Retinol-binding protein 4 versus albuminuria as predictors of estimated glomerular filtration rate decline in patients with type 2 diabetes

Adipokines and their role in acute pancreatitis

Acute pancreatitis (AP) is characterized by an inflammatory response that leads to edema and haemorrhaging of pancreatic tissue. In severe cases, it can even result in the necrosis of pancreatic tissue following activation within the pancreas. Adipokines are biologically active molecules released by adipose tissue that have a wide-ranging impact on health and disease. Adipokines are cytokines produced not only in white adipose tissue but also in the fat surrounding the pancreas, and they play a role in the body's inflammatory response. The presence of increased adipose tissue, often associated with obesity, has been linked to a heightened systemic inflammatory response in cases of AP. According to the literature, there are many adipokines. This article summarizes the role of adipokines in AP. Adipokines could be promising biomarkers for both diagnostic and new therapeutic treatment strategies in AP. However, a deeper knowledge of the signaling pathways of adipokines and their potential therapeutic role in AP is necessary.

Urinary orosomucoid and retinol binding protein levels as early diagnostic markers for diabetic kidney Disease

BACKGROUND

Diabetic kidney disease (DKD) is the most common microvascular complication of diabetes, which has been a major cause of end-stage renal failure. Diagnosing diabetic kidney disease is important to prevent long-term kidney damage and determine the prognosis of patients with diabetes. In this study, we investigated the clinical significance of combined detection of urine orosomucoid and retinol-binding protein for early diagnosis of diabetic kidney disease.

METHODS

We recruited 72 newly diagnosed patients with type 2 diabetes and 34 healthy persons from August 2016 to July 2018 at the First Affiliated Hospital of Henan Polytechnic University (Jiaozuo Second People's Hospital). Using the Mogensen grading criteria, participants were classified as having diabetes or diabetic kidney disease, and healthy persons constituted the control group. Urine orosomucoid and retinol-binding protein levels were measured and correlated with other variables.

RESULTS

With the aggravation of renal damage, the level of urinary mucoid protein gradually increased. Urinary retinol-binding protein and microalbumin levels were significantly higher in the diabetes group than in control and nephropathy groups. Orosomucoid and retinol-binding protein might be independent risk factors for diabetes and diabetic kidney disease. Urinary orosomucoid significantly correlated with retinol-binding protein and microalbumin levels in the diabetic kidney disease group.

CONCLUSION

Elevated urine orosomucoid and retinol-binding protein levels can be detected in the early stages of type 2 diabetic kidney disease. Both of these markers are important for diabetic kidney disease detection and early treatment.

Micro-ribonucleic acid modulation with oxidative stress and inflammation in patients with type 2 diabetes mellitus - a review article

In parallel with the rapid growth of obesity, there is also an increase in the prevalence of type 2 diabetes mellitus (T2D) worldwide. Due to its complications, cardiovascular diseases are the leading cause of death in those patients. In the last two decades, special attention has been given to oxidative stress and inflammation, as the underlying mechanisms related to T2D occurrence and progression. Moreover, micro-ribonucleic acids (miRNAs) as new genetic biomarkers take an important place in the investigation of different metabolic pathways of insulin signaling. In this review article, we discuss microRNA modulation with oxidative stress and inflammation in patients with T2D. Better insight into the novel potential therapeutic targets for treatment of diabetes and its complications is of utmost importance for public health.

Association of serum uromodulin with adipokines in dependence of type 2 diabetes

BACKGROUND

The renal tubular glycoprotein uromodulin is associated with obesity and type 2 diabetes, but the underlying mechanisms are elusive. We investigated the association of serum uromodulin with adipokines and tested the effect modification by diabetes status.

METHODS

The associations of serum uromodulin with eight adipokines were assessed in 795-1080 participants of the KORA F4 study aged 62-81 years using linear regression models adjusted for sex, age, BMI, estimated glomerular filtration rate and diabetes. Significant associations were assessed for effect modification by diabetes status. We further tested using logistic regression whether adjustment for the significant adipokines affected the association of uromodulin with type 2 diabetes.

RESULTS

Serum uromodulin was inversely associated with chemerin and retinol-binding protein-4 after multivariable adjustment (p < 0.001) and Bonferroni correction for multiple testing. No significant association was observed between uromodulin and the other adipokines (leptin, adiponectin, secreted frizzled-related protein 5, progranulin, omentin-1 and vaspin) after correcting for multiple testing. The association of uromodulin with chemerin and retinol-binding protein-4 was stronger in participants with type 2 diabetes than in participants without diabetes (p for interaction < 0.05). However, inclusion of chemerin and retinol-binding protein-4 in logistic regression models did not attenuate the association of serum uromodulin with diabetes.

CONCLUSIONS

Serum uromodulin was inversely associated with the predominantly pro-inflammatory adipokines chemerin and retinol-binding protein-4. The associations were stronger in participants with type 2 diabetes compared to participants without diabetes. However, the association of serum uromodulin with type 2 diabetes was independent of chemerin and retinol-binding protein-4.

Prognostic models of diabetic microvascular complications: a systematic review and meta-analysis

BACKGROUND

Many prognostic models of diabetic microvascular complications have been developed, but their performances still varies. Therefore, we conducted a systematic review and meta-analysis to summarise the performances of the existing models.

METHODS

Prognostic models of diabetic microvascular complications were retrieved from PubMed and Scopus up to 31 December 2020. Studies were selected, if they developed or internally/externally validated models of any microvascular complication in type 2 diabetes (T2D).

RESULTS

In total, 71 studies were eligible, of which 32, 30 and 18 studies initially developed prognostic model for diabetic retinopathy (DR), chronic kidney disease (CKD) and end stage renal disease (ESRD) with the number of derived equations of 84, 96 and 51, respectively. Most models were derived-phases, some were internal and external validations. Common predictors were age, sex, HbA1c, diabetic duration, SBP and BMI. Traditional statistical models (i.e. Cox and logit regression) were mostly applied, otherwise machine learning. In cohorts, the discriminative performance in derived-logit was pooled with C statistics of 0.82 (0.73‑0.92) for DR and 0.78 (0.74‑0.83) for CKD. Pooled Cox regression yielded 0.75 (0.74‑0.77), 0.78 (0.74‑0.82) and 0.87 (0.84‑0.89) for DR, CKD and ESRD, respectively. External validation performances were sufficiently pooled with 0.81 (0.78‑0.83), 0.75 (0.67‑0.84) and 0.87 (0.85‑0.88) for DR, CKD and ESRD, respectively.

CONCLUSIONS

Several prognostic models were developed, but less were externally validated. A few studies derived the models by using appropriate methods and were satisfactory reported. More external validations and impact analyses are required before applying these models in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018105287.

Transcriptome Analysis of Kidney Grafts Subjected to Normothermic Ex Vivo Perfusion Demonstrates an Enrichment of Mitochondrial Metabolism Genes

Normothermic ex vivo kidney perfusion (NEVKP) has demonstrated superior outcomes for donation-after-cardiovascular death grafts compared with static cold storage (SCS). To determine the mechanisms responsible for this, we performed an unbiased genome-wide microarray analysis.

METHODS

Kidneys from 30-kg Yorkshire pigs were subjected to 30 min of warm ischemia followed by 8 h of NEVKP or SCS, or no storage, before autotransplantation. mRNA expression was analyzed on renal biopsies on postoperative day 3. Gene set enrichment analysis was performed using hallmark gene sets, Gene Ontology, and pathway analysis.

RESULTS

The gene expression profile of NEVKP-stored grafts closely resembled no storage kidneys. Gene set enrichment analysis demonstrated enrichment of fatty acid metabolism and oxidative phosphorylation following NEVKP, whereas SCS-enriched gene sets were related to mitosis, cell cycle checkpoint, and reactive oxygen species (q < 0.05). Pathway analysis demonstrated enrichment of lipid oxidation/metabolism, the Krebs cycle, and pyruvate metabolism in NEVKP compared with SCS (q < 0.05). Comparison of our findings with external data sets of renal ischemia-reperfusion injury revealed that SCS-stored grafts demonstrated similar gene expression profiles to ischemia-reperfusion injury, whereas the profile of NEVKP-stored grafts resembled recovered kidneys.

CONCLUSIONS

Increased transcripts of key mitochondrial metabolic pathways following NEVKP storage may account for improved donation-after-cardiovascular death graft function, compared with SCS, which promoted expression of genes typically perturbed during IRI.

Diabetic kidney disease: new clinical and therapeutic issues. Joint position statement of the Italian Diabetes Society and the Italian Society of Nephrology on "The natural history of diabetic kidney disease and treatment of hyperglycemia in patients with type 2 diabetes and impaired renal function"

Aims

This joint document of the Italian Diabetes Society and the Italian Society of Nephrology reviews the natural history of diabetic kidney disease (DKD) in the light of the recent epidemiological literature and provides updated recommendations on anti-hyperglycemic treatment with non-insulin agents.

Data Synthesis

Recent epidemiological studies have disclosed a wide heterogeneity of DKD. In addition to the classical albuminuric phenotype, two new albuminuria-independent phenotypes have emerged, i.e., “nonalbuminuric renal impairment” and “progressive renal decline”, suggesting that DKD progression toward end-stage kidney disease (ESKD) may occur through two distinct pathways, albuminuric and nonalbuminuric. Several biomarkers have been associated with decline of estimated glomerular filtration rate (eGFR) independent of albuminuria and other clinical variables, thus possibly improving ESKD prediction. However, the pathogenesis and anatomical correlates of these phenotypes are still unclear. Also the management of hyperglycemia in patients with type 2 diabetes and impaired renal function has profoundly changed during the last two decades. New anti-hyperglycemic drugs, which do not cause hypoglycemia and weight gain and, in some cases, seem to provide cardiorenal protection, have become available for treatment of these individuals. In addition, the lowest eGFR safety thresholds for some of the old agents, particularly metformin and insulin secretagogues, have been reconsidered.

Conclusions

The heterogeneity in the clinical presentation and course of DKD has important implications for the diagnosis, prognosis, and possibly treatment of this complication. The therapeutic options for patients with type 2 diabetes and impaired renal function have substantially increased, thus allowing a better management of these individuals.

Vascular peroxidase 1 is independently associated with worse kidney function in patients with peripheral artery disease

BACKGROUND

Oxidative stress is involved in cardiovascular disease such as peripheral artery disease (PAD). Vascular Peroxidase 1 (VPO1), a novel heme-containing peroxidase mainly expressed in the cardiovascular system, aggravates oxidative stress. Evidence in humans is limited. Current work aims to measure VPO1 in patients suffering from PAD, and to evaluate the association of VPO1 with conventional markers of cardiovascular risk factors (CVRF), including the estimated glomerular filtration rate (eGFR) and albuminuria categories.

METHODS

This study is part of a longitudinal observational study. At baseline, 236 PAD-patients were included. VPO1 plasma levels (ng/mL) were measured by commercially available ELISA kits. A two-sided p level of < 0.05 was considered statistically significant.

RESULTS

In the cross-sectional analysis (n = 236), VPO1 associated with ageing (p = 0.035) as well as with eGFR and albuminuria category, the markers of chronic kidney disease (CKD)-progression (p = 0.042). The longitudinal 18-months follow-up analysis (n = 152) demonstrated that baseline VPO1 predicts rapid kidney function decline (RKFD) (n = 49), defined as more than - 3 mL/min/1.73m2 eGFR loss per year, (OR per one SD VPO1 1.60 (1.11-2.30); p = 0.009). This association between VPO1 and kidney function withstood the multivariable adjustment for traditional CVRF including baseline eGFR and urine albumin-to-creatinine ratio (UACR), (adjOR per one SD VPO1 1.73 (1.14-2.61); p = 0.046).

CONCLUSION

This study is first to reveal that VPO1 is independently associated with declining kidney function in patients with PAD. VPO1 shows a tighter association to kidney function than to other CVRF. This finding points to VPO1 as a potential target protein to assess CKD-progression.

The Role of Circulating RBP4 in the Type 2 Diabetes Patients with Kidney Diseases: A Systematic Review and Meta-Analysis

BACKGROUND

Diabetic nephropathy is a common and serious complication of diabetes mellitus (DM) and is one of the leading causes of end-stage renal disease worldwide. Although there have been many investigations on biomarkers for DN, there is no consistent conclusion about reliable biomarkers. The purpose of this study was to perform a systematic review and meta-analysis of the role of circulating retinol-binding protein 4 (RBP4) in the type 2 diabetes mellitus (T2DM) patients with kidney diseases.

MATERIALS AND METHODS

We searched the PubMed, MEDLINE, EMBASE, and Web of Science databases for publications. For the 12 cross-sectional studies that we included in the review, we calculated standard mean differences (SMD) with 95% confidence intervals (CI) for continuous data when the applied scales were different. Risk of bias of included trials was assessed by using the Newcastle-Ottawa Scale.

RESULTS

RBP4 concentrations in the micro-, macro-, or micro+macroalbuminuria groups were significantly higher than those in the normal albuminuria group of T2DM patients [P = 0.001, SMD 1.07, 95% CI (0.41, 1.73)]. The estimated glomerular filtration rate (eGFR) was negatively associated with circulating RBP4 concentrations in patients with T2DM [summary Fisher's Z = -0.48, 95% CI (-0.69, -0.26), P < 0.0001]. The albumin-to-creatinine ratio (ACR) was positively associated with circulating RBP4 concentrations in patients with T2DM [summary Fisher's Z = 0.20, 95% CI (0.08, 0.32), P = 0.001].

CONCLUSION

The levels of circulating RBP4 were significantly higher both in T2DM subjects with micro/macroalbuminuria and in T2DM subjects with declined eGFR. The levels of circulating RBP4 were positively correlated with ACR but negatively correlated with eGFR. Circulating RBP4 could be a reliable biomarker for kidney diseases in T2DM.

Diabetic kidney disease: New clinical and therapeutic issues. Joint position statement of the Italian Diabetes Society and the Italian Society of Nephrology on "The natural history of diabetic kidney disease and treatment of hyperglycemia in patients with type 2 diabetes and impaired renal function"

AIMS

This joint document of the Italian Diabetes Society and the Italian Society of Nephrology reviews the natural history of diabetic kidney disease (DKD) in the light of the recent epidemiological literature and provides updated recommendations on anti-hyperglycemic treatment with non-insulin agents.

DATA SYNTHESIS

Recent epidemiological studies have disclosed a wide heterogeneity of DKD. In addition to the classical albuminuric phenotype, two new albuminuria-independent phenotypes have emerged, i.e., "nonalbuminuric renal impairment" and "progressive renal decline", suggesting that DKD progression toward end-stage kidney disease (ESKD) may occur through two distinct pathways, albuminuric and nonalbuminuric. Several biomarkers have been associated with decline of estimated glomerular filtration rate (eGFR) independent of albuminuria and other clinical variables, thus possibly improving ESKD prediction. However, the pathogenesis and anatomical correlates of these phenotypes are still unclear. Also the management of hyperglycemia in patients with type 2 diabetes and impaired renal function has profoundly changed during the last two decades. New anti-hyperglycemic drugs, which do not cause hypoglycemia and weight gain and, in some cases, seem to provide cardiorenal protection, have become available for treatment of these individuals. In addition, the lowest eGFR safety thresholds for some of the old agents, particularly metformin and insulin secretagogues, have been reconsidered.

CONCLUSIONS

The heterogeneity in the clinical presentation and course of DKD has important implications for the diagnosis, prognosis, and possibly treatment of this complication. The therapeutic options for patients with type 2 diabetes and impaired renal function have substantially increased, thus allowing a better management of these individuals.

The Association of Serum hsCRP and Urinary Alpha1-Microglobulin in Patients with Type 2 Diabetes Mellitus

This study aimed to investigate the association of serum hsCRP and urinary A1MG in patients with T2DM. Numerous investigations have proven that serum hypersensitive C-reactive protein (hsCRP) concentration in patients with type 2 diabetes mellitus (T2DM) is increased. Also, increased urinary alpha-1 microglobulin (A1MG) can be an early sign of renal damage, primarily on the proximal tubules in T2DM. Little information is available with respect to the associations of serum hsCRP levels and urinary A1MG in T2DM. A total of 520 patients with T2DM were recruited to participate in this study. Serum hsCRP and UA1MG (urinary alpha1-microglobulin to creatinine ratio), UACR (urinary microalbumin to creatinine ratio), UIGG (urinary immunoglobulin G to creatinine ratio), and UTRF (urinary transferrin to creatinine ratio) were obtained. The association of serum hsCRP level and each urinary protein parameter was analyzed by using the regression analysis, respectively. LnhsCRP was positively associated with the lnUA1MG in all three linear regression models (adjusted β in model 3=0.122, SE=0.027, P<0.001). Furthermore, the high hsCRP group (hsCRP > 3mg/L) was associated with increasing risk of high UA1MG (adjusted OR in model 3=1.610, 95% CI 1.037-2.499, P=0.034) by logistic regression. This study suggests that serum hsCRP levels independently associate with UA1MG in patients with T2DM. Further research is warranted to elucidate these interactions.