Uric Acid Level as a Predictor of Long-Term Mortality in Advanced Age Population

Impact of Hyperuricemia on Clinical Outcomes in Sepsis Patients: A Retrospective Cohort Study

Background: Hyperuricemia has been linked to various adverse clinical outcomes. Data on the clinical outcomes and the relationship between hyperuricemia and sepsis remain limited. The aim of this study was to evaluate the impact of hyperuricemia on clinical outcomes in sepsis patients and to identify whether it can predict the mortality in this patient population. Methods: This was a retrospective cohort study of adult patients with sepsis admitted to the intensive care unit (ICU) from 1 January 2021 to 31 December 2023. The patients were divided into hyperuricemia and non-hyperuricemia groups. Hyperuricemia was defined as a serum uric acid level > 416.4 µmol/L (7.0 mg/dL) in males or >357.0 µmol/L (6.0 mg/dL) in females based on the first serum uric acid reading within 24 h of ICU admission. The primary outcome of this study was ICU mortality. Secondary outcomes included in-hospital mortality, progression to septic shock, and ICU and hospital lengths of stay (LOSs). Results: A total of 599 patients were included in the study. Among these, 303 were in hyperuricemia group, while 296 were in the non-hyperuricemia group. The incidence of ICU and in-hospital mortality was higher in the hyperuricemia group compared to the non-hyperuricemia group (26.7% vs. 18.9% (p < 0.001) and 34.7% vs. 19.3% (p < 0.001), respectively). After adjusting for cofounders, hyperuricemia was not a predictor of ICU mortality (OR 1.52, 95% CI 0.95-2.43, p = 0.083). Most secondary outcomes were similar between the groups. However, the hyperuricemia group had a higher incidence of progression to septic shock (67.3% vs. 50.7%, p < 0.001), and hospital LOS was significantly longer in the hyperuricemia group (384 vs. 264 h, p = 0.004). Conclusions: Our findings demonstrated that hyperuricemia in sepsis patients was associated with worse clinical outcomes such as higher ICU and hospital mortality. Moreover, there was a higher incidence of septic shock progression and longer hospital LOS. The other outcomes were not statistically significantly different. Further prospective research is warranted to confirm these findings.

Uric acid is a biomarker for heart failure, but not therapeutic target: result from a comprehensive meta-analysis

AIMS

This systematic review and meta-analysis aimed to investigate the association between serum uric acid (SUA) levels and the incidence rate and prognosis of heart failure (HF), as well as the impact of uric acid-lowering treatment on HF patients.

METHODS AND RESULTS

PubMed and Embase were searched for original articles reporting on the association between SUA and HF incidence, adverse outcomes, and the effect of uric acid-lowering treatment in HF patients. Data were pooled using random effects or fixed effects models. Univariable meta-regression analysis assessed the influence of study characteristics on research outcomes. Statistical analyses were conducted using RevMan software and STATA software version 15.0. Eleven studies on HF incidence and 24 studies on adverse outcomes in HF patients were included. Higher SUA levels were associated with an increased risk of HF (RR: 1.81, 95% CI: 1.53-2.16), all-cause mortality (RR: 1.44, 95% CI: 1.25-1.66), cardiac death (RR: 1.56, 95% CI: 1.32-1.84), and HF rehospitalization (RR: 2.07, 95% CI: 1.37-3.13) in HF patients. Uric acid-lowering treatment was found to increase all-cause mortality in HF patients (RR: 1.15, 95% CI: 1.05-1.25).

CONCLUSIONS

Uric acid is an independent predictor of heart failure occurrence and adverse prognosis. Targeting uric acid lowering as a therapeutic intervention does not improve the prognosis of patients with heart failure. It may not be advisable to use traditional urate-lowering drugs in young patients with heart failure, and elderly patients should exercise caution when using them.

The protective effects of uric acid against myocardial ischemia via the Nrf2 pathway

Uric acid (UA) possesses both pro- and anti-oxidative properties in ischemic heart disease, but the underlying mechanism remains unclear. We aimed to investigate UA's protective effect on myocardial ischemia by examining its effects on ECG Ischemic Alterations (EIA) and H2O2-induced oxidative stress in H9C2 myocardial cells. The incidence of EIA decreased over time and was more prevalent among women than men. A U-shaped relationship was observed between UA levels and EIA incidence, with the third quartile exhibiting a protective association. Addition of 237.9 μmol/L UA improved cellular damage and oxidative stress in H2O2-treated H9C2 cells, as determined by cell viability, LDH release, ROS levels, and total antioxidant capacity assays. UA activated the Nrf2 pathway, evidenced by increased expression of Nrf2, GCLC, and HO-1 proteins. By reversing cell cycle blockage, promoting wound healing ability, improving colony-forming capacity, and increasing angiogenesis in H2O2-treated cells, UA exhibited positive effects on cardiomyocyte growth characteristics. Additionally, use of Nrf2 inhibitor ML385 confirmed the involvement of the Nrf2 pathway by negating UA's effects on oxidatively damaged cardiomyocytes. Our findings suggest that UA induces downstream antioxidant factors to ameliorate oxidative stress by activating the Nrf2 pathway, which could be one of the targets responsible for UA's beneficial effects in myocardial ischemia.

The association of uric acid with mortality modifies at old age: data from the uric acid right for heart health (URRAH) study

OBJECTIVES

In older individuals, the role of serum uric acid (SUA) as risk factor for mortality is debated. This study investigated the association of SUA with all-cause and cardiovascular (CV) mortality in older adults participating in the large multicentre observational uric acid right for heart health (URRAH) study.

METHODS

Eight thousand URRAH participants aged 65+ were included in the analysis. The predictive role of SUA was assessed using Cox regression models stratified according to the cut-off age of 75. SUA was tested as continuous and categorical variable (age-specific quartiles). The prognostic threshold of SUA for mortality was analysed using receiver operating characteristic curves.

RESULTS

Among participants aged 65-74, multivariate Cox regression analysis adjusted for CV risk factors and comorbidities identified an independent association of SUA with both all-cause mortality (hazard ratio [HR] 1.169, 95% confidence interval [CI] 1.107-1.235) and CV mortality (HR 1.146, 95% CI 1.064-1.235). The cut-off value of 4.8 mg/dl discriminated mortality status. In participants aged 75+, we observed a J-shaped relationship of SUA with all-cause and CV mortality, with risk increasing at extreme SUA levels.

CONCLUSIONS

These results confirmed the predictive role of SUA for all-cause and CV mortality in older adults, while revealing considerable age-related differences. Mortality risk increased at higher SUA levels in participants aged 65-74, with a prognostic threshold of 4.8 mg/dl. The relationship between SUA and mortality was J-shaped in oldest participants. Large interventional studies are needed to clarify the benefits and possible risks of urate-lowering treatments in older adults.

Serum uric acid level and all-cause and cardiovascular mortality in peritoneal dialysis patients: A systematic review and dose-response meta-analysis of cohort studies

BACKGROUND

The association between serum uric acid (SUA) and all-cause and cardiovascular disease (CVD) mortality in peritoneal dialysis (PD) patients is controversial. Therefore, we aimed to determine the relationship between SUA and all-cause and CVD mortality in PD patients.

METHOD

Web of Science, EMBASE, PubMed and the Cochrane Library databases were searched from their inception to 7 April 2021. Effect estimates were presented as hazard ratios (HRs) with 95% confidence intervals (95% CIs) and pooled using random effects model.

RESULT

Thirteen cohort studies with 22418 patients were included in this systematic review, of which 9 were included in the meta-analysis. Before switching the reference group, pooled result for the highest SUA category was significantly greater than the median for all-cause mortality (HR = 2.41, 95% CI: 1.37-4.26). After switching the reference group, the highest SUA category did not demonstrate an increased all-cause (HR = 1.40, 95% CI: 0.95-2.05) or CVD (HR = 1.30, 95% CI: 0.72-2.34) mortality compared with the lowest SUA category. Dose-response analysis suggested a nonlinear association between SUA and all-cause mortality risk (Pnonlinearity = 0.002).

CONCLUSION

This meta-analysis didn't find the relationship between SUA levels and all-cause and CVD mortality risk in PD patients. More rigorously designed studies are warranted in the future.

Prognostic value of hyperuricemia for patients with sepsis in the intensive care unit

This study evaluated the relationship between hyperuricemia at admission and the clinical prognosis of patients with sepsis. The data were obtained from the Intensive Care Medical Information Database III. The patients were divided into a normal serum uric acid group and a hyperuricemia group. The main outcome was 90-day mortality, and the secondary outcomes were hospital mortality, 30-day mortality, and acute kidney injury. Propensity score matching was used to balance the baseline characteristics of the groups. Our study retrospectively included 954 patients. Before and after propensity score matching, the incidence of AKI, the 30-day and 90-day mortality rates were significantly higher in the hyperuricemia group. Cox regression analysis showed that hyperuricemia was significantly associated with 90-day mortality (HR 1.648, 95% CI 1.215–2.234, p = 0.006), and hyperuricemia was significantly associated with the incidence of AKI (HR 1.773, 95% CI 1.107–2.841, p = 0.017). The Kaplan–Meier survival curve showed that the 90-day survival rate was significantly lower in the hyperuricemia group. In patients with sepsis in the intensive care unit, hyperuricemia was significantly associated with increased risk 90-day all-cause mortality and the incidence of AKI.

Effect of Uric Acid-Lowering Agents on Patients With Heart Failure: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Background: Elevated serum uric acid (SUA) level is considered an independent predictor of all-cause mortality and the combined endpoint of death or readmission in cardiovascular disease patients. However, the causal relationship between uric acid-lowering therapies (ULTs) and heart failure is still controversial.

Design: Meta-analyses were performed to systematically compile available evidence to determine the overall effect of ULTs on heart failure patients.

Method: We conducted this systematic review following the PRISMA statement guidelines. Databases were searched to identify randomised controlled trials related to the influence of a ULT intervention in people with heart failure. Data extracted from the included studies were subjected to a meta-analysis to compare the effects of ULTs to a control.

Results: Pooled analysis of left ventricular ejection fraction (LEVF) showed an insignificant result towards the ULT group (MD, 1.63%; 95%CI, −1.61 to 4.88; p = 0.32; three studies). Pooled analysis of the 6-Minute Walk Test (6MWT) showed an insignificant result towards the ULT group (MD, 4.59; 95%CI, −12.683 to 22.00; p = 0.61; four studies). Pooled analysis of BNP/NT-pro-BNP led to a nearly statistically significant result towards the ULT group (SMD, −0.30; 95%CI, −0.64 to 0.04; p = 0.08; five studies). Pooled analysis of all-cause mortality and cardiovascular death between ULTs (all XOIs) and placebo did not show a significant difference (RR, 1.26; 95% CI, 0.74 to 2.15, p = 0.39).

Conclusion: ULTs did not improve LVEF, BNP/NT-pro-BNP, 6MWT, all-cause mortality, and CV death in heart failure patients. UA may just be a risk marker of heart failure.