Sleep Apnea and the Risk of Incident Gout: A Population-Based, Body Mass Index-Matched Cohort Study

Impact of gout on cardiovascular disease mortality: a meta-analysis

BACKGROUND

Several epidemiological studies have suggested that gout patients have a higher risk of cardiovascular disease mortality than healthy people. In contrast, the association between gout and cardiovascular disease (CVD) mortality was not obvious in other studies. In the present study, we aimed to investigate the relative risk for CVD mortality in gout patients in comparison to healthy controls.

METHODS

Literature published before March 2023 was searched in Google Scholar, PubMed, and the Web of Science. We summarized the impact of gout on CVD mortality with a meta-analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) regarding the impact of gout on CVD mortality were summarized with STATA 12.0 software.

RESULTS

Compared to individuals without gout, those with gout had higher mortality risks for CVD during follow-up, with a random effects model showing a risk of 1.30 (95% CI 1.15 to 1.48, p < 0.001; p-value for Cochran Q test < 0.001, I2 = 95.9%). Similarly, subjects with gout had a mortality risk of 1.28 (95% CI 1.12 to 1.46, p < 0.001; p-value for Cochran Q test = 0.050, I2 = 50.2%) for coronary heart disease (CHD) mortality during follow-up using the same statistical model. Furthermore, using a fixed effects model, individuals with gout had a mortality risk of 1.13 (95% CI 1.00 to 1.27, p = 0.049; p-value for Cochran Q test = 0.494, I2 = 0.0%) for myocardial infarction (MI) mortality during follow-up.

CONCLUSION

In conclusion, this meta-analysis provides evidence supporting a markedly increased mortality risk from CVD and CHD as well as MI in patients with gout relative to reference subjects without gout.

Gout Flares and Mortality After Sodium-Glucose Cotransporter-2 Inhibitor Treatment for Gout and Type 2 Diabetes

Importance

Recurrent flares are the hallmark of clinical manifestation of gout. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been associated with a lower risk of incident gout; however, their association with recurrent flares is unknown.

Objective

To examine the association of SGLT2i vs active comparators (ie, glucagonlike peptide-1 receptor agonists [GLP-1 RA] or dipeptidyl peptidase-4 inhibitors [DPP-4i]) with the risk of recurrent gout flares and all-cause mortality among patients with gout and type 2 diabetes.

Design, Setting, and Participants

This population-based retrospective cohort study was performed from January 1, 2013, to March 31, 2022, using a UK primary care database. Participants included patients with gout and type 2 diabetes with visits to their general practitioners.

Exposures

Initiation of treatment with SGLT2i or active comparators.

Main Outcomes and Measures

The primary outcome was the number of recurrent gout flares ascertained using recorded codes and prescription records. Secondary outcomes were the first recurrent gout flare and all-cause mortality. The association of SGLT2i compared with active comparators for the risk of recurrent flares, the first recurrent flare, and all-cause mortality was assessed using Poisson regression or the Cox proportional hazards model with propensity score overlap weighting.

Results

Of a total of 5931 patients included in the analysis (mean [SD] age, 66.0 [11.6] years; 4604 [77.6%] men), 1548 initiated SGLT2i treatment and 4383 initiated treatment with active comparators during the study period. The relative rate of the recurrent flares with SGLT2i vs active comparators was 0.79 (95% CI, 0.65-0.97). Similar results were observed in the association of SGLT2i with the rate of recurrent flares when compared with DPP-4i or GLP-1 RA. For the first recurrent flare for SGLT2i vs active comparators, rate difference was -8.8 (95% CI, -17.2 to -0.4) per 1000 person-years and the hazard ratio was 0.81 (95% CI, 0.65-0.98). All-cause mortality per 1000 person-years was 18.8 for SGLT2i and 24.9 for active comparators, with rate difference of -6.1 (95% CI, -10.6 to -1.6) per 1000 person-years and hazard ratio of 0.71 (95% CI, 0.52-0.97).

Conclusions and Relevance

The findings of this cohort study suggest that SGLT2i were associated with a lower risk of recurrent gout flares and mortality than their active comparators in patients with gout and type 2 diabetes. These findings further suggest that SGLT2i could help reduce the burden of recurrent gout flares and could also narrow the mortality gap between patients with gout and the general population.

Association between obstructive sleep apnea symptoms and gout in US population, a cross-sectional study

The results of association between Obstructive Sleep Apnea (OSA) and gout are not consistent. Participants aged 20 years or older in the National Health and Nutrition Examination Survey (NHANES) 2007-2008 and 2015-2018 were included. Weighted univariable and multivariable logistic regressions were used to evaluate the association between OSA symptoms and gout. The subgroup and sensitivity analyses were also performed. Among the 15,947 participants in this study, the mean age was 47.8 years old, 48.87% of whom were male, 4891 had OSA symptoms, and 842 had gout. In multivariable logistic regression analyses, OSA symptoms were positively associated with gout in all models. The odds ratio (OR) was 1.315 and 95% confidence interval (CI) was 1.070-1.616 in fully adjusted model 4. In the subgroup analyses, we found a considerable interaction between OSA symptoms and gender with gout (P for interaction = 0.003). In the sensitivity analyses, the association between OSA symptoms and gout remained stable after adjustment for congestive heart failure and diuretics using. OSA symptoms were associated with an increased likelihood of gout. This association could especially be found in female participants.

The Risk of BPPV, Meniere's Disease, and Vestibular Neuronitis in Patients with Gout: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study evaluated the impact of pre-existing gout on the occurrence of benign paroxysmal positional vertigo (BPPV), Meniere’s disease, and vestibular neuronitis, with the goal of identifying novel associations of gout with other comorbid diseases. The 2002−2019 Korean National Health Insurance Service Health Screening Cohort data were retrospectively analyzed. 23,827 patients with gout were matched to 95,268 controls without gout for age, sex, income, region of residence, and index date. The occurrence of BPPV, Meniere’s disease, and vestibular neuronitis was evaluated in both groups. The hazard ratios (HRs) of gout for BPPV, Meniere’s disease, and vestibular neuronitis were calculated using a stratified Cox proportional hazard model. Participants with gout demonstrated a 1.13-fold higher risk of BPPV (95% CI, 1.06−1.21, p < 0.001) and a 1.15-fold higher risk of Meniere’s disease (95% CI, 1.15−1.37, p < 0.001) than the matched control group. However, the HR for vestibular neuronitis was not significantly higher in the gout group (adjusted HR = 1.06, 95% CI, 0.93−1.21, p = 0.391). A previous history of gout was related to a higher risk of BPPV and Meniere’s disease. Additional studies are necessary to elucidate the mechanism underlying the relationship between gout and comorbid diseases such as BPPV and Meniere’s disease.

Linear and non-linear Mendelian randomization analyses of sex-specific associations between sleep duration and hyperuricemia

Background

Observational studies have suggested a potential non-linear association between sleep duration and hyperuricemia. However, the causal nature and sex-specific differences are poorly understood. We aimed to determine the shape of sex-specific causal associations between sleep duration and hyperuricemia in the UK Biobank.

Methods

Logistic regression was used to investigate the observational association between self-reported sleep duration and hyperuricemia among 387,980 white British participants (mean age: 56.9 years and 46.0% males). Linear and non-linear Mendelian Randomization (MR) analyses were performed to assess the causal association between continuous sleep duration and hyperuricemia. The causal effects of genetically predicted short (<7 h) and long (>8 h) sleep durations on hyperuricemia were further estimated, respectively.

Results

Traditional observational analysis suggested U- and J-shaped associations between sleep duration and hyperuricemia in females and males, respectively. Linear MR did not support the causal effect of sleep duration on hyperuricemia. Non-linear MR demonstrated an approximately U-shaped causal association between continuous sleep duration and hyperuricemia in overall participants and females, but not in males. Genetically predicted short sleep duration was significantly associated with hyperuricemia in females (OR [95% CI]: 1.21 [1.08–1.36]; P = 0.001), but not in males (1.08 [0.98–1.18]; P = 0.137). By contrast, genetically predicted long sleep duration was not significantly associated with the risk of hyperuricemia in either females or males.

Conclusion

Genetically predicted short sleep duration is a potential causal risk factor for hyperuricemia for females but has little effect on males. Long sleep duration does not appear to be causally associated with hyperuricemia.

Risk of gout flares after COVID-19 vaccination: A case-crossover study

OBJECTIVE

Routine vaccinations are associated with an increased risk of gout flares. We examined the association between COVID-19 vaccination, an immunization program implemented to a large proportion of population, and the risk of gout flares.

METHODS

We conducted a time-stratified case-crossover study among patients with gout who experienced gout flares between December 2020 and September 2021, using data from The Health Improvement Network. We compared the risk of gout flares on each of the seven days on and after the day of COVID-19 vaccination vs. no vaccination during that period using conditional logistic regression. In addition, we performed subgroup analyses stratified by different COVID-19 vaccines (i.e., BNT162b2, hereafter referred to as BNT, and ChAdOx1 nCov-19, hereafter referred to as ChAd).

RESULTS

Among 5,904 patients with gout (mean age: 63·1 years; 85·5% male) who experienced gout flares within one month, the risk of gout flares slightly increased on the second day after COVID-19 vaccination (odds ratio: 1·44; 95% CI: 1·02 to 2·07). The risk of gout flares also slightly increased after receiving COVID-19 vaccine on other remaining days (ORs ranged from 1·03 to 1·22); however, none of them was statistically significant. An increased risk of gout flares on the second day after vaccination was mainly observed for the ChAd vaccine (odds ratio: 1·44; 95% CI: 1·00 to 2·05), but not for BNT vaccine (odds ratio: 1·18; 95% CI: 0·67 to 2·02).

CONCLUSION

COVID-19 vaccination, mainly ChAd vaccination, slightly increases the risk of gout flares on the second day after vaccination. This finding reassures the safety of COVID-19 vaccination for patients with gout.

Assessing the causal associations of obstructive sleep apnea with serum uric acid levels and gout: a bidirectional two-sample Mendelian randomization study

OBJECTIVE

Multiple observational studies have reported the close associations of obstructive sleep apnea (OSA) with serum uric acid (SUA) levels and gout. However, the causal nature and direction remains unclear.

METHODS

A bidirectional two-sample Mendelian randomization (MR) study was performed, based on publicly available genome-wide association studies (GWAS) summary statistics, to investigate whether OSA is causally related to SUA levels, gout and vice versa. The inverse-variance weighted (IVW) was used as the primary analysis approach, supplemented with four sensitive analysis methods applied to assess the robustness of the results. Moreover, multivariable MR (MVMR) was utilized to evaluate the independent causal effect of OSA on SUA and gout after adjusting for body mass index (BMI), hypertension, type 2 diabetes (T2D), coronary artery disease (CAD), and chronic kidney disease (CKD).

RESULTS

Genetically predicted OSA liability was significantly associated with increased levels of SUA (IVW method: β = 0.19, 95% CI = 0.11 - 0.26, P = 7.24 × 10^-7) and risk of gout [IVW method: odds ratio (OR) = 1.75 95% CI = 1.13 - 2.69, P = 0.01] in univariable MR. The MVMR results suggested that OSA retained its significant association with increased SUA levels, whereas the significant association between OSA and gout was attenuated to null after adjusting for BMI and T2D. No causal effect of OSA on SUA levels and gout was found in the reverse direction.

CONCLUSIONS

Our findings suggest that OSA was causally associated with increased levels of SUA, but was not independently associated with gout risk.

Snoring and napping independently increased the serum uric acid levels and hyperuricemia risk: The Henan Rural Cohort Study

BACKGROUND AND AIMS

Evidence on the association of snoring, daily sleep duration (daytime napping and night sleep duration) with hyperuricemia (HUA) was limited, especially in the resources-poor areas. This study aimed to investigate the independent effect of snoring frequency and daily sleep duration on HUA prevalence in rural Chinese adults.

METHODS AND RESULTS

29,643 participants aged 18-79 years were included in the final cross-sectional analysis from the Henan Rural Cohort Study. Multivariate logistic regression and linear regression models with HUA and serum uric acid (SUA) levels as dependent variables were conducted, respectively. Of the 29,643 included adults, 3498 suffered from HUA. Compared to never snoring, the adjusted odds ratio (OR) and 95% confidence interval (CI) of HUA for rare snoring, occasional snoring, and habitual snoring were 1.35 (1.17, 1.56), 1.30 (1.14, 1.47), and 1.59 (1.47, 1.73), respectively (P for trend <0.001). Compared with no napping, participants who had daytime napping of 61-90 and > 91 min were associated with a 29% and 30% increase in the prevalence of HUA, respectively (P for trend <0.001). But in night sleep duration groups, no significant associations were observed. The positive associations between snoring and HUA were attenuated in people aged ≥65 and people with type 2 diabetes mellitus (both P for interaction <0.05).

CONCLUSION

Habitual snoring or longer daytime napping was independently associated with increased HUA prevalence and SUA levels in rural Chinese adults, which indicates the significance of early intervention and treatment of snoring and longer daytime napping to prevent hyperuricemia.

Allopurinol Initiation and All-Cause Mortality Among Patients With Gout and Concurrent Chronic Kidney Disease : A Population-Based Cohort Study

BACKGROUND

Two recent randomized clinical trials of escalating doses of allopurinol for the progression of chronic kidney disease (CKD) reported no benefits but potentially increased risk for death. Whether the risk could occur in patients with gout and concurrent CKD remains unknown.

OBJECTIVE

To examine the relation of allopurinol initiation, allopurinol dose escalation, and achieving target serum urate (SU) level after allopurinol initiation to all-cause mortality in patients with both gout and CKD.

DESIGN

Cohort study.

SETTING

The Health Improvement Network U.K. primary care database (2000 to 2019).

PARTICIPANTS

Patients aged 40 years or older who had gout and concurrent moderate-to-severe CKD.

MEASUREMENTS

The association between allopurinol initiation and all-cause mortality over 5-year follow-up in propensity score (PS)-matched cohorts was examined. Analysis of hypothetical trials were emulated: achieving target SU level (<0.36 mmol/L) versus not achieving target SU level and dose escalation versus no dose escalation for mortality over 5-year follow-up in allopurinol initiators.

RESULTS

Mortality was 4.9 and 5.8 per 100 person-years in 5277 allopurinol initiators and 5277 PS-matched noninitiators, respectively (hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.93]). In the target trial emulation analysis, the HR of mortality for the achieving target SU level group compared with the not achieving target SU level group was 0.87 (CI, 0.75 to 1.01); the HR of mortality for allopurinol in the dose escalation group versus the no dose escalation group was 0.88 (CI, 0.73 to 1.07).

LIMITATION

Residual confounding cannot be ruled out.

CONCLUSION

In this population-based data, neither allopurinol initiation, nor achieving target SU level with allopurinol, nor allopurinol dose escalation was associated with increased mortality in patients with gout and concurrent CKD.

PRIMARY FUNDING SOURCE

Project Program of National Clinical Research Center for Geriatric Disorders.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Sleep disorders and gout in Australian adults

BACKGROUND

The aims of our study were two-fold. Firstly, to determine if there is an association between gout and OSA in a representative Australian adult population. Secondly, to explore associations between gout and patient reported sleep outcomes.

METHODS

A cross-sectional national online survey of a representative sample of Australian adults > 18 years assessed self-reported doctor-diagnosed OSA, insomnia and patient reported sleep outcomes. Possible undiagnosed OSA was estimated using self-reported frequent loud snoring and witnessed apnoeas. Participants self-reported physician-diagnosed gout and other health conditions. Multivariable logistic regression analyses were performed for both objectives. Odds ratios with 95% confidence intervals were reported.

RESULTS

There were 1948 participants of whom 126 (6.5%) had gout and 124 (6.4%) had diagnosed sleep apnoea. After adjusting for age, body mass index (BMI), sex, alcohol intake and the presence of arthritis, those with obstructive sleep apnoea diagnosed on polysomnography were twice as likely to report having gout compared to those without. (OR = 2.6, 95% CI 1.5-4.6). Additionally, participants with symptoms suggestive of sleep apnoea were also twice as likely to have gout compared to those without (OR = 2.8, 95%CI 1.6-5.1). There was also a higher likelihood of restless legs syndrome, insomnia and worry about sleep in patients with gout.

CONCLUSION

Diagnosed and suspected OSA are associated with higher likelihood of gout. Participants with gout are also more likely to report suffering from restless legs syndrome, insomnia and worry about their sleep. Given the morbidity associated with sleep problems, we should be vigilant regarding sleep health in our patients with gout.

Hypouricemia and Mortality Risk in the US General Population

OBJECTIVE

The most recent European Alliance of Associations for Rheumatology (EULAR) recommendations for gout advise against maintaining a serum urate (SU) level of <3 mg/dl for prolonged periods of time. While several Asian cohort studies have shown higher rates of mortality in individuals with extremely low SU levels, data from non-Asian cohort studies are scarce, and the relationship between hypouricemia, cardiovascular risk, and mortality remains unclear.

METHODS

Using data collected from the 1988-1994 and 1999-2008 National Health and Nutrition Examination Survey (NHANES), we examined the relationship between SU level and overall and cause-specific mortality in 41,807 adults in the US. We calculated multivariable hazard ratios (HRs) that were compared to a referent SU level of 5-6 mg/dl for SU categories <4, 4-5, 6-7, 7-8, and >8 mg/dl in men and SU categories <3, 3-4, 4-5, 6-7, and >7 mg/dl in women.

RESULTS

A higher mortality risk was not observed in women who had an SU level of <3 mg/dl (HR 1.09 [95% confidence interval (95% CI) 0.92-1.28]). A 28% higher mortality risk was observed in men who had an SU level of <4 mg/dl (HR 1.28 [95% CI 1.13-1.45]), with a nearly three-times higher mortality risk from diabetes mellitus also noted (HR 2.89 [95% CI 1.59-5.23]), but no increase in mortality from any other specific cause.

CONCLUSION

We found no long-term excess mortality risk among American women with SU levels as low as <3 mg/dl, a finding which is incompatible with the notion of a causal relationship between hypouricemia and premature mortality in women. We found excess all-cause mortality and diabetes mellitus-related mortality among hypouricemic American men, which may in part be attributable to the uricosuric effect of hyperglycemia in fatal uncontrolled diabetes mellitus (analogous to reverse causality).

SLEEP APNEA IN GOUT PATIENTS: UNDERLYING MECHANISMS AND SHARED PATIENT SUBTYPES

Acute and chronic inflammation in gout causes permanent tissue damage, leads to restricted mobility and significantly reduces the quality of life. Obstructive sleep apnea (OSA) is a breath disordered sleep disease, which is a risk factor for respiratory, cardiovascular and cerebrovascular complications, nephropathy and other diseases. The aim of this paper was to explore the underlying mechanisms and shared pathways, targets and biomarkers of sleep apnea and gout. aiming at providing clear evidence about whether OSAS patients have higher serum uric acid levels and more susceptible to gout. Materials and methods. We conducted this literature analysis on relevant studies, which were identified via electronic databases from inception to May 30, 2020. Study selection was conducted according to predesigned criteria, and two authors independently extracted data from included studies. Results. In the period from 2010 to 2020, 4 large-scale population-based studies were conducted to prove that OSA can affect the level of uric acid, resulting in increased incidence of gout in OSA patients. Only one big population-based study during 2010-2020 assessed the development of OSA against the background of gout. The data from these studies showed an undoubted relationship between the two diseases, but to date it is not completely known how much it is due to common risk factors and how interlinked the development mechanisms are. Conclusions. Relationship between OSA, gout, and pro-inflammatory/metabolic disorders is therefore complex; with some recent studies indicate different mechanisms may play a role in the development of OSA-gout combination. The inconsistency in results may indicate the presence of several patient profiles or subtypes with gout-OSA comorbidity: combined with metabolic syndrome (most common), combined with renal dysfunction without obesity, and others (dietary violations, genetic diseases, acidosis). This paper reviews the research progress on the relationship between the epidemiological characteristics of OSA and the incidence of gout, with the insight into pathogenetic mechanisms of comorbidity.

Obstructive Sleep Apnea, a Risk Factor for Cardiovascular and Microvascular Disease in Patients With Type 2 Diabetes: Findings From a Population-Based Cohort Study

OBJECTIVE

To determine the risk of cardiovascular disease (CVD), microvascular complications, and mortality in patients with type 2 diabetes who subsequently develop obstructive sleep apnea (OSA) compared with patients with type 2 diabetes without a diagnosis of OSA.

RESEARCH DESIGN AND METHODS

This age-, sex-, BMI-, and diabetes duration-matched cohort study used data from a U.K. primary care database from 1 January 2005 to 17 January 2018. Participants aged ≥16 years with type 2 diabetes were included. Exposed participants were those who developed OSA after their diabetes diagnosis; unexposed participants were those without diagnosed OSA. Outcomes were composite CVD (ischemic heart disease [IHD], stroke/transient ischemic attack [TIA], heart failure [HF]), peripheral vascular disease (PVD), atrial fibrillation (AF), peripheral neuropathy (PN), diabetes-related foot disease (DFD), referable retinopathy, chronic kidney disease (CKD), and all-cause mortality. The same outcomes were explored in patients with preexisting OSA before a diagnosis of type 2 diabetes versus diabetes without diagnosed OSA.

RESULTS

A total of 3,667 exposed participants and 10,450 matched control participants were included. Adjusted hazard ratios for the outcomes were as follows: composite CVD 1.54 (95% CI 1.32, 1.79), IHD 1.55 (1.26, 1.90), HF 1.67 (1.35, 2.06), stroke/TIA 1.57 (1.27, 1.94), PVD 1.10 (0.91, 1.32), AF 1.53 (1.28, 1.83), PN 1.32 (1.14, 1.51), DFD 1.42 (1.16, 1.74), referable retinopathy 0.99 (0.82, 1.21), CKD (stage 3-5) 1.18 (1.02, 1.36), albuminuria 1.11 (1.01, 1.22), and all-cause mortality 1.24 (1.10, 1.40). In the prevalent OSA cohort, the results were similar, but some associations were not observed.

CONCLUSIONS

Patients with type 2 diabetes who develop OSA are at increased risk of CVD, AF, PN, DFD, CKD, and all-cause mortality compared with patients without diagnosed OSA. Patients with type 2 diabetes who develop OSA are a high-risk population, and strategies to detect OSA and prevent cardiovascular and microvascular complications should be implemented.

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

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

Obstructive sleep apnea and the risk of gout: a population-based case-control study

Background

Patients with obstructive sleep apnea (OSA) might be at risk of gout because of pathophysiological mechanisms that can lead to hyperuricemia and eventually gout or because of shared risk factors between both diseases. The objective of the present study was to investigate the risk of gout in patients with OSA.

Methods

A population-based case-control study using the UK Clinical Practice Research Datalink GOLD including all patients aged 40 years and older with a first diagnosis of gout between 1987 and 2014. Gout cases were matched by year of birth, sex, and practice to non-gout controls. Conditional logistic regression estimated the risk of gout with an earlier diagnosis of OSA. Analyses were adjusted for lifestyle factors, comorbidities, and recent drug use.

Results

One hundred eleven thousand five hundred nine cases were matched with 210,241 controls. Patients with OSA were at increased risk of gout (OR 1.86; 95%CI (1.71–2.02). However, this association disappeared (OR 1.05; 95% CI 0.96–1.16) after adjustment for smoking status, body mass index (BMI), alcohol use, a history of heart failure, diabetes mellitus, renal function, and recent use of diuretics and other medications. Among females with OSA and patients with OSA associated with heart failure, renal impairment, or higher BMI, the risk of gout was however still increased when compared to the total control population.

Conclusion

This study showed that the observed association between OSA and gout disappeared after adjustment.

Toxicogenomic analysis of publicly available transcriptomic data can predict food, drugs, and chemical-induced asthma

Background

: With the increasing incidence of asthma, more attention is focused on the diverse and complex nutritional and environmental triggers of asthma exacerbations. Currently, there are no established risk assessment tools to evaluate asthma triggering potentials of most of the nutritional and environmental triggers encountered by asthmatic patients.

Purpose

 The objective of this study is to devise a reliable workflow, capable of estimating the toxicogenomic effect of such factors on key player genes in asthma pathogenesis.

Methods

Gene expression extracted from publicly available datasets of asthmatic bronchial epithelium were subjected to a comprehensive analysis of differential gene expression to identify significant genes involved in asthma development and progression. The identified genes were subjected to Gene Set Enrichment Analysis using a total of 31,826 gene sets related to chemical, toxins, and drugs to identify common agents that share similar asthma-related targets genes and signaling pathways.

Results

Our analysis identified 225 differentially expressed genes between severe asthmatic and healthy bronchial epithelium. Gene Set Enrichment Analysis of the identified genes showed that they are involved in response to toxic substances and organic cyclic compounds and are targeted by 41 specific diets, plants products, and plants related toxins (eg adenine, arachidonic acid, baicalein, caffeic acid, corilagin, curcumin, ellagic acid, luteolin, microcystin-RR, phytoestrogens, protoporphyrin IX, purpurogallin, rottlerin, and salazinic acid). Moreover, the identified chemicals share interesting inflammation-related pathways like NF-κB.

Conclusion

Our analysis was able to explain and predict the toxicity in terms of stimulating the differentially expressed genes between severe asthmatic and healthy epithelium. Such an approach can pave the way to generate a cost-effective and reliable source for asthma-specific toxigenic reports thus allowing the asthmatic patients, physicians, and medical researchers to be aware of the potential triggering factors with fatal consequences.

Crystal-proven gout patients have an increased mortality due to cardiovascular diseases, cancer, and infectious diseases especially when having tophi and/or high serum uric acid levels: a prospective cohort study

OBJECTIVE

To investigate the cause-specific mortality and the possible involved clinical characteristics with increased mortality in a cohort of 700 patients with crystal-proven gout. The cause-specific mortality of gout was compared to the mortality of the general population.

METHODS

Patients with arthritis referred for diagnosis were consecutively included in the Gout Arnhem-Liemers Cohort (GOAL). Joint fluid analysis was performed in all patients and only crystal-proven gout patients were included in this study. At inclusion clinical characteristics and laboratory values were collected. At follow-up patients who died were identified. Standardized mortality ratios (SMRs) were calculated for all-causes, cardiovascular diseases, cancer, and infectious diseases using indirect standardization methods for mortality outcomes and compared with the general population. The clinical characteristics of the patients who died were compared with those of the survivors and were analyzed by a logistic regression analysis to identify any associations with mortality.

RESULTS

The study population at inclusion contained 573 (81.9%) men and 127 (18.1%) females with an average age of 62.0 (SD 13.4). During 3500 person-years from inclusion visit till 31 May 2016, in 700 gout patients, 66 deaths (27 cardiovascular deaths, 15 cancer-related deaths, 8 infectious deaths, 16 various other causes) occurred in this cohort. The all-cause standardized mortality ratio in gout patients was 2.21 (95% CI 1.68-2.74). In this cohort, gout patients had a higher SMR for death attributed to cardiovascular diseases (6.75; 95% CI 4.64-8.86), infectious diseases (4.66; 95% CI 1.51-7.82) and cancer (3.58; 95% CI 1.77-5.39). Corrected for confounders high serum uric acid levels (SUA; > 0,56 mmol/L), tophaceous gout, a history of peripheral vascular disease, myocardial infarction, and heart failure at the inclusion visit were associated with increased mortality during follow-up.

CONCLUSION

Compared to the general population, gout patients have an increased association with all-cause disease mortality, especially attributed to cardiovascular diseases, cancer, and infectious diseases. This association is strongest in hyperuricemic (uric acid levels > 0,56 mmol/l) and tophaceous patients and in those with a history of peripheral vascular disease, myocardial infarction, and heart failure. Preventive measures like treatment of high SUA levels and treatment of cardiovascular risk factors need to be considered and evaluated.

A meta-analysis of the association between gout, serum uric acid level, and obstructive sleep apnea

Previous epidemiological investigations have evaluated the association between gout, serum uric acid levels, and obstructive sleep apnea syndrome (OSAS), but with inconsistent results. We conducted this meta-analysis aiming at providing clear evidence about whether OSAS patients have higher serum uric acid levels and more susceptible to gout. Relevant studies were identified via electronic databases from inception to December 17, 2018. Study selection was conducted according to predesigned eligibility criteria, and two authors independently extracted data from included studies. The hazard ratio (HR) and weighted mean difference (WMD) and their corresponding 95% confidence interval (CI) were derived using random-effects models. We conducted meta-, heterogeneity, publication bias, sensitivity, and subgroup analyses. Eighteen studies, involving a total of 157,607 individuals (32,395 with OSAS, 125,212 without OSAS) and 12,262 gout cases, were included. Results show that serum uric acid levels are elevated in patients with OSAS (WMD = 52.25, 95% CI 36.16-64.33); OSAS did not reach statistical significance as a predictor of gout (but there was a trend, HR = 1.25, 95% CI 0.91-1.70) and that the association between OSAS and serum uric acid was quite robust. OSAS may be a potential risk factor for hyperuricemia and the development of gout and thus, effective OSAS therapy may present as a valuable preventive measure against gout. Still, it is vital to undertake clinical studies with better designing to corroborate these associations and shed new light on it.

Self-reported sleep quality and sleep disorders in people with physician-diagnosed gout: an Internet cross-sectional survey

Background

Limited information exists regarding sleep disorders in gout. Our objective was to assess the burden of sleep disorders in people with gout.

Methods

A brief anonymized Internet survey of people with physician-diagnosed gout who visited a gout education website assessed the frequency of sleep problems, sleep quality over the past 24 h (0 = best possible sleep, 10 = worst possible sleep), daytime sleepiness on a typical day (0 = none and 10 = most sleepy during the day), sleep quantity (number of hours of sleep), and the frequency of snoring or gasping, and snorting or stopping breathing during the sleep, using validated questionnaires, including the NHANES 2016 sleep questionnaire. We used Chi-square test to compare the categorical and t test the continuous variables.

Results

Of the 454 website visitors who clicked the survey, 320 survey respondents reported physician-diagnosed gout. Mean age was 57 years (standard deviation [SD], 13.4), 72% were male, 77% were White, and mean gout duration was 7.6 (SD, 11). Of the respondents, 23% reported doctor-diagnosed sleep disorder (sleep apnea, 17%; sleep study ordered, diagnosis pending, 4%; other sleep disorder 2%). A mean 6.7 h of sleep per night was reported (SD, 1.3). Eighty-six percent reported snoring during sleep and 45% reported having snorted, gasped, or stopped breathing while asleep. Two thirds of the patients reported feeling sleepy during the day, at least 3–4 times a month or more. Sleep quality was 5.5 (SD, 2.6), and daytime sleepiness was 3.5 (SD, 2.6) on a 0–10 scale (higher = worse).

Conclusions

People with physician-diagnosed gout reported frequent sleep disorders and daytime sleepiness in an Internet survey. More in-depth studies are needed to better understand the association of gout with sleep disorders.

The Risk of Gout Among Patients With Sleep Apnea: A Matched Cohort Study

OBJECTIVE

Obstructive sleep apnea (OSA) is associated with a range of serious comorbidities. This study was undertaken to investigate whether people with OSA are more likely to develop gout, in the short and long term, compared to those without OSA.

METHODS

A matched retrospective cohort study was undertaken using the UK Clinical Practice Research Datalink. Individuals age ≥18 years who received a diagnosis of OSA between 1990 and 2010 were identified and matched on age, sex, and practice with up to 4 individuals without OSA; follow-up was until the end of 2015. Hazard ratios (HRs) were estimated using Cox regression adjusted for general health, lifestyle, and comorbidity characteristics. The risk of developing gout was assessed at different time points, and the body mass index (BMI) category-specific results were presented.

RESULTS

The study sample included 15,879 patients with OSA and 63,296 without. The median follow-up was 5.8 years. We found that 4.9% of patients with OSA and 2.6% of patients without the disorder developed gout. The incidence rate per 1,000 person-years was 7.83 (95% confidence interval [95% CI] 7.29-8.40) and 4.03 (95% CI 3.84-4.23) among those with and without OSA, respectively. The adjusted HR was 1.42 (95% CI 1.29-1.56). The risk of developing gout among OSA patients compared to those without was highest 1-2 years after the index date (HR 1.64 [95% CI 1.30-2.06]). This finding persisted among those who were overweight and obese. For those with normal BMI, the highest significant HR (2.02 [95% CI 1.13-3.62]) was observed at 2-5 years after the index date.

CONCLUSION

In this study, patients with OSA continued to be at higher risk of developing gout beyond the first year following the diagnosis. Our results further indicate that peak incidences of gout vary according to BMI.

Gout and the Risk of Incident Obstructive Sleep Apnea in Adults 65 Years or Older: An Observational Study

STUDY OBJECTIVES

To assess whether gout is associated with a higher risk of obstructive sleep apnea (OSA) in older adults.

METHODS

We used the 5% United States Medicare beneficiary sample from 2006-2012 to assess whether gout was independently associated with new diagnosis of OSA in adults 65 years or older, adjusting for demographics, medical comorbidity (Charlson-Romano index) and hypertension, hyperlipidemia and coronary artery disease, and the use of medications for cardiovascular diseases or gout (allopurinol, febuxostat).

RESULTS

Based on 10,448,472 person-years of follow-up in a cohort of 1.74 million adults 65 years or older, the crude incidence rates of OSA were 14.3 per 1,000 person-years in people with gout and 3.9 per 1,000 person-years in people without gout. In multivariable-adjusted analyses, gout was associated with higher risk of a new diagnosis of OSA during the follow-up, hazard ratio was 2.07 (95% confidence interval [CI] 2.00, 2.15). In sensitivity analyses that substituted continuous Charlson-Romano score with a categorical variable or individual Charlson-Romano comorbidities plus hypertension, hyperlipidemia and coronary artery disease, the main finding was confirmed, hazard ratios were 2.11 (95% CI 2.03, 2.18) and 1.79 (95% CI 1.73, 1.85).

CONCLUSIONS

The independent association of gout with a twofold higher risk of OSA in older adults indicates that common mechanisms may be shared by the two conditions. More studies are needed to investigate these mechanisms further.

Comorbidity clusters in people with gout: an observational cohort study with linked medical record review

Objective

To investigate how comorbid conditions cluster in patients with gout in a UK primary care population.

Methods

A cross-sectional study was performed using baseline data from a primary-care-based prospective observational cohort of people aged ⩾18 years with gout. Participants with gout were identified through primary care medical records. Factor analysis was performed to obtain distinct clusters of comorbidity variables including obesity, hypertension, diabetes mellitus, hyperlipidaemia, coronary heart disease, heart failure, chronic kidney disease (CKD) and cancer. Hierarchical cluster analysis of patient observations was also performed to identify homogenous subgroups of patients based on combinations of their comorbidities.

Results

Four distinct comorbidity clusters (C1-C4) were identified in 1079 participants [mean (s.d.) age 65.5 years (12.5); 909 (84%) male]. Cluster C1 (n = 197, 18%) was the oldest group and had the most frequent attacks of gout; 97% had CKD. Participants in C2 (n = 393, 36%) had isolated gout with few comorbidities but drank alcohol more frequently. In cluster C3 (n = 296, 27%), hypertension, diabetes mellitus, hyperlipidaemia, coronary heart disease and/or CKD were prevalent, and urate-lowering therapy was prescribed more frequently than in other clusters. All patients in C4 (193, 18%) had hypertension and were more likely to be obese than other clusters.

Conclusion

Four distinct comorbidity clusters were identified. People with multiple comorbidities were more likely to receive allopurinol. Tailoring of treatments depending on cluster and comorbidities should be considered.

Prevalence and risk factors of hyperuricemia: results of the Kailuan cohort study

OBJECTIVE

The objective of this study is to determine the serum uric acid (SUA) level and the prevalence of hyperuricemia (HUA) in Chinese population.

METHODS

We conducted a cross-sectional study among 100,226 employees (79.9% male) of the Kailuan Group using physical examination data in 2006-2007. HUA was defined as SUA >356.9 μmol/L (6.0 mg/dL) for women and SUA >416.4 μmol/L (7.0 mg/dL) for men. We investigated crude and age adjusted HUA prevalence and compared characteristics of subjects with and without HUA in men and women using multivariate logistic regression.

RESULTS

SUA levels were 244.9 ± 71.5 μmol/L in women and 302.0 ± 83.5 μmol/L in men. About 8290 (8.27%) subjects were diagnosed with HUA. Age-adjusted prevalence of HUA was 8.02% in the total sample (6.87% in women and 8.57% in men). The SUA level and HUA prevalence showed U-shaped or J-shaped associations with age. Multivariate logistic regression revealed age, waist circumference, total cholesterol, triglyceride, hypertension and non-alcoholic fatty liver disease history, prolonged sitting, alcohol consumption, and oral diuretics were independent risk factors of HUA, while long sleep duration was protective against HUA.

CONCLUSIONS

The prevalence of HUA is 6.87% and 8.57% in Chinese women and men. HUA is likely related with life style and metabolic disorders.