Development and progression of renal insufficiency with and without albuminuria in adults with type 1 diabetes in the diabetes control and complications trial and the epidemiology of diabetes interventions and complications study

Association of thyroid autoantibodies and diabetic kidney disease in hospitalised patients with type 2 diabetes mellitus: a cross-sectional study from a Chinese university hospital

OBJECTIVES

To analyse and explore the association between thyroid autoantibodies and diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM).

DESIGN

A cross-sectional study.

SETTING

Patients were from the inpatient unit at The Second Endocrinology Department of Shengjing Hospital Affiliated to China Medical University (Shenyang, China) between January 2015 and September 2019.

PARTICIPANTS

A total of 150 Chinese adults with T2DM were included in the study, including 83 men and 67 women. Their age ranged between 25 and 92 years.

METHODOLOGY

They grouped by the presence of DKD, urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate, and levels of thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb). Data on the patients' general characteristics and laboratory measurements (levels of fasting plasma glucose, glycated haemoglobin, and albumin; renal function; and thyroid function) were collected. Binary logistic regression was performed to identify risk factors for DKD.

RESULTS

The level of TPOAb, the positivity rates of TPOAb (p<0.01) and TgAb (p<0.05) were higher in patients with DKD than in those without DKD. The TPOAb level in patients with a UACR<30 mg/g creatinine was lower than that in patients with a UACR between 30 and 300 mg/g creatinine (p<0.05). The prevalence of DKD was higher in patients with a TPOAb-positive or TgAb-positive status. The result of binary logistic regression analysis showed that a TPOAb-positive status was significantly associated with DKD in patients with T2DM (OR=7.683, 95% CI 1.583 to 37.286, p<0.05).

CONCLUSIONS

TPOAb-positive status is in association with DKD in patients with T2DM. Large scale, prospective cohort studies are warranted to confirm our findings.

11. Chronic Kidney Disease and Risk Management: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Progression and regression of kidney disease in type 1 diabetes

Diabetic kidney disease is distinguished by the presence of albuminuria, hypertension, declining kidney function, and a markedly elevated cardiovascular disease risk. This constellation of clinical features drives the premature mortality associated with type 1 diabetes. The first epidemiological investigations concerning type 1 diabetes-related albuminuria date back to the 1980s. The early studies found that proteinuria - largely equivalent to severe albuminuria - developed in 35 to 45% of individuals with type 1 diabetes, with the diabetes duration-specific incidence rate pattern portraying one or two peaks. Furthermore, moderate albuminuria, the first detectable sign of diabetic kidney disease, was found to nearly inexorably progress to overt kidney disease within a short span of time. Since the early reports, studies presenting more updated incidence rates have appeared, although significant limitations such as study populations that lack broad generalizability, study designs vulnerable to substantive selection bias, and constrained follow-up times have been encountered by many. Nevertheless, the most recent reports estimate that in modern times, moderate - instead of severe - albuminuria develops in one-third of individuals with type 1 diabetes; yet, a considerable part (up to 40% during the first ten years after the initial albuminuria diagnosis) progresses to more advanced stages of the disease over time. An alternative pathway to albuminuria progression is its regression, which affects up to 60% of the individuals, but notably, the relapse rate to a more advanced disease stage is high. Whether albuminuria regression translates into a decline in cardiovascular disease and premature mortality risk is an area of debate, warranting more detailed research in the future. Another unclear but alarming feature is that although the incidence of severe albuminuria has fallen since the 1930s, the decline seems to have reached a plateau after the 1980s. This stagnation may be due to the lack of kidney-protective medicines since the early 1980s, as the recent breakthroughs in type 2 diabetes have not been applicable to type 1 diabetes. Therefore, novel treatment strategies are at high priority within this patient population.

Plasma leucine-rich α-2-glycoprotein 1 - a novel marker of diabetic kidney disease in children and adolescents with type 1 diabetes mellitus?

BACKGROUND

Glomerular endothelial dysfunction and neoangiogenesis play a significant role in the pathogenesis of diabetic kidney disease (DKD). Leucine-rich α-2 glycoprotein 1 (LRG1) is a recently discovered protein that participates in the molecular pathway of inflammation and angiogenesis. We aimed to investigate efficacy of LRG1 to predict estimated glomerular filtration rate (eGFR) decrease in children and adolescents with type 1 diabetes mellitus (T1DM).

METHODS

The study comprised 72 participants with diabetes duration for ≥ 2 years. At study initiation, LRG1, urine albumin, eGFR (cystatin C-based, and Schwartz), HbA1c, and lipid values were evaluated and diabetes-related clinical features and anthropometric measurements were collected. These results were compared with final control values after ≥ 1 year. Patients were divided into subgroups according to presence of albuminuria progression, eGFR decrease, and metabolic control parameters.

RESULTS

There was positive correlation between LRG1 level and Schwartz and cystatin C-based eGFR decline (r = 0.360, p = 0.003; r = 0.447, p = 0.001, respectively), and negative correlation between final cystatin C-based eGFR and LRG1 (p = 0.01, r = -0.345). Patients with cystatin C-based eGFR decrease > 10% had significantly higher LRG1 levels (p = 0.03), however, LRG1 was not different between albuminuria progression subgroups. A 0.282 μg/ml increase in LRG1 correlated with a 1% decrease in eGFR in simple linear regression analysis (β = 0.282, %CI 0.11-0.45, p = 0.001) and LRG1 was an independent predictor of GFR decline even in the presence of covariates.

CONCLUSIONS

Our study supports the relationship between plasma LRG1 and eGFR decline and suggests LRG1 may be an early marker of DKD progression in children with T1DM. A higher resolution version of the Graphical abstract is available as Supplementary information.

[Non-Classical Clinical Types and Pathological Changes of Diabetic Kidney Disease: A Review]

Diabetic kidney disease (DKD) is a common complication of diabetes mellitus and approximately 1/3 of diabetic patients may progress to DKD. A typical early clinical manifestation of DKD is microalbuminuria and patients may present with macroproteinuria accompanied by a decrease in renal function condition as the disease progresses. It is generally believed that the likelihood of a reversal of the disease is reduced after the development of macroproteinuria in patients with DKD, and that eventually some patients' condition may develop into end-stage renal disease (ESRD). Moreover, the thickening of the glomerular basement membrane, mesangial matrix expansion, Kimmelstiel-Wilson (K-W) nodules, and glomerulosclerosis in end-stage diabetes mellitus are typical pathologic changes of DKD. However, some DKD patients, especially those with type 2 diabetes mellitus (T2DM) combined with DKD, may have diverse clinical manifestations, showing variations in disease progression and regression, and manifesting as non-classical types of DKD, such as normoalbuminuric DKD, proteinuria-reduced DKD, and DKD with rapid decline in renal function. In addition, the formation of crescents, a special pathological change, is observed in renal biopsy. However, this issue is currently under-recognized by clinicians and therefore deserves more attention. In order to improve clinicians' understanding of the presentations and pathological changes of non-classical DKD and the level of DKD prevention and treatment in China, we present a preliminary introduction to the clinical phenotypes and pathological changes of non-classical types of DKD in this paper by summarizing the findings of our prior studies as well as domestic and international literature.

Multifaceted relationship between diabetes and kidney diseases: Beyond diabetes

Diabetes mellitus is one of the most common causes of chronic kidney disease. Kidney involvement in patients with diabetes has a wide spectrum of clinical presentations ranging from asymptomatic to overt proteinuria and kidney failure. The development of kidney disease in diabetes is associated with structural changes in multiple kidney compartments, such as the vascular system and glomeruli. Glomerular alterations include thickening of the glomerular basement membrane, loss of podocytes, and segmental mesangiolysis, which may lead to microaneurysms and the development of pathognomonic Kimmelstiel-Wilson nodules. Beyond lesions directly related to diabetes, awareness of the possible coexistence of nondiabetic kidney disease in patients with diabetes is increasing. These nondiabetic lesions include focal segmental glomerulosclerosis, IgA nephropathy, and other primary or secondary renal disorders. Differential diagnosis of these conditions is crucial in guiding clinical management and therapeutic approaches. However, the relationship between diabetes and the kidney is bidirectional; thus, new-onset diabetes may also occur as a complication of the treatment in patients with renal diseases. Here, we review the complex and multifaceted correlation between diabetes and kidney diseases and discuss clinical presentation and course, differential diagnosis, and therapeutic oppor-tunities offered by novel drugs.

Clinical Profile of Nonproteinuric Kidney Disease in Type 2 Diabetic Patients in India

Background

Diabetic kidney disease (DKD) is the commonest cause of end-stage renal disease (ESRD) across the world. Development of microalbuminuria is the earliest marker of DKD and predicts progressive decline in estimated glomerular filtration rate (eGFR). However, recent evidence has suggested that a significant proportion of type 2 diabetic patients have chronic kidney disease (CKD) without proteinuria.

Methods

In this single-center, prospective observational study, 400 consecutive type 2 diabetic patients with either overt proteinuria (>500 mg/day) and/or renal dysfunction eGFR <60 ml/min/1.73 m2) were recruited. Baseline demographic and clinical data were recorded. eGFR and proteinuria were recorded at 6 months and 1 year. Patients with proteinuric (proteinuria >0.5 g/day) and nonproteinuric phenotypes were compared for progression of renal dysfunction in terms of doubling of serum creatinine and need for dialysis.

Results

In our study cohort, 106 (26.5%) were nonproteinuric. Both the groups were similar in terms of gender, duration of diabetes, comorbidities, body mass index (BMI), blood pressure control, and glycemic control. The nonproteinuric group was older (56.5 ± 2.1 vs. 54.7 ± 11.6 years, P = 0.012), had lesser prevalence of diabetic retinopathy (49 [46.2%] vs. 218 [74.1%], P < 0.001), higher hemoglobin levels (11.3 ± 1.7 vs. 10.5 ± 2.0 g/dl, P < 0.001), and higher cholesterol levels (169.3 ± 43.3 vs 157.1 ± 58.1 mg/dl, P = 0.025). The nonproteinuric phenotype had higher eGFR at baseline, 6 months, and 1 year. However, doubling of serum creatinine (10 [9.4%] vs. 48 [16.3%]) and progression to ESRD (5 [4.7%] vs. 19 [6.5%], P = 0.159) were not different between the two phenotypes.

Conclusion

Nonproteinuric DKD is common. Patients with nonproteinuric DKD tend to be older with a slower decline in eGFR.

Novel biomarkers for prognosticating diabetic kidney disease progression

The global burden of diabetic kidney disease (DKD) is escalating, and it remains as a predominant cause of the end-stage renal disease (ESRD). DKD is associated with increased cardiovascular disease and morbidity in all types of diabetes. Prediction of progression with albuminuria and eGFR is challenging in DKD, especially in non-proteinuric DKD patients. The pathogenesis of DKD is multifactorial characterized by injury to all components of the nephron, whereas albuminuria is an indicator of only glomerular injury. The limits in the diagnostic and prognostic value of urine albumin demonstrate the need for alternative and clinically significant early biomarkers, allowing more targeted and effective diabetic treatment, to reduce the burden of DKD and ESRD. Identification of biomarkers, based on multifactorial pathogenesis of DKD can be the crucial paradigm in the treatment algorithm of DKD patients. This review focuses on the potential biomarkers linked to DKD pathogenesis, particularly with the hope of broadening the diagnostic window to identify patients with different stages of DKD progression.

Heterogeneity in Kidney Histology and Its Clinical Indicators in Type 2 Diabetes Mellitus: A Retrospective Study

The heterogeneous spectrum of kidney disease in diabetes ranges from albuminuric or non-albuminuric diabetic kidney disease to non-diabetic kidney diseases. Presumptive clinical diagnosis of diabetic kidney disease may lead to an erroneous diagnosis.

MATERIAL AND METHOD

We analyzed the clinical profile and kidney biopsy of a total of 66 type 2 diabetes patients. Based on kidney histology, they were divided into-Class I (Diabetic Nephropathy), Class II (Non-diabetic kidney disease), and Class III (Mixed lesion). Demographic data, clinical presentation, and laboratory values were collected and analyzed. This study tried to examine the heterogeneity in kidney disease, its clinical indicator, and the role of kidney biopsy in the diagnosis of kidney disease in diabetes.

RESULTS

Class I consisted of 36(54.5%), class II 17(25.8%), and class III 13(19.7%) patients. The commonest clinical presentation was nephrotic syndrome 33(50%) followed by chronic kidney disease 16(24.4%) and asymptomatic urinary abnormality 8(12.1%). Diabetic retinopathy (DR) was present in 27(41%) cases. DR was significantly higher in the class I patients (p < 0.05). Specificity and positive predictive values of DR for DN were 0.83 and 0.81, respectively (sensitivity 0.61; negative predictive values 0.64). The Association of the duration of diabetes and the level of proteinuria with DN was statistically not significant (p > 0.05). Idiopathic MN (6) and Amyloidosis (2) were the most common isolated NDKD; whereas diffuse proliferative glomerulonephritis (DPGN) (7) was the commonest NDKD in mixed disease. Another common form of NDKD in mixed disease was Thrombotic Microangiopathy (2) and IgA nephropathy (2). NDKD was observed in 5(18.5%) cases in presence of DR. We noted biopsy-proven DN even in 14(35.9%) cases without DR, in 4(50%) cases with microalbuminuria and 14(38.9%) cases with a short duration of diabetes.

CONCLUSION

Almost half (45%) of cases with atypical presentation have non-diabetic kidney disease (NDKD), though even among these cases with atypical presentation diabetic nephropathy (either alone or in mixed form) is commonly seen in 74.2% of cases. DN has been seen in a subset of cases without DR, with microalbuminuria, and with a short duration of diabetes. Clinical indicators were insensitive in distinguishing DN Vs NDKD. Hence, a kidney biopsy may be a potential tool for the accurate diagnosis of kidney disease.

11. Chronic Kidney Disease and Risk Management: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Novel biomarkers for diabetic kidney disease

Although diabetic kidney disease (DKD) remains one of the leading causes of reduced lifespan in patients with diabetes mellitus; its prevalence has failed to decline over the past 30 years. To identify those at high risk of developing DKD and disease progression at an early stage, extensive research has been ongoing in the search for prognostic and surrogate endpoint biomarkers for DKD. Although biomarkers are not used routinely in clinical practice or prospective clinical trials, many biomarkers have been developed to improve the early identification and prognostication of patients with DKD. Novel biomarkers that capture one specific mechanism of the DKD disease process have been developed, and studies have evaluated the prognostic value of assay-based biomarkers either in small sets or in combinations involving multiple biomarkers. More recently, several studies have assessed the prognostic value of omics- based biomarkers that include proteomics, metabolomics, and transcriptomics. This review will first describe the biomarkers used in current practice and their limitations, and then summarize the current status of novel biomarkers for DKD with respect to assay- based protein biomarkers, proteomics, metabolomics, and transcriptomics.

Nomogram-Based Chronic Kidney Disease Prediction Model for Type 1 Diabetes Mellitus Patients Using Routine Pathological Data

Type 1 diabetes mellitus (T1DM) patients are a significant threat to chronic kidney disease (CKD) development during their life. However, there is always a high chance of delay in CKD detection because CKD can be asymptomatic, and T1DM patients bypass traditional CKD tests during their routine checkups. This study aims to develop and validate a prediction model and nomogram of CKD in T1DM patients using readily available routine checkup data for early CKD detection. This research utilized 1375 T1DM patients’ sixteen years of longitudinal data from multi-center Epidemiology of Diabetes Interventions and Complications (EDIC) clinical trials conducted at 28 sites in the USA and Canada and considered 17 routinely available features. Three feature ranking algorithms, extreme gradient boosting (XGB), random forest (RF), and extremely randomized trees classifier (ERT), were applied to create three feature ranking lists, and logistic regression analyses were performed to develop CKD prediction models using these ranked feature lists to identify the best performing top-ranked features combination. Finally, the most significant features were selected to develop a multivariate logistic regression-based CKD prediction model for T1DM patients. This model was evaluated using sensitivity, specificity, accuracy, precision, and F1 score on train and test data. A nomogram of the final model was further generated for easy application in clinical practices. Hypertension, duration of diabetes, drinking habit, triglycerides, ACE inhibitors, low-density lipoprotein (LDL) cholesterol, age, and smoking habit were the top-8 features ranked by the XGB model and identified as the most important features for predicting CKD in T1DM patients. These eight features were selected to develop the final prediction model using multivariate logistic regression, which showed 90.04% and 88.59% accuracy in internal and test data validation. The proposed model showed excellent performance and can be used for CKD identification in T1DM patients during routine checkups.

Randomized, double-blind, placebo-controlled phase 3 study of bardoxolone methyl in patients with diabetic kidney disease: Design and baseline characteristics of AYAME study

BACKGROUND

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD), but currently available treatments do not improve kidney function or prevent the initiation of dialysis/kidney replacement therapy. A previous study demonstrated that bardoxolone methyl improves the estimated glomerular filtration rate (eGFR), but the study was prematurely terminated because of an imbalance in heart failure between treatment groups. The subsequent phase 2 TSUBAKI study demonstrated no incidence of heart failure and an improved eGFR and GFR as determined by inulin clearance in DKD patients.

METHODS

This randomized, double-blind, placebo-controlled multicenter phase 3 study was designed to assess the efficacy and safety of bardoxolone methyl in DKD patients with an eGFR of ≥ 15.0 to < 60.0 mL/min/1.73 m2 and urinary albumin/creatinine ratio of ≤3500 mg/g but without risk factors for heart failure. The primary endpoint is the time to onset of a ≥ 30% decrease in the eGFR or ESKD. Randomized patients (1:1) have been under treatment with once-daily oral bardoxolone methyl (5, 10, or 15 mg by intra-patient dose adjustment) or placebo for at least 3 years. Results The 1013 patients' mean age is 65.9 years, 21.5% are female, the mean eGFR is 37.84 mL/min/1.73 m2, and the median urinary albumin/creatinine ratio is 351.80 mg/g.

CONCLUSIONS

Appropriate patients are enrolled in this study. This study will investigate the long-term efficacy and safety of bardoxolone methyl in DKD patients covering a wider range of the eGFR (≥15.0 to < 60.0 mL/min/1.73 m2) and albuminuria (≤3500 mg/g) compared with previous studies.

Serum Cystatin C Trajectory Is a Marker Associated With Diabetic Kidney Disease

Objective

To explore the association of the trajectory of serum Cystatin C (Cysc) with diabetic kidney disease (DKD), a retrospective cohort study of Chinese subjects was carried out.

Method

A review of 2,928 diabetes mellitus (DM) patients admitted to the clinic and ward of the Endocrinology Department, Shengjing Hospital of China Medical University from January 1, 2014 to December 31, 2014 was performed. Subsequent visits to the hospital were followed until December 31, 2020. The primary endpoint was the incidence of DKD as diagnosed by urinary albumin/creatinine ratio ≥30 mg/g and/or estimated glomerular filtration rate <60 ml/min per 1.73 m2. Healthy control subjects were identified from a health checkup database in Shengjing Hospital from 2016 to 2019. The latent class growth mixed modeling (LCGMM) method was used to analyze latent classes of serum Cysc in healthy and DM subjects. Finally, the hazard ratios (HRs) of latent classes of Cysc in DM subjects were analyzed by Cox regression analysis.

Results

A total of 805 type 2 diabetes mellitus (T2DM) and 349 healthy subjects were included in the trial. The HRs of quartiles of baseline Cysc in T2DM subjects were 7.15 [95% confidence interval (CI), 2.79 to 25.57], 2.30 (95% CI, 1.25 to 4.24), and 2.05 (95% CI, 1.14 to 3.70), respectively, for quartile 4 (Q4), Q3, and Q2 when compared with Q1. Through LCGMM, a 1-class linear model was selected for the Cysc latent class in healthy subjects. In contrast, a 3-class linear model was selected for that in DM subjects. The slopes of the three latent classes in T2DM subjects were larger than the slope in healthy subjects. The HRs of incident DKD were 3.43 (95% CI, 1.93 to 6.11) for the high-increasing class and 1.80 (95% CI, 1.17 to 2.77) for the middle-increasing class after adjusting for confounding variables.

Conclusions

Patients with T2DM had a higher velocity of increase in Cysc than healthy subjects. Patients with high baseline Cysc values and high latent increasing velocity of Cysc had a higher risk of developing DKD in later life. More attention should be paid to patients with these high-risk factors.

Glomerular filtration rate as a kidney outcome of diabetic kidney disease: a focus on new antidiabetic drugs

Diabetes has reached epidemic proportions, both in Korea and worldwide and is associated with an increased risk of chronic kidney disease and kidney failure (KF). The natural course of kidney function among people with diabetes (especially type 2 diabetes) may be complex in real-world situations. Strong evidence from observational data and clinical trials has demonstrated a consistent association between decreased estimated glomerular filtration rate (eGFR) and subsequent development of hard renal endpoints (such as KF or renal death). The disadvantage of hard renal endpoints is that they require a long follow-up duration. In addition, there are many patients with diabetes whose renal function declines without the appearance of albuminuria, measurement of the eGFR is emphasized. Many studies have used GFR-related parameters, such as its change, decline, or slope, as clinical endpoints for kidney disease progression. In this respect, understanding the trends in GFR changes could be crucial for developing clinical management strategies for the prevention of diabetic complications. This review focuses on the clinical implication of the eGFR-related parameters that have been used so far in diabetic kidney disease. We also discuss the use of recently developed new antidiabetic drugs for kidney protection, with a focus on the GFR as clinical endpoints.

Advancements in nanomedicines for the detection and treatment of diabetic kidney disease

In the diabetic kidneys, morbidities such as accelerated ageing, hypertension and hyperglycaemia create a pro-inflammatory microenvironment characterised by extensive fibrogenesis. Radiological techniques are not yet optimised generating inconsistent and non-reproducible data. The gold standard procedure to assess renal fibrosis is kidney biopsy, followed by histopathological assessment. However, this method is risky, invasive, subjective and examines less than 0.01% of kidney tissue resulting in diagnostic errors. As such, less than 10% of patients undergo kidney biopsy, limiting the accuracy of the current diabetic kidney disease (DKD) staging method. Standard treatments suppress the renin-angiotensin system to control hypertension and use of pharmaceuticals aimed at controlling diabetes have shown promise but can cause hypoglycaemia, diuresis and malnutrition as a result of low caloric intake. New approaches to both diagnosis and treatment are required. Nanoparticles (NPs) are an attractive candidate for managing DKD due to their ability to act as theranostic tools that can carry drugs and enhance image contrast. NP-based point-of-care systems can provide physiological information previously considered unattainable and provide control over the rate and location of drug release. Here we discuss the use of nanotechnology in renal disease, its application to both the treatment and diagnosis of DKD. Finally, we propose a new method of NP-based DKD classification that overcomes the current systems limitations.

Urinary miRNA profiles in chronic kidney injury - Benefits of extracellular vesicle enrichment and miRNAs as potential biomarkers for renal fibrosis, glomerular injury and endothelial dysfunction

Micro-RNAs (miRNAs) are regulators of gene expression and play an important role in physiological homeostasis and disease. In biofluids miRNAs can be found in protein complexes or in extracellular vesicles (EVs). Altered urinary miRNAs are reported as potential biomarkers for chronic kidney disease (CKD). In this context we compared established urinary protein biomarkers for kidney injury with urinary miRNA profiles in obese ZSF1 and hypertensive renin transgenic rats. Additionally, the benefit of urinary EV enrichment was investigated in vivo and the potential association of urinary miRNAs with renal fibrosis in vitro. Kidney damage in both rat models was confirmed by histopathology, proteinuria, and increased levels of urinary protein biomarkers. In total 290 miRNAs were elevated in obese ZSF1 rats compared to lean controls, while 38 miRNAs were altered in obese ZSF1 rats during 14 to 26 weeks of age. These 38 miRNAs correlated better with disease progression than established urinary protein biomarkers. MiRNAs increased in obese ZSF1 rats were associated with renal inflammation, fibrosis, and glomerular injury. Eight miRNAs were also changed in urinary EVs of renin transgenic rats, including one which might play a role in endothelial dysfunction. EV enrichment increased the number and detection level of several miRNAs implicated in renal fibrosis in vitro and in vivo. Our results show the benefit of EV enrichment for miRNA detection and the potential of total urine and urinary EV-associated miRNAs as biomarkers of altered kidney physiology, renal fibrosis and glomerular injury, and disease progression in hypertension and obesity induced CKD.

Early Trajectory of Estimated Glomerular Filtration Rate and Long-term Advanced Kidney and Cardiovascular Complications in Type 1 Diabetes

OBJECTIVE

Rapid loss of estimated glomerular filtration rate (eGFR) within its normal range has been proposed as a strong predictor of future kidney disease. We investigated this association of eGFR slope early in the course of type 1 diabetes with long-term incidence of kidney and cardiovascular complications.

RESEARCH DESIGN AND METHODS

The annual percentage change in eGFR (slope) was calculated during the Diabetes Control and Complications Trial (DCCT) for each of 1,441 participants over a mean of 6.5 years and dichotomized by the presence or absence of early rapid eGFR loss (slope ≤-3% per year) as the exposure of interest. Outcomes were incident reduced eGFR (eGFR <60 mL/min/1.73 m2), composite cardiovascular events, or major adverse cardiovascular events (MACE) during the subsequent 24 years post-DCCT closeout follow-up.

RESULTS

At DCCT closeout (the baseline for this analysis), diabetes duration was 12 ± 4.8 years, most participants (85.9%) had normoalbuminuria, mean eGFR was 117.0 ± 13.4 mL/min/1.73 m2, and 149 (10.4%) had experienced early rapid eGFR loss over the preceding trial phase. Over the 24-year subsequent follow-up, there were 187 reduced eGFR (6.3 per 1,000 person-years) and 113 MACE (3.6 per 1,000 person-years) events. Early rapid eGFR loss was associated with risk of reduced eGFR (hazard ratio [HR] 1.81, 95% CI 1.18-2.79, P = 0.0064), but not after adjustment for baseline eGFR level (HR 0.94, 95% CI 0.53-1.66, P = 0.84). There was no association with composite cardiovascular events or MACE.

CONCLUSIONS

In people with type 1 diabetes primarily with normal eGFR and normoalbuminuria, the preceding slope of eGFR confers no additional association with kidney or cardiovascular outcomes beyond knowledge of an individual's current level.

Low-grade proteinuria and atherosclerotic cardiovascular disease: A transition study of patients with diabetic kidney disease

Diabetic kidney disease (DKD) is heterogeneous in terms of proteinuria. Patients with DKD who present with low-grade proteinuria are more likely to have nephrosclerosis rather than traditional diabetic nephropathy. The amount of proteinuria might reflect the underlying pathology of renal failure and influence the prognosis after dialysis initiation. Clinical implications of proteinuria at the start of dialysis have not been confirmed, while greater proteinuria is associated with higher risk of cardiovascular disease (CVD) in the predialysis stages of chronic kidney disease. We performed a retrospective multicenter cohort study enrolling incident hemodialysis patients with diabetes. Patients were stratified using proteinuria quartiles. We examined the association of proteinuria quartiles with types of subsequent CVD. Among the enrolled 361 patients, the estimated mean glomerular filtration rate and proteinuria was 5.4 mL/min/1.73 m² and 6.3 g/gCr, respectively. Lower quartile of proteinuria (cut-offs: 3.0, 5.4, and 8.8 g/gCr) was significantly associated with male, older age, and history of atherosclerotic CVD including coronary artery disease, peripheral arterial disease, and cerebral infarction (P_trend<0.05). Kidney size was smaller in patients with lower levels of proteinuria. Patients with higher levels of proteinuria were more likely to have proliferative diabetic retinopathy (P_trend<0.05). Multivariate competing risk analysis revealed that the first quartile of proteinuria was associated with a greater risk of atherosclerotic CVD than the third quartile (subhazard ratio [95% confidence interval]: 2.04 [1.00–4.14]). This association was attenuated after additional adjustments for history of atherosclerotic CVD. Furthermore, patients with lower quartiles of proteinuria were more likely to die of atherosclerotic CVD than those with non-atherosclerotic CVD (P_trend = 0.01). Diabetic patients with lower proteinuria at dialysis initiation were characterized by severer macroangiopathy, as shown by a more atrophic kidney and higher prevalence of past atherosclerotic CVD. Hence, they are at a high risk of developing atherosclerotic CVD.

Re-understanding and focusing on normoalbuminuric diabetic kidney disease

Diabetes mellitus (DM) has grown up to be an important issue of global public health because of its high incidence rate. About 25% of DM patients can develop diabetic foot/ulcers (DF/DFU). Diabetic kidney disease (DKD) is the main cause of end-stage kidney disease (ESKD). DF/DFU and DKD are serious complications of DM. Therefore, early diagnosis and timely prevention and treatment of DF/DFU and DKD are essential for the progress of DM. The clinical diagnosis and staging of DKD are mostly based on the urinary albumin excretion rate (UAER) and EGFR. However, clinically, DKD patients show normoalbuminuric diabetic kidney disease (NADKD) instead of clinical proteinuria. The old NADKD concept is no longer suitable and should be updated accordingly with the redefinition of normal proteinuria by NKF/FDA. Based on the relevant guidelines of DM and CKD and combined with the current situation of clinical research, the review described NADKD from the aspects of epidemiology, pathological mechanism, clinical characteristics, biomarkers, disease diagnosis, and the relationship with DF/DFU to arouse the new understanding of NADKD in the medical profession and pay attention to it.

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.

Insulin Resistance is Associated with Clinical Manifestations of Diabetic Kidney Disease (Glomerular Hyperfiltration, Albuminuria, and Kidney Function Decline)

Clinical features of diabetic kidney disease include glomerular hyperfiltration, albuminuria, and kidney function decline towards End-Stage Kidney Disease (ESKD). There are presently neither specific markers of kidney involvement in patients with diabetes nor strong predictors of rapid progression to ESKD. Serum-creatinine-based equations used to estimate glomerular filtration rate are notoriously unreliable in patients with diabetes. Early kidney function decline, reduced glomerular filtration rate, and proteinuria contribute to identifying diabetic patients at higher risk for rapid kidney function decline. Unlike proteinuria, the elevation of urinary albumin excretion in the range of microalbuminuria is frequently transient in patients with diabetes and does not always predict progression towards ESKD. Although the rate of progression of kidney function decline is usually accelerated in the presence of proteinuria, histological lesions of diabetes and ESKD may occur with normal urinary albumin excretion. No substantial reduction in the rate of ESKD associated with diabetes has been observed during the last decades despite intensified glycemic control and reno-protective strategies, indicating that existing therapies do not target underlying pathogenic mechanisms of kidney function decline. Very long-term effects of sodium-glucose transporters- 2 inhibitors and glucagon-like peptide-1 analogs remain to be defined. In patients with diabetes, glucagon secretion is typically elevated and induces insulin resistance. Insulin resistance is consistently and strongly associated with clinical manifestations of diabetic kidney disease, suggesting that reduced insulin sensitivity participates in the pathogenesis of the disease and may represent a therapeutic objective. Amelioration of insulin sensitivity in patients with diabetes is associated with cardioprotective and kidney-protective effects.

Diabetic kidney disease in children and adolescents: an update

Diabetic kidney disease (DKD), previously encountered predominantly in adult patients, is rapidly gaining center stage as a childhood morbidity and one that pediatric nephrologists are likely to encounter with increasing frequency. This is in large part due to the obesity epidemic and the consequent rise in type 2 diabetes in children and adolescents, as well as the more aggressive diabetes phenotype in today's youth with more rapid β-cell decline and faster development and progression of diabetes-related complications along with lower responsiveness to the treatments used in adults. DKD, an end-organ complication of diabetes, is at the very least a marker of, and more likely a predisposing factor for, the development of adverse cardiovascular outcomes and premature mortality in children with diabetes. On an optimistic note, several new therapeutic approaches are now available for the management of diabetes in adults, such as GLP1 receptor agonists, SGLT2 inhibitors, and DPP4 inhibitors, that have also been shown to have a favorable impact on cardiorenal outcomes. Also promising is the success of very low-energy diets in inducing remission of diabetes in adults. However, the addition of these pharmacological and dietary approaches to the management toolbox of diabetes and DKD in children and adolescents awaits thorough assessment of their safety and efficacy in this population. This review outlines the scope of diabetes and DKD, and new developments that may favorably impact the management of children and young adults with diabetes and DKD.

11. Chronic Kidney Disease and Risk Management: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

FcER1: A Novel Molecule Implicated in the Progression of Human Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a key microvascular complication of diabetes, with few therapies for targeting renal disease pathogenesis and progression. We performed transcriptional and protein studies on 103 unique blood and kidney tissue samples from patients with and without diabetes to understand the pathophysiology of DKD injury and its progression. The study was based on the use of 3 unique patient cohorts: peripheral blood mononuclear cell (PBMC) transcriptional studies were conducted on 30 patients with DKD with advancing kidney injury; Gene Expression Omnibus (GEO) data was downloaded, containing transcriptional measures from 51 microdissected glomerulous from patients with DKD. Additionally, 12 independent kidney tissue sections from patients with or without DKD were used for validation of target genes in diabetic kidney injury by kidney tissue immunohistochemistry and immunofluorescence. PBMC DKD transcriptional analysis, identified 853 genes (p < 0.05) with increasing expression with progression of albuminuria and kidney injury in patients with diabetes. GEO data was downloaded, normalized, and analyzed for significantly changed genes. Of the 325 significantly up regulated genes in DKD glomerulous (p < 0.05), 28 overlapped in PBMC and diabetic kidney, with perturbed FcER1 signaling as a significantly enriched canonical pathway. FcER1 was validated to be significantly increased in advanced DKD, where it was also seen to be specifically co-expressed in the kidney biopsy with tissue mast cells. In conclusion, we demonstrate how leveraging public and private human transcriptional datasets can discover and validate innate immunity and inflammation as key mechanistic pathways in DKD progression, and uncover FcER1 as a putative new DKD target for rational drug design.

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.

Performance Analysis of Conventional Machine Learning Algorithms for Identification of Chronic Kidney Disease in Type 1 Diabetes Mellitus Patients

Chronic kidney disease (CKD) is one of the severe side effects of type 1 diabetes mellitus (T1DM). However, the detection and diagnosis of CKD are often delayed because of its asymptomatic nature. In addition, patients often tend to bypass the traditional urine protein (urinary albumin)-based CKD detection test. Even though disease detection using machine learning (ML) is a well-established field of study, it is rarely used to diagnose CKD in T1DM patients. This research aimed to employ and evaluate several ML algorithms to develop models to quickly predict CKD in patients with T1DM using easily available routine checkup data. This study analyzed 16 years of data of 1375 T1DM patients, obtained from the Epidemiology of Diabetes Interventions and Complications (EDIC) clinical trials directed by the National Institute of Diabetes, Digestive, and Kidney Diseases, USA. Three data imputation techniques (RF, KNN, and MICE) and the SMOTETomek resampling technique were used to preprocess the primary dataset. Ten ML algorithms including logistic regression (LR), k-nearest neighbor (KNN), Gaussian naïve Bayes (GNB), support vector machine (SVM), stochastic gradient descent (SGD), decision tree (DT), gradient boosting (GB), random forest (RF), extreme gradient boosting (XGB), and light gradient-boosted machine (LightGBM) were applied to developed prediction models. Each model included 19 demographic, medical history, behavioral, and biochemical features, and every feature’s effect was ranked using three feature ranking techniques (XGB, RF, and Extra Tree). Lastly, each model’s ROC, sensitivity (recall), specificity, accuracy, precision, and F-1 score were estimated to find the best-performing model. The RF classifier model exhibited the best performance with 0.96 (±0.01) accuracy, 0.98 (±0.01) sensitivity, and 0.93 (±0.02) specificity. LightGBM performed second best and was quite close to RF with 0.95 (±0.06) accuracy. In addition to these two models, KNN, SVM, DT, GB, and XGB models also achieved more than 90% accuracy.

Are the Protean Effects of Pentoxifylline in the Therapy of Diabetes and Its Complications Still Relevant?

Pentoxifylline (Px) has protean effects that can be utilized in the therapy of diabetes and its complications. There have been well-documented but often inconclusive improvements in peripheral arterial disease, foot ulcers, peripheral neuropathy, nephropathy, retinopathy, ischemic heart disease and cerebrovascular disease. In addition, non-alcoholic steatosis and steatohepatitis, which are closely associated with insulin resistance and type 2 diabetes, have been shown to improve with pentoxifylline. Surprisingly, pentoxifylline modestly improves insulin resistance through improvements in capillary blood flow as well as beta cell function and decreased hepatic glucose production. The therapeutic effects of pentoxifylline are complementary to the effects of drugs such as blockers of the renin-angiotensin-aldosterone system when utilized in the therapy of diabetic nephropathy.

Shared parameter and copula models for analysis of semicontinuous longitudinal data with nonrandom dropout and informative censoring

Analysis of longitudinal semicontinuous data characterized by subjects' attrition triggered by nonrandom dropout is complex and requires accounting for the within-subject correlation, and modeling of the dropout process. While methods that address the within-subject correlation and missing data are available, approaches that incorporate the nonrandom dropout, also referred to informative right censoring, in the modeling step are scarce due to the computational intensity and possible intractable integration needed for its implementation. Appreciating the complexity of this problem and the need for a new methodology that is feasible for implementation, we propose to extend a framework of likelihood-based marginalized two-part models to account for informative right censoring. The censoring process is modeled using two approaches: (1) Poisson censoring for the count of visits before dropout and (2) survival time to dropout. Novel consideration was given to the proposed joint modeling approaches for the semicontinuous and censoring components of the likelihood function which included (1) shared parameter, and (2) Clayton copula. The cross-part and within-part correlations were accounted for through a complex random effect structure that models correlated random intercepts and slopes. Feasibility of implementation, and accuracy of these approaches were investigated using extensive simulation studies and clinical application.

Kidney Outcomes Associated With SGLT2 Inhibitors Versus Other Glucose-Lowering Drugs in Real-world Clinical Practice: The Japan Chronic Kidney Disease Database

OBJECTIVE

Randomized controlled trials have shown kidney-protective effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors, and clinical practice databases have suggested that these effects translate to clinical practice. However, long-term efficacy, as well as whether the presence or absence of proteinuria and the rate of estimated glomerular filtration rates (eGFR) decline prior to SGLT2 inhibitor initiation modify treatment efficacy among type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) patients, is unknown.

RESEARCH DESIGN AND METHODS

Using the Japan Chronic Kidney Disease Database (J-CKD-DB), a nationwide multicenter CKD registry, we developed propensity scores for SGLT2 inhibitor initiation, with 1:1 matching with patients who were initiated on other glucose-lowering drugs. The primary outcome included rate of eGFR decline, and the secondary outcomes included a composite outcome of 50% eGFR decline or end-stage kidney disease.

RESULTS

At baseline, mean age at initiation of the SGLT2 inhibitor (n = 1,033) or other glucose-lowering drug (n = 1,033) was 64.4 years, mean eGFR was 68.1 mL/min per 1.73 m², and proteinuria was apparent in 578 (28.0%) of included patients. During follow-up, SGLT2 inhibitor initiation was associated with reduced eGFR decline (difference in slope for SGLT2 inhibitors vs. other drugs 0.75 mL/min/1.73 m² per year [0.51 to 1.00]). During a mean follow-up of 24 months, 103 composite kidney outcomes occurred: 30 (14 events per 1,000 patient-years) among the SGLT2 inhibitors group and 73 (36 events per 1,000 patient-years) among the other drugs group (hazard ratio 0.40, 95% CI 0.26-0.61). The benefit provided by SGLT2 inhibitors was consistent irrespective of proteinuria and rate of eGFR decline before initiation of SGLT2 inhibitors (P _{heterogeneity} ≥ 0.35).

CONCLUSIONS

The benefits of SGLT2 inhibitors on kidney function as observed in clinical trials translate to patients treated in clinical practice with no evidence that the effects are modified by the underlying rate of kidney function decline or the presence of proteinuria.

Serum neutrophil gelatinase-associated lipocalin as a potential biomarker of diabetic kidney disease in patients with childhood-onset type 1 diabetes

BACKGROUND/PURPOSE

Diabetic kidney disease (DKD) is a major complication in patients with type 1 diabetes (T1D). The aim of this study was to evaluate the role of serum neutrophil gelatinase-associated lipocalin (sNGAL) in the early detection of DKD in childhood-onset T1D patients.

METHODS

A total of 116 patients (mean age, 22.3 ± 6.9 years) with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² were enrolled in this prospective cross-sectional study. Persistent albuminuria (PA) was defined as a urine albumin-to-creatinine ratio ≥ 30 mg/g for at least two consecutive years; non-albuminuria (NA) was defined otherwise. The patients were divided into the adult (Ad) (≥18 years, n = 91) and pediatric (Ped) (<18 years, n = 25) groups and further into the Ad-PA (n = 8), Ad-NA (n = 83), Ped-PA (n = 2), and Ad-NA (n = 23) subgroups. In all groups, the sNGAL level was determined.

RESULTS

The mean diabetes duration was 14.2 ± 6.1 years, and 8.6% patients had PA. There was no significant difference in sNGAL levels between the PA and NA groups; notably, in adults, the sNGAL level was significantly higher in the Ad-PA than Ad-NA subgroups (P = 0.039). The sNGAL level was negatively correlated with the eGFR in adults (rho -0.41, P < 0.001). Multiple linear regression models showed that higher sNGAL levels in the adult group were independent and significant determinants of a lower eGFR (P < 0.001).

CONCLUSION

An elevated sNGAL was significantly correlated with a decreased eGFR even in the range of normal to mildly decreased renal function. Thus, it is a potential biomarker of early deterioration of DKD in childhood-onset T1D.

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.

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.

Chronic kidney disease prevalence and cardiovascular risk in a cohort of patients with type 2 diabetes followed for 10 years in Badajoz (Spain). An observational study

AIMS

To estimate the prevalence of chronic kidney disease (CKD), their risk factors the incidence of cardiovascular and coronary events and total and cardiovascular mortality in a cohort of type 2 diabetes (T2DM) patients observed for 10 years in primary care practices in Badajoz, Spain.

METHODS

Observational, longitudinal study. A total of 643 patients with T2DM (mean age 64.0 years, 55.7% women), without evidence of cardiovascular disease, were studied. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² at the beginning of the study, by applying the simplified Modification of Diet in Renal Disease (MDRD) Study formula.

RESULTS

The prevalence rate of CKD was 24.3%. Patients with CKD had higher percentages of coronary, cerebrovascular and cardiovascular events and higher rates of cardiovascular mortality (18.6 vs. 6.0%, p < 0.001) and total mortality (42.3 vs. 23.4%, p < 0.01), compared to patients without CKD. The Cox proportional hazards model, adjusted for age, systolic blood pressure levels, glycated haemoglobin, total cholesterol, obesity and smoking, revealed that patients with CKD had an increased risk of coronary events (HR:2.18; 95% CI:1.13-4.22, p < 0.05).

CONCLUSIONS

Our study confirms a high prevalence of CKD in patients with T2DM and its relationship with the presence of cardiovascular disease.

Non-Albumin Proteinuria (NAP) as a Complementary Marker for Diabetic Kidney Disease (DKD)

Diabetic kidney disease (DKD) is one of the most common forms of chronic kidney disease. Its pathogenic mechanism is complex, and it can affect entire structures of the kidney. However, conventional approaches to early stage DKD have focused on changes to the glomerulus. Current standard screening tools for DKD, albuminuria, and estimated glomerular filtration rate are insufficient to reflect early tubular injury. Therefore, many tubular biomarkers have been suggested. Non-albumin proteinuria (NAP) contains a wide range of tubular biomarkers and is convenient to measure. We reviewed the clinical meanings of NAP and its significance as a marker for early stage DKD.

Assessment of estimated glomerular filtration rate based on cystatin C in diabetic nephropathy

Introduction:

GFR is estimated by using creatinine and cystatin C to determine renal dysfunction. Our aim was to evaluate estimated GFR (eGFR) based on cystatin C in type 2 diabetic patients with diabetic nephropathy (DN).

Methods:

Study group included 52 controls (46% male, age: 54.5±12.4) and 101 diabetic patients (46.5% male, age: 58.2±11). The diabetics were divided into three subgroups according to 24-hour urine albumin: normal to mildly increased (A1) (n=51), moderately increased (A2) (n=25), severely increased (A3) (n=25) albuminuria. Creatinine clearance (CrCl) was determined. Correlations between CrCl and eGFRs estimated according to the CKD-EPI, MDRD, and Cockcroft-Gault (CG) formulas, and ROC curves were evaluated. Data were analyzed using SPSS 22.0.

Results:

Only CKD-EPI-cys eGFR was significantly lower in the A1 group than the controls (p=0.021). All GFRs were lower in the A3 group than the control (CKD-EPI-cr, MDRD, CKD-EPI-cys, CKD-EPI-cr-cys: p=0.0001, CG and CrCl: p=0.001) and A1 (for all GFRs p=0.0001) groups. CKD-EPI-cr (p=0.004), MDRD (p=0.01), CG (p=0.037), CKD-EPI-cys (p=0.033), and CKD-EPI-cr-cys (p=0.016) eGFRs in the A2 group were significantly different from the A1 group. All eGFRs showed a moderate correlation with CrCl in the A1group (CKD-EPI-cr and CKD-EPI-cr-cys: r=0.49, p=0.0001, MDRD: r=0.44, p=0.001, CG r=0.48, p=0.0001: CKD-EPI-cys r=0.40, p=0.004). The area under the CKD-EPI-cys ROC curve was the highest and found to be 0.847 (95%CI 0.763-0.931, p=0.0001).

Conclusions:

Our results showed that the CKD-EPI-cys eGFR can be useful in detecting the early stage of DN and more predictive than the others for prediction of DN.

11. Microvascular Complications and Foot Care: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Current Challenges and Future Perspectives of Renal Tubular Dysfunction in Diabetic Kidney Disease

Over decades, substantial progress has been achieved in understanding the pathogenesis of proteinuria in diabetic kidney disease (DKD), biomarkers for DKD screening, diagnosis, and prognosis, as well as novel hypoglycemia agents in clinical trials, thereby rendering more attention focused on the role of renal tubules in DKD. Previous studies have demonstrated that morphological and functional changes in renal tubules are highly involved in the occurrence and development of DKD. Novel tubular biomarkers have shown some clinical importance. However, there are many challenges to transition into personalized diagnosis and guidance for individual therapy in clinical practice. Large-scale clinical trials suggested the clinical relevance of increased proximal reabsorption and hyperfiltration by sodium-glucose cotransporter-2 (SGLT2) to improve renal outcomes in patients with diabetes, further promoting the emergence of renal tubulocentric research. Therefore, this review summarized the recent progress in the pathophysiology associated with involved mechanisms of renal tubules, potential tubular biomarkers with clinical application, and renal tubular factors in DKD management. The mechanism of kidney protection and impressive results from clinical trials of SGLT2 inhibitors were summarized and discussed, offering a comprehensive update on therapeutic strategies targeting renal tubules.

Clinical and Pathological Characteristics of Patients With Nonproteinuric Diabetic Nephropathy

INTRODUCTION

As the most common complication of diabetes mellitus (DM), diabetic nephropathy (DN) was initially considered to begin with proteinuria preceding the progression of renal insufficiency. This clinical paradigm has been questioned in the late decades, as many DM patients without proteinuria have progressive renal insufficiency. However, the characteristics of nonproteinuric DN were not fully clear yet.

PATIENTS AND METHODS

A total of 390 patients with renal biopsy-proven DN in our center were retrospectively recruited in the current study. Clinical and histopathological data of the patients were analyzed. We used propensity score-matching methods to address the imbalance of age, sex, and diabetes duration for comparative analyses.

RESULTS

Among all the renal biopsy-proven DN patients with renal biopsy proven DN, 18 patients were classified as nonproteinuric DN. Compared with 36 propensity score-matched proteinuric DN patients, diabetic retinopathy (DR) was less frequent in nonproteinuric DN patients (38.9% vs. 66.4%, p<0.05). During the follow-up of 24.0 (12.0-42.0) months, the probability of developing the end-stage renal disease (ESRD) was significantly lower in nonproteinuric DN patients than in proteinuric ones in both the propensity score-matched cohort and overall cohort (log-rank test, p<0.001 and p<0.001, respectively).

CONCLUSIONS

Compared with proteinuric DN patients, DR was less frequent in nonproteinuric DN patients. Nonproteinuric DN patients had better renal outcomes than proteinuric DN patients.

Risk Prediction of the Diabetes Missing Million: Identifying Individuals at High Risk of Diabetes and Related Complications

Early diagnosis and effective management of type 2 diabetes (T2D) are crucial in reducing the risk of developing life-changing complications such as heart failure, stroke, kidney disease, blindness and amputation, which are also associated with significant costs for healthcare providers. However, as T2D symptoms often develop slowly it is not uncommon for people to live with T2D for years without being aware of their condition-commonly known as the undiagnosed missing million. By the time a diagnosis is received, many individuals will have already developed serious complications. While the existence of undiagnosed diabetes has long been recognised, wide-reaching awareness among the general public, clinicians and policymakers is lacking, and there is uncertainty in how best to identify high-risk individuals. In this article we have used consensus expert opinion alongside the available evidence, to provide support for the diabetes healthcare community regarding risk prediction of the missing million. Its purpose is to provide awareness of the risk factors for identifying individuals at high, moderate and low risk of T2D and T2D-related complications. The awareness of risk predictors, particularly in primary care, is important, so that appropriate steps can be taken to reduce the clinical and economic burden of T2D and its complications.

Type 2 diabetes mellitus management in patients with chronic kidney disease: an update

Diabetes mellitus (DM) is a chronic multisystem disease. Diabetic nephropathy (DN) is one of its significant microvascular complications, associated with increased morbidity and mortality. The aim of this article is to review the literature regarding the latest advances in the management of type 2 DM (T2DM) in patients with chronic kidney disease (CKD). We initially refer to the screening guidelines, the diagnostic tests used, the need for novel biomarkers in DN, the recent advances in high-risk patient identification, the recommended glycemic targets, and concerns regarding the accuracy of HbA1c in these patients. Then, a detailed explanation of the appropriate medical management based on evidence from recent trials is presented, analyzed, and discussed. All patients with T2DM should be screened for albuminuria at initial diagnosis and annually thereafter. Proteomics and metabolomics today represent promising diagnostic tools. Optimal glycemic control, with individualized HbA1c targets, is fundamental for reduced onset or delayed progression of DN and microvascular complications, in general. This can be enhanced by lifestyle modifications and pharmacological interventions when needed. Metformin represents the first pharmacological step, with, recently, a broadened indication for patients with impaired renal function. If HbA1c remains above the target in patients with established CKD, SGLT2i or GLP-1 RA are the preferred second-line agents, as introduced in all new guidelines. This change was the result of recent landmark trials that highlighted the superiority of the two aforementioned medication categories in terms of both renal and cardiovascular outcomes.

Association of parameters of nocturnal hypoxemia with diabetic microvascular complications: A cross-sectional study

AIMS

To examine the association between obstructive sleep apnea (OSA)-related nocturnal hypoxemia parameters and diabetic microvascular complications in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 463 Chinese patients with T2DM underwent overnight polysomnography, followed by diagnosis of diabetic microvascular complications including diabetic peripheral neuropathy (DPN), diabetic retinopathy (DR) and diabetic nephropathy (DN). Parameters of nocturnal hypoxemia, including apnea-hypopnea index (AHI), oxygen desaturation index (ODI), time spent with SpO₂ < 90% (T90%) or <85% (T85%), mean SpO₂ and lowest SpO₂, were recorded.

RESULTS

AHI was independently associated with higher odds of DPN (OR 1.19; 95% CI, 1.05-1.36; P = 0.008) after adjustment for possible confounders. Moreover, patients with severe OSA (AHI ≥ 30 events/h) had higher likelihood of having DPN than those with mild OSA (OR 2.36; 95% CI, 1.31-4.25; P = 0.004). When combining DPN, DR and DN into an overall diabetic microvascular complication index, AHI was also independently associated with higher odds of having any diabetic microvascular complication (OR 1.21; 95% CI, 1.06-1.38; P = 0.006).

CONCLUSIONS

The AHI may be the OSA-related index that most strongly reflects the association of OSA and diabetic microvascular complications, compared with other OSA-related hypoxemia parameters.

Neutrophil count as a reliable marker for diabetic kidney disease in autoimmune diabetes

BACKGROUND

A growing body of evidence supports neutrophils as having an active role in the development of diabetic kidney disease (DKD). However, the clinical relevance of neutrophils and DKD in autoimmune diabetes remains unknown. This study aimed to investigate the relationship between circulating neutrophils and DKD in autoimmune diabetes.

METHODS

Patients with type 1 diabetes (T1D, n = 226) and latent autoimmune diabetes in adults (LADA, n = 79) were enrolled and stratified according to the urinary albumin to creatinine ratio (ACR). Circulating levels of white blood cells (WBCs), including neutrophils, were measured in a central laboratory, and the neutrophil-to-lymphocyte ratio (NLR) was calculated. The risk factors associated with DKD were analysed by logistic regression.

RESULTS

In T1D and LADA patients, the peripheral neutrophil counts increased in parallel with DKD advancement. The neutrophil counts in the patients with macroalbuminuria were significantly higher than those in the patients with normoalbuminuria for each type of diabetes. Furthermore, neutrophil counts positively correlated with ACR in T1D. In addition, neutrophils were independently associated with DKD in T1D in the logistic regression analysis, when various well-known risk factors, including age, gender, disease duration, hypertension, dyslipidemia and smoking status, were adjusted.

CONCLUSIONS

Neutrophil counts are closely associated with DKD in patients with autoimmune diabetes, suggesting that neutrophil-mediated inflammation may be involved in the pathogenesis of DKD in patients with autoimmune diabetes.

Urinary angiotensinogen antedates the development of stage 3 CKD in patients with type 1 diabetes mellitus

We examined if urinary angiotensinogen (uAOG), a marker of intrarenal renin‐angiotensin system activity, antedates stage 3 chronic kidney disease (CKD) using samples from participants in the Diabetes Control and Complications Trial (DCCT) and later in the Epidemiology of Diabetes Intervention and Complications (EDIC) trial. In a nested case–control design, cases were matched at the outcome visit (eGFR less than 60, 21‐59 mL/min per 1.73 m²) on age, gender, and diabetes duration, with controls: eGFR (95, 75‐119, mL/min per 1.73 m².) Additionally, in an exploratory analysis progressive renal decline (PRD), defined as eGFR loss >3.5 mL/min per 1.73m²/year, was evaluated using only data from EDIC because no progressions were observed during DCCT. At the EDIC visit, which antedated the GFR outcome visit by 2 years (range 1–7years) the median uAOG/creatinine was markedly higher in cases than in controls (13.9 vs. 3.8 ng/mg P = 0.003) whereas at the DCCT visit, which antedated the GFR outcome by 17 to 20 years it was not (2.75 vs. 3.16 ng/mg, respectively). The Odds Ratio for uAOG and CKD stage 3 development was significant after adjusting for eGFR, HbA1c, and systolic blood pressure 1.82 (1.00–3.29) but no longer significant when Albumin Excretion Ratio (AER) was included 1.21 (0.65–2.24).In the PRD analysis, uAOG/creatinine was sixfold higher in participants who experienced PRD than in those who did not (26 vs. 4.0 ng/mg, P = 0.003). The Odds Ratio for uAOG and PRD was significant after adjusting for eGFR, HbA1c, and systolic blood pressure 2.48 (1.46–4.22) but no longer significant when AER was included 1.32 (0.76–2.30). In people with type1 diabetes, a robust increase in uAOG antedates the development of stage 3 CKD but is not superior to AER in predicting this renal outcome. Increased uAOG moreover is associated with PRD, an index of progression to End Stage Kidney Disease (ESKD).

Renal function deterioration in adult patients with type-2 diabetes

BACKGROUND

To explore, in a large group of patients with type-2 diabetes (T2DM), renal function decline in terms of the slope of the estimated glomerular filtration rate (eGFR) over time, and to find out how classical risk factors, such as the presence of hypertension, dyslipidemia and microalbuminuria, affect the renal function.

METHODS

The analysis included 32,492 adult T2DM patients from the DIVE/DPV registries who had serial eGFR determinations and information on the presence of microalbuminuria, hypertension and dyslipidemia available.

RESULTS

Patients had a mean age of 66.3 years, 52.6% were male with a mean BMI of 31.7 kg/m2. The mean eGFR was 78.4 ± 21.4 mL/min/1.73m2. The results showed that the prevalence of renal function impairment understood as chronic kidney disease (CKD) is considerable (53.0%) in a population of patients with T2DM and has a high incidence rate of 6.6% within a year. Serial determinations of the eGFR are, however, infrequent (7.8% of all patients) and these patients are characterised by the presence of a high-risk profile for CKD, such as hypertension (88.1%) and dyslipidemia (66.1%). Over a three-year time period, 30.9% of the patients had an eGFR slope of -12 mL/min/1.73m2 or more; and more than a doubled proportion of patients with an eGFR < 30 mL/min/1.73 m2 (3.8% vs. 1.8%; p < 0.001). Hypertension and albuminuria contributed to renal function decline while dyslipidemia did not negatively affect the slope.

CONCLUSION

CKD is highly prevalent in patients with T2DM. Serial surveillance of the glomerular filtration rate is, however, not established in clinical practice, which would be necessary as indicated by a doubling of patients with an eGFR < 30 mL/min/1.73 m2 within 3 years. Moreover, the use of renin-angiotensin blocking agents was low, pointing at considerable room for improvement. Taken together we conclude that a closer surveillance of patients with diabetes based on the presence of further risk factors is mandatory combined with a mandatory prescription of RAS blocking agents once microalbuminuria and / or renal function deterioration develops.

When ESKD complicates the management of diabetes mellitus

Given the increased incidence and prevalence of ESKD (end-stage kidney disease) attributed to diabetes mellitus, it is important to consider the physiological and global sociodemographic factors that give rise to unique challenges in providing excellent care to this population. The individual with diabetes and ESKD faces alterations of glucose homeostasis that require close therapeutic attention, as well as the consideration of safe and effective means of maintaining glycemic control. Implementation of routine monitoring of blood glucose and thoughtful alteration of the individual's hypoglycemic drug regimen must be employed to reduce the risk of neurological, cardiovascular, and diabetes-specific complications that may arise as a result of ESKD. Titration of insulin therapy may become quite challenging, as kidney replacement therapy often significantly impacts insulin requirements. New medications have significantly improved the ability of the clinician to provide effective therapies for the management of diabetes, but have also raised an equal amount of uncertainty with respect to their safety and efficacy in the ESKD population. Additionally, the clinician must consider the challenges related to the delivery of kidney replacement therapy, and how inter-modality differences may impact glycemic control, diabetes, and ESKD-related complications, and issues surrounding dialysis vascular access creation.

An updated overview of diabetic nephropathy: Diagnosis, prognosis, treatment goals and latest guidelines

Diabetic nephropathy (DN) is a major healthcare challenge. It occurs in up to 50% of those living with diabetes, is a major cause of end-stage kidney disease (ESKD) that requires treatment with dialysis or renal transplantation, and is associated with significantly increased cardiovascular morbidity and mortality. DN is a clinical syndrome characterized by persistent albuminuria and a progressive decline in renal function, but it is increasingly recognized that the presentation and clinical course of kidney disease in diabetes is heterogeneous. The term diabetic kidney disease (DKD) is now commonly used to encompass the spectrum of people with diabetes who have either albuminuria or reductions in renal function. In this article, the clinical presentation and approach to diagnosis of DKD will be discussed, as will its prognosis. The general principles of management of DKD will also be reviewed with reference to current international guidelines.

Nonproteinuric diabetic kidney disease

Proteinuria has been considered to be the hallmark of diabetic kidney disease and to precede renal function loss. However, it has become clear that a substantial proportion of patients either with type 1 diabetes or type 2 diabetes have renal function loss without proteinuria, known as nonproteinuric diabetic kidney disease. Despite increasing recognition of the prevalence of nonproteinuric diabetic kidney disease, data on this phenotype of diabetic kidney disease is sparse. This review describes ever known clinical and pathological manifestations, renal prognosis, and mortality in patient with nonproteinuric diabetic kidney disease.

Changes in Albuminuria But Not GFR are Associated with Early Changes in Kidney Structure in Type 2 Diabetes

BACKGROUND

In type 1 diabetes, changes in the GFR and urine albumin-to-creatinine ratio (ACR) are related to changes in kidney structure that reflect disease progression. However, such changes have not been studied in type 2 diabetes.

METHODS

Participants were American Indians with type 2 diabetes enrolled in a clinical trial of losartan versus placebo. We followed a subset who underwent kidney biopsy at the end of the 6-year trial, with annual measurements of GFR (by urinary clearance of iothalamate) and ACR. Participants had a second kidney biopsy after a mean follow-up of 9.3 years. We used quantitative morphometric analyses to evaluate both biopsy specimens.

RESULTS

Baseline measures for 48 participants (12 men and 36 women, mean age 45.6 years) who completed the study included diabetes duration (14.6 years), GFR (156 ml/min), and ACR (15 mg/g). During follow-up, glomerular basement membrane (GBM) width, mesangial fractional volume, and ACR increased, and surface density of peripheral GBM and GFR decreased. After adjustment for sex, age, ACR, and each morphometric variable at baseline, an increase in ACR during follow-up was significantly associated with increases in GBM width, mesangial fractional volume, and mean glomerular volume, and a decrease in surface density of peripheral GBM. Decline in GFR was not associated with changes in these morphometric variables after additionally adjusting for baseline GFR.

CONCLUSIONS

In American Indians with type 2 diabetes and preserved GFR at baseline, increasing ACR reflects the progression of earlier structural glomerular lesions, whereas early GFR decline may not accurately reflect such lesions.