Proteinuria in Diabetic Patients – Is It Always Diabetic Nephropathy?

Evaluation of salivary glycopatterns based diagnostic models for prediction of diabetic vascular complications

Diabetic vascular complications (DVC) are the main cause of death in diabetic patients. However, there is a lack of effective biomarkers or convenient methods for early diagnosis of DVC. In this study, the salivary glycopatterns from 130 of healthy volunteers (HV), 139 patients with type 2 diabetes mellitus (T2DM) and 167 patients with DVC were case-by-case analyzed by using lectin microarrays. Subsequently, diagnostic models were developed using logistic regression and machine learning algorithms based on the data of lectin microarrays in training set. The performance of diagnostic models was evaluated in an independent blind cohort. The results of lectin microarrays indicated that the glycopatterns identified by 16 lectins (e.g. BS-I, PWM and EEL) were significantly altered in DVC patients compared with patients with T2DM, which suggested the alterations in salivary glycopatterns could reflect onset of DVC. Notably, K-Nearest Neighbor (KNN) model exhibited better performance for distinguishing DVC (accuracy: 0.939) than other models in blind cohort. The integrated classifier, which combined three machine learning models, exhibited a higher overall accuracy (≥ 0.933) than other models in blind cohort. Our study provided a cost-effective and non-invasive method for auxiliary diagnosis DVC based on the combination of salivary glycopatterns and machine learning algorithms.

The modern spectrum of biopsy-proven renal disease in Chinese diabetic patients-a retrospective descriptive study

Background

Renal biopsies performed in diabetic patients are increasing and becoming more complex. Comprehensive data on modern spectrum of biopsy-proven renal disease in Chinese diabetic patients are lacking.

Methods

In a nationwide renal biopsy survey including 71,151 native biopsies from 2004 to 2014, diabetic patients were identified according to the clinical diagnosis from referral records. The clinical data were extracted from referral records and pathological reports.

Results

A total of 1,604 diabetic patients, including 61 patients with T1DM, were analyzed in this study. The median age is 51.39 ± 11.37 years. Male patients accounted for 58% of the population. We found that only 44.7% of diabetic patients had the isolated pathological diagnosis of diabetic nephropathy (DN), while 49.1% had non-diabetic renal disease (NDRD) alone, and 6.2% had NDRD superimposed on DN. Nephrotic syndrome (n = 824, 51.4%) was the most common clinical indication for renal biopsy. Among 887 patients with NDRD, membranous nephropathy (n = 357) was the leading diagnosis, followed by IgA nephropathy (n = 179). Hypertensive renal disease (n = 32), tubulointerstitial nephropathy (n = 27) and acute tubular necrosis (n = 16) accounted for 3.5%, 2.9%, 1.7% of the NDRD cases respectively. Nearly a half (49.2%) of patients with T1DM had NDRD.

Discussion

Over 55% diabetic patients with kidney disease were diagnosed as non-diabetic renal disease, among which MN and IgAN were the most common two pathological types.

Spectrum of renal disease in diabetes

The spectrum of renal disease in patients with diabetes encompasses both diabetic kidney disease (including albuminuric and non-albuminuric phenotypes) and non-diabetic kidney disease. Diabetic kidney disease can manifest as varying degrees of renal insufficiency and albuminuria, with heterogeneity in histology reported on renal biopsy. For patients with diabetes and proteinuria, the finding of non-diabetic kidney disease alone or superimposed on the changes of diabetic nephropathy is increasingly reported. It is important to identify non-diabetic kidney disease as some forms are treatable, sometimes leading to remission. Clinical indications for a heightened suspicion of non-diabetic kidney disease and hence consideration for renal biopsy in patients with diabetes and nephropathy include absence of diabetic retinopathy, short duration of diabetes, atypical chronology, presence of haematuria or other systemic disease, and the nephrotic syndrome.

Clinical versus histological diagnosis of diabetic nephropathy--is renal biopsy required in type 2 diabetic patients with renal disease?

OBJECIVES

The clinical and histological diagnosis (gold standard) of diabetic nephropathy (dNP) and vascular nephropathy (vNP) were compared in type 2 diabetic patients with end-stage renal disease (ESRD).

AIM

The aim of the study was to investigate indication for renal biopsy in type 2 diabetic patients with renal disease.

DESIGN

Retrospective study in diabetic patients with clinical and histological diagnosis of renal disease.

PATIENTS AND METHODS

Eighty-four patients with type 2 diabetes and ESRD were investigated. Histological findings of the kidneys were available in all patients, 14 had undergone a renal biopsy before their first dialysis while a post-mortem kidney investigation was performed in 70 subjects. According to the histological findings, 66 patients had dNP and 18 subjects had vNP. The histological diagnosis was compared with the clinical diagnosis, and the sensitivity as well as the specificity of the clinical diagnosis of dNP and vNP were calculated.

RESULTS

The clinical diagnosis was not identical with the histological diagnosis in 10 cases. In the dNP group the diagnosis was 4 false positive and 3 false negative as in the vNP group 1 false positive and 2 false negative. The sensitivity of clinical diagnosis was 95% for dNP and 89% for vNP. Specificity was 78% for dNP and 97% for vNP.

CONCLUSION

The sensitivity of the clinical diagnosis is very high for dNP as well as vNP. A renal biopsy is not required in the majority of type 2 diabetic patients with ESRD, especially in patients who exhibit all criteria for clinical diagnosis.

Factors associated with diabetic nephropathy in subjects with proliferative retinopathy

AIM

The purpose was to compare the phenotype of subjects with type 2 diabetes mellitus having both retinopathy and nephropathy with that of subjects having retinopathy but no nephropathy.

METHODS

We recruited 196 subjects; 85 were normoalbuminuric (controls), whilst cases consisted of patients with micro- (n = 66) or macroalbuminuria (n = 45). Both groups underwent 24-h blood pressure (BP) monitoring and were analysed regarding markers of the metabolic syndrome, inflammation (erythrocyte sedimentation rate [ESR] and high-sensitivity CRP [hsCRP]) and insulin resistance (HOMA-IR).

RESULTS

Cases had significantly higher white cell count (P = 0.02), ESR (P < 0.001), platelets (P = 0.02), triglycerides (P = 0.001), uric acid (P < 0.001), daytime and night-time systolic BP (P = 0.001 & P = 0.001, respectively), diastolic BP (P = 0.007 & P = 0.001), pulse pressure (P = 0.02 & 0.055) and mean arterial pressure (P = 0.001 & P < 0.001) in univariate analysis. Cases had a lower haemoglobin level (P = 0.01) and estimated glomerular filtration rate (eGFR) (P = 0.002) in comparison with controls. Multivariate analysis showed that night-time diastolic BP (P = 0.002, B = 1.057), platelet count (P = 0.018, B = 1.007) and eGFR (P < 0.001, B = 0.097) are independent predictors of diabetic nephropathy. Platelet count (P = 0.045, B = 1.006), night-time mean diastolic BP (P = 0.029, B = 1.042) and eGFR (P = 0.001, B = 0.975) were also found to be independent predictors of the occurrence of microalbuminuria.

CONCLUSIONS

By analysing factors associated with diabetic nephropathy rather than microvascular disease in general, this study provides evidence that night-time diastolic BP and a relative increase in platelet count are associated with incipient diabetic nephropathy.

Serum lipid profile in diabetic macular edema

PURPOSE

To evaluate the correlation of lipid profile and clinical presentation of macular edema in Type 2 diabetes mellitus (DM) patients.

MATERIALS AND METHODS

The study included 20 patients with chronic diabetic macular edema and plaque-like hard exudates (Group 1), 20 patients with diabetic macular edema (Group 2), and 20 DM patients but without retinopathy (Group 3). Diabetic retinopathy was classified according to the Early Treatment Diabetic Retinopathy Study grading system. Sample t test was used to evaluate the association between the fasting serum lipid [total cholesterol, triglyceride, low-density lipoprotein (LDL), high-density lipoprotein (HDL)], glycosylated hemoglobin (HbA1c), fasting blood glucose, creatinine levels, and the clinical findings. P values <.05 were considered statistically significant.

RESULTS

There was no difference between fasting serum lipids and HbA1c levels. Duration of diabetes was shorter in Group 3 than in Groups 1 and 2. Patients in Group 1 had longer duration of diabetes than others (P<.05). Creatinine levels in Group 1 were higher than in other groups (P<.05). Although there was no correlation between fasting blood glucose and HbA1c levels, HbA1c was higher in all three groups from the baseline-normal limits (P<.05).

CONCLUSION

No correlation was found between serum lipid levels and macular edema severity, but the duration of diabetes was demonstrated as a significant factor in the progression of macular edema. High HbA1c levels in all patients highlight the importance of intense glycemic control in diabetic patients.

Interactions between microvascular and macrovascular disease in diabetes: pathophysiology and therapeutic implications

Convention partitions the complications of diabetes into two main subtypes. First are the diabetes-specific microvascular complications of retinopathy, nephropathy and neuropathy; second are the atherothrombotic macrovascular complications that account for the majority of premature deaths. Pathological interactions between microvascular and macrovascular complications, for example, nephropathy and macrovascular disease, are common. Similar mechanisms and shared risk factors drive the development and progression of both small and large vessel disease. This concept has therapeutic implications. Mounting evidence points to the need for multifactorial strategies to prevent vascular complications in subjects with diabetes and/or the metabolic syndrome. We advocate a combined therapeutic approach that addresses small and large vessel disease. Preferential use should be made of drug regimens that (i) maximize vascular protection, (ii) reduce the risk of iatrogenic vascular damage and (iii) minimize the increasing problem of polypharmacy.