Association Between Early Markers of Renal Injury and Type 2 Diabetic Peripheral Neuropathy

Correlation study of renal function indices with diabetic peripheral neuropathy and diabetic retinopathy in T2DM patients with normal renal function

Background

The anticipation of diabetes-related complications remains a challenge for numerous T2DM patients, as there is presently no effective method for early prediction of these complications. This study aims to investigate the association between renal function-related indicators and the occurrence of peripheral neuropathy and retinopathy in individuals diagnosed with type 2 diabetes mellitus (T2DM) who currently have normal renal function.

Methods

Patients with T2DM who met the criteria were selected from the MMC database and divided into diabetic peripheral neuropathy (DPN) and diabetic retinopathy (DR) groups, with a total of 859 and 487 patients included, respectively. Multivariate logistic regression was used to analyze the relationship between blood urea nitrogen (BUN), creatinine (Cr), uric acid (UA), urine albumin(ALB), albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and diabetic peripheral neuropathy and retinopathy. Spearman correlation analysis was used to determine the correlation between these indicators and peripheral neuropathy and retinopathy in diabetes.

Results

In a total of 221 patients diagnosed with DPN, we found positive correlation between the prevalence of DPN and eGFR (18.2, 23.3, 35.7%, p < 0.05). Specifically, as BUN (T1: references; T2:OR:0.598, 95%CI: 0.403, 0.886; T3:OR:1.017, 95%CI: 0.702, 1.473; p < 0.05) and eGFR (T1: references; T2:OR:1.294, 95%CI: 0.857, 1.953; T3:OR:2.142, 95%CI: 1.425, 3.222; p < 0.05) increased, the odds ratio of DPN also increased. Conversely, with an increase in Cr(T1: references; T2:OR:0.86, 95%CI: 0.56, 1.33; T3:OR:0.57, 95%CI: 0.36, 0.91; p < 0.05), the odds ratio of DPN decreased. Furthermore, when considering sensitivity and specificity, eGFR exhibited a sensitivity of 65.2% and specificity of 54.4%, with a 95% confidence interval of 0.568-0.656.

Conclusion

In this experimental sample, we found a clear positive correlation between eGFR and DPN prevalence.

Correlation between glycated hemoglobin A1c, urinary microalbumin, urinary creatinine, β2 microglobulin, retinol binding protein and diabetic retinopathy

BACKGROUND

Retinopathy is the most common microvascular disease of type 2 diabetes, and seriously threatens the life, health and quality of life of patients. It is worth noting that the development of diabetic retinopathy (DR) can be hidden, with few symptoms. Therefore, the preliminary screening of diabetic patients should identify DR as soon as possible, delay disease progression, and play a vital role in its diagnosis and treatment.

AIM

To investigate the correlation between glycated hemoglobin A1c (HbA1c), urinary microalbumin (U-mALB), urinary creatinine (U-CR), mALB/U-CR ratio, β2 microglobulin (β2MG), retinol binding protein (RBP) and DR.

METHODS

A total of 180 patients with type 2 diabetes mellitus attending the Second People’s Hospital of Hefei from January 2022 to August 2022 were retrospectively enrolled by ophthalmologists. Based on whether they had combined retinopathy and its degree, 68 patients with diabetes mellitus without retinopathy (NDR) were assigned to the NDR group, 54 patients with non-proliferative DR (NPDR) to the NPDR group, and 58 patients with proliferative DR to the PDR group. General data, and HbA1c, mALB, β2MG, RBP, mALB/U-CR and U-CR results were collected from the patients and compared among the groups. Pearson's correlation method was used to analyze the correlation between HbA1c, mALB, β2MG, RBP, mALB/U-CR and U-CR indices, and multiple linear regression was applied to identify the risk factors for DR. Receiver operator characteristic (ROC) curves were also drawn.

RESULTS

The differences in age, gender, systolic and diastolic blood pressure between the groups were not statistically significantly (P > 0.05), but the difference in disease duration was statistically significant (P < 0.05). The differences in fasting blood glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, and triglyceride between the groups were not statistically significant (P > 0.05). HbA1c in the PDR group was higher than that in the NPDR and NDR groups (P < 0.05). The levels of mALB, β2MG, RBP, mALB/U-CR and U-CR in the PDR group were higher than those in the NPDR and NDR groups (P < 0.05). Multiple linear regression analysis showed that disease duration, HbA1c, mALB, β2MG, RBP, mALB/U-CR and U-CR were risk factors for the development of DR. The ROC curve showed that the area under the curve (AUC) for the combination of indices (HbA1c + mALB + mALB/U-CR + U-CR + β2MG + RBP) was 0.958, with a sensitivity of 94.83% and specificity of 96.72%, which was higher than the AUC for single index prediction (P < 0.05).

CONCLUSION

HbA1c, mALB, mALB/U-CR, U-CR, β2MG and RBP can reflect the development of DR and are risk factors affecting PDR, and the combination of these six indices has predictive value for PDR.

How does diabetic peripheral neuropathy impact patients' burden of illness and the economy? A retrospective study in Beijing, China

Objective

Diabetic peripheral neuropathy (DPN) causes significant illness in patients and has a negative impact on the economy. The objective of this study is to evaluate the cost and quantity of anti-diabetic drugs needed by patients with or without DPN, as well as their variation trends in Beijing between 2016 and 2018.

Methods

This observational cross-sectional study used data on diabetic patients with outpatient medication records obtained from Beijing Medical Insurance from 2016 to 2018. The medications, comorbidities, diabetes-related complications, treatment strategies, and costs of drug treatment were compared between DPN patients and non-DPN patients.

Results

Of the 28,53,036 diabetic patients included in the study, 3,75,216 (13.15%) had DPN and 1,87,710 (50.03%) of the DPN patients were women. Compared with non-DPN patients, DPN patients used more mediations (4.7 ± 2.47 vs. 3.77 ± 2.32, p < 0.0001, in 2018) to treat related complications and comorbidities (2.03 ± 1.2 vs. 1.71 ± 1.05; 2.68 ± 1.93 vs. 2.06 ± 1.86, p < 0.0001, respectively, in 2018). The total annual costs of drug treatment were higher in DPN patients than in non-DPN patients (¥12583.25 ± 10671.48 vs. ¥9810.91 ± 9234.14, p < 0.0001, in 2018). The usage of DDP4i increased from 2.55 to 6.63% in non-DPN patients and from 4.45 to 10.09% in DPN patients from 2017 to 2018.

Conclusions

The number of comorbidities, diabetic complications, medications, and annual drug treatment costs were greater in DPN patients than in non-DPN patients.

MiR-99a-5p Inhibits the Proliferation and Migration of Human Retinal Microvascular Endothelial Cells by Targeting NOX4

Diabetic retinopathy is one of the common microvascular complications of diabetes, and it is the main cause of vision loss among working-age people. This study interpreted the roles of miR-99a-5p in DR patients and human retinal microvascular endothelial cell (hRMECs) injury induced by high glucose. The expression of miR-99a-5p was detected in patients with NDR, NPDR, and PDR. The indictive impacts of miR-99a-5p were tested by the ROC curve, and the link between miR-99a-5p and clinical information was verified by the Pearson test. HG was used to instruct cell models. The CCK-8 and transwell methods were performed to detect the proliferative and migrated cells. The targeted relationship was explained by luciferase activity. The content of miR-99a-5p was gradually lessened in NPDR and PDR patients. MiR-99a-5p might differentiate DR patients from NDR patients and PDR patients from NPDR patients. The interconnection between miR-99a-5p and clinical factors was endorsed in all DR patients. Overexpression of miR-99a-5p assuaged the abnormality of cell migration and proliferation of hRMECs triggered by HG. NOX4 was a downstream signaling component of miR-99a-5p. In conclusion, MiR-99a-5p protected hRMECs against HG damage, and the miR-99a-5p might be a novel target for diagnosis of DR.

Albuminuric diabetic kidney disease predicts foot ulcers in type 2 diabetes

Diabetic Foot Ulcers (DFU) are feared among individuals with diabetic kidney disease (DKD), but it is unclear whether they are more frequent, especially in normoalbuminuric DKD. Five hundred and twenty patients admitted in our diabetology ward from 2007 to 2017 were followed up during 54 ± 26 months. New DFUs were registered, and their relationship with the initial renal status was analyzed by LogRank and multivariate Cox regression analysis. The 520 subjects were mainly men (57.9 %), 62 ± 9 years old, with a duration of diabetes of 14 ± 10 years, HbA1c: 8.7 ± 1.8 % (72 ± 19 mmol/mol), and complications: 33.7 % macroangiopathies, 22.1 % previous foot ulcers, 44.8 % DKD, 26.9 % retinopathies. Fifty-seven new DFU occurred, mainly in subjects with DKD. DKD was related to later DFU (HR: 1.79; 95%CI: 1.05-3.07), this relationship stayed significant adjusted for age, gender, and a history of previous DFU (HR: 3.61; 95%CI: 2.11-6.18), and further adjusted for the duration of diabetes, HbA1c, BMI, arterial hypertension, and dyslipidemia. Among the 233 subjects with DKD, 129 (55.3 %) had an isolated AER > 30 mg/24H, 41 (17.6 %) had an isolated eGFR<60 mL/min/1.73 m², and 63 (27.0 %) cumulated both abnormalities. By Cox regression analysis adjusted for age and gender, albuminuric DKDs were related to later DFU: with eGFR≥60: HR: 1.91; 95%CI: 1.02-3.59, with eGFR<60: HR: 2.53; 95%CI: 1.25-5.10, whereas normoalbuminuric DKD was not: HR: 1.04; 95%CI: 0.35-3.07, despite similar rates of neuropathies, peripheral arterial diseases, and retinopathies. In people with type 2 diabetes, albuminuric DKD was associated with two to three folds increased risk of DFUs, whereas normoalbuminuric DKD was not.

Correlation between health literacy and health‐related quality of life in patients with diabetic peripheral neuropathy: The mediating role of self‐management

AIM

The aims of the study were to analyse the current situation of health literacy (HL), self-management and health-related quality of life (HRQOL) in patients with diabetic peripheral neuropathy (DPN), to explore the correlation between the three and to verify the mediating role of self-management in HL and HRQOL.

DESIGN

A cross-sectional survey.

METHODS

The convenience sampling method was used to select 401 DPN patients attending the First Hospital of Jinzhou Medical University in Liaoning Province, China, from December 2020 to December 2021 as the study population. The research instrument included socio-demographic characteristics questionnaire, Health Literacy Management Scale (HeLMS), Summary of Diabetes Self-Care Activities (SDSCA) and Short-Form 12-item Health Survey (SF-12). SPSS 25.0 was applied to the data for descriptive analysis, Pearson correlation analysis and stratified multiple regression analysis. Mediating effects were tested using SPSS PROCESS macro 4.0 software.

RESULTS

HL and self-management of DPN patients correlated positively with HRQOL. The mediation role of self-management was significant in the relationship between HL and physical and mental HRQOL (physical component summary: β = 0.26, P < 0.01; mental component summary: β = 0.18, P < 0.01), with mediating effects accounting for 35.62% and 34.62% of the total effect.

CONCLUSIONS

There was a positive correlation between HL, self-management and HRQOL in patients with DPN. Self-management plays a partially mediating role in the relationship between HL and HRQOL in DPN patients. It means that HRQOL in this population can be improved by increasing HL and thus self-management in DPN patients.

PATIENT OR PUBLIC CONTRIBUTION

None.

Sphingolipid metabolism plays a key role in diabetic peripheral neuropathy

INTRODUCTION

As the most common chronic complication of diabetes mellitus (DM), diabetic peripheral neuropathy (DPN) seriously affects the quality of life of DM patients. So, it is of great significance for the diagnosis and treatment of DPN. In recent years, there have been numerous studies on pathogenesis and biomarkers of DM, but there are few studies on the biomarkers of DPN.

OBJECTIVES

This research is intended to identify abnormal metabolic pathways, search for potential biomarkers of DPN, and provide a metabolic basis for the diagnosis and mechanism of DPN.

METHODS

Serum samples from 23 healthy controls (HC), 42 DM patients and 30 DPN patients and urine samples from 42 HC, 40 DM patients, and 30 DPN patients were collected. UPLC-Q-TOF/MS was used to analyze the samples. Potential biomarkers were screened from principal component analysis (PCA) to orthogonal partial least squares discriminant analysis (OPLS-DA) and further evaluated by receiver operating characteristic analysis (ROC). The biomarkers were then enriched and pathway analyzed.

RESULTS

12 potential DPN biomarkers were identified from patient's serum. 11 potential DPN biomarkers were identified from the patient's urine. Among them, the diagnostic ability of gluconic acid, lipoic acid, sphinganine, bilirubin, sphingosine and 4-hydroxybenzoic acid was increased by ROC analysis. Potential biomarkers suggest that the disorder of DPN metabolism may be linked to sphingolipid metabolism.

CONCLUSIONS

This research laid a theoretical foundation for the diagnosis and pathogenesis of DPN.

Advanced Glycation End-Products (AGEs): Formation, Chemistry, Classification, Receptors, and Diseases Related to AGEs

Advanced glycation end-products (AGEs) constitute a non-homogenous, chemically diverse group of compounds formed either exogeneously or endogeneously on the course of various pathways in the human body. In general, they are formed non-enzymatically by condensation between carbonyl groups of reducing sugars and free amine groups of nucleic acids, proteins, or lipids, followed by further rearrangements yielding stable, irreversible end-products. In the last decades, AGEs have aroused the interest of the scientific community due to the increasing evidence of their involvement in many pathophysiological processes and diseases, such as diabetes, cancer, cardiovascular, neurodegenerative diseases, and even infection with the SARS-CoV-2 virus. They are recognized by several cellular receptors and trigger many signaling pathways related to inflammation and oxidative stress. Despite many experimental research outcomes published recently, the complexity of their engagement in human physiology and pathophysiological states requires further elucidation. This review focuses on the receptors of AGEs, especially on the structural aspects of receptor-ligand interaction, and the diseases in which AGEs are involved. It also aims to present AGE classification in subgroups and to describe the basic processes leading to both exogeneous and endogeneous AGE formation.