Serum uric acid level as an indicator for CKD regression and progression in patients with type 2 diabetes mellitus-a 4.6-year cohort study

Longitudinal Analysis of Renal Function Changes in Elderly Populations: Health Status Evaluation and Risk Factor Assessment

Background

This study aims to investigate GFR decline in elderly subjects with varying physical conditions and analyze key risk factors impacting renal function changes.

Methods

We obtained data from patients between 2017 and 2019, and matched healthy elderly subjects based on gender and age. Data collected for all subjects included annual measurements of fast blood glucose (GLU), glycated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-c), blood albumin (ALB), blood uric acid (UA), urine protein (UP), and systolic blood pressure (SBP). Additionally, information on coexisting diseases was gathered. The Full Age Spectrum (FAS) equation was used to calculate eGFR.

Results

A total of 162 patients with complete 3-year renal dynamic imaging were included, including 84 patients in the kidney disease group (K group) and 78 patients in the non-kidney disease group (NK group). Ninety individuals were selected as the healthy group (H group). The annual decline rate in the K group was the fastest, which exceeded 5mL/min/1.73m2 (P < 0.05). Group (K group: β=-40.31, P<0.001; NK group: β=-26.96, P<0.001), ALB (β=-0.38, P=0.038) and HbA1c (β=1.36, P=0.029) had a significant negative impact on the eGFR changes. For participants who had negative proteinuria: K group had the most significant annual eGFR decline.

Conclusion

The presence of kidney disease, along with proteinuria nor not, can lead to a marked acceleration in kidney function decline in elderly. We categorize elderly individuals with an annual eGFR decline of more than 5 mL/min/1.73m2 as the "kidney accelerated aging" population.

Interaction between anemia and hyperuricemia in the risk of all-cause mortality in patients with chronic kidney disease

Aim

Both hyperuricemia and anemia are not only the manifestation of chronic kidney disease (CKD) but also related to its occurrence and development. A recent study has found that there was a synergetic effect between hyperuricemia and anemia on new-onset CKD. Herein we aimed to explore the roles of hyperuricemia and anemia in the all-cause mortality in patients with CKD.

Methods

Data of adult patients with CKD were extracted from the National Health and Nutrition Examination Surveys (NHANES) database in 2009-2018 in this retrospective cohort study. Weighted univariate and multivariate COX regression analyses were used to investigate the associations of hyperuricemia and anemia with all-cause mortality, and the evaluation indexes were hazard ratios (HRs) and 95% confidence intervals (CIs). The interaction effect between hyperuricemia and anemia on the risk of all-cause mortality was assessed via relative excess risk due to interaction (RERI) and attributable proportion of interaction (AP). Subgroup analyses of age, gender, CVD, hypertension, DM, and cancer were also performed to assess this interaction effect.

Results

Among 3,678 eligible patients, 819 died from all causes. After adjusting for covariables, we found that CKD patients with anemia (HR = 1.72, 95%CI: 1.42-2.09) or hyperuricemia (HR = 1.21, 95%CI: 1.01-11.45) had a higher risk of all-cause mortality. There was a potential synergetic effect between anemia and hyperuricemia on all-cause mortality, with RERI of 0.630 and AP of 0.291. Moreover, this synergetic effect was also observed in ≥65 years old (AP = 0.330), male (AP = 0.355), hypertension (AP = 0.736), non-hypertension (AP = 0.281), DM (AP = 0.371), and cancer (AP = 0.391) subgroups.

Conclusion

A potential synergetic effect between anemia and hyperuricemia on all-cause mortality was found in patients with CKD. However, further studies are needed to clarify the causal relationship between them.

Uric acid and diabetes mellitus: an update

The relationship between diabetes mellitus (DM) and high serum uric acid is complex and controversial. Many epidemiological studies have reported a positive association, whereas others have reported an inverse association or none. In the pathogenesis of DM it is the intracellular urate that is more important than the extracellular and dissociation between the two is possible. Evidence suggests that high serum uric acid induces insulin resistance and beta cell failure in animal models. Reduction of intracellular uric acid can be achieved by dietary measures such as reducing fructose and salt intake, and uric acid-lowering drugs. We suggest that in the Western diet, these elements play a crucial role in pathogenesis of DM. To determine the precise and exact interrelationship between intracellular and extracellular uric acid, well-designed studies are required. Besides this, clinical trials are needed to determine whether intracellular and extracellular urate reduction will provide benefit in prevention and treatment of DM and complications associated with it.

Correlation between the increase in serum uric acid and the rapid decline in kidney function in adults with normal kidney function: a retrospective study in Urumqi, China

BACKGROUND

To examine the association between elevated serum uric acid (SUA) levels and the rapid decline in kidney function by conducting a retrospective cohort study on a physically healthy population in Urumqi, China.

METHODS

A cohort study of 2,802 physically healthy people with a normal estimated glomerular filtration rate (eGFR) was investigated from 2018 to 2021. The examination procedure included using questionnaires, taking physical measurements, and blood sampling. The rapid decline in kidney function was defined as eGFR > 5 mL·min^-1 ·(1.73 m² )^-1 year. The relationship between elevated SUA levels and the rapid decline in kidney function was assessed.

RESULTS

When performing the three-year retrospective analysis, 688 (28.55%) cases experienced a rapid decline in kidney function, and 52 (1.9%) cases developed chronic kidney disease (CKD). They were divided into the stable group and the rapidly declining kidney function group according to eGFR > 15 mL·min^-1·(1.73 m² )^-1. The comparison revealed a greater increase in uric acid in the rapidly declining kidney function group [0.30 (-0.29, 0.82) mg/dL vs. - 0.07(-0.54, 0.37) mg/dL, Z = - 8.822, P < 0.001]. The participants were further divided into four groups according to their uric acid levels in 2018 and 2021, which included the normal to normal (N-N) group, the normal to hyperuricemia (HUA) (N-H) group, the HUA to normal (H-N) group, and the persistently HUA (H-H) group. The decrease in eGFR was significantly higher in the N-H group than in the other three groups (χ² = 20.580, P < 0.001). The results of the multifactorial logistic regression analysis showed that elevated uric acid was a risk factor for the rapid decline in kidney function (OR = 1.640, P < 0.001).

CONCLUSION

Elevated SUA levels were a risk factor for the rapid decline in kidney function in the Chinese health examination population. Higher SUA levels might predict the occurrence of progressive kidney impairment.

Hyperuricemia Predicts the Progression of Type 2 Diabetic Kidney Disease in Chinese Patients

INTRODUCTION

Diabetic kidney disease (DKD) has a high global disease burden and substantially increases the risk of end-stage renal disease and cardiovascular events. High levels of serum uric acid (SUA), or hyperuricemia, may indicate patients with type 2 diabetes (T2D) at risk for kidney disease.

METHODS

This study explored the association between SUA levels and progression of kidney disease among patients with T2D. A cross-sectional study of 993 Chinese patients aged 20-75 years with T2D and DKD was conducted. Patients were stratified by progression risk of kidney disease based on estimated glomerular filtration rate and ratio of urinary albumin to creatinine, according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Ordinal logistic regression was used to assess associations between SUA and different KDIGO risk categories.

RESULTS

Among 768 patients in the final analysis, those with hyperuricemia and higher SUA were more likely to be assigned to higher KDIGO risk categories. Patients with SUA > 420 μmol/L were ninefold more likely to be in a higher KDIGO risk category than those with SUA < 300 μmol/L (odds risk 9.74, 95% confidence interval 5.47-17.33, P < 0.001).

CONCLUSIONS

Hyperuricemia may be associated with higher risk of DKD progression in individuals with T2D.

External validation of the risk prediction model for early diabetic kidney disease in Taiwan population: a retrospective cohort study

OBJECTIVES

This study aims to independently and externally validate the Risk Prediction Model for Diabetic Kidney Disease (RPM-DKD) in patients with type 2 diabetes mellitus (T2DM).

DESIGN

This is a retrospective cohort study.

SETTING

Outpatient clinics at Lee's United Clinics, Taiwan, China.

PARTICIPANTS

A total of 2504 patients (average age 55.44 years, SD, 7.49 years) and 4455 patients (average age 57.88 years, SD, 8.80 years) were included for analysis in the DKD prediction and progression prediction cohorts, respectively.

EXPOSURE

The predicted risk for DKD and DKD progression for each patient were all calculated using the RPM-DKD.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was overall incidence of DKD. Secondary outcomes included DKD progression. The discrimination, calibration and precision of the RPM-DKD score were assessed.

RESULTS

The DKD prediction cohort and progression prediction cohort consisted of patients with 2504 and 4455 T2DM, respectively. The RPM-DKD examined in this study showed moderately discriminative ability with area under the curve ranged from 0.636 to 0.681 for the occurrence of DKD and 0.620 to 0.654 for the progression of DKD. The Hosmer-Lemeshow χ² test indicted the RPM-DKD was not well calibrated for predicting the occurrence of DKD and overestimated the progression of DKD. The precision for predicting the occurrence and progression of DKD were 43.2% and 42.2%, respectively.

CONCLUSIONS

On external validation, the RPM-DKD cannot accurately predict the risk of DKD occurrence and progression in patients with T2DM.

Mediators of ertugliflozin effects on heart failure and kidney outcomes among patients with type 2 diabetes mellitus

AIMS

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to reduce the risk of hospitalization for heart failure (HHF) and composite kidney outcomes, but the mediators underlying these benefits are unknown.

MATERIALS AND METHODS

Among participants from VERTIS CV, a trial of patients with type 2 diabetes mellitus and atherosclerotic cardiovascular disease randomized to ertugliflozin versus placebo, Cox proportional hazards regression models were used to evaluate the percentage mediation of ertugliflozin efficacy on the first HHF and kidney composite outcome in 26 potential mediators. Time-dependent approaches were used to evaluate associations between early (change from baseline to the first post-baseline measurement) and average (weighted average of change from baseline using all post-baseline measurements) changes in covariates with clinical outcomes.

RESULTS

For the HHF analyses, early changes in four biomarkers (haemoglobin, haematocrit, serum albumin and urate) and average changes in seven biomarkers (early biomarkers + weight, chloride and serum protein) were identified as fulfilling the criteria as mediators of ertugliflozin effects on the risk of HHF. Similar results were observed for the composite kidney outcome, with early changes in four biomarkers (glycated haemoglobin, haemoglobin, haematocrit and urate), and average changes in five biomarkers [early biomarkers (not glycated haemoglobin) + weight, serum albumin] mediating the effects of ertugliflozin on the kidney outcome.

CONCLUSIONS

In these analyses from the VERTIS CV trial, markers of volume status and haemoconcentration and/or haematopoiesis were the strongest mediators of the effect of ertugliflozin on reducing risk of HHF and composite kidney outcomes in the early and average change periods.

GOV IDENTIFIER

NCT01986881.

1,2,3,4,6‑penta‑O‑galloyl‑β‑D‑glucose alleviates inflammation and oxidative stress in diabetic nephropathy rats through MAPK/NF‑κB and ERK/Nrf2/HO‑1 signaling pathways

Diabetic nephropathy (DN) is one of the main causes of chronic renal failure, which is also the final cause of mortality in ~30% of diabetic patients. 1, 2, 3, 4, 6-penta-O-galloyl-β-D-glucose (PGG) from Galla rhois has anti-inflammation, anti-oxidation and angiogenesis effects. The present study aimed to explore the protective effects on diabetic nephropathy rats by alleviating inflammation and oxidative stress and the underlying mechanism. High-fat diet/STZ induced rats and high glucose (HG) induced podocytes (MPC5) were used to simulate the DN in vivo and in vitro. The blood glucose level was measured using a blood glucose meter and renal function was determined by an automatic biochemical analyzer. The pathological changes and renal fibrosis were observed through hematoxylin and eosin, periodic acid-Schiff and Masson staining. The expression of nephrin in tissues, fibrosis-related proteins in tissues, MAPK/NF-κB and ERK/nuclear factor erythroid-derived 2-related factor 2 (Nrf2)/hemeoxygenase-1 (HO-1) signaling pathway related proteins in tissues and apoptosis related proteins in tissues and podocytes was detected by western blotting. The inflammatory response and oxidative stress in tissues and podocytes were determined by respective commercial kits and apoptosis in tissues and podocytes was detected by TUNEL assay. The viability of podocytes treated with PGG with or without HG was analyzed by CCK-8 assay. As a result, the blood glucose level, urinary albumin/creatinine ratio, blood urea nitrogen and serum creatinine in blood were all increased and nephrin expression was decreased. The pathological changes and renal fibrosis were aggravated and the inflammation, oxidative stress and apoptosis in renal tissues were enhanced. The above effects were reversed by PGG treatment dose-dependently. MAPK/NF-κB and ERK/Nrf2/HO-1 signaling pathways were activated in DN rats and were suppressed by PGG treatment. The reduced viability and increased apoptosis, inflammation and oxidative stress in MPC5 cells were shown in HG induction, which was reversed by PGG treatment. However, P79350 (p38 agonist) and LM22B-10 (ERK1/2 agonist) weakened the effect of PGG. In conclusion, PGG protects against DN kidney injury by alleviating inflammation and oxidative stress by suppressing the MAPK/NF-κB and ERK/Nrf2/HO-1 signaling pathways.

Serum uric acid levels and diabetic kidney disease in patients with type 2 diabetes mellitus: A dose-response meta-analysis

OBJECTIVE

Our study aimed to assess the existing evidence on whether serum uric acid (SUA) levels are associated with diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a systematic search of articles up to October 2021 in Medline, Embase, The Cochrane Library and Web of Science that estimated DKD by SUA levels in patients with T2DM. Pooled relative risks with 95% CI were calculated using random effects models RESULTS: A total of eight cohort studies involving 25,741 T2DM patients were included. Meta-analysis showed that compared the highest with the lowest category of SUA level, the summary risk ratios were 2.04 (95%CI 1.43-2.92, P < 0.001). The linear dose-response analysis revealed that the risk of DKD increased by 24% for each 1 mg/dl increase of SUA. The non-linear dose-response analysis also showed a significant relevance between SUA and the risk of DKD in patients with type 2 diabetes mellitus (P < 0.001).

CONCLUSIONS

Serum uric acid is associated with an increased risk of diabetic kidney disease in patients with type 2 diabetes mellitus. Serum uric acid level could be a good indicator for predicting diabetic kidney disease in patients with type 2 diabetes mellitus.

Hyperuricemia and diabetes mellitus when occurred together have higher risks than alone on all-cause mortality and end-stage renal disease in patients with chronic kidney disease

Introduction

Hyperuricemia and diabetes mellitus (DM) are associated with increased mortality risk in patients with chronic kidney disease (CKD). Here we aimed to evaluate the independent and joint risks of these two conditions on mortality and end stage kidney disease (ESKD) in CKD-patients.

Methods

This retrospective cohort study enrolled 4380 outpatients (with CKD stage 3–5) with mortality and ESKD linkage during a 7-year period (from 2007 to 2013). All-causes mortality and ESKD risks were analyzed by multivariable-adjusted Cox proportional hazards models (adjusted for age, sex, smoke, previous coronary arterial disease, blood pressure, and medications for hyperlipidemia, hyperuricemia and renin–angiotensin system inhibitors).

Results

Overall, 40.5% of participants had DM and 66.4% had hyperuricemia. In total, 356 deaths and 932 ESKD events occurred during the 7 years follow-up. With the multivariate analysis, increased risks for all-cause mortality were: hyperuricemia alone, HR = 1.48 (1–2.19); DM alone, and HR = 1.52 (1.02–2.46); DM and hyperuricemia together, HR = 2.12 (1.41–3.19). Similar risks for ESKD were: hyperuricemia alone, HR = 1.34 (1.03–1.73); DM alone, HR = 1.59 (1.15–2.2); DM and hyperuricemia together, HR = 2.46 (1.87–3.22).

Conclusions

DM and hyperuricemia are strongly associated with higher all-cause mortality and ESKD risk in patients with CKD stage 3–5. Hyperuricemia is similar to DM in terms of risk for all-cause mortality and ESKD. DM and hyperuricemia when occurred together further increase both risks of all-cause mortality and ESKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02755-1.

Uric Acid and Impairment of Renal Function in Non-diabetic Hypertensive Patients

Hyperuricemia is a risk factor for renal impairment. However, investigations focusing on patients with hypertension are limited and inconsistent. A single-center prospective cohort study of 411 Han Chinese non-diabetic hypertensive patients was conducted in Taiwan. The mean age of the participants was 62.0 ±14.4 years. The baseline estimated glomerular filtration rate and uric acid level were 86 mL/min/1.73 m² and 6.2 mg/dL, respectively. All patients underwent serum biochemistry tests for creatinine levels every 3 months. Renal events were defined as >25% and >50% decline in estimated glomerular filtration rate. During an average follow-up period of 4.7 ± 2.9 years (median 4.0 years), a >25 and >50% decline in estimated glomerular filtration rate was noted in 52 and 11 patients, respectively. The multivariate Cox regression analysis revealed that a baseline uric acid level ≥8.0 mg/dL increased the risk of >25% decline (hazard ratio: 3.541; 95% confidence interval: 1.655–7.574, P = 0.001) and >50% decline (hazard ratio: 6.995; 95% confidence interval: 1.309–37.385, P = 0.023) in estimated glomerular filtration rate. Similarly, a baseline uric acid level ≥7.5 mg/dL was independently associated with >25% decline (hazard ratio: 2.789; 95% confidence interval: 1.399–5.560, P = 0.004) and >50% decline (hazard ratio: 6.653; 95% confidence interval: 1.395–31.737, P = 0.017). However, this was not demonstrated at baseline uric acid level ≥7.0 mg/dL. Our study suggests that hyperuricemia is an independent risk factor for the decline in renal function in patients with hypertension. Uric acid level ≥7.5 mg/dL may be considered as the optimal cutoff value for clinical practice in predicting the development of renal impairment.

Development and External Validation of a Nomogram and a Risk Table for Prediction of Type 2 Diabetic Kidney Disease Progression Based on a Retrospective Cohort Study in China

PURPOSE

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide. Risk assessment provides information about patient prognosis, contributing to the risk stratification of patients and the rational allocation of medical resources. We aimed to develop a model for individualized prediction of renal function decline in patients with type 2 DKD (T2DKD).

PATIENTS AND METHODS

In a retrospective observational study, we followed 307 T2DKD patients and evaluated the determinants of 1) risk of doubling in serum creatinine (Scr), 2) risk of eGFR<15 mL/min/1.73m² using potential risk factors at baseline. A prediction model represented by a nomogram and a risk table was developed using Cox regression and externally validated in another cohort with 206 T2DKD patients. The discrimination and calibration of the prediction model were evaluated by the concordance index (C-index) and calibration curve, respectively.

RESULTS

Four predictors were selected to establish the final model: Scr, urinary albumin/creatinine ratio, plasma albumin, and insulin treatment. The nomogram achieved satisfactory prediction performance, with a C-index of 0.791 [95% confidence interval (CI) 0.762-0.820] in the derivation cohort and 0.793 (95% CI 0.746-0.840) in the external validation cohort. Then, all predictors were scored according to their weightings. A risk table with the highest score of 11.5 was developed. The C-index of the risk table was 0.764 (95% CI: 0.731-0.797), which was similar to the external validation cohort (0.763; 95% CI: 0.714-0.812). Additionally, the patients were divided into two groups based on the risk table, and significant differences in the probability of outcome events were observed between the high-risk (score >2) and low-risk (score ≤2) groups in the derivation and external validation cohorts (P < 0.001).

CONCLUSION

The nomogram and the risk table using readily available clinical parameters could be new tools for bedside prediction of renal function decline in T2DKD patients.

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.

Association of plasma fatty acid-binding protein 3 with estimated glomerular filtration rate in patients with type 2 diabetes mellitus

Background: Fatty acid-binding protein 3 (FABP3) located in renal mesangial and distal tubular cells, and had been shown to be a sensitive marker of renal injury, potentially be a mediator in pathogenesis of chronic kidney disease (CKD). Our previous study revealed that plasma FABP1 and FABP2 were independently associated with CKD, however, little is known about the relationship between plasma FABP3 level and CKD. The aim of this study was therefore to evaluate the plasma levels of FABP3 at different stages of estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes mellitus (T2DM). Methods: A total of 334 subjects with T2DM who enrolled in a disease management program were included in this study and stratified according to eGFR. Plasma FABP3 concentrations were measured by an enzyme-linked immunosorbent assay. Results: FABP3 levels increased in parallel with the eGFR level. Increasing concentrations of FABP3 were independently and significantly associated with eGFR stage G2-G4. Age- and sex-adjusted FABP3 levels were positively associated with uric acid, urinary albumin-to-creatinine ratio, FABP1, FABP2, and fatty liver index, but negatively associated with eGFR and hemoglobin. Conclusion: Our results indicate that circulating FABP3 in patients with T2DM is associated with eGFR, which suggests that increased plasma FABP3 may be involved in the pathogenesis of CKD.

Update on pathogenesis and diagnosis flow of normoalbuminuric diabetes with renal insufficiency

In recent decades, the prevalence of diabetic kidney disease has remained stable and appears to be a wide heterogeneity. Normoalbuminuric diabetes with renal insufficiency, which is characterized by a decline in the glomerular filtration rate in the absence of albuminuria, has been identified as an albuminuria-independent phenotype of diabetic kidney disease. Epidemiological data demonstrate that normoalbuminuric phenotype is prevalent. Compared to albuminuric phenotype, normoalbuminuric phenotype has distinct clinical characteristics and a wide heterogeneity of pathological features. Currently, the pathogenesis of normoalbuminuric phenotype remains unclear. Additionally, the flow of diagnosing normoalbuminuric phenotype is not perfect. In this article, we review the latest studies addressing the epidemiology, clinical characteristics, and pathology of normoalbuminuric phenotype. Based on the studies of clinical features and renal histopathologic changes, we attempt to propose an underlying pathogenesis model and a flow chart for diagnosing normoalbuminuric phenotype.

Association between serum uric acid and renal outcome in patients with biopsy-confirmed diabetic nephropathy

OBJECTIVE

To investigate the relationship between serum uric acid (SUA) level and renal outcome in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN).

METHODS

A total of 393 Chinese patients with T2DM and biopsy-proven DN and followed at least 1 year were enrolled in this study. Patients were stratified by the quartiles of baseline level of SUA: Q1 group: 286.02 ± 46.66 μmol/L (n = 98); Q2 group: 358.23 ± 14.03 μmol/L (n = 99); Q3 group: 405.50 ± 14.59 μmol/L (n = 98) and Q4 group: 499.14 ± 56.97μmol/L (n = 98). Renal outcome was defined by progression to end-stage renal disease (ESRD). Kaplan-Meier survival analysis and Cox proportional hazards model were used to analyze the association between SUA quartiles and the renal outcomes.

RESULTS

During the median 3-year follow-up period, there were 173 ESRD outcome events (44.02%). No significant difference between SUA level and the risk of progression of DN (P = 0.747) was shown in the Kaplan-Meier survival analysis. In multivariable-adjusted model, hazard ratios for developing ESRD were 1.364 (0.621-2.992; P = 0.439), 1.518 (0.768-3.002; P = 0.230) and 1.411 (0.706-2.821; P = 0.330) for the Q2, Q3 and Q4, respectively, in comparison with the Q1 (P = 0.652).

CONCLUSIONS

No significant association between SUA level and renal outcome of ESRD in Chinese patients with T2DM and DN was found in our study. Besides, the role of uric acid-lowering therapy in delaying DN progression and improving ESRD outcome had not yet been proven. Further study was needed to clarify the renal benefit of the uric acid-lowering therapy in the treatment of DN.

Serum Uric Acid Levels and Risk of Rapid Decline of Estimated Glomerular Filtration Rate in Patients with Type 2 Diabetes: Findings from a 5-Year Prospective Cohort Study

This study investigated the association between serum uric acid (SUA) levels with rapid decline of the estimated glomerular filtration rate (eGFR) in type 2 diabetes (T2 DM) patients. A prospective cohort study was conducted in a community-based hospital in Vietnam. We followed 405 T2DM patients with normal kidney function for five years. Rapid progression of kidney function was defined as an average annual decrease of eGFR of at least 4 mL/min/1.73 m² and was found in 16.0% of patients. Patients in the SUA high tertile ( ≥6 mg/dL) had higher BMI (p = 0.004), lower HbA1c (p = 0.001), lower eGFR (p < 0.001) and higher rate of hypertension than low and middle tertile. After adjusting for age and sex, rapid progression of renal function was significantly associated with SUA level (OR = 1.22, 95% CI 1.02-1.45, p = 0.026). This association was marginally significant when more covariates were included in the model (OR = 1.20, 95% CI 0.99-1.46, p = 0.065). However, the association between tertiles of SUA and rapid decline of eGFR was not statistically significant. This study demonstrates neither a strong significant association between SUA and rapid decline of eGFR nor evidence to refuse the role of SUA levels in the increased risk of renal function decline in in T2DM patients.

Diabetic kidney disease: new clinical and therapeutic issues. Joint position statement of the Italian Diabetes Society and the Italian Society of Nephrology on "The natural history of diabetic kidney disease and treatment of hyperglycemia in patients with type 2 diabetes and impaired renal function"

Aims

This joint document of the Italian Diabetes Society and the Italian Society of Nephrology reviews the natural history of diabetic kidney disease (DKD) in the light of the recent epidemiological literature and provides updated recommendations on anti-hyperglycemic treatment with non-insulin agents.

Data Synthesis

Recent epidemiological studies have disclosed a wide heterogeneity of DKD. In addition to the classical albuminuric phenotype, two new albuminuria-independent phenotypes have emerged, i.e., “nonalbuminuric renal impairment” and “progressive renal decline”, suggesting that DKD progression toward end-stage kidney disease (ESKD) may occur through two distinct pathways, albuminuric and nonalbuminuric. Several biomarkers have been associated with decline of estimated glomerular filtration rate (eGFR) independent of albuminuria and other clinical variables, thus possibly improving ESKD prediction. However, the pathogenesis and anatomical correlates of these phenotypes are still unclear. Also the management of hyperglycemia in patients with type 2 diabetes and impaired renal function has profoundly changed during the last two decades. New anti-hyperglycemic drugs, which do not cause hypoglycemia and weight gain and, in some cases, seem to provide cardiorenal protection, have become available for treatment of these individuals. In addition, the lowest eGFR safety thresholds for some of the old agents, particularly metformin and insulin secretagogues, have been reconsidered.

Conclusions

The heterogeneity in the clinical presentation and course of DKD has important implications for the diagnosis, prognosis, and possibly treatment of this complication. The therapeutic options for patients with type 2 diabetes and impaired renal function have substantially increased, thus allowing a better management of these individuals.

Clinical features of and risk factors for normoalbuminuric diabetic kidney disease in hospitalized patients with type 2 diabetes mellitus: a retrospective cross-sectional study

BACKGROUND

Normoalbuminuric diabetic kidney disease (NADKD) is a newly defined DKD, the clinical features and pathogenesis for which are still being understood. This study aimed to investigate the features and risk factors for NADKD in patients with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective cross-sectional study was conducted. The related clinical and laboratory data of patients with T2DM hospitalized between August 2012 and January 2020 were collected for statistical analysis. We classified the patients with T2DM into four groups on the basis of the presence or absence of albuminuria and reduced estimated glomerular filtration rate (eGFR). Analysis of variance, the Kruskal-Wallis test, and the chi-square test were used to compare the groups. Binary logistic regression analyses with a forward stepwise method were performed to explore the risk factors for renal dysfunction in hospitalized patients with normoalbuminuric T2DM.

RESULTS

Among the 1620 patients evaluated, 500 (30.9%) had DKD, of which 9% had NADKD. The prevalence of stroke, cardiovascular events, carotid plaque, and peripheral arterial disease in NADKD was significantly higher than in a non-DKD control group (normoalbuminuric T2DM patients with eGFR of ≥60 ml/min/1.73 m²). Regression analyses revealed that three significant independent factors were associated with NADKD: age (OR = 1.089, confidence interval [CI] 95% [1.055-1.123], p < 0.001), previous use of renin-angiotensin system inhibitors (RASIs; OR = 2.330, CI 95% [1.212-4.481], p = 0.011), and glycated hemoglobin (HbA1c; OR = 0.839, CI 95% [0.716-0.983], p = 0.03).

CONCLUSIONS

NADKD is mainly associated with macrovascular rather than microvascular complications. NADKD is more common in patients with normoalbuminuric T2DM with older age, previous use of RASIs, and good glycemic control.

The Pattern of Allopurinol Prescription Among Chronic Kidney Disease Patients in a Tertiary Care Centre: A Single-Centre Experience

Context

Hyperuricemia is prevalent in patients with chronic kidney disease (CKD). Although it is associated with CKD incidence and progression, treating asymptomatic hyperuricemia with uric acid-lowering agents is still debatable.

Aim of Work

determine the rate of non-classical prescription of allopurinol in CKD patients.

Settings and Design

This was a retrospective study of adult patients prescribed allopurinol with CKD (stages 2–5) in Doctor Soliman Fakeeh Hospital (DSFH) Jeddah, Saudi Arabia, from 1/1/2016 to 1/1/2017.

Subjects and Methods

Eligible patients were identified from the hospital’s pharmacy system and cross-referenced with the electronic health records. Demographic data, laboratory results and indication as recorded by the prescribing physician were extracted. Prescriptions with no indication were categorized based on the uric acid levels. Hyperuricemia was documented as mild (6–10 mg/dL in females and 7–13 mg/dL in males) and severe (>13mg/dL in men and >10mg/dL in women).

Statistical Analysis Used

Descriptive statistics (frequencies, percentages).

Results

From the 594 identified patients, 464 (78.1%) were males. A third of prescriptions (209/594) had no indication, 43.5% of which (91/209) had no documented uric acid levels, and 16.3% (34/209) had normal levels. Including patients with undocumented indication, 64.2% (381/594) were prescribed allopurinol for hyperuricemia, 86.4% of which (329/381) had mild hyperuricemia, and only 13.6% (52/381) had severe hyperuricemia. Other indications included malignancy-related disorders (6.2%, 37/594), gouty arthritis (5.2%, 31/594), and stones of unknown aetiology (3.4%, 20/594).

Conclusion

The percentage of allopurinol prescription to patients with CKD without a clear indication in our centre was markedly high. This might increase the risk for side effects with no evidence-based benefits.

The association between serum uric acid and diabetic complications in patients with type 2 diabetes mellitus by gender: a cross-sectional study

BACKGROUND

The relationship between serum uric acid (SUA) and several diabetic complications or co-morbidities remains a matter of debate. The study aims to explore the association between SUA levels and the prevalence of non-alcoholic fatty liver disease (NAFLD), diabetic retinopathy (DR), diabetic nephropathy (DN) and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 2,809 participants (1,784 males and 1,025 females) were included in this cross-sectional study. Clinical characteristics and the prevalence of each of the four diseases were analyzed based on gender-specific quartiles of SUA levels. The Pearson correlation analysis and linear-regression analysis were used to access the correlation between SUA levels and clinical characteristics. Furthermore, a binary logistic regression analysis was carried out to determine whether SUA was an independent risk factor for each of the four complications.

RESULTS

SUA levels were positively correlated to BMI, BUN, Scr and TG, but negatively associated with eGFR, HDL, FBG, 2h-PG and HbA1c% for the patients with T2DM. The prevalence of NAFLD and DN, but not DR or DPN, were increased with SUA levels from the first to the fourth quartile. Binary logistic regression further disclosed that SUA was an independent risk factor for NAFLD (ORs Male = 1.002, ∗ P = 0.0013; ORs Female = 1.002, ∗ P = 0.015) and DN (ORs Male = 1.006, ∗ P < 0.001; ORs Female = 1.005, ∗ P < 0.001), but not for DR and DPN. After adjustment for the confounders, SUA levels were significantly associated with NAFLD within the 3rd (ORs = 1.829, P = 0.004) and 4th quartile (ORs = 2.064, P = 0.001) for women, but not independently associated with SUA for man. On the other hand, our results revealed increased prevalence of DN for SUA quartile 2 (ORs = 3.643, P = 0.039), quartile 3 (ORs = 3.967, P = 0.024) and quartile 4 (ORs = 9.133, P < 0.001) in men; however, SUA quartiles were significantly associated with DN only for quartile 4 (ORs = 4.083, P = 0.042) in women.

CONCLUSION

For patients with T2DM, elevated SUA concentration is an independent risk factor for the prevalence of NAFLD and DN after adjustment for other indicators, but not DR or DPN.

Inter-relationship of risk factors and pathways associated with chronic kidney disease in patients with type 2 diabetes mellitus: a structural equation modelling analysis

OBJECTIVES

Diabetes mellitus is the most common cause of chronic kidney disease (CKD); however, the inter-relationships and pathogenetic mechanisms among risk factors are still largely unknown. Structural equation modelling (SEM) was applied to test a hypothesis of causal pathways related to CKD in patients with type 2 diabetes mellitus (T2DM).

STUDY DESIGN

This is a prospective observational study.

METHODS

A total of 3395 patients with T2DM were enrolled in this study. A hypothesised SEM was applied to assess associations among demographic data, diabetic self-management behaviours, diabetes control, lifestyle, psycho-social, chronic inflammation factors, anthropometric and metabolic variables simultaneously and the risk of CKD.

RESULTS

Demographic data (including education, marital status and mini-mental state examination score) (-0.075), white blood cell count (0.084), high blood pressure (0.144), World Health Organisation (WHO) 5 well-being index (-0.082), diabetes control (0.099), triglyceride (0.091) and uric acid (0.282) levels had direct effects on the risk of CKD. The final model could explain 26% of the variability in baseline CKD status. In addition, the same direct and specific indirect factors at baseline CKD status analysis contributed to the risk of CKD at the 12-month follow-up. The final model could explain 31% of the variability in the risk of CKD at the 12-month follow-up.

CONCLUSIONS

This study investigates associations between factors obtained from real-world daily practice and CKD status simultaneously and delineates the potential pathways and inter-relationships of the risk factors that contribute to the development of CKD in patients with T2DM.

Risk factors for subclinical renal damage and its progression: Hanzhong Adolescent Hypertension Study

BACKGROUND/OBJECTIVES

Chronic kidney disease (CKD) is a global public health problem, including in China. The aim of this study was to identify the risk factors for the development and progression of subclinical renal disease (SRD) in a Chinese population. We also examined whether the impact of the risk factors on SRD changed over time.

SUBJECTS/METHODS

To identify the predictors of SRD, we performed a cross-sectional study of the 2432 subjects in our Hanzhong Adolescent Hypertension Cohort. A subgroup of 202 subjects was further analyzed over a 12-year period from 2005 to 2017 to determine the risk factors for the development and progression of SRD.

RESULTS

In cross-sectional analysis, elevated blood pressure, male gender, diabetes, body mass index, and triglyceride were independently associated with a higher risk of SRD. In longitudinal analysis, an increase in total cholesterol over a 4-year period and an increase in serum triglyceride over a 12-year period were independently associated with progression of albuminuria. Finally, increases in both total cholesterol and serum uric acid over a 4-year follow-up showed an independent association with a modest reduction in estimated glomerular filtration rate (eGFR).

CONCLUSIONS

In this study of a Chinese cohort, we show several metabolic abnormalities as independent risk factors for subclinical renal disease in a Chinese cohort. In addition, we demonstrate that the effects of total cholesterol, triglycerides and uric acid on the development and progression of albuminuria or the decline in eGFR vary at different points of follow-up. These findings highlight the importance of early detection of metabolic abnormalities to prevent SRD.

A randomized controlled clinical trial study protocol of Liuwei Dihuang pills in the adjuvant treatment of diabetic kidney disease

INTRODUCTION

A large number of patients with diabetic kidney disease (DKD) approach traditional Chinese medicine (TCM) owing to discontent with standard treatments. Based on TCM theory and clinical experience, the syndrome of kidney yin deficiency is a common type of DKD. Liuwei Dihuang pills (LDPs) is a common prescription of a Chinese herbal formula for patients presenting this syndrome of DKD. However, well-established data supporting the efficacy and safety of LDP in DKD treatment are lacking.

METHODS

We have designed a double-blind, placebo-controlled, randomized trial. After a 2-week run-in period, 124 eligible participants with DKD will be assigned to either the experimental or the control group in a 1:1 ratio. Patients in the experimental group will receive LDP, while patients in the control group will receive a matched placebo. As the basic treatment in the 2 groups, metformin hydrochloride sustained-release tablets, for blood glucose control, and irbesartan tablets, for blood pressure regulation, will be provided. All participants will undergo 4 weeks of treatment and 12 weeks of follow-up. The primary outcome is the change in 24 hours urinary protein levels, measured from the baseline to the end of the treatment phase (week 24). The secondary outcomes to be assessed include the change in serum creatinine and estimated glomerular filtration rate, urinary albumin excretion rate, improvement of TCM syndromes and symptoms, fasting blood glucose and postprandial 2-hour blood glucose, blood lipids (total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol, from baseline to weeks 12 and 24.

DISCUSSION

The results of this study will provide high-quality evidence of the effects of LDP in DKD treatment, which will provide an alternative treatment strategy in patients with DKD.

Uric acid and risk of diabetic kidney disease

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD) in the Western world. Better control of glycemia and blood pressure, including renin-angiotensin system blockade (RASB), appear to have slowed DKD progression rate but have been unable to substantially decrease the annual incidence of new cases of DKD related ESKD. Thus, new treatment targets are needed. Higher levels of serum uric acid (SUA) have been associated with increased risk and progression of DKD in persons with types 1 (T1D) and 2 (T2D) diabetes and of chronic kidney disease (CKD) in general. This review presents the epidemiological, clinical, and clinical trial evidence regarding the hypothesis that SUA reduction could slow progression of DKD and/or CKD in general.

Common and Unique Factors and the Bidirectional Relationship Between Chronic Kidney Disease and Nonalcoholic Fatty Liver in Type 2 Diabetes Patients

PURPOSE

This study aimed to investigate the common and unique risk factors and bidirectional relationship between chronic kidney disease (CKD) and nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

This was a cross-sectional study of patients with T2DM enrolled in a disease management program at two specialized diabetes outpatient clinics. Common and unique risk factors for CKD and NAFLD were examined using structural equation models (SEMs). SEMs were also used to examine direct and indirect effects of NAFLD on CKD and those of CKD on NAFLD.

RESULTS

A total of 1992 subjects with T2DM were enrolled in this study. In multivariate analysis, NAFLD was independently associated with the odds of CKD (adjusted odds ratio=1.59, 95% confidence interval=1.12-2.25, P=0.009). SEMs showed that age, triglyceride, uric acid (UA), albumin, and HbA1c levels had statistically significant direct effects on CKD, and the final model could explain 22% of the variability in CKD. Age, triglycerides, body mass index (BMI), UA, white blood cell (WBC) count, serum glutamic pyruvic transaminase (SGPT) level, and smoking status had statistically significant direct effects on NAFLD, and the final model could explain 43% of the variability in NAFLD. The common risk factors contributing to both CKD and NAFLD were age, triglycerides, and UA. The unique risk factors were albumin and HbA1c for CKD, and BMI, WBC, SGPT, and smoking for NAFLD. In addition, SEM analysis also confirmed the bidirectional causal relationship between NAFLD and CKD.

CONCLUSION

Common and unique risk factors and a bidirectional relationship existed between CKD and NAFLD in our patients with T2DM.

Diabetic kidney disease: New clinical and therapeutic issues. Joint position statement of the Italian Diabetes Society and the Italian Society of Nephrology on "The natural history of diabetic kidney disease and treatment of hyperglycemia in patients with type 2 diabetes and impaired renal function"

AIMS

This joint document of the Italian Diabetes Society and the Italian Society of Nephrology reviews the natural history of diabetic kidney disease (DKD) in the light of the recent epidemiological literature and provides updated recommendations on anti-hyperglycemic treatment with non-insulin agents.

DATA SYNTHESIS

Recent epidemiological studies have disclosed a wide heterogeneity of DKD. In addition to the classical albuminuric phenotype, two new albuminuria-independent phenotypes have emerged, i.e., "nonalbuminuric renal impairment" and "progressive renal decline", suggesting that DKD progression toward end-stage kidney disease (ESKD) may occur through two distinct pathways, albuminuric and nonalbuminuric. Several biomarkers have been associated with decline of estimated glomerular filtration rate (eGFR) independent of albuminuria and other clinical variables, thus possibly improving ESKD prediction. However, the pathogenesis and anatomical correlates of these phenotypes are still unclear. Also the management of hyperglycemia in patients with type 2 diabetes and impaired renal function has profoundly changed during the last two decades. New anti-hyperglycemic drugs, which do not cause hypoglycemia and weight gain and, in some cases, seem to provide cardiorenal protection, have become available for treatment of these individuals. In addition, the lowest eGFR safety thresholds for some of the old agents, particularly metformin and insulin secretagogues, have been reconsidered.

CONCLUSIONS

The heterogeneity in the clinical presentation and course of DKD has important implications for the diagnosis, prognosis, and possibly treatment of this complication. The therapeutic options for patients with type 2 diabetes and impaired renal function have substantially increased, thus allowing a better management of these individuals.

Effects of Uric Acid on Diabetes Mellitus and Its Chronic Complications

With the deepening of the researches on uric acid, especially in the study of metabolic diseases, uric acid has been found to be closely related to obesity, metabolic syndrome, nonalcoholic fatty liver disease, diabetes, and other metabolic diseases. Uric acid causes a series of pathophysiological changes through inflammation, oxidative stress, vascular endothelial injury, and so on and thus subsequently promotes the occurrence and development of diseases. This review confirmed the positive correlation between uric acid and diabetes mellitus and its chronic complications through the pathogenesis and clinical studies aspects.

Threshold Effects of Serum Uric Acid on Chronic Kidney Disease in US Women without Hypertension and Diabetes: A Cross-Sectional Study

Background: Serum uric acid (SUA) has been associated with increased risk of chronic kidney disease (CKD) in observational studies; however, data in women without hypertension and diabetes are sparse. Purpose: To examine the association between SUA and CKD among women without hypertension and diabetes. Methods: In this cross-sectional study of 6,776 US women without hypertension and diabetes from the National Health and Nutrition Examination Survey (1999–2006), we investigated the relationship between SUA and CKD using multivariable logistic regression models. Moreover, a generalized additive model and smooth curve fitting (penalized spline method) and a 2 piecewise logistic regression models were conducted to address for nonlinearity. Results: The prevalence of CKD was 8.3%. Multiple logistic analyses showed that per 1 mg/dL increase in SUA was associated with 39% increased prevalence of CKD. Analyses using restricted cubic spline confirmed that the association between SUA and CKD was nonlinear. Further, threshold and saturation effect analysis showed that the inflection point of SUA was 4.5 mg/dL. The ORs (95% CIs) were 0.84 (0.66–1.08) on the left side of inflection point and 1.87 (1.56–2.24) on the right side of inflection point, respectively. Subgroup analysis showed that the stronger association between SUA and CKD was observed in elder women with never/former smoking and higher fasting blood glucose levels (all p values for interaction <0.05). Conclusion: Our study suggested threshold effects of SUA on the prevalence of CKD among US women without hypertension and diabetes. SUA levels >4.5 mg/dL were positively and independently associated with CKD.

Uric acid and the cardio-renal effects of SGLT2 inhibitors

Sodium/glucose co-transporter-2 (SGLT2) inhibitors, which lower blood glucose by increasing renal glucose elimination, have been shown to reduce the risk of adverse cardiovascular (CV) and renal events in type 2 diabetes. This has been ascribed, in part, to haemodynamic changes, body weight reduction and several possible effects on myocardial, endothelial and tubulo-glomerular functions, as well as to reduced glucotoxicity. This review evaluates evidence that an effect of SGLT2 inhibitors to lower uric acid may also contribute to reduced cardio-renal risk. Chronically elevated circulating uric acid concentrations are associated with increased risk of hypertension, CV disease and chronic kidney disease (CKD). The extent to which uric acid contributes to these conditions, either as a cause or an aggravating factor, remains unclear, but interventions that reduce urate production or increase urate excretion in hyperuricaemic patients have consistently improved cardio-renal prognoses. Uric acid concentrations are often elevated in type 2 diabetes, contributing to the "metabolic syndrome" of CV risk. Treating type 2 diabetes with an SGLT2 inhibitor increases uric acid excretion, reduces circulating uric acid and improves parameters of CV and renal function. This raises the possibility that the lowering of uric acid by SGLT2 inhibition may assist in reducing adverse CV events and slowing progression of CKD in type 2 diabetes. SGLT2 inhibition might also be useful in the treatment of gout and gouty arthritis, especially when co-existent with diabetes.

Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors: A Clinician's Guide

This comprehensive review covers the historical background, physiology, application in type 2 diabetes, novel uses, cardiovascular benefits, side effects and contraindications of sodium-glucose cotransporter-2 (SGLT2) inhibitors. SGLT2 inhibitors are an insulin-independent class of oral antihyperglycemic medication that clinicians use in the treatment of type 2 diabetes. Multiple landmark clinical trials support the effectiveness of SGLT2 inhibitors in reducing blood glucose levels, but it is important to understand when to properly utilize them. SGLT2 inhibitors are the most beneficial as an adjunct medication in addition to metformin in patients with a history of cardiovascular or renal disease who need further hemoglobin A1c reduction. The novel mechanism of action also demands clinicians be aware of the side effects not typically experienced with other oral antihyperglycemic drugs, such as genital tract infections, lower leg amputations, electrolyte disturbances and bone fractures. On top of their benefits in type 2 diabetes, novel uses for SGLT2 inhibitors are being uncovered. Diabetic patients with non-alcoholic fatty liver disease, who are at an increased risk of cirrhosis and hepatocellular carcinoma, experience a clinically significant reduction in serum alanine aminotransferase levels. SGLT2 inhibitors are also effective at lowering body weight in obese individuals and decreasing systolic blood pressure. Dual SGLT1/SGLT2 inhibitors are currently being investigated as possibly the first oral medication for type 1 diabetes.

Serum uric acid levels and decreased estimated glomerular filtration rate in patients with type 2 diabetes: A cohort study and meta-analysis

BACKGROUND

Epidemiological studies suggest that elevated serum uric acid (SUA) is associated with heightened incident kidney disease in both the general population and the type 2 diabetes (T2D) cases, although the results were not entirely consistent.

METHODS

We investigated prospective association between SUA levels and estimated glomerular filtration (eGFR) decline risk (eGFR <60 mL min^-1 1.73 m^-2 ) among 3123 T2D in the Dongfeng-Tongji cohort and further examined this association with a meta-analysis. Generalize linear model was used to assess the associations of SUA with eGFR decline in the cohort. In the meta-analysis, we used both fix-effects and random-effects models to calculate the overall effect estimate.

RESULTS

During 5-year follow-up, 303 (9.7%) patients developed eGFR decline. After multiple adjustments, the relative risk (RR) (95% CI) of eGFR decline was 1.55 (1.07, 2.26) when comparing the highest with the lowest sex-specific uric acid quartile. A 100 μmol/L increment of SUA level was significantly associated with 21% increased risk of eGFR decline. The SUA-eGFR decline association was more evident in men, but not in women. In meta-analysis, the pooled RR (95% CI) was 2.33 (1.66, 3.25) for developing eGFR decline when comparing the highest with the lowest levels of uric acid. A 100 μmol/L increment of SUA level was significantly associated with a 33% increased risk of eGFR decline.

CONCLUSIONS

Our results indicate an independent and significant positive association between higher SUA and increased risk of developing eGFR decline among T2D cases.

Elevated serum cytokeratin-18 concentration in patients with type 2 diabetes mellitus and non-alcoholic fatty liver disease

BACKGROUND

Serum cytokeratin-18 is believed to be a marker of hepatic cell damage. However, few studies have discussed about the serum cytokeratin-18 concentration in type 2 diabetes mellitus patients and investigated its association with non-alcoholic fatty liver disease as well as metabolic biomarkers.

METHODS

Healthy participants and type 2 diabetes mellitus patients were enrolled. Physical and metabolic factors were recorded, and non-alcoholic fatty liver disease was screened by abdominal ultrasound and the fatty liver index. The cytokeratin-18 concentration was detected using two commercially available immunoassay kits (M30 and M65 ELISA kit, Previa AB, Sweden).

RESULTS

Overall, 22.8% (29/127) and 35.9% (42/117) of the participants were diagnosed with non-alcoholic fatty liver disease in the non-diabetes mellitus group and type 2 diabetes mellitus group, respectively. In the non-diabetes mellitus group and type 2 diabetes mellitus group, our result showed that participants with non-alcoholic fatty liver disease had a higher serum cytokeratin-18 M30 and cytokeratin-18 M65 concentration as compared with participants without non-alcoholic fatty liver disease. Interestingly, as compared with healthy participants without non-alcoholic fatty liver disease, our result also demonstrated that type 2 diabetes mellitus patients without non-alcoholic fatty liver disease had a higher serum cytokeratin-18 M30 (108.4 ± 66.2 vs. 87.1 ± 34.6 U/L; P = 0.038) and cytokeratin-18 M65 concentration (285.4 ± 115.3 vs. 248.5 ± 111.3 U/L; P = 0.031). The independent relationship between type 2 diabetes mellitus and cytokeratin-18 was further strengthened by the significant positive association between fasting plasma glucose and serum cytokeratin-18 concentration via multivariate regression analyses (cytokeratin-18 M30: β = 0.034, P = 0.029; cytokeratin-18 M65: β = 0.044, P = 0.002).

CONCLUSIONS

Independent of non-alcoholic fatty liver disease, our results suggested that the cytokeratin-18 concentration is closely associated with the hyperglycaemic milieu. The association between serum cytokeratin-18 and type 2 diabetes mellitus may be worthy of further investigation.

Does Altered Uric Acid Metabolism Contribute to Diabetic Kidney Disease Pathophysiology?

PURPOSE OF REVIEW

Multiple experimental and clinical studies have identified pathways by which uric acid may facilitate the development and progression of chronic kidney disease (CKD) in people with diabetes. However, it remains uncertain if the association of uric acid with CKD represents a pathogenic effect or merely reflects renal impairment.

RECENT FINDINGS

In contrast to many published reports, a recent Mendelian randomization study did not identify a causal link between uric acid and CKD in people with type 1 diabetes. Two recent multicenter randomized control trials, Preventing Early Renal Function Loss in Diabetes (PERL) and FEbuxostat versus placebo rAndomized controlled Trial regarding reduced renal function in patients with Hyperuricemia complicated by chRonic kidney disease stage 3 (FEATHER), were recently designed to assess if uric acid lowering slows progression of CKD. We review the evidence supporting a role for uric acid in the pathogenesis of CKD in people with diabetes and the putative benefits of uric acid lowering.

Uric Acid and Diabetic Nephropathy Risk

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) in the western world. Current treatment methods, with better control of glycemia and blood pressure, including renin-angiotensin system blockade (RASB), appear to have slowed the DN progression rate but have not substantially decreased the annual incidence of new DN ESRD cases. Thus, new treatment targets are needed.

SUMMARY

Higher levels of serum uric acid (UA) are associated with increased risk of the clinical manifestations of DN in persons with types 1 and 2 diabetes. Also, UA is a strong predictor of DN progression. Two small, short-term, proof-of-concept clinical trials in which a minority of the patients had diabetes suggested that reduction of UA with allopurinol could decrease the rate of glomerular filtration rate (GFR) loss in persons with chronic kidney disease (CKD). However, a definitive trial to check whether UA reduction can benefit DN progression has not been conducted as yet. Preventing Early Renal Loss in Diabetes (PERL) is an ongoing trial in persons with type 1 diabetes and early to moderate GFR reduction. This 3-year randomized placebo controlled trial in 530 subjects is to check whether UA reduction with allopurinol can slow the rate of GFR decline as determined by the plasma disappearance of iohexol. Key Message: If the results of the PERL trial are positive, initiation of UA reduction treatment while GFR is relatively well preserved could delay ESRD in DN by 8-10 years, that is, considerably longer than the period that has been demonstrated for RASB. This could have important implications for the treatment of DN in particular and of CKD in general.

Red cell distribution width as a significant indicator of medication and prognosis in type 2 diabetic patients

Whether red cell distribution width (RDW) can be a potential indicator for diabetic nephropathy (DN) is unknown. A total of 809 type 2 diabetes mellitus (T2D) patients were divided into 4 groups according to the quartiles (Q) of the RDW (%): Q1 ≤ 12.4 (n = 229), 12.4 < Q2 ≤ 12.9 (n = 202), 12.9 < Q3 < 13.5 (n = 168), Q4 ≥ 13.5 (n = 210). Results showed that the levels in Q4 group was higher in age, disease duration, systolic blood pressure, blood urea nitrogen, creatinine, uric acid and proteinuria but lower in hemoglobin, serum albumin and glycosylated hemoglobin compared to Q1 group. Furthermore, the incidences of DN, diabetic peripheral neuropathy, hypertension and coronary heart disease in the Q3 or Q4 group were higher compared to Q1 group. Medications including calcium channel blockers and antiplatelet therapy also showed higher frequencies in Q3 or Q4 group compared to Q1. Logistic regression indicated that the antiplatelet therapy (OR = 2.065), hypertension (OR = 2.819), creatinine (OR = 4.473) and proteinuria (OR = 2.085) were positively associated with level of Q4 group, but higher hemoglobin (OR = 0.021) and serum Ca²⁺ (OR = 0.178) were negatively associated with Q4. This data suggest that high level of RDW in T2D patients indicates a higher risk and a poor prognosis for DN.

Renal function preservation with pioglitazone or with basal insulin as an add-on therapy for patients with type 2 diabetes mellitus

AIMS

Clinical outcome may differ owing to the distinct pharmacological characteristics of insulin sensitizers and insulin. This study was performed to compare the metabolic and renal function changes with add-on pioglitazone treatment versus basal insulin in patients with type 2 diabetes mellitus (DM) in whom sulfonylurea and metformin regimens failed.

METHODS

Patients who were consecutively managed in the diabetes comprehensive program with add-on pioglitazone or detemir/glargine treatment for at least 2 years following sulfonylurea and metformin treatment failure were included.

RESULTS

A total of 1002 patients were enrolled (pioglitazone: 559, detemir: 264, glargine: 179). After propensity score matching, there were 105 patients with matchable baseline characteristics in each group. After a mean of 3.5 years of follow-up, the pioglitazone group showed a greater HbA1c reduction than the detemir group and the glargine group. Despite patients in all three groups exhibiting significant body weight gain, those in the pioglitazone group and the glargine group showed greater body weight increases than the patients in the detemir group (2.1, 1.6 and 0.8 kg, respectively, p < 0.05). Interestingly, Cox regression analysis indicated that patients under detemir or glargine treatment had a higher probability of CKD progression as compared with the pioglitazone group, with hazard ratios of 2.63 (95% CI 1.79-3.88) and 3.13 (95% CI 2.01-4.87), respectively.

CONCLUSIONS

Our study first showed that treatment with both pioglitazone and basal insulin improved glycemic control, while only pioglitazone treatment was observed to be advantageous in terms of preserving renal function when used as an add-on therapy for patients with type 2 DM in whom sulfonylurea and metformin regimens failed.

Management of Gout and Hyperuricemia in CKD

Hyperuricemia and gout, the clinical manifestation of monosodium urate crystal deposition, are common in patients with chronic kidney disease (CKD). Although the presence of CKD poses additional challenges in gout management, effective urate lowering is possible for most patients with CKD. Initial doses of urate-lowering therapy are lower than in the non-CKD population, whereas incremental dose escalation is guided by regular monitoring of serum urate levels to reach the target level of <6mg/dL (or <5mg/dL for patients with tophi). Management of gout flares with presently available agents can be more challenging due to potential nephrotoxicity and/or contraindications in the setting of other common comorbid conditions. At present, asymptomatic hyperuricemia is not an indication for urate-lowering therapy, though emerging data may support a potential renoprotective effect.

Febuxostat Attenuates Renal Damage besides Exerting Hypouricemic Effect in Streptozotocin-Induced Diabetic Rats

Aim. In this study, we aimed to investigate the effects of febuxostat, a novel inhibitor of xanthine oxidase (XO), on renal damage in streptozotocin- (STZ-) induced diabetic rats. Methods. Diabetes was induced by the intraperitoneal injection of STZ in male Sprague-Dawley rats. Sham-injected rats served as controls. The control and diabetic rats were treated with and without febuxostat for 8 weeks, respectively. Fasting blood and 24-h urine samples were collected every 4 weeks. Rat livers were extracted for detecting gene expression, content, and bioactivity of XO. Results. Diabetic rats showed significantly increased serum uric acid (SUA), serum creatinine (SCr), and urea nitrogen (BUN) levels. Daily urinary albumin (UAE), uric acid (UUA), and creatinine (UCr) excretion were also significantly increased in these rats. In diabetic rats, at week 8, febuxostat decreased SUA by 18.9%, while UAA was increased by 52.0%. However, UCr and urinary urea nitrogen (UUN) levels remained unchanged, while SCr and BUN levels decreased by >30% in these rats. Although hepatic gene expression, content, and activity of XO increased significantly in diabetic rats, febuxostat only slightly decreased its content. Conclusions. Febuxostat significantly attenuated renal damage in STZ-induced diabetic rats in addition to exerting hypouricemic effect.

Association Between Uric Acid and Renal Hemodynamics: Pathophysiological Implications for Renal Damage in Hypertensive Patients

The role of vascular renal changes in mediating the association between serum uric acid (SUA) and renal damage is unclear. The purposes of this study were to investigate the relationship between SUA and renal resistive index (RRI), assessed by duplex Doppler ultrasonography, and to assess whether hemodynamic renal changes may explain the association between SUA and renal damage in hypertensive patients. A total of 530 hypertensive patients with and without chronic kidney disease were enrolled and divided into SUA tertiles based on sex-specific cutoff values. RRI and albuminuria were greater and glomerular filtration rate (GFR) was lower in the uppermost SUA tertile patients when compared with those in the lowest tertiles (all P<.001). Moreover, SUA strongly correlated with RRI (P<.001) in all patients. However, RRI did not seem to explain the relationship between SUA and renal damage, and GFR significantly related with SUA in the overall population (P<.001) even after adjustment for RRI.