Gout and the Risk of Incident Erectile Dysfunction: A Body Mass Index-matched Population-based Study

Uncovering the Potential Mechanisms and Effects of Hyperuricemia and its Associated Diseases on Male Reproduction

Male fertility and metabolic disorders, including obesity and diabetes, are closely connected. Since hyperuricemia and metabolic syndrome are strongly related, male fertility and hyperuricemia may, to some degree, be associated. According to recent studies, hyperuricemia imposes various effects on sex hormones, semen quality, and male erectile dysfunction. Some researchers claim that uric acid worsens male semen and raises the risk of erectile dysfunction (ED), while others state that it safeguards both penile erection and male semen. Additionally, it has been shown that gout and metabolic syndrome also raise the risk of ED. To clarify this controversy, the influence and potential mechanisms of hyperuricemia on ED, semen quality, sex hormone levels, and the effects of hyperuricemia-related disorders on ED will be comprehensively summarized.

The association between uric acid and erectile dysfunction in US adults: NHANES 2001-2004

BACKGROUND

-Recent evidence suggests that hyperuricemia may act as independent risk factors for erectile dysfunction (ED), in addition to the already established factors. The current evidence supporting this relationship remains insufficient.

METHODS AND RESULTS

-A total of 3,810 participants from the NHANES pool between 2001 and 2004 were included in our study, comprising 1,093 individuals with ED and 2,717 individuals without ED. Univariable and multivariable logistic regression analyses were conducted to examine the relationship between uric acid (UA) and the prevalence of ED. In the fully adjusted model, no significant association was observed between UA and ED (OR = 1.02, 95% CI: 0.84-1.24), and no significant differences were noted among the various UA levels (p = 0.5). In our sensitivity analyses, employing a stricter definition for ED, no significant results were found in the fully adjusted model (OR = 0.85, 95% CI: 0.60-1.19). Furthermore, no significant differences were observed among the various UA levels (p = 0.083).

CONCLUSIONS

-Our study did not establish a correlation between UA levels and ED. Nonetheless, further research with larger sample cohorts is required to verify these findings.

Risk of Erectile Dysfunction in Male Patients with Gout Treated with Febuxostat or Allopurinol: A Propensity Score-Matched Cohort Study

OBJECTIVE

To evaluate and compare the risk of erectile dysfunction (ED) associated with the use of allopurinol and febuxostat in adult male gout patients.

METHODS

We conducted a cohort study using TriNetX (Cambridge, MA, USA), a global federated health research network that provides real-time electronic medical record datasets. We analyzed and compared the associated risk of ED in gout patients who started taking allopurinol or febuxostat within 12 months. Propensity score matching was performed to adjust for demographic variables, comorbidities, and medication use. Kaplan-Meier analysis was used to estimate the probability of the outcome of interest. The hazard ratio (HR) and associated confidence intervals were calculated along with the proportionality test using R's Survival Package v3.2-3.

RESULTS

We identified 679,862 patients with gout among 107,517,445 patients in the database. Of these patients, 24,000 were treated with febuxostat and 299,726 with allopurinol. After propensity matching, 9075 patients receiving febuxostat without allopurinol (febuxostat group) and 9075 corresponding patients receiving allopurinol without febuxostat (allopurinol group) were analyzed for comparison. Among all male patients over 19 years of age, febuxostat was associated with a significantly higher risk of ED versus allopurinol (HR 1.354; 95% confidence interval (CI) 1.003-1.829; log rank test, p = 0.047). After subgroup analysis, in gout patients aged 19-64 years, a significantly higher incidence of ED was observed in the febuxostat group than in the allopurinol group (HR 2.002, 95% CI 1.282-3.126). The risk of ED did not differ significantly between the allopurinol and febuxostat groups in gout patients older than 65 years.

CONCLUSIONS

Febuxostat may be associated with a higher risk of ED than allopurinol in adult male patients with gout. Future large-scale prospective studies are warranted to confirm our results.

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.

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.

Hyperuricaemia is an important risk factor of the erectile dysfunction: A systematic review and meta-analysis

Serum uric acid can affect endothelial function, and hyperuricaemia-induced endothelial dysfunction is involved in the pathogenesis of cardiovascular diseases. As endothelial dysfunction is also a main pathogenic mechanism of erectile dysfunction (ED), the present study aims to evaluate the relationship between hyperuricaemia and ED via systemic review and meta-analysis. Five cohort studies and six cross-sectional studies on hyperuricaemia and ED, including a total of 454,510 participants, were recruited. Odds ratio (OR) and the 95% confidence intervals (CI) were adopted to estimate the relationship between hyperuricaemia and ED. Overall risk on effects of urate-lowering therapy (ULT) were analysed. In addition, subgroup analyses on study design, populations, age stratification and the object were conducted. In the patients with hyperuricaemia, the risk of ED was 1.59-fold higher than (pooled OR = 1.59, 95% CI [1.29, 1.97]) the non-hyperuricaemia counterparts. Urate-lowing therapy (ULT) in these hyperuricaemia patients reduced the risk of ED by 27% (OR = 1.27, 95% CI [1.14, 1.41]). After subgroup analysis, the association between hyperuricaemia and ED remained significant apart from the >60 years subgroup. Hyperuricaemia is an important risk factor of ED, while ULT can reduce the risk of ED in hyperuricaemia. This study suggests that hyperuricaemia-associated endothelial dysfunction may also underlie the pathogenesis of ED in these patients.

Erectile dysfunction in hyperuricemia: A prevalence meta-analysis and meta-regression study

BACKGROUND

Whether and to what extent an association exists between hyperuricemia and erectile dysfunction (ED) has not yet been fully determined.

OBJECTIVE

To define pooled prevalence estimates and correlates of erectile dysfunction in men with hyperuricemic disorders.

MATERIALS AND METHODS

A thorough search of Medline, Scopus, and Cochrane Library databases was performed. Data were combined using random-effects models and the between-study heterogeneity was assessed by Cochrane's Q and I² tests. A funnel plot was used to assess publication bias.

RESULTS

Overall, 8 studies included gave information about 85,406 hyperuricemic men, of whom 5023 complained of erectile dysfunction, resulting in a pooled erectile dysfunction prevalence estimate of 33% (95% Confidence Interval: 13-52%; I² = 99.9%). The funnel plot suggested the presence of a publication bias. At the meta-regression analyses, among the available covariates that could affect estimates, only type 2 diabetes mellitus was significantly associated with a higher prevalence of erectile dysfunction (β = 0.08; 95% Confidence Interval: 0.01, 0.15, p = 0.025). At the sub-group analysis, the pooled erectile dysfunction prevalence decreased to 4% (95% Confidence Interval: 0%-8%) when only the largest studies with the lowest prevalence of type 2 diabetes mellitus were included and increased up to 50% (95% Confidence Interval: 17%-84%) when the analysis was restricted to studies enrolling smaller series with higher prevalence of type 2 diabetes mellitus.

CONCLUSIONS

A not negligible proportion of men with hyperuricemia can complain of erectile dysfunction. While a pathogenetic contribution of circulating uric acid in endothelial dysfunction cannot be ruled out, the evidence of a stronger association between hyperuricemia and erectile dysfunction in type 2 diabetes mellitus points to hyperuricemia as a marker of systemic dysmetabolic disorders adversely affecting erectile function.

Beyond Arthritis: Understanding the Influence of Gout on Erectile Function: A Systematic Review

OBJECTIVE

To review the evidence suggesting a significant association between gout and erectile dysfunction (ED) and evaluate possible underlying pathways that may explain this relationship.

METHODS

English medical literature was searched from January 1, 2010, to January 1, 2020, for randomized or quasi-randomized controlled trials, cross-sectional studies, case-cohort studies, or meta-analysis evaluating the relationship between gout and ED.

RESULTS

All nine gout studies included in the study found a significant association between gout and ED. ED pathophysiology in gout involves hyperuricemia, increased reactive oxygen species, decreased nitric oxide synthesis, and low-grade inflammation.

CONCLUSION

The findings of this review suggest that the effect of urate-lowering therapy on the incidence of ED in gout patients should be studied. Additionally, we propose that all gout patients should be assessed for ED.

Gout is associated with elevated risk of erectile dysfunction: a systematic review and meta-analysis

Previous studies investigating the risk of erectile dysfunction (ED) among patients with gout have produced inconsistent evidence. Therefore, the aim of this meta-analysis was to investigate the relationship between gout and the risk of ED. The Embase, Medline, Scopus, Web of Science and Cochrane Library databases were searched for all studies assessing the risk of ED in patients with gout. Relative risks (RR) and corresponding 95% confidence intervals (CI) were adopted to estimate the association between gout and the risk of ED. Sensitivity analyses were applied to evaluate the robustness of results. Overall, 355,761 participants were included from 8 studies (3 cross-sectional and 5 cohort studies). Of these, 85,067 were patients with gout. Synthesis results showed patients with gout had a 1.2-fold higher risk of ED than individual without gout (RR 1.20, 95% CI 1.10-1.31, P < 0.001). The results of sensitivity analysis are consistent with the trend of synthesis results. The present meta-analysis revealed that the risk of ED in patients with gout was dramatically increased when compared with the general population, which suggests that clinicians should assess erectile function when treating an individual who suffers from gout.

Design of a Clinical Decision Support System for Predicting Erectile Dysfunction in Men Using NHIRD Dataset

Erectile dysfunction (ED) affects millions of men worldwide. Men with ED generally complain failure to attain or maintain an adequate erection during sexual activity. The prevalence of ED is strongly correlated with age, affecting about 40% of men at age 40 and nearly 70% at age 70. A variety of chronic diseases, including diabetes, ischemic heart disease, congestive heart failure, hypertension, depression, chronic renal failure, obstructive sleep apnea, prostate disease, gout, and sleep disorder, were reported to be associated with ED. In this study, data retrieved from a subset of the National Health Insurance Research Database of Taiwan were used for designing the clinical decision support system (CDSS) for predicting ED incidences in men. The positive cases were male patients aged 20-65 who were diagnosed with ED between January 2000 and December 2010 confirmed by at least three outpatient visits or at least one inpatient visit, while the negative cases were randomly selected from the database without a history of ED and were frequency (1:1), age, and index year matched with the ED patients. Data of a total of 2832 ED patients and 2832 non-ED patients, each consisting of 41 features including index age, 10 comorbidities, and 30 other comorbidity-related variables, were retrieved for designing the predictive models. Integrated genetic algorithm and support vector machine was adopted to design the CDSSs with two experiments of independent training and testing (ITT) conducted to verify their effectiveness. In the 1st ITT experiment, data extracted from January 2000 till December 2005 (61.51%, 1742 positive cases and 1742 negative cases) were used for training and validating and the data retrieved from January 2006 till December 2010 were used for testing (38.49%), whereas in the 2nd ITT experiment, data in the training set (77.78%) were extracted from January 2000 till Deceber 2007 and those in the testing set (22.22%) were retrieved afterward. Tenfold cross validation and three different objective functions were adopted for obtaining the optimal models with best predictive performance in the training phase. The testing results show that the CDSSs achieved a predictive performance with accuracy, sensitivity, specificity, g-mean, and area under ROC curve of 74.72%-76.65%, 72.33%-83.76%, 69.54%-77.10%, 0.7468-0.7632, and 0.766-0.817, respectively. In conclusion, the CDSSs designed based on cost-sensitive objective functions as well as salient comorbidity-related features achieve satisfactory predictive performance for predicting ED incidences.