Serious Infections in Patients With Gout in the US: A National Study of Incidence, Time Trends, and Outcomes

CAUSAL ROLES OF SERUM URIC ACID LEVELS AND GOUT IN SEPSIS: A MENDELIAN RANDOMIZATION STUDY

ABSTRACT

Objective: Several epidemiological studies have identified a potential link between serum uric acid (UA), gout, and sepsis. The primary objective of this study is to delve deeper into this connection, investigating the causal effect of UA and gout on sepsis by applying Mendelian randomization (MR). Methods: The causal relationship was analyzed using data from Genome-Wide Association Study (GWAS). Inverse variance weighting (IVW) was used as the main analysis method. Three complementary methods were used for our MR analysis, which included the MR-Egger regression method, the weighted median method, the simple median method. Horizontal pleiotropy was identified by MR-Egger intercept test. Cochran's Q statistics were employed to assess the existence of instrument heterogeneity. The leave-one-out method was used as a sensitivity analysis. Results: The IVW results indicated that there was a positive causal relationship between UA and sepsis (critical care) (odds ratio [OR] = 0.24, 95% confidence interval [CI]: 0.04 to 0.43, P = 0.018, F = 4,291.20). There was no significant association between UA and sepsis (28-day death in critical care) (OR = 0.10, 95% CI = -0.29 to 0.50, P = 0.604). There was no significant association between gout and sepsis (critical care) (OR = 0.85, 95% CI = -4.87 to 6.57, P = 0.771), and sepsis (28-day death in critical care) (OR = -6.30, 95% CI = -17.41 to 4.81, P = 0.267). Horizontal pleiotropy was absent in this study. The results were robust under all sensitivity analyses. Conclusion: The study revealed that elevated UA levels were causally linked with sepsis (critical care). No causal relationship had been found between UA and sepsis (28-day death in critical care), as well as between gout and sepsis.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

Hospitalized Infections in Patients With Rheumatic Disease Hospitalizations in Alaska, 2015-2018

OBJECTIVE

Rheumatic diseases are associated with increased rates of hospitalized infection, but few studies have included Indigenous North American populations. Our objective was to evaluate the association of rheumatic disease diagnosis during a hospitalization with odds of hospitalized infections in Alaska and assess differences by race.

METHODS

We used hospital discharge data from the Alaska Health Facilities Data Reporting Program from 2015 to 2018. We identified people with a rheumatic disease diagnosis based on any hospital discharge diagnosis of a set of rheumatic diseases and compared them to people hospitalized but without a rheumatic disease diagnosis. We determined odds of hospitalized infection by rheumatic disease diagnosis status and type, race, and type of infection. Using multivariable modeling, we determined factors associated with hospitalized infection.

RESULTS

Having a rheumatic disease diagnosis other than osteoarthritis was associated with 1.90 higher odds of hospitalized infection overall, whereas people of Alaska Native/American Indian (AN/AI) race with rheumatic disease had 2.44 higher odds. The odds varied by rheumatic disease and were increased in all rheumatic diseases except osteoarthritis (0.73). The most common type of hospitalized infection was sepsis, but opportunistic infections and pneumonia were most associated with a rheumatic disease diagnosis. On multivariable analysis, having a rheumatic disease diagnosis other than osteoarthritis, being of older age, and being of AN/AI race were associated with increased odds of hospitalized infection, with an interaction between race and rheumatic disease status.

CONCLUSION

This study confirmed the association of hospitalized infections with rheumatic disease diagnosis (other than osteoarthritis) during hospitalization and identified disparities by race.

Research progress on microRNA in gout

Gout is a common form of arthritis caused by the deposition of sodium urate crystals in the joints and tissues around them. MicroRNAs (miRNAs) are noncoding RNAs that have been shown to be involved in regulating the pathogenesis of gout through multiple cellular signaling pathways, which may be potential targets for the treatment of gout. In this review, we systematically discuss the regulatory roles of related miRNAs in gout, which will provide help for the treatment of gout and miRNAs is expected to become a potential biomarker for gout diagnosis.

Gout and Hospital Admission for Ambulatory Care-Sensitive Conditions: Risks and Trajectories

OBJECTIVE

To investigate the risks and trajectories of hospital admission for ambulatory care-sensitive conditions (ACSCs) in gout.

METHODS

Among individuals aged 35 years to 85 years residing in Skåne, Sweden, in 2005, those with no doctor-diagnosed gout during 1998 to 2005 (n = 576,659) were followed from January 1, 2006, until a hospital admission for an ACSC, death, relocation outside Skåne, or December 31, 2016. Treating a new gout diagnosis (International Classification of Diseases, 10th revision, code M10) as a time-varying exposure, we used Cox proportional and additive hazard models to estimate the effects of gout on hospital admissions for ACSCs. We investigated the trajectory of hospital admissions for ACSCs from 3 years before to 3 years after gout diagnosis using generalized estimating equations and group-based trajectory modeling in an age-and sex-matched cohort study.

RESULTS

Gout was associated with a 41% increased rate of hospital admission for ACSCs (hazard ratio 1.41, 95% CI 1.35-1.47), corresponding to 121 (95% CI 104-138) more hospital admissions for ACSCs per 10,000 person-years compared with those without gout. Our trajectory analysis showed that higher rates of hospital admission for ACSCs among persons with gout were observed from 3 years before to 3 years after diagnosis, with the highest prevalence rate ratio (2.22, 95% CI 1.92-2.53) at the 3-month period after diagnosis. We identified 3 classes with distinct trajectories of hospital admissions for ACSCs among patients with gout: almost none (88.5%), low-rising (9.7%), and moderate-sharply rising (1.8%). The Charlson Comorbidity Index was the most important predictor of trajectory class membership.

CONCLUSION

Increased risk of hospital admissions for ACSCs in gout highlights the need for better management of the disease through outpatient care, especially among foreign-born, older patients with comorbidities.

Relationship between hyperuricemia with deposition and sexual dysfunction in males and females

PURPOSE

The association between gout, the most common crystal arthropathy, and sexual dysfunctions has often been investigated by studies in the last decades. Despite the presence of shared risk factors and comorbidities and the possible effects on sexual health of long-term gout complications, awareness of this association is severely lacking and the pathogenetic mechanisms have only partially been identified. In the present review, we aimed to investigate the current evidence regarding the potential mechanisms linking sexual dysfunctions and gout.

METHODS

A comprehensive literature search within PubMed was performed to provide a summary of currently available evidence regarding the association between gout and sexual dysfunctions.

RESULTS

Gout and sexual dysfunctions share several risk factors, including diabesity, chronic kidney disease, hypertension, metabolic syndrome, and peripheral vascular disease. Gout flares triggered by intense inflammatory responses feature severe pain and disability, resulting in worse sexual function, and some, but not all, treatments can also impair sexual health. Long-term gout complications can result in persistent pain and disability due to joint deformity, fractures, or nerve compression, with negative bearing on sexual function. The presence of low-grade inflammation impairs both sex steroids synthesis and endothelial function, further advancing sexual dysfunctions. The psychological burden of gout is another issue negatively affecting sexual health.

CONCLUSIONS

According to currently available evidence, several biological and psychological mechanisms link sexual dysfunctions and gout. Addressing risk factors and providing adequate treatment could potentially have beneficial effects on both conditions. Appropriate clinical evaluation and multidisciplinary approach are recommended to improve patient care.

Hospitalizations Associated With Rheumatic Disease in Alaska, 2015-2018

Objective

Few studies have evaluated hospitalizations associated with rheumatic disease in Indigenous North American populations. The objective of this study was to determine the characteristics of people hospitalized with rheumatic disease in Alaska, including a comparison of hospitalizations for Alaska Native/American Indian (AN/AI) people in Alaska compared with those of other races.

Methods

We used statewide hospital discharge data from the Alaska Health Facilities Data Reporting Program from 2015 to 2018 for this study. Cases were ascertained based on discharge diagnosis (any listed) of a defined set of rheumatic diseases. We determined characteristics associated with rheumatic disease hospitalizations, including age, gender, and race. Using multivariate modeling, we determined risk factors for hospitalization overall, as well as for specific rheumatic diseases. We compared characteristics of hospital encounters for people with or without rheumatic diseases and by race.

Results

We identified 15975 people ever hospitalized with rheumatic disease in the study period and 87138 controls hospitalized but without any rheumatic disease diagnosis. Cases were older than controls and more likely to be female. The three most common types of rheumatic disease associated with hospitalization were osteoarthritis, gout, and rheumatoid arthritis. Compared with other races, AN/AI people were more likely to be hospitalized with rheumatic disease, and this association was true for all specific diseases other than gout.

Conclusion

Hospitalizations associated with rheumatic disease are common in Alaska, with an increased likelihood of hospitalization for AN/AI people. This adds to the literature on health disparities in Indigenous North American populations.

Incident Gout: Risk of Death and Cause-Specific Mortality in Western Sweden: A Prospective, Controlled Inception Cohort Study

Background

Excess mortality in gout has been attributed to cardiovascular diseases (CVD). Considering the decline in CVD mortality in the general population, we wanted to evaluate overall mortality in gout and cause-specific contributions to mortality beyond CVD and temporal trends.

Methods

All incident cases of gout between 2006 and 2015 in western Sweden and 5 population controls per case matched for age, sex, and county were identified. Comorbidities were identified for 5 years preceding the index date. Follow-up ended at death, migration, or end of study on December 2017. Effect of gout on death risk was calculated using COX regression on the whole population and stratified by sex, adjusted for demographics, and comorbidities. Death incidence rates were compared between the two time periods, 2006-2010 and 2011-2015.

Results

We identified 22,055 cases of incident gout and 98,946 controls, median age (Q1, Q3) 69-68 (57, 79/56, 78) years and 67.6-66.5% males. Except for dementia, all comorbidities were significantly more common at baseline among gout cases. Overall, the risk for death in incident gout was neither increased overall nor in men, but women had a 10% elevated risk. In adjusted models for cause-specific mortality, death from CVD, renal disease, and digestive system diseases were significantly increased in the total gout population while death from dementia, cancer, and lung diseases were significantly decreased. There were no significant differences in overall incident death rate ratios between cases and controls in the two time periods examined.

Conclusions

An increased risk for CVD, renal disease, and diseases of the digestive system in patients with gout highlights the importance of addressing CVD risk factors in gout management. Gout was associated with reduced mortality from dementia, which may have implications on urate lowering therapy and possible effects on dementia risk.

Death due to COVID-19 in a patient with diabetes, epilepsy, and gout comorbidities

There is evidence of increased incidence, rapid progression, and poor prognosis of COVID-19 in patients with underlying comorbidities such as diabetes and epilepsy. Developing effective treatment regimens for COVID-19 patients with multiple comorbidities is crucial, as patients' past medical history is an essential contributor to possible organ injuries in COVID-19 patients. Herein, we report a confirmed case of COVID-19 patient with a history of multiple underlying diseases, including diabetes, epilepsy, and gout. The patient developed multiple organ failure and died a week after intensive care unit (ICU) admission. Multiple organ failure is the most common cause of death in COVID-19 patients.