Risk factors for the development of albuminuria and renal impairment in type 2 diabetes--the Swedish National Diabetes Register (NDR)

Nomenclature of renal involvement in diabetes mellitus: unify to manage diversity

Diabetes mellitus is the most common cause of chronic kidney disease leading to kidney failure and premature death. Over the years, the nomenclature of kidney involvement in diabetes mellitus has evolved, driven both by the understanding that the phenotype may be more diverse than initially thought and by pragmatism. In clinical practice, most patients with diabetes mellitus do not undergo a comprehensive work-up (including kidney biopsy and genetic testing) to exclude the presence or coexistence of additional factors or other kidney diseases. Furthermore, the inclusion criteria for successful kidney protection clinical trials that are the basis of current guidelines covered a wide range of kidney phenotypes under the label of "diabetes and kidney disease," without requiring proactive efforts to exclude other nephropathies. The aim of this review is to provide a critical review of the most common chronic kidney disease phenotypes in the context of diabetes mellitus and discuss the evolving nomenclature. Various topics are discuss diabetic kidney disease, classic diabetic nephropathy, regression of albuminuria, rapid progression, non-albuminuric and non-proteinuric kidney disease, the connections between and the impact of aging on these phenotypes and a glimpse into future phenotypes resulting from proactive prevention rather than reactive treatment of kidney disease in diabetes.

Risk of onset of chronic kidney disease in type 2 diabetes mellitus (ROCK-DM): Development and validation of a 4-variable prediction model

AIMS

The aim of this study was to develop and validate a prediction model for incident chronic kidney disease (CKD) in type 2 diabetes mellitus (T2DM), defined as eGFR < 60 ml/min/1.73m2 and/or urine albumin:creatinine ratio (UACR) > 3 mg/mmol in ≥ 2 consecutive readings ≥ 3 months apart.

METHODS

Model derivation was performed in the SingHealth Diabetes Registry, including patients aged ≥ 21 years diagnosed with T2DM without pre-existing CKD. External validation was performed in a single-center prospective observational cohort. Cox Proportional Hazard model was created to evaluate predictors associated with time-to-onset of incident CKD. Increasingly parsimonious models were assessed for discrimination and calibration. Models underwent external validation, benchmarking against existing models, and decision curve analysis.

RESULTS

25,142 (59 %) of 42,552 patients in the derivation cohort developed CKD over a median 4.0 years (IQR 2.1-7.7) follow up. An 18-variable model, 12-variable model, and 4-variable model (including age, duration of T2DM, eGFR, and previous non-persistent albuminuria) was developed. The 4-variable model had a C-statistic of 0.78 and good calibration on plots of observed-versus-predicted risk. The 12-variable and 18-variable models performed similarly. In the external validation cohort of 2249 patients, of whom 1035 (46 %) developed incident CKD, the 4-variable model had a C-statistic of 0.87. All models had better discrimination than existing benchmarks. Decision curve analysis of the 4-variable model showed positive net benefit for any threshold probability above 16 % for 2-year and 28 % for 5-year CKD risk.

CONCLUSION

The 4-variable model for prediction of incident CKD in T2DM demonstrates good performance, predicts both eGFR and albuminuria endpoints, and is simple-to-use. This may guide personalized care, resource allocation and population health.

Risk factors for rapid kidney function decline in diabetes patients

Diabetic nephropathy, as a severe microvascular complication of diabetes, manifests in four clinical types: classic, albuminuria regression, a rapid decline in kidney function (RDKF), and non-proteinuric or non-albuminuric DKD. Rapidly progressive diabetic nephropathy advances to end-stage renal disease more swiftly than the typical form, posing significant risks. However, a comprehensive understanding of rapidly progressive diabetic nephropathy is currently lacking. This article reviewed latest developments in genetic and clinical risk factors associated with rapidly progressive diabetic nephropathy, aiming to broad perspectives concerning the diagnosis and interventions of this condition.

Prevalence of Chronic Kidney Disease and Associated Factors among the Diabetic and Prediabetic Population in the Bandare-Kong Cohort Study; A Population-Based Study

BACKGROUND

This investigation aims to examine the relationship between diabetes and prediabetes with chronic kidney disease (CKD) while taking into account key risk factors such as gender, age, lifestyle, smoking habits, and blood pressure.

METHODS

Between November 17, 2016, and November 22, 2018, 4063 subjects aged 35 to 70 years were enrolled in the first phase of the Bandare-Kong Non-Communicable Disease (BKNCD) Cohort Study, which is part of the PERSIAN (Prospective Epidemiological Research Studies in IrAN) cohort and was conducted in a coastal region of the Hormozgan province in southern Iran. CKD was calculated using the Modification of Diet in Renal Disease (MDRD) formula based on glomerular filtration rate (GFR)<60 mL/min per 1.73 m2 , or albumin/Cr>30 mg/g in random urine, self-reported kidney failure, or dialysis. Urine albumin and creatinine were determined by standard kits (Pars Azmoon, Tehran, Iran) and the BT1500 automatic chemistry analyzer (Biotecnica Instruments, Rome, Italy).

RESULTS

The prevalence of CKD was found to be 15.3%, with 29.6% identified in diabetic individuals and 16.5% in prediabetic patients. So, the prevalence of CKD in diabetics was higher than prediabetics and normal people. Increased age, dysglycemia (diabetes or prediabetes), hypertension, and use of angiotensin receptor blockers were markedly associated with an elevated risk of CKD in adults.

CONCLUSION

The study emphasizes the importance of early detection and management of CKD risk factors, particularly among high-risk individuals, to mitigate CKD progression and associated complications. By addressing modifiable risk factors, proactive screening, and enhanced awareness, significant strides can be made in reducing CKD burden and improving patient outcomes.

Machine Learning Models for Prediction of Diabetic Microvascular Complications

IMPORTANCE AND AIMS

Diabetic microvascular complications significantly impact morbidity and mortality. This review focuses on machine learning/artificial intelligence (ML/AI) in predicting diabetic retinopathy (DR), diabetic kidney disease (DKD), and diabetic neuropathy (DN).

METHODS

A comprehensive PubMed search from 1990 to 2023 identified studies on ML/AI models for diabetic microvascular complications. The review analyzed study design, cohorts, predictors, ML techniques, prediction horizon, and performance metrics.

RESULTS

Among the 74 identified studies, 256 featured internally validated ML models and 124 had externally validated models, with about half being retrospective. Since 2010, there has been a rise in the use of ML for predicting microvascular complications, mainly driven by DKD research across 27 countries. A more modest increase in ML research on DR and DN was observed, with publications from fewer countries. For all microvascular complications, predictive models achieved a mean (standard deviation) c-statistic of 0.79 (0.09) on internal validation and 0.72 (0.12) on external validation. Diabetic kidney disease models had the highest discrimination, with c-statistics of 0.81 (0.09) on internal validation and 0.74 (0.13) on external validation, respectively. Few studies externally validated prediction of DN. The prediction horizon, outcome definitions, number and type of predictors, and ML technique significantly influenced model performance.

CONCLUSIONS AND RELEVANCE

There is growing global interest in using ML for predicting diabetic microvascular complications. Research on DKD is the most advanced in terms of publication volume and overall prediction performance. Both DR and DN require more research. External validation and adherence to recommended guidelines are crucial.

Renal safety of zoledronic acid in patients with osteoporosis: a retrospective study

INTRODUCTION

This study aimed to investigate the renal safety of Zoledronic Acid (ZOL) in patients with osteoporosis (OP).

METHODS

A total of 1379 patients (baseline estimated glomerular filtration rate, eGFR ≥ 60 mL/min/1.73 m2) with primary OP who received ZOL from January 2008 to October 2020 at our hospital were retrospectively analyzed. Baseline and the changes in renal function within 1 year following infusions were collected, the incidence of renal impairment (eGFR < 60 mL/min/1.73 m2 or a > 25% reduction in the eGFR from baseline) was noted and the risk factors were analyzed. Furthermore, the changes in renal function between a 3-year consecutive infusion and a single infusion of ZOL were compared.

RESULTS

Renal impairment occurred in 8.05% of patients, who with a significantly higher age, Charlson Comorbidity Index (CCI), smoking history, combination of hypertension or diabetes mellitus and worse renal function indicators (all P < 0.05). Binary logistic regression analysis showed that higher CCI (≥5) or smoking history or the baseline eGFR <90 mL/min/1.73 m2 were the risk factors for renal impairment (all P < 0.05). Patients of 3-year continuous infusion group had a significantly greater drop in the eGFR levels than the single infusion group after 1 year of infusion(s) (P < 0.05).

CONCLUSION

Attention should be given to possible potential renal impairment following ZOL infusion in clinical practice for the management of OP, particularly in patients with higher CCI (≥5) or smoking history or the baseline eGFR <90 mL/min/1.73 m2. Continuous infusion of ZOL exerts a significant impact on renal function when compared to single infusion and intensive monitoring of renal function is necessary.

Relationship of cardiorenal risk factors with albuminuria based on age, smoking, glycaemic status and BMI: a retrospective cohort study of the UK Biobank data

Introduction

Smoking is harmful, and its cessation is recommended to prevent chronic kidney disease, which often begins with abnormal leakage of albumin in the urine, called albuminuria. Smoking cessation's effect on albuminuria depends on the pack-years smoked, length of abstinence, body mass index (BMI) and glycosylated haemoglobin (HbA1c). Using the UK Biobank data, we examined the relationship between these cardiorenal variables and albuminuria.

Methods

For this study, we selected a UK Biobank cohort with urinary albumin concentration (UAC) in the first and second visits. Participants were divided into progressor and regressor groups, where progressors were defined as those with increased UAC value, and regressors were those with decreased UAC value. Three different logistic regression models were fitted. In model 1, with a cohort design, we explored the impact of a change in age, HbA1c and BMI between the first and second visits and the UAC. In model 2 and 3, in a cross-sectional design, we explored which cardiorenal risk factors were associated with a rise or fall of UAC at the time point of the second visit. Results are expressed in OR and 95% CI.

Results

The prevalence of albuminuria was highest in ex-smokers who started smoking between the ages of 13 and 18. With a mean duration of 51 months, there was no statistically significant relationship between smoking status and BMI with albuminuria. Each year of ageing and each unit of increase in HbA1c (mmol/mol) increased the odds of progression of albuminuria by 20% and 3%, respectively. In ex-smokers, at the time point of the second visit, each year of smoking increased, and each year of abstinence decreased the odds by 4% and 6%, respectively.

Conclusion

Smokers should be supported to stop smoking and remain abstinent despite short-term weight gain. Childhood smoking should be actively discouraged.

Validation of a risk prediction model for early chronic kidney disease in patients with type 2 diabetes: Data from the German/Austrian Diabetes Prospective Follow-up registry

AIM

To validate a recently proposed risk prediction model for chronic kidney disease (CKD) in type 2 diabetes (T2D).

MATERIALS AND METHODS

Subjects from the German/Austrian Diabetes Prospective Follow-up (DPV) registry with T2D, normoalbuminuria, an estimated glomerular filtration rate of 60 ml/min/1.73m² or higher and aged 39-75 years were included. Prognostic factors included age, body mass index (BMI), smoking status and HbA1c. Subjects were categorized into low, moderate, high and very high-risk groups. Outcome was CKD occurrence.

RESULTS

Subjects (n = 10 922) had a mean age of 61 years, diabetes duration of 6 years, BMI of 31.7 kg/m² , HbA1c of 6.9% (52 mmol/mol); 9.1% had diabetic retinopathy and 16.3% were smokers. After the follow-up (~59 months), 37.4% subjects developed CKD. The area under the curve (AUC; unadjusted base model) was 0.58 (95% CI 0.57-0.59). After adjustment for diabetes and follow-up duration, the AUC was 0.69 (95% CI 0.68-0.70), indicating improved discrimination. After follow-up, 15.0%, 20.1%, 27.7% and 40.2% patients in the low, moderate, high and very high-risk groups, respectively, had developed CKD. Increasing risk score correlated with increasing cumulative risk of incident CKD over a median of 4.5 years of follow-up (P < .0001).

CONCLUSIONS

The predictive model achieved moderate discrimination but good calibration in a German/Austrian T2D population, suggesting that the model may be relevant for determining CKD risk.

Identifying myoglobin as a mediator of diabetic kidney disease: a machine learning-based cross-sectional study

In view of the alarming increase in the burden of diabetes mellitus (DM) today, a rising number of patients with diabetic kidney disease (DKD) is forecasted. Current DKD predictive models often lack reliable biomarkers and perform poorly. In this regard, serum myoglobin (Mb) identified by machine learning (ML) may become a potential DKD indicator. We aimed to elucidate the significance of serum Mb in the pathogenesis of DKD. Electronic health record data from a total of 728 hospitalized patients with DM (286 DKD vs. 442 non-DKD) were used. We developed DKD ML models incorporating serum Mb and metabolic syndrome (MetS) components (insulin resistance and β-cell function, glucose, lipid) while using SHapley Additive exPlanation (SHAP) to interpret features. Restricted cubic spline (RCS) models were applied to evaluate the relationship between serum Mb and DKD. Serum Mb-mediated renal function impairment induced by MetS components was verified by causal mediation effect analysis. The area under the receiver operating characteristic curve of the DKD machine learning models incorporating serum Mb and MetS components reached 0.85. Feature importance analysis and SHAP showed that serum Mb and MetS components were important features. Further RCS models of DKD showed that the odds ratio was greater than 1 when serum Mb was > 80. Serum Mb showed a significant indirect effect in renal function impairment when using MetS components such as HOMA-IR, HGI and HDL-C/TC as a reason. Moderately elevated serum Mb is associated with the risk of DKD. Serum Mb may mediate MetS component-caused renal function impairment.

A prediction model to assess the risk of egfr loss in patients with type 2 diabetes and preserved kidney function: The amd annals initiative

OBJECTIVE

To develop and validate a model for predicting 5-year eGFR-loss in type 2 diabetes mellitus (T2DM) patients with preserved renal function at baseline.

RESEARCH DESIGN AND METHODS

A cohort of 504.532 T2DM outpatients participating to the Medical Associations of Diabetologists (AMD) Annals Initiative was splitted into the Learning and Validation cohorts, in which the predictive model was respectively developed and validated. A multivariate Cox proportional hazard regression model including all baseline characteristics was performed to identify predictors of eGFR-loss. A weight derived from regression coefficients was assigned to each variable and the overall sum of weights determined the 0 to 8-risk score.

RESULTS

A set of demographic, clinical and laboratory parameters entered the final model. The eGFR-loss score showed a good performance in the Validation cohort. Increasing score values progressively identified a higher risk of GFR loss: a score ≥ 8 was associated with a HR of 13.48 (12.96-14.01) in the Learning and a HR of 13.45 (12.93-13.99) in the Validation cohort. The 5 years-probability of developing the study outcome was 55.9% higher in subjects with a score ≥ 8.

CONCLUSIONS

In the large AMD Annals Initiative cohort, we developed and validated an eGFR-loss prediction model to identify T2DM patients at risk of developing clinically meaningful renal complications within a 5-years time frame.

Range of Risk Factor Levels, Risk Control, and Temporal Trends for Nephropathy and End-stage Kidney Disease in Patients With Type 1 and Type 2 Diabetes

OBJECTIVE

To investigate trends, optimal levels for cardiometabolic risk factors, and multifactorial risk control in diabetic nephropathy and end-stage kidney disease (ESKD) in patients with diabetes and matched control subjects.

RESEARCH DESIGN AND METHODS

This study included 701,622 patients with diabetes from the Swedish National Diabetes Register and 2,738,137 control subjects. Trends were analyzed with standardized incidence rates. Cox regression was used to assess excess risk, optimal risk factor levels, and risk according to the number of risk factors, in diabetes.

RESULTS

ESKD incidence among patients with and without diabetes initially declined until 2007 and increased thereafter, whereas diabetic nephropathy decreased throughout follow-up. In patients with diabetes, baseline values for glycated hemoglobin, systolic blood pressure (SBP), triglycerides, and BMI were associated with outcomes. Hazard ratio (HR) for ESKD for patients with type 2 diabetes who had all included risk factors at target was 1.60 (95% CI 1.49-1.71) compared with control subjects and for patients with type 1 diabetes 6.10 (95% CI 4.69-7.93). Risk for outcomes increased in a stepwise fashion for each risk factor not at target. Excess risk for ESKD in type 2 diabetes showed a HR of 2.32 (95% CI 2.30-2.35) and in type 1 diabetes 10.92 (95% CI 10.15-11.75), compared with control.

CONCLUSIONS

Incidence of diabetic nephropathy has declined substantially, whereas ESKD incidence has increased. Traditional and modifiable risk factors below target levels were associated with lower risks for outcomes, particularly notable for the causal risk factors of SBP and HbA1c, with potential implications for care.

Nonalbuminuric Diabetic Kidney Disease and Risk of All-Cause Mortality and Cardiovascular and Kidney Outcomes in Type 2 Diabetes: Findings From the Hong Kong Diabetes Biobank

RATIONALE & OBJECTIVE

Nonalbuminuric diabetic kidney disease (DKD) has become the prevailing DKD phenotype. We compared the risks of adverse outcomes among patients with this phenotype compared with other DKD phenotypes.

STUDY DESIGN

Multicenter prospective cohort study.

SETTINGS & PARTICIPANTS

19,025 Chinese adults with type 2 diabetes enrolled in the Hong Kong Diabetes Biobank.

EXPOSURES

DKD phenotypes defined by baseline estimated glomerular filtration rate (eGFR) and albuminuria: no DKD (no decreased eGFR or albuminuria), albuminuria without decreased eGFR, decreased eGFR without albuminuria, and albuminuria with decreased eGFR.

OUTCOMES

All-cause mortality, cardiovascular disease (CVD) events, hospitalization for heart failure (HF), and chronic kidney disease (CKD) progression (incident kidney failure or sustained eGFR reduction ≥40%).

ANALYTICAL APPROACH

Multivariable Cox proportional or cause-specific hazards models to estimate the relative risks of death, CVD, hospitalization for HF, and CKD progression. Multiple imputation was used for missing covariates.

RESULTS

Mean participant age was 61.1 years, 58.3% were male, and mean diabetes duration was 11.1 years. During 54,260 person-years of follow-up, 438 deaths, 1,076 CVD events, 298 hospitalizations for HF, and 1,161 episodes of CKD progression occurred. Compared with the no-DKD subgroup, the subgroup with decreased eGFR without albuminuria had higher risks of all-cause mortality (hazard ratio [HR], 1.59 [95% CI, 1.04-2.44]), hospitalization for HF (HR, 3.08 [95% CI, 1.82-5.21]), and CKD progression (HR, 2.37 [95% CI, 1.63-3.43]), but the risk of CVD was not significantly greater (HR, 1.14 [95% CI, 0.88-1.48]). The risks of death, CVD, hospitalization for HF, and CKD progression were higher in the setting of albuminuria with or without decreased eGFR. A sensitivity analysis that excluded participants with baseline eGFR <30 mL/min/1.73 m² yielded similar findings.

LIMITATIONS

Potential misclassification because of drug use.

CONCLUSIONS

Nonalbuminuric DKD was associated with higher risks of hospitalization for HF and of CKD progression than no DKD, regardless of baseline eGFR.

Elevated One-Hour Post-Load Glucose Is Independently Associated with Albuminuria: A Cross-Sectional Population Study

The purpose of this study was to examine and compare the associations between albuminuria and fasting (FPG), 1 h post-load (1 h PG) and 2 h post-load plasma glucose (2 h PG) in an oral glucose tolerance test (OGTT). A total of 496 people free of known diabetes (mean age 72 years) participated in the examinations including the OGTT with plasma glucose measurements at 0, 1, and 2 h and levels of HbA1c. Albuminuria was determined by the urinary albumin-to-creatinine ratio and was defined as ≥3.0 mg/mmol. Compared with those without albuminuria, participants with albuminuria had significantly higher 1 h PG and 2 h PG levels, but not FPG or HbA1c levels. An elevated 1 h PG increased the estimated odds ratio of albuminuria more than three times in people with prediabetic 1 h PG (8.6–11.5 mmol/L: OR 3.60; 95% CI 1.70–7.64) and diabetic 1 h PG (≥11.6 mmol/L: OR 3.05; 95% CI 1.29–7.23). After adjusting for blood pressure and age, the association of elevated 1 h PG with albuminuria remained significant. Prediabetic or diabetic FPG, 2 h PG, or HbA1c did not have a statistically significant association with albuminuria. These findings suggest that 1 h PG seems to be the best glycemic parameter and is useful in recognizing persons with an elevated risk of early kidney disease due to hyperglycemia.

The clustering of Cardiovascular, Renal, Adipo-Metabolic Eye and Liver disease with type 2 diabetes

Type 2 diabetes is associated with an increased risk of cardiovascular disease, heart failure, chronic kidney disease, fatty liver disease, eye and foot disease. But equally, these conditions are associated with an increased risk of type 2 diabetes. Rather than being simply considered complications of diabetes, as exists within a 'pure' type 1 diabetes paradigm, both type 2 diabetes and its comorbidities are primarily caused by a failure to efficiently sequester excess energy leading to the accumulation of sick fat (adiposopathy). Type 2 diabetes is a symptom of a chronic disease complex, just as cardiovascular, renal, eye, foot and/or liver disease, are. In addition, each of these conditions feed forward so that dysfunction in one system accelerates dysfunction in another, partly through their shared pathogenesis and partly due dysfunction that follows in their wake. This review will explore the sticky, brittle conglomeration of CArdiac, Renal, Adipo-Metabolic, Eye and Liver disease (hereafter collectively known as CARAMEL disease) that is coincident in most patients with type 2 diabetes and contextualise the recent changes in diabetes guidelines that now specifically focus on identifying and aggressively managing these high-risk individuals with it.

Incidence and predictors of chronic kidney disease in type-II diabetes mellitus patients attending at the Amhara region referral hospitals, Ethiopia: A follow-up study

BACKGROUND

Chronic kidney disease (CKD) is the severest form of kidney disease characterized by poor filtration. The magnitude of chronic kidney disease is trending upward in the last few years linked with the rapidly escalating cases of non-communicable chronic diseases, particularly diabetes mellitus. However, little is known about when this problem may occur, the incidence as well as predictors of chronic kidney disease among type-II diabetes mellitus patients. Thus, this study was conducted to determine the incidence, time to the occurrence, and predictors of chronic kidney disease in type-II diabetic patients attending the Amhara region referral hospitals, Ethiopia.

METHODS

A retrospective follow-up study was conducted involving 415 participants with type-II diabetes mellitus that enrolled in the chronic follow-up from 2012 to 2017. Multivariable shared Frailty Weibull (Gamma) survival model was employed considering the hospitals as a clustering variable. Model fitness was checked by both the Akaike information criteria (AIC) and log-likelihood. Factors having a p-value of ≤0.2 in the bi-variable analysis were considered to enter the multivariable model. Variables that had a p-value of <0.05 with its corresponding 95% confidence level were deemed to be significant predictors of chronic kidney disease.

RESULTS

The overall cumulative incidence of chronic kidney disease was 10.8% [95%; CI: 7.7-14.0%] with a median occurrence time of 5 years. The annual incidence rate was 193/10,000 [95%; CI: 144.28-258.78]. Having cardiovascular disease/s [AHR = 3.82; 95%CI: 1.4470-10.1023] and hypercholesterolemia [AHR = 3.31; 95% CI: 1.3323-8.2703] were predictors of chronic kidney disease.

CONCLUSION

One out of every ten diabetic patients experienced chronic kidney disease. The median time to develop chronic kidney disease was five years. Hypercholesterolemia and cardiovascular diseases have escalated the hazard of developing CKD. Thus, health promotion and education of diabetic patients to optimize cholesterol levels and prevent cardiovascular disease is recommended to limit the occurrence of this life-threatening disease.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Trajectories of kidney function in diabetes: a clinicopathological update

Diabetic nephropathy has been traditionally diagnosed based on persistently high albuminuria and a subsequent decline in glomerular filtration rate (GFR), which is widely recognized as the classical phenotype of diabetic kidney disease (DKD). Several studies have emphasized that trajectories of kidney function in patients with diabetes (specifically, changes in GFR and albuminuria over time) can differ from this classical DKD phenotype. Three alternative DKD phenotypes have been reported to date and are characterized by albuminuria regression, a rapid decline in GFR, or non-proteinuric or non-albuminuric DKD. Although kidney biopsies are not typically required for the diagnosis of DKD, a few studies of biopsy samples from patients with DKD have demonstrated that changes in kidney function associate with specific histopathological findings in diabetes. In addition, various clinical and biochemical parameters are related to trajectories of GFR and albuminuria. Collectively, pathological and clinical characteristics can be used to predict trajectories of GFR and albuminuria in diabetes. Furthermore, cohort studies have suggested that the risks of kidney and cardiovascular outcomes might vary among different phenotypes of DKD. A broader understanding of the clinical course of DKD is therefore crucial to improve risk stratification and enable early interventions that prevent adverse outcomes.

Performance of prediction models for nephropathy in people with type 2 diabetes: systematic review and external validation study

OBJECTIVES

To identify and assess the quality and accuracy of prognostic models for nephropathy and to validate these models in external cohorts of people with type 2 diabetes.

DESIGN

Systematic review and external validation.

DATA SOURCES

PubMed and Embase.

ELIGIBILITY CRITERIA

Studies describing the development of a model to predict the risk of nephropathy, applicable to people with type 2 diabetes.

METHODS

Screening, data extraction, and risk of bias assessment were done in duplicate. Eligible models were externally validated in the Hoorn Diabetes Care System (DCS) cohort (n=11 450) for the same outcomes for which they were developed. Risks of nephropathy were calculated and compared with observed risk over 2, 5, and 10 years of follow-up. Model performance was assessed based on intercept adjusted calibration and discrimination (Harrell's C statistic).

RESULTS

41 studies included in the systematic review reported 64 models, 46 of which were developed in a population with diabetes and 18 in the general population including diabetes as a predictor. The predicted outcomes included albuminuria, diabetic kidney disease, chronic kidney disease (general population), and end stage renal disease. The reported apparent discrimination of the 46 models varied considerably across the different predicted outcomes, from 0.60 (95% confidence interval 0.56 to 0.64) to 0.99 (not available) for the models developed in a diabetes population and from 0.59 (not available) to 0.96 (0.95 to 0.97) for the models developed in the general population. Calibration was reported in 31 of the 41 studies, and the models were generally well calibrated. 21 of the 64 retrieved models were externally validated in the Hoorn DCS cohort for predicting risk of albuminuria, diabetic kidney disease, and chronic kidney disease, with considerable variation in performance across prediction horizons and models. For all three outcomes, however, at least two models had C statistics >0.8, indicating excellent discrimination. In a secondary external validation in GoDARTS (Genetics of Diabetes Audit and Research in Tayside Scotland), models developed for diabetic kidney disease outperformed those for chronic kidney disease. Models were generally well calibrated across all three prediction horizons.

CONCLUSIONS

This study identified multiple prediction models to predict albuminuria, diabetic kidney disease, chronic kidney disease, and end stage renal disease. In the external validation, discrimination and calibration for albuminuria, diabetic kidney disease, and chronic kidney disease varied considerably across prediction horizons and models. For each outcome, however, specific models showed good discrimination and calibration across the three prediction horizons, with clinically accessible predictors, making them applicable in a clinical setting.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020192831.

Incidence of Diabetic Nephropathy and Its Predictors among Type 2 Diabetes Mellitus Patients at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia

Background

Although the rate of diabetic nephropathy which is the leading cause of end-stage renal disease (ESRD) continues to rise, there is limited information about the problem. This study aimed to assess the incidence and predictors of diabetic nephropathy among type 2 DM patients.

Methods

Institution-based retrospective follow-up study was conducted at UGCSH with 462 newly diagnosed type 2 DM patients from January 2001 to February 2016, and the data were collected by reviewing their records. The Schoenfeld residuals test was used to check proportional hazard assumption. The best model was selected by using Akaike information criteria (AIC). Hazard ratios (HR) with its respective 95% confidence interval were reported to show significance and strength of association.

Results

The incidence rate of diabetic nephropathy was 14 (95% CI 10.8–17.7) cases per 10,000 patient-month observation. In addition, 63 (13.6%) DM patients developed diabetic nephropathy. The median time to develop diabetic nephropathy was 94.9 months with interquartile range (IOR) of (64.1–127.4) months. Type 2 DM patients who had coronary heart disease (AHR = 2.69, 95% CI 1.42–5.13) and anemia (AHR = 1.94, 95% CI 0.97–3.87) were at higher hazard for developing diabetic nephropathy. Besides this, having a long duration (>10 years) (AHR = 0.24, 95% CI 0.11–0.56) and being female (AHR = 0.44, 95% CI 0.26–0.73) was found to be protective against diabetic nephropathy.

Conclusion

The incidence of diabetic nephropathy among type 2 diabetes patients remains a significant public health problem. Duration of diabetes >10 years and female sex reduced the risk of diabetic nephropathy. Coronary heart disease and anemia increased the risk of diabetic nephropathy among type 2 DM patients. In light of these findings, early screening for diabetes complication is needed, and health professionals should give targeted intervention for type 2 DM patients with coronary heart disease comorbidity and anemia.

High Incidence of Chronic Kidney Disease among Iranian Diabetic Adults: Using CKD-EPI and MDRD Equations for Estimated Glomerular Filtration Rate

BACKGROUND

To investigate the population based incidence rate of chronic kidney disease (CKD) and its potential risk factors among Iranian diabetic adults during over 14 years of follow-up.

METHODS

Two different equations (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] and Modification of Diet in Renal Disease [MDRD]) were applied for the calculating the estimated glomerular filtration rate (eGFR). Among a total of 1,374 diabetic Tehranian adults, 797 and 680 individuals were eligible for CKD-EPI and MDRD analyses, respectively. CKD was defined as eGFR lower than 60 mL/min/1.73 m2. Multivariable Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CI) for all potential risk factors.

RESULTS

The incidence rates (95% CI) of CKD per 1,000 person-years were 43.84 (39.49 to 48.66) and 55.80 (50.29 to 61.91) based on CKD-EPI and MDRD equations, respectively. Being older, a history of cardiovascular disease, and having lower levels of eGFR were significant risk factors in both equations. Moreover, in CKD-EPI, using glucose-lowering medications and hypertension, and in MDRD, female sex and fasting plasma glucose ≥10 mmol/L were also independent risk factors. Regarding the discrimination index, CKD-EPI equation showed a higher range of C-index for the predicted probability of incident CKD in the full-adjusted model, compared to MDRD equation (0.75 [0.72 to 0.77] vs. 0.69 [0.66 to 0.72]).

CONCLUSION

We found an incidence rate of more than 4%/year for CKD development among our Iranian diabetic population. Compared to MDRD, it can be suggested that CKD-EPI equation can be a better choice to use for prediction models of incident CKD among the Iranian diabetic populations.

Albuminuria Testing in Hypertension and Diabetes: An Individual-Participant Data Meta-Analysis in a Global Consortium

Albuminuria is an under-recognized component of chronic kidney disease definition, staging, and prognosis. Guidelines, particularly for hypertension, conflict on recommendations for urine albumin-to-creatinine ratio (ACR) measurement. Separately among 1 344 594 adults with diabetes and 2 334 461 nondiabetic adults with hypertension from the chronic kidney disease Prognosis Consortium, we assessed ACR testing, estimated the prevalence and incidence of ACR ≥30 mg/g and developed risk models for ACR ≥30 mg/g. The ACR screening rate (cohort range) was 35.1% (12.3%-74.5%) in diabetes and 4.1% (1.3%-20.7%) in hypertension. Screening was largely unrelated to the predicted risk of prevalent albuminuria. The median prevalence of ACR ≥30 mg/g across cohorts was 32.1% in diabetes and 21.8% in hypertension. Higher systolic blood pressure was associated with a higher prevalence of albuminuria (odds ratio [95% CI] per 20 mm Hg in diabetes, 1.50 [1.42-1.60]; in hypertension, 1.36 [1.28-1.45]). The ratio of undetected (due to lack of screening) to detected ACR ≥30 mg/g was estimated at 1.8 in diabetes and 19.5 in hypertension. Among those with ACR <30 mg/g, the median 5-year incidence of ACR ≥30 mg/g across cohorts was 23.9% in diabetes and 21.7% in hypertension. Incident albuminuria was associated with initiation of renin-angiotensin-aldosterone system inhibitors (incidence-rate ratio [95% CI], diabetes 3.09 [2.71-3.53]; hypertension 2.87 [2.29-3.59]). In conclusion, despite similar risk of albuminuria to those with diabetes, ACR screening in patients with hypertension was low. Our findings suggest that regular albuminuria screening should be emphasized to enable early detection of chronic kidney disease and initiation of treatment with cardiovascular and renal benefits.

Association between cotinine-verified smoking status and moderately increased albuminuria in the middle-aged and older population in Korea: A nationwide population-based study

Objectives

Although several self-reported questionnaire-based studies have found an association between smoking and moderately increased albuminuria, this result remains controversial. We investigated whether moderately increased albuminuria was associated with smoking status, verified by urinary cotinine (an objective biomarker of tobacco exposure), using population-based, nationally representative data.

Methods

This study included 2059 participants aged ≥ 50 years from the 2014 Korean National Health and Nutrition Examination Survey. Individuals with a urinary cotinine level ≥ 50 ng/mL were identified as cotinine-verified smokers. Moderately increased albuminuria was defined as a urine albumin-to-creatinine ratio ranging between ≥ 30 mg/g and < 300 mg/g. Multivariable logistic regression was used to evaluate the association between cotinine-verified smoking status and moderately increased albuminuria.

Results

Among the study participants, 16.9% were cotinine-verified smokers, 84.8% of whom were men. After adjustment for multiple covariates, cotinine-verified smokers showed a significant positive association with moderately increased albuminuria (adjusted odds ratio: 4.37, 95% confidence interval: 1.63–11.71) compared with cotinine-verified non-smokers. The association between urinary cotinine and moderately increased albuminuria did not differ with age, sex, obesity, or comorbidities (P-value for interaction > 0.05 in all cases).

Conclusion

This large-scale observational study showed that cotinine-verified smoking is associated with moderately increased albuminuria in the Korean middle-aged and older general population, suggesting that smoking must be strictly controlled to reduce the risk of moderately increased albuminuria.

Diabetic kidney disease in patients newly diagnosed with type-2 diabetes mellitus: Incidence and associations

The global prevalence of type 2 diabetes mellitus (DM) in adults is increasing all over the world. Diabetic kidney disease (DKD) is one of the most common complications of DM. The aim of the present work is to study chronic kidney disease (CKD) in patients newly diagnosed with type 2 DM as regards incidence and associations. This is a comparative cross-sectional study. The study included 153 patients with newly diagnosed type 2 DM over the past six months. DKD was diagnosed if urinary albumin to creatinine ratio >30 mg/g in two out of three-morning urine samples collected within three to six months and/or estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² using 2009 CKD-Epidemiology Collaboration creatinine equation. DKD was present in 45.75% of patients. In our study, 54.9% of patients had microalbuminuria, 39.2% had macroalbuminuria, and 5.9% had severely increased albuminuria. As regards eGFR, 5.2% of patients had eGFR <60 mL/min/1.73 m². Regression analysis showed that increased levels of cholesterol, triglyceride, and glycated hemoglobin were associated with an increased likelihood of developing nephropathy while nonsmoking and elevated high-density lipoprotein cholesterol levels were associated with a reduction in that likelihood. DKD was present in a substantial proportion of our patients at diagnosis. Routine screening for DKD is recommended in all patients early at the onset itself of diagnosis with type 2 DM.

Acarbose Reduces Low-Grade Albuminuria Compared to Metformin in Chinese Patients with Newly Diagnosed Type 2 Diabetes

PURPOSE

To assess the effect of acarbose in lowering low-grade albuminuria compared to metformin in newly diagnosed Chinese type 2 diabetes (T2DM) patients.

PATIENTS AND METHODS

The Metformin and AcaRbose Clinical Trial was a randomized, open-label trial in newly diagnosed T2DM patients. Participants received 48 weeks of monotherapy with acarbose (100 mg three times a day) or metformin (1500 mg once a day). As the hypoglycemic effect of acarbose and metformin has been evaluated in previous reports. This analysis studied the effect of the two antidiabetic drugs on reducing urinary albumin. The percent change in the urinary albumin/creatinine ratio (uACR) from baseline to week 48 was analyzed, and ANCOVA was employed to establish whether the effect in decreasing uACR was mediated by metabolic improvement.

RESULTS

Acarbose reduced the adjusted mean percent uACR by -31.5% (95% confidence interval [CI] -48.4 to -7.5) compared with metformin. When adjusting for changes in glycated hemoglobin, body weight, systolic blood pressure and triglycerides or changes in area under the curve of glucagon-like peptide 1 (AUCGLP-1) in the standard meal test, the uACR-lowering effect was not attenuated. If stratified by eGFR, blood glucose level, sex or uACR level, the effect of acarbose versus metformin was consistent across subgroups. The proportion of patients with a reduction in uACR of at least 70% was 48.6% in the acarbose group and 34.1% in the metformin group.

CONCLUSION

Acarbose lowered the uACR compared to metformin in newly diagnosed T2DM patients independent of improvements in hyperglycemia, blood pressure, body weight and triglycerides.

Assessment of renal impairment using estimated glomerular filtration rate among type 2 diabetes mellitus patients in North-East Ethiopia: a cross-sectional study

BACKGROUND

Chronic kidney disease (CKD) is the known cause of morbidity and mortality among diabetes mellitus (DM) patients. Targeted screening of renal impairment based on estimated glomerular filtration rate (eGFR) among DM patients has potential benefits in early identification and treatment of CKD. Hence, this study was aimed to estimate the magnitude of renal impairment using eGFR among type 2 DM patients.

METHODS

An institution-based cross-sectional study was conducted from February-1 to April 30/2020 among 422 type 2 DM patients in Northeast Ethiopia. Data were collected by the semi-structured questioner and serum creatinine measurement. The collected data were edited into Epi-data manager version 4.4.1.0, and the analysis was performed by SPSS-25. The Simplified Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology (CKD-EPI), and Cockcroft-Gault (C-G) equations were used to calculate eGFR.

RESULTS

Of all study participants, 82(19.4%), 92(21.8%), and 103(24.4%) had eGFR < 60 ml/min/1.73 m², according to the MDRD, CKD-EPI, and C-G equations, respectively. Female sex, (MDRD:AOR = 4.44, 95%CI:1.97-9.97, CKD-EPI:AOR = 3.17, 95%CI:1.27-6.17, and C-G:AOR = 2.65, 95%CI:1.35-5.21), duration ≥ 10 years (MDRD:AOR = 3.38, 95%CI:1.45-7.92, CKD-EPI:AOR = 3.09, 95%CI:1.07-7.77, and C-G:AOR = 2.92, 95%CI:1.29-6.61), age ˃60 years (MDRD:AOR = 2.29, 95%CI:1.09-4.77, CKD-EPI:AOR = 4.12, 95%CI:1.68-6.78, and C-G: AOR = 3.42, 95%CI:1.77-6.60), hypertension (MDRD:AOR = 3.12, 95%CI:1.51-6.45, CKD-EPI: AOR = 4.21,95%CI:2.07-7.98, and C-G:AOR = 3.99, 95%CI:2.08-7.65), poor glycemic control (MDRD:AOR = 2.82, 95%CI:1.13-7.05, and C-G:AOR = 2.34, 95%CI:1.09-5.04), and body mass index (MDRD:AOR = 1.11, 95%CI:1.01-1.22, and CKD-EPI:AOR = 2.43, 95%CI:1.27-5.76) were significantly associated with renal impairment.

CONCLUSION

Renal impairment was prevalent among type 2 DM patients. Older age, female sex, duration, hypertension, poor glycemic control, and BMI were significantly associated with renal impairment.

Incidence and Associations of Chronic Kidney Disease in Community Participants With Diabetes: A 5-Year Prospective Analysis of the EXTEND45 Study

OBJECTIVE

To determine the incidence of and factors associated with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² in people with diabetes.

RESEARCH DESIGN AND METHODS

We identified people with diabetes in the EXamining ouTcomEs in chroNic Disease in the 45 and Up Study (EXTEND45), a population-based cohort study (2006-2014) that linked the Sax Institute's 45 and Up Study cohort to community laboratory and administrative data in New South Wales, Australia. The study outcome was the first eGFR measurement <60 mL/min/1.73 m² recorded during the follow-up period. Participants with eGFR < 60 mL/min/1.73 m² at baseline were excluded. We used Poisson regression to estimate the incidence of eGFR <60 mL/min/1.73 m² and multivariable Cox regression to examine factors associated with the study outcome.

RESULTS

Of 9,313 participants with diabetes, 2,106 (22.6%) developed incident eGFR <60 mL/min/1.73 m² over a median follow-up time of 5.7 years (interquartile range, 3.0-5.9 years). The eGFR <60 mL/min/1.73 m² incidence rate per 100 person-years was 6.0 (95% CI 5.7-6.3) overall, 1.5 (1.3-1.9) in participants aged 45-54 years, 3.7 (3.4-4.0) for 55-64 year olds, 7.6 (7.1-8.1) for 65-74 year olds, 15.0 (13.0-16.0) for 75-84 year olds, and 26.0 (22.0-32.0) for those aged 85 years and over. In a fully adjusted multivariable model incidence was independently associated with age (hazard ratio 1.23 per 5-year increase; 95% CI 1.19-1.26), geography (outer regional and remote versus major city: 1.36; 1.17-1.58), obesity (obese class III versus normal: 1.44; 1.16-1.80), and the presence of hypertension (1.52; 1.33-1.73), coronary heart disease (1.13; 1.02-1.24), cancer (1.30; 1.14-1.50), and depression/anxiety (1.14; 1.01-1.27).

CONCLUSIONS

In participants with diabetes, the incidence of an eGFR <60 mL/min/1.73 m² was high. Older age, remoteness of residence, and the presence of various comorbid conditions were associated with higher incidence.

Establishment and Validation of a Risk Prediction Model for Early Diabetic Kidney Disease Based on a Systematic Review and Meta-Analysis of 20 Cohorts

BACKGROUND

Identifying patients at high risk of diabetic kidney disease (DKD) helps improve clinical outcome.

PURPOSE

To establish a model for predicting DKD.

DATA SOURCES

The derivation cohort was from a meta-analysis. The validation cohort was from a Chinese cohort.

STUDY SELECTION

Cohort studies that reported risk factors of DKD with their corresponding risk ratios (RRs) in patients with type 2 diabetes were selected. All patients had estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m² and urinary albumin-to-creatinine ratio (UACR) <30 mg/g at baseline.

DATA EXTRACTION

Risk factors and their corresponding RRs were extracted. Only risk factors with statistical significance were included in our DKD risk prediction model.

DATA SYNTHESIS

Twenty cohorts including 41,271 patients with type 2 diabetes were included in our meta-analysis. Age, BMI, smoking, diabetic retinopathy, hemoglobin A_1c, systolic blood pressure, HDL cholesterol, triglycerides, UACR, and eGFR were statistically significant. All these risk factors were included in the model except eGFR because of the significant heterogeneity among studies. All risk factors were scored according to their weightings, and the highest score was 37.0. The model was validated in an external cohort with a median follow-up of 2.9 years. A cutoff value of 16 was selected with a sensitivity of 0.847 and a specificity of 0.677.

LIMITATIONS

There was huge heterogeneity among studies involving eGFR. More evidence is needed to power it as a risk factor of DKD.

CONCLUSIONS

The DKD risk prediction model consisting of nine risk factors established in this study is a simple tool for detecting patients at high risk of DKD.

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.

Presence of Carotid Plaque Is Associated with Rapid Renal Function Decline in Patients with Type 2 Diabetes Mellitus and Normal Renal Function

BACKGROUND

Recent evidences indicate that early rapid renal function decline is closely associated with the development and progression of diabetic kidney disease. We have investigated the association between carotid atherosclerosis and rapid renal function decline in patients with type 2 diabetes mellitus and preserved renal function.

METHODS

In a prospective, multicenter cohort, a total of 967 patients with type 2 diabetes mellitus and preserved renal function were followed for 6 years with serial estimated glomerular filtration rate (eGFR) measurements. Common carotid intima-media thickness (CIMT) and presence of carotid plaque were assessed at baseline. Rapid renal function decline was defined as an eGFR decline >3.3% per year.

RESULTS

Over a median follow-up of 6 years, 158 participants (16.3%) developed rapid renal function decline. While there was no difference in CIMT, the presence of carotid plaque in rapid decliners was significantly higher than in non-decliners (23.2% vs. 12.2%, P<0.001). In multivariable logistic regression analysis, presence of carotid plaque was an independent predictor of rapid renal function decline (odds ratio, 2.33; 95% confidence interval, 1.48 to 3.68; P<0.0001) after adjustment for established risk factors. The model including the carotid plaque had better performance for discrimination of rapid renal function decline than the model without carotid plaque (area under the receiver operating characteristic curve 0.772 vs. 0.744, P=0.016).

CONCLUSION

Close monitoring of renal function and early intensive management may be beneficial in patients with type 2 diabetes mellitus and carotid plaques.

Risk factors and urinary biomarkers of non-albuminuric and albuminuric chronic kidney disease in patients with type 2 diabetes

BACKGROUND

A number of recent studies indicate a transformation in the natural course of chronic kidney disease (CKD) in type 2 diabetes (T2D) patients: an increasing prevalence of declined renal function without proceeding to the accompanying elevation of albuminuria. It has been suggested that albuminuric and non-albuminuric CKD patterns could be different in their phenotypes and pathogenic mechanisms.

AIM

To identify the risk factors and biomarkers of albuminuric and non-albuminuric patterns of CKD in patients with T2D.

METHODS

Three hundred sixty patients with T2D duration ≥ 10 years were included in this observational cross-sectional study. The associations of a panel of demographic and clinical characteristics, complications, comorbidities, and metabolic and hematology parameters with albuminuric and non-albuminuric CKD patterns were analyzed. The urinary excretion of nephrin and podocin, two podocyte-specific markers, and WAP-four-disulfide core domain protein 2 (WFDC-2), a marker of tubulointerstitial fibrosis, was determined by ELISA in comparison with healthy controls.

RESULTS

Non-albuminuric CKD was associated with age ≥ 65 years (P = 0.0001), female sex (P = 0.04), diabetes duration ≥ 15 years (P = 0.0009), and the use of diuretics (P = 0.0005). Male sex (P = 0.01), smoking (P = 0.01), waist-to-hip ratio >1.0 (P = 0.01) and hemoglobin A1c (HbA1c) > 8.0% (P = 0.005) were risk factors for elevated albuminuria not accompanied by a decrease in estimated glomerular filtration rate (eGFR). Duration of diabetes ≥ 15 years and the use of calcium channel blockers were risk factors for albuminuria with decreased eGFR (both P = 0.01). In multivariate logistic regression analysis, age, HbA1c, female sex and diuretics were significant predictors for reduced eGFR, while waist-to-hip ratio, HbA1c and male sex were associated with elevated urinary albumin-to-creatinine ratio (UACR). Excretion of nephrin and podocin was increased in patients with albuminuria, regardless of decline in renal function (P < 0.001), correlating positively with UACR. The urinary excretion of WFDC-2 was markedly higher in men than in women (P < 0.000001). Men with T2D demonstrated increased WFDC-2 levels independently of the CKD pattern (all P < 0.05). In T2D women, WFDC-2 excretion was increased in those with reduced renal function (P ≤ 0.01), correlating negatively with eGFR.

CONCLUSION

The data provide further evidence that albuminuric and non-albuminuric CKD phenotypes correspond to different pathways of diabetic kidney disease progression.

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.

Cardiorenal prognosis by residual proteinuria level in diabetic chronic kidney disease: pooled analysis of four cohort studies

Background

No study has assessed whether the prognosis of coexisting diabetes mellitus and chronic kidney disease (DM-CKD) is dictated by DM per se or by the extent of proteinuria.

Methods

In this pooled analysis of four prospective studies in CKD patients treated with drugs inhibiting the renin-angiotensin system, we compared the risk of all-cause mortality, fatal and non-fatal cardiovascular (CV) events and end-stage renal disease (ESRD) between patients with (n = 693) and without diabetes (n = 1481) stratified by proteinuria level (<0.15, 0.15-0.49, 0.5-1 and  >1 g/day).

Results

The group with DM-CKD was older (69 ± 11 versus 65 ± 15 years), had a higher body mass index (29.6 ± 5.4 versus 27.5 ± 4.8 kg/m2) and systolic blood pressure (143 ± 19 versus 136 ± 18 mmHg), prevalent CV disease (48% versus 29%) and lower estimated glomerular filtration rate (34.5 ± 17.9 versus 36.6 ± 19.0 mL/min/1.73 m2). During 4.07 years of follow-up, there were 466 patients with ESRD, 334 deaths and 401 CV events occurred. In the subgroup with urine protein <0.15 g/day (N = 662), the risks of ESRD, CV events and mortality were similar in diabetic and non-diabetic patients. Conversely, in DM-CKD patients, the mortality risk was higher in proteinuric patients {hazard ratio 1.92 [95% confidence interval (CI) 1.25-2.95); 1.99 (1.26-3.15) and 1.98 (1.28-3.06) for proteinuria 0.15-0.49, 0.5-1 and >1 g/day, respectively}, whereas in non-diabetics the mortality risk increased only for proteinuria 0.5-1 g/day [HR 1.60 (95% CI 1.07-2.40)] and >1 g/day [HR 1.69 (95% CI1.20-2.55)]. In both groups, CV risk had a trend similar to that of mortality. ESRD risk increased progressively across strata >0.5 g/day independent of diabetic status.

Conclusions

We provide evidence that patients with non-proteinuric DM-CKD are not exposed to higher cardiorenal risk. In contrast, in the presence of moderate proteinuria and diabetes per se is associated with a higher risk of mortality and CV events, whereas the entity of abnormal proteinuria modulates ESRD risk independent of diabetes.

Association of OSAHS Hypoxia Indicators with Early Renal Injury and Serum Fibroblast Growth Factor 21 in Obese Type 2 Diabetic Patients

OBJECTIVE

This study aimed to explore the association of obstructive sleep apnea-hypopnea syndrome (OSAHS) hypoxia indicators with early renal injury and serum fibroblast growth factor 21 (FGF21) in obese type 2 diabetic patients.

METHODS

A total of 109 obese patients with type 2 diabetes mellitus (T2DM) were recruited, including 70 males and 39 females, with an average age of 52.77 ± 13.57 years and average BMI of 29.08 ± 4.36 kg/m2. Overnight sleep monitoring was performed with a portable monitor to record respiratory parameters [apnea-hypopnea index (AHI), oxygen desaturation index (ODI), lowest oxygen saturation (LSaO2), mean oxygen saturation (MSaO2/MPO2) and cumulative time of oxygen saturation < 90% (CT < 90%)]. Ultrasonography was done to detect the quantitative liver fat content (LFC). The urine microalbumin and creatinine ratio (ACR) were determined by immunoturbidimetry. FGF21 was measured at baseline by enzyme-linked immunosorbent assay. Patients were divided into the proteinuria group (n = 42) and non-proteinuria group (n = 67). Correlation analysis and multivariate linear regression analysis were used to analyze the related data. In addition, patients were divided into the T2DM without OSAHS group (n = 16) and T2DM with OSAHS group (n = 93) according to the AHI value. The correlation analysis was used to assess the relationship between FGF21 and clinical variables.

RESULTS

(1) ACR positively correlated with waist circumference (WC), AHI, ODI, CT < 90% and LFC, but negatively with MSaO2 and LSaO2. (2) AHI, ODI, CT < 90% and LFC were independent risk factors for ACR, LSaO2 and MSaO2 was a protective factor. (3) Serum FGF21 decreased in the OSAHS group compared with the non-OSAHS group. After adjustment for age, WC and TG, FGF21 correlated negatively with AHI, but positively with MSaO2.

CONCLUSIONS

AHI, ODI, CT < 90% and LFC are independent risk factors for ACR. FGF21 is associated with hypoxia indicators, and improving OSAHS status and reducing liver fat content may be helpful for the prevention and treatment of early diabetic nephropathy (DN).

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-IOR-15006225.

Higher pulse pressure predicts initiation of dialysis in Japanese patients with diabetes

AIMS

To determine incidence and predictors of starting dialysis in patients with diabetes emphasizing blood pressure variables.

METHODS

A nationwide database with claim data on 18 935 people (15 789 men and 3146 women) with diabetes mellitus aged 19 to 72 years in Japan was used to elucidate predictors for starting dialysis. Initiation of dialysis was determined from claims using ICD-10 codes and medical procedures. Using multivariate Cox modelling, interactions between glycaemic and blood pressure values were determined.

RESULTS

During a median follow-up of 5.3 years, incidence of dialysis was 0.81 per 1000 person-years. Multivariate analysis of a model involving systolic and diastolic blood pressure (SBP and DBP) simultaneously as covariates showed that hazard ratios (HRs) for starting dialysis for each 1-SD elevation in SBP and DBP were 2.05 (95% confidence interval 1.58-2.64) and 0.66 (0.50-0.88), respectively, implying that pulse pressure (PP) was a promising predictor. For confirmation, a model involving SBP and PP simultaneously as covariates demonstrated that HRs for each 1-SD elevation in SBP and PP were 1.09 (0.81-1.48) and 1.54 (1.14-2.08), respectively, with PP the more potent predictor. Compared with HbA_1c <8% and PP <60 mmHg, the HR for those with HbA_1c ≥8% and PP ≥60 mmHg was 6.32 (3.42-11.7).

CONCLUSIONS

In our historical cohort analysis, SBP and PP were independent predictors for starting dialysis. PP was the more potent, suggesting the contribution of increased arterial stiffness to the incidence of dialysis. Future studies are needed to conclude the independent influence of PP and HbA_1c on dialysis considering other risk factors.

Albuminuric and non-albuminuric patterns of chronic kidney disease in type 2 diabetes

A growing body of evidence supports a shift in the natural history of chronic kidney disease (CKD) in subjects with diabetes. Specifically, normoalbuminuric chronic kidney disease (NA-CKD), which is characterized by a decline in the glomerular filtration rate in the absence of a preceding or accompanying elevation of albuminuria, has become a widely prevalent variant of renal impairment in diabetes. Diabetic women and nonsmoking individuals with better glycemic control have a better chance of preserving normoalbuminuria, even in the case of declining renal function. The wide use of renin-angiotensin system blockers, advances in antihyperglycemic, antihypertensive, and hypolipidemic therapy, and smoking cessation are suspected to be responsible for an increasing proportion of NA-CKD among diabetic subjects with renal impairment. Significant differences in the sets of risk factors, renal morphology, comorbidity, and outcomes were found between the albuminuric and normoalbuminuric CKD patterns. NA-CKD, even if a more favorable option in terms of the risk of end-stage renal disease, is clearly associated with cardiovascular disease and its risk factors. The presence of NA-CKD in patients with diabetes increases the risk of myocardial infarction, stroke, and cardiovascular death. The study of the molecular pathways, clinical course, and outcomes of NA-CKD in diabetic subjects and the search for more specific diagnostic and treatment options are challenges for future research.

Identification of Urinary Metabolite Biomarkers of Type 2 Diabetes Nephropathy Using an Untargeted Metabolomic Approach

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus (DM). To discover early stage biomarkers of DN, untargeted liquid chromatography-mass spectrometry-based metabolomic analysis was performed in urine samples from healthy subjects and patients with micro- or macroalbuminuria due to nondiabetic disease (macro), type 2 DM without microalbuminuria (T2DM), and type 2 DM with microalbuminuria (T2DM+micro). Levels of four metabolites were significantly different among groups, and they were quantified in a larger group of 267 urine samples. Two metabolites were also discovered and validated in targeted metabolic study of amino acids. For diagnosis of nephropathy, N1-methylguanosine had the highest area-under-the-curve (AUC) value of 0.75 when compared to those of valine (0.68), xanthosine (0.67), and 7-methyluric acid (0.69). After combining fasting blood glucose and diastolic blood pressure (DBP) with N1-methylguanosine, the AUC increased to 0.987. To distinguish between T2DM and T2DM+micro conditions, xanthosine and N1-methylguanosine have AUC value of 0.612 and 0.624, respectively. After adjustment of HbA1c and DBP, AUC values of xanthosine and N1-methylguanosine increased to 0.716 and 0.723, respectively, and could be used to predict the development of nephropathy in T2DM patients.

Normoalbuminuric chronic kidney disease in diabetes

Urinary albumin excretion (UAE) is widely used in clinical practice as indicator of diabetic kidney disease. According to the classical concept of the natural course of diabetic nephropathy, an increase in UAE usually precedes a decline in renal function. Meanwhile, a growing body of evidences indicates a high prevalence of normoalbuminuric chronic kidney disease (NA-CKD) in diabetic subjects, especially among patients with type 2 diabetes. An increase in NA-CKD prevalence can be results of improved glucose, blood pressure, and lipid control, widespread use of renin-angiotensin system blockers, and smoking cessation. It was shown that NA-CKD is more prevalent among women and is associated with arterial hypertension and coronary artery disease. The renal structure in subjects with NA-CKD is more heterogeneous when compared to patients with increased albuminuria, wherein interstitial changes and arteriolosclerosis could be the principal morphological findings, while signs of glomerulopathy may be absent. The prognostic value of NA-CKD needs to be clarified. It was shown that NA-CKD increases the risk of myocardial infarction, stroke and cardiovascular death in patients with diabetes. The search for alternative diagnostic markers for detecting of diabetic kidney disease in the absence of albuminuria, is of practical importance. The evaluations of the markers of tubular damage and interstitial fibrosis, as well as proteomic approaches, are considered as perspective diagnostic and prognostic options in NA-CKD. The study of pathogenesis, pathology, clinical course of NA-CKD in diabetic patients, as well as the development of more specific diagnostic and treatment options is a challenge for future research.

Incidence and predictors of chronic kidney diseases among type 2 diabetes mellitus patients at St. Paul's Hospital, Addis Ababa, Ethiopia

OBJECTIVE

This study aimed to estimate the incidence of chronic kidney disease and its predictors among newly diagnosed type 2 diabetes patients attending St. Paul's Hospital, Addis Ababa, Ethiopia.

RESULTS

The overall incidence of chronic kidney disease was a major public health issue among type 2 diabetes mellitus patients with 2178 (95% CI 12,801, 21,286) cases per 10,000 patient-months. Moreover, 62(14.25%) patients in the sample experienced chronic kidney disease. Old age [adjusted hazard ratio (AHR) = 1.06, 95%CI 1.03, 1.09], no diabetic retinopathy [AHR = 0.13, 95%CI 0.07-0.24], high density lipoprotein cholesterol ≥ 40 mg/dl [AHR = 0.55, 95%CI 0.31, 0.97] and high body mass index [AHR = 1.17, 95%CI 1.1, 1.25] were common factors for chronic kidney diseases.

Association of proton pump inhibitor use with the risk of the development or progression of albuminuria among Japanese patients with diabetes: A prospective cohort study [Diabetes Distress and Care Registry at Tenri (DDCRT 16)]

AIMS

We aimed to determine the prospective association between proton pump inhibitor (PPI) use and the subsequent risk of the development or progression of albuminuria or eGFR.

METHODS

Longitudinal data of patients with diabetes were obtained from a large Japanese diabetes registry. To assess the independent correlation between PPI use and the development or progression of urine microalbuminuria, the time-varying Cox proportional hazards model was used with adjustment for potential confounders.

RESULTS

The mean patient age, body-mass index (BMI), and hemoglobin A1c (HbA1c) levels were 65.7 y, 24.5 kg/m², and 7.5% (57.9 mmol/mol), respectively. In 1711 patients without albuminuria, we observed 599 cases with development of albuminuria over median follow-up of 4.0 years, and in 1279 patients with microalbuminuria, 290 cases with urinary albuminuria progression over 4.0 years, and 257 eGFR decline cases over 3.8 years. PPI use was not associated with the development of albuminuria (HR = 0.88; 95%CI, 0.77-1.01; p = .058), progression of albuminuria (HR = 1.24; 95%CI, 0.87-1.79; p = .236), nor eGFR decline (HR = 1.05; 95%CI, 0.81-1.34; p = .973) even in a propensity score-adjusted model with time-varyingly updating PPI use information.

CONCLUSIONS

In conclusion, PPI use was not associated with the subsequent risk of development or progression of albuminuria, or eGFR decline in patients with diabetes.

Albuminuria, serum creatinine, and estimated glomerular filtration rate as predictors of cardio-renal outcomes in patients with type 2 diabetes mellitus and kidney disease: a systematic literature review

BACKGROUND

Albuminuria, elevated serum creatinine and low estimated glomerular filtration rate (eGFR) are pivotal indicators of kidney decline. Yet, it is uncertain if these and emerging biomarkers such as uric acid represent independent predictors of kidney disease progression or subsequent outcomes among individuals with type 2 diabetes mellitus (T2DM). This study systematically examined the available literature documenting the role of albuminuria, serum creatinine, eGFR, and uric acid in predicting kidney disease progression and cardio-renal outcomes in persons with T2DM.

METHODS

Embase, MEDLINE, and Cochrane Central Trials Register and Database of Systematic Reviews were searched for relevant studies from January 2000 through May 2016. PubMed was searched from 2013 until May 2016 to retrieve studies not yet indexed in the other databases. Observational cohort or non-randomized longitudinal studies relevant to albuminuria, serum creatinine, eGFR, uric acid and their association with kidney disease progression, non-fatal cardiovascular events, and all-cause mortality as outcomes in persons with T2DM, were eligible for inclusion. Two reviewers screened citations to ensure studies met inclusion criteria.

RESULTS

From 2249 citations screened, 81 studies were retained, of which 39 were omitted during the extraction phase (cross-sectional [n = 16]; no outcome/measure of interest [n = 13]; not T2DM specific [n = 7]; review article [n = 1]; editorial [n = 1]; not in English language [n = 1]). Of the remaining 42 longitudinal study publications, biomarker measurements were diverse, with seven different measures for eGFR and five different measures for albuminuria documented. Kidney disease progression differed substantially across 31 publications, with GFR loss (n = 9 [29.0%]) and doubling of serum creatinine (n = 5 [16.1%]) the most frequently reported outcome measures. Numerous publications presented risk estimates for albuminuria (n = 18), serum creatinine/eGFR (n = 13), or both combined (n = 6), with only one study reporting for uric acid. Most often, these biomarkers were associated with a greater risk of experiencing clinical outcomes.

CONCLUSIONS

Despite the utility of albuminuria, serum creatinine, and eGFR as predictors of kidney disease progression, further efforts to harmonize biomarker measurements are needed given the disparate methodologies observed in this review. Such efforts would help better establish the clinical significance of these and other biomarkers of renal function and cardio-renal outcomes in persons with T2DM.

CE: Improving Outcomes for Patients with Chronic Kidney Disease: Part 1

: The burden of chronic kidney disease (CKD) is rising both in this country and worldwide. An estimated 10% to 15% of U.S. adults are currently living with CKD. Reducing the CKD burden requires a systematic, interdisciplinary approach to care. The greatest opportunities to reduce the impact of CKD arise early, when most patients are being followed in primary care; yet many clinicians are inadequately educated on this disease. Nurses are well positioned to facilitate the implementation of collaborative care. This two-part article aims to provide nurses with the basic information necessary to assess and manage patients with CKD. Part 1 offers an overview of the disease, describes identification and etiology, and discusses ways to slow disease progression. Part 2, which will appear next month, addresses disease complications and treatment of kidney failure.

Clinicopathological features of diabetic and nondiabetic renal diseases in type 2 diabetic patients with nephrotic-range proteinuria

Heavy proteinuria with or without features of nephrotic syndrome is associated with many primary and systemic diseases. For diabetic patients, distinguishing nondiabetic renal disease (NDRD) from diabetic nephropathy (DN) is important in choosing treatment modalities and determining renal prognosis. However, clinical relevance of heavy proteinuria is inconsistent with clinical DN assessments. This study investigated the clinicopathological features and renal outcomes of DN and NDRD in type 2 diabetic patients with nephrotic-range proteinuria.We enrolled 220 cases of type 2 diabetic patients who underwent renal biopsy. They were grouped according to the presence of nephritic-range proteinuria and pathological features. Baseline characteristics, laboratory findings, types of pathological diagnosis, and renal outcomes were analyzed in patients with heavy proteinuria.Upon kidney biopsy, 129 patients (58.6%) showed nephritic-range proteinuria. Patients with heavy proteinuria (an average urine protein-to-creatinine ratio of 10,008 ± 7307 mg/gCr) showed lower serum albumin levels and higher total cholesterol levels, but did not show any difference in age, duration of diabetes, renal function, or the presence of retinopathy compared with those with mild-to-moderate proteinuria (an average urine protein-to-creatinine ratio of 1581 ± 979 mg/gCr). Renal biopsy revealed that the prevalence of NDRD was 37.2% in patients with heavy proteinuria, which was significantly lower than that in patients with mild-to-moderate proteinuria (63.7%). The most common pathological types of NDRD were membranous nephropathy (41.7%), IgA nephropathy (14.6%), and minimal change disease (10.4%). NDRD patients showed lower prevalence of diabetic retinopathy and better kidney function irrespective of proteinuria. Immunosuppressive treatment was administered more frequently in patients with heavy proteinuria (56.3%) compared with patients with mild-to-moderate proteinuria (20%) because of the pathological differences according to the amount of proteinuria. Renal outcomes were significantly worse in patients with DN than in patients with NDRD.DN patients with heavy proteinuria exhibited different prevalence of NDRD and worse prognosis. Renal biopsy in type 2 diabetic patients should be more extensively considered to accurately diagnose NDRD, guide further management, and predict renal outcomes, especially in patients with nephrotic-range proteinuria.

Increased Arterial Stiffness is an Independent Predictor of Renal Function Decline in Patients With Type 2 Diabetes Mellitus Younger Than 60 Years

BACKGROUND

The objective of this study was to evaluate whether aortic pulse wave velocity (Ao-PWV) predicts estimated glomerular filtration rate (eGFR) decline in patients with type 2 diabetes mellitus.

METHODS AND RESULTS

This prospective single-center cohort study investigated 211 type 2 diabetes mellitus patients with eGFR ≥45 mL/min with a baseline mean age of 60.1 years (range, 30-82 years). The mean±SD baseline eGFR was 85±26.1 mL/min. We divided the cohort into 2 groups above (n=117, "older") and below (n=94, "younger") the mean age to evaluate whether Ao-PWV predicted progression of kidney disease differentially in older and younger patients. The primary end point was reaching a final eGFR below the median for the age group and an eGFR fall ≥1 mL/min per year. Median follow-up was 9 years (range, 3-11 years) and ≈50% of patients in both groups reached the primary end point. In older patients, Ao-PWV was similar in those who did and did not reach the primary end point. By contrast, younger patients who reached the primary end point had a higher Ao-PWV at baseline compared with those who did not (10.8 m/s versus 9.5 m/s, respectively; mean difference of 1.36 m/s [95% CI, 0.38-2.33], P=0.007). Ao-PWV was an independent predictor of the primary end point (incident risk ratio, 1.09; 95% CI, 1.02-1.18) after adjustment for traditional risk factors only in younger patients (P=0.02). A 1m/s increase in Ao-PWV was associated with a mean fall in eGFR of 2.1 mL/min per year (95% CI, 0.09-4.1) independent of other risk factors in younger patients (P=0.04).

CONCLUSIONS

Ao-PWV predicts eGFR decline, before the onset of advanced renal dysfunction, and is a potential target for renoprotection in younger patients with type 2 diabetes mellitus.

Postmeal triglyceridemia and variability of HbA1c and postmeal glycemia were predictors of annual decline in estimated glomerular filtration rate in type 2 diabetic patients with different stages of nephropathy

BACKGROUND

This study examined associations of annual glycemic variability and postprandial dysmetabolism with annual decline in estimated glomerular filtration rate (eGFR) in type 2 diabetic patients with different stages of nephropathy.

METHODS

Intrapersonal mean and coefficient of variation (CV) of HbA1c, fasting and postmeal concentrations of plasma glucose (FPG and PMPG, respectively) and serum triglycerides (FTG and PMTG, respectively) during the first 12 months after enrollment were calculated in a cohort of 168 type 2 diabetic patients: 53 with optimal albumin/creatinine ratio (ACR < 10 mg/g), 62 with high normal ACR (10-29 mg/g) and 53 with elevated ACR (≧30 mg/g). Annual changes in eGFR were computed using 52 (median) creatinine measurements obtained over a median follow-up of 6.0 years. Multivariate linear regressions assessed the independent correlates of changes in eGFR.

RESULTS

Kidney function declined faster in patients with high normal and elevated ACR (-1.47 and -2.01 ml/min/1.73 m2/year, respectively) compared to patients with optimal ACR (0.08 ml/min/1.73 m2/year, p < 0.05). In patients with high normal ACR, age (standardized β、-0.30、p = 0.01), CV-HbA1c (standardized β、-0.66、p < 0.001) and CV-PMPG (standardized β、-0.27、p = 0.01) was associated with annual eGFR decline independently of mean HbA1c and PMPG, sex, BMI, waist circumference, diabetes duration and therapy, means and CVs of FPG and systolic blood pressure, baseline eGFR, log ACR and uses of anti-hypertensive medications (R2 = 0.47). In patients with elevated ACR, PMTG (standardized β、-0.408, p = 0.007) was associated with annual eGFR decline (R2 = 0.15).

CONCLUSIONS

Consistency of glycemic control and management of postprandial glycemia and lipidemia are important to preserve kidney function in type 2 diabetic patients.

Prevalent Rate of Nonalbuminuric Renal Insufficiency and Its Association with Cardiovascular Disease Event in Korean Type 2 Diabetes

BACKGROUND

Nonalbuminuric renal insufficiency is a unique category of diabetic kidney diseases. The objectives of the study were to evaluate prevalent rate of nonalbuminuric renal insufficiency and to investigate its relationship with previous cardiovascular disease (CVD) event in Korean patients with type 2 diabetes mellitus (T2DM).

METHODS

Laboratory and clinical data of 1,067 subjects with T2DM were obtained and reviewed. Study subjects were allocated into four subgroups according to the CKD classification. Major CVD events were included with coronary, cerebrovascular, and peripheral vascular events.

RESULTS

Nonalbuminuric stage ≥3 CKD group, when compared with albuminuric stage ≥3 CKD group, had shorter diabetic duration, lower concentrations of glycated hemoglobin, high density lipoprotein cholesterol, and high-sensitivity C-reactive protein, lower prevalent rates of retinopathy and previous CVD, and higher rate of treatment with angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Nonalbuminuric stage ≥3 CKD group showed a greater association with prior CVD events than no CKD group; however, albuminuric stage ≥3 CKD group made addition to increase prevalence of prior CVD events significantly when CKD categories were applied as covariates. Association of prior CVD events, when compared with normal estimated glomerular filtration rate (eGFR) and nonalbuminuria categories, became significant for declined eGFR, which was higher for eGFR of <30 mL/min/1.73 m², and albuminuria.

CONCLUSION

The results show that subjects with nonalbuminuric stage ≥3 CKD is significantly interrelated with occurrence of prior CVD events than those with normal eGFR with or without albuminuria. Comparing with normal eGFR and nonalbuminuria categories, the combination of increased degree of albuminuria and declined eGFR is becoming significant for the association of prior CVD events.

Foot insensitivity is associated with renal function decline in patients with type 2 diabetes: a cohort study

BACKGROUND

Identifying patients with diabetes at increased risk of chronic kidney disease (CKD) is essential to prevent/slow the progression to end-stage renal disease (ESRD). CKD and diabetic peripheral neuropathy (DPN) share common mechanisms. Hence, we aimed to examine the relationship between foot insensitivity and CKD in patients with Type 2 diabetes.

METHODS

A prospective observational cohort study in adults with Type 2 diabetes. Patients with ESRD were excluded. Foot insensitivity was assessed using the 10-g monofilament test. Renal function was assessed using estimated glomerular filtration rate (eGFR) based on the MDRD equation. Albuminuria was defined as the presence of urinary albumin/creatinine ratio (ACR) >3.4 mg/mmol.

RESULTS

Two hundred and twenty eight patients were recruited and followed-up for 2.5 years. One hundred and ninety patients (83.4%) had eGFR ≥ 60 ml/min/1.73 m². Seventy six (33.3%) patients had foot insensitivity (i.e. abnormal monofilament test). Patients with foot insensitivity had lower eGFR and higher prevalence of albuminuria compared to patients with normal monofilament test. After adjustment for age, gender, ethnicity, diabetes duration, HbA1c, body mass index, insulin treatment, number of anti-hypertensives, history of peripheral vascular disease, and baseline eGFR (R² 0.87), baseline foot insensitivity was associated with study-end eGFR (B = -3.551, p = 0.036).

CONCLUSIONS

Patients with Type 2 diabetes and foot insensitivity are at increased risk of eGFR decline. Identifying these patients offers an opportunity to intensify metabolic and blood pressure control to prevent/retard the development of CKD. Future studies of larger sample size and longer follow up from multiple centres are needed to assess the diagnostic performance of our findings in predicting CKD development, and to compare the performance of the monofilament test with albuminuria.