included patients, physicians and nongovernmental organisation (NGO) representatives was formed to develop a common language definition of gout for use with the public, media, healthcare providers and stakeholders. A literature search and interviews with patients, healthcare workers and stakeholders informed development of the definition. Following consultation with G-CAN members and partners, the definition was endorsed by the G-CAN board.

Results

The G-CAN common language definition of gout describes the epidemiology, pathophysiology, symptoms and impact, risk factors, comorbidities, management and healthcare and workforce considerations. Detailed information is provided to support the content of the definition. After the publication of the English-language version, the definition will be available for translation into other languages by G-CAN members.

Conclusion

G-CAN has developed a concise and easily understandable statement describing gout in language that can be used in conversations with the lay public, media, NGOs, funders, healthcare providers and other stakeholders.

Effect modification of hyperlipidemia and hypertension on the association between type 2 diabetes and gout

AIMS

We evaluated the association between type 2 diabetes and gout by a retrospective cohort study.

METHODS

Data of 17,259 male and 18,318 female patients with type 2 diabetes were retrieved for the 1998-2010 period. These patients were matched to a comparison group (n=34,518 and n=36,636, respectively) in a 1:2 ratio by age and region.

RESULTS

We found that patients with type 2 diabetes after adjustment for hyperlipidemia and hypertension had a lower risk of incident gout than the matched population (incidence rate ratio, men: 0.39 [95% CI: 0.36-0.42]; women: 0.78 [0.72-0.84]). Specifically, type 2 diabetes alone without hyperlipidemia and hypertension was associated with a reduced risk of incident gout in men (adjusted relative risk [RR]: 0.29, 95% CI: 0.22-0.39), but not in women (0.86, 95% CI: 0.55-1.36). We found that insulin users with hyperlipidemia and hypertension associated with risk of incident gout and no sex-specific differences were noted (adjusted RR, men: 1.28 [95% CI: 1.11-1.48]; women: 1.32 [95% CI: 1.14-1.53]). Specifically, insulin users alone without hyperlipidemia and hypertension were not statistically significantly associated with gout risk (P≥.0954).

CONCLUSIONS

The results of this study indicated that hyperlipidemia and hypertension modified the association between type 2 diabetes and gout.

Global epidemiology of gout: prevalence, incidence, treatment patterns and risk factors

Gout is the most common inflammatory arthritis and occurs when hyperuricaemia, sustained elevation of serum urate levels resulting in supersaturation of body tissues with urate, leads to the formation and deposition of monosodium urate crystals in and around the joints. Recent reports of the prevalence and incidence of gout vary widely according to the population studied and methods employed but range from a prevalence of <1% to 6.8% and an incidence of 0.58-2.89 per 1,000 person-years. Gout is more prevalent in men than in women, with increasing age, and in some ethnic groups. Despite rising prevalence and incidence, suboptimal management of gout continues in many countries. Typically, only a third to half of patients with gout receive urate-lowering therapy, which is a definitive, curative treatment, and fewer than a half of patients adhere to treatment. Many gout risk factors exist, including obesity, dietary factors and comorbid conditions. As well as a firmly established increased risk of cardiovascular disease and chronic kidney disease in those with gout, novel associations of gout with other comorbidities have been reported, including erectile dysfunction, atrial fibrillation, obstructive sleep apnoea, osteoporosis and venous thromboembolism. Discrete patterns of comorbidity clustering in individuals with gout have been described. Increasing prevalence and incidence of obesity and comorbidities are likely to contribute substantially to the rising burden of gout.

Anti-hyperuricemic and Anti-inflammatory Effects of Marantodes pumilum as Potential Treatment for Gout

Marantodes pumilum (Primulaceae) has been used in Malaysian folk medicine to help women regain strength after delivery and for “sickness in the bones.” It was previously revealed that its extracts inhibited xanthine oxidase (XO) activity in vitro. The leaves and roots of M. pumilum var. alata (MPA), var. pumila (MPP), and var. lanceolata (MPL) were individually extracted in ethanol (80%). The anti-hyperuricemic activity was initially assessed by XO inhibition with a spectrophotometric in vitro assay. The most active extract was further investigated on hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels and liver XO effect. The in vitro anti-inflammatory activity was carried out on monosodium urate (MSU) crystal-induced pro-inflammatory cytokines (i.e., interleukin (IL)1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α) secretion using human peripheral blood mononuclear cells and ELISA technique, and prostaglandin E₂ (PGE₂)secretion using radioimmunoassay. The active extract was then investigated on gout-induced inflammation with MSU crystals to determine pro-inflammatory cytokines and PGE₂ secretion levels in the synovial fluid of rat knee joint. Quantitative analysis using validated HPLC was performed on the extracts to determine presence of bioactive flavonoids. The findings revealed that extract of MPP leaves gave the highest inhibitory activity on XO (IC₅₀ 130.5 μg/mL) compared to other extracts tested. However, all extracts possessed significantly lower activity compared to allopurinol (IC₅₀ 0.13 μg/mL). Oral administration of MPP leaf extract (200 mg/kg) significantly reduced serum uric acid level in hyperuricemic rats in time-dependent manner to the baseline level and it was as effective as allopurinol (5 mg/kg). The extract also inhibited liver XO activity (25%) compared to allopurinol (45%). In vitro anti-inflammatory assay showed that extract of MPP roots inhibited MSU crystals-induced secretion of IL-1α, IL-1β, IL-8, TNF-α, and PGE₂ with IC₅₀ values of 36, 25, 38, 18, and 46 μg/mL, respectively. Oral administration of the MPP root extract (200 mg/kg) significantly decreased IL-1α, IL-1β, IL-6, TNF-α, and PGE₂ levels in rat’s synovial fluid as effective as indomethacin. There were no significant body weight changes of all experimental animals. MPP extracts showed presence of myricetin, quercetin and kaempferol. Myricetin was detected with values of 0.2 and 0.6 mg/g for root and leaf extracts, respectively. The anti-hyperuricemic of MPP leaf and anti-inflammatory of MPP root indicated that MPP may be promising for complementary therapy of gout.

Differential risk group of developing stroke among older women with gouty arthritis: A latent transition analysis

OBJECTIVE

Gout-related comorbidities are intricate and its clinical features may demonstrate sex difference; however, few studies have evaluated the links between comorbidities and gout in a female population. The objectives of this study were to compare the aggregation and transitive trajectories of comorbidities of gout, and their consequences in female and male gout populations.

METHODS

A prospective cohort study was conducted using data from the Taiwan National Health Insurance Research Database. A female and male gout population were followed up from 2000 to 2009 to identify the comorbidities of cardiovascular disease, hyperlipidemia, hypertension, diabetes mellitus (DM) and chronic kidney disease. The cumulative incidence of stroke from 2000 to 2010 was examined. A latent trajectory analysis was used to determine the transitive trajectories of the comorbidities of gout.

RESULTS

Both female and male patients with gout had five risk cluster transition (CT) phenotypes of comorbidities within 10-year follow-up: CT1 and CT2, with various persistent comorbidities; CT3, with few persistent comorbidities; and CT4 and CT5, with transfer to cluster 1 from other clusters. The female participants in CT2 predominantly experienced DM and were associated with significantly increased risk of developing stroke.

CONCLUSION

Diabetes is a notable risk factor for the development of stroke in female patients with gout. Early assessment and management for the comorbidities of gout, particularly in DM, would effectively reduce future stroke risk in female gout population.

Prevalence and incidence of gout in Korea: data from the national health claims database 2007-2015

The purpose of the present study was to investigate the prevalence and incidence of gout in Korea and predict the future prevalence and incidence of gout. Data were collected from the national health claims database. Patients who had at least one claim for gout between 2007 and 2015 were included in the study. The prevalence of gout from 2007 to 2015 and the incidence of gout from 2009 to 2015 were determined. We estimated sex- and age-specific prevalence and incidence of gout during the period. The prevalence and incidence of gout were predicted using time series analysis. The prevalence of gout (95% CI) increased from 3.49 (3.48-3.51) per 1000 persons in 2007 to 7.58 (7.55-7.60) per 1000 persons in 2015. The incidence of gout (95% CI) was 1.52 (1.51-1.53) in 2009 and rose to 1.94 (1.93-1.95) per 1000 persons in 2015. The prevalence and incidence of gout were higher in men than in women. The older population had a higher prevalence and incidence than the younger population. The increase in prevalence was higher in the older population than the younger population, whereas the increase in incidence was higher in the younger population than the older population. The predicted prevalence and incidence of gout (95% CI) in 2025 were 16.59 (15.85-17.34) per 1000 persons and 3.81 (3.14-4.47) per 1000 persons. The prevalence and incidence of gout increased in Korea between 2007 and 2015. Men and the older population had a higher prevalence and incidence of gout compared to women and the younger population. However, the incidence of gout in the younger population has increased rapidly in recent years.

Association Between Gout and Incident Type 2 Diabetes Mellitus: A Retrospective Cohort Study

OBJECTIVE

We investigated the association between gout and the risk of type 2 diabetes mellitus.

METHODS

Population-based representative insurance (outpatient and inpatient) claims data of 29,765 patients with gout and 59,530 controls without gout (1:2 case:control ratio) between 1998 and 2010 in Taiwan were identified. The association between gout and type 2 diabetes was evaluated using the Cox proportional hazards model. Moreover, the combined effects of sex and incident gout on the risk of type 2 diabetes were estimated.

RESULTS

In total, 3940 patients (13.24%) with gout and 6334 controls (10.64%) developed type 2 diabetes in the follow-up period. Multivariate analyses revealed a significant association between gout and type 2 diabetes. Compared with the control group, the adjusted hazard ratios (95% confidence intervals) for type 2 diabetes were 1.62 (1.54-1.70) in men, 1.97 (1.81-2.14) in women, and 1.70 (1.62-1.77) overall. The multiplicative interaction was β = 0.18 and P = .0001, suggesting a positive interaction between sex and incident gout. Moreover, compared with men without gout, a significantly higher risk of type 2 diabetes was noted in women without gout (adjusted relative risk [95% confidence interval], 1.17 [1.10-1.24]), men with gout (1.11 [1.06-1.16]), and women with gout (1.47 [1.37-1.57]) (P for interaction = .0058).

CONCLUSIONS

Gout is a strong and independent risk factor for type 2 diabetes, and female patients with gout are at a higher risk of type 2 diabetes than are male patients with gout.

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.

Alcohol-related diseases and alcohol dependence syndrome is associated with increased gout risk: A nationwide population-based cohort study

OBJECTIVE

Alcohol intake is strongly associated with hyperuricemia, which may cause gout. This study evaluated the risk of gout in patients with alcohol-related diseases and alcohol dependence syndrome.

METHODS

We used the Taiwan National Health Insurance Research Database (NHIRD) to conduct a nationwide population-based cohort study to assess the risk of gout and gout incidence in patients with alcohol-related diseases and alcohol dependence syndrome (as defined by the International Classification of Diseases, Ninth Revision). In the NHIRD records from 1998 to 2008, we identified 11,675 cases of alcohol-related diseases. The control group comprised 23,350 cases without alcohol-related diseases propensity score-matched (1 case: 2 controls) for age, age group, and sex.

RESULTS

The results revealed that alcohol-related diseases were significantly associated with gout risk (adjusted hazard ratio 1.88; P<0.0001). Of the alcohol-related disease cases, 34.1% of the patients had alcohol dependence syndrome (males 34.8%; females 32.4%), and alcohol dependence was independently associated with gout occurrence (relative risk [RR] 2.01; P<0.0001). Severe alcohol-dependent patients (who were also the heavy benzodiazepines users), were associated with an increased risk of gout (RR 1.71 to 4.21, P≤0.0182).

CONCLUSION

Physicians should be aware of the association between alcohol dependence syndrome and gout occurrence, and alcohol use assessment and measures to prevent alcohol dependence should be implemented in the integrative care for patients with gout.

Global epidemiology of gout: prevalence, incidence and risk factors

Gout is a crystal-deposition disease that results from chronic elevation of uric acid levels above the saturation point for monosodium urate (MSU) crystal formation. Initial presentation is mainly severely painful episodes of peripheral joint synovitis (acute self-limiting 'attacks') but joint damage and deformity, chronic usage-related pain and subcutaneous tophus deposition can eventually develop. The global burden of gout is substantial and seems to be increasing in many parts of the world over the past 50 years. However, methodological differences impair the comparison of gout epidemiology between countries. In this comprehensive Review, data from epidemiological studies from diverse regions of the world are synthesized to depict the geographic variation in gout prevalence and incidence. Key advances in the understanding of factors associated with increased risk of gout are also summarized. The collected data indicate that the distribution of gout is uneven across the globe, with prevalence being highest in Pacific countries. Developed countries tend to have a higher burden of gout than developing countries, and seem to have increasing prevalence and incidence of the disease. Some ethnic groups are particularly susceptible to gout, supporting the importance of genetic predisposition. Socioeconomic and dietary factors, as well as comorbidities and medications that can influence uric acid levels and/or facilitate MSU crystal formation, are also important in determining the risk of developing clinically evident gout.

Hospital burden of gout, pseudogout and other crystal arthropathies in France

OBJECTIVE

To describe the hospital burden of microcrystal arthropathies in France.

METHODS

Data were extracted from the 2009-2011 French hospital national databases. We selected all hospital stays for microcrystal arthropathies (gout, chondrocalcinosis, other) encoded as primary or secondary diagnoses in patients older than 18. A descriptive analysis focused on number of patients and hospital stays, age, gender, comorbidities related to metabolic syndrome, and hospital costs based on 2012 public-sector costs.

RESULTS

132,275 hospitalizations involving 109,734 patients were related to microcrystal arthropathies encoded as primary or secondary diagnosis (61% related to gout, 34% to chondrocalcinosis, and 5% to other microcrystal arthropathies). 23,362 hospitalizations involving 25,105 patients were due to microcrystal diseases, encoded as primary diagnosis, (48% related to gout, 43% to chondrocalcinosis, and 9% to other microcrystal arthropathies). In this population, patients with chondrocalcinosis were older (mean 75.6±13.5 versus 71±16 years for other microcrystal arthropathies and 69.7±14.7 for gout). Men represented 70% of the patients with gout, 39% of those with chondrocalcinosis and 52% of the patients with other microcrystal arthropathies. Hypertension, diabetes, dyslipidemia, cardiac ischemia, and renal failure were more frequent in patients with gout than other patients. The hospital costs for microcrystal arthropathies encoded as primary diagnosis were 82.3 million Euros, 45% related to gout, 45% to chondrocalcinosis and 11% to other microcrystals.

CONCLUSION

In terms of hospital costs, gout and chondrocalcinosis represented the main part of the economic burden of crystal arthropathies and a high level of diseases belonging to the metabolic syndrome. Specific education programs favouring accurate microcrystal diagnosis and adherence to treatment could diminish this hospital economic burden.