A literature review of the epidemiology and treatment of acute gout

[Gout in the spine: a rare presentation of a common disorder]

A 92-year old woman was admitted to the geriatric department because of a confusional state due to a urinary tract infection, a severe dermatitis and gout. An incomplete tetraplegia was found on physical examination. Radiological examination showed a large gouty tophus causing spinal cord compression and destruction of the dens. Gouty involvement of the spine is a less common complication of the disease. Optimal treatment of gout is important to prevent the development of such severe complications.

Cost-effectiveness analysis of febuxostat in patients with gout in Spain

Objectives Cost-effectiveness of febuxostat compared with allopurinol in the treatment of hyperuricemia in patients with gout. Methods Costs, clinical outcomes, and QALYs were estimated using a Markov model. Febuxostat 80 mg and 120 mg sequentially, used as first line and second line therapy, was compared with allopurinol 300 mg. Patients switched to the next treatment in the sequence according to a dichotomous response vs no response (target serum urate level < 6 mg/dl outcome) after 3 months of active treatment. A 3% discount rate and 5-year time horizon were applied.

PERSPECTIVE

National Health System. Results The addition of febuxostat to any therapeutic strategy was an efficient option, with incremental cost-effectiveness ratios (ICER) compared with allopurinol 300 mg ranging from €5268-€9737. Conclusions Febuxostat is a cost-effective treatment in Spain for the management of hyperuricemia in gout patients, with ICERs far below accepted Spanish efficiency thresholds (30 000€/QALY).

Comparison of Prednisolone, Etoricoxib, and Indomethacin in Treatment of Acute Gouty Arthritis: An Open-Label, Randomized, Controlled Trial

Background

At present there are several kinds of medicine for treating acute gout arthritis (AGA). This study compared the efficacy and safety of prednisolone, etoricoxib, and indomethacin in the treatment of AGA.

Material/Methods

This was an open-label, randomized, active-comparator study in patients with AGA. Patients were randomized to 4 days of prednisolone 35 mg qd, etoricoxib 120 mg qd, or indomethacin 50 mg tid. The primary efficacy endpoint was the reduction of self-assessed pain in the index joint from baseline. Secondary endpoints included changes in physician’s assessment of tenderness, erythema, swelling, and joint activity; patient assessment of response to therapy; and safety.

Results

We analyzed 113 patients. Baseline demographics were comparable among treatment groups. Oral prednisolone, etoricoxib, and indomethacin were similarly effective in improving pain, tenderness, and joint activity over 4 days. For inflammation, oral prednisolone, etoricoxib, and indomethacin were similarly effective in reducing erythema, but prednisolone might be more effective in reducing swelling than indomethacin. The patient response to therapy was similar in the 3 groups. There were more total adverse events with indomethacin compared with the other 2 drugs.

Conclusions

Efficacy was comparable among prednisolone, etoricoxib, and indomethacin for the treatment of AGA. Prednisolone might be more effective in reducing inflammation and it had a better safety profile.

Dual-Energy CT in Patients with Suspected Gouty Arthritis: Effects on Treatment Regimen and Clinical Outcome

RATIONALE AND OBJECTIVES

This investigation aimed to evaluate the impact on treatment regimen and clinical outcome of dual-energy computed tomography (DECT) in patients with suspected gouty arthritis.

MATERIALS AND METHODS

We retrospectively analyzed electronic medical records (EMR) of 39 patients (36 male, 3 female; age range, 36-85 years) who underwent DECT of peripheral joints because of suspected gouty arthritis. We assessed the prior medical history, lab results, treatment regimen, and medications before and after DECT, and changes in subjective severity of symptoms as stated by patients in the EMR. The presence of monosodium urate (MSU) crystals in the index joint was verified with DECT.

RESULTS

Several patients had a prior diagnosis of gout (n = 9), hyperuricemia (n = 6), rheumatoid arthritis (n = 3), or psoriatic arthritis (n = 3). Elevated uric acid blood levels were detected in 32 patients (82%) before DECT. On DECT, MSU crystals were detected in 23 patients (59%). Of the 36 cases, the current treatment regimen was modified after DECT to gout-specific therapy in 22 cases and other rheumatic diseases were targeted in 14 cases. Several medications were prescribed more frequently based after DECT compared to before DECT imaging, including steroids (n = 20 vs. n = 12, respectively), colchicine (n = 13 vs. n = 4, respectively), and urate-lowering medication (n = 18 vs. n = 11, respectively). A subjective reduction of clinical symptoms during cumulative follow-up was reported by 34 patients (87.2%).

CONCLUSIONS

Both positive and negative findings of MSU crystals on DECT have a significant impact on the treatment regimen and clinical outcome of patients with suspected gouty arthritis and facilitate differentiation from other rheumatic diseases.

Barriers to Care in Gout: From Prescriber to Patient

OBJECTIVE

To explore the understanding of gout and its management by patients and general practitioners (GP), and to identify barriers to optimal gout care.

METHODS

Semistructured interviews were conducted with 15 GP and 22 patients in Sydney, Australia. Discussions were focused on medication adherence, experiences with gout, and education and perceptions around interventions for gout. Interviews were audio recorded, transcribed verbatim, and analyzed for themes using an analytical framework.

RESULTS

Adherence to urate-lowering medications was identified as problematic by GP, but less so by patients with gout. However, patients had little appreciation of the risk of acute attacks related to variable adherence. Patients felt stigmatized that their gout diagnosis was predominantly related to perceptions that alcohol and dietary excess were causal. Patients felt they did not have enough education about gout and how to manage it. A manifestation of this was that uric acid concentrations were infrequently measured. GP were concerned that they did not know enough about managing gout and most were not familiar with current guidelines for management. For example and importantly, the strategies for reducing the risk of acute attacks when commencing urate-lowering therapy (ULT) were not well appreciated by GP or patients.

CONCLUSION

Patients and GP wished to know more about gout and its management. Greater success in establishing and maintaining ULT will require further and better education to substantially benefit patients. Also, given the prevalence, and personal and societal significance of gout, innovative approaches to transforming the management of this eminently treatable disease are needed.

Overcoming adherence issues and other barriers to optimal care in gout

PURPOSE OF REVIEW

This review presents research published over the last year examining use of urate-lowering therapy (ULT) as well as trends over time in adherence to this class of agents. Additionally, it explores factors associated with nonadherence to ULTs for chronic gout and interventions to improve chronic gout management.

RECENT FINDINGS

New literature suggests prescriptions of ULTs for prevalent and incident gout patients remains lower than expected based on the burden of the disease in the population. Overall ULT adherence remains suboptimal, in part related to inadequate patient education and copayment costs; although one study demonstrated improvement in adherence over a 15-year study period. Finally, interventions that include patient education and medication titration based on laboratory results successfully lowered serum urate levels to less than 6 mg/dl in the majority of patients.

SUMMARY

Gout remains a prevalent disease that is poorly managed despite effective treatments. Recent research suggests that ULTs are underutilized and even when prescribed are not well adhered to. Patient-centered interventions that focus on education about pharmacologic therapy and lifestyle modifications with medication titration have resulted in a greater proportion of patients achieving recommended serum urate levels.

Study on the anti-gout activity of chlorogenic acid: improvement on hyperuricemia and gouty inflammation

Gout is a metabolic disorder associated with hyperuricemia resulting in the deposition of monosodium urate (MSU) crystals in joints and tissues. Lowering serum uric acid (Sur) levels and anti-inflammation are highly essential in treating gout. Chlorogenic acid (CA), as one of the most abundant polyphenols in the Chinese medicines, has been rarely reported to have an anti-gout effect. The model of potassium oxonate (PO)-induced hyperuricemia in mice and MSU crystal-induced inflammation in rats has been established in this study. The potential beneficial effects and mechanisms of CA on hyperuricemia and gouty arthritis were elucidated. The results demonstrated that CA significantly decreased the Sur level by inhibiting the xanthine oxidase (XOD) activity but not increasing the urinary uric acid (Uur) level. In addition, CA also exhibited the effect of suppressing paw swelling. Further investigation indicated that CA improved the symptoms of inflammation induced by MSU crystals by inhibiting the production of proinflammatory cytokines including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The present study suggests that CA may have a considerable potential for development as an anti-gouty arthritis agent for clinical application.

Development and Validation of LC-MS/MS Method for Quantitative Determination of Adenosine, Guanosine, Xanthine and Uric Acid in Widely Consumed Vegetables in Thailand

In this study, a triple quadrupole LC-MS/MS electrospray ionization method was developed and validated for quantitative determination of adenosine, guanosine, xanthine and uric acid in fifteen widely consumed Thai vegetables. The method was successively developed by using caffeine as internal standard. The lower limit of quantitation (LLOQ) was 0.2 μg/g for adenosine and guanosine, and 1.0 μg/g for uric acid and xanthine. The method was fully validated according to USFDA guidelines and all performance characteristics were found acceptable. Subsequently, the developed and validated LC-MS/MS method was applied to determine the four interest substances in fifteen widely consumed vegetables in Thailand. The results showed that all vegetables included in the study could be classified as low adenosine, guanosine, xanthine and uric acid containing foods since the concentrations of these substances were less than 50 mg per 100 g. This finding was enormously valuable information for hyperuricemia and gouty patients.

The complete chloroplast genome of colchicine plants (Colchicum autumnale L. and Gloriosa superba L.) and its application for identifying the genus

The complete chloroplast genome of two colchicine medicinal plants is reported for the first time. Deletion of ycf 15 gene occurred only in Colchicum but not in Gloriosa and suggests this as a potential marker for delineating the two species. Colchicum autumnale L. and Gloriosa superba L. are well-known sources of colchicine, a type of alkaloid and an ancient anti-inflammatory drug used to prevent gout. Accordingly, this alkaloid has been used as a chemical marker for identifying the expanded Colchicaceae family. In the present study, we report the complete chloroplast genome (cpDNA) sequence of two colchicine medicinal plants (G. superba and C. autumnale) that belong to the tribe Colchiceae of the Colchicaceae family. In C. autumnale, the circular double-stranded cpDNA sequence of 156,462 bp consists of two inverted repeat (IR) regions of 27,741 bp each, a large single-copy region (LSC) of 84,246 bp, and a small single-copy region (SSC) of 16,734 bp. The cpDNA sequence of G. superba is longer than that of C. autumnale (157,924 bp), which consists of two IRs (28,063 bp), an SSC (16,786 bp), and an LSC (85,012 bp). Significant structural differences between them were observed in the ycf15 gene. ycf15 gene was absent from C. autumnale cpDNA and affected the length of the chloroplast genome between the species. Furthermore, this gene loss event was specific to the expanded genus of Colchicum sensu Vinnersten and Manning. Therefore, this gene may be an effective and powerful molecular marker for identifying the Colchicum genus within the family.

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.

Patient Information about Gout: An International Review of Existing Educational Resources

Objective.

Inadequate patient information about gout may contribute to poor disease outcomes. We reviewed existing educational resources for gout to identify strengths and weaknesses and compare resources cross-nationally.

Methods.

Content, readability, and dietary recommendations were reviewed using a sample of 30 resources (print and Web-based) from 6 countries.

Results.

More than half of the resources were written at a highly complex level. Some content areas were lacking coverage, including comorbidity risks, uric acid target levels, and continuing allopurinol during acute attacks.

Conclusion.

Our findings suggest significant room for improvement in gout patient educational resources, particularly regarding self-management.

The economic burden of gout: A systematic review

OBJECTIVE

Gout is a painful and disabling joint disease that constitutes the most common inflammatory arthritis in the US. To clarify the economic impact of gout, we systematically reviewed the literature on the direct and indirect costs associated with this disease.

METHODS

We conducted a literature search of MEDLINE, EMBASE, International Pharmaceutical Abstracts, NHS Economic Evaluation, and CINAHL databases to identify studies of gout and economics. We systematically reviewed published studies that met our inclusion criteria and extracted and summarized all relevant economic parameters. Reported costs were inflation-adjusted to 2013 US dollars (USD).

RESULTS

A total of 15 studies met all eligibility criteria. Three controlled studies reported all-cause total direct costs based on specific populations (i.e., $4733, $16,925, and $18,362 per capita among employed, elderly, and treatment-refractory gout populations, respectively, and $2562, $10,590, and $7188 among corresponding non-gout patients). Two additional studies, although uncontrolled, allowed for estimation of total all-cause direct costs in unselected gout populations ($11,080 and $13,170). Gout-related costs ranged from $172 to $6179, depending on population characteristics. Six studies reported positive associations of direct costs with SUA level, gout attack frequency, or presence of tophi. Four studies reported on indirect costs, which were estimated to be as high as $4341 USD.

CONCLUSION

The available data suggest that gout patients incur substantially greater direct and indirect costs as compared with gout-free individuals among elderly and treatment-refractory gouty patients, whereas the costs are considerably less among younger, employed gouty patients. Further, direct costs increased with worsening disease characteristics.

Effects of anthocyanins from purple sweet potato (Ipomoea batatas L. cultivar Eshu No. 8) on the serum uric acid level and xanthine oxidase activity in hyperuricemic mice

This study was aimed at evaluating the hypouricemic effect of the anthocyanin-rich purple sweet potato extract (APSPE).

Identification of crypto- and neochlorogenic lactones as potent xanthine oxidase inhibitors in roasted coffee beans

Xanthine oxidase (XO) inhibitory activity has been found in boiling water extracts from roasted coffee beans. Therefore, assay-guided purification of the extracts was performed using size-exclusion column chromatography, and subsequently with reversed phase HPLC to afford lactone derivatives of chlorogenic acids. Among the tested lactones, crypto- and neochlorogenic lactones showed potent XO inhibitory activities compared with three major chlorogenic acids found in coffee beans. These XO inhibitory lactones may ameliorate gout and hyperuricemia in humans who drink coffee.

Uricosuric medications for chronic gout

BACKGROUND

Uricosuric agents have long been used in the treatment of gout but there is little evidence regarding their benefit and safety in this condition.

OBJECTIVES

To assess the benefits and harms of uricosuric medications in the treatment of chronic gout.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 4, 2013), Ovid MEDLINE and Ovid EMBASE for studies to the 13 May 2013. We also searched the World Health Organization Clinical Trials Registry, ClinicalTrials.gov and the 2011 to 2012 American College of Rheumatology and European League against Rheumatism abstracts. WE considered black box warnings and searched drug safety databases to identify and describe rare adverse events.

SELECTION CRITERIA

We considered all randomised controlled trials (RCTs) or quasi-randomised controlled trials (controlled clinical trials (CCTs)) that compared uricosuric medications (benzbromarone, probenecid or sulphinpyrazone) alone or in combination with another therapy (placebo or other active uric acid-lowering medication, or non-pharmacological treatment) in adults with chronic gout for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies for inclusion, extracted data and performed a risk of bias assessment. Main outcomes were frequency of acute gout attacks, serum urate normalisation, study participant withdrawal due to adverse events, total adverse events, pain reduction, function and tophus regression.

MAIN RESULTS

The search identified four RCTs and one CCT that evaluated the benefit and safety of uricosurics for gout. One study (65 participants) compared benzbromarone with allopurinol for a duration of four months; one compared benzbromarone with allopurinol (36 participants) for a duration of nine to 24 months; one study (62 participants) compared benzbromarone with probenecid for two months and one study (74 participants) compared benzbromarone with probenecid. One study (37 participants) compared allopurinol with probenecid. No study was completely free from bias.Low-quality evidence from one study (55 participants) comparing benzbromarone with allopurinol indicated uncertain effects in terms of frequency of acute gout attacks (4% with benzbromarone versus 0% with allopurinol; risk ratio (RR) 3.58, 95% confidence interval (CI) 0.15 to 84.13), while moderate-quality evidence from two studies (101 participants; treated for four to nine months) indicated similar proportions of participants achieving serum urate normalisation (73.9% with benzbromarone versus 60% with allopurinol; pooled RR 1.27, 95% CI 0.90 to 1.79). Low-quality evidence indicated uncertain differences in withdrawals due to adverse events (7.1% with benzbromarone versus 6.1% with allopurinol; pooled RR 1.25, 95% CI 0.28 to 5.62), and total adverse events (20% with benzbromarone versus 6.7% with allopurinol; RR 3.00, 95% CI 0.64 to 14.16). The study did not measure pain reduction, function and tophus regression.When comparing benzbromarone with probenecid, there was moderate-quality evidence based on one study (62 participants) that participants taking benzbromarone were more likely to achieve serum urate normalisation after two months (81.5% with benzbromarone versus 57.1% with probenecid; RR 1.43, 95% CI 1.02 to 2.00). This indicated that when compared with probenecid, five participants needed to be treated with benzbromarone in order to have one additional person achieve serum urate normalisation (number needed to treat for an additional beneficial outcome (NNTB) 5). However, the second study reported no difference in the absolute decrease in serum urate between these groups after 12 weeks. Low-quality evidence from two studies (129 participants) indicated uncertain differences between treatments in the frequency of acute gout attacks (6.3% with benzbromarone versus 10.6% with probenecid; pooled RR 0.73, 95% CI 0.09 to 5.83); fewer withdrawals due to adverse events with benzbromarone (2% with benzbromarone versus 17% with probenecid; pooled RR 0.15, 95% CI 0.03 to 0.79, NNTB 7) and fewer total adverse events (21% with benzbromarone versus 47% with probenecid; pooled RR 0.43, 95% CI 0.25 to 0.74; NNTB 4). The studies did not measure pain reduction, function and tophus regression.Low-quality evidence based on one small CCT (37 participants) indicated uncertainty around the difference in the incidence of acute gout attacks between probenecid and allopurinol after 18 to 20 months' treatment (53% with probenecid versus 55% with allopurinol; RR 0.96, 95% CI 0.53 to 1.75). The study did not measure or report the proportion achieving serum urate normalisation, pain reduction, function, tophus regression, withdrawal due to adverse events and total adverse events.

AUTHORS' CONCLUSIONS

There was moderate-quality evidence that there is probably no important difference between benzbromarone and allopurinol at achieving serum urate normalisation, but that benzbromarone is probably more successful than probenecid at achieving serum urate normalisation in people with gout. There is some uncertainty around the effect estimates, based on low-quality evidence from only one or two trials, on the number of acute gout attacks, the number of withdrawals due to adverse events or the total number of participants experiencing adverse events when comparing benzbromarone with allopurinol. However, when compared with probenecid, benzbromarone resulted in fewer withdrawals due to adverse events and fewer participants experiencing adverse events. Low-quality evidence from one small study indicated uncertain effects in the incidence of acute gout attacks when comparing probenecid with allopurinol therapy. We downgraded the evidence because of a possible risk of performance and other biases and imprecision.

Gout, allopurinol intake and clinical outcomes in the hospitalized multimorbid elderly

BACKGROUND

Increased serum uric acid has been considered a cardiovascular risk factor but no study has assessed its relation with hospital mortality or length of stay. On the basis of data obtained from a prospective registry, the prevalence of gout/hyperuricemia and its association with these and other clinical parameters was evaluated in an Italian cohort of elderly patients acutely admitted to internal medicine or geriatric wards.

METHODS

While the prevalence of gout was calculated by counting patients with this diagnosis hyperuricemia was inferred in patients taking allopurinol at hospital admission or discharge, on the assumption that this drug was only prescribed owing to the finding of high serum levels of uric acid. A series of clinical and demographic variables were evaluated for their association with gout/hyperuricemia.

RESULTS

Of 1380 patients, 139 (10%) had a diagnosis of gout or were prescribed allopurinol. They had more co-morbidities (7.0 vs 5.6; P<0.0001) and consumed more drugs (6.8 vs 5.0; P<0.0001). The CIRS (co-morbidity index) was worse in these patients (OR 1.28 95% CI 1.15-1.41). Multivariable regression analysis showed that only renal and heart failures were independently associated with gout/allopurinol intake. Moreover, this combined event was associated with an increased risk of adverse events during hospitalization (OR 1.66, 95% CI 1.16-2.36), but not with the risk of re-hospitalization, length of hospital stay or death.

CONCLUSIONS

Gout/allopurinol intake has a high prevalence in elderly patients acutely admitted to hospital and are associated with renal and cardiovascular diseases, an increased rate of adverse events and a high degree of drug consumption. In contrast, this finding did not affect the length of hospitalization nor hospital mortality.

Imaging in gout: A review of the recent developments

Gout is a common inflammatory arthritis and is caused by accumulation of monosodium urate crystals in joints and soft tissues. Apart from joint damage, untreated gout is associated with cardiovascular and renal morbidity. Gout, whilst in principle considered to be well understood and simple to treat, often presents diagnostic and management challenges, with evidence to suggest that it is often inadequately treated and poor compliance is a major issue. Imaging tools can aid clinicians in establishing the correct diagnosis, when histological crystal diagnosis is unable to be established, and also assess the burden of inflammatory and structural disease. Imaging can also be used to monitor treatment response. The imaging techniques that currently have a role in the imaging of gout include conventional radiography, ultrasound, computed tomography, dual energy computed tomography, magnetic resonance imaging and nuclear medicine. Despite the lack of major technological advances in imaging of gout in recent years, scientific studies of existing imaging modalities have improved our understanding of the disease, and how to best utilize imaging techniques in the clinical setting.

Artifacts in dual-energy CT gout protocol: a review of 50 suspected cases with an artifact identification guide

OBJECTIVE

The objective of our study was to discover the types and incidence of artifacts in dual-energy CT (DECT) using datasets of 50 consecutive patients who underwent a four-limb DECT protocol for the evaluation of suspected gout. Identification of artifacts and techniques for artifact reduction are discussed.

CONCLUSION

Artifacts commonly occur in DECT performed for gout assessment but are usually readily recognizable. For 90% of the patients in our study who underwent imaging for suspected gout, DECT showed some type of artifact, with nail bed and skin artifacts being the most common.

Identification of a potent xanthine oxidase inhibitor from oxidation of caffeic acid

Inhibitory activity of Fe-ion-catalyzed radical oxidation products from 22 types of phenolic compounds toward xanthine oxidase (XO) was investigated. Phenols are readily oxidizable compounds in nature and, thus, showed potent antioxidant activities. Among the phenols screened in this study, noticeable activity was observed in the oxidation product of caffeic acid, whereas almost no XO-inhibitory activity of caffeic acid was observed. Assay-guided purification of the oxidation product of caffeic acid afforded a highly potent XO inhibitor, with an IC50 value that was calculated to be 60 nmol L(-1), which indicated XO-inhibitory activity much stronger than that of allopurinol (IC50 = 1 μmol L(-1)), a potent XO inhibitor and excellent medicine for the treatment of gout. The chemical structure of this new XO inhibitor was investigated by one- and two-dimensional NMR and HR-ESI-MS analyses, and the unique tetracyclic structure was confirmed by synthesis starting from commercially available 1,2,4-trimethoxybenzene and 3,4-dimethoxylbenzoyl chloride.

The distribution of urate deposition within the extremities in gout: a review of 148 dual-energy CT cases

OBJECTIVE

Clinical detection of gout can be difficult due to co-existent and mimicking arthropathies and asymptomatic disease. Understanding of the distribution of urate within the body can aid clinical diagnosis and further understanding of the resulting pathology. Our aim was to determine this distribution of urate within the extremities in patients with gout.

MATERIALS AND METHODS

All patients who underwent a four-limb dual-energy computed tomography (DECT) scan for suspected gout over a 2-year period were identified (n = 148, 121 male, 27 female, age range, 16-92 years, mean = 61.3 years, median = 63 years). The reports of the positive cases were retrospectively analyzed and the locations of all urate deposition recorded and classified by anatomical location.

RESULTS

A total of 241 cases met the inclusion criteria, of which 148 cases were positive. Of these, 101 (68.2 %) patients had gout in the foot, 81 (56.1 %) in the knee, 79 (53.4 %) in the ankle, 41 (27.7 %) in the elbow, 25 (16.9 %) in the hand, and 25 (16.9 %) in the wrist. The distribution was further subcategorized for each body part into specific bone and soft tissue structures.

CONCLUSIONS

In this observational study, we provide for the first time a detailed analysis of extremity urate distribution in gout, which both supports and augments to the current understanding based on clinical and microscopic findings.

Hyperuricaemia and gout in New Zealand rural and urban Māori and non-Māori communities

BACKGROUND

There are few current data on the prevalence of hyperuricaemia and gout in New Zealand, particularly among the indigenous Māori population.

AIMS

To determine the prevalence of gout and hyperuricaemia in rural and urban Māori and non-Māori community samples and describe the treatment and comorbidities of participants with gout.

METHODS

Participants aged 20-64 years were recruited by random selection from the electoral roll. Māori samples were selected from among those identified as being of Māori descent on the roll and who self-identified as being of Māori ethnicity at interview. Personal medical history, blood pressure, anthropometrics, fasting lipids, glucose, HbA1c and urate were recorded.

RESULTS

There were 751 participants. Mean serum urate (SU) was 0.30 mmol/L (0.06-0.69 mmol/L). Māori had a significantly higher prevalence of hyperuricaemia (SU > 0.40 mmol/L) compared with non-Māori (17.0% vs 7.5%, P = 0.0003). A total of 57 participants had a history of gout, with a higher prevalence in Māori compared with non-Māori (10.3% vs 2.3%, P < 0.0001). Of the participants, 18/57 (31.6%) with gout were receiving urate-lowering therapy, but in 38.9%, SU was >0.36 mmol/L. Participants with gout were more likely to have metabolic syndrome, diabetes, cardiac disease or hypertension.

CONCLUSIONS

Gout and hyperuricaemia were more prevalent in Māori, and participants with gout were more likely to have comorbidities. There was not a higher overall adjusted cardiovascular disease risk in Māori participants with gout. Despite the high prevalence of gout, management remains suboptimal.

A revised estimate of the burden of illness of gout

Background

Gout is a chronic, inflammatory arthritis characterized by painful and debilitating acute/episodic flares. Until recently, gout has been regarded as a minor medical problem, in part because the associated economic burden has not been appreciated. Previous literature on this subject focused on the costs associated with acute episodes of gout rather than on the long-term medical and economic implications of this chronic disorder.

Objective

Our aim was to estimate the current impact of gout in the United States with respect to disability and economic costs.

Methods

The following data sources were used: published data on the incremental economic burden of gout; statistics from the US Census Bureau and the US Bureau of Labor Statistics; and recent epidemiological and clinical literature concerning the course, treatment, and outcomes of the disease. Disability is expressed as days of lost productivity. Charges for gout-related treatments were used as direct cost inputs.

Results

Gout affects an estimated 8 million Americans, among whom those working have an average of almost 5 more absence days annually than workers without gout. On average, the incremental annual cost of care for a gout patient is estimated at >$3000 compared with a nongouty individual. Even though comorbidities common in gout patients account for a portion of this increased economic burden, the total annual cost attributable to gout patients in the United States is likely in the tens of billions of dollars and comparable to those of other major chronic disorders, such as migraine and Parkinson’s disease.

Conclusions

The economic burden of gout is most readily assessable in patients whose acute arthritic flares result in emergency department visits, bedridden days, and episodic loss of productivity. Chronic progression of the disease can also result in long-term impairment of function and health-related quality of life, but the contribution of chronic gout to the economic burden is more difficult to quantitate because gout is frequently associated with serious cardiovascular, metabolic, and renal comorbidities. Recent demonstration that successful gout management can reverse functional deficits in many chronic gout patients, however, supports the views that chronic gout contributes substantially to the medical and thus economic costs of these patients and that early and aggressive efforts to improve gout outcomes are likely to reduce the associated economic burden.

Effectiveness of a pharmacist-based gout care management programme in a large integrated health plan: results from a pilot study

OBJECTIVES

The study objective was to determine the feasibility of using a pharmacist-staffed, protocol-based structured approach to improving the management of chronic, recurrent gout.

SETTING

The study was carried out in the outpatient clinic of a single Kaiser Permanente medical centre. This is a community-based clinic.

PARTICIPANTS

We report on 100 consecutive patients between the ages of 21 and 94 (75% men) with chronic or recurrent gout, referred by their primary physicians for the purpose of management of urate-lowering therapy. Patients with stage 5 chronic kidney disease or end-stage kidney disease were excluded.

INTERVENTIONS

The programme consisted of a trained clinical pharmacist and a rheumatologist. The pharmacist contacted each patient by phone, provided educational and dietary materials, and used a protocol that employs standard gout medications to achieve and maintain a serum uric acid (sUA) level of 6 mg/dL or less. Incident gout flares or adverse reactions to medications were managed in consultation with the rheumatologist.

PRIMARY OUTCOME MEASURE

The primary outcome measure was the achievement and maintenance of an sUA of 6 or less for a period of at least 3 months.

RESULTS

In 95 evaluable patients enrolled in our pilot programme, an sUA of 6 mg/dL or less was achieved and maintained in 78 patients with 4 still in the programme to date. Five patients declined to participate after referral, and another 13 patients did not complete the programme. (The majority of these were due to non-adherence.)

CONCLUSIONS

A structured pharmacist-staffed programme can effectively and safely lower and maintain uric acid levels in a high percentage of patients with recurrent gout in a primary care setting. This care model is simple to implement, efficient and warrants further validation in a clinical trial.

Comorbidity burden, healthcare resource utilization, and costs in chronic gout patients refractory to conventional urate-lowering therapy

Patients with chronic gout refractory to conventional urate-lowering therapy have high rates of flares and incidence of tophi, which impose a significant disease and potentially economic burden. This study examined healthcare resource use and costs stratified by disease burden. Adult patients diagnosed with gout (ICD-9-CM:274.xx) and having had ≥3 flares defined by clinical surrogates within a 12-month period were selected for the case cohort from the Thomson MarketScan databases (2003/Q3-2008/Q3). Only patients who had received allopurinol treatment and a diagnosis of tophi (ICD-9-CM:274.8x) at any time before the first flare (index date) or within 12 months postindex were included and were matched in a 1:1 ratio with control gout-free subjects. The comorbidity burden, healthcare resource use, and annual healthcare costs (2008 US$) in the 12-month postindex period were compared between both cohorts using regression models adjusted for demographic characteristic and stratified for patients with ≥6 flares. A total of 679 gout patients met the inclusion criteria for the study and had a higher prevalence of comorbidities than their matched controls. Gout cohort had a significantly higher incidence of emergency room, hospitalizations, outpatient visits, and other medical services than did their matched controls (all comparisons, uncorrected P < 0.01). After adjusting for baseline characteristics, the refractory gout cohort incurred an incremental total annual healthcare cost of $10,222 where 40% of the annual medical cost was for gout-related care compared with control cohort (P < 0.01). Patients with refractory gout have a significant economic burden compared with a gout-free population.

Primary care providers' knowledge, beliefs and treatment practices for gout: results of a physician questionnaire

OBJECTIVE

We sought to examine primary care providers' gout knowledge and reported treatment patterns in comparison with current treatment recommendations.

METHODS

We conducted a national survey of a random sample of US primary care physicians to assess their treatment of acute, intercritical and tophaceous gout using published European and American gout treatment recommendations and guidelines as a gold standard.

RESULTS

There were 838 respondents (response rate of 41%), most of whom worked in private practice (63%) with >16 years experience (52%). Inappropriate dosing of medications in the setting of renal disease and lack of prophylaxis when initiating urate-lowering therapy (ULT) accounted for much of the lack of compliance with treatment recommendations. Specifically for acute podagra, 53% reported avoidance of anti-inflammatory drugs in the setting of renal insufficiency, use of colchicine at a dose of ≤2.4 mg/day and no initiation of a ULT during an acute attack. For intercritical gout in the setting of renal disease, 3% would provide care consistent with the recommendations, including initiating a ULT at the appropriate dose with dosing titration to a serum urate level of ≤6 mg/dl and providing prophylaxis. For tophaceous gout, 17% reported care consistent with the recommendations, including ULT use with dosing titration to a serum urate level of ≤6 mg/dl and prophylaxis.

CONCLUSION

Only half of primary care providers reported optimal treatment practices for the management of acute gout and <20% for intercritical or tophaceous gout, suggesting that care deficiencies are common.

Dose-response association of uncontrolled blood pressure and cardiovascular disease risk factors with hyperuricemia and gout

BACKGROUND

First-line therapy of hypertension includes diuretics, known to exert a multiplicative increase on the risk of gout. Detailed insight into the underlying prevalence of hyperuricemia and gout in persons with uncontrolled blood pressure (BP) and common comorbidities is informative to practitioners initiating antihypertensive agents. We quantify the prevalence of hyperuricemia and gout in persons with uncontrolled BP and additional cardiovascular disease (CVD) risk factors.

METHODS AND FINDINGS

We performed a cross-sectional study of non-institutionalized US adults, 18 years and older, using the National Health and Nutrition Examination Surveys in 1988-1994 and 1999-2010. Hyperuricemia was defined as serum uric acid >6.0 mg/dL in women; >7.0 mg/dL in men. Gout was ascertained by self-report of physician-diagnosed gout. Uncontrolled BP was based on measured systolic BP≥140 mmHg and diastolic BP≥90 mmHg. Additional CVD risk factors included obesity, reduced glomerular filtration rate, and dyslipidemia. The prevalence of hyperuricemia was 6-8% among healthy US adults, 10-15% among adults with uncontrolled BP, 22-25% with uncontrolled BP and one additional CVD risk factor, and 34-37% with uncontrolled BP and two additional CVD risk factors. Similarly, the prevalence of gout was successively greater, at 1-2%, 4-5%, 6-8%, and 8-12%, respectively, across these same health status categories. In 2007-2010, those with uncontrolled BP and 2 additional CVD risk factors compared to those without CVD risk factors had prevalence ratios of 4.5 (95% CI 3.5-5.6) and 4.5 (95% CI: 3.1-6.3) for hyperuricemia and gout respectively (P<0.01).

CONCLUSIONS

Health care providers should be cognizant of the incrementally higher prevalence of hyperuricemia and gout among patients with uncontrolled BP and additional CVD risk factors. With one in three people affected by hyperuricemia among those with several CVD risk factors, physicians should consider their anti-hypertensive regimens carefully and potentially screen for hyperuricemia or gout.

Rates of adherence and persistence with allopurinol therapy among gout patients in Israel

OBJECTIVE

To assess the adherence and persistence with allopurinol therapy among gout patients and to identify risk factors for therapy discontinuation.

METHODS

The study population included adults in Maccabi Healthcare Services, a 2-million member health maintenance organization in Israel, who were diagnosed with gout between 2002 and 2008. Adherence with allopurinol was retrospectively assessed by calculating the proportion of days covered of dispensed prescriptions. Persistence was assessed by calculating the mean proportion of follow-up days covered with allopurinol for every study participant.

RESULTS

A total of 7644 patients were identified. Among men, the incidence of gout was strongly associated with age, ranging from 0.5 per 1000 among adults younger than 45 years to more than 36 per 1000 among elderly men aged 85 or older). A total of 1331 gout patients (17% of the study population) were adherent to allopurinol therapy, 36% and 47% had partial and poor adherence, respectively. Persistence analysis indicated that the average duration until therapy was discontinued was similar among men (358 days) and women (379 days). Women aged 45-64 years, non-married individuals, those of low socioeconomic status and those with lower body weight were more likely to discontinue therapy. Logistic regression (n = 2471, 32% of the study sample) showed a 4.5 risk of non-compliance among 45- to 65-year-old women. Better compliance was achieved among those with comorbidities, particularly among patients with concomitant cardiovascular disease.

CONCLUSION

Only one out of six gout patients is adherent with allopurinol. Intervention programmes to increase adherence with treatment should focus on high-risk populations.

Resource use and economic impact of patients with gout: a multicenter, population-wide study

OBJECTIVE

To determine the use of resources and economic impact of patients with gout at the population level.

PATIENTS AND METHODS

Observational design analysing records belonging to 6 primary care centers and 2 hospitals. We included patients' ≥18 years with an acute episode of gout over the years 2003-2007. Patient follow-up was 2 years. It produced two study groups: patients with 1-2 attacks/acute recurrences and 3 or more events. Main variables were: demographic, co-morbidity, metabolic syndrome (MS), and resource use and health/non-health costs.

STATISTICAL ANALYSIS

logistic regression-model ANCOVA, P<.05.

RESULTS

3,130 patients with gout were included. Prevalence: 3.3%, mean age: 55.8 years male: 81.1%. Groups were distributed as follows: 68.4% had 1-2 acute attacks and 31.6% with 3 or more, P<.001. The prevalence of MS was 28.8% (confidence interval [CI] 95% CI 27.2 to 30.4%). The average/unit cost was € 2,228.6 (direct costs: 96.9%), 90.8% in primary care (visits: 23.5%; drugs: 57.7%). For groups, the average corrected model/unit total cost per patient was € 2,130.6 vs. € 2,605.4, respectively (P<.001). In all cost components, the results were higher in the group with ≥ 3 attacks. The subgroup of diabetic patients (N=641, 20.5%) had a higher cost (€ 3,124.8€ vs. € 1,997.8, P<.001).

CONCLUSIONS

Gout is associated with substantial morbidity, presence of MS and resource consumption. The study provides useful data on the cost of the disease; the costs of outpatient follow up is the highest.

Female gout: age and duration of the disease determine clinical presentation

OBJECTIVE

This study aimed to compare data and associated diseases between women and men with gout paired for age and duration of the disease.

METHODS

Consecutive patients from outpatient gout clinics of 2 rheumatology departments were included in this case-control study. We identified 37 women with gout diagnosis and paired them by age and duration of the disease with 37 men with gout (American College of Rheumatology criteria). Variables were clinical data, associated diseases, and renal function evaluated by 3 methods: creatinine clearance, modification of diet in renal disease, and Cockcroft-Gault.

RESULTS

Mean (SD) age was 54.47 (15.13) years in women versus 53.52 (15.23) years in males, and mean (SD) age at onset 46.77 (16.63) years versus 45.62 (16.16) years in women and men, respectively. Hypertension was found in 26 (73%) of 37 women and in 27 (70%) of 37 men, previous diuretics was found in only 1 man, and no significant differences were found between women and men in gout or associated metabolic diseases. Females had lower creatinine clearance than males did (49.8 [29.7] vs. 67.1 [35.5] mL/min, P = 0.039). But, when it was calculated by methods considering sex, there were no significant differences (Cockcroft-Gault 66.4 [37.6] vs. 78.8 [43.8] mL/min [P = 0.2] and modification of diet in renal disease 73.8 [64.6] vs. 73.1 [35.0] mL/min [P = 0.9], females vs. males, respectively). Thirteen women (35%) were premenopausal at onset, 2 had familial history of gout, and 2 had history of lithiasis; other variables were not different from postmenopausal women.

CONCLUSIONS

Factors previously associated to female gout seem to be more related to age than to sex or to the disease itself. In our country, patients with gout (males and females) are younger at onset. Gender should be considered to evaluate renal function in females with gout. One third of our female patients with gout were premenopausal and had unexpected higher frequency of lithiasis; no other differences with postmenopausal women were found.

Lead optimization of isocytosine-derived xanthine oxidase inhibitors

We report our attempts at improving the oral efficacy of low-nanomolar inhibitors of xanthine oxidase from isocytosine series through chemical modifications. Our lead compound had earlier shown good in vivo efficacy when administered intraperitoneally but not orally. Several modifications are reported here which achieved more than twofold improvement in exposure. A compound with significant improvement in oral efficacy was also obtained.

Latest evidence on gout management: what the clinician needs to know

Until recently, the last drug approved for the treatment of gout by the United States Food and Drug Administration was allopurinol in 1966. Since 2008, two new drugs for the treatment of gout, febuxostat and pegloticase, have been approved in the US. Febuxostat has been approved in the EU and pegloticase approval is anticipated. A new single-ingredient colchicine preparation is available in the US, and the treatment recommendations for the use of colchicine in acute gout have evolved, now favoring a low-dose regimen. Several other exciting drugs are in development. Herein, we review some of basic principles in the diagnosis and staging of gout. We then examine current treatment principles, with particular attention to febuxostat and pegloticase, offering suggestions as to where they might fit into a modern therapeutic algorithm for gout treatment. We then present available data on several exciting new agents in development, including interleukin-1 inhibitors, and relate them to advances in our understanding of gout pathogenesis. We conclude with some important nonpharmacologic principles for optimal management of this ancient and eminently treatable disease. Dedicated gout research, going on quietly in the background of other breathtaking advances in rheumatology, is now paying off. This comes at a time when the number of patients affected by gout continues to rise, mainly due to an epidemic of obesity. An effort to improve lifestyle choices as a society and better management of the disease by clinicians should have a positive impact on gout incidence and outcome in our lifetimes.

Isocytosine-based inhibitors of xanthine oxidase: design, synthesis, SAR, PK and in vivo efficacy in rat model of hyperuricemia

Structure-activity relationship studies were carried out for lead generation following structure-guided design approach from an isocytosine scaffold identified earlier for xanthine oxidase inhibition. A 470-fold improvement in in vitro IC(50) was obtained in the process. Five most potent compounds with nanomolar IC(50) values were selected for pharmacokinetics and in vivo experiments. The best compound showed good in vivo activity when administered intraperitoneally but was not active by oral route. The results suggest that improvement in oral exposure could improve the in vivo efficacy of this series.

Management strategies for osteoarthritis, ankylosing spondylitis, and gouty arthritis

Rheumatic diseases are among the most frequent causes of pain and disability. Effective management of rheumatic diseases including osteoarthritis (OA), ankylosing spondylitis (AS), and gouty arthritis requires an understanding of the underlying disease mechanisms.Symptoms of OA result from both mechanical factors and elements of inflammation. Current management strategies target both of these factors and generally consist of nonpharmacologic and pharmacologic interventions, including use of nonspecific nonsteroidal antiinflammatory drugs (NSAIDs) and cyclooxygenase-2-specific inhibitors (coxibs), which have analgesic and antiinflammatory properties. Other approaches include intraarticular hyaluronate and the use of alternative therapies under investigation such as acupuncture or glucosamine.Disease mechanisms in AS involve enthesitis, an inflammation at the site of insertion of ligaments, tendons, or joint capsules to bone. Posture and exercise are important nonpharmacologic strategies that may be made easier with the use of NSAIDs or coxibs. Recently developed therapies, including tumor necrosis factor inhibitors, target the underlying disease mechanisms and have demonstrated dramatic symptomatic effects. Disease-modifying effects still need to be established.In gout, hyperuricemia leads to crystal-induced inflammation in some patients. Etoricoxib, one of the newer coxibs, has shown promise in treating acute gout, with efficacy similar to indomethacin, the current standard NSAID often used in these patients. Oral or intraarticular steroids can also be considered. For chronic care uricosurics can be beneficial if renal function is normal and excretion is not excessive, but allopurinol is used most often. Nonpharmacologic modalities, such as rest and cold applications, are useful for acute episodes, and lifestyle modification in the form of diet can also play a role in chronic disease management.

Tophi and frequent gout flares are associated with impairments to quality of life, productivity, and increased healthcare resource use: Results from a cross-sectional survey

Background

The prevalence of gout is increasing, and most research on the associated burden has focused on serum urate (sUA) levels. The present study quantifies the impact of the presence of tophi and frequency of acute gout attacks on health-related quality of life (HRQOL), productivity, and healthcare resource utilization.

Methods

Patients with self-reported gout (n = 620; 338 in US and 282 across France, Germany, and UK) were contacted based on inclusion in the 2010 US and EU National Health and Wellness Surveys (Kantar Health) and the Lightspeed Research ailment panel. Respondents were categorized into mutually-exclusive groups based on number of gout flares experienced in the past 12 months (0/don’t recall, 1–2, 3, 4–5, 6+), current presence of tophi (none, 1+, or not sure), and sUA level awareness (yes, no). HRQOL (SF-12v2), healthcare provider visits in the last 6 months, and work productivity and activity impairment (WPAI) were compared across groups.

Results

Most patients were males, mean age of 61 years, who reported experiencing at least one acute gout flare in the past 12 months, and 12.3% (n = 76) reported presence of tophi. Among the 27.7% (n = 172) of patients who were aware of their sUA levels, higher sUA was associated with more flares and tophi. Decreased HRQOL was associated with more frequent flares and presence of tophi. In multivariable models predicting outcomes based on presence of tophi and number of flares, both flares (≥4) and tophi (≥1) were associated with HRQOL decrements on physical and mental component summary scores and health utilities (all p < 0.05), after adjustment for age, gender, and time since diagnosis. Flares were also associated with greater activity impairment.

Conclusions

Impairments associated with gout flares and presence of tophi, across patients in the US and EU, underscore the importance of effective management of this potentially curable condition.