The association between time-mean serum uric acid levels and the incidence of chronic kidney disease in the general population: a retrospective study

Shengqing Jiangzhuo capsule ameliorates diabetic nephropathy by improving Keap1/Nrf2 signaling pathway

BACKGROUND

Diabetic nephropathy (DN) is a major contributor to end-stage renal failure, and lacking effective treatment options. Shengqing Jiangzhuo capsule (SQJZJN), a traditional Chinese medicine prescription with known efficacy in chronic kidney disease, has not been thoroughly investigated for its potential in DN protection.

METHODS

Eight-week-old male C57BLKS/J db/db, C57BLKS/J db/m mice, and human glomerular mesangial cell (HMC) cells cultured with high glucose were used as experimental models in this study.

RESULTS

The in vivo investigation showed that SQJZJN can significantly ameliorate renal pathological damage, reduce serum creatinine, and lower urinary microalbumin levels in db/db mice. In vitro, SQJZJN treatment mitigated advanced glycation end products (AGEs) and reactive oxygen species (ROS), leading to a reduction in renal cell apoptosis. Mechanistically, SQJZJN activated the Keap1/Nrf2/ARE pathway by promoting nuclear factor erythroid-derived 2-related factor 2 (Nrf2), γ-glutamylcysteine synthetase heavy subunit (γ-GCS), and Heme oxygenase-1 (HO-1) expressions, while decreasing Kelch-like ECH-associated protein 1 (KEAP1) expressions.

CONCLUSION

These findings suggest that SQJZJN exerts a protective effect on DN, potentially through the activation of the Keap1/Nrf2/ARE pathway.

The effect of metabolic factors on the association between hyperuricemia and chronic kidney disease: a retrospective cohort mediation analysis

BACKGROUND

Hyperuricemia, hyperglycemia, hypertension, hyperlipidemia, and hyperhomocysteinemia are all established risk factors for chronic kidney disease (CKD), and their interplay could exacerbate CKD progression. This study aims to evaluate the potential mediation effects of hyperglycemia, hypertension, hyperlipidemia, and hyperhomocysteinemia on the association between hyperuricemia (HUA) and chronic kidney disease (CKD).

METHODS

We collected electronic medical record data from 2055 participants who underwent physical examinations at the Affiliated Hospital of Qingdao University. The data were utilized to investigate the mediating effect of various factors including systolic blood pressure (SBP), diastolic blood pressure (DBP), homocysteine (HCY), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), blood glucose (Glu), and hemoglobin A1c (HbA1c) on the relationship between HUA and CKD.

RESULTS

Upon adjusting for confounding variables, mediation analysis indicated that only HCY acted as a mediator in the HUA-CKD relationship (p value < 0.05), exhibiting a statistically significant mediation effect of 7.04%. However, after adjustment for multiple testing, none of these variables were statistically significant.

CONCLUSIONS

Considering the observed associations between hyperuricemia, hyperglycemia, hypertension, hyperlipidemia, and CKD, none of the factors of interest remained statistically significant after adjusting for multiple testing as potential mediators of hyperuricemia on CKD.

Puerarin alleviates chronic renal failure-induced pyroptosis in renal tubular epithelial cells by targeting miR-342-3p/TGF-β/SMAD axis

BACKGROUND

Chronic renal failure (CRF) is the result of kidney damage. Puerarin is a flavonoid with specific nephroprotective effect, but its effect on CRF needs further research. This study explored the effect of puerarin on CRF and the potential molecular mechanism.

METHODS

Adenine was used to establish an in vivo CRF model in rats, and rats were intragastrically administered with puerarin at a dose of 400 mg/kg body weight once a day from day 1 to day 28. Hematoxylin and eosin (HE) and Masson staining were used to observe the morphology and fibrosis of kidney tissue. Lipopolysaccharide (LPS) (400 ng/mL)/H2O2 (200 µM) was applied to human kidney 2 (HK-2) cells to construct an in vitro CRF model. Enzyme-linked immunosorbent assay (ELISA) was performed to validate interleukin (IL)-1β and IL-18 levels. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was performed to detect microRNA (miR)-342-3p levels. Transforming growth factor beta (TGF-β)1, SMAD2, SMAD3, and pyroptosis marker proteins were detected by Western blot. The interaction between miR-342-3p and TGF-β/SMAD was determined by a dual-luciferase reporter gene assay. Cell Counting Kit-8 (CCK-8) assay was utilized to determine cell viability.

RESULTS

In the CRF model, puerarin alleviated renal injury and fibrosis and reduced creatinine (Cr) and blood urea nitrogen (BUN) levels. At the same time, miR-342-3p was downregulated, while the TGF-β/SMAD axis was activated and levels of IL-1β and IL-18 were increased. After treatment of CRF rats with puerarin, the expression level of miR-342-3p was increased, the TGF-β/SMAD axis was inhibited, and the secretion of IL-1β and IL-18 was decreased. MiR-342-3p directly bound to and negatively regulated the expression of TGF-β1, SMAD2, and SMAD3. In the in vitro CRF model, miR-342-3p inhibited HK-2 cell pyroptosis by inhibiting the TGF-β/SMAD axis.

CONCLUSION

Puerarin reduced renal injury and pyroptosis in CRF rats by targeting the miR-342-3p/TGF-β/SMAD axis.

Serum Uric Acid Levels and Their Association with Renal Function Decline and Kidney Disease Progression in Middle-Aged and Elderly Populations: A Retrospective Cohort Study

Objective

To evaluate the associations between serum uric acid (SUA) levels and estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD), with a focus on gender differences, and variations among women pre-and post-menopausal stages.

Design

A retrospective cohort study.

Setting

A large community-based survey was conducted every two years from 2010 to 2018 in Hangzhou, Zhejiang Province, Southeastern China.

Participants

10,218 participants (40 years or above) without CKD at baseline who underwent three physical examinations were enrolled. CKD was defined as an eGFR of less than 60 mL/min/1.73m2.

Methods

Participants with SUA levels were divided into four groups (Q1-Q4) based on baseline SUA quartiles. The Q1 was the reference. By stratifying participants by gender, the relationships between SUA levels and eGFR were investigated using the generalized additive mixture model. The associations of SUA and the risk of incident CKD were examined using multivariate logistic regression models in the generalized estimating equation.

Results

After adjusting for confounding variables, a nonlinear association between SUA and eGFR was observed in females, while an approximately linear relationship was observed in males, suggesting that elevated SUA levels are associated with renal function decline. Furthermore, the highest quartile of SUA was associated with a 2.16-fold (95% CI: 1.31-3.58) increased risk of CKD in males and a 2.76-fold (95% CI: 1.59-4.78) increased risk in females, compared with the lowest quartile. And the spline curves demonstrated a U-shaped pattern, suggesting a potential threshold effect of SUA on the risk of CKD. Additionally, Subgroup analyses revealed significant associations between elevated SUA levels with CKD in postmenopausal women, but not in premenopausal women.

Conclusion

Elevated SUA levels are associated with an increased risk of CKD development and renal function decline in middle-aged and elderly individuals, particularly in postmenopausal women.

Longitudinal changes in uric acid concentration and their relationship with chronic kidney disease progression in children and adolescents

BACKGROUND

Elevated serum uric acid concentration is a risk factor for CKD progression. Its change over time and association with CKD etiology and concomitant changes in estimated glomerular filtration rate (eGFR) in children and adolescents are unknown.

METHODS

Longitudinal study of 153 children/adolescents with glomerular (G) and 540 with non-glomerular (NG) etiology from the CKD in Children (CKiD) study. Baseline serum uric acid, change in uric acid and eGFR over time, CKD etiology, and comorbidities were monitored. Adjusted linear mixed-effects regression models quantified the relationship between within-person changes in uric acid and concurrent within-person changes in eGFR.

RESULTS

Participants with stable uric acid over follow-up had CKD progression which became worse for increased baseline uric acid (average annual percentage changes in eGFR were - 1.4%, - 7.7%, and - 14.7% in those with G CKD with baseline uric acid < 5.5 mg/dL, 5.5 - 7.5 mg/dL, and > 7.5 mg/dL, respectively; these changes were - 1.4%, - 4.1%, and - 8.6% in NG CKD). Each 1 mg/dL increase in uric acid over follow-up was independently associated with significant concomitant eGFR decreases of - 5.7% (95%CI - 8.4 to - 3.0%) (G) and - 5.1% (95%CI - 6.3 to - 4.0%) (NG) for those with baseline uric acid < 5.5 mg/dL and - 4.3% (95%CI - 6.8 to - 1.6%) (G) and - 3.3% (95%CI - 4.1 to - 2.6%) (NG) with baseline uric acid between 5.5 and 7.5 mg/dL.

CONCLUSIONS

Higher uric acid levels and increases in uric acid over time are risk factors for more severe progression of CKD in children and adolescents. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hyperuricemia—a serious complication among patients with chronic kidney disease: a systematic review and meta-analysis

Aim: Hyperuricemia as a putative risk factor for chronic kidney disease (CKD) progression remains controversial and debatable. This systematic review aims to explore the prevalence of hyperuricemia among CKD patients worldwide. Methods: This study was conducted in accordance with the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines by using the existing literature from online databases such as MEDLINE/PubMed, ScienceDirect, Google Scholar, Cochrane library and grey literature. The effect size with corresponding 95% confidence interval (CI) was calculated to assess the pooled prevalence of hyperuricemia in chronic kidney patients. The subgroup analysis based on gender and geography was also carried out by utilizing comprehensive meta-analysis, version 2.0. Results: Twenty-three studies containing 212,740 participants were eligible for quantitative synthesis. The pooled prevalence of 43.6% (35.2–52.4%) hyperuricemia was reported in patients with CKD globally. In India, 38.4% of prevalence was observed. The gender specific prevalence (9 studies) was reported as 67.4% (60.9–73.3%) in case of male patients and 32.6% (26.7–39.1%) in female patients with 95% CI. Conclusions: The prevalence of hyperuricemia was reported to be reasonably high among CKD patients worldwide. During the management of CKD, this high prevalence demands more prudent attention for this clinical complication which possibly can lead to positive renal outcomes.

A systematic review and meta-analysis of the association between uric acid levels and chronic kidney disease

The function of uric acid (UA) in the genesis and evolution of chronic kidney disease (CKD) has motivated numerous studies, but the results remain inconclusive. We sought to conduct a systematic review and meta-analysis of cohort studies aiming to analyze the association of UA levels with the incidence and progression of CKD. Pubmed/Medline, Lilacs/Bireme and Web of Science were searched to identify eligible studies, following the PRISMA protocol. Data were presented for CKD incidence and progression separately. For the meta-analysis, studies with data stratified by subgroups according to serum UA levels were selected. The inverse variance-weighted random effects model was used to generate a combined effect estimate. Meta-regressions were performed to identify the causes of heterogeneity. The Newcastle-Ottawa Scale was used to assess the risk of bias. The publication bias was tested by funnel plot and Egger's test. Eighteen CKD incidence studies (n = 398,663) and six CKD progression studies (n = 13,575) were included. An inverse relationship was observed between UA levels and protection from CKD incidence and progression. Lower UA levels were protective for the risk of CKD incidence (RR 0.65 [95% CI 0.56-0.75]) and progression (RR 0.55 [95% CI 0.44-0.68]). UA seems to be implicated both in the genesis of CKD and its evolution.

The Association between Baseline, Changes in Uric Acid, and Renal Failure in the Elderly Chinese Individuals: A Prospective Study with a 3-Year Follow-Up

OBJECTIVE

The objective is to find whether serum uric acid (SUA) levels are associated with the progression of chronic kidney disease (CKD) remains uncertain, and follow-up data among the elderly population are relatively lacking, especially in China. The aim of the present study was to reveal the association between baseline SUA levels, changes in SUA levels, and renal failure in Chinese elderly adults.

METHODS

In this retrospective cohort study, 425 subjects (age range 71-100 years) were analyzed and divided into quartiles based on baseline SUA levels (Q1: <4.8; Q2: <5.7; Q3: <6.5; and Q4: ≥6.5 mg/dl). CKD was defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². We used multiple linear and logistic regressions to compare the risk of renal dysfunction among the different SUA level groups.

RESULTS

The prevalence of hyperuricemia was 24.24% in the elderly subjects. In the multivariable analysis, the odds ratio (OR) for the development of CKD increased with the increase in SUA quartiles at baseline (1.00 vs. 1.79 (95% CI, 1.00-3.22), 3.4 (95% CI, 1.79-6.47), and 6.79 (95% CI, 3.45-13.75), respectively; P for linear trend <0.001), and a per unit increase in baseline SUA levels gave an OR of 1.76 (95% CI, 1.45-2.14) for renal failure. At the same time, a change in SUA levels had a stronger inverse correlation with a change in eGFR in females (r = -0.318, P < 0.001) than in males (r = -0.187, P < 0.01). In a linear regression analysis, a 1 mg/dl increase in SUA levels was associated with an additional 1.25 (95% CI, -1.83 to -0.67) ml/min/1.73 m² decrease in eGFR over a 3-year period.

CONCLUSION

Elevated baseline SUA levels and changes in SUA levels were associated with a decline in eGFR and an increased risk of CKD in an elderly Chinese population.

Quercetin alleviates chronic renal failure by targeting the PI3k/Akt pathway

Chronic renal failure (CRF) threatens human health greatly and attracts worldwide concerns of health professionals in the public health sector. In our preliminary study, we found that Compound capsule (Shengqing Jiangzhuo Capsule, SQJZJN) had a significant therapeutic effect on CRF. Quercetin is one of the main components of this Compound capsule. In this study, we investigated the effect of Quercetin monomer on CRF and the regulation of PI3k/Akt pathway. Network pharmacology analysis methods were employed to analyze the SQJZJN/Quercetin/PIK3R1 network relationships. In this study, a CRF rat model was prepared using the gavage adenine solution method and detected the indicators of Creatinine (Cr), Blood Urea Nitrogen (BUN), and Uric Acid (UA). After treating the rat model with Quercetin and PIK3R1-interfering lentivirus, respectively, we observed the changes on the histological morphology of the kidney and detected apoptosis using TUNEL staining. Gene and protein expression associated with renal function were detected using qPCR, WB and immunofluorescence. Quercetin was identified as the main ingredient of SQJZJN by the network pharmacological screening and Quercetin at 1.5 and 3 g/(kg.d) concentrations could effectively alleviate the CRF symptoms, reduce the levels of Cr, BUN, and UA, and markedly inhibit cell apoptosis demonstrated by the intragastric administration. Furthermore, the protein expression of p-PI3K, p-AKT, NLRP3, caspase1, AQP1, and AQP2 in all groups was detected by immunofluorescence and western blot assays, indicating that Quercetin could reduce the expression of NLRP3, caspase1, p-PI3k, and p-Akt, and increase the expression of AQP1 and AQP2 in the renal tissues of CRF rats. Being labeled with biotin and incubated with the total protein extracted from kidney tissues, Quercetin could bind to PIK3R1. Following the PIK3R1 interference lentivirus was injected into the CRF model rats by tail vein, the CRF symptoms were effectively alleviated in the PIK3R1 interference group, consistent with the effect of Quercetin. Taken together, Quercetin, a major component of SQJZJN, might minimize renal fibrosis and apoptosis in CRF rats by inhibiting the PI3k/Akt pathway through targeting PIK3R1. By regulating AQP1 and AQP2, both water retention and toxin accumulation were reduced.

Serum uric acid and risk of incident chronic kidney disease: a national cohort study and updated meta-analysis

BACKGROUND

We prospectively examined the association between serum uric acid (SUA) levels and chronic kidney disease (CKD) in China and updated the evidence through a comprehensive meta-analysis of prospective studies worldwide.

METHODS

Our original analyses were based on data from the China Health and Retirement Longitudinal Study. The primary exposure of interest was SUA at baseline, and the main outcome was incident CKD. Logistic regression models were used to examine the association between SUA levels and incident CKD. A meta-analysis was performed to pool our effect estimate and those from other cohort studies.

RESULTS

During a 4-year follow-up, 180 participants developed incident CKD. Participants in the highest SUA quartile were 2.73 times as likely to develop incident CKD compared to those in the lowest quartile (multivariable-adjusted OR, 2.73; 95% CI, 1.65-4.50). Each 1 mg/dL increment in the SUA levels was associated with a 49% increased risk of incident CKD (multivariable-adjusted OR, 1.49; 95% CI, 1.28-1.74). In the meta-analysis of 30 cohort studies (including the current study), pooled relative risks (95% CIs) of incident CKD were 1.15 (1.10-1.21) for SUA each 1 mg/dL increment, 1.22 (1.14-1.30) for the highest versus lowest SUA group, and 1.17 (1.12-1.23) for hyperuricemia versus no hyperuricemia.

CONCLUSIONS

Baseline SUA levels were associated with higher risk of incident CKD in middle-aged and elderly Chinese adults, and this positive association was confirmed in the meta-analysis of multiple cohort studies. Our findings may imply that SUA levels need to be routinely monitored for future CKD risk.

Hyperuricemia and chronic kidney disease: to treat or not to treat

Hyperuricemia is common in chronic kidney disease (CKD) and may be present in 50% of patients presenting for dialysis. Hyperuricemia can be secondary to impaired glomerular filtration rate (GFR) that occurs in CKD. However, hyperuricemia can also precede the development of kidney disease and predict incident CKD. Experimental studies of hyperuricemic models have found that both soluble and crystalline uric acid can cause significant kidney damage, characterized by ischemia, tubulointerstitial fibrosis, and inflammation. However, most Mendelian randomization studies failed to demonstrate a causal relationship between uric acid and CKD, and clinical trials have had variable results. Here we suggest potential explanations for the negative clinical and genetic findings, including the role of crystalline uric acid, intracellular uric acid, and xanthine oxidase activity in uric acid-mediated kidney injury. We propose future clinical trials as well as an algorithm for treatment of hyperuricemia in patients with CKD.

The association between dyslipidemia and the incidence of chronic kidney disease in the general Zhejiang population: a retrospective study

Background

According to the “lipid nephrotoxicity hypothesis”, there is now significant research being conducted in this area. By studying the role of hyperlipidemia in chronic kidney disease in the general Zhejiang population, we aimed to explore the correlation between changes in blood lipid levels and chronic kidney disease.

Methods

We collected and analyzed clinical data from ordinary residents who participated in the annual comprehensive physical examination with no overt kidney disease in Zhejiang Provincial People’s Hospital, China from January 2011 to December 2016. According to triglyceride, total cholesterol and low-density lipoprotein levels, participants were respectively divided into 4 groups. Statistical methods were used to evaluate the correlation between different blood lipid profiles and chronic kidney disease.

Results

Five thousand one hundred eighty-three participants were included in our study. During the six-year follow-up period, 227 participants (4.4%) developed chronic kidney disease. The odds ratio for incident chronic kidney disease was 3.14 (95%CI: 1.53–6.43) in Q3, 3.84 (95%CI: 1.90–7.76) in Q4 according to the total cholesterol group and 1.17 (95%CI: 1.04–1.32) in Q3, 1.40 (95%CI: 1.11–2.48) in Q4 according to the low-density lipoprotein group, respectively, after multivariable-adjusted analyses. According to the triglyceride grouping, the odds ratio for incident chronic kidney disease was 2.88 (95%CI: 1.29–6.43) in Q2, 2.92 (95%CI: 1.44–6.57) in Q3 and 3.08 (95%CI: 1.11–6.69) in Q4, after multivariable-adjusted analyses.

Conclusion

Increased triglycerides and high levels of total cholesterol and low-density lipoprotein were independently associated with an increased likelihood of estimated glomerular filtration rate (eGFR) decline and development of incident chronic kidney disease in the general Zhejiang population.

Genetically Elevated Serum Uric Acid and Renal Function in an Apparently Healthy Population

BACKGROUND

The association between uric acid and kidney disease has been extensively investigated. Numerous studies have reported the association between circulating levels of uric acid and renal function.

OBJECTIVES

To test, by the Mendelian randomization method, whether there is a causal association between circulating levels of uric acid and renal function.

METHODS

In 989 participants, estimated glomerular filtration rate (eGFR) was calculated, the circulating level of uric acid was tested, and the uric acid polymorphism (rs11722228) was genotyped.

RESULTS

After adjusting for age, gender, smoking history, alcohol intake, antihypertensive medication, body mass index, waist-to-hip ratio, and levels of urea nitrogen and creatinine, a significant allelic difference was found in uric acid levels for each genotype (p < 0.0001). Furthermore, the circulating levels of uric acid were negatively associated with eGFR after adjusting for cardiovascular risk factors and other potential confounders (p < 0.0001). Meanwhile, eGFR was significantly associated with the genotypes of rs11722228 (β = -0.07; p = 0.02).

CONCLUSIONS

Evidence from the Mendelian randomization approach implied a causal relationship between uric acid and renal function in an apparently healthy population.

Lower Diastolic Blood Pressure was Associated with Higher Incidence of Chronic Kidney Disease in the General Population Only in those Using Antihypertensive Medications

BACKGROUND/AIMS

The association of diastolic blood pressure (DBP) with incidence of chronic kidney disease (CKD) in the general population is not well examined.

METHODS

Using national health check-up database from 2008 to 2011 in the general Japanese population aged 39-74 years, we evaluated the association between DBP and incidence of CKD 2 years later in 127,954 participants without CKD. DBP was categorized by every 5 mm Hg from the lowest (<60 mm Hg) to the highest category (>100 mm Hg) and was further stratified into those with and without antihypertensive medications (BP meds). We calculated the OR for estimating adjusted risk of incident CKD using logistic regression model.

RESULTS

Participants were 62% female and 25.9% with BP meds, mean age of 76 years with estimated glomerular filtration rate of 78.2 ± 13.4 and DBP of 76 ± 11 mm Hg. Two years later, 12,379 (9.7%) developed CKD. Compared to DBP 60-64 mm Hg without BP meds as reference, multivariate analysis showed no difference in CKD risk at any DBP category among those without BP meds. However, in those with BP meds, risk increased according to lower DBP from 95 to 60 mm Hg (p for trend 0.05) with OR 1.51 (95% CI 1.14-1.99) in DBP <60 mm Hg. In subgroup analysis within those with or without BP meds, CKD risk was lower at higher DBP (p for trend 0.02) only in those without BP meds.

CONCLUSION

Lower DBP was associated with higher risk of incident CKD only in the general population taking antihypertensive medication.