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"

Machine learning-based risk predictive models for diabetic kidney disease in type 2 diabetes mellitus patients: a systematic review and meta-analysis

Background

Machine learning (ML) models are being increasingly employed to predict the risk of developing and progressing diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM). However, the performance of these models still varies, which limits their widespread adoption and practical application. Therefore, we conducted a systematic review and meta-analysis to summarize and evaluate the performance and clinical applicability of these risk predictive models and to identify key research gaps.

Methods

We conducted a systematic review and meta-analysis to compare the performance of ML predictive models. We searched PubMed, Embase, the Cochrane Library, and Web of Science for English-language studies using ML algorithms to predict the risk of DKD in patients with T2DM, covering the period from database inception to April 18, 2024. The primary performance metric for the models was the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI). The risk of bias was assessed using the Prediction Model Risk of Bias Assessment Tool (PROBAST) checklist.

Results

26 studies that met the eligibility criteria were included into the meta-analysis. 25 studies performed internal validation, but only 8 studies conducted external validation. A total of 94 ML models were developed, with 81 models evaluated in the internal validation sets and 13 in the external validation sets. The pooled AUC was 0.839 (95% CI 0.787-0.890) in the internal validation and 0.830 (95% CI 0.784-0.877) in the external validation sets. Subgroup analysis based on the type of ML showed that the pooled AUC for traditional regression ML was 0.797 (95% CI 0.777-0.816), for ML was 0.811 (95% CI 0.785-0.836), and for deep learning was 0.863 (95% CI 0.825-0.900). A total of 26 ML models were included, and the AUCs of models that were used three or more times were pooled. Among them, the random forest (RF) models demonstrated the best performance with a pooled AUC of 0.848 (95% CI 0.785-0.911).

Conclusion

This meta-analysis demonstrates that ML exhibit high performance in predicting DKD risk in T2DM patients. However, challenges related to data bias during model development and validation still need to be addressed. Future research should focus on enhancing data transparency and standardization, as well as validating these models' generalizability through multicenter studies.

Systematic Review Registration

https://inplasy.com/inplasy-2024-9-0038/, identifier INPLASY202490038.

Preclinical Detection of Early Glomerular Injury in Children with Kidney Diseases-Independently of Usual Markers of Kidney Impairment and Inflammation

Glomerular kidney diseases typically begin insidiously and can progress to end stage kidney failure. Early onset of therapy can slow down disease progression. Early diagnosis is required to ensure such timely therapy. The goal of our study was to evaluate protein biomarkers (BMs) for common nephropathies that have been described for children with Alport syndrome. Nineteen candidate BMs were determined by commercial ELISA in children with congenital anomalies of the kidneys and urogenital tract, inflammatory kidney injury, or diabetes mellitus. It is particularly essential to search for kidney disease BMs in children because they are a crucial target group that likely exhibits early disease stages and in which misleading diseases unrelated to the kidney are rare. Only minor differences in blood between affected individuals and controls were found. However, in urine, several biomarker candidates alone or in combination seemed to be promising indicators of renal injury in early disease stages. The BMs of highest sensitivity and specificity were collagen type XIII, hyaluronan-binding protein 2, and complement C4-binding protein. These proteins are unrelated to inflammation markers or to risk factors for and signs of renal failure. In conclusion, our study evaluated several strong candidates for screening for early stages of kidney diseases and can help to establish early nephroprotective regimens.

Association between continuous glucose monitoring-derived glycemic control indices and urinary biomarkers of diabetic kidney disease: Hyogo Diabetes Hypoglycemia Cognition Complications study

AIMS

Glomerular damage and proximal tubular damage play an important role in the pathogenesis of diabetic kidney disease. This study aimed to investigate the relationship between the urinary markers of proximal tubular injury, including urinary liver-type fatty acid-binding protein-to-creatinine ratio (uL-FABP/Cr) and urinary N-acetyl-β-D-glucosaminidase-to-creatinine ratio (uNAG/Cr), and glycemic control status.

METHODS

This cross-sectional study included 245 and 39 patients with type 2 diabetes mellitus (T2DM) and non-T2DM (NDM), respectively. The participants of this study were fitted with retrospective CGM, and glycemic control indices, such as time in range (TIR) and glycemia risk index (GRI), were calculated.

RESULTS

The results were presented as medians (interquartile ranges). The uL-FABP/Cr was significantly higher in the microalbuminuria than in the normo-albuminuria group [4.2 (2.7-7.1) and 2.2 (1.4-3.4) μg/gCr, respectively, P < 0.001], while the uNAG/Cr in the normo-albuminuria group [6.3 (4.5-10.1) U/gCr] was significantly higher than that in the NDM group [5.3 (3.8-6.3) U/gCr, P = 0.048] but significantly lower than that in the microalbuminuria group [9.2 (6.4-11.1) U/gCr, P = 0.004]. The multivariate logistic regression analysis indicated that CGM-derived TIR was significantly associated with the urinary albumin-to-creatinine ratio [uAlb/Cr, odds ratio (OR) 0.985, 95% confidence interval (CI) 0.971-0.998, P = 0.029] and uNAG/Cr (OR 0.973, 95% CI 0.957-0.989, P = 0.001) independent of renal function. GRI was similarly associated with uAlb/Cr and uNAG/Cr.

CONCLUSION

The findings of this study indicated that uNAG/Cr was elevated before albuminuria development and was associated with CGM-derived TIR and GRI.

Microwave-assisted synthesis of Limonia acidissima Groff gum stabilized palladium nanoparticles for colorimetric glucose sensing

Herein, we present a novel microwave-assisted method for the synthesis of palladium nanoparticles (PdNPs) supported by Limonia acidissima Groff tree extract gum. The synthesized PdNPs were characterized using various analytical techniques, including FTIR, SEM, TEM, UV-visible, and powder XRD analyses. TEM and XRD analysis confirmed that the synthesized LAG-PdNPs are highly crystalline nature spherical shapes with an average size diameter of 7-9 nm. We employed these gum-capped PdNPs to investigate their peroxidase-like activity for colorimetric detection of hydrogen peroxide (H2O2) and glucose. The oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2, catalyzed by PdNPs, produces oxidation products quantified at 652 nm using spectrophotometry. The catalytic activity of PdNPs was optimized with respect to temperature and pH. The developed method exhibited a linear range of detection from 1 to 50 µm, with detection limits of 0.35 µm for H2O2 and 0.60 µm for glucose.

Mechanistic role of Syzygium cumini (L.) Skeels in glycation induced diabetic nephropathy via RAGE-NF-κB pathway and extracellular proteins modifications: A molecular approach

ETHNOPHARMACOLOGY RELEVANCE

Syzygium cumini (L.) Skeels (SC), an ancient medicinal plant, is used as a complementary and alternative medicine for treating diabetes mellitus and its associated complications, such as diabetic nephropathy (DN). Phytochemicals present in SC homeopathic formulations possess anti-glycemic, anti-glycation, anti-inflammatory, and antioxidant properties. Additionally, the non-enzymatic formation of advanced glycation end products (AGEs) increases during hyperglycemia in diabetes. AGEs interaction with their receptor of AGEs (RAGE) promotes inflammation via Nuclear Factor-κB (NF-κB) and the accumulation of Extracellular Matrix (ECM) proteins, contributing to the renal dysfunction in DN. However, the molecular mechanism through which SC formulations interact with the AGEs-RAGE-NF-κB pathway has not yet been investigated.

AIM

This study aims to examine the impact of SC formulations on the RAGE-NF-κB pathway and ECM protein modifications in glycation-induced DN using a molecular approach.

MATERIALS AND METHODS

Human serum albumin (10 mg/ml) was glycated with MGO (55 mM) in the presence of SC formulations - Mother tincture (MT), 30C, 200C for 7 days. Glycated samples were added to renal cells (HEK 293) for 24 h. Subsequently, cellular gene and protein expressions of RAGE, NF-κB, vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), collagen IV (Col IV), and fibronectin were determined using RT-qPCR and Western blot analysis. The immunofluorescence, luciferase assay, and chromatin immunoprecipitation techniques were employed to gain insights into glycation-induced NF-κB nuclear translocation, transcriptional activity, and its effect on RAGE promoter activity in SC-treated cells.

RESULTS

SC formulations significantly downregulated glycation-induced elevated levels of RAGE and NF-κB. Mechanistically, SC formulations prevented NF-κB nuclear translocation, transcriptional activity, and RAGE promoter activity. Also, SC formulations significantly attenuated glycation-enhanced expressions of inflammatory cytokines (IL-6, TNF-α, and VEGF) and ECM proteins (Col IV and fibronectin).

CONCLUSION

Our findings enlighten the molecular mechanism of SC in DN by targeting the AGEs-RAGE-NF-κB signaling pathway, inflammatory responses, and ECM accumulation. Hence, the study validates the protective role of SC formulations and signifies its novel potential for treating DN.

Current updates on metabolites and its interlinked pathways as biomarkers for diabetic kidney disease: A systematic review

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes mellitus (DM) that poses a serious risk as it can lead to end-stage renal disease (ESRD). DKD is linked to changes in the diversity, composition, and functionality of the microbiota present in the gastrointestinal tract. The interplay between the gut microbiota and the host organism is primarily facilitated by metabolites generated by microbial metabolic processes from both dietary substrates and endogenous host compounds. The production of numerous metabolites by the gut microbiota is a crucial factor in the pathogenesis of DKD. However, a comprehensive understanding of the precise mechanisms by which gut microbiota and its metabolites contribute to the onset and progression of DKD remains incomplete. This review will provide a summary of the current scenario of metabolites in DKD and the impact of these metabolites on DKD progression. We will discuss in detail the primary and gut-derived metabolites in DKD, and the mechanisms of the metabolites involved in DKD progression. Further, we will address the importance of metabolomics in helping identify potential DKD markers. Furthermore, the possible therapeutic interventions and research gaps will be highlighted.

The Role of Selenium Nanoparticles in Addressing Diabetic Complications: A Comprehensive Study

Diabetes, as an emerging epidemic, has put forward a significant spotlight on the evolving population worldwide grounded upon the remarkable affliction of healthcare along with economical conflict. Various studies suggested that, in modern society, lack of maintenance of a healthy life style leads to the occurrence of diabetes as insulin resistant, later having a damaging effect on the pancreatic β-cells, suggesting various complications. Furthermore, diabetes management is controversial owing to different opinions based on the prevention of complications. For this purpose, nanostructured materials (NSM) like selenium nanoparticles (SeNPs) have proved their efficiency in the therapeutic management of such serious diseases. This review offers an in- -depth idea regarding the pathophysiology, diagnosis and various conventional therapeutics of type 1 and type 2 diabetes, shedding light on Diabetic Nephropathy (DN), a case study of type 1 diabetes. Moreover, this review provides an exhaustive study by highlighting the economic and healthcare burdens associated with diabetes along with the controversies associated with conventional therapeutic management and the promising role of NSM like selenium nanoparticles (SeNPs), as a novel weapon for encountering such fatal diseases.

Histological findings of diabetic kidneys transplanted in non-diabetic recipients: a case series

BACKGROUND

Diabetic donors are recognized as a reliable source of organs, although the discard rate of kidneys is still high. Few data are available on the histological evolution of these organs especially on kidneys transplanted into non-diabetic patients who remain euglycemic.

METHODS

We describe the histological evolution of ten kidney biopsies performed on non-diabetic recipients of diabetic donors.

RESULTS

Mean donor age was 69 ± 7 years, 60% were males. Two donors were treated with insulin, eight with oral antidiabetic drugs. Mean recipient age was 59.9 ± 7 years, 70% were males. The pre-existing diabetic lesions identified in the pre-implantation biopsies, encompassed all histological classes, and were associated with mild IF/TA and vascular damages. The median follow-up was 59.5 [IQR 32.5-99.0] months; at follow-up, 40% of cases did not change histologic classification, two patients with class IIb downgraded to IIa or I and one with class III downgraded to IIb. Conversely, three cases showed a worsening, from class 0 to I, I to IIb or from IIa to IIb. We also observed a moderate evolution of IF/TA and vascular damages. At follow-up visit, estimated GFR was stable (50.7 mL/min vs. 54.8 at baseline) and proteinuria was mild (51.1 ± 78.6 mg/day).

CONCLUSIONS

Kidneys from diabetic donors show variable evolution of the histologic features of diabetic nephropathy after transplant. This variability may be associated to recipients characteristics such as euglycemic milieu, in case of improvement, or obesity and hypertension, in case of worsening of histologic lesions.

Magnetic Resonance Imaging in Clinical Trials of Diabetic Kidney Disease

Chronic kidney disease (CKD) associated with diabetes mellitus (DM) (known as diabetic kidney disease, DKD) is a serious and growing healthcare problem worldwide. In DM patients, DKD is generally diagnosed based on the presence of albuminuria and a reduced glomerular filtration rate. Diagnosis rarely includes an invasive kidney biopsy, although DKD has some characteristic histological features, and kidney fibrosis and nephron loss cause disease progression that eventually ends in kidney failure. Alternative sensitive and reliable non-invasive biomarkers are needed for DKD (and CKD in general) to improve timely diagnosis and aid disease monitoring without the need for a kidney biopsy. Such biomarkers may also serve as endpoints in clinical trials of new treatments. Non-invasive magnetic resonance imaging (MRI), particularly multiparametric MRI, may achieve these goals. In this article, we review emerging data on MRI techniques and their scientific, clinical, and economic value in DKD/CKD for diagnosis, assessment of disease pathogenesis and progression, and as potential biomarkers for clinical trial use that may also increase our understanding of the efficacy and mode(s) of action of potential DKD therapeutic interventions. We also consider how multi-site MRI studies are conducted and the challenges that should be addressed to increase wider application of MRI in DKD.

The function, mechanisms, and clinical applications of metformin: potential drug, unlimited potentials

Metformin has been used clinically for more than 60 years. As time goes by, more and more miraculous effects of metformin beyond the clinic have been discovered and discussed. In addition to the clinically approved hypoglycemic effect, it also has a positive metabolic regulation effect on the human body that cannot be ignored. Such as anti-cancer, anti-aging, brain repair, cardiovascular protection, gastrointestinal regulation, hair growth and inhibition of thyroid nodules, and other nonclinical effects. Metformin affects almost the entire body in the situation taking it over a long period, and the preventive effects of metformin in addition to treating diabetes are also beginning to be recommended in some guidelines. This review is mainly composed of four parts: the development history of metformin, the progress of clinical efficacy, the nonclinical efficacy of metformin, and the consideration and prospect of its application.

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.

Type 2 diabetes albuminuric and non-albuminuric phenotypes have different morphological and functional ultrasound features of diabetic kidney disease

AIMS

Whether different diabetic kidney disease (DKD) phenotypes recognise differences in morphological and vascular properties of the kidney is still unexplored. We evaluated the potential role of kidney ultrasonography in differentiating DKD phenotypes in subjects with type 2 diabetes.

MATERIALS AND METHODS

This is a cross-sectional, single-centre study. Total (TRV) and parenchymal renal volumes (PRV) were calculated by applying the ellipsoid formula for conventional (2D) ultrasonography and with manual segmentation for 3D ultrasonography, and then adjusted for body surface area (aTRV, aPRV). Renal resistive index (RI) was contextually determined. DKD phenotypes have been defined based on increased urinary albumin-to-creatinine ratio (ACR >30 mg/g) and/or reduced eGFR (<60 ml/min/1.73 m² ). Recruitment was planned to have groups of the same size.

RESULTS

Among 256 subjects, 26.2% had No-DKD, 24.6% increased albuminuria only (Alb⁺ ), 24.2% non-albuminuric DKD (Alb^- DKD), and 25.0% albuminuric DKD (Alb⁺ DKD). Compared to No-DKD, RI was significantly higher in all DKD phenotypes, being the highest in Alb⁺ DKD, and with a significant trend of RI > 0.70 to increase across phenotypes. In comparison with No-DKD, both 2D and 3D volumes were increased in Alb⁺ and significantly reduced in Alb^- DKD as well as in Alb⁺ DKD, with significantly lower volumes in Alb^- DKD as compared to Alb⁺ DKD at the same reduced levels of eGFR. In adjusted regressions, compared to No-DKD, RI was associated with Alb⁺ ; both RI and aPRV3D were associated with Alb⁺ DKD; only aPRV3D with Alb^- DKD. Compared to No-DKD, Receiver Operating Characteristic curve analyses, designed taking into account conventional risk factors, showed that US parameters did not ameliorate the characterisation of Alb⁺ and Alb⁺ DKD, while aPRV3D significantly improved the phenotyping of Alb^- DKD.

CONCLUSIONS

As a novel information, we reported that, in type 2 diabetes, the emerging normoalbuminuric DKD phenotype showed reduced TRVs and PRVs even when compared, at similarly reduced eGFR levels, with Alb⁺ DKD opening. In perspective, these findings suggest a possible role of imaging for better discrimination of DKD phenotypes in clinical practice.

Nephroprotective Effects of Dapagliflozin in Patients with Type 2 Diabetes

Objective This study analyzed changes in the estimated glomerular filtration rate calculated using cystatin C (eGFRcys) and sodium excretion in the urine after administering dapagliflozin as an add-on therapy to conventional treatment for diabetes. Methods This was a single-center, single-group, prospective interventional study. Dapagliflozin was administered to improve the plasma glucose control in 30 subjects with type 2 diabetes mellitus (age 53±8 years old; 66.6% men). Blood and urine tests were performed before and 6 and 12 months after dapagliflozin administration. The daily sodium excretion was estimated with the Kawasaki formula using second-morning urine samples. Results The eGFRcys did not markedly differ before and 6 months after the dapagliflozin administration but was significantly increased after 12 months (p<0.001), and the estimated daily sodium excretion was also significantly increased (p<0.001 at 6 months and p=0.002 at 12 months). The systolic and diastolic blood pressures tended to decrease after administration. The HbA1c level after the administration of dapagliflozin tended to be lower in the T3 group, showing the smallest increase in changes in the estimated daily sodium excretion from baseline to 6 months (28.2-107.5 mEq/day), than in the combined groups of T1 (219.5-110.1 mEq/day) and T2 (101.4-28.9 mEq/day). In contrast, the eGFRcys was significantly higher in the combined groups of T1 and T2 than that in the T3 group at both 6 and 12 months (p=0.031 and p=0.007, respectively). Conclusions Add-on therapy with dapagliflozin increased the urinary sodium excretion and decreased the blood pressure even in the early phase of this therapy. Our results suggest that dapagliflozin add-on therapy may exert nephroprotective effects in subjects with type 2 diabetes mellitus.

Ameliorative Effects of a Rhenium (V) Compound with Uracil-Derived Ligand Markers Associated with Hyperglycaemia-Induced Renal Dysfunction in Diet-Induced Prediabetic Rats

Kidney disease is characterised by the improper functioning of the kidney as a result of kidney damage caused by hyperglycaemia-induced oxidative stress. The moderate hyperglycaemia seen in prediabetes can be treated using a combination of metformin and lifestyle interventions (low-calorie diets and exercising). However, patients have been reported to over-rely on pharmacological interventions, thus decreasing the efficacy of metformin, which leads to the development of type 2 diabetes mellitus (T2DM). In this study, we investigated the effects of a rhenium (V) compound in ameliorating renal dysfunction in both the presence and absence of dietary modification. Kidney function parameters, such as fluid intake and urine output, glomerular filtration rate (GFR), kidney injury molecule (KIM 1), creatinine, urea, albumin and electrolytes, were measured after 12 weeks of treatment. After treatment with the rhenium (V) compound, kidney function was restored, as evidenced by increased GRF and reduced KIM 1, podocin and aldosterone. The rhenium (V) compound ameliorated kidney function by preventing hyperglycaemia-induced oxidative stress in the kidney in both the presence and absence of dietary modification.

Prevalence and Risk Factors of Abnormal Glucose Metabolism and New-Onset Diabetes Mellitus after Kidney Transplantation: A Single-Center Retrospective Observational Cohort Study

Background and objectives: New-onset diabetes after transplantation (NODAT) represents a primary cause of morbidity and allograft loss. We assessed prevalence and risk factors for NODAT in a population of Italian kidney transplant (KT) recipients. Methods: Data from 522 KT performed between January 2004 and December 2014 were analyzed. Participants underwent clinical examination; blood and urine laboratory tests were obtained at baseline, one, six, and 12-month of follow-up to detect glucose homeostasis abnormalities and associated metabolic disorders. An oral glucose tolerance test (OGTT) was performed at six months in 303 subjects. Results: Most patients were Caucasian (82.4%) with a mean age of 48 ± 12 years. The prevalence of abnormal glucose metabolism (AGM) and NODAT was 12.6% and 10.7%, respectively. Comparing characteristics of patients with normal glucose metabolism (NGM) to those with NODAT, we found a significant difference in living donation (16.6% vs. 6.1%; p = 0.03) and age at transplant (46 ± 12 vs. 56 ± 9 years; p = 0.0001). Also, we observed that patients developing NODAT had received higher cumulative steroid doses (1-month: 1165 ± 593 mg vs. 904 ± 427 mg; p = 0.002; 6-month:2194 ± 1159 mg vs. 1940 ± 744 mg; p = 0.002). The NODAT group showed inferior allograft function compared to patients with NGM (1-year eGFR: 50.1 ± 16.5 vs. 57 ± 20 mL/min/1.73 m2; p = 0.02). NODAT patients were more likely to exhibit elevated systolic blood pressure and higher total cholesterol and triglyceride levels than controls. Conclusions: The prevalence of NODAT in our cohort was relatively high. Patient age and early post-transplant events such as steroid abuse are associated with NODAT development.

Upregulation of miR145 and miR126 in EVs from Renal Cells Undergoing EMT and Urine of Diabetic Nephropathy Patients

Diabetic nephropathy (DN) is a severe kidney-related complication of type 1 and type 2 diabetes and the most frequent cause of end-stage kidney disease. Extracellular vesicles (EVs) present in the urine mainly derive from the cells of the nephron, thus representing an interesting tool mirroring the kidney's physiological state. In search of the biomarkers of disease progression, we here assessed a panel of urinary EV miRNAs previously related to DN in type 2 diabetic patients stratified based on proteinuria levels. We found that during DN progression, miR145 and miR126 specifically increased in urinary EVs from diabetic patients together with albuminuria. In vitro, miRNA modulation was assessed in a model of TGF-β1-induced glomerular damage within a three-dimensional perfusion system, as well as in a model of tubular damage induced by albumin and glucose overload. Both renal tubular cells and podocytes undergoing epithelial to mesenchymal transition released EVs containing increased miR145 and miR126 levels. At the same time, miR126 levels were reduced in EVs released by glomerular endothelial cells. This work highlights a modulation of miR126 and miR145 during the progression of kidney damage in diabetes as biomarkers of epithelial to mesenchymal transition.

Analysis of Expression of Diabetic Nephropathy-Related Protein and Stem Cell Tissue Repair Under Nano Membrane Concentration Technology

This study aimed to study protein expression in diabetic nephropathy (DN) rats and stem cell tissue repair based on nanomembrane concentration technology. Based on the polymer porous self-assembled nanomembrane technology, the content of total protein and albumin in the serum of rats in the control and experimental groups were measured. The obtained images were adopted to analyze the expression of cytoplasmic proteins and membrane proteins, and then the mechanism of stem cell tissue repair function was studied. The results showed that at 56 weeks of age, in contrast to control group, the total protein content in the serum of the experimental group evidently decreased. At 36 weeks of age, the cytoplasmic protein samples of diabetic rats in the experimental group were subjected to three two-dimensional protein electrophoresis. It was found that there were about 701 spots in each gel, and the matching rate was about 87.5%. In contrast to control group, 16 cytoplasmic proteins and 23 membrane proteins of the experimental group changed. The results of the differentially expressed protein analysis indicated that the change trends of protein spots. Based on polymer porous self-assembled nano-film technology, the expression of differential proteins in DN rats was analyzed, which would supplement new research assistance to the mechanism of DN.

Recent Advances in the Emerging Therapeutic Strategies for Diabetic Kidney Diseases

Diabetic kidney disease (DKD) is one of the most common causes of end-stage renal disease worldwide. The treatment of DKD is strongly associated with clinical outcomes in patients with diabetes mellitus. Traditional therapeutic strategies focus on the control of major risk factors, such as blood glucose, blood lipids, and blood pressure. Renin–angiotensin–aldosterone system inhibitors have been the main therapeutic measures in the past, but the emergence of sodium–glucose cotransporter 2 inhibitors, incretin mimetics, and endothelin-1 receptor antagonists has provided more options for the management of DKD. Simultaneously, with advances in research on the pathogenesis of DKD, some new therapies targeting renal inflammation, fibrosis, and oxidative stress have gradually entered clinical application. In addition, some recently discovered therapeutic targets and signaling pathways, mainly in preclinical and early clinical trial stages, are expected to provide benefits for patients with DKD in the future. This review summarizes the traditional treatments and emerging management options for DKD, demonstrating recent advances in the therapeutic strategies for DKD.

Interaction between Plasma Metabolomics and Intestinal Microbiome in db/db Mouse, an Animal Model for Study of Type 2 Diabetes and Diabetic Kidney Disease

Evidence has demonstrated that either metabolites or intestinal microbiota are involved in the pathogenesis of type 2 diabetes (T2D) and diabetic kidney disease (DKD). To explore the interaction between plasma metabolomics and intestinal microbiome in the progress of T2D-DKD, in the current study, we analyzed metabolomics in the plasma of db/db mice with liquid chromatography–mass spectrometry and also examined intestinal prokaryotes and entire gut microbiome dysbiosis at the genus level with both 16S rDNA and metagenomic sequencing techniques. We found that Negativibacillus and Rikenella were upregulated, while Akkermansia, Candidatus, Erysipelatoclostridium and Ileibacterium were downregulated in the colon of db/db mice compared with non-diabetic controls. In parallel, a total of 91 metabolites were upregulated, while 23 were downregulated in the plasma of db/db mice. The top five upregulated metabolites included D-arabinose 5-phosphate, estrone 3-sulfate, L-theanine, 3′-aenylic acid and adenosine 5′-monophosphate, and the five most significantly downregulated metabolites were aurohyocholic acid sodium salt, calcium phosphorylcholine chloride, tauro-alpha-muricholic acid sodium salt, galactinol and phosphocholine. These plasma metabolites were interacted with intestinal microbiomes, which are mainly involved in the pathways related to the biosynthesis of unsaturated fatty acids, fatty acid elongation, steroid biosynthesis, and D-arginine and D-ornithine metabolism. In the differential metabolites, N-acetyl-L-ornithine, ornithine and L-kyn could be metabolized by the correspondingly differential ontology genes in the intestinal metagenome. The current study thereby provides evidence for a gut–metabolism–kidney axis in the metabolism of db/db mice, in which the gut microbiome and circulating metabolomics interact, and suggests that information from this axis may contribute to our understanding of T2D and DKD pathogenesis.

Six-Month Periodic Fasting in Patients With Type 2 Diabetes and Diabetic Nephropathy: A Proof-of-Concept Study

CONTEXT

Novel fasting interventions have gained scientific and public attention. Periodic fasting has emerged as a dietary modification promoting beneficial effects on metabolic syndrome.

OBJECTIVE

Assess whether periodic fasting reduces albuminuria and activates nephropathy-driven pathways.

DESIGN/PARTICIPANTS

Proof-of-concept study where individuals with type 2 diabetes (n = 40) and increased albumin-to-creatinine ratio (ACR) were randomly assigned to receive a monthly fasting-mimicking diet (FMD) or a Mediterranean diet for 6 months with 3-month follow-up.

MAIN OUTCOMES MEASURES

Change in ACR was assessed by analysis of covariance adjusted for age, sex, weight loss, and baseline value. Prespecified subgroup analysis for patients with micro- vs macroalbuminuria at baseline was performed. Change in homeostatic model assessment for insulin resistance (HOMA-IR), circulating markers of dicarbonyl detoxification (methylglyoxal-derived hydroimidazolone 1, glyoxalase-1, and hydroxyacetone), DNA-damage/repair (phosphorylated histone H2AX), lipid oxidation (acylcarnitines), and senescence (soluble urokinase plasminogen activator receptor) were assessed as exploratory endpoints.

RESULTS

FMD was well tolerated with 71% to 95% of the participants reporting no adverse effects. After 6 months, change in ACR was comparable between study groups [110.3 (99.2, 121.5) mg/g; P = 0.45]. FMD led to a reduction of ACR in patients with microalbuminuria levels at baseline [-30.3 (-35.7, -24.9) mg/g; P ≤ 0.05] but not in those with macroalbuminuria [434.0 (404.7, 463.4) mg/g; P = 0.23]. FMD reduced HOMA-IR [-3.8 (-5.6, -2.0); P ≤ 0.05] and soluble urokinase plasminogen activator receptor [-156.6 (-172.9, -140.4) pg/mL; P ≤ 0.05], while no change was observed in markers of dicarbonyl detoxification or DNA-damage/repair. Change in acylcarnitines was related to patient responsiveness to ACR improvement. At follow-up only HOMA-IR reduction [-1.9 (-3.7, -0.1), P ≤ 0.05]) was sustained.

CONCLUSIONS

Improvement of microalbuminuria and of markers of insulin resistance, lipid oxidation, and senescence suggest the potential beneficial effects of periodic fasting in type 2 diabetes.

Der hepatogene Diabetes – aktueller Stand der Diagnostik und Therapie

Hintergrund

Patienten mit Leberzirrhose entwickeln häufig Störungen des Glukosemetabolismus wie Glukoseintoleranz oder einen hepatogenen Diabetes, welche neben der hepatozellulären Funktionseinschränkung durch die ausgeprägte Insulinresistenz als Folge der chronischen Lebererkrankung verursacht sind.

Diskussion

Empfehlungen mit Leitliniencharakter zur Diagnostik und Therapie des hepatogenen Diabetes fehlen bislang. Im Hinblick auf basistherapeutische Maßnahmen sollte eine ausreichende Deckung des Energie- und Proteinstoffwechsels gewährleistet sein, da ein Großteil der Zirrhosepatienten mangelernährt ist. Bei der medikamentösen Behandlung des hepatogenen Diabetes muss auf die erhöhte Hypoglykämiegefährdung geachtet werden. Aufgrund der Nebenwirkungen sind Biguanide sowie PPAR-gamma-Liganden bei Leberzirrhose kontraindiziert. Geeignete orale Antidiabetika sind insbesondere Sulfonylharnstoffanaloga und kurz wirksame Sulfonylharnstoffe. Wenn eine suffiziente Diabeteseinstellung mit oralen Antidiabetika nicht gelingt, sollte eine prandiale Insulintherapie mit Insulinen von kurzer Wirkdauer oder kurz wirksamen Insulinanaloga eingesetzt werden.

Schlussfolgerung

Die Optimierung einer diabetischen Stoffwechsellage hat neben der Vermeidung typischer diabetischer Spätkomplikationen eine wichtige Bedeutung für die Vermeidung und Reduzierung von Zirrhose-assoziierten Komplikationen wie z. B. gastrointestinalen Blutungsereignissen, hepatischer Enzephalopathie oder dem Auftreten eines hepatozellulären Karzinoms.

Genetic and Biological Effects of SLC12A3, a Sodium-Chloride Cotransporter, in Gitelman Syndrome and Diabetic Kidney Disease

The SLC12A3 (Solute carrier family 12 member 3) gene encodes a sodium-chloride cotransporter and mediates Na+ and Cl− reabsorption in the distal convoluted tubule of kidneys. An experimental study has previously showed that with knockdown of zebrafish ortholog, slc12a3 led to structural abnormality of kidney pronephric distal duct at 1-cell stage, suggesting that SLC12A3 may have genetic effects in renal disorders. Many clinical reports have demonstrated that the function-loss mutations in the SLC12A3 gene, mainly including Thr60Met, Asp486Asn, Gly741Arg, Leu859Pro, Arg861Cys, Arg913Gln, Arg928Cys and Cys994Tyr, play the pathogenic effects in Gitelman syndrome. This kidney disease is inherited as an autosomal recessive trait. In addition, several population genetic association studies have indicated that the single nucleotide variant Arg913Gln in the SLC12A3 gene is associated with diabetic kidney disease in type 2 diabetes subjects. In this review, we first summarized bioinformatics of the SLC12A3 gene and its genetic variation. We then described the different genetic and biological effects of SLC12A3 in Gitelman syndrome and diabetic kidney disease. We also discussed about further genetic and biological analyses of SLC12A3 as pharmacokinetic targets of diuretics.

AGEomics Biomarkers and Machine Learning-Realizing the Potential of Protein Glycation in Clinical Diagnostics

Protein damage by glycation, oxidation and nitration is a continuous process in the physiological system caused by reactive metabolites associated with dicarbonyl stress, oxidative stress and nitrative stress, respectively. The term AGEomics is defined as multiplexed quantitation of spontaneous modification of proteins damage and other usually low-level modifications associated with a change of structure and function—for example, citrullination and transglutamination. The method of quantitation is stable isotopic dilution analysis liquid chromatography—tandem mass spectrometry (LC-MS/MS). This provides robust quantitation of normal and damaged or modified amino acids concurrently. AGEomics biomarkers have been used in diagnostic algorithms using machine learning methods. In this review, I describe the utility of AGEomics biomarkers and provide evidence why these are close to the phenotype of a condition or disease compared to other metabolites and metabolomic approaches and how to train and test algorithms for clinical diagnostic and screening applications with high accuracy, sensitivity and specificity using machine learning approaches.

The Association Between Dietary Diversity Score and Odds of Diabetic Nephropathy: A Case-Control Study

A dietary diversity score (DDS) may be a useful strategy for monitoring risks associated with chronic diseases. Few studies have investigated the relationship between DDS and the progression to chronic kidney disease (CKD). A better understanding of the relationship between DDS and diabetic nephropathy (DN) may provide insight for monitoring the overall diet and clinical outcomes. This case-control study included 105 women with DN and 105 controls with age and diabetes duration-matched to evaluate the extent to which DDS is associated with DN. Dietary intake was assessed using the food frequency questionnaire (FFQ). DDS was calculated based on the method using five food groups: bread/grains, vegetables, fruits, meats, and dairies. Conditional logistic regression was performed to examine the association between DDS and odds of DN. Anthropometric measures and physical activity levels were evaluated using standard protocols. In a fully adjusted model [controlled for age, body mass index (BMI), energy intake, physical activity, diabetes duration, cardiovascular disease history, and drug usage], greater adherence (the third vs. the first tertile) to DDS [odds ratio (OR) = 0.13; 95% CI (0.05–0.35)], vegetables group [OR = 0.09; 95% CI (0.02–0.36)], and fruits group [OR = 0.05; 95% CI (0.01–0.20)] were significantly associated with lower odds of DN. However, we did not observe any significant relationship between other DDS components and the odds of DN. Our findings showed that higher DDS might be associated with reduced odds of DN. However, more prospective studies are warranted to confirm these findings.

Glomerular hyperfiltration

Circulating blood is filtered across the glomerular barrier to form an ultrafiltrate of plasma in the Bowman's space. The volume of glomerular filtration adjusted by time is defined as the glomerular filtration rate (GFR), and the total GFR is the sum of all single-nephron GFRs. Thus, when the single-nephron GFR is increased in the context of a normal number of functioning nephrons, single glomerular hyperfiltration results in 'absolute' hyperfiltration in the kidney. 'Absolute' hyperfiltration can occur in healthy people after high protein intake, during pregnancy and in patients with diabetes, obesity or autosomal-dominant polycystic kidney disease. When the number of functioning nephrons is reduced, single-nephron glomerular hyperfiltration can result in a GFR that is within or below the normal range. This 'relative' hyperfiltration can occur in patients with a congenitally reduced nephron number or with an acquired reduction in nephron mass consequent to surgery or kidney disease. Improved understanding of the mechanisms that underlie 'absolute' and 'relative' glomerular hyperfiltration in different clinical settings, and of whether and how the single-nephron haemodynamic and related biomechanical forces that underlie glomerular hyperfiltration promote glomerular injury, will pave the way toward the development of novel therapeutic interventions that attenuate glomerular hyperfiltration and potentially prevent or limit consequent progressive kidney injury and loss of function.

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.

Glomerular resistances predict long-term GFR decline in type 2 diabetic patients without overt nephropathy: a longitudinal subgroup analysis of the DEMAND trial

AIMS

Investigating whether and to what extent changes in glomerular hemodynamic parameters, beyond glomerular hyperfiltration, could predict glomerular filtration rate (GFR) decline in hypertensive, non-proteinuric type 2 diabetic patients.

MATERIALS AND METHODS

We estimated baseline afferent (Ra) and efferent (Re) arteriolar resistances and glomerular hydrostatic pressure in 60 consecutive patients from DEMAND study, using the Gomez' equations. Baseline renal plasma flow was measured by para-aminohippurate plasma clearance, and GFR was measured by iohexol plasma clearance at baseline and every 6 months for a median of 4.0 years [IQR 3.5-4.0 years]. Patients with a GFR decline > or ≤ 3 mL/min/1.73 m²/year were categorized as "Progressors" and "Non-progressors," respectively. Predictors of GFR decline were studied by univariable and multivariable logistic regression analysis.

RESULTS

•The GFR declined by a median [IQR] of 4.06 [5.46-2.00] mL/min/1.73 m²/year in the study group as a whole and by 5.35 [6.60-4.48] mL/min/1.73 m²/year and 1.71 [2.14-1.33] mL/min/1.73 m²/year in Progressors and Non-progressors, considered separately. Progressors had a higher baseline Ra (3487.3 ± 1349.3 dyne•sec•cm^-5 vs. 2877.0 ± 668.9 dyne•sec•cm^-5, p < 0.05) and higher Ra/Re ratio (1.4 ± 0.5 vs. 1.1 ± 0.3, p < 0.01) than Non-progressors. At multivariable logistic regression analysis, Ra/Re ratio and arterial hypertension duration were independently associated with GFR decline (odds ratio [95% CI] 8.50 [1.56-46.28] and 1.14 [1.01-1.28]), respectively.

CONCLUSIONS

Increased Ra/Re ratio and arterial hypertension duration predict early GFR decline in hypertensive non-proteinuric type 2 diabetic patients. These findings could be explained by glomerular hypoperfusion and chronic ischemic injury related to pre-glomerular arteriolar narrowing.

CLINICAL TRIAL REGISTRATION

DEMAND, NCT00157586, September 12, 2005.

Clinical implications of diabetes in chronic liver disease: Diagnosis, outcomes and management, current and future perspectives

Diabetes mellitus (DM) is common in liver cirrhosis (LC). The pathophysiological association is bidirectional. DM is a risk factor of LC and LC is a diabetogenic condition. In the recent years, research on different aspects of the association DM and LC has been intensified. Nevertheless, it has been insufficient and still exist many gaps. The aims of this review are: (1) To discuss the latest understandings of the association of DM and LC in order to identify the strategies of early diagnosis; (2) To evaluate the impact of DM on outcomes of LC patients; and (3) To select the most adequate management benefiting the two conditions. Literature searches were conducted using PubMed, Ovid and Scopus engines for DM and LC, diagnosis, outcomes and management. The authors also provided insight from their own published experience. Based on the published studies, two types of DM associated with LC have emerged: Type 2 DM (T2DM) and hepatogenous diabetes (HD). High-quality evidences have determined that T2DM or HD significantly increase complications and death pre and post-liver transplantation. HD has been poorly studied and has not been recognized as a complication of LC. The management of DM in LC patients continues to be difficult and should be based on drug pharmacokinetics and the degree of liver failure. In conclusion, the clinical impact of DM in outcomes of LC patients has been the most studied item recently. Nevertheless many gaps still exist particularly in the management. These most important gaps were highlighted in order to propose future lines for research.

Multiparametric Magnetic Resonance Imaging Allows Non-Invasive Functional and Structural Evaluation of Diabetic Kidney Disease

Background

We sought to develop a novel non-contrast multiparametric MRI (mpMRI) protocol employing several complementary techniques in a single scan session for a comprehensive functional and structural evaluation of diabetic kidney disease (DKD).

Methods

In the cross-sectional part of this prospective observational study, 38 subjects ages 18‒79 years with type 2 diabetes and DKD [estimated glomerular filtration rate (eGFR) 15‒60 mL/min/1.73 m²] and 20 age- and gender-matched healthy volunteers (HVs) underwent mpMRI. Repeat mpMRI was performed on 23 DKD subjects and 10 HVs. By measured GFR (mGFR), 2 DKD subjects had GFR stage G2, 16 stage G3 and 20 stage G4/G5. A wide range of MRI biomarkers associated with kidney haemodynamics, oxygenation and macro/microstructure were evaluated. Their optimal sensitivity, specificity and repeatability to differentiate diabetic versus healthy kidneys and categorize various stages of disease as well as their correlation with mGFR/albuminuria was assessed.

Results

Several MRI biomarkers differentiated diabetic from healthy kidneys and distinct GFR stages (G3 versus G4/G5); mean arterial flow (MAF) was the strongest predictor (sensitivity 0.94 and 1.0, specificity 1.00 and 0.69; P = .04 and .004, respectively). Parameters significantly correlating with mGFR were specific measures of kidney haemodynamics, oxygenation, microstructure and macrostructure, with MAF being the strongest univariate predictor (r = 0.92; P < .0001).

Conclusions

A comprehensive and repeatable non-contrast mpMRI protocol was developed that, as a single, non-invasive tool, allows functional and structural assessment of DKD, which has the potential to provide valuable insights into underlying pathophysiology, disease progression and analysis of efficacy/mode of action of therapeutic interventions in DKD.

Kidney outcomes and all-cause mortality in people with type 2 diabetes exhibiting non-albuminuric kidney insufficiency

AIM/HYPOTHESIS

It remains unclear whether people with diabetes exhibiting non-albuminuric kidney insufficiency have higher risk of kidney function decline and mortality compared with those exhibiting preserved kidney function without albuminuria. Furthermore, information regarding the incidence of albuminuria in people with this unique phenotype is sparse. Here, we aimed to elucidate the risk of the kidney outcomes and all-cause mortality in people with diabetes exhibiting non-albuminuric kidney insufficiency.

METHODS

In this retrospective cohort study, 8320 Japanese adults with type 2 diabetes were classified into four groups based on the presence of albuminuria and kidney insufficiency at baseline, defined as urinary albumin/creatinine ratio of equal to or above 30 mg/g and eGFR of less than 60 ml min^-1 1.73 m^-2, respectively. The primary composite kidney endpoint was a 50% decrease in eGFR from baseline or the initiation of kidney replacement therapy. The annual percentage change in eGFR slope and progression of albuminuria category were evaluated as the secondary and tertiary kidney endpoints, respectively. All-cause death was also set as the endpoint.

RESULTS

Compared with people exhibiting non-albuminuric preserved kidney function, those with non-albuminuric kidney insufficiency had the higher risk for the primary kidney endpoint (HR 4.1; 95% CI 2.5, 6.7; p < 0.001), steep percentage change in eGFR slope (-1.96%/year vs -1.36%/year, p < 0.001), incidence of albuminuria (HR 2.1; 1.7, 2.6; p < 0.001) and all-cause mortality (HR 1.5; 1.2, 2.0; p = 0.003). In the sensitivity analyses treating the incidence of albuminuria as a competing risk, people with non-albuminuric kidney insufficiency still had higher risk for the primary kidney endpoint and all-cause mortality than those with non-albuminuric preserved kidney function (subdistribution HR 2.8; 1.4, 5.6; p = 0.004; and 1.6; 1.1, 2.2; p = 0.014, respectively).

CONCLUSIONS/INTERPRETATION

People with type 2 diabetes exhibiting non-albuminuric kidney insufficiency had poorer kidney outcomes and life prognosis than those exhibiting non-albuminuric preserved kidney function.

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.

Re-thinking diabetic nephropathy: Microalbuminuria is just a piece of the diagnostic puzzle

The decline of the estimated glomerular filtration rate (eGFR) and the presence of albuminuria are the typical hallmarks of kidney disease arising as one of the most frequent diabetic complications over a long period of time, generally known as diabetic nephropathy or diabetes kidney disease (DKD). However, a decline in the renal function may occur in diabetic patients for other reasons unrelated to glycemic control, and this condition is known as non-diabetic kidney disease (NDKD). In this opinion paper we will review these conditions, and we outline the importance of other investigations, such as kidney biopsy and the measurement of novel biomarkers, in order to identify the disease progression early, and to allow a timely intervention. We will also focus on the actual limits of the quantitative measurements of albumin in urine, especially with regards to potential interferences due to the treatment of patients with statins.

Mitochondria in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end stage renal disease (ESRD) in the USA. The pathogenesis of DKD is multifactorial and involves activation of multiple signaling pathways with merging outcomes including thickening of the basement membrane, podocyte loss, mesangial expansion, tubular atrophy, and interstitial inflammation and fibrosis. The glomerulo-tubular balance and tubule-glomerular feedback support an increased glomerular filtration and tubular reabsorption, with the latter relying heavily on ATP and increasing the energy demand. There is evidence that alterations in mitochondrial bioenergetics in kidney cells lead to these pathologic changes and contribute to the progression of DKD towards ESRD. This review will focus on the dialogue between alterations in bioenergetics in glomerular and tubular cells and its role in the development of DKD. Alterations in energy substrate selection, electron transport chain, ATP generation, oxidative stress, redox status, protein posttranslational modifications, mitochondrial dynamics, and quality control will be discussed. Understanding the role of bioenergetics in the progression of diabetic DKD may provide novel therapeutic approaches to delay its progression to ESRD.

Neutrophil-lymphocyte ratio and platelet-lymphocyte ratio as novel risk markers for diabetic nephropathy in patients with type 2 diabetes

Introduction

Diabetes mellitus causes serious complications such as diabetic nephropathy. Diabetic nephropathy is now the most common reason of chronic kidney disease. Inflammation plays a crucial role in development and progression of diabetic nephropathy. The aim of this study was to evaluate the relationship of Inflammatory markers (neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio) with diabetic nephropathy in Syrian patients.

Materials and methods

A total of 158 patients with type 2 diabetes mellitus were distributed into three groups according to urinary albumin-to-creatinine ratio: Group A, type 2 diabetic patients with normoalbuminuria (urinary albumin-to-creatinine ratio <30 mg/g); Group B, type 2 diabetic patients with microalbuminuria (urinary albumin-to-creatinine ratio = 30–300 mg/g); Group C, type 2 diabetic patients with macroalbuminuria (urinary albumin-to-creatinine ratio ≥300 mg/g). Levels of inflammatory markers (neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio) were recorded and compared among the three groups.

Results

Significant differences were detected between the groups in terms of neutrophil-to-lymphocyte ratio (p = 0.000) and platelet-to-lymphocyte ratio (p = 0.000). Receiver operating characteristic curve analysis of inflammatory markers and microalbuminuria prediction demonstrated an area under curve (AUC) of 0.869 for neutrophil-to-lymphocyte ratio (confidence interval: 0.813–0.926, p = 0.000) and 0.739 for platelet-to-lymphocyte ratio (confidence interval: 0.662–0.815, p = 0.000).

Conclusion

Increased neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were significantly correlated with diabetic nephropathy, and high neutrophil-to-lymphocyte ratio & platelet-to-lymphocyte ratio may be served as a predictor and a prognostic risk marker of diabetic nephropathy.

Sulfonylureas in the Current Practice of Type 2 Diabetes Management: Are They All the Same? Consensus from the Gulf Cooperation Council (GCC) Countries Advisory Board on Sulfonylureas

Since their inception in the commercial market in the mid-twentieth century, sulfonylureas (SUs) have remained a therapeutic option in the management of type 2 diabetes (T2D). Despite their established glucose-lowering effects, there is no consensus among global experts and modern guidelines regarding the priority of SUs in relation to other therapeutic options, given the lack of evidence that SUs are associated with a low risk of macrovascular events and excess mortality. However, findings from recent trials and real-time observations have resolved this contentious issue somewhat, albeit to varying degrees. The present consensus discusses the role of SUs in contemporary diabetes management in the Gulf Cooperation Council (GCC) countries. Regional experts from these countries gathered virtually to formulate a consensus following presentations of topics relevant to SU therapy with an emphasis on gliclazide, including long-term efficacy, cost, end-organ benefits, and side effects, based on up-to-date evidence. The present narrative review reflects the conclusions of this assembly and provides a platform upon which future guidelines for the use of SUs in the GCC can be tailored.

Albuminuric and non-albuminuric reduced eGFR phenotypes in youth with type 1 diabetes: Factors associated with cardiometabolic risk

BACKGROUND AND AIM

Albuminuria and reduced eGFR are hallmarks of Diabetic Kidney Disease in adults. Our aim was to analyze factors associated with albuminuric and non-albuminuric mildly reduced eGFR phenotypes in youths with type 1 diabetes.

METHODS AND RESULTS

This multicenter cross-sectional study included 1549 youths (age 5-17 years) with type 1 diabetes enrolled at 14 Italian Pediatric Diabetes Centers. Albuminuria, creatinine, glycosylated hemoglobin (HbA1c), lipids, blood pressure (BP), neutrophils (N) and lymphocytes (L) count were analyzed. Uric acid (UA) was available in 848 individuals. Estimated GFR (eGFR) was calculated using bedside Schwartz's equation. The sample was divided in three phenotypes: 1) normoalbuminuria and eGFR ≥90 mL/min/1.73 m² (reference category, n = 1204), 2) albuminuric and normal GFR phenotype (n = 106), 3) non-albuminuric mildly reduced GFR (MRGFR) phenotype (eGFR 60-89 mL/min/1.73 m², n = 239). Albuminuric and non-albuminuric reduced eGFR phenotypes were significantly associated with autoimmune thyroiditis (P =0.028 and P=0.044, respectively). Albuminuric phenotype showed high risk of high HbA1c (P=0.029), high BP (P < 0.001), and low HDL-C (P =0.045) vs reference category. Non-albuminuric MRGFR phenotype showed high risk of high BP (P < 0.0001), low HDL-C (P =0.042), high Triglycerides/HDL-C ratio (P =0.019), and high UA (P < 0.0001) vs reference category.

CONCLUSION

Non albuminuric MRGFR phenotype is more prevalent than albuminuric phenotype and shows a worst cardiometabolic risk (CMR) profile). Both phenotypes are associated with autoimmune thyroiditis. Our data suggest to evaluate both albuminuria and eGFR earlier in type 1 diabetes to timely identify young people with altered CMR profile.

Protein glycation - biomarkers of metabolic dysfunction and early-stage decline in health in the era of precision medicine

Protein glycation provides a biomarker in widespread clinical use, glycated hemoglobin HbA1c (A1C). It is a biomarker for diagnosis of diabetes and prediabetes and of medium-term glycemic control in patients with established diabetes. A1C is an early-stage glycation adduct of hemoglobin with glucose; a fructosamine derivative. Glucose is an amino group-directed glycating agent, modifying N-terminal and lysine sidechain amino groups. A similar fructosamine derivative of serum albumin, glycated albumin (GA), finds use as a biomarker of glycemic control, particularly where there is interference in use of A1C. Later stage adducts, advanced glycation endproducts (AGEs), are formed by the degradation of fructosamines and by the reaction of reactive dicarbonyl metabolites, such as methylglyoxal. Dicarbonyls are arginine-directed glycating agents forming mainly hydroimidazolone AGEs. Glucosepane and pentosidine, an intense fluorophore, are AGE covalent crosslinks. Cellular proteolysis of glycated proteins forms glycated amino acids, which are released into plasma and excreted in urine. Development of diagnostic algorithms by artificial intelligence machine learning is enhancing the applications of glycation biomarkers. Investigational glycation biomarkers are in development for: (i) healthy aging; (ii) risk prediction of vascular complications of diabetes; (iii) diagnosis of autism; and (iv) diagnosis and classification of early-stage arthritis. Protein glycation biomarkers are influenced by heritability, aging, decline in metabolic, vascular, renal and skeletal health, and other factors. They are applicable to populations of differing ethnicities, bridging the gap between genotype and phenotype. They are thereby likely to find continued and expanding clinical use, including in the current era of developing precision medicine, reporting on multiple pathogenic processes and supporting a precision medicine approach.

Association Between Serum Irisin and Diabetic Nephropathy in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis

Irisin, an emerging adipokine, has been involved in the pathogenesis of type 2 diabetes mellitus (T2DM). However, previous studies evaluating the association between irisin and diabetic nephropathy (DN) showed inconsistent results. We performed a meta-analysis to evaluate the above association. Matched case-control studies evaluating the difference of serum irisin between T2DM patients with and without DN were identified via systematic search of PubMed, Embase, Cochranes' Library, China National Knowledge Infrastructure, and WanFang databases from inception to December 5, 2020. A random-effects model or a fixed-effects model was used to pool the results according to the heterogeneity. Overall, thirteen matched case-control studies including 1735 T2DM patients were included. Results of meta-analysis showed that compared to T2DM patients with normoalbuminuria, those with microalbuminuria [10 studies, standard mean difference (SMD): 1.12, 95% confidence interval (CI): 0.48-1.77, p<0.001; I²=94%] and macroalbuminuria (10 studies, SMD: 1.86, 95% CI: 0.93-2.79, p<0.001; I²=97%) had significantly lower serum irisin. Besides, the serum level of irisin was significantly lower in T2DM patients with macroalbuminuria than those with microalbuminuria (10 studies, SMD: 0.91, 95% CI: 0.44-1.38, p<0.001; I²=90%). In addition, patients with estimated glomerular infiltration rate (eGFR)<60 ml/min 1.73 m² had lower serum irisin compared to those with eGFR≥60 ml/min 1.73 m² (4 studies, SMD: 0.89, 95% CI: 0.32-1.46, p=0.002; I²=91%). In conclusion, serum irisin may be associated with albuminuria and reduced eGFR in T2DM patients.

Hundert Jahre – Insulin bleibt aktuell und notwendig

In der Behandlung des Typ-1-Diabetes ist die Therapie mit Insulin auch 100 Jahre nach seiner Entdeckung weiterhin eine lebensnotwendige Therapie. Der pharmakologische Fortschritt hat die Behandlung erheblich erleichtert und nähert sich der physiologischen Insulin-Sekretion zunehmend an. In der Behandlung des Typ-2-Diabetes hingegen ist die Insulin-Therapie bei den meisten Patienten zunächst nicht notwendig. Lebensstil-Interventionen und moderne Nicht-Insulin Antidiabetika können häufig zu einer lang andauernden Kontrolle der Erkrankung führen. Die Heterogenität des Typ-2-Diabetes führt jedoch dazu, dass einige Patienten früh von einer Insulin-Therapie profitieren. Auch beim Typ-2-Diabetes können moderne Insulin Präparate die Insulin-Behandlung deutlich erleichtern, auch in Kombination mit anderen Antidiabetika. Einleitung und Begleitung einer Insulin-Therapie gehören somit weiterhin zu den Kernaufgaben der Diabetologie.

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.

Distinct eGFR trajectories are associated with risk of myocardial infarction in people with diabetes or prediabetes

BACKGROUND

The relationship between estimated glomerular filtration rate (eGFR) trajectories and myocardial infarction (MI) has so far been unclear in people with diabetes or prediabetes. We aimed to identify common eGFR trajectories in people with diabetes or prediabetes and to examine their association with MI risk.

METHODS

The data of this analysis were derived from the Kailuan study, which was a prospective community-based cohort study. The eGFR trajectories of 24 723 participants from the year 2006 to 2012 were generated by latent mixture modeling. Cox proportional hazards models were used to calculate hazard ratios (HR) and their 95% CI for the subsequent risk of MI of different eGFR trajectories.

RESULTS

We identified five distinct eGFR trajectories during 2006 to 2012 and named them according to their eGFR range and pattern over time: low-stable (9.4%), moderate-stable (31.4%), moderate-increasing (29.5%), high-decreasing (13.9%), and high-stable (15.8%). During a mean follow-up of 4.61 years, there were a total of 235 incident MI. Although the high-decreasing group had similar eGFR levels to the moderate-stable group during the last exposure period, the risk was much higher (adjusted HR, 3.57; 95% CI, 1.63-7.85 vs adjusted HR, 2.88; 95% CI, 1.36-6.08). Notably, the moderate-increasing group had reached the normal range, but still had a significantly increased risk (adjusted HR, 2.63; 95% CI, 1.24-5.55).

CONCLUSIONS

eGFR trajectories were associated with MI risk in people with diabetes or prediabetes. These observations suggest that long-term trajectories of eGFR may be important for risk prediction of MI and should be highlighted in primary prevention.

The Role of Diffusion-Weighted MRI and Apparent Diffusion Coefficient in Assessment of Diabetic Kidney Disease: Preliminary Experience Study

Background

Diabetic kidney disease is the most common cause of ESRD. There is poor correlation between the degree of renal fibrosis and current screening markers. A noninvasive imaging technique is needed to assess the degree of structural changes in the kidney. The aim of this study was to assess the role of apparent diffusion coefficient (ADC) in the diagnosis of diabetic kidney disease. Forty adult diabetic patients with chronic kidney disease as well as 20 age- and sex-matched adult healthy controls were recruited from Nephrology Department of our University Hospital. All patients underwent renal MR-DWI and ADC mapping on a 1.5-T scanner (Philips Achieva) using phased array body coil.

Results

Among the studied 40 diabetic patients, five groups of patients were resulted 8 patients for each and the ADC values were inversely correlated with advancement in renal parenchymal affection, ie, in late stages of the disease the ADC values were lower than in early stages. The mean ADC values of renal parenchyma in patients with diabetic kidney disease were considerably lower than that of healthy controls with normal renal function (2.1±0.3x10^-3 mm²/s vs 2.4±0.1x10^-3 mm²/s with p<0.001).

Conclusion

ADC value is a possible noninvasive technique in evaluating the stage of renal dysfunction with assessment of disease progression.

Bu-Shen-Huo-Xue Decoction Ameliorates Diabetic Nephropathy by Inhibiting Rac1/PAK1/p38MAPK Signaling Pathway in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

Diabetic nephropathy (DN), a leading cause of end-stage renal disease, is associated with high morbidity and mortality rates worldwide and the development of new drugs to treat DN is urgently required. Bu-Shen-Huo-Xue (BSHX) decoction is a traditional Chinese herbal formula, made according to traditional Chinese medicine (TCM) theory, and has been used clinically to treat DN. In the present study, we established a high-fat diet/streptozotocin-induced diabetic mouse model and treated the mice with BSHX decoction to verify its therapeutic effects in vivo. Ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was applied to analyze the chemical composition and active compounds of BSHX decoction. Markers of podocyte epithelial-mesenchymal transition and the Rac1/PAK1/p38MAPK signaling pathway were evaluated to investigate the mechanism underlying function of BSHX decoction. BSHX decoction effectively alleviated diabetic symptoms, according to analysis of the renal function indicators, serum creatinine, blood urea nitrogen, serum uric acid, and urinary albumin excretion rate, as well as renal histopathology and ultrastructural pathology of DN mice. We identified 67 compounds, including 20 likely active compounds, in BSHX decoction. The podocyte markers, nephrin and podocin, were down-regulated, while the mesenchymal markers, α-SMA and FSP-1, were up-regulated in DN mouse kidney; however, the changes in these markers were reversed on treatment with BSHX decoction. GTP-Rac1 was markedly overexpressed in DN mice and its levels were significantly decreased in response to BSHX decoction. Similarly, levels of p-PAK1 and p-p38MAPK which indicate Rac1 activation, were reduced on treatment with BSHX decoction. Together, our data demonstrated that BSHX decoction ameliorated renal function and podocyte epithelial-mesenchymal transition via inhibiting Rac1/PAK1/p38MAPK signaling pathway in high-fat diet/streptozotocin-induced diabetic mice. Further, we generated a quality control standard and numerous potential active compounds from BSHX decoction for DN.

Indications for renal biopsy in patients with diabetes. Joint position statement of the Italian Society of Nephrology and the Italian Diabetes Society

AIMS

This joint document of the Italian Society of Nephrology and the Italian Diabetes Society reviews the main indications to perform a renal biopsy in diabetic patients, according to the recommendations of a panel of experts based on all available scientific evidence.

DATA SYNTHESIS

Renal biopsy has a pivotal role in assessing the nature and severity of renal injury in patients with diabetic kidney disease (DKD). The procedure is mandatory in the presence of one of more of the following features: rapid onset or progression of albuminuria or sudden onset of nephrotic syndrome, rapid GFR decline with or without albuminuria, hematuria, active urine sediment, clinical and/or laboratory suspicion of other systemic diseases, and, in patients with type 1 diabetes, short diabetes duration and absence of retinopathy. Indeed, ~40% of diabetic individuals with kidney injury undergoing renal biopsy are affected by a non-diabetic renal disease (NDRD). Furthermore, the histological evaluation of patients with suspected classical diabetic nephropathy allows to define the extent of glomerular, tubulo-interstitial and vascular lesions, thus providing important prognostic (and potentially therapeutic) data. In the future, the indications for renal biopsy might be extended to the definition of the histological lesions underlying the "nonalbuminuric" DKD phenotypes, as well as to the evaluation of the response to treatment with the new anti-hyperglycemic drugs that provide cardiorenal protection.

CONCLUSIONS

In view of the heterogeneous clinical presentation and course of DKD and of the related heterogeneous histopathological patterns, a more extensive use of renal biopsy may be crucial to provide valuable information with important pathogenic, diagnostic, prognostic, and therapeutic implications.

Development of glomerular hyperfiltration, a multiphasic phenomenon

The trajectory of glomerular filtration rate (GFR) in relation to glomerular hyperfiltration (GHF) has been unknown. It was evaluated retrospectively in 23,982 GHF-free health examinees who were followed for 2-10 yr (mean: 5.1 yr). GFR was estimated by the serum creatinine concentration, and GHF was defined as age- and sex-specific estimated GFR (eGFR) ≥ 95% of the Japanese general population. The temporal profile of eGFR was plotted in a GHF-centered way, which was fitted to a random coefficient linear mixed model. Of the 23,982 subjects, 797 and 23,185 subjects developed or did not develop GHF, respectively, so that they were termed as the GHF₍₊₎ and GHF_(-) groups. At baseline, median eGFR was significantly elevated in the GHF₍₊₎ group compared with in the GHF_(-) group: 94.1 versus 77.3 mL/min/1.73 m² (P < 0.001). Elevation of basal eGFR lasted for a mean (SD) of 3.3 (1.9) yr in the GHF₍₊₎ group; mean eGFR then rose to the GHF range, which was 108.5 mL/min/1.73 m². The eGFR decline after the peak was steeper in the GHF₍₊₎ group than in the GHF_(-) group: -0.984 versus -0.497 mL/min/1.73 m²/yr (P < 0.001). Baseline eGFR, but no other variable, well predicted incident GHF, with an area under the receiver operating characteristic curve of 0.87 (95% confidence interval: 0.86-0.88). In conclusion, GHF occurs as a chronic, multiphasic phenomenon: initially with a sustained GFR elevation for years, followed by a GFR surge to the GHF range, which was accompanied by accelerated GFR declining.

Renal protection with glucagon-like peptide-1 receptor agonists

There is an unmet need for renoprotective drugs for more pronounced reduction of albuminuria beyond that provided by renin-angiotensin system (RAS) blockers and for effective slowdown of eGFR decline independent of albuminuria. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have proven effective in reducing prespecified secondary composite kidney outcomes in cardiovascular outcome trials. However, GLP-1 RAs showed a prevailing anti-albuminuric effect, additional to that of RAS blockers, and a non-significant risk reduction in worsening of kidney function, at variance with sodium-glucose cotransporter 2 inhibitors. Mechanisms underlying renal protection with GLP-1 RAs are porly understood. Though treatment with GLP-1 RAs resulted in better glycaemic, blood pressure and body weight control versus placebo, correction for on-trial changes in these parameters did not significantly affect results. Anti-inflammatory/anti-oxidant effects via intracellular signalling through protein kinase A, natriuretic effect via inhibition of sodium-hydrogen exchanger 3 and reduction of hyperfiltration have been proposed as direct renoprotective effects.