Renal outcome in type 2 diabetic patients with or without coexisting nondiabetic nephropathies

Clinico-pathological features of diabetic and non-diabetic renal diseases in type 2 diabetic patients: a retrospective study from a 10-year experience in a single center

AIM

To compare clinical and pathological characteristics as well as prognosis between diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) so as to explore potential diagnostic criteria of DN and provide some guidance for the treatment of type 2 diabetes mellitus (T2DM) patients with kidney involvement.

METHODS

T2DM patients with renal impairment who underwent kidney biopsy were included in this study, who were classified into 3 groups (DN, NDRD, DN with NDRD) based on their renal pathological diagnosis. Baseline clinical characteristics as well as follow-up data were collected and analyzed among 3 groups. Logistic regression was performed to determine the best predictors for DN diagnosis. Additional 34 MN patients without diabetes were enrolled by propensity score matching method to compare serum PLA2R antibody titer and kidney outcomes between diabetic MN patients and MN alone.

RESULTS

Among 365 patients with type 2 diabetes who underwent kidney biopsy, 179 (49.0%) patients were diagnosed with NDRD alone and 37 (10.1%) patients with NDRD combined DN. Risk factors for DN development in T2DM patients were longer time since diabetes diagnosis, higher level of serum creatinine, absence of hematuria and presence of diabetic retinopathy by multivariate analysis. Lower rate of proteinuria remission and higher risk of renal progression were observed in DN group compared with NDRD group. Membranous nephropathy was the most common NDRD in diabetic patients. There was no difference in serum PLA2R antibody positiveness or titer between MN patients with or without T2DM. There was lower remission rate but similar renal progression in diabetic MN when age, gender, baseline eGFR, albuminuria and IFTA score were adjusted.

CONCLUSIONS

Non-diabetic renal disease is not uncommon in T2DM patients with renal impairment, which has better prognosis with proper treatment. Coexisting diabetic status does not exert negative impact on renal progression in MN patients, and immunosuppressive agents should be administered when necessary.

Discovery of Novel Digital Biomarkers for Type 2 Diabetic Nephropathy Classification via Integration of Urinary Proteomics and Pathology

Background

The heterogeneous phenotype of diabetic nephropathy (DN) from type 2 diabetes complicates appropriate treatment approaches and outcome prediction. Kidney histology helps diagnose DN and predict its outcomes, and an artificial intelligence (AI)-based approach will maximize clinical utility of histopathological evaluation. Herein, we addressed whether AI-based integration of urine proteomics and image features improves DN classification and its outcome prediction, altogether augmenting and advancing pathology practice.

Methods

We studied whole slide images (WSIs) of periodic acid-Schiff-stained kidney biopsies from 56 DN patients with associated urinary proteomics data. We identified urinary proteins differentially expressed in patients who developed end-stage kidney disease (ESKD) within two years of biopsy. Extending our previously published human-AI-loop pipeline, six renal sub-compartments were computationally segmented from each WSI. Hand-engineered image features for glomeruli and tubules, and urinary protein measurements, were used as inputs to deep-learning frameworks to predict ESKD outcome. Differential expression was correlated with digital image features using the Spearman rank sum coefficient.

Results

A total of 45 urinary proteins were differentially detected in progressors, which was most predictive of ESKD (AUC=0.95), while tubular and glomerular features were less predictive (AUC=0.71 and AUC=0.63, respectively). Accordingly, a correlation map between canonical cell-type proteins, such as epidermal growth factor and secreted phosphoprotein 1, and AI-based image features was obtained, which supports previous pathobiological results.

Conclusions

Computational method-based integration of urinary and image biomarkers may improve the pathophysiological understanding of DN progression as well as carry clinical implications in histopathological evaluation.

Prevalence of Diabetic Retinopathy and Use of Common Oral Hypoglycemic Agents Increase the Risk of Diabetic Nephropathy-A Cross-Sectional Study in Patients with Type 2 Diabetes

OBJECTIVE

This study investigated the effect of amino acid metabolism on the risk of diabetic nephropathy under different conditions of the diabetic retinopathy, and the use of different oral hypoglycemic agents.

METHODS

This study retrieved 1031 patients with type 2 diabetes from the First Affiliated Hospital of Liaoning Medical University in Jinzhou, which is located in Liaoning Province, China. We conducted a spearman correlation study between diabetic retinopathy and amino acids that have an impact on the prevalence of diabetic nephropathy. Logistic regression was used to analyze the changes of amino acid metabolism in different diabetic retinopathy conditions. Finally, the additive interaction between different drugs and diabetic retinopathy was explored.

RESULTS

It is showed that the protective effect of some amino acids on the risk of developing diabetic nephropathy is masked in diabetic retinopathy. Additionally, the additive effect of the combination of different drugs on the risk of diabetic nephropathy was greater than that of any one drug alone.

CONCLUSIONS

We found that diabetic retinopathy patients have a higher risk of developing diabetic nephropathy than the general type 2 diabetes population. Additionally, the use of oral hypoglycemic agents can also increase the risk of diabetic nephropathy.

Development and validation of a novel nomogram to predict diabetic kidney disease in patients with type 2 diabetic mellitus and proteinuric kidney disease

PURPOSE

Differentiating between diabetic kidney disease (DKD) and non-diabetic kidney disease (NDKD) in patients with Type 2 diabetes mellitus (T2DM) is important due to implications on treatment and prognosis. Clinical methods to accurately distinguish DKD from NDKD are lacking. We aimed to develop and validate a novel nomogram to predict DKD in patients with T2DM and proteinuric kidney disease to guide decision for kidney biopsy.

METHODS

A hundred and two patients with Type 2 Diabetes Mellitus (T2DM) who underwent kidney biopsy from 1st January 2007 to 31st December 2016 were analysed. Univariate and multivariate analyses were performed to identify predictive variables and construct a nomogram. The discriminative ability of the nomogram was assessed by calculating the area under the receiver operating characteristic curve (AUROC), while calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test and calibration plot. Internal validation of the nomogram was assessed using bootstrap resampling.

RESULTS

Duration of T2DM, HbA1c, absence of hematuria, presence of diabetic retinopathy and absence of positive systemic biomarkers were found to be independent predictors of DKD in multivariate analysis and were represented as a nomogram. The nomogram showed excellent discrimination, with a bootstrap-corrected C statistic of 0.886 (95% CI 0.815-0.956). Both the calibration curve and the Hosmer-Lemeshow goodness-of-fit test (p = 0.242) showed high degree of agreement between the prediction and actual outcome, with the bootstrap bias-corrected curve similarly indicating excellent calibration.

CONCLUSIONS

A novel nomogram incorporating 5 clinical parameters is useful in predicting DKD in type 2 diabetes mellitus patients with proteinuric kidney disease.

Whether Renal Pathology Is an Independent Predictor for End-Stage Renal Disease in Diabetic Kidney Disease Patients with Nephrotic Range Proteinuria: A Biopsy-Based Study

Aims: To investigate whether renal pathology is an independent predictor for end-stage renal disease (ESRD) in diabetic kidney diseases (DKD) with nephrotic range proteinuria. Methods: A total of 199 DKD patients with nephrotic range proteinuria underwent renal biopsy and were divided into an ESRD group and a non-ESRD group. A Kaplan−Meier analysis was used to compare renal survival rate, and univariate and multivariate Cox proportional hazard analyses were used to determine the predictors of the ESRD. Results: The mean age of included patients was 51.49 ± 9.12 years and 113 patients (56.8%) progressed to ESRD. The median follow-up period was 16 (12−28) months. The glomerular pathology class III is the most common type (54.3%). In the Kaplan−Meier analysis, compared with patients without ESRD, patients with ESRD had a longer duration of diabetes (≥6 years), lower eGFR (<60 mL/min/1.73 m2), lower albumin (<30 g/L), lower hemoglobin (<120 g/L), and a higher grade of glomerular stage (class III + IV vs. class I + II) (p < 0.05). The hemoglobin and e-GFR, but not the histopathological damage, were significantly associated with a higher risk of ESRD in both the univariate and multivariate Cox analyses. Conclusions: In patients with diabetic kidney disease characterized by nephrotic range proteinuria, histopathological damage (glomerular alterations, interstitial fibrosis and tubular atrophy (IFTA), interstitial inflammation, and arteriolar hyalinosis) is not associated with poor renal outcomes, but hemoglobin and e-GFR could predict poor renal outcomes.

Rare Case of C3 Glomerulopathy in a Patient of Type 1 Diabetes Mellitus

Complement component 3 glomerulopathy (C3G) is a recently defined entity comprising dense deposit disease and C3 glomerulonephritis. It is associated with nonrenal diseases such as diabetes mellitus (DM) type 1, ocular drusen, acquired partial lipodystrophy, and monoclonal gammopathy of undetermined significance. We describe a case of 13-year-old boy of the known case of type 1 DM, who developed proteinuria, and swelling over his face, and lower limbs, which on renal biopsy, was diagnosed as a case of C3G.

New Diagnostic Model for the Differentiation of Diabetic Nephropathy From Non-Diabetic Nephropathy in Chinese Patients

BACKGROUND

The disease pathology for diabetes mellitus patients with chronic kidney disease (CKD) may be diabetic nephropathy (DN), non-diabetic renal disease (NDRD), or DN combined with NDRD. Considering that the prognosis and treatment of DN and NDRD differ, their differential diagnosis is of significance. Renal pathological biopsy is the gold standard for diagnosing DN and NDRD. However, it is invasive and cannot be implemented in many patients due to contraindications. This article constructed a new noninvasive evaluation model for differentiating DN and NDRD.

METHODS

We retrospectively screened 1,030 patients with type 2 diabetes who has undergone kidney biopsy from January 2005 to March 2017 in a single center. Variables were ranked according to importance, and the machine learning methods (random forest, RF, and support vector machine, SVM) were then used to construct the model. The final model was validated with an external group (338 patients, April 2017-April 2019).

RESULTS

In total, 929 patients were assigned. Ten variables were selected for model development. The areas under the receiver operating characteristic curves (AUCROCs) for the RF and SVM methods were 0.953 and 0.947, respectively. Additionally, 329 patients were analyzed for external validation. The AUCROCs for the external validation of the RF and SVM methods were 0.920 and 0.911, respectively.

CONCLUSION

We successfully constructed a predictive model for DN and NDRD using machine learning methods, which were better than our regression methods.

CLINICAL TRIAL REGISTRATION

ClinicalTrial.gov, NCT03865914.

Renal outcomes and prognostic factors in patients with type-2 diabetes and chronic kidney disease confirmed by renal biopsy

Aim

To evaluate the renal outcomes and prognostic factors among patients with type-2 diabetes (T2D) and biopsy-confirmed diabetic nephropathy (DN), non-diabetic renal disease (NDRD) and DN mixed with NDRD (MIX).

Design and Methods

Patients with both T2D and chronic kidney disease (CKD) who underwent renal biopsy between January 2014 and December 2016 were recruited in this prospective observational study. Participants were divided into DN group, NDRD group, or MIX group according to the baseline pathological diagnosis. The primary endpoint was a composite renal event of end-stage renal disease (ESRD) or ⩾ 40% reduction in estimated glomerular filtration rate (eGFR).

Results

Among the 292 participants included, 153 (52.4%) belonged to the DN group, 30 (10.3%) belonged to the NDRD group, and 109 (37.3%) belonged to the MIX group. During the median follow-up of 27 months, the adverse renal events occurred in 132 (44.2%) patients. Compared with NDRD group, the multiple adjusted hazard ratios (HRs) for renal events in patients with DN and MIX groups were 3.900 (95% confidence interval [CI]: 1.103-13.788) and 2.691 (95% CI: 0.662-10.936), respectively. Baseline lower eGFR (HR: 1.159, 95% CI: 1.060-1.266), severe proteinuria (HR: 2.047, 95% CI: 1.227-3.416), lower hemoglobin (HR: 1.170, 95% CI: 1.008-1.267), and a family history of diabetes (HR: 1.138, 95% CI: 1.008-2.285) were independent predictors for adverse renal outcomes in patients with DN.

Conclusion

In patients with T2D and CKD, pure DN and MIX group displayed a worse renal prognosis than NDRD group. Worse renal function, severe proteinuria, lower hemoglobin, and a family history of diabetes may be associated with adverse renal outcomes in patients with DN.

The predictive value of diabetic retinopathy on subsequent diabetic nephropathy in patients with type 2 diabetes: a systematic review and meta-analysis of prospective studies

This systematic review and meta-analysis aimed to assess the predictive value of diabetic retinopathy (DR) on further diabetic nephropathy (DN) risk in patients with type 2 diabetes (T2D) based on the prospective cohort studies. PubMed, Embase, and the Cochrane Library were systematically searched for eligible prospective cohort studies through March 2020. The predictive value of DR was assessed using sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) through the bivariate generalized linear mixed model and the random-effects model. Ten prospective cohort studies recruited 635 patients with T2D. The pooled sensitivity and specificity of DR for predicted DN were noted to be 0.64 (95% CI, 0.54–0.73) and 0.77 (95% CI, 0.60–0.88), respectively. The pooled PLR and NLR of DR for predicted DN were 2.72 (95% CI, 1.42–5.19) and 0.47 (95% CI, 0.33–0.67), respectively. The summary DOR for the relationship between DR and subsequent DN for T2D patients was 5.53 (95% CI, 2.00–15.30), and the AUC of DR for predicted DN was 0.73 (95% CI, 0.69–0.77). This study found significant associations between DR and subsequent DN risk for patients with T2D. Moreover, the predictive value of DR on subsequent DN risk was relatively lower.

Global Epidemiology, Health Outcomes, and Treatment Options for Patients With Type 2 Diabetes and Kidney Failure

The burden of type 2 diabetes and related complications has steadily increased over the last few decades and is one of the foremost global public health threats in the 21st century. Diabetes is one of the leading causes of chronic kidney disease and kidney failure and is an important contributor to the cardiovascular morbidity and mortality in this population. In addition, up to one in three patients who have received kidney transplants develop post-transplant diabetes, but the management of this common complication continues to pose a significant challenge for clinicians. In this review, we will describe the global prevalence and temporal trend of kidney failure attributed to diabetes mellitus in both developing and developed countries. We will examine the survival differences between treated kidney failure patients with and without type 2 diabetes, focusing on the survival differences in those on maintenance dialysis or have received kidney transplants. With the increased availability of novel hypoglycemic agents, we will address the potential impacts of these novel agents in patients with diabetes and kidney failure and in those who have developed post-transplant diabetes.

Kidney Biopsy in Type 2 Diabetes: A Multicenter Cross-Sectional Study

INTRODUCTION

Kidney biopsies (KBs) are performed in patients with type 2 diabetes (T2D) to diagnose non-diabetic or hypertensive kidney disease (NDHKD) potentially requiring specific management compared to diabetic and or hypertensive nephropathy (absence of NDHKD). Indications for KB are based on the presence of atypical features compared to the typical course of diabetic nephropathy. In this study, we assessed the association of different patterns of atypical features, or KB indications, with NDHKD.

METHODS

Native KBs performed in patients with T2D were analyzed. Data were collected from the patients' records. KB indications were determined according to the presence of different atypical features considered sequentially: (1) presence of any feature suggesting NDHKD which is not among the following ones, (2) recent onset of nephrotic syndrome, (3) low or rapidly declining estimated glomerular filtration rate (eGFR), (4) rapid increase in proteinuria, (5) short duration of diabetes, (6) presence of hematuria, or (7) normal retinal examination.

RESULTS

Among the 463 KBs analyzed, NDHKD was diagnosed in 40% of the total population and 54, 40, 24, and 7% of the KBs performed for indications 1-4 respectively. Conversely, no patient who underwent KB for indications 5-7 displayed NDHKD. Logistic regression analyses identified eGFRCKD-EPI >15 mL/min/1.73 m2, urinary protein-to-Cr ratio <0.3 g/mmol, hematuria, HbA1c <7%, and diabetes duration <5 years as predictors of NDHKD, independently from the indication group.

CONCLUSION

NDHKD is frequent in T2D. Despite the association of hematuria with NDHKD, our results suggest that presence of hematuria and absence of DR are insufficient to indicate KB in the absence of concurrent atypical features. Conversely, rapid progression of proteinuria and rapid deterioration of eGFR are major signals of NDHKD.

Primary glomerulonephritis in diabetic patients

BACKGROUND

Primary glomerulonephritis (PGN) has a significant part in non-diabetic kidney disease (NDKD) in diabetes mellitus (DM) patients. In our study, we compared the clinical, demographic and laboratory features of patients with biopsy-proven diabetic nephropathy (DN) and PGN with type 2 DM.

METHODS

In our retrospective study, type 2 DM patients who underwent kidney biopsy between 2011 and 2019 were included. Demographic, clinical and laboratory characteristics of DN and PGN patients were compared.

RESULTS

Seventy patients with a mean age of 55.7 ± 9.4 and 43 (61.4%) males were included. About 38 (54.3%) of the patients had DN and 32 (45.7%) had PGN. In the PGN, membranous GN (20, 62.5%) was most common. In DN patients, diabetes duration was longer; complications such as retinopathy, neuropathy, hypertension, coronary artery disease, heart failure were more frequent. At the time of renal biopsy, blood sugar, HbA1C, blood pressure, serum albumin and proteinuria values were similar in two groups. The pathological damage findings of kidney biopsy in DN patients were more severe. In the first year after kidney biopsy decrease in eGFR was higher in DN patients, whereas eGFR did not change in PGN patients.

CONCLUSION

In a diabetic patient, fasting blood sugar, hbA1C, serum albumin and proteinuria did not differ in the differential diagnosis of DN and PGN, whereas complications of DM (retinopathy, neuropathy, hypertension, coronary artery disease) were more characteristic in differentiation. Detection of PGN in a diabetic patient is crucial for the success of the treatment, according to DN.

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

AIMS

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Histopathologic and Clinical Features in Patients with Diabetes and Kidney Disease

BACKGROUND

The discovery of nondiabetic kidney disease (NDKD) in an individual patient with diabetes may have significant treatment implications. Extensive histopathologic data in this population are lacking, but they may provide insights into the complex pathogenesis of diabetic nephropathy (DN) and reveal specific phenotypes for the development of targeted therapies. This study seeks to elucidate the clinical and laboratory parameters associated with the spectrum of kidney histopathologic features in patients with diabetes.

METHODS

This study is a retrospective analysis of 399 kidney biopsies assessed from 2014 to 2016 at the University of Washington among patients with diabetes. More comprehensive clinical data were evaluated in a subset of 79 participants.

RESULTS

Of the 399 biopsies reviewed, 192 (48%) had a primary diagnosis of DN (including 26 with an additional diagnosis), and 207 (52%) had a primary diagnosis of NDKD (including 67 who also had DN). Retinopathy (sensitivity: 0.86; specificity: 0.81; OR, 27.1; 95% CI, 6.8 to 107.7) and higher levels of proteinuria (7.6 versus 4.1 g/d; P=0.004) were associated with DN, whereas a physician description of AKI was associated with a lower risk of DN (OR, 0.13; 95% CI, 0.04 to 0.38). The four most prevalent diagnoses in participants with NDKD were FSGS in 39, nephrosclerosis in 29, IgA nephropathy in 27, and acute tubular injury in 21.

CONCLUSIONS

Among patients with diabetes who undergo kidney biopsy in the Pacific Northwest, approximately half have DN, and half have NDKD. Retinopathy and more severe proteinuria were associated with DN, and AKI was a more common descriptor in NDKD.Podcast: This article contains a podcast at https://www.asnonline.org/media/podcast/K360/2020_11_25_KID0003962020.mp3.

Non-diabetic glomerular lesions in diabetic kidney disease: clinical predictors and outcome in an Eastern European cohort

PURPOSE

Since patients' prognosis depends on the lesions identified by kidney biopsy (KB), we aimed to evaluate predictors of non-diabetic kidney disease (NDKD) in diabetic subjects and to assess their kidney outcome as compared to diabetic nephropathy (DN).

METHODS

180 adults diagnosed by KB with DN (n = 120) or NDKD (n = 60), over a 10 year time-span, were retrospectively included and followed for a mean of 48.1 (95% CI 43.1-53.1) months. Patients with superimposed specific lesions over DN and with steroid-induced diabetes were excluded. The primary endpoint was renal replacement therapy (RRT) initiation. Only subjects who were alive at the end of follow-up (73 with DN and 38 with NDKD) entered the kidney survival analysis.

RESULTS

Membranous nephropathy (9%) was the most common NDKD. Predictors for NDKD were shorter duration of diabetes (OR 0.88; 95% CI 0.81-0.96, p = 0.004), absence of diabetic retinopathy (OR 0.08; 95% CI 0.01-0.44, p = 0.003), and nephrotic syndrome at presentation (OR 3.55; 95% CI 1.39-9.04, p = 0.008). Subjects with NDKD needed RRT later as those with DN [82 (95% CI 67-97.1) vs. 45 (95% CI 34-56.5) months, p = 0.001]. In an adjusted Cox model, biopsy diagnosed DN independently predicted RRT (OR 4.43; 95% CI 1.54-12.7, p = 0.006). Other predictors were lower eGFR, higher proteinuria, and absence of renin-angiotensin inhibitor therapy.

CONCLUSION

As one-third of the investigated subjects had NDKD, and NDKD was associated with a better kidney survival, independently predicted by the type of glomerular lesion, KB appears the most reliable tool to guide therapy and to assess outcome in patients with diabetic kidney disease.

A retrospective cohort study on the pathology and outcomes of type 2 diabetic patients with renal involvement

OBJECTIVE

To investigate the association of clinical and histological characteristics and the development of ESRD in T2DM patients with renal involvement.

METHODS

We conducted a retrospective analysis of clinical and pathologic data from T2DM patients who underwent renal biopsy (n = 120).

RESULTS

The mean age, duration of diabetes, and eGFR were 50.9 ± 11.2 years, 92.8 ± 41.3 months, 55.1 ± 42.3 mL/min/1.73 m², respectively. Among these patients, 57 (47.5%) were diagnosed with diabetic nephropathy (DN), and 63 (52.5%) with non-diabetic renal disease (NDRD). The most common subtype of NDRD is membranous nephropathy. Compared with the NDRD group, the DN group had a longer duration of diabetes, worse renal function, and a higher proportion of diabetic retinopathy. Kaplan-Meier analysis showed that the 5-year renal survival rate of the DN group was only 41%, whereas that of the NDRD group was 84%. ESRD was defined as eGFR below 15 mL/min/1.73 m². After multivariate adjustment, the risk of ESRD in DN patients was 3.81 times higher than that in NDRD patients. According to Glomerular Class, the 5-year renal survival rate of type IIA, IIB, III, and IV in the DN group was 88, 56, 28, and 15%, respectively. Kaplan-Meier analysis showed that there was a significant difference in renal survival among different glomerular classes or different interstitial fibrosis and tubular atrophy (IFTA) scores. But Cox proportional hazards analysis indicated that only IFTA score (HR 2.75, 95% CI 1.37-5.51, P = 0.001), but not the glomerular class (HR 1.21, 95% CI 0.73-2.00, P = 0.465), could predict renal outcome when adjusting for multivariate.

CONCLUSION

The prognosis of DN patients is significantly worse than that of NDRD patients. Compared with glomerular lesions, tubulointerstitial lesions were associated with higher risk for renal death in DN patients.

Insights into the Role of Renal Biopsy in Patients with T2DM: A Literature Review of Global Renal Biopsy Results

INTRODUCTION

Renal biopsy performed in patients with type 2 diabetes mellitus (T2DM) for atypical or suspected diabetic kidney disease (DKD) reveals one of three possibilities: diabetic nephropathy (DN, pathological diagnosis of DKD), nondiabetic kidney disease (NDKD) and DN plus NDKD (mixed form). NDKD (including the mixed form) is increasingly being recognized worldwide. With the emerging concept of DKD and the complexity of routine application of renal biopsy, the identification of "clinical indicators" to differentiate DKD from NDKD has been an area of active research.

METHODS

The PubMed database was searched for relevant articles mainly according to the keyword search method. We reviewed prevalence of the three types of DKD and different pathological lesions of NDKD. We also reviewed the clinical indicators used to identify DKD and NDKD.

RESULTS

The literature search identified 40 studies (5304 data) worldwide between 1977 and 2019 that looked at global renal biopsy and pathological NDKD lesions. The overall prevalence rate of DN, NDKD and DN plus NDKD is reported to be 41.3, 40.6 and 18.1%, respectively. In Asia, Africa (specifically Morocco and Tunisia) and Europe, the most common isolated NDKD pathological type is membranous nephropathy, representing 24.1, 15.1 and 22.6% of cases, respectively. In contrast, focal segmental glomerulosclerosis is reported to be the primary pathological type in North America (specifically the USA) and Oceania (specifically New Zealand), representing 22% and 63.9% of cases, respectively. Tubulointerstitial disease accounts for a high rate in the mixed group (21.7%), with acute interstitial nephritis being the most prevalent (9.3%), followed by acute tubular necrosis (9.0%). Regarding clinical indicators to differentiate DKD from NDKD, a total of 14 indicators were identified included in 42 studies. Among these, the most commonly studied indicators included diabetic retinopathy, duration of diabetes, proteinuria and hematuria. Regrettably, indicators with high sensitivity and specificity have not yet been identified.

CONCLUSION

To date, renal biopsy is still the gold standard to diagnose diabetes complicated with renal disease, especially when T2DM patients present atypical DKD symptoms (e.g. absence of diabetic retinopathy, shorter duration of diabetes, microscopic hematuria, sub-nephrotic range proteinuria, lower glycated hemoglobin, lower fasting blood glucose). We conclude that renal biopsy as early as possible is of great significance to enable personalized treatment to T2DM patients.

The Challenges of Using UK Renal Registry Data to Audit the Care of Patients with Diabetes on Renal Replacement Therapy

INTRODUCTION

Diabetes is a major cause of CKD and of mortality in patients on renal replacement therapy (RRT). Auditing the care of patients with diabetes on RRT against published guidelines relies on robust data collection.

OBJECTIVE

This article assesses the completeness of data items collected by the UK Renal Registry (UKRR) that are required to audit the care of patients with diabetes on RRT.

METHODS

The UKRR receives data on all patients receiving RRT in the UK. Patients with diabetes, diabetes type, and method of renal diagnosis were identified from primary renal disease (PRD) codes and comorbidity data for patients commencing RRT at one of the 57 renal centres in England and Wales between 2010 and 2016. The completeness of demographic and clinical data (blood pressure, cholesterol, glycated haemoglobin [HbA1c], and smoking status) was assessed for the first year of RRT.

RESULTS

Ninety-three per cent of all patients on RRT irrespective of diagnosis had a PRD code, but only 28/57 renal centres had comorbidity data completeness ≥70%; 34.9% of patients with diabetic nephropathy (DN) had type 1 diabetes, but this varied between centres (9.2-100%). Overall, 4.2% of DN diagnoses were by biopsy. Data completeness in the first year of RRT for cardiovascular risk factors ranged between 50.0 and 80.0%, with HbA1c data completeness being 63.0%. Of 57 centres, 20 had HbA1c data for ≥70% of patients in the first year of RRT.

CONCLUSIONS

There is persistent variation between renal centres in the completeness of data collected on patients with diabetes on RRT, impacting on the ability to undertake robust audit. Data linkages and expanded data permissions could see registry data play a key role in ongoing audit and research into patients with diabetes and CKD, provided adequate data can be collected.

The Value of Renal Biopsy in Non-Insulin-Dependent Diabetes Mellitus in Singapore over the Past Two Decades

Objective

This study on the prevalence of diabetic nephropathy (DN) and coexistence of non-diabetic renal disease (NDRD) in a cohort of 255 non-insulin-dependent diabetes mellitus (NIDDM) patients aims to determine the value of performing renal biopsies in these patients and elucidate the factors which could affect their progression to end-stage renal disease (ESRD).

Methods

Among 255 NIDDM patients, 93 had DN alone, 69 had NDRD alone, and the remaining 93 had DN plus NDRD (mixed group). The indications for renal biopsy were based on clinical suspicion of superimposed NDRD, including heavy or rapidly increasing proteinuria, renal impairment even though diabetes is of relatively short duration, rapidly declining renal function, and presence of hematuria with dysmorphic red blood cells suggesting presence of glomerulonephritis.

Results

The following were predictors of ESRD: high systolic BP at biopsy, longer duration of diabetes, heavy proteinuria, and presence of diabetic retinopathy. Comparing patients in the NDRD group with the DN group and the mixed group, the NDRD group had lower serum creatinine and higher eGFR with lower urinary proteinuria and higher serum albumin at presentation and on follow-up. Kimmelstiel-Wilson nodules were associated with a poorer prognosis leading to a higher occurrence of ESRD among patients with DN.

Conclusion

Renal biopsy is of value in indicating the prognosis of NIDDM patients with DN based on the diabetic lesions. For NIDDM patients with atypical course and suspicion of associated NDRD, a renal biopsy would enable us to diagnose the underlying NDRD and offer appropriate therapy. Most nephrologists would consider renal biopsy for an NIDDM patient based on clinical indications like atypical clinical course and suspicion of an associated NDRD, but they would not perform a routine renal biopsy like for a CKD patient, unless it is for a research indication.

Design and validation of a scoring model for differential diagnosis of diabetic nephropathy and nondiabetic renal diseases in type 2 diabetic patients

BACKGROUND

We aim to design a scoring model for differential diagnosis between diabetic nephropathy (DN) and nondiabetic renal disease (NDRD) in type 2 diabetic patients through a combination of clinical variables.

METHODS

A total of 170 patients with type 2 diabetes who underwent kidney biopsies were included and divided into three groups according to pathological findings: DN group (n = 46), MIX group (DN + NDRD, n = 54), NDRD group (n = 70). Clinical characteristics and laboratory data were collected and compared among groups. Variables with a significant statistical difference between DN and NDRD patients were analyzed by logistic regression to predict the presence of NDRD; then a scoring model was established based on the regression coefficient and further validated in an independent cohort of 67 patients prospectively.

RESULTS

On biopsy, 72.9% of patients had NDRD, and the most common pathological type was membranous nephropathy. The established scoring model for predicting NDRD included five predictors: age, systolic blood pressure, hemoglobin, duration of diabetes, and absence of diabetic retinopathy. The model demonstrated good discrimination and calibration (area under curve [AUC] 0.863, 95% CI, 0.800-0.925; Hosmer-Lemeshow [H-L] P = .062). Furthermore, high prediction accuracy (AUC = 0.900; 95% CI, 0.815-0.985) in the validation cohort proved the stability of the model.

CONCLUSIONS

We present a simple, robust scoring model for predicting the presence of NDRD with high accuracy (0.85) for the first time. This decision support tool provides a noninvasive method for differential diagnosis of DN and NDRD, which may help clinicians assess the risk-benefit ratio of kidney biopsy for type 2 diabetic patients with renal impairment.

Development and validation of a predictive model for end-stage renal disease risk in patients with diabetic nephropathy confirmed by renal biopsy

This study was performed to develop and validate a predictive model for the risk of end-stage renal disease (ESRD) inpatients with diabetic nephropathy (DN) confirmed by renal biopsy. We conducted a retrospective study with 968 patients with T2DM who underwentrenal biopsy for the pathological confirmation of DNat the First Affiliated Hospital of Zhengzhou University from February 2012 to January 2015; the patients were followed until December 2018. The outcome was defined as a fatal or nonfatal ESRD event (peritoneal dialysis or hemodialysis for ESRD, renal transplantation, or death due to chronic renal failure or ESRD). The dataset was randomly split into development (75%) and validation (25%) cohorts. We used stepwise multivariablelogistic regression to identify baseline predictors for model development. The model’s performance in the two cohorts, including discrimination and calibration, was evaluated by the C-statistic and the P value of the Hosmer-Lemeshow test. During the 3-year follow-up period, there were 225 outcome events (47.1%) during follow-up. Outcomes occurred in 187 patients (52.2%) in the derivation cohort and 38 patients (31.7%) in the validation cohort. The variables selected in the final multivariable logistic regression after backward selection were pathological grade, Log Urinary Albumin-to-creatinine ratio (Log ACR), cystatin C, estimated glomerular filtration rate (eGFR) and B-type natriuretic peptide (BNP). 4 prediction models were created in a derivation cohort of 478 patients: a clinical model that included cystatin C, eGFR, BNP, Log ACR; a clinical-pathological model and a clinical-medication model, respectively, also contained pathological grade and renin-angiotensin system blocker (RASB) use; and a full model that also contained the pathological grade, RASB use and age. Compared with the clinical model, the clinical-pathological model and the full model had better C statistics (0.865 and 0.866, respectively, vs. 0.864) in the derivation cohort and better C statistics (0.876 and 0.875, respectively, vs. 0.870) in the validation cohort. Among the four models, the clinical-pathological model had the lowest AIC of 332.53 and the best P value of 0.909 of the Hosmer-Lemeshow test. We constructed a nomogram which was a simple calculator to predict the risk ratio of progression to ESRD for patients with DN within 3 years. The clinical-pathological model using routinely available clinical measurements was shown to be accurate and validated method for predicting disease progression in patients with DN. The risk model can be used in clinical practice to improve the quality of risk management and early intervention.

Risk factors for non-diabetic renal disease in diabetic patients

Background

Diabetic patients with kidney disease have a high prevalence of non-diabetic renal disease (NDRD). Renal and patient survival regarding the diagnosis of diabetic nephropathy (DN) or NDRD have not been widely studied. The aim of our study is to evaluate the prevalence of NDRD in patients with diabetes and to determine the capacity of clinical and analytical data in the prediction of NDRD. In addition, we will study renal and patient prognosis according to the renal biopsy findings in patients with diabetes.

Methods

Retrospective multicentre observational study of renal biopsies performed in patients with diabetes from 2002 to 2014.

Results

In total, 832 patients were included: 621 men (74.6%), mean age of 61.7 ± 12.8 years, creatinine was 2.8 ± 2.2 mg/dL and proteinuria 2.7 (interquartile range: 1.2–5.4) g/24 h. About 39.5% (n = 329) of patients had DN, 49.6% (n = 413) NDRD and 10.8% (n = 90) mixed forms. The most frequent NDRD was nephroangiosclerosis (NAS) (n = 87, 9.3%). In the multivariate logistic regression analysis, older age [odds ratio (OR) = 1.03, 95% CI: 1.02–1.05, P < 0.001], microhaematuria (OR = 1.51, 95% CI: 1.03–2.21, P = 0.033) and absence of diabetic retinopathy (DR) (OR = 0.28, 95% CI: 0.19–0.42, P < 0.001) were independently associated with NDRD. Kaplan–Meier analysis showed that patients with DN or mixed forms presented worse renal prognosis than NDRD (P < 0.001) and higher mortality (P = 0.029). In multivariate Cox analyses, older age (P < 0.001), higher serum creatinine (P < 0.001), higher proteinuria (P < 0.001), DR (P = 0.007) and DN (P < 0.001) were independent risk factors for renal replacement therapy. In addition, older age (P < 0.001), peripheral vascular disease (P = 0.002), higher creatinine (P = 0.01) and DN (P = 0.015) were independent risk factors for mortality.

Conclusions

The most frequent cause of NDRD is NAS. Elderly patients with microhaematuria and the absence of DR are the ones at risk for NDRD. Patients with DN presented worse renal prognosis and higher mortality than those with NDRD. These results suggest that in some patients with diabetes, kidney biopsy may be useful for an accurate renal diagnosis and subsequently treatment and prognosis.

When to perform renal biopsy in patients with type2 diabetes mellitus? Predictive model of non-diabetic renal disease

INTRODUCTION

Diabetic nephropathy (DN) is one of the most frequent complications in patients with diabetes mellitus (DM) and its diagnosis is usually established on clinical grounds. However, kidney involvement in some diabetic patients can be due to other causes, and renal biopsy might be needed to exclude them. The aim of our study was to establish the clinical and analytical data that predict DN and no-diabetic renal disease (NDRD), and to develop a predictive model (score) to confirm or dismiss DN.

MATERIAL AND METHODS

We conducted a transversal, observational and retrospective study, including renal biopsies performed in type2 DM patients, between 2000 and 2018.

RESULTS

Two hundred seven DM patients were included in our study. The mean age was 64.5±10.6 years and 74% were male. DN was found in 126 (61%) of the biopsies and NDRD in 81 (39%). Diabetic retinopathy was presented in 58% of DN patients, but only in 6% of NDRD patients (P<.001). Patients with NDRD were diagnosed of primary glomerulopathies (52%), nephroangiosclerosis (16%), inmunoallergic interstitial nephritis (15%) and vasculitis (8.5%). In the multivariate analysis, retinopathy (OR26.7; 95%CI: 6.8-104.5), chronic ischaemia of lower limbs (OR4,37; 95%CI: 1.33-14.3), insulin therapy (OR3.05; 95%CI: 1.13-8.25), time course of DM ≥10years (OR2.71; 95%CI: 1.1-6.62) and nephrotic range proteinuria (OR2.91; 95%CI: 1.2-7.1) were independent predictors for DN. Microhaematuria defined as ≥10 red blood cells per high-power field (OR0.032; 95%CI: 0.01-0.11) and overweight (OR0.21; 95%CI: 0.08-0.5) were independent predictors of NDRD. According to the predictive model based on the multivariate analysis, all patients with a score >3 had DN and 94% of cases with a score ≤1 had NDRD (score ranked from -6 to 8points).

CONCLUSIONS

NDRD is common in DM patients (39%), being primary glomerulonephritis the most frequent ethology. The absence of retinopathy and the presence of microhematuria are highly suggestive of NDRD. The use of our predictive model could facilitate the indication of performing a renal biopsy in DM patients.

A Differential Diagnosis Model For Diabetic Nephropathy And Non-Diabetic Renal Disease In Patients With Type 2 Diabetes Complicated With Chronic Kidney Disease

PURPOSE

Differentiating between diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) is difficult and inefficient. The aim of the present study was to create a model for the differential diagnosis of DN and NDRD in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

We consecutively screened 213 patients with T2DM complicated with chronic kidney disease, who underwent renal biopsy at The First Affiliated Hospital of Guangxi Medical University (Nanning, China) between 2011 and 2017. According to the pathological results derived from the renal biopsy, the patients were divided into three groups (74, 130, and nine in the DN, NDRD, and NDRD superimposed with DN group, respectively). Clinical and laboratory data were compared and a diagnostic model was developed based on the following logistic regression model: logit(P)=+++ … +.

RESULTS

We observed a high incidence of NDRD (61.0% of all patients), including various pathological types; the most common type was idiopathic membranous nephropathy. By comparing clinical variables, we identified a number of differences between DN and NDRD. Logistic regression analyses showed that the following variables were statistically significant: the absence of diabetic retinopathy (DR), proteinuria within the non-nephrotic range, the absence of anemia and an estimated glomerular filtration rate (eGFR) ≥90 mL/min/1.73 m2. We subsequently constructed a diagnostic model for predicting NDRD, as follows: PNDRD=1/[1+exp(-17.382-3.339×DR-1.274×Proteinuria-2.217×Anemia-1.853×eGFR-0.993×DM+20.892Bp)]. PNDRD refers to the probability of a diagnosis of NDRD (a PNDRD≥0.5 predicts NDRD while a PNDRD <0.5 predicts DN); while DM refers to the duration of diabetes. This model had a sensitivity of 95.4%, a specificity of 83.8%, and the area under the receiver operating characteristic curve was 0.925.

CONCLUSION

Our diagnostic model may facilitate the clinical differentiation of DN and NDRD, and assist physicians in developing more effective and rational criteria for kidney biopsy in patients with T2DM complicated with chronic kidney disease.

CKD in diabetes: diabetic kidney disease versus nondiabetic kidney disease

The increasing global prevalence of type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) has prompted research efforts to tackle the growing epidemic of diabetic kidney disease (DKD; also known as diabetic nephropathy). The limited success of much of this research might in part be due to the fact that not all patients diagnosed with DKD have renal dysfunction as a consequence of their diabetes mellitus. Patients who present with CKD and diabetes mellitus (type 1 or type 2) can have true DKD (wherein CKD is a direct consequence of their diabetes status), nondiabetic kidney disease (NDKD) coincident with diabetes mellitus, or a combination of both DKD and NDKD. Preclinical studies using models that more accurately mimic these three entities might improve the ability of animal models to predict clinical trial outcomes. Moreover, improved insights into the pathomechanisms that are shared by these entities - including sodium-glucose cotransporter 2 (SGLT2) and renin-angiotensin system-driven glomerular hyperfiltration and tubular hyper-reabsorption - as well as those that are unique to individual entities might lead to the identification of new treatment targets. Acknowledging that the clinical entity of CKD plus diabetes mellitus encompasses NDKD as well as DKD could help solve some of the urgent unmet medical needs of patients affected by these conditions.

Identification of clinical predictors of diabetic nephropathy and non-diabetic renal disease in Chinese patients with type 2 diabetes, with reference to disease course and outcome

AIMS

To determine the prevalence of diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) in patients with type 2 diabetes mellitus (T2DM), and the important clinical predictors of renal outcome and clinical course.

METHODS

We conducted a retrospective analysis of clinical, laboratory, and histopathologic data from T2DM patients with renal involvement confirmed by renal biopsy (n = 505). The outcome was defined as the progression to end-stage renal disease (ESRD).

RESULTS

Renal biopsy revealed that 302 patients (59.8%) had DN, 174 (34.5%) had NDRD, and 29 (5.7%) had NDRD superimposed on DN. In multivariate analysis, the absence of diabetic retinopathy (DR) (odds ratio (OR) 4.171, 95% confidence interval (CI) 1.810-9.612; P = 0.001), absence of hypertension (OR 2.412, 95% CI 1.095-5.315; P = 0.029), shorter duration of diabetes (OR 1.015, 95% CI 1.008-1.022; P < 0.001), lower-risk chronic kidney disease (CKD) heat map category (green, yellow and orange) (OR 3.885, 95% CI 1.289-11.707; P = 0.016) and lower glycated hemoglobin (HbA1c) (OR 1.339, 95% CI 1.114-1.610; P = 0.002) were significant clinical predictors of NDRD. Patients with DN had a poorer 5-year renal outcome than those with NDRD, and multivariate analysis identified DN as an independent risk factor for progression to ESRD, when adjusted for important clinical variables (P < 0.05).

CONCLUSIONS

This study has identified the absence of DR and hypertension, lower-risk CKD heat map category, shorter duration of diabetes, and lower HbA1c as useful clinical predictors of NDRD. Renal biopsy is recommended for patients with T2DM and renal disease to obtain an accurate diagnosis and determine timely disease-specific treatment, which should increase the chance of a good renal outcome.

Histologic predictors of renal outcome in diabetic nephropathy: Beyond renal pathology society classification

The prognostic utility of histologic features in patients with diabetic nephropathy (DN) classified according to the Renal Pathology Society (RPS) classification is controversial. Therefore, we aimed to evaluate the relationship between histologic changes and renal outcome in DN patients.We examined the renal outcome at November 30, 2017 of 74 adult patients (median age of 54.6 years, 69% male, 81% diabetes mellitus (DM) type 2, estimated GFR (eGFR) 29.6 mL/min) with biopsy proven DN between 2010 and 2015. The primary endpoint was renal replacement therapy (RRT) initiation.Half of the patients progressed to end stage renal disease (ESRD) during follow-up; they had lower eGFR, increased proteinuria, hematuria and serum cholesterol. Regarding the pathologic features, they were more frequently in class III and IV, had higher interstitial fibrosis and tubular atrophy score (IFTA), increased interstitial inflammation, more frequent arteriolar hyalinosis and higher glomerular basement membrane (GBM) thickness. The mean kidney survival time was 2.7 (95%CI 2.1, 3.3) years. In univariate time-dependent analyses, higher RPS DN class, increased IFTA, the presence of arteriolar hyalinosis and arteriosclerosis were associated with RRT initiation.In the fully adjusted model, the clinical characteristics associated with poor renal survival were longer duration of DM, lower eGFR, increased proteinuria and higher hematuria and the only pathologic lesions to remain significant were the GBM thickness and the IFTA.In conclusion, in this European cohort, the severity of glomerular lesions evaluated with the RPS DN classification had limited utility in predicting RRT initiation. However, IFTA and GBM thickness were significantly associated with renal survival.

Diagnostic Performance of Retinopathy in the Detection of Diabetic Nephropathy in Type 2 Diabetes: A Systematic Review and Meta-Analysis of 45 Studies

AIMS

To conduct an evidence-based evaluation of diabetic retinopathy (DR) for the diagnosis of diabetic nephropathy (DN) in type 2 diabetics with kidney disease.

METHODS

We systematically searched PubMed, EMBASE, and the Cochrane Library from inception to June 27, 2018, including the reference lists of identified primary studies. A study was included if it (1) used DR as a diagnostic test for DN; and (2) used histological evaluation of renal tissues as the reference standard.

RESULTS

The analysis included 45 studies (4,561 patients). A bivariate analysis yielded a sensitivity of 0.67 (95% CI 0.61-0.74) and a specificity of 0.78 (95% CI 0.73-0.82). The summary receiver operating characteristic curve analysis provided an area under the curve (AUC) of 0.79 (95% CI 0.76-0.83). In a setting of 41% prevalence of DN, the probability of DN would be 68% if the test of DR was positive, and the probability of DN would be 23% if it was negative. In addition, although the mean specificity of proliferative DR for the detection of DN was 0.99 (95% CI 0.45-1.00), the mean sensitivity was 0.34 (95% CI 0.24-0.44), and the AUC was 0.58 (95% CI 0.53-0.62).

CONCLUSIONS

DR is helpful in diagnosing DN in persons with type 2 diabetes and kidney disease, but the severity of DR may not parallel the presence of DN.

Meta-Analysis of Diagnostic Accuracy of Retinopathy for the Detection of Diabetic Kidney Disease in Adults With Type 2 Diabetes

OBJECTIVES

The study aimed to explore whether diabetic retinopathy (DR) could distinguish diabetic kidney disease (DKD) from nondiabetic renal diseases (NDRDs) in patients with type 2 diabetes mellitus and renal disease.

METHODS

We searched PubMed, Embase, Cochrane, MEDLINE and China National Knowledge Internet for articles that enrolled patients with DKD and NDRD. The results were summarized as sensitivity, specificity and the area under the curve of summary receiver operating characteristic curve with their 95% confidence intervals (CIs).

RESULTS

A total of 51 studies that included 4,990 participants were collected for evaluation. The overall pooled sensitivity, specificity and area under the curve with their 95% CIs were 0.67 (95% CI 0.61, 0.73), 0.77 (95% CI 0.72, 0.81) and 0.78 (95% CI 0.75 to 0.82), respectively. If the test for DR is negative, the probability of DKD would decrease to 10%, but if the test for DR is positive, the probability would increase only to 42%. In addition, although the mean specificity of proliferative DR for detection of DKD was 0.98 (95% CI 0.92 to 1.00), the mean sensitivity was 0.25 (95% CI 0.16, 0.35).

CONCLUSIONS

DR may lack adequate evidence either to verify DKD or to exclude NDRD, and the severity of DR may not parallel the presence of DKD.

Clinicopathological Features of Nondiabetic Renal Diseases from Different Age Groups: An Observational Cross-sectional Study

Background

Diabetes mellitus (DM) has become the leading cause of chronic kidney disease (CKD). Nondiabetic renal diseases (NDRDs) have different clinicopathological features and prognosis from those of diabetic nephropathy. Our study sought to analyze the clinical and pathological features of NDRDs, in different age groups through a cross-sectional study.

Methods

All patients with type 2 DM at our center who underwent renal biopsy between March 1997 and March 2017 were screened and divided into three groups by age: Group 1 (youth group), 18-44 years old; Group 2 (middle-aged group), 45-59 years old; and Group 3 (elderly group), ≥60 years old. We analyzed the clinicopathological data and risk factors by univariate and multivariate logistic regression for NDRD of the patients to identify the features of NDRD in different age groups.

Results

We included 982 patients in the final analysis. Patients with NDRD accounted for 64.4% of all patients. IgA nephropathy (IgAN) was the most common pathological pattern in young patients with NDRD, accounting for 26.3%. In the middle-aged group, the two most common pathological patterns were IgAN and membranous nephropathy. Membranous nephropathy was the most common pathological pattern in elderly patients with NDRD, accounting for 29.3%. Consistent with pathological features, glomerular hematuria is a risk factor for NDRD in Group 1 (odds ratio [OR], 26.514; 95% confidence interval [CI], 2.503-280.910; P = 0.006). On the other hand, rapidly increasing proteinuria or nephrotic syndrome is a risk factor for NDRD in Group 2 (OR, 5.921; 95% CI, 2.061-17.013; P = 0.001) and Group 3 (OR, 90.409; 95% CI, 6.198-1318.826; P = 0.001).

Conclusions

This single-center study showed that the proportion and composition of NDRD differ among different age groups. Consistent with pathological features, some clinical indices such as hematuria and proteinuria showed different features among different age groups.

Clinical outcomes in patients with biopsy-proved diabetic nephropathy compared to isolated lupus or crescentic glomerulonephritis

AIMS

Diabetic nephropathy (DMN) is usually diagnosed clinically without pathology, and the prognosis of which compared to non-diabetic renal diseases has rarely been investigated especially in ethnic Chinese population. Here we reported the outcome of patients with biopsy-proved DMN compared to those with isolated crescentic glomerulonephritis (GN) or lupus nephritis (LN).

METHODS

This retrospective observational study included patients with DMN (n = 55), crescentic GN (n = 48) and LN (n = 82) from an original cohort of 987 adult patients who underwent kidney biopsy. The median follow-up period was 8.3 years. The Cox regression model was used to identify factors associated with the outcome measures of end-stage renal disease (ESRD) and all-cause mortality.

RESULTS

Patients with DMN and crescentic GN exhibited higher rates of ESRD than LN group (65.5%, 66.7% versus 32.9%, p < 0.001). After accounting for the competing risk of death, DMN versus LN, along with lower hemoglobin values, lower estimated glomerular filtration rates and severe proteinuria were independent predictors for ESRD. Patients with DMN and crescentic GN displayed higher mortality rates than LN patients following the development of ESRD (38.2% and 29.2% versus 9.8%, p < 0.001). Multivariate analysis showed old age (≧65 years) and lower serum albumin levels were independently associated with overall death.

CONCLUSIONS

Patients with biopsy-proved DMN, but not crescentic GN, showed a greater risk of ESRD than LN counterparts. Given the grave renal prognosis of DMN, more meticulous follow-up is critical to ensure that best therapeutic strategies are used to avert progression to ESRD.

Renal Histology in Diabetic Patients

Background:

The diagnosis of diabetic nephropathy is based on the course of clinical manifestations and renal biopsy. Renal biopsy is usually performed in patients with atypical presentations.

Objectives:

This study was performed to analyze various renal histopathological lesions in diabetic patients and to establish a clinicopathological correlation.

Materials and Methods:

In this retrospective study, the authors analyzed renal histology of 40 patients with type 2 diabetes mellitus who presented with atypical features of diabetic renal involvement and underwent renal biopsy at the Military Hospital Mohammed V, Rabat, Morocco, between January 2008 and December 2016.

Results:

About 60% of the patients had isolated diabetic nephropathy, 35% had isolated nondiabetic renal diseases and 5% had both. Patients with nondiabetic renal diseases had significantly higher hematuria (P = 0.02), shorter duration of diabetes (P = 0.009), higher mean estimated glomerular filtration rate (P = 0.04) and lower prevalence of diabetic retinopathy (P < 0.001). The most common histological lesion in patients with nondiabetic renal diseases was IgA nephropathy (25%). In patients with diabetic nephropathy, the most common histological class was Class III (42.3%). Furthermore, higher histological classes were associated with lower estimated glomerular filtration rate (P < 0.001) as well as higher prevalence of diabetic retinopathy (P = 0.009) and nephrotic proteinuria (P = 0.04).

Conclusions:

This study found that in Rabat, Morocco, the most common histopathological lesion in patients with diabetes was diabetic nephropathy. Hematuria, shorter duration of diabetes, higher mean estimated glomerular filtration rate and lower prevalence of diabetic retinopathy were reported among those with nondiabetic renal diseases. These findings are in accord with that of studies from other countries. However, large sample size and long-term follow-up clinical studies are needed to demonstrate the renal pathological implications and renal outcomes in type 2 diabetes mellitus patients with renal involvement.

Progression of diabetic kidney disease and trajectory of kidney function decline in Chinese patients with Type 2 diabetes

Diabetes is a major cause of end stage renal disease (ESRD), yet the natural history of diabetic kidney disease is not well understood. We aimed to identify patterns of estimated GFR (eGFR) trajectory and to determine the clinical and genetic factors and their associations of these different patterns with all-cause mortality in patients with type 2 diabetes. Among 6330 patients with baseline eGFR >60 ml/min per 1.73 m² in the Hong Kong Diabetes Register, a total of 456 patients (7.2%) developed Stage 5 chronic kidney disease or ESRD over a median follow-up of 13 years (incidence rate 5.6 per 1000 person-years). Joint latent class modeling was used to identify different patterns of eGFR trajectory. Four distinct and non-linear trajectories of eGFR were identified: slow decline (84.3% of patients), curvilinear decline (6.5%), progressive decline (6.1%) and accelerated decline (3.1%). Microalbuminuria and retinopathy were associated with accelerated eGFR decline, which was itself associated with all-cause mortality (odds ratio [OR] 6.9; 95% confidence interval [CI]: 5.6-8.4 for comparison with slow eGFR decline). Of 68 candidate genetic loci evaluated, the inclusion of five loci (rs11803049, rs911119, rs1933182, rs11123170, and rs889472) improved the prediction of eGFR trajectories (net reclassification improvement 0.232; 95% CI: 0.057--0.406). Our study highlights substantial heterogeneity in the patterns of eGFR decline among patients with diabetic kidney disease, and identifies associated clinical and genetic factors that may help to identify those who are more likely to experience an accelerated decline in kidney function.

Non-diabetic renal disease in patients with type 2 diabetes: a single centre study

BACKGROUND

Non-diabetic renal disease (NDRD) has been widely known in diabetic patients. The clinical differentiation between diabetic nephropathy (DN) and NDRD is still not so clear and effective.

AIM

To analyse the pathological characteristics and distribution of renal injury in selected type 2 diabetic patients. Comparison between DN and NDRD in clinical characteristics, to find important predictors for NDRD.

METHODS

To conduct retrospective analysis of clinical, laboratory and pathohistological data of type 2 diabetic patients in whom renal biopsies were performed from March 2010 to September 2014 in Shandong Provincial Hospital affiliated to Shandong University (n = 88).

RESULTS

According to the findings of renal biopsy, the incidences of DN, NDRD and DN complicated with NDRD were 20.46, 72.73 and 6.82% respectively. The most common NDRD found were: membranous nephropathy, followed by IgA nephropathy and focal segmental glomerulosclerosis. In multivariate logistic-analysis, fasting blood glucose (odds ratio (OR) 0.714; 95% confidence interval (CI) = 0.543-0.939; P = 0.016) and absence of diabetic retinopathy (OR 18.602; 95% CI = 2.176-159.018; P = 0.003) were independent predictors of NDRD.

CONCLUSIONS

This study confirmed a considerably high prevalence of NDRD in type 2 diabetic patients with renal injury. As some cases of NDRD are readily treatable or remittable, we should consider renal biopsy in selected diabetic patients with renal involvement, especially in those with effective blood glucose control and the absence of diabetic retinopathy.

Accuracy of hematuria for predicting non-diabetic renal disease in patients with diabetes and kidney disease: A systematic review and meta-analysis

AIMS

To clarify the predictive value of hematuria in patients with diabetes and non-diabetic renal disease (NDRD).

METHODS

The databases of Medline, Embase and the Cochrane Library were searched up to November 22, 2017. The pooled sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic (SROC) curve (AUC) were calculated using a bivariate mixed-effects regression model.

RESULTS

Thirty-eight articles were eligible, of which 35 articles with 4005 patients investigated hematuria. The pooled sensitivity and specificity of hematuria to predict NDRD were 0.42 (95% CI 0.35-0.49) and 0.72 (95% CI 0.64-0.79), respectively. The pooled PLR and NLR were 1.49 (95% CI 1.28-1.75) and 0.81 (95% CI 0.75-0.87), respectively. The DOR was 1.85 (95% CI 1.49-2.30). The pooled AUC was 0.59 (95% CI 0.54-0.63). For dysmorphic erythrocytes, the pooled sensitivity was 0.27 (95% CI 0.23-0.32), while the specificity was 0.94 (95% CI 0.91-0.97). There was heterogeneity among studies (p < 0.001), and no publication bias was identified.

CONCLUSIONS

Type 2 diabetes patients presenting with hematuria are slightly more likely to develop NDRD. Dysmorphic erythrocytes may be more useful than microhematuria in diagnosing for NDRD in type 2 diabetes with proteinuria.

Hematuria and Renal Outcomes in Patients With Diabetic Chronic KidneyDisease

BACKGROUND

Hematuria may indicate nondiabetic renal disease in diabetic chronic kidney disease (CKD). However, some studies have reported that hematuria is noted in diabetic nephropathy and is associated with albuminuria. Hematuria is a risk factor for end-stage renal disease in glomerulonephritis, but its prognostic value in diabetic CKD is unknown. We investigated the factors associated with hematuria and the prognostic value of hematuria in patients with diabetic CKD.

MATERIAL AND METHODS

We included 1958 patients with type 2 diabetes and CKD stages 1-5, and 111 patients underwent renal biopsy. Patients in the biopsied cohort were younger and had more severe proteinuria, compared with those in the total cohort; hematuria was associated with nondiabetic renal disease.

RESULTS

In the total cohort, hematuria was observed in 15.0% of the patients and was associated with young age, a lower estimated glomerular filtration rate, proteinuria, high blood pressure and short diabetes duration. Hematuria was significantly associated with an increased risk (hazard ratio 1.39, 95% CI: 1.10-1.76, P < 0.001) of end-stage renal disease, particularly in patients with CKD stages 1-3 or a urine protein-to-creatinine ratio of <1,500mg/g (P for interaction < 0.05). The odds ratio of hematuria for rapid renal progression was 1.81 (95% CI: 1.29-2.53, P < 0.001).

CONCLUSIONS

Hematuria is associated with nondiabetic renal disease in biopsied patients with diabetic CKD and is associated with an increased risk of end-stage renal disease in patients with early diabetic CKD.

Value of adding the renal pathological score to the kidney failure risk equation in advanced diabetic nephropathy

BACKGROUND

There have been a limited number of biopsy-based studies on diabetic nephropathy, and therefore the clinical importance of renal biopsy in patients with diabetes in late-stage chronic kidney disease (CKD) is still debated. We aimed to clarify the renal prognostic value of pathological information to clinical information in patients with diabetes and advanced CKD.

METHODS

We retrospectively assessed 493 type 2 diabetics with biopsy-proven diabetic nephropathy in four centers in Japan. 296 patients with stage 3-5 CKD at the time of biopsy were identified and assigned two risk prediction scores for end-stage renal disease (ESRD): the Kidney Failure Risk Equation (KFRE, a score composed of clinical parameters) and the Diabetic Nephropathy Score (D-score, a score integrated pathological parameters of the Diabetic Nephropathy Classification by the Renal Pathology Society (RPS DN Classification)). They were randomized 2:1 to development and validation cohort. Hazard Ratios (HR) of incident ESRD were reported with 95% confidence interval (CI) of the KFRE, D-score and KFRE+D-score in Cox regression model. Improvement of risk prediction with the addition of D-score to the KFRE was assessed using c-statistics, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

During median follow-up of 1.9 years, 194 patients developed ESRD. The cox regression analysis showed that the KFRE,D-score and KFRE+D-score were significant predictors of ESRD both in the development cohort and in the validation cohort. The c-statistics of the D-score was 0.67. The c-statistics of the KFRE was good, but its predictive value was weaker than that in the miscellaneous CKD cohort originally reported (c-statistics, 0.78 vs. 0.90) and was not significantly improved by adding the D-score (0.78 vs. 0.79, p = 0.83). Only continuous NRI was positive after adding the D-score to the KFRE (0.4%; CI: 0.0-0.8%).

CONCLUSIONS

We found that the predict values of the KFRE and the D-score were not as good as reported, and combining the D-score with the KFRE did not significantly improve prediction of the risk of ESRD in advanced diabetic nephropathy. To improve prediction of renal prognosis for advanced diabetic nephropathy may require different approaches with combining clinical and pathological parameters that were not measured in the KFRE and the RPS DN Classification.

Renal biopsy in patients with diabetes: a pooled meta-analysis of 48 studies

Background

The utility of renal biopsy in patients with diabetes is highly debated. Diabetics with rapidly worsening renal disease are often 'clinically' labelled as having diabetic nephropathy (DN), whereas, in many cases, they are rather developing a non-diabetic renal disease (NDRD) or mixed forms (DN + NDRD).

Methods

We performed a systematic search for studies on patients with diabetes with data on the frequency of DN, NDRD and mixed forms, and assessed the positive predictive values (PPVs) and odds ratios (ORs) for such diagnoses by meta-analysing single-study prevalence. Possible factors explaining heterogeneity among the different diagnoses were explored by meta-regression.

Results

In the 48 included studies ( n = 4876), the prevalence of DN, NDRD and mixed forms ranged from 6.5 to 94%, 3 to 82.9% and 4 to 45.5% of the overall diagnoses, respectively. IgA nephropathy was the most common NDRD (3-59%). PPVs for DN, NDRD and mixed forms were 50.1% [95% confidence interval (CI): 44.7-55.2], 36.9% (95% CI: 32.3-41.8) and 19.7% (95% CI: 16.3-23.6), respectively. The PPV when combining NDRD and mixed forms was 49.2% (95% CI: 43.8-54.5). Meta-regression identified systolic pressure, HbA1c, diabetes duration and retinopathy as factors explaining heterogeneity for NDRD, creatinine and glomerular filtration rate for mixed forms and only serum creatinine for DN. ORs of DN versus NDRD and mixed forms were 1.71 (95% CI: 1.54-1.91) and 4.1 (95% CI: 3.43-4.80), respectively.

Conclusions

NDRD are highly prevalent in patients with diabetes. Clinical judgment alone can lead to wrong diagnoses and delay the establishment of adequate therapies. Risk stratification according to individual factors is needed for selecting patients who might benefit from biopsy.

Clinical and pathological characteristics of non-diabetic renal disease in type 2 diabetes patients

Background

Renal involvement in type 2 diabetes is mainly due to diabetic nephropathy (DN). Nevertheless, a sizable proportion of diabetic patients could actually have nondiabetic renal diseases (NDRDs) or DN plus NDRDs. This study aimed to explore the pathological features of NDRD in diabetic patients and to assess the predictability of diagnosing NDRD (±DN) versus isolated DN on the basis of clinical parameters.

Methods

Medical records of type 2 diabetes patients who underwent renal biopsy under suspicion of NDRD from January 2011 through November 2015 were analyzed retrospectively.

Results

A total of 101 patients were enrolled in this study. The most frequent indication for renal biopsy was recent onset of nephrotic syndrome (41%), followed by rapidly progressive renal failure (29%) and active urinary sediment (21%). On renal biopsy, 51% of patients had isolated DN, 20% had isolated NDRD and 29% had DN plus NDRD. IgA nephropathy was the most common cause of isolated NDRD, whereas acute tubular necrosis (39%) and acute interstitial nephritis (33%) were the main causes of NDRD superimposed on DN. Male gender, short-duration diabetes (<8 years), lower glycated hemoglobin and active urinary sediment (≥10 red and white blood cells per high-power field) were independent predictors of NDRD according to multiple logistic regression analysis.

Conclusions

Judicious use of renal biopsy revealed NDRD (±DN) in nearly half of type 2 diabetes patients with atypical renal presentation, especially in male patients with well-controlled diabetes, those who have had diabetes for a short duration and those with active urinary sediment.

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.

Diabetic Retinopathy and Clinical Parameters Favoring the Presence of Diabetic Nephropathy could Predict Renal Outcome in Patients with Diabetic Kidney Disease

Diabetes duration, diabetic retinopathy (DR), and a diagnostic model have been proposed as clinical parameters favoring the presence of diabetic nephropathy (DN) in biopsied patients with diabetic kidney disease. DN, compared with non-diabetic renal disease, had poorer renal outcomes. We tested whether these clinical parameters favoring DN are associated with poorer renal outcomes in non-biopsied patients. In this study, 1330 patients with type 2 diabetes and chronic kidney disease stages 1-4 were included and divided according to diabetes mellitus (DM) duration >8 years, DR, or a diagnostic model for DN. These clinical parameters favoring DN were found in 62-77% of patients and associated with higher levels of proteinuria. In a Cox survival analysis, DR and the diagnostic model favoring DN were associated with an increased risk for end-stage renal disease with adjusted hazard ratios of 1.69 (95% CI: 1.16-2.45, P = 0.006) and 1.66 (95% CI: 1.05-2.61, P = 0.029), respectively. DR was associated with an increased risk for rapid renal disease progression. DM >8 years was not associated with renal outcome. Propensity score-matched analyses also showed similar results. In conclusion, DR and the diagnostic model favoring DN were associated with poorer renal outcomes.

The large spectrum of renal disease in diabetic patients

The prevalence of diabetic nephropathy (DN) among diabetic patients seems to be overestimated. Recent studies with renal biopsies show that the incidence of non-diabetic nephropathy (NDN) among diabetic patients is higher than expected. Renal impairment of diabetic patients is frequently attributed to DN without meeting the KDOQI criteria or performing renal biopsy to exclude NDN. In this editorial, we update the spectrum of renal disease in diabetic patients and the impact on diagnosis, prognosis and therapy.

Renal pathological implications in type 2 diabetes mellitus patients with renal involvement

AIMS

To investigate the renal pathological implications in type 2 diabetes mellitus patients with renal involvement.

METHODS

A total of 328 type 2 diabetes mellitus (T2DM) patients with renal involvement who underwent a renal biopsy and received follow-up for at least one year were recruited in our study. The patients were divided into the diabetic nephropathy (DN), non-diabetic renal disease (NDRD), and NDRD superimposed on DN groups based on the pathological diagnosis. Renal outcomes were defined by the initiation of renal replacement therapy or doubling of the serum creatinine. Kaplan-Meier analysis was used to compare renal survival, and Cox proportional hazard analysis was used to determine the predictors of renal outcomes in the DN group.

RESULTS

Renal biopsy findings revealed that 188 patients (57.32%) had pure DN, 121 patients (36.89%) had NDRD alone, and 19 patients (5.79%) had NDRD superimposed on DN. The most frequent subclassification of NDRD was membranous nephropathy (MN). Compared with the NDRD and NDRD superimposed on DN groups, patients with pure DN had poorer renal function and lower renal survival rates. In the DN group, the five-year renal survival rates of glomerular classes of I, IIa, IIb, III and IV were 100%, 84.62%, 60%, 47.5% and 33.33%, respectively. Multivariate Cox proportional hazard analysis showed that the glomerular lesions, proteinuria and serum creatinine were independent risk factors for renal outcomes, while interstitial fibrosis/inflammation and arteriolar hyalinosis were not independently associated with renal outcomes in the DN group.

CONCLUSIONS

Making an accurate pathologic diagnosis by renal biopsy is crucial for diabetes mellitus (DM) patients with renal involvement. The findings of our present study indicated that patients with pure DN had poorer renal outcomes than patients with NDRD or NDRD superimposed on DN. The classification of glomerular lesions, proteinuria and serum creatinine were independent risk factors for renal outcomes in the DN group. More studies with large samples and longer time follow-up are needed to evaluate the relationship between pathological changes and clinical characteristics in T2DM patients who have renal involvement.

Classification and Differential Diagnosis of Diabetic Nephropathy

Diabetic nephropathy (DN) is a major cause of end-stage renal disease throughout the world in both developed and developing countries. This review briefly introduces the characteristic pathological changes of DN and Tervaert pathological classification, which divides DN into four classifications according to glomerular lesions, along with a separate scoring system for tubular, interstitial, and vascular lesions. Given the heterogeneity of the renal lesions and the complex mechanism underlying diabetic nephropathy, Tervaert classification has both significance and controversies in the guidance of diagnosis and prognosis. Applications and evaluations using Tervaert classification and indications for renal biopsy are summarized in this review according to recent studies. Meanwhile, differential diagnosis with another nodular glomerulopathy and the situation that a typical DN superimposed with a nondiabetic renal disease (NDRD) are discussed and concluded in this review.

Presentation, pathology and prognosis of renal disease in type 2 diabetes

OBJECTIVE

Non-diabetic renal disease (NDRD) is common in patients with type 2 diabetes (T2D), but the relationship between its presentation and prognosis is unknown.

RESEARCH DESIGN AND METHODS

In a retrospective cohort study, we compared renal and patient survival among 263 patients with T2D who had native renal biopsies between 2002 and 2008 from three Auckland hospitals in New Zealand. The presence of diabetic nephropathy (DN), NDRD or mixed (DN and NDRD) was determined from biopsy. We examined clinical associations according to NDRD etiologies and mode of presentation-acute (defined by acute kidney injury (AKI)) or non-acute. Patients were followed until end-stage renal disease, death or December 2015. Survival was compared using Log-rank test.

RESULTS

94 (36%) patients had DN, 72 (27%) had NDRD, and 97 (37%) had mixed pathologies. Obesity-related focal segmental glomerulosclerosis was the most common NDRD (46%) in patients with non-acute presentations, whereas interstitial nephritis or immune-complex glomerulonephritides were the most prevalent in those with acute presentations (60%). DN was commonly associated with AKI (p<0.001). The prevalence of DN increased with diabetes duration (p<0.001), but NDRD was still found in 55% of subjects with ≥14 years T2D. NDRD was strongly associated with the absence of retinopathy (p<0.001). Renal survival was best in the NDRD group (p<0.001). Among those with DN, renal prognosis was worse in those with more advanced DN lesions and those with an acute presentation (p<0.001). The proportion of all-cause mortality was similar in all three groups, but overall survival was poorest in the DN group (p=0.025).

CONCLUSIONS

Renal disease in patients with T2D is heterogeneous. The renal prognosis differs markedly according to histopathological diagnosis and mode of presentation.

Clinical predictors differentiating non-diabetic renal diseases from diabetic nephropathy in a large population of type 2 diabetes patients

AIMS

Non-diabetic renal diseases (NDRDs) are associated with better renal outcomes than diabetic nephropathy (DN). This study was conducted to determine the common clinical markers predicting NDRDs in type 2 diabetes patients.

METHODS

Patients with type 2 diabetes mellitus who underwent a renal biopsy were screened. Eligible patients were categorized into two groups: DN group and NDRD group. Patient's clinical characteristics and laboratory data were collected. Logistic regression analysis was performed to identify risk factors for NDRD development, and the diagnostic performance of these variables was evaluated.

RESULTS

The study included 248 patients, 96 (38.71%) in the DN group and 152 (61.29%) in the NDRD group. Patients in the NDRD group had a shorter duration of DM and higher hemoglobin, estimated glomerular filtration rate, and urine osmotic pressure values as well as a higher incidence of glomerular hematuria than patients in the DN group. In the NDRD patients, the most common pathological type was membranous nephropathy (55, 36.18%). Absence of retinopathy (OR, 44.696, 95% CI, 15.91-125.566), glomerular hematuria (OR, 9.587, 95% CI, 2.027-45.333), and DM history ⩽5years (OR, 4.636, 95% CI, 1.721-12.486) were significant and independent risk factors for the development of NDRD (P<0.01). Absence of retinopathy achieved the overall highest diagnostic efficiency with a sensitivity of 92.11% and specificity of 82.29%. Glomerular hematuria had the highest specificity (93.75%).

CONCLUSION

Shorter duration of diabetes (⩽5years), absence of retinopathy, and presence of glomerular hematuria were independent indicators associated with NDRDs, indicating the need for renal biopsy.

Low-Protein Diets in Diabetic Chronic Kidney Disease (CKD) Patients: Are They Feasible and Worth the Effort?

Low-protein diets (LPDs) are often considered as contraindicated in diabetic patients, and are seldom studied. The aim of this observational study was to provide new data on this issue. It involved 149 diabetic and 300 non-diabetic patients who followed a LPD, with a personalized approach aimed at moderate protein restriction (0.6 g/day). Survival analysis was performed according to Kaplan-Meier, and multivariate analysis with Cox model. Diabetic versus non-diabetic patients were of similar age (median 70 years) and creatinine levels at the start of the diet (2.78 mg/dL vs. 2.80 mg/dL). There was higher prevalence of nephrotic proteinuria in diabetic patients (27.52% vs. 13.67%, p = 0.002) as well as comorbidity (median Charlson index 8 vs. 6 p = 0.002). Patient survival was lower in diabetic patients, but differences levelled off considering only cases with Charlson index > 7, the only relevant covariate in Cox analysis. Dialysis-free survival was superimposable in the setting of good compliance (Mitch formula: 0.47 g/kg/day in both groups): about 50% of the cases remained dialysis-free 2 years after the first finding of e-GFR (estimated glomerular filtration rate) < 15 mL/min, and 1 year after reaching e-GFR < 10 mL/min. In patients with type 2 diabetes, higher proteinuria was associated with mortality and initiation of dialysis. In conclusion, moderately restricted LPDs allow similar results in diabetic and non non-diabetic patients with similar comorbidity.

Predictive factors for non-diabetic nephropathy in diabetic patients. The utility of renal biopsy

BACKGROUND AND OBJECTIVES

Diabetic renal lesions can only be diagnosed by kidney biopsy. These biopsies have a high prevalence of non-diabetic lesions. The aims of the study were to determine the predictability of non-diabetic nephropathy (NDN) in diabetics and study differences in survival and renal prognosis. In addition, we evaluated histological lesions and the effect of proteinuria on survival and renal prognosis in patients with diabetic nephropathy (DN).

MATERIAL AND METHODS

A descriptive, retrospective study of kidney biopsies of diabetics between 1990 and 2013 in our centre.

RESULTS

110 patients were included in the study: 87 men (79%), mean age 62 years (50-74), mean serum creatinine 2.6mg/dl (0.9-4.3) and proteinuria 3.5g/24hours (0.5-6.5). 61.8% showed NDN, 34.5% showed DN and 3,6% showed DN+NDN. The most common NDN was IgA nephropathy (13,2%). In the multivariate analysis, creatinine (OR: 1.48, 1.011-2.172, p=0.044), proteinuria/24hours (OR: 0.813, 0.679-0.974, p=0.025), duration of diabetes (OR: 0.992, 0.987-0.998, p=0.004), age (OR: 1.068, 95% CI: 1.010-1.129, p=0.022), and diabetic retinopathy (OR: 0.23, 0.066-0.808, p=0.022) were independently associated with NDN. We did not find any differences in survival or renal prognosis. Concerning patients with DN, increased nodular mesangial expansion (p=0.02) and worse renal prognosis (p=0.004) were observed in nephrotic proteinuria as compared to non-nephrotic proteinuria. We did not find differences in patient survival.

CONCLUSIONS

The most common cause of NDN was IgA nephropathy. Higher creatinine levels, shorter duration of diabetes, absence of diabetic retinopathy, lower proteinuria, and older age were risk factors for NDN. Patients with DN and nephrotic-range proteinuria had worse renal prognosis.