Clinical features and long-term outcomes of diabetic kidney disease - A prospective cohort study from China

Supplemented Gegen Qinlian Decoction Formula attenuates podocyte mitochondrial fission and renal fibrosis in diabetic kidney disease by inhibiting TNF-α-mediated necroptosis, compared with empagliflozin

ETHNOPHARMACOLOGICAL RELEVANCE

Recently, podocyte mitochondrial dysfunction and necroptosis have been shown to play critical roles in renal fibrosis (RF) in diabetic kidney disease (DKD); however, these conditions lack effective treatment. In China, the supplemented Gegen Qinlian Decoction Formula (SGQDF), which originates from the classical prescription Gegen Qinlian Decoction, has been widely used to treat patients with DKD. However, it remains unclear whether SGQDF alleviates podocyte injury-associated RF in patients with DKD.

AIM OF STUDY

This study aimed to clarify the therapeutic effects of SGQDF compared with those of empagliflozin (EMPA) on podocyte mitochondrial fission and RF in DKD and its necroptosis-related mechanisms.

MATERIALS AND METHODS

Modified DKD rat models were developed through a combination of uninephrectomy, streptozotocin administration through intraperitoneal injection, and exposure to a high-fat diet. Following RF formation, the DKD rat models received either a high dose of SGQDF (H-SGQDF), a low dose of SGQDF (L-SGQDF), EMPA, or vehicle for 4 weeks. In our in vitro study, we subjected cultured murine podocytes to a high-glucose environment and various treatments including Mdivi-1, adalimumab, and necrostatin-1, with or without H-SGQDF or EMPA. SGQDF target prediction and molecular docking verification were performed. For the in vivo study, we focused on examining changes in the parameters associated with renal injury, RF, and oxidative stress (OS)-induced injuries in podocytes. Both in vivo and in vitro studies included an analysis of changes in podocyte mitochondrial fission, TNF-α-induced podocyte necroptosis, and the RIPK1/RIPK3/MLKL signaling pathway activation.

RESULTS

SGQDF improved renal injury markers, including body weight, blood glucose, serum creatinine, blood urea nitrogen, and urinary albumin, in a dose-dependent manner. The beneficial effects of H-SGQDF in vivo were greater than those of L-SGQDF alone in vivo. Interestingly, similar to EMPA, H-SGQDF ameliorated RF and reduced OS-induced podocyte injury in diabetic kidneys. Furthermore, TNF-α signaling was shown to be important in the network construction of "the SGQDF-component-target." Based on this, we also showed that the beneficial effects in vivo and in vitro of H-SGQDF were closely related to the improvement in mitochondrial dysfunction and the inhibition of TNF-α-induced necroptosis in podocytes.

CONCLUSION

In the present study, we showed that H-SGQDF, similar to EMPA, attenuates podocyte mitochondrial fission and RF, and that the underlying therapeutic mechanisms are closely related to inhibiting the activation of the RIPK1/RIPK3/MLKL signaling axis in diabetic kidneys. Our findings provide new pharmacological evidence for the application of H-SGQDF in the RF treatment of DKD.

The effect of arteriosclerosis on new-onset renal damage in diabetic patients

The aim of this study was to investigate the effect of arteriosclerosis on new-onset renal damage in a Chinese community population with diabetes. Patients with diabetes who had attended at least one physical examination after the Brachial-ankle pulse wave velocity (BaPWV) test from 2010 to 2018 were selected as subjects. A total of 4,462 patients were included in the study cohort. BaPWV levels <1,400 cm/s, 1,400-1,799 cm/s, and ≥1,800 cm/s were applied to divide the subjects into a normal arterial stiffness group, borderline atherosclerosis group and atherosclerosis group. Renal damage was defined by isolated proteinuria, isolated eGFR <60 mL/min/1.73 m², proteinuria and eGFR <60 mL/min/1.73 m². A Cox proportional risk model was used to analyze the effect of different groups on new-onset renal damage. After a median follow-up of 2.85 (1.88-4.90) years, Cox proportional risk models showed that after adjusting for risk factors, compared with the normal group, the HR and 95% CI of the risk of new-onset renal damage were 1.29 (95% CI: 0.95-1.76) and 1.59 (95% CI: 1.14-2.22) in the borderline atherosclerosis group and the atherosclerosis group, respectively. Atherosclerosis is a risk factor for new-onset renal damage, especially new-onset proteinuria, in diabetic patients.

The Relationship between Vascular Aging Phenotypes and Renal Damage among Individuals with Type 2 Diabetes

OBJECTIVE

The aim of this study was to investigate the relationship between vascular aging (VA) phenotypes and renal damage in type 2 diabetic population.

METHODS

In this cross-sectional study, we included 8,141 individuals with type 2 diabetes who participated in the Kailuan Study during 2010-2018 and completed the brachial-ankle pulse wave velocity (baPWV) assessment for arterial stiffness, an indicator for VA. The age- and sex-specific 10th and 90th percentiles of baPWV based on a reference cohort were used as cutoffs to define supernormal VA (SUPERNOVA, baPWV<10th percentiles), normal VA (NVA, baPWV 10th to 90th percentiles), and early VA (EVA, baPWV>90th percentiles). The estimated glomerular filtration rate (eGFR) and proteinuria levels were used to assess renal damage, including isolated proteinuria, isolated kidney function decline (eGFR<60 mL/min/1.73 m2), and proteinuria combined with kidney function decline. Multivariable logistic regression analysis was used to analyze the relationship between VA phenotypes and diabetic kidney damage.

RESULTS

The prevalences of isolated proteinuria, isolated kidney function decline, and proteinuria combined with kidney function decline were 17.0%, 12.2%, and 5.4%, respectively. Compared with NVA, SUPERNOVA was associated with 34% lower odds (95% confidence interval [CI]: 0.46-0.96) of isolated proteinuria after adjusting for age, sex, and other potential confounders. EVA was associated with higher odds of all three types of kidney damage; the adjusted odds ratio (95% CI) was 1.42 (1.20-1.67) for proteinuria, 1.24 (1.01-1.51) for kidney function decline, and 1.56 (1.18-2.06) for proteinuria combined with kidney function decline.

CONCLUSIONS

VA phenotypes are associated with renal damage, especially isolated proteinuria. SUPERNOVA was associated with lower odds of isolated proteinuria and EVA was associated with higher odds of proteinuria and kidney function decline.

Comparison of Nonalbuminuric and Albuminuric Diabetic Kidney Disease Among Patients With Type 2 Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND

Diabetic kidney disease (DKD) is one of most common complications of diabetes. Recently, the classical phenotype of DKD, which is characterized by albuminuria preceding renal insufficiency, has been challenged since a subset of diabetic patients with renal insufficiency but without albuminuria has been increasingly reported. However, the available evidence is inconsistent. Thus, the present systematic review will assess and summarize the available data regarding nonalbuminuric diabetic kidney disease (NADKD).

METHODS

PubMed, Embase, and Cochrane were searched for clinical trials related to NADKD. The results were limited to full-text articles published in English, without restrictions on the publication time. The quality of clinical trials was appraised, and the data were extracted. Meta-analysis was conducted using a random-effects model. Descriptive analysis was performed if the data were insufficient.

RESULTS

A final total of 31 articles were included in this review. The meta-analysis of 18 studies showed that compared with albuminuric DKD, patients with NADKD were older (MD = 1.04 years old, 95% CI [0.52, 1.57], p < 0.05); were more often women (Male RR = 0.74, 95% CI [0.68, 0.81], p < 0.05); had shorter diabetes duration (MD = -2.9 years, 95% CI [-3.63, -2.18], p < 0.05), lower HbA1c levels (MD = -0.34%, 95% CI [-0.42, -0.25], p < 0.05), and lower blood pressure (systolic blood pressure MD = -6.21 mmHg, 95% CI [-9.41, -3.0], p < 0.05; diastolic blood pressure MD = -1.27 mmHg, 95% CI [-2.15, 4.0], p < 0.05); less frequently experienced diabetic retinopathy (RR = 0.58, 95% CI [0.51, 0.67], p < 0.05); and less frequently used renin-angiotensin-aldosterone system (RAAS) inhibitors. The underlying pathology of NADKD might be different from that of the classic phenotype of DKD, which is associated with more advanced tubulointerstitial and vascular lesions but mild typical glomerular lesions. The annual estimated glomerular filtration rate decline tended to be lower in patients with NADKD than in those with albuminuric DKD. The risk for cardiovascular disease, end-stage renal disease, and all-cause death was lower for patients with NADKD than patients with albuminuric DKD.

CONCLUSIONS

The prevalence of NADKD has increased in recent decades, and its characteristics, pathology, and prognosis are different from those of albuminuric DKD; thus, diagnosis and treatment strategies should be different. More attention should be given to this phenotype.

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.

Bayesian Age-Period-Cohort Prediction of Mortality of Type 2 Diabetic Kidney Disease in China: A Modeling Study

Background

The burden of type 2 diabetic kidney disease (DKD) continues to rise in China. We analyzed time trends in DKD mortality and associations with age, period, and birth cohort from 1990 to 2019, made projections up to 2030, and examined the drivers of deaths from DKD.

Methods and Findings

The number of DKD deaths in China from 1990 to 2019 was obtained from the GBD 2019. We used age-period-cohort modeling to estimate age, period, and cohort effects in DKD mortality between 1990 and 2019. We calculated net drift (overall annual percentage change), local drift (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rates), period, and cohort relative risks. We used Bayesian age-period-cohort analysis with integrated nested Laplace approximations to project future age-specific DKD death cases from 2020 to 2030. We used a validated decomposition algorithm to attribute changes in DKD deaths to population growth, population aging, and epidemiologic changes from 1990 to 2030. From 1990 to 2019, the age-standardized mortality rate of DKD in China was relatively stable, but the absolute number of DKD deaths showed a noticeable increasing trend. The overall annual percentage change (net drift) was -0.75% (95% confidence interval, CI: -0.93 to -0.57) for males and -1.90% (95% CI, -2.19 to -1.62) for females. The age-specific annual percentage changes (local drifts) were below zero in all age groups from 1990 to 2019 except for males aged above 65 to 69 years, and for females aged above 70 to 74 years. The risk of DKD deaths increased exponentially with age for both sexes after controlling for period deviations. The Bayesian age-period-cohort analysis projects that there would be 88,803 deaths from DKD in 2030, increased by 224.2% from 1990. Despite a decrease in age-specific DKD death rates, the reduction would be entirely offset by population aging.

Conclusions

Although China has made progress in reducing DKD deaths, demographic changes have entirely offset the progress. The burden of DKD deaths is likely to continue increasing. Our findings suggest that large-scale screening is imperative for DKD control and prevention, particularly for high-risk groups.

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.

Changing epidemiology of chronic kidney disease as a result of type 2 diabetes mellitus from 1990 to 2017: Estimates from Global Burden of Disease 2017

AIMS/INTRODUCTION

Type 2 diabetes mellitus has been a leading cause of chronic kidney disease (CKD), with a heterogeneous distribution worldwide. Optimal healthcare planning requires an understanding of how the burden of CKD as a result of type 2 diabetes mellitus has changed over time and geographic location, as well as the potential roles of sociodemographic, clinical and behavioral factors in these changes.

MATERIALS AND METHODS

We used the Global Burden of Disease data from 1990 to 2017 at the global, regional and national levels to investigate changes in the incidence, death and disability-adjusted life years of CKD as a result of type 2 diabetes mellitus, incorporating both epidemiological research and risk factor monitoring.

RESULTS

The incident cases of CKD as a result of type 2 diabetes mellitus worldwide in 2017 had increased by 74% compared with 1990; total disability-adjusted life years had increased by 113%, mainly attributable to population expansion and demographic transition. The Sociodemographic Index was significantly and negatively correlated with overall CKD as a result of type 2 diabetes mellitus burden. However, in 82 countries and territories, the burden was not alleviated in parallel with socioeconomic development.

CONCLUSIONS

CKD as a result of type 2 diabetes mellitus has been the main contributor to the increasing burden of CKD over the past several decades. We suggest a more pragmatic approach focusing on early diagnosis, primary care and adequate follow up to reduce mortality and the long-term burden in low-to-middle Sociodemographic Index regions. Interventions should address high systolic blood pressure, as well as overweight and obesity problems, especially in high-income regions.

Update on diagnosis, pathophysiology, and management of diabetic kidney disease

Diabetic kidney disease (DKD) is a chronic complication of diabetes mellitus which may eventually lead to end-stage kidney disease (ESKD). Despite improvements in glycaemic control and blood pressure management with renin-angiotensin-aldosterone system (RAAS) blockade, the current therapy cannot completely halt DKD progression to ESKD in some patients. DKD is a heterogeneous disease entity in terms of its clinical manifestations, histopathology and the rate of progression, which makes it difficult to develop effective therapeutics. It was formerly considered that albuminuria preceded kidney function decline in DKD, but recent epidemiological studies revealed that a distinct group of patients presented kidney dysfunction without developing albuminuria. Other comorbidities, such as hypertension, obesity and gout, also affect the clinical course of DKD. The pathophysiology of DKD is complex and multifactorial, involving both metabolic and haemodynamic factors. These induce activation of intracellular signalling pathways, oxidative stress, hypoxia, dysregulated autophagy and epigenetic changes, which result in kidney inflammation and fibrosis. Recently, two groups of antidiabetic drugs, sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists, were demonstrated to provide renoprotection on top of their glucose-lowering effects. Several other therapeutic agents are also being developed and evaluated in clinical trials.

Oral candidiasis and denture stomatitis in diabetic patients: Systematic review and meta-analysis

Here, the prevalence of oral candidiasis and denture stomatitis among diabetic patients compared to healthy ones was summarized through a systematic review with meta-analysis. Medline, Scopus, Web of Science, Lilacs, Cochrane Library, Embase, and the grey literature were searched without restriction, until May 2020. Eligibility criteria were established, data were extracted, and quality assessment was conducted by two trained examiners. Qualitative synthesis was based on the recommendations of Fowkes and Fulton. Two meta-analyses were performed on studies investigating patients with: a) oral candidiasis and b) denture stomatitis. Out of 6034 screened studies, seven were eligible for qualitative and quantitative synthesis; of these, three evaluated oral candidiasis and four evaluated denture stomatitis. Qualitative synthesis showed that the main methodological problems of the studies included sample size, source of controls, matching, and randomization. Diabetic patients had a similar chance of developing oral candidiasis to non-diabetic patients (OR1.40 [0.96; 2.04], p = 0.08, I2 = 94%). However, diabetic patients had a higher chance to present denture stomatitis compared to non-diabetic patients (OR 1.92 [1.42, 2.59] p < 0.0001, I2 = 0%). Therefore, diabetic patients have a higher chance of developing denture stomatitis compared to non-diabetic patients. However, for all analyses, the certainty of the evidence was considered to be very low.

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.