Effects of hyperuricaemia, with the superposition of being overweight and hyperlipidaemia, on the incidence of acute kidney injury following cardiac surgery: a retrospective cohort study

OBJECTIVES

Acute kidney injury (AKI) is a common complication of cardiac surgery. This study aimed to explore the effects of hyperuricaemia, being overweight and hyperlipidaemia as risk factors for AKI in patients following cardiac surgery (cardiac surgery-associated acute kidney injury (CSA-AKI)).

DESIGN

Retrospective observational study.

SETTING

University teaching, grade-A tertiary hospital in Shanghai, China.

PARTICIPANTS

Patients who underwent cardiac surgery from July 2015 to December 2015 in Zhongshan Hospital, Fudan University.

MAIN OUTCOME MEASURES

We investigated the effect of hyperuricaemia, in combination with being overweight and hyperlipidaemia, on the risk of CSA-AKI.

RESULTS

A total of 1420 patients were enrolled. The AKI incidence in the highest uric acid group was 44.4%, while that in the lowest uric acid group was 28.5% (p<0.001). Patients in the higher uric acid quartiles were more likely to be overweight and hyperlipidaemic at the same time (p<0.001). Multivariate logistic regression analysis showed that hyperuricaemia was an independent risk factor for AKI (OR=1.237, 95% CI 1.095 to 1.885; p=0.009); being overweight or hyperlipidaemia alone was not an independent risk factor, but the combination of being overweight and hyperlipidaemia was (OR=1.544, 95% CI 1.059 to 2.252; p=0.024). In the final model, the OR value increased to 3.126 when hyperuricaemia was combined with being overweight and hyperlipidaemia, and the Hosmer-Lemeshow test showed that all three models fit well (p=0.433, 0.638 and 0.597, respectively).

CONCLUSIONS

The combination of being overweight and having hyperlipidaemia was an independent risk factor, but being overweight or having hyperlipidaemia alone was not. The combination of hyperuricaemia, being overweight and hyperlipidaemia further increased the risk of CSA-AKI.

Which risk predictors are more likely to indicate severe AKI in hospitalized patients?

OBJECTIVES

Acute kidney injury (AKI) is a sudden episode of kidney failure or damage and the risk of AKI is determined by the complex interactions of patient factors. In this study, we aimed to find out which risk factors in hospitalized patients are more likely to indicate severe AKI.

METHODS

We constructed a retrospective cohort of adult patients from all inpatient units of a tertiary care academic hospital between November 2007 and December 2016. AKI predictors included demographic information, admission and discharge dates, medications, laboratory values, past medical diagnoses and admission diagnosis. We developed a machine learning-based knowledge mining model and a screening framework to analyze which risk predictors are more likely to imply severe AKI in hospitalized populations.

RESULTS

Among the final analysis cohort of 76,957 hospital admissions, AKI occurred in 7,259 (9.43 %) with 6,396 (8.31 %) at stage 1, 678 (0.88 %) at stage 2, and 185 (0.24 %) at stage 3. We compared the non-AKI (without AKI) vs any AKI (stages 1-3), and mild AKI (stage 1) vs severe AKI (stages 2 and 3), where the best cross-validated area under the receiver operator characteristic curve (AUC) were 0.81 (95 % CI, 0.79-0.82) and 0.66 (95 % CI, 0.62-0.71), respectively. Using the developed knowledge mining model and screening framework, we identified 33 risk predictors indicating that severe AKI may occur.

CONCLUSIONS

This study screened out 33 risk predictors that are more likely to indicate severe AKI in hospitalized patients, which would help strengthen the early care and prevention of patients.

The relationship between hyperuricemia and contrast-induced acute kidney injury undergoing primary percutaneous coronary intervention: secondary analysis protocol for the ATTEMPT RESCIND-1 study

Background

Contrast-induced acute kidney injury (CI-AKI) contributes toward unfavorable clinical outcomes after primary percutaneous coronary intervention (pPCI). We will assess whether hyperuricemia is an independent predictor of CI-AKI and outcomes in patients undergoing pPCI.

Methods/design

Our study is a secondary analysis for the database from ATTEMPT study, enrolling 560 ST-segment elevation myocardial infarction (STEMI) patients undergoing pPCI. Patients will be divided into 2 groups according to the admission serum uric acid (SUA) level. Hyperuricemia will be defined as a SUA level > 7 mg/dL (417 mmol/L) in males and > 6 mg/dL (357 mmol/L) in females. The primary endpoint was CI-AKI, defined as > 25% or 0.5 mg/dL increase in serum creatinine from baseline during the first 48–72 h post-procedurally. Multivariate analyses for CI-AKI and long-term mortality will be performed using the logistic regression and Cox regression analyses, respectively.

Discussion

This study will determine the predictive value of hyperuricemia for the development of CI-AKI and outcomes in patients with STEMI undergoing pPCI. We predict that hyperuricemia will be associated with a risk of CI-AKI in patients with pPCI. Furthermore, after adjusting for other variables, long-term mortality after pPCI may be higher in those with hyperuricemia than in those with normouricemia. Results of this study may provide scientific evidence for the effect of hyperuricemia on CI-AKI and long-term outcomes, thereby offering the potential possibility of lowering SUA on the development of CI-AKI and outcomes.

Trial registration

ClinicalTrials.gov NCT02067195, Registered on 20 February 2014.

The incidence, risk factors, and long-term outcomes of acute kidney injury in hospitalized diabetic ketoacidosis patients

Background

Emerging evidence has demonstrated that acute kidney injury (AKI) is an important risk factor associated with increased morbidity and mortality in diabetic ketoacidosis (DKA) patients. The current study aimed to investigate the incidence rate, risk factors, long-term renal outcomes, and mortality in DKA patients with AKI.

Methods

A total of 179 patients diagnosed with DKA at Sun Yat-sen Memorial Hospital from January 2012 to January 2018 were included in the analysis. AKI was diagnosed according to the 2012 KDIGO criteria. Risk factors, long-term renal outcomes, and mortality were analyzed by logistic regression and Cox proportional hazards models.

Results

Among 179 DKA patients, 98 patients (54.75%) were diagnosed as AKI. Aging; increased blood glucose, serum uric acid and white blood cells; decreased serum pH and albumin; coma; and preexisting chronic kidney disease (CKD) were risk factors of AKI in patients with DKA. During follow-up, DKA patients with AKI showed more than a two-fold decline in eGFR within 1 year after discharge from the hospital when compared with non-AKI DKA patients. Furthermore, AKI was also an independent risk factor for poor long-term renal outcomes and mortality in DKA patients.

Conclusions

Multiple risk factors contribute to the development of AKI in DKA patients. AKI and advanced AKI stage are associated with rapid progressive CKD and long-term mortality in patients with DKA.

The Predictive Value of Hyperuricemia on Renal Outcome after Contrast-Enhanced Computerized Tomography

The aim of this study was to determine whether elevated serum level of uric acid (sUA) could predict renal outcome after contrast-enhanced computerized tomography (CCT). We used a historical cohort of 58,106 non-dialysis adult patients who received non-ionic iso-osmolar CCT from 1 June 2008 to 31 March 2015 to evaluate the association of sUA and renal outcome. The exclusion criteria were patients with pre-existing acute kidney injury (AKI), multiple exposure, non-standard volume of contrast, and missing data for analysis. A total of 1440 patients were enrolled. Post-contrast-AKI (PC-AKI), defined by the increase in serum creatinine ≥ 0.3 mg/dL within 48 h or ≥50% within seven days after CCT, occurred in 180 (12.5%) patients and the need of hemodialysis within 30 days developed in 90 (6.3%) patients, both incidences were increased in patients with higher sUA. sUA ≥ 8.0 mg/dL was associated with an increased risk of PC-AKI (odds ratio (OR) of 2.62; 95% confidence interval (CI), 1.27~5.38, p = 0.009) and the need of hemodialysis (OR, 5.40; 95% CI, 1.39~21.04, p = 0.015). Comparing with sUA < 8.0 mg/dL, patients with sUA ≥ 8.0 mg/dL had higher incidence of PC-AKI (16.7% vs. 11.1%, p = 0.012) and higher incidence of hemodialysis (12.1% vs. 4.3%, p < 0.001). We concluded that sUA ≥ 8.0 mg/dL is associated with worse renal outcome after CCT. We suggest that hyperuricemia may have potential as an independent risk factor for PC-AKI in patients receiving contrast-enhanced image study.

Hyperuricemia is associated with acute kidney injury and all-cause mortality in hospitalized patients

AIM

Hyperuricemia is a risk factor for high morbidity and mortality in several diseases. However, the relationship between uric acid (UA) and the risk of acute kidney injury (AKI) and mortality remain unresolved in hospitalized patients.

METHODS

Data from 18 444 hospitalized patients were retrospectively reviewed. The odds ratio (OR) for AKI and the hazard ratio (HR) for all-cause mortality were calculated based on the UA quartiles after adjustment for multiple variables. All analyses were performed after stratification by sex.

RESULTS

The fourth quartile group (male, UA > 6.7 mg/dL; female, UA > 5.4 mg/dL) showed a higher risk of AKI compared with the first quartile group (male, UA < 4.5 mg/dL; female, UA < 3.6 mg/dL), with the following OR: 3.2 (2.55-4.10) in males (P < 0.001); and 3.1 (2.40-4.19) in females (P < 0.001). There were more patients who did not recover from AKI in the fourth quartile compared with the first quartile, with the following OR: 2.0 (1.32-3.04) in males (P = 0.001) and 2.4 (1.43-3.96) in females (P = 0.001). The fourth quartile group had a higher risk of all-cause mortality compared with the first quartile group, with the following HR: 1.4 (1.20-1.58) in males (P < 0.001) and 1.2 (1.03-1.46) in females (P = 0.019). The in-hospital mortality risk was also higher in the fourth quartile compared with the first quartile, which was significant only in males (OR, 2.1 (1.33-3.31) (P = 0.002)).

CONCLUSION

Hyperuricemia increases the risks of AKI and all-cause mortality in hospitalized patients.

Uric acid and contrast-induced nephropathy: an updated review and meta-regression analysis

Introduction

Previous studies have suggested a relationship between serum uric acid and contrast-induced nephropathy (CIN).

Aim

We performed an updated review and a meta-regression analysis to assess whether serum uric acid is associated with CIN or there exists any relationship between serum uric acid and other risk factors for CIN.

Material and methods

We searched PubMed, Embase and Cochrane databases and reviewed cited references up to July 31, 2018 to identify relevant studies.

Results

A total of 6,705 patients from 10 clinical studies were included. CIN occurred in 774 of the 6,705 (12%) patients. Baseline uric acid levels were significantly higher in those who developed CIN (6.51 vs. 5.67 mg/dl; 95% CI: 0.55–1.22, p = 0.00001). Comparison of clinical features showed that patients with CIN were significantly older (69 vs. 63 years; p < 0.00001) and more often had diabetes (42% vs. 32%; p = 0.002) and hypertension (67% vs. 59%; p = 0.03). Also, patients who developed CIN had lower hemoglobin (12.5 vs. 13.6 mg/dl; p < 0.00001) and higher levels of baseline creatinine (1.27 vs. 1.01 mg/dl; p < 0.0001), but had similar levels of glycemia, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride. Also, they showed a lower ejection fraction (45% vs. 50%; p < 0.00001). Meta-regression analysis revealed that uric acid related only to age (r = 0.13, p = 0.03).

Conclusions

Our investigation indicates that uric acid is significantly associated with CIN. Uric acid correlated significantly with age only, and not with other major predictors of CIN. Further studies are therefore needed to verify the potential of uric acid to improve CIN risk stratification.

Feature Ranking in Predictive Models for Hospital-Acquired Acute Kidney Injury

Acute Kidney Injury (AKI) is a common complication encountered among hospitalized patients, imposing significantly increased cost, morbidity, and mortality. Early prediction of AKI has profound clinical implications because currently no treatment exists for AKI once it develops. Feature selection (FS) is an essential process for building accurate and interpretable prediction models, but to our best knowledge no study has investigated the robustness and applicability of such selection process for AKI. In this study, we compared eight widely-applied FS methods for AKI prediction using nine-years of electronic medical records (EMR) and examined heterogeneity in feature rankings produced by the methods. FS methods were compared in terms of stability with respect to data sampling variation, similarity between selection results, and AKI prediction performance. Prediction accuracy did not intrinsically guarantee the feature ranking stability. Across different FS methods, the prediction performance did not change significantly, while the importance rankings of features were quite different. A positive correlation was observed between the complexity of suitable FS method and sample size. This study provides several practical implications, including recognizing the importance of feature stability as it is desirable for model reproducibility, identifying important AKI risk factors for further investigation, and facilitating early prediction of AKI.

Hyperuricemia increases the risk of acute kidney injury: a systematic review and meta-analysis

Background

Mounting evidence indicated that the elevated serum uric acid level was associated with an increased risk of acute kidney injury (AKI). Our goal was to systematically evaluate the correlation of serum uric acid (SUA) level and incidence of AKI by longitudinal cohort studies.

Methods

We searched electronic databases and the reference lists of relevant articles. 18 cohort studies with 75,200 patients were analyzed in this random-effect meta-analysis. Hyperuricemia was defined as SUA levels greater than 360-420 μmol/L (6–7 mg/dl), which was various according to different studies. Data including serum uric acid, serum creatinine, and incidence of AKI and hospital mortality were summarized using random-effects meta-analysis.

Results

The hyperuricemia group significantly exerted a higher risk of AKI compared to the controls (odds ratio OR 2.24, 95% CI 1.76-2.86, p < 0.01). Furthermore, there is less difference of the pooled rate of AKI after cardiac surgery between hyperuricemia and control group (34.3% vs 29.7%, OR 1.24, 95% CI 0.96-1.60, p = 0.10), while the rates after PCI were much higher in hyperuricemia group than that in control group (16.0% vs 5.3%, OR 3.24, 95% CI 1.93-5.45, p < 0.01). In addition, there were significant differences in baseline renal function at admission between hyperuricemia and control groups in most of the included studies. The relationship between hyperuricemia and hospital mortality was not significant. The pooled pre-operative SUA levels were higher in AKI group than that in the non-AKI group.

Conclusions

Elevated SUA level showed an increased risk for AKI in patients and measurements of SUA may help identify risks for AKI in these patients.

Serum uric acid and acute kidney injury: A mini review

Acute kidney injury causes great morbidity and mortality in both the community and hospital settings. Understanding the etiological factors and the pathophysiological principles resulting in acute kidney injury is essential in prompting appropriate therapies. Recently hyperuricemia has been recognized as a potentially modifiable risk factor for acute kidney injury, including that associated with cardiovascular surgery, radiocontrast administration, rhabdomyolysis, and associated with heat stress. This review discussed the evidence that repeated episodes of acute kidney injury from heat stress and dehydration may also underlie the pathogenesis of the chronic kidney disease epidemic that is occurring in Central America (Mesoamerican nephropathy). Potential mechanisms for how uric acid might contribute to acute kidney injury are also discussed, including systemic effects on renal microvasculature and hemodynamics, and local crystalline and noncrystalline effects on the renal tubules. Pilot clinical trials also show potential benefits of lowering uric acid on acute kidney injury associated with a variety of insults. In summary, there is mounting evidence that hyperuricemia may have a significant role in the development of acute kidney injury. Prospective, placebo controlled, randomized trials are needed to determine the potential benefit of uric acid lowering therapy on kidney and cardio-metabolic diseases.

Hyperuricemia and contrast-induced acute kidney injury: A systematic review and meta-analysis

BACKGROUND

Hyperuricemia may be associated with an increased risk of contrast-induced acute kidney injury (CI-AKI). In recent years, studies about the relationship between them gradually appeared. We performed a systematic review and meta-analysis to investigate whether hyperuricemia is an independent risk factor for CI-AKI.

METHODS

Relevant studies were searched in PubMed, Embase, Cochrane Library, and CBM (Chinese Biomedical Literature database) databases until April 18, 2016, without language restriction. Observational studies evaluating serum uric acid (SUA) levels and CI-AKI risks were included. The pooled odds ratio was calculated to assess the association between hyperuricemia and risk of CI-AKI using a random-effects model.

RESULTS

Eighteen relevant studies involving a total of 13,084 patients met our inclusion criteria. Presence of hyperuricemia was associated with an increased risk of CI-AKI development regardless of whether the effect size was adjusted or not (unadjusted OR: 2.08, 95% CI: 1.63-2.64; adjusted OR: 1.68, 95% CI: 1.38-2.04). In-hospital mortality and cases of renal replacement therapy were significantly different between subjects with hyperuricemia and normouricemia undergoing coronary angiography (CAG) and/or percutaneous coronary intervention (PCI).

CONCLUSION

Hyperuricemia is independently associated with the occurrence of CI-AKI and it significantly increases the in-hospital mortality and the risk of renal replacement therapy among the patients after CAG and/or PCI. Future research is needed to determine whether urate-lowering therapy has beneficial effects for reducing the incidence of CI-AKI and in-hospital adverse events.

Effects of febuxostat on platelet-derived microparticles and adiponectin in patients with hyperuricemia

Platelet-derived microparticles (PDMPs) and adiponectin play an important role in the development of atherothrombosis. We investigated the effect of febuxostat on circulating PDMP levels and adiponectin in hyperuricemic patients. Levels of PDMP and biomarkers were measured using an ELISA at baseline and after 2 and 6 months of treatment. Plasma levels of PDMPs and biomarkers were higher, while those of adiponectin were lower in hyperuricemic patients than in normouricemic controls. Uric acid and interleukin (IL)-6 levels decreased significantly in hyperuricemic patients after 2 months of febuxostat treatment. However, PDMP and biomarkers decreased significantly in hyperuricemic patients after only 6 months of febuxostat treatment and adiponectin increased significantly. These results suggest that the effects of febuxostat for PDMPs seen may be the effect on xanthine oxidase but not the decrease of uric acid, and febuxostat may be beneficial for primary prevention of atherothrombosis in hyperuricemic patients.

Serum Uric Acid and Risk for Acute Kidney Injury Following Contrast

Contrast-induced acute kidney injury (CI-AKI) is a common cause of hospital-acquired acute kidney injury (AKI). We evaluated the evidence that uric acid (UA) plays a pathogenic role in CI-AKI. Ten studies were eligible for inclusion for meta-analysis. Hyperuricemia predicted risk for cases with AKI in prospective cohort studies. Higher levels of serum UA (SUA), as defined by the authors, were associated with a 2-fold increased risk to develop AKI (pooled odds ratio 2.03; 95% confidence interval [CI] 1.48-2.78). Significant heterogeneity was found in cohort studies ( P = .001, I² = 85.7%). In 2 clinical trials, lowering of SUA with saline hydration was significantly associated with reduced risk for AKI compared with saline hydration alone or saline hydration with N-acetyl cysteine. An analysis of 2 randomized controlled trials found that allopurinol with saline hydration had a significant protective effect on renal function (assessed by serum creatinine values) compared with hydration alone (mean difference: -0.52 mg/dL; 95% CI: -0.81 to -0.22). Hyperuricemia independently predicts CI-AKI. Two clinical trials suggest lowering SUA may prevent CI-AKI. The mechanism by which UA induces CI-AKI is likely related to acute uricosuria.

Long-term prognostic role of uric acid in patients with ST-elevation myocardial infarction and renal dysfunction

Patients with renal impairment have decreased excretion of uric acid, thus being particularly prone to having elevated serum uric acid concentrations. No data are available on the long-term prognostic role of uric acid in patients with ST-elevation myocardial infarction (STEMI) and renal dysfunction, submitted to percutaneous coronary intervention (PCI). We therefore prospectively assessed, in 329 patients with STEMI and renal dysfunction (admission estimated glomerular filtration rate <60 ml/min/1.73 m), all submitted to PCI, whether uric acid levels are associated with increased mortality at 1-year postdischarge follow-up.Patients in the third tertile of uric acid showed a higher BMI (P = 0.014), a higher incidence of hypertension (P = 0.029), and two or more comorbidities (P = 0.034). The highest incidence of bleeding and of acute kidney injury was detectable in patients in the third tertile (P = 0.011 and P < 0.001, respectively) who showed the highest mortality rate at 1-year postdischarge follow-up (P = 0.008). At Cox regression analysis, uric acid was an independent predictor of 1-year postdischarge mortality (hazard ratio 1.26, 95% confidence interval 1.06-1.51, P = 0.011).In STEMI patients with estimated glomerular filtration rate below 60 ml/min/1.73 m treated with PCI, uric acid helps in identifying a subset of patients at a higher risk of bleeding and acute kidney injury. Increased uric acid is an independent prognostic risk factor for 1-year mortality. Further studies performed in larger cohorts of patients are needed to confirm our findings and to evaluate whether lowering uric acid in these patients is beneficial.

Uric Acid is a Useful Tool to Predict Contrast-Induced Nephropathy

Developing contrast-induced nephropathy (CIN) after primary percutaneous coronary intervention (pPCI) has a negative impact on survival and morbidity. We assessed the predictive value of serum uric acid (SUA) for the development of CIN in patients with ST-segment elevation myocardial infarction (STEMI) who underwent pPCI. Contrast-induced nephropathy was defined an increase of ≥25% or ≥0.5 mg/dL in creatinine concentrations within 72 hours after pPCI. Patients were divided into 2 groups according to admission median SUA level. Serum uric acid level was <5.4 mg/dL (group 1; n = 222) and ≥5.4 mg/dL (group 2; n = 228). Compared to group 1, development of CIN (12% vs 20%, P < .001) was significantly greater in group 2. Using a cut point of >5.45 mg/dL, the SUA level predicted development of CIN with a sensitivity of 70% and specificity of 67%. In multiple logistic regression analysis, SUA level, diabetes mellitus, left ventricular ejection fraction <50%, contrast volume, estimated glomerular filtration rate, and C-reactive protein level emerged as independent predictors of CIN. In conclusion, elevated SUA is an independent risk factor for the development of CIN after pPCI in patients with STEMI.

Serum Uric Acid Levels and Renal Impairment among ST-Segment Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Intervention

BACKGROUND

Elevated serum uric acid (UA) levels are associated with adverse outcomes in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). However, the relation between UA and acute kidney injury (AKI) in this population is unclear. We evaluated the effect of elevated UA levels on the risk to develop AKI among consecutive STEMI patients treated with primary PCI.

METHODS

We performed a retrospective analysis of 1,372 consecutive patients admitted with the diagnosis of STEMI between January 2008 and February 2015. Patients were stratified into quartiles according to UA levels as follows: quartile 1, <4.7 mg/dl; quartile 2, 4.8 to <5.6 mg/dl; quartile 3, 5.7 to <6.6 mg/dl, and quartile 4, >6.7 mg/dl.

RESULTS

STEMI patients with elevated UA levels had a higher frequency of AKI (4 vs. 6% vs. 10 vs. 24%; p < 0.001). In a subgroup analysis of patients with reduced baseline estimated glomerular filtration rate (≤60 ml/min/1.73 m(2)), an elevated UA level was associated with a significant risk to develop AKI, with 46% of patients developing AKI in the highest UA quartile. In a multivariate logistic regression model, for every 1-mg/dl increase in the UA concentration, the adjusted risk for AKI increased by 46% (OR = 1.46, 95% CI 1.18-1.66; p < 0.001).

CONCLUSIONS

Among STEMI patients undergoing primary PCI, elevated UA levels are an independent predictor of AKI.

Acute kidney injury among ST elevation myocardial infarction patients treated by primary percutaneous coronary intervention: a multifactorial entity

Acute kidney injury is a frequent complication among ST segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI), and is associated with adverse outcomes. While contrast nephropathy is considered the most important reason for worsening of renal function, recent data have suggested the role of other important factors among this specific patient population. In the present review, we examine the various factors leading to renal impairment in STEMI patients and place the findings in the context of this specific patient population in the era of primary PCI. These factors include contrast nephropathy, time to coronary reperfusion, cardiac pump function and hemodynamics as well as various inflammatory and metabolic markers.

Metabolic syndrome, abdominal obesity and hyperuricemia in schizophrenia: Results from the FACE-SZ cohort

OBJECTIVE

Abdominal obesity was suggested to be a better predictor than Metabolic Syndrome (MetS) for cardiovascular mortality, however this is has not been extensively studied in schizophrenia. Hyperuricemia (HU) was also suggested to be both an independent risk factor for greater somatic comorbidity and a global metabolic stress marker in patients with schizophrenia. The aim of this study was to estimate the prevalence of MetS, abdominal obesity and HU, to examine the association between metabolic parameters with HU in a cohort of French patients with schizophrenia or schizo-affective disorder (SZ), and to estimate the prevalence rates of treatment of cardio-vascular risk factors.

METHOD

240 SZ patients (age=31.4years, male gender 74.3%) were systematically included. Metabolic syndrome was defined according to the International Diabetes Federation and HU if serum uric acid level was above 360μmol/L.

RESULTS

MetS, abdominal obesity and HU were found respectively in 24.2%, 21.3% and 19.6% of patients. In terms of risk factors, multiple logistic regression showed that after taking into account the potential confounders, the risk for HU was higher in males (OR=5.9, IC95 [1.7-21.4]) and in subjects with high waist circumference (OR=3.1, IC95 [1.1-8.3]) or hypertriglyceridemia (OR=4.9, IC95 [1.9-13]). No association with hypertension, low HDL cholesterol or high fasting glucose was observed. Only 10% of patients with hypertension received a specific treatment, 18% for high fasting glucose and 8% for dyslipidemia.

CONCLUSIONS

The prevalence of MetS, abdominal obesity and hyperuricemia is elevated in French patients with schizophrenia, all of which are considerably under-diagnosed and undertreated. HU is strongly associated with abdominal obesity but not with psychiatric symptomatology.

Admission hyperuricemia increases the risk of acute kidney injury in hospitalized patients(.)

Background

The association between elevated admission serum uric acid (SUA) and risk of in-hospital acute kidney injury (AKI) is limited. The aim of this study was to assess the risk of developing AKI in all hospitalized patients with various admission SUA levels.

Methods

This is a single-center retrospective study conducted at a tertiary referral hospital. All hospitalized adult patients who had admission SUA available from January 2011 through December 2013 were analyzed in this study. Admission SUA was categorized based on its distribution into six groups (<3.4, 3.4–4.5, 4.5–5.8, 5.8–7.6, 7.6–9.4 and >9.4 mg/dL). The primary outcome was in-hospital AKI occurring after hospital admission. Logistic regression analysis was performed to obtain the odds ratio (OR) of AKI of various admission SUA levels using the most common SUA level range (5.8–7.6 mg/dL) as the reference group.

Results

Of 1435 patients enrolled, AKI occurred in 263 patients (18%). The incidence of AKI and need for dialysis was increased in patients with higher admission SUA levels. After adjusting for potential confounders, SUA >9.4 mg/dL was associated with an increased risk of developing AKI, with ORs of 1.79 [95% confidence interval (CI) 1.13–2.82]. Conversely, admission SUA <3.4 and 3.4–4.5 mg/dL were associated with a decreased risk of developing AKI, with ORs of 0.38 (95% CI 0.17–0.75) and 0.50 (95% CI 0.28–0.87), respectively.

Conclusions

Elevated admission SUA was associated with an increased risk for in-hospital AKI.

Uric acid is highly associated with kidney allograft survival in a time-varying analysis

BACKGROUND

Hyperuricemia may be associated with the development of new cardiovascular events and graft loss in renal transplant recipients. This study was conducted to clarify whether hyperuricemia is a persistently independent predictor of long-term graft survival and patient outcome.

METHODS

Renal allograft recipients (n = 880) who underwent transplantation from December 1999 to March 2013 were included. Participants were divided into 2 groups: a hyperuricemic group (n = 389) and a normouricemic group (n = 491). The mean serum uric acid (UA) level was obtained by averaging all measurements, once per month for 3 months, before the study began. Clinical and laboratory data were collected. We investigated the role of hyperuricemia in the primary endpoint of graft failure by using time-varying analysis and Kaplan-Meier plots. All-cause mortality in renal transplant recipients was also surveyed.

RESULTS

During a mean follow-up of 43.3 ± 26.3 months, the major predisposing factors in the 389 patients with hyperuricemia were male predominance (62.98%), high entry serum UA (7.70; range 6.70-8.80 mg/dL), more hypertension (92.29%), previous hemodialysis mode (29.56%), hepatitis C infection (24.42%), more frequent use of UA-lowering agents (43.44%), and use of more drugs for inducing high serum UA (17.74%). After 12 months, the hyperuricemic group had persistently high serum UA (7.66 ± 2.00 vs 6.17 ± 1.60 mg/dL, P < .001) and poor renal function (serum creatinine 2.96 ± 3.20 vs 1.61 ± 1.96 mg/dL, P < .001) compared with the normouricemic group. Survival analysis showed the hyperuricemic group had poorer graft survival (60.47%) than the normouricemic group (75.82%, P = .0069) after 13-year follow-up. However, there was no difference in all-cause mortality between the 2 groups.

CONCLUSION

Persistently high serum UA seems to be implicated in elevation of serum creatinine, which could increase the risk for allograft dysfunction.

Hyperuricemia predicts kidney disease progression after acute allograft dysfunction

BACKGROUND

Hyperuricemia is associated with the development of new cardiovascular events and chronic allograft nephropathy in patients with decreased allograft function. This study investigates whether hyperuricemia in kidney transplant recipients should be considered as an independent predictor of kidney disease progression after acute allograft dysfunction.

METHODS

Between September 1, 2010, and December 31, 2012, 124 patients who underwent kidney graft biopsy for acute allograft dysfunction were enrolled. Participants were divided into 2 groups: A hyperuricemic group (n = 57) and a normouricemic group (n = 67). The mean serum uric acid (UA) level was obtained by averaging all measurements, once per month for 3 months, before the study began. Clinical and laboratory data were collected. We investigated the role of hyperuricemia on the composite end point (CEP) of doubling of serum creatinine and graft failure by using Cox regression and Kaplan-Meier plots.

RESULTS

Over a mean follow-up of 14.27 months, the hyperuricemic group had a poor cumulative survival and easily reached the CEP of doubling of serum creatinine and graft failure (P = .025) with a first-year cumulative incidence of 29.84% and a second-year cumulative incidence of 35.09%. Cox regression models revealed that age at biopsy (unadjusted hazard ratio [HR], 1.03; 95% CI, 1.00-1.06), hyperuricemia (HR, 2.24; 95% CI, 1.13-4.46), and interstitial fibrosis and tubular atrophy (IF/TA), including <25% of parenchyma affected (HR, 3.71; 95% CI, 1.34-10.31) and ≥ 25% of parenchyma affected (HR, 5.10; 95% CI, 1.83-14.19), were highly associated with poor outcome. After adjusting different variables, hyperuricemia and IF/TA were still significant.

CONCLUSION

Persistently high serum UA and IF/TA both contribute to the risk of kidney disease progression after acute allograft dysfunction.

Association of preoperative uric acid and acute kidney injury following cardiovascular surgery

OBJECTIVE

Recent studies suggested that elevated serum uric acid levels may be associated with the risk of acute kidney injury (AKI) in several settings. However, the effect of uric acid on the risk of AKI after cardiovascular surgery remains uncertain.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PARTICIPANTS

All consecutive adult patients (n = 1,019) who underwent cardiovascular surgery between January 2011 and May 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Preoperative and perioperative data were assessed in the study population. AKI was defined and staged as serum creatinine concentration-based Acute Kidney Injury Network criteria. Univariate and multivariate logistic regression analyses were conducted to evaluate the association between preoperative uric acid and postoperative AKI. Preoperative elevated uric acid (≥ 6.5 mg/dL) was associated independently with AKI after cardiovascular surgery (odds ratio 1.46; 95% confidence interval 1.04-2.06, p = 0.030). Results were the same in subgroup analyses. Preoperative elevated uric acid (≥ 6.5 mg/dL) also was associated with a higher incidence of prolonged ICU and hospital stay.

CONCLUSIONS

Preoperative elevated serum uric acid is an independent risk factor for AKI in patients undergoing cardiovascular surgery. This finding suggests that preoperative measurements of serum uric acid concentration may help stratify risks for AKI in these patients.

Uric acid levels, even in the normal range, are associated with increased cardiovascular risk: the Guangzhou Biobank Cohort Study

OBJECTIVE

To examine the association between serum uric acid (UA) levels and cardiovascular risk factors in subjects without diabetes or hyperuricemia.

METHODS

6172 women and 2662 men aged 50+ years without diabetes from Phase 1 of the Guangzhou Biobank Cohort Study were included. Data on personal history, physical examination and biochemical parameters were collected. Subjects were categorized by serum UA concentration, and the association between UA levels and cardiovascular risk factors was examined using generalized linear models.

RESULTS

In both men and women with normouricemia (UA<420 μmol/l in men and <360 μmol/l in women), tertiles of UA levels were adversely associated with body mass index, waist circumference, waist-to-hip ratio, total- and HDL-cholesterol, apolipoprotein A1, systolic and diastolic blood pressures, pulse pressure, fasting plasma glucose and white blood cell count (P value for trend ranged from 0.04 to <0.001), and also consistently associated with metabolic disorders including obesity, hypertension, hypertension treatment, dyslipidemia, waist circumference increased since the age of 18 years and the metabolic syndrome (P value for trend ranged from 0.02 to <0.001).

CONCLUSION

Increasing UA levels, even in subjects with normouricemia and without diabetes, were associated with increasing prevalence of cardiovascular risk factors, suggesting that clinically dichotomous definition of hyperuricemia may be inadequate and high-normal value of UA may warn of metabolic disorders.

The relationship between hyperuricemia and the risk of contrast-induced acute kidney injury after percutaneous coronary intervention in patients with relatively normal serum creatinine

OBJECTIVES

Hyperuricemia is a risk factor for contrast-induced acute kidney injury in patients with chronic kidney disease. This study evaluated the value of hyperuricemia for predicting the risk of contrast-induced acute kidney injury in patients with relatively normal serum creatinine who were undergoing percutaneous coronary interventions.

METHODS AND RESULTS

A total of 788 patients with relatively normal baseline serum creatinine (<1.5 mg/dL) undergoing percutaneous coronary intervention were prospectively enrolled and divided into a hyperuricemic group (n = 211) and a normouricemic group (n = 577). Hyperuricemia is defined as a serum uric acid level>7 mg/ dL in males and >6 mg/dL in females. The incidence of contrast-induced acute kidney injury was significantly higher in the hyperuricemic group than in the normouricemic group (8.1% vs. 1.4%, p<0.001). In-hospital mortality and the need for renal replacement therapy were significantly higher in the hyperuricemic group. According to a multivariate analysis (adjusting for potential confounding factors) the odds ratio for contrast-induced acute kidney injury in the hyperuricemic group was 5.38 (95% confidence interval, 1.99-14.58; p = 0.001) compared with the normouricemic group. The other risk factors for contrast-induced acute kidney injury included age >75 years, emergent percutaneous coronary intervention, diuretic usage and the need for an intra-aortic balloon pump.

CONCLUSION

Hyperuricemia was significantly associated with the risk of contrast-induced acute kidney injury in patients with relatively normal serum creatinine after percutaneous coronary interventions. This observation will help to generate hypotheses for further prospective trials examining the effect of uric acid-lowering therapies for preventing contrast-induced acute kidney injury.

On-admission serum uric acid predicts outcomes after acute myocardial infarction: systematic review and meta-analysis of prognostic studies

Aim

To evaluate the prognostic value of serum uric acid (SUA) in acute myocardial infarction (AMI) patients.

Methods

Systematic review and random-effects meta-analysis of prognostic studies assessing AMI outcomes (death, major adverse cardiac events, MACE) in relation to on-admission SUA.

Results

Nine studies (7655 patients) were identified, 6 in the ST-segment elevation AMI patients treated with invasive revascularization and three in mixed AMI type cohorts with variable reperfusion strategies. “High” SUA (vs “low,” different cut-offs) was univariately associated with higher short-term mortality (8 studies/6805 patients; odds ratio [OR], 3.24; 95% confidence interval [CI], 2.47-4.27) and incidence of MACE (7/6467; OR, 2.46; 95% CI, 1.84-3.27, moderate heterogeneity, mild bias), and with higher medium-term mortality (5/5194; OR, 2.69; 95% CI, 2.00-3.62, moderate heterogeneity, mild bias) and MACE (4/4299; OR, 1.93; 95% CI, 1.36-2.74, high heterogeneity, mild bias). It was independently associated with a higher short-term (4/3625; OR, 2.26, 95% CI, 1.85-2.77) and medium/long-term (3/2683; hazard ratio [HR], 1.30; 95% CI 1.01-1.68, moderate heterogeneity, mild bias) occurrence of poor outcomes (death/MACE). As a continuous variable (by 50 μmol/L), higher SUA was also independently associated with poorer medium/long-term outcomes (4/3533; HR, 1.19; 95% CI, 1.03-1.37, high heterogeneity, mild bias). All individual study effects (unadjusted or adjusted) were in the same direction, but differed in size. Heterogeneity was mainly due to the included AMI type and/or definition of MACE. All bias-corrected pooled effects remained significant.

Conclusion

Based on the available data, high(er) on-admission SUA independently predicts worse short-term and medium/long-term outcomes after AMI. However, the number of data are modest and additional prospective studies are warranted.

Usefulness of urinary biomarkers in early detection of acute kidney injury after cardiac surgery in adults

BACKGROUND

Acute kidney injury (AKI) is a common complication after cardiac surgery. Urinary liver-type fatty acid-binding protein (L-FABP) reflects the presence of renal tubular injury. The aim of the present study was to evaluate the utility of urinary L-FABP compared with other urinary biomarkers for the early detection of postoperative AKI among adult patients undergoing cardiac surgery.

METHODS AND RESULTS

Patients were divided into the AKI (n=48) and non-AKI groups (n=37) according to whether they developed postoperative AKI within 48h after surgery. Changes in various biomarkers were evaluated. Urine and serum samples were obtained from each patient at the following time points: before the operation, immediately after the operation, and 3, 6, 18, 24, and 48h postoperatively. The urinary L-FABP level was significantly higher in the AKI group than in the non-AKI group at every time point, while other biomarkers did not show such a tendency. The biomarker with the largest area under the curve at every time point for predicting the onset of AKI was urinary L-FABP. On multiple logistic regression analysis, the urinary L-FABP level before operation and within the first 6h after cardiac surgery was significantly associated with the onset of AKI.

CONCLUSIONS

Urinary L-FABP is a useful biomarker for early detection of AKI and is a good early predictor of the onset of AKI.