Gout and dementia in the elderly: a cohort study of Medicare claims

Sex Differences in the Preventive Effect of Cardiovascular and Metabolic Therapeutics on Dementia

Dementia is a clinical syndrome characterized by progressive impairment of cognitive and functional abilities. As currently applied treatments for dementia can only delay the progression of dementia and cannot fundamentally cure it, much attention is being paid to reducing its incidence by preventing the associated risk factors. Cardiovascular and metabolic diseases are well-known risk factors for dementia, and many studies have attempted to prevent dementia by treating these risk factors. Growing evidence suggests that sex-based factors may play an important role in the pathogenesis of dementia. Therefore, a deeper understanding of the differences in the effects of drugs based on sex may help improve their effectiveness. In this study, we reviewed sex differences in the impact of therapeutics targeting risk factors for dementia, such as cardiovascular and metabolic diseases, to prevent the incidence and/or progression of dementia.

The Role of Uric Acid in Human Health: Insights from the Uricase Gene

Uric acid is the final product of purine metabolism and is converted to allantoin in most mammals via the uricase enzyme. The accumulation of loss of function mutations in the uricase gene rendered hominoids (apes and humans) to have higher urate concentrations compared to other mammals. The loss of human uricase activity may have allowed humans to survive environmental stressors, evolution bottlenecks, and life-threatening pathogens. While high urate levels may contribute to developing gout and cardiometabolic disorders such as hypertension and insulin resistance, low urate levels may increase the risk for neurodegenerative diseases. The double-edged sword effect of uric acid has resurrected a growing interest in urate's antioxidant role and the uricase enzyme's role in modulating the risk of obesity. Characterizing both the effect of uric acid levels and the uricase enzyme in different animal models may provide new insights into the potential therapeutic benefits of uric acid and novel uricase-based therapy.

Gout and risk of dementia, Alzheimer's disease or vascular dementia: a meta-epidemiology study

Objectives

The association between gout and dementia, Alzheimer's disease (AD), or vascular dementia (VD) is not fully understood. The aim of this meta-analysis was to evaluate the risk of all-cause dementia, AD, and VD in gout patients with or without medication.

Methods

Data sources were PubMed, Embase, the Cochrane Library, and reference lists of included studies. This meta-analysis included cohort studies assessing whether the risk of all-cause dementia, AD, and VD was associated with gout. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was used to access the overall certainty of evidence. Risk ratios (RR) with 95% confidence intervals (CI) were pooled using a random-effects model, and publication bias was assessed with funnel plots and Egger's test.

Results

A total of six cohort studies involving 2,349,605 individuals were included in this meta-analysis, which were published between 2015 and 2022. The pooling analysis shows that the risk of all-cause dementia was decreased in gout patients [RR = 0.67, 95% CI (0.51, 0.89), I2 = 99%, P = 0.005, very low quality], especially in gout patients with medication [RR = 0.50, 95% CI (0.31, 0.79), I2 = 93%, P = 0.003, low quality]. The risk of AD [RR = 0.70, 95% CI (0.63, 0.79), I2 = 57.2%, P = 0.000, very low quality] and VD [RR = 0.68, 95% CI (0.49, 0.95), I2 = 91.2%, P = 0.025, very low quality] was also decreased in gout patients. Despite the large heterogeneity, the sensitivity analysis indicated that the results were robust, and there was little evidence of publication bias.

Conclusion

The risk of all-cause dementia, AD, and VD is decreased in gout patients, but the quality of evidence is generally low. More studies are still needed to validate and explore the mechanisms of this association.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022353312.

Cause-Specific Mortality in Patients With Gout in the US Veterans Health Administration: A Matched Cohort Study

OBJECTIVE

To compare all-cause and cause-specific mortality risk between patients with gout and patients without gout in the Veteran's Health Administration (VHA).

METHODS

We performed a matched cohort study, identifying patients with gout in the VHA from January 1999 to September 2015 based on the presence of ≥2 International Classification of Diseases, Ninth Revision codes for gout (274.X). Gout patients were matched up to 1:10 on birth year, sex, and year of VHA enrollment with patients without gout and followed until death or end of study (December 2017). Cause of death was obtained from the National Death Index. Associations of gout with all-cause and cause-specific mortality were examined using multivariable Cox regression.

RESULTS

Gout (n = 559,243) and matched non-gout controls (n = 5,428,760) had a mean age of 67 years and were 99% male. There were 246,291 deaths over 4,250,371 patient-years in gout patients and 2,000,000 deaths over 40,441,353 patient-years of follow-up in controls. After matching, gout patients had an increased risk of death (hazard ratio [HR] 1.09 [95% confidence interval (95% CI) 1.08-1.09]), which was no longer present after adjusting for comorbidities (HR 0.98 [95% CI 0.97-0.98]). The strongest association of gout with cause-specific mortality was observed with genitourinary conditions (HR 1.50 [95% CI 1.47-1.54]). Gout patients were at lower risk of death related to neurologic (e.g., Alzheimer's disease and Parkinson's disease) (HR 0.63 [95% CI 0.62-0.65]) and mental health (HR 0.66 [95% CI 0.65-0.68]) conditions.

CONCLUSION

A higher risk of death among gout patients in the VHA was related to comorbidity burden. While deaths attributable to neurologic and mental health conditions were less frequent among gout patients, genitourinary conditions were the most overrepresented causes of death.

Association between gout at midlife and cognitive impairment at late life - The Singapore Chinese Health Study

OBJECTIVES

The association between gout and risk of cognitive impairment or dementia is not well established. We examined the relationship between having gout at midlife and the risk of developing cognitive impairment later on.

METHODS

We used data of 16,948 participants from the population-based Singapore Chinese Health Study cohort. Participants were recruited from 1993 to 1998 at mean age of 53 years and re-contacted for three follow-up interviews: 1999 to 2004 for follow-up 1, 2006 to 2010 for follow-up 2, and 2014 to 2016 for follow-up 3. History of physician-diagnosed gout was self-reported at follow-up 1 and follow-up 2, while cognitive function was assessed with the Singapore modified Mini-Mental State Examination during follow-up 3, when participants had a mean age of 73.2 years.

RESULTS

Gout was reported by 1281 (7.6%) participants at either follow-up 1 or 2, and 2243 (14.4%) had cognitive impairment at follow-up 3. A history of gout was associated with reduced risk of cognitive impairment (OR 0.78, 95% CI 0.65-0.93). This risk was reduced in a stepwise manner with either increased duration of gout or lower age at first diagnosis of gout (P_trend <0.001). Compared to those without gout, those with gout for ≥20 years (OR 0.56, 95% CI 0.39-0.80) and those with age of onset of gout <50 years old (OR 0.59, 95% CI 0.37-0.94) had a lower risk of developing cognitive impairment.

CONCLUSION

A young age of onset or a long history of gout was associated with reduced risk of cognitive impairment in late life.

Longitudinal follow-up study of the association with gout and Alzheimer's disease and Parkinson's disease in Korea

To date, no clear conclusion on the relationships of gout with the occurrence of typical neurodegenerative diseases, Alzheimer's disease (AD) and Parkinson's disease (PD), has been reached. This study aimed to determine whether the patients with gout are at a lower or higher probability of developing AD or PD than those without gout. Longitudinal follow-up data of a representative sample of Korean adults were assessed. 18,079 individuals diagnosed with gout between 2003 and 2015 were enrolled in the gout group. The comparison group comprised 72,316 demographics-matched individuals not diagnosed with gout. Longitudinal associations of gout with AD or PD were estimated using Cox proportional hazard regression adjusting for potential confounders. The adjusted hazard ratios (HRs) of AD and PD in the gout group were 1.01 and 1.16 times higher than controls, but these differences were not statistically significant (95% confidence interval [CI] = 0.92-1.12 and 95% CI = 0.97-1.38, respectively). Although there was no significant association in the entire sample, AD and PD probabilities in patients with gout were significantly higher in participants < 60 years, and PD probabilities in patients with gout were significantly higher in overweight participants. Our findings identify significant correlations of gout with AD and PD in participants < 60 years and gout with PD in those with overweight, indicating that gout may play a role in the development of neurodegenerative diseases in younger or overweight populations. Further investigations should be performed to corroborate these findings.

Could Alzheimer's disease be a maladaptation of an evolutionary survival pathway mediated by intracerebral fructose and uric acid metabolism?

An important aspect of survival is to assure enough food, water, and oxygen. Here, we describe a recently discovered response that favors survival in times of scarcity, and it is initiated by either ingestion or production of fructose. Unlike glucose, which is a source for immediate energy needs, fructose metabolism results in an orchestrated response to encourage food and water intake, reduce resting metabolism, stimulate fat and glycogen accumulation, and induce insulin resistance as a means to reduce metabolism and preserve glucose supply for the brain. How this survival mechanism affects brain metabolism, which in a resting human amounts to 20% of the overall energy demand, is only beginning to be understood. Here, we review and extend a previous hypothesis that this survival mechanism has a major role in the development of Alzheimer's disease and may account for many of the early features, including cerebral glucose hypometabolism, mitochondrial dysfunction, and neuroinflammation. We propose that the pathway can be engaged in multiple ways, including diets high in sugar, high glycemic carbohydrates, and salt. In summary, we propose that Alzheimer's disease may be the consequence of a maladaptation to an evolutionary-based survival pathway and what had served to enhance survival acutely becomes injurious when engaged for extensive periods. Although more studies are needed on the role of fructose metabolism and its metabolite, uric acid, in Alzheimer's disease, we suggest that both dietary and pharmacologic trials to reduce fructose exposure or block fructose metabolism should be performed to determine whether there is potential benefit in the prevention, management, or treatment of this disease.

Prevalence of motor neuron diseases in gout patients: a nationwide population-based cohort study

BACKGROUND

Increased uric acid may have a protective effect in motor neuron diseases (MNDs). The association between gout, characterized by hyperuricemia, and MNDs was not investigated previously. To estimate the prevalence of MNDs in gout patients using the Health Insurance and Review Assessment (HIRA) database, a nationwide database of South Korea.

METHODS

The current descriptive study was conducted using the HIRA database. Subjects diagnosed with gout from 2011 to 2018 were included in this study. Among them, the annual prevalence of MNDs was analyzed, stratified by age and sex. Comorbidities including the Charlson Comorbidity Index score and type of prescribed gout-related drug were also demonstrated.

RESULTS

The age-adjusted prevalence of MNDs per 10⁵ persons ranged from 0.598 (95% confidence interval (CI): - 0.231-1.426) to 2.534 (95% CI: 1.100-3.968) between 2011 and 2018. Compared to previous reports, the prevalence of MNDs, especially amyotrophic lateral sclerosis (ALS), in gout patients was significantly lower than in the general population. None of the female gout patients were diagnosed with MNDs. Cerebrovascular accidents, vascular risk factors including hypertension, dyslipidemia, and diabetic complications, and the use of uric acid-lowering agents were more common in gout patients with MNDs than in those without MNDs.

CONCLUSION

This study adds to the evidence of MND prevalence in gout patients. Gout might have a protective effect against the risk of MNDs.

Association between urate-lowering therapies and cognitive decline in community-dwelling older adults

Long-term use of urate-lowering therapies (ULT) may reduce inflammaging and thus prevent cognitive decline during aging. This article examined the association between long-term use of ULT and cognitive decline among community-dwelling older adults with spontaneous memory complaints. We performed a secondary observational analysis using data of 1673 participants ≥ 70 years old from the Multidomain Alzheimer Preventive Trial (MAPT Study), a randomized controlled trial assessing the effect of a multidomain intervention, the administration of polyunsaturated fatty acids (PUFA), both, or placebo on cognitive decline. We compared cognitive decline during the 5-year follow-up between three groups according to ULT (i.e. allopurinol and febuxostat) use: participants treated with ULT during at least 75% of the study period (PT ≥ 75; n = 51), less than 75% (PT < 75; n = 31), and non-treated participants (PNT; n = 1591). Cognitive function (measured by a composite score) was assessed at baseline, 6 months and every year for 5 years. Linear mixed models were performed and results were adjusted for age, sex, body mass index (BMI), diagnosis of arterial hypertension or diabetes, baseline composite cognitive score, and MAPT intervention groups. After the 5-year follow-up, only non-treated participants presented a significant decline in the cognitive composite score (mean change - 0.173, 95%CI - 0.212 to - 0.135; p < 0.0001). However, there were no differences in change of the composite cognitive score between groups (adjusted between-group difference for PT ≥ 75 vs. PNT: 0.144, 95%CI - 0.075 to 0.363, p = 0.196; PT < 75 vs. PNT: 0.103, 95%CI - 0.148 to 0.353, p = 0.421). Use of ULT was not associated with reduced cognitive decline over a 5-year follow-up among community-dwelling older adults at risk of dementia.

Moderate increase of serum uric acid within a normal range is associated with improved cognitive function in a non-normotensive population: A nationally representative cohort study

Background

Associations between serum uric acid (SUA) and changes in cognitive function are understudied in non-normotensive populations, and many previous studies only considered the baseline SUA at a single time point. We aimed to examine the effects of baseline SUA and 4-year changes in SUA on cognitive changes in the non-normotensive population.

Materials and methods

In the China Health and Retirement Longitudinal Study (CHARLS), cognitive function was measured based on executive function and episodic memory in four visits (years: 2011, 2013, 2015, and 2018). We identified two study cohorts from CHARLS. The first cohort included 3,905 non-normotensive participants. Group-based single-trajectory and multi-trajectory models were applied to identify 7-year cognitive trajectories. Adjusted ordinal logistics models were performed to assess the association between baseline SUA and 7-year cognitive trajectories, and subgroup analyses were conducted according to the presence of hyperuricemia or SUA levels. The second cohort included 2,077 eligible participants. Multiple linear regression was used to explore the effect of a 4-year change in SUA on cognitive change during the subsequent 3-year follow-up.

Results

Four distinct single-trajectories of global cognitive performance and four multi-trajectories of executive function and episodic memory were identified. Higher baseline SUA levels were significantly associated with more favorable cognitive single-trajectories (OR_{Q4 vs}. _Q1: 0.755; 95% CI: 0.643, 0.900) and multi-trajectories (OR_{Q4 vs}. _Q1: 0.784; 95% CI: 0.659, 0.933). Subgroup analyses revealed that the protective effect of SUA was significant in the non-hyperuricemia groups or the low-level SUA groups. Additionally, changes in SUA could influence future cognitive changes. Compared with non-hyperuricemia participants with elevated SUA, non-hyperuricemia participants with decreased SUA and patients with persistent hyperuricemia had a higher risk for cognitive decline. Furthermore, only the Q3 group of changes in SUA could enhance global cognitive function compared with the Q1 group (β: 0.449; 95% CI: 0.073, 0.826).

Conclusion

Our study indicates that the maintenance of normal SUA levels and a moderate increase of SUA were advantageous in improving cognitive function or trajectories in a non-normotensive population. Conversely, SUA may impair cognitive function in patients with persistent hyperuricemia.

The Association of Serum Uric Acid Level, Gout, and Alzheimer's Disease: A Bidirectional Mendelian Randomization Study

BACKGROUND

The relationship between serum uric acid (UA) and Alzheimer's disease (AD) risk still remained ambiguous despite extensive attempts.

OBJECTIVE

Via the two-sample Mendelian randomization (MR) design, we aimed to examine the bidirectional causal relationships of serum UA, gout, and the risk of AD.

METHODS

Genetic variants of UA, gout, and AD were extracted from published genome-wide association summary statistics. The inverse-variance weighted (IVW, the primary method), and several sensitivity methods (MR-Egger, weighted median, and weighted mode) were used to calculate the effect estimates. Egger regression, MR-PRESSO and leave-one-SNP-out analysis were performed to identify potential violations.

RESULTS

Genetic proxies for serum UA concentration [odds ratio (ORIVW) = 1.09, 95% confidence interval (CI) = 1.01-1.19, p = 0.031] were related with an increased risk of AD using 25 single nucleotide polymorphisms (SNPs). This causal effect was confirmed by sensitivity analyses including MR-Egger (1.22, 1.06-1.42, p = 0.014), weighted median (1.18, 1.05-1.33, p = 0.006), and weighted mode (1.20, 1.07-1.35, p = 0.005) methods. No evidence of notable directional pleiotropy and heterogeneity were identified (p >  0.05). Three SNPs (rs2078267, rs2231142, and rs11722228) significantly drove the observed causal effects. Supportive causal effect of genetically determined gout on AD risk was demonstrated using two SNPs (ORIVW = 1.05, 95% CI = 1.00-1.11, p = 0.057). No reverse causal effects of AD on serum UA levels and gout risk were found.

CONCLUSION

The findings revealed a causal relationship between elevated serum UA level and AD risk. However, further research is still warranted to investigate whether serum UA could be a reliable biomarker and therapeutic target for AD.

Association Between Gout and Dementia in the Elderly: A Nationwide Population-Based Cohort Study

OBJECTIVE

The data showing the association between gout and dementia are inconsistent. The objective of this study was to examine whether gout is associated with the risk of dementia in the elderly.

METHODS

This retrospective cohort study used population-based representative claims data from the National Health Insurance Service in Korea. We used the Elderly Cohort database which represents 10% of the elderly Koreans over the age of 60, from 2002 to 2013. We assessed the association of gout with a new diagnosis of dementia with Cox proportional hazard models and adjusted the data for potential covariates such as demographics (age, sex) and comorbidities.

RESULTS

We included 22,178 patients with gout and 113,590 without. In each group, 2,557 (11.53%) and 18,264 (16.08%) patients, respectively, had dementia. In multivariable analyses, gout was independently associated with a significantly lower hazard ratio of incident dementia, with an adjusted hazard ratio of 0.63 (95% CI, 0.60-0.66). A sub-group analysis conducted to find out the effects of gout medication showed that febuxostat use significantly decreased incident dementia.

CONCLUSION

Gout was independently associated with a 37% lower risk of dementia in the elderly.

High Blood Uric Acid Is Associated With Reduced Risks of Mild Cognitive Impairment Among Older Adults in China: A 9-Year Prospective Cohort Study

Background: It remains unsolved that whether blood uric acid (UA) is a neuroprotective or neurotoxic agent. This study aimed to evaluate the longitudinal association of blood UA with mild cognitive impairment (MCI) among older adults in China.

Methods: A total of 3,103 older adults (aged 65+ years) free of MCI at baseline were included from the Healthy Aging and Biomarkers Cohort Study (HABCS). Blood UA level was determined by the uricase colorimetry assay and analyzed as both continuous and categorical (by quartile) variables. Global cognition was assessed using the Mini-Mental State Examination four times between 2008 and 2017, with a score below 24 being considered as MCI. Cox proportional hazards models were used to examine the associations.

Results: During a 9-year follow-up, 486 (15.7%) participants developed MCI. After adjustment for all covariates, higher UA had a dose-response association with a lower risk of MCI (all P_{for  trend} < 0.05). Participants in the highest UA quartile group had a reduced risk [hazard ratio (HR), 0.73; 95% (CI): 0.55–0.96] of MCI, compared with those in the lowest quartile group. The associations were still robust even when considering death as a competing risk. Subgroup analyses revealed that these associations were statistically significant in younger older adults (65–79 years) and those without hyperuricemia. Similar significant associations were observed when treating UA as a continuous variable.

Conclusions: High blood UA level is associated with reduced risks of MCI among Chinese older adults, highlighting the potential of managing UA in daily life for maintaining late-life cognition.

Risk of dementia in gout and hyperuricaemia: a meta-analysis of cohort studies

OBJECTIVES

Gout, characterised by hyperuricaemia with monosodium urate crystal formation and inflammation, is the most common inflammatory arthritis in adults. Recent studies have found that elevated uric acid levels are related to the occurrence of dementia. We conducted a study to investigate the association between dementia and gout or hyperuricaemia.

DESIGN

Systematic review and meta-analysis of cohort studies.

DATA SOURCES

Studies were screened from inception to 28 June 2019 by searching Medline, Embase and the Cochrane Library databases.

ELIGIBILITY CRITERIA

Cohort studies comparing the risk of dementia in patients with gout and hyperuricaemia versus non-gout and non-hyperuricaemia controls were enrolled.

DATA EXTRACTION AND ANALYSIS

Two reviewers separately selected studies and extracted data using the Medical Subject Headings without restriction on languages or countries. The adjusted HRs were pooled using the DerSimonian and Laird random effects model. Sensitivity analyses were conducted to evaluate the stability of the results. Publication bias was evaluated using Egger's and Begg's tests. Quality assessment was performed according to the Newcastle-Ottawa Scale.

RESULTS

Four cohort studies that met the inclusion criteria were included in our meta-analysis. We found that gout and hyperuricaemia did not increase the risk of dementia, with a pooled HR of 0.94 (95% CI 0.69 to 1.28), but might decrease the risk of Alzheimer's disease (AD), with a pooled HR of 0.78 (95% CI 0.64 to 0.95). There was little evidence of publication bias. Quality assessment of the included studies was high (range: 6-8 points).

CONCLUSIONS

Our study shows that gout and hyperuricaemia do not increase the risk of dementia. However, gout and hyperuricaemia might have a protective effect against AD. Due to the limited number of research articles, more investigations are needed to demonstrate the potential relationship between dementia and gout or hyperuricaemia.

Gout

Gout is a common and treatable disease caused by the deposition of monosodium urate crystals in articular and non-articular structures. Increased concentration of serum urate (hyperuricaemia) is the most important risk factor for the development of gout. Serum urate is regulated by urate transporters in the kidney and gut, particularly GLUT9 (SLC2A9), URAT1 (SLC22A12), and ABCG2. Activation of the NLRP3 inflammasome by monosodium urate crystals with release of IL-1β plays a major role in the initiation of the gout flare; aggregated neutrophil extracellular traps are important in the resolution phase. Although presenting as an intermittent flaring condition, gout is a chronic disease. Long-term urate lowering therapy (eg, allopurinol) leads to the dissolution of monosodium urate crystals, ultimately resulting in the prevention of gout flares and tophi and in improved quality of life. Strategies such as nurse-led care are effective in delivering high-quality gout care and lead to major improvements in patient outcomes.

Association between Anti-inflammatory Drug and Dementia in Patients with Gout: A Nationwide, Population-Based Nested Case-Control Study

Introduction: The interaction between hyperuricemia and the cognitive system is still under debate, with studies presenting somewhat conflicting results. Objectives: This study aimed to investigate the risk of dementia in patients with gout who are administered anti-inflammatory drug treatment. Methods: Gouty arthritis patients aged 50 years and older, who received at least one of the background therapy drugs (colchicine, corticosteroids, or nonsteroidal anti-inflammatory drugs for 6 months), were divided into the following groups and compared: patients who had dementia over a period of 5 years (n = 2,292) and matched patients without dementia (n = 2,292). Results: We found that the most significant risk factors for dementia were stroke (OR, 2.66; 95% C.I., 2.33-3.03; AOR, 2.39; 95% C.I., 2.08-2.75) and depression (OR, 3.72; 95% C.I., 3.01-4.6; AOR, 3.25; 95% C.I., 2.60-4.05). The results of anti-gout drug administration, which impacted the dementia risk among patients of all ages (but especially in 50-64-year-old patients), demonstrated a higher risk ratio after 90 days of corticosteroid use (OR, 3.39; 95% C.I., 1.15-9.99), which was further increased after 180 days (OR, 3.61; 95% C.I., 1.31-9.94). We revealed that female patients experienced a significant increase in dementia risk after 90 days of corticosteroid administration, whereas male patients experienced a significant increase only after 180 days (OR, 1.52; 95% C.I., 1.06-2.17). Conclusion: We had identified that > 90-day corticosteroid administration is a significant dementia risk factor in both female and male patients of all ages, especially in the 50-60-year-old group.

Association Between Gamma-Glutamyl Transferase and Mild Cognitive Impairment in Chinese Women

Background: Dementia, as a global public health problem, is becoming increasingly serious. As a precursor of dementia, mild cognitive impairment (MCI) plays an important role in the diagnosis and prevention of dementia. Recent studies have found a correlation between gamma-glutamyl transferase (GGT) levels and cognitive function in men. The relationship between GGT levels and cognitive function in women remains unclear because GGT activity and expression differ between the sexes. Method: We recruited a total of 2,943 Chinese women from Jidong and Taian in 2019. We grouped the participants according to GGT levels, diagnosed MCI using the Montreal Cognitive Assessment (MOCA) scale, and modeled the study outcomes using logistic regression to explore the relationship between GGT level and MCI. We also analyzed the interaction of obesity, sleep duration, and hyperuricemia with GGT in the development of MCI. Results: The prevalence of MCI increased with increasing GGT level, from the lowest quartile to the highest quartile of GGT: 8.4% (66/786), 14.2% (119/840), 17.6% (108/613), and 21.4% (151/704), respectively. At the same time, as GGT levels increased, so did the risk of MCI. In the fully adjusted model, compared with those for participants in the lowest GGT quartiles, the odds ratios (ORs), and 95% confidence intervals (CIs) for MCI for participants in the second, third, and fourth GGT quartiles were 1.49 (1.04-2.12), 1.53(1.06-2.21), and 1.88 (1.33-2.65), respectively. The risk of developing MCI was further increased in people with high GGT levels who were obese (OR = 1.96, 95% CI: 1.39-2.76, P < 0.001), slept less (OR = 1.91, 95% CI: 1.35-2.71, P < 0.001), had high levels of uric acid (OR = 1.55, 95% CI: 1.03-2.32, P < 0.001), or after menopause (OR = 2.92, 95% CI: 2.07-4.12, P < 0.001). Conclusion: We found that MCI is more common in women with elevated GGT levels, so GGT could be a potential diagnostic marker for MCI. Meanwhile, our findings indicated that women with high GGT levels had an increased risk of MCI when they were obese, sleep deprived, had high serum uric acid (SUA) levels or underwent menopause.

Association Between Use of Anti-gout Preparations and Dementia: Nested Case-Control Nationwide Population-Based Cohort Study

Objectives: Gout is the most common form of inflammatory arthritis and was found to be independently associated with incident dementia in the elderly. However, the associations between anti-gout preparations and dementia were not well-studied.

Methods: Data were collected from Taiwan's National Health Insurance Research Database (NHIRD). A 2005–2013 retrospective cohort study was conducted, and all investigated subjects were identified by International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Clinical Modification. Conditional logistic regression was used to evaluate the odds ratio of dementia in relation to different gout preparations (benzbromarone, allopurinol, sulfinpyrazone, probenecid) and number of days of anti-gout preparation use, after adjustment for potential confounding variables.

Results: A total of 3,242 gout patients with and without dementia were selected from the NHIRD and included in the final analysis after 1:1 matching for age, gender, and diagnosis year of gout. In the anti-gout preparations, only use of Benzbromarone decreased the risk of dementia (adjusted OR, 0.81; 95% CI, 0.68–0.97). The result of the subgroup analysis revealed a trend toward a lower risk of dementia with longer use of benzbromarone. Use of benzbromarone for ≥180 days showed a significantly lower risk of dementia (adjusted OR, 0.72; 95% CI, 0.58–0.89). Moreover, the protective effect was more pronounced in males compared with females.

Conclusion: This cohort study reveals that gout patients taking benzbromarone are at a decreased risk of developing incident dementia, especially with longer use and in male. Further prospective trials are warranted to confirm our findings.

Inosine 5'-Monophosphate to Raise Serum Uric Acid Level in Multiple System Atrophy (IMPROVE-MSA study)

The aim of this trial was to investigate the safety, tolerability, and capability of serum uric acid (UA) elevation of inosine 5'-monophosphate (IMP) in multiple system atrophy (MSA). The IMPROVE-MSA trial was a randomized, double-blind, placebo-controlled trial in patients with MSA with no history of hyperuricemia-related disorders. The participants were assigned to placebo (n = 25) or IMP (n = 30) in a 1 to 1 ratio, and then followed up for 24 weeks. The primary end points included safety, tolerability, and alteration of the serum UA level during the follow-up period. The secondary end points were changes in scores of the unified MSA rating scale (UMSARS) and the Mini-Mental Status Examination (MMSE) and Montreal Cognitive Assessment (MoCA). The total number of adverse events (AEs) and serious AEs was comparable between the active and placebo groups. Serum UA level (mg/dL) was significantly increased from baseline (active vs. placebo, 4.57 vs. 4.58; P = 0.98) to study end point (6.96 vs. 4.43; P < 0.001) in the active group compared with the placebo group (time × group interaction; P < 0.001). The change in UMSARS scores did not differ between the active and placebo groups. However, the active group showed better alterations in MoCA scores with nominal significance (P < 0.001) and tendency for better alterations in MMSE scores (P = 0.09) than the placebo group. Our data demonstrated that IMP treatment was generally safe and well-tolerated in patients with MSA. A further trial with a long-term follow-up is required to examine whether UA elevation will slow clinical progression in early MSA.

Review of the Protective Effects of Statins on Cognition

Elevated cholesterol is a major risk factor in the development of cardiovascular disease. Statins have proven to be effective in lowering low-density lipoprotein cholesterol as well as the incidence of cardiovascular events. As a result, statins are widely prescribed in the United States, with an estimated 35 million patients on statins. Many of these patients are older than age 65 and suffer from various comorbidities, including mild to severe cognitive impairment. Early studies looking at the effects of statins on cognition have shown that statin use may lead to mild reversible cognitive decline, although long-term studies have shown inconclusive findings. In recent years, studies have shown that the use of statins in certain groups of patients may lead to a reduction in the rate of cognitive decline. One hypothesis for this finding is that statin use can reduce the risk of cerebrovascular disease which may, in turn, reduce the risk of mild cognitive decline and dementia. With numerous patients currently prescribed statins and the likelihood that more patients will be prescribed the medication in the coming years, it is important to review the current literature to determine the association between statin use and cognitive decline, as well as determine how statins may be beneficial in preventing cognitive decline.

Debates in gout management

PURPOSE OF REVIEW

This review discusses the findings of recently published translational research studies that have the potential to directly impact on the management of gout patients.

RECENT FINDINGS

Recent research suggests that treat-to-target urate-lowering treatment (ULT) alongside individualized education about gout, and shared decision making results in excellent adherence with ULT and prevents gout flares in the long term. Such interventions should preferentially be delivered face-to-face rather than remotely. The recently published CARES study raises the possibility that febuxostat increases the risk of death in people with preexisting major cardiovascular diseases, and, allopurinol should remain the first-choice ULT. There is paucity of data on the dosing of ULT for managing hyperuricaemia in gout patients with chronic kidney disease. However, recent research suggests that the dose of allopurinol can be gradually increased to above the conventional renal dose in people with chronic kidney disease without allopurinol hypersensitivity syndrome. However, additional larger studies are needed in this field.

SUMMARY

In summary, long-term treat-to-target ULT prevents gout flares and improves quality of life. Given the recent safety concerns, gradually up-titrated allopurinol remains the first-line urate-lowering drug.

Ankylosing spondylitis is associated with an increased risk of dementia: A systematic review and meta-analysis

OBJECTIVES

To investigate the relationship between ankylosing spondylitis (AS) and risk of dementia.

METHODS

Potentially eligible studies that compared the risk of developing dementia between patients with AS and individuals without AS were identified from MEDLINE and EMBASE databases from inception to May 2019 using a search strategy that comprised terms for "dementia" and "ankylosing spondylitis". Eligible studies could be either cohort studies or case-control studies. For cohort design, eligible studies included patients with AS and comparators without AS and followed them for incident dementia. For case-control design, eligible studies included cases with dementia and controls without dementia and explored prior history of AS in both groups. Effect estimate and standard error from each study were extracted and combined together using the random effect, generic inverse variance. Funnel plot was used to assess for publication bias.

RESULTS

A total of 7091 articles were identified using the aforementioned search strategy. After 2 rounds of independent review by 3 investigators, 4 studies fulfilled the inclusion criteria and were included into the meta-analysis. The risk of developing dementia was significantly higher among patients with AS than individuals without AS with the pooled relative risk of 1.19 (95% CI 1.01-1.41; I²  = 76%). The funnel plot was relatively symmetric and was not suggestive of presence of publication bias.

CONCLUSION

A significantly 1.2 fold higher risk of developing dementia among patients with AS was demonstrated by this systematic review and meta-analysis.

Gout and the risk of epilepsy: A population-based cohort study

Gout is a chronic disease related to uric acid metabolism. It involves crystals of uric acid accumulating in the joints, causing joint pain and releasing cytokines that trigger inflammation. Inflammation is a key component in the pathogenesis of epilepsy. Thus, we conducted a cohort study to investigate if epilepsy is associated with gout and determine the risk of epilepsy in patients with gout.The gout cohort was obtained from the Registry of Catastrophic Illnesses Patient Database (RCIPD). We identified 104,238 patients who were aged 20 years or more and newly diagnosed with gout between 2000 and 2011 and 3 outpatient visits or history of gout-specific hospitalization between 2000 and 2011. Patients without gout were frequency matched with the gout cohort at a 2:1 ratio according to age, sex, comorbidities, and year of gout diagnosis.The gout cohort showed a 1.27-fold higher overall crude hazard ratio (HR) for epilepsy compared with the control cohort. After we adjusted the analyses by age, sex, and comorbidities the gout patients displayed an increased risk of epilepsy compared with the control group (adjusted HR = 1.25, 95% confidence interval = 1.15-1.36).This study revealed a significantly higher risk of epilepsy in patients with gout. It provides further evidence for the debate around the effect of gout on brain health.