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

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.

Serum soluble urokinase plasminogen activator receptor as a potential biomarker of renal impairment severity in diabetic nephropathy

AIMS

To investigate serum soluble form of urokinase-type plasminogen activator receptor (suPAR) in patients with diabetic kidney disease (DKD) and biopsy-proven diabetic nephropathy (DN), its correlation with histological parameters and its capacity as a biomarker for renal impairment severity.

METHODS

We conducted a cross-sectional study on 75 patients with diabetes mellitus (DM) and DKD, among whom 28 had biopsy-proven DN.

RESULTS

Among the 75 patients, 9 (12%) had type 1 and 66 (88%) type 2 DM. The median value of the serum suPAR level was 2857.2 pg/mL (1916.4-3700) in the entire cohort and 2472.1 pg/mL (1782.6-3745.8) in the biopsy-proven DN subgroup, respectively. suPAR was significantly correlated with diabetes duration, diabetic retinopathy, anti-proteinuric treatment, albuminuria, kidney function, DN class, interstitial fibrosis and tubular atrophy (IFTA) score and with interstitial inflammation score. suPAR had a good accuracy for the association with chronic kidney disease (CKD) stages G3b-5, macroalbuminuria, DN class IV, IFTA score 3 and interstitial inflammation score 2.

CONCLUSIONS

Serum suPAR was increased in DN patients and was associated with DM duration, diabetic retinopathy, renoprotective treatment, kidney function, proteinuria, DN class, IFTA and interstitial inflammation scores. Also, suPAR had a good capacity as a biomarker for advanced renal impairment and severe histological lesions of DN.

How to Assess Diabetic Kidney Disease Progression? From Albuminuria to GFR

Diabetic kidney disease (DKD) is one of the most relevant complications of type 2 diabetes and dramatically increases the cardiovascular risk in these patients. Currently, DKD is severely infra-diagnosed, or its diagnosis is usually made at advanced stages of the disease. During the last decade, new drugs have demonstrated a beneficial effect in terms of cardiovascular and renal protection in type 2 diabetes, supporting the crucial role of an early DKD diagnosis to permit the use of new available therapeutic strategies. Moreover, cardiovascular and renal outcome trials, developed to study these new drugs, are based on diverse cardiovascular and renal simple and composite endpoints, which makes difficult their interpretation and the comparison between them. In this article, DKD diagnosis is reviewed, focusing on albuminuria and the recommendations for glomerular filtration rate measurement. Furthermore, cardiovascular and renal endpoints used in classical and recent cardiovascular outcome trials are assessed in a pragmatic way.

Role of non-alcoholic fatty liver disease in the evolution of renal function in patients with diabetes mellitus

BACKGROUND

Increasing prevalence in type 2 diabetes mellitus (T2DM) have influenced in an increasing prevalence of chronic kidney disease (CKD). Little is known about the influence of non-alcoholic fatty liver disease (NAFLD) on progression of CKD. The aim of this study was to analyse the role of NAFLD and its severity in the progression of renal function in patients with T2DM.

METHODS

Retrospective and observational study, including patients with T2DM and estimated glomerular filtration rate (eGFR) >30 ml/min/1,73m2. NAFLD was defined with presence of compatible ultrasonography and/or presence of fibrosis using NAFLD score. Patients were classified in three groups according to the NAFLD score; group 1 <-1.85, group 2 -1.85 to 0.18, and group 3 > 0.18.

RESULTS

A total of 102 patients were included (67.6% males, median age 59 [53-64] years), with median time of T2DM evolution was 70 [39-131] months. Group 3 had lower eGFR (84.8  ±  40.4 vs 71.4  ±  30.6 ml/min/1.73m2; p = 0.03) and higher proteinuria at baseline (0.56  ±  0.77 vs 1.59  ±  2.70 g/24h; p = 0.05). After a follow-up time of 75.8  ±  23.9 months, group 3 had a significant decrease in eGFR (66.6  ±  33.3 vs 36.8  ±  23.1 ml/min/1.73m2; p = <0.01), and higher risk of CKD progression (OR 7.50; CI 95% 2.76-20.35; p = <0.001) defined as decrease in > 50% eGFR.

CONCLUSIONS

The presence of NAFLD with high-risk fibrosis confers higher risk of CKD progression in patients with T2DM. Therefore, NAFLD should be a risk factor evaluated in these patients to optimise treatment.