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

Prediction of Acute Kidney Injury After Coronary Artery Bypass Graft From Preoperative Serum Uric Acid

OBJECTIVE

To examine the association of an elevated level of uric acid (UA) in the bloodstream with an increased likelihood of acute kidney injury (AKI) following coronary artery bypass grafting (CABG) surgery.

DESIGN

Retrospective cohort study using a multivariate logistic regression model.

SETTING

Single institution.

PARTICIPANTS

Recipients of CABG surgery.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

A total of 761 individuals who underwent CABG were included in the study. The participants were categorized into 4 groups based on their UA level: Q1 group (UA <292.5 μmol/L), Q2 group (292.5 ≤ UA <353 μmol/L), Q3 group (353 ≤ UA < 423 μmol/L), and Q4 group (UA ≥423 μmol/L). A total of 167 patients, accounting for 21.9% of the sample, experienced postoperative AKI. The study found a significantly higher risk of AKI in the Q4 group compared to the Q1 group (40.4% v 8.9%; p < 0.001). After adjustment for confounding variables, an independent association between serum UA concentration and an elevated risk of AKI post-CABG was identified (odds ratio, 6.41; 95% confidence interval, 3.49-12.32; p < 0.001; p for trend < 0.001).

CONCLUSIONS

There is a relationship between preoperative blood UA level and the occurrence of AKI following CABG surgery.

Uric acid promotes interleukin-17 expression to cause kidney injury

Uric acid, an oxidation end-product of purine metabolism, is reportedly to be a risk factor for kidney injury. However, its underlying mechanism is still a mystery. This study aimed to reveal the detailed roles of uric acid in inducing kidney injury and the possible mechanisms. Injection of rats with uric acid significantly increased tubular injury score, and levels of blood urea nitrogen, serum creatinine, and urine kidney injury molecule-1. Uric acid increased the expression of collagen I, alpha-smooth muscle actin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. Kyoto Encyclopedia of Genes and Genomes analysis result showed the IL-17 signaling pathway as the most significantly enriched pathway involved in hyperuricemia-related kidney injury. Long-term injection of uric acid induced significant production of IL-17 and recruitment of Th17 cells. Treating rats with the anti-IL-17 mAb attenuated uric acid-induced kidney injury, accompanied by the inactivation of nuclear factor-κB (NF-κB). In conclusion, uric acid was confirmed to be a risk factor for kidney injury via inducing IL-17 expression. Neutralization of IL-17 using the specific mAb relieved uric acid-induced kidney injury via inhibition of NF-κB signaling.

Cumulative burden of abnormal visceral adiposity index and its components on the risk of hyperuricemia

BACKGROUND AND AIMS

The visceral adiposity index (VAI), a gender-specific surrogate maker of adipose tissue distribution and function, is associated with risk of hyperuricemia. However, the impact of time-burden of abnormal VAI and its components on the risk of hyperuricemia remains unknown.

METHODS AND RESULTS

We included 56,537 participants without hyperuricemia and underwent two health examinations during 2006-2008 from the Kailuan study. Abnormal VAI burdens were evaluated as follows: (1) cumulative number of abnormal VAI presented at each examination (0-2 times); (2) cumulative number of each abnormal VAI component presented at each examination (0-2 times per component); (3) cumulative number of total abnormal VAI components presented at each examination (0-8 times). During a median follow-up of 8.81 years, 10,762 participants were diagnosed with hyperuricemia. The risk of hyperuricemia showed a positive association with cumulative number of abnormal VAI, the adjusted hazard ratio (HR) with 95% confidence interval (CI) of 2 times compared to 0 times was 1.69 (1.58-1.81). All four components of abnormal VAI, when diagnosed repeatedly, were independently associated with an increased risk of hyperuricemia, adjusted HR (95% CI) from 1.15 (1.02-1.28) for low high-density lipoprotein to 1.68 (1.58-1.79) for elevated triglyceride. The risk of hyperuricemia also gradually as abnormal components was accumulated from 0 to 8 counts, reaching an adjusted HR (95% CI) of 3.72 (2.64-5.23). Furthermore, the effect of cumulative abnormal VAI was more pronounced in females than males (P-interaction < 0.0001).

CONCLUSIONS

Cumulative abnormal VAI burdens were positively associated with the risk of hyperuricemia, especially in females.

Plasma S-Klotho level affects the risk of hyperuricemia in the middle-aged and elderly people

BACKGROUND

Soluble Klotho (S-Klotho) is an anti-aging protein mainly secreted by the kidneys. Hyperuricemia is prevalent among middle-aged and elderly individuals, which affects the development of various chronic diseases. However, there are relatively few studies investigating the association between plasma S-Klotho levels and hyperuricemia in middle-aged and elderly individuals. This study sought to clarify the relationship between S-Klotho and the risk of hyperuricemia in middle-aged and elderly people.

METHODS

During 2007-2016, a total of 50,588 people participated in the National Health and Nutrition Examination Survey. Finally, 12,441 middle-aged and elderly people (aged 40-79) completed the soluble Klotho tests and had obtained complete data. S-Klotho was detected by ELISA kit, and the relationship between S-Klotho and hyperuricemia was assessed by multiple logistic regression. Hyperuricemia is defined as serum uric acid levels higher than or equal to 420 mmol/l in men and 360 mmol/l in women.

RESULTS

In the middle-aged and elderly, plasma S-Klotho levels were negatively correlated with hyperuricemia, and there was a saturation effect. The inflection point of S-Klotho was 927.8 pg/ml (logarithmic likelihood ratio test = 0.002). When plasma S-Klotho < 927.8 pg/ml, the prevalence of hyperuricemia in middle-aged and elderly individuals with higher levels of S-Klotho decreased by 25.6% compared with those with low levels of S-Klotho [Q4 vs Q1, OR: 0.744, 95%CI: (0.634, 0.874), P < 0.001]; In different age groups, S-Klotho had a significantly greater effect on hyperuricemia in middle-aged people [age: 40-65 years, Q4 vs Q1, OR (95%CI): 0.69 (0.58, 0.82), P < 0.001; Age > 65 years: Q4 vs Q1, OR (95%CI): 0.72 (0.56, 0.92), P = 0.008)].When the level of S-Klotho was higher, the risk of hyperuricemia in men was lower than that in women [male: Q4 vs Q1, OR (95%CI): 0.67 (0.56, 0.81), P < 0.001; female: Q4 vs Q1 (95%CI):0.72 (0.58, 0.88), P < 0.001].

CONCLUSIONS

In middle-aged and elderly individuals, plasma S-Klotho levels were inversely correlated with hyperuricemia, with a saturation effect. Given the limitations of the research results, the underlying mechanism between S-Klotho and hyperuricemia should be further explored.

Prediction model of acute kidney injury after different types of acute aortic dissection based on machine learning

Objective

A clinical prediction model for postoperative combined Acute kidney injury (AKI) in patients with Type A acute aortic dissection (TAAAD) and Type B acute aortic dissection (TBAAD) was constructed by using Machine Learning (ML).

Methods

Baseline data was collected from Acute aortic division (AAD) patients admitted to First Affiliated Hospital of Xinjiang Medical University between January 1, 2019 and December 31, 2021. (1) We identified baseline Serum creatinine (SCR) estimation methods and used them as a basis for diagnosis of AKI. (2) Divide their total datasets randomly into Training set (70%) and Test set (30%), Bootstrap modeling and validation of features using multiple ML methods in the training set, and select models corresponding to the largest Area Under Curve (AUC) for follow-up studies. (3) Screening of the best ML model variables through the model visualization tools Shapley Addictive Explanations (SHAP) and Recursive feature reduction (REF). (4) Finally, the pre-screened prediction models were evaluated using test set data from three aspects: discrimination, Calibration, and clinical benefit.

Results

The final incidence of AKI was 69.4% (120/173) in 173 patients with TAAAD and 28.6% (81/283) in 283 patients with TBAAD. For TAAAD-AKI, the Random Forest (RF) model showed the best prediction performance in the training set (AUC = 0.760, 95% CI:0.630–0.881); while for TBAAD-AKI, the Light Gradient Boosting Machine (LightGBM) model worked best (AUC = 0.734, 95% CI:0.623–0.847). Screening of the characteristic variables revealed that the common predictors among the two final prediction models for postoperative AKI due to AAD were baseline SCR, Blood urea nitrogen (BUN) and Uric acid (UA) at admission, Mechanical ventilation time (MVT). The specific predictors in the TAAAD-AKI model are: White blood cell (WBC), Platelet (PLT) and D dimer at admission, Plasma The specific predictors in the TBAAD-AKI model were N-terminal pro B-type natriuretic peptide (BNP), Serum kalium, Activated partial thromboplastin time (APTT) and Systolic blood pressure (SBP) at admission, Combined renal arteriography in surgery. Finally, we used in terms of Discrimination, the ROC value of the RF model for TAAAD was 0.81 and the ROC value of the LightGBM model for TBAAD was 0.74, both with good accuracy. In terms of calibration, the calibration curve of TAAAD-AKI's RF fits the ideal curve the best and has the lowest and smallest Brier score (0.16). Similarly, the calibration curve of TBAAD-AKI's LightGBM model fits the ideal curve the best and has the smallest Brier score (0.15). In terms of Clinical benefit, the best ML models for both types of AAD have good Net benefit as shown by Decision Curve Analysis (DCA).

Conclusion

We successfully constructed and validated clinical prediction models for the occurrence of AKI after surgery in TAAAD and TBAAD patients using different ML algorithms. The main predictors of the two types of AAD-AKI are somewhat different, and the strategies for early prevention and control of AKI are also different and need more external data for validation.

Hyperuricemia is associated with all-cause mortality among males and females: Findings from a study on Japanese community-dwelling individuals

Background

Serum uric acid (SUA) is a key determinant of cardiovascular diseases (CVDs). Studies have also shown that SUA independently impacts age-related health outcomes, although their findings differ between males and females. Furthermore, predictive data on all-cause mortality remain limited, particularly for the Japanese population. Thus, this study examined the association between SUA and survival prognosis among males and females based on a follow-up period of 7 or 19 years.

Methods

The study was based on 1,573 male (63 ± 14 years) and 1,980 female (65 ± 12 years) participants who participated in a Nomura Cohort Study in 2002 (Cohort 1) and 2014 (Cohort 2), and continued throughout the follow-up period. A basic resident register was referenced to derive the adjusted relative risk estimates for all-cause mortality. Finally, a Cox proportional hazards model analysis was conducted and was adjusted for possible confounders to estimate hazard ratios (HRs). 95% confidence intervals (CIs) were computed separately for male and female participants.

Results

Of the total 3,553 participants, 905 (25.5%) were deceased. Of these, 473 were male (30.1% of all males) and 432 were female (21.8% of all females). Hyperuricemia was defined in males with SUA levels of 8.5 mg/dL or higher, and in females with SUA levels of 7.5 mg/dL or higher, and was associated with a significantly increased HR for all-cause mortality (males: 1.67; 95% CI: 1.06-2.63; females: 2.17; 95% CI: 1.20-3.94). The data were further stratified based on age (< 65 years or ≥ 65 years), body mass index (BMI) (< 25.0 kg/m2 or ≥ 25.0 kg/m2), History of cardiovascular disease, estimated glomerular filtration rate (< 60 mL/min/1.73 m2 or ≥ 60 mL/min/1.73 m2), and presence of SUA-lowering medication. All stratified groups demonstrated a similar trend. The hyperuricemia group in particular reported a significant increase in HR. On the other hand, a U-shaped increase in HR was observed in those with BMI greater than 25 kg/m2 and SUA-lowering medication, but interaction effect was not significant.

Conclusions

Hyperuricemia is a key risk indicator for all-cause mortality in male and female community-dwelling individuals in Japan.

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.

Psoriatic arthritis with hyperuricemia: more peripheral, destructive, and challenging to treat

Objective

To study the impact of hyperuricemia on clinical presentation, severity, and associated comorbidities of psoriatic arthritis (PsA).

Methods

Retrospective bicentric case–control study performed in Strasbourg and Colmar, France, from 2009 to 2019. Patients with PsA (according to ICD-10 coding) and at least one available serum urate (SU) measurement were included. Demographic, comorbidities, clinical, and radiographic data were collected. Hyperuricemia was defined as SU level ≥ 360 µmol/L.

Results

We included 242 patients: 73 (30.2%) had hyperuricemia and 15 (6.2%) met 2015 ACR/EULAR criteria for gout. On univariate analysis, as compared with normo-uricemic patients, hyperuricemic patients were more frequently male (72.6% vs 39.1%, p = 1.6 × 10⁻⁶) with higher body mass index (30.9 vs 28.7 kg/m², p = 0.015) and more comorbidities (Charlson comorbidity index: 2.6 vs 1.8, p = 0.005). PsA started at an older age (47.5 vs 43 years, p = 0.016) was more polyarticular (56.2% vs 41.9%, p = 0.049) than axial (9.6% vs 22.8%, p = 0.019) and more destructive (52.8% vs 37.4%, p = 0.032). PsA patients with joint destruction more frequently had hyperuricemia than did others (37.6% vs 25.8%, p = 0.047). Multivariable analysis confirmed the association of hyperuricemic PsA with peripheral joint involvement (odds ratio 2.98; 95% confidence interval 1.15–7.75; p = 0.025) and less good response to treatment (0.35; 0.15–0.87; p = 0.024).

Conclusion

Patients with hyperuricemic PsA show poorer response to PsA treatment and have more peripheral and destructive joint damage than normo-uricemic patients.

Key Points • Gout and psoriatic arthritis (PsA) can co-exist in the same patient. • Monosodium urate crystals might have a deleterious impact on PsA. • Hyperuricemic PsA is more polyarticular, less frequently axial, and more destructive than normo-uricemic PsA. • PsA with hyperuricemia should lead to more personalized medicine.

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.

High uric acid level increases the risk of acute kidney injury in acute coronary syndrome patients

BACKGROUND

Both clinical and experimental evidence have been published over the past few decades supporting the existence of a close relationship between the elevated levels of serum uric acid with cardiovascular events and acute kidney injury (AKI). This study aimed to determine the effect of serum uric acid levels on the incidence of AKI in acute coronary syndrome (ACS) patients.

METHODS

A retrospective cohort study with a cross sectional design was performed. The research was conducted at Dr. Wahidin Sudirohusodo Hospital from October 2019 to December 2019. Nonrandom sampling was employed in the medical records. All patients who met the inclusion criteria were at > 18 years old and diagnosed with ACS with AKI. The demographic data of age, sex and serum uric acid levels were recorded. The data obtained were analyzed using the SPSS (Statistical Package for Social Sciences).

RESULTS

There were 158 subjects of ACS patients with AKI and 135 without AKI. There was a significant correlation between high uric acid levels with the incidence of AKI in ACS (p<0.001). Patients with high serum uric acid levels were 9.5 times at risk of developing AKI compared to those with normal serum uric acid levels.

CONCLUSION

High uric acid level is one of the risk factors for AKI in ACS and indicates 9.5 times at risk of developing AKI compared to normal serum uric acid level. Therefore, it is necessary to monitor serum uric acid level and kidney function in ACS patients.

Clinicopathological characteristics and outcomes of anti-neutrophil cytoplasmic autoantibody-related renal vasculitis with hyperuricemia: a retrospective case-control study

The objective of the study was to evaluate the clinicopathological characteristics and investigate the clinical determinants of patient and renal survival in the first 12 months after diagnosis in anti-neutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis (AAV) patients with hyperuricemia. This was a retrospective case-control study in patients with AAV-related renal injury in the First Affiliated Hospital of Zhengzhou University from January 2014 to April 2019. Patients who met the study criteria were divided into two groups: patients without hyperuricemia (n = 92) and patients with hyperuricemia (n = 55). Participants were followed-up for 12 months, and progressing to end-stage renal disease (ESRD) and death was treated as the endpoint event. We found that the level of serum creatinine was an independent risk factor for hyperuricemia, and the level of serum uric acid was an independent risk factors for renal survival and patient survival in ANCA-associated renal vasculitis patients. The crescents formation and the proportion of fibrous crescent likely contributed to severe clinical characteristics and renal pathological changes in ANCA-associated renal vasculitis patients with hyperuricemia. Hyperuricemia has an important influence on the progression of ANCA-associated renal vasculitis. A good control of serum uric acid may improve the prognosis.

Uric acid fluctuation had no effect on renal function among gout patients

BACKGROUND AND AIMS

To investigate the effects of serum uric acid (SUA) level and its fluctuation on renal dysfunction in gout patients.

METHODS AND RESULTS

Data on gout patients was collected from Huzhou city electronic medical record system data sharing platform, and information about relevant diagnoses, prescriptions, biochemical indexes and imaging characteristics was extracted. The gout patients with baseline normal renal function were enrolled in this analysis, and the estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² was defined as renal dysfunction. The generalized estimating equation and Cox regression analysis were used. A total of 1009 patients with gout were enrolled. Compared with the reference group (normal baseline SUA with endpoint SUA to be < 6 mg/dL), endpoint SUA ≥ 10 mg/dL was associated with an increased risk of renal dysfunction (baseline normal SUA group: HR [95% CI] = 3.28 [1.21, 8.91]; baseline high SUA group: HR [95% CI] = 3.01 [1.43, 6.35]). Subgroup analysis of 771 SUA stable gout patients demonstrated that SUA levels at 8-10 (excluding 10), and ≥10 mg/dL were significantly associated with an increased risk for renal dysfunction, with HR [95%CI] to be 1.99 [1.05, 3.77], and 2.98 [1.38, 6.43], respectively.

CONCLUSION

Regardless of the baseline SUA level, SUA >10 mg/dL was a significant risk factor for renal dysfunction. SUA between 6 and 10 mg/dL was a potential risk factor for renal dysfunction. No significant correlation of SUA fluctuation and renal function was found.

Analyzing the Association between Hyperuricemia and Periodontitis: A Cross-Sectional Study Using KoGES HEXA Data

Hyperuricemia arises from the buildup of excessive uric acid in the blood, and it is implicated in the development of periodontitis. The objective of this study was to investigate the association between hyperuricemia and periodontitis using a cross-sectional study design and Korean Genome and Epidemiology Study Health Examinee (KoGES HEXA) data. This prospective cohort study used epidemiological data from the KoGES from 2004 to 2016. Among 173,209 participants, 8809 with hyperuricemia and 126,465 controls (non-hyperuricemia) were selected. This study defined hyperuricemia as >7.0 mg/dL of uric acid in men and >6.0 mg/dL in women. This study analyzed the history of periodontitis among hyperuricemia and control participants. Participants’ age, gender, income, obesity, smoking, alcohol consumption, and nutritional intake were all examined. Chi-square tests, independent t-tests, and two-tailed analyses were used for statistical analysis. The adjusted OR (aOR) of hyperuricemia for periodontitis was 0.89 (95% confidence interval (CI) = 0.81–0.96, p = 0.005). This study demonstrated that hyperuricemia was associated with periodontitis. This finding meant that elevated uric acid levels could have a positive effect on periodontitis. However, further studies should be performed to determine the range of uric acid levels beneficial to periodontal health.