Diabetic retinopathy and systemic vascular complications

How early can we detect diabetic retinopathy? A narrative review of imaging tools for structural assessment of the retina

Despite current screening models, enhanced imaging modalities, and treatment regimens, diabetic retinopathy (DR) remains one of the leading causes of vision loss in working age adults. DR can result in irreversible structural and functional retinal damage, leading to visual impairment and reduced quality of life. Given potentially irreversible photoreceptor damage, diagnosis and treatment at the earliest stages will provide the best opportunity to avoid visual disturbances or retinopathy progression. We will review herein the current structural imaging methods used for DR assessment and their capability of detecting DR in the first stages of disease. Imaging tools, such as fundus photography, optical coherence tomography, fundus fluorescein angiography, optical coherence tomography angiography and adaptive optics-assisted imaging will be reviewed. Finally, we describe the future of DR screening programmes and the introduction of artificial intelligence as an innovative approach to detecting subtle changes in the diabetic retina. CLINICAL TRIAL REGISTRATION NUMBER: N/A.

PDZK1 regulated by miR-145-5p protects against endothelial cell apoptosis and diabetic retinopathy by targeting mitochondrial function

Mitochondria are a focus of biomedical research because of their role in apoptosis and diabetic retinopathy (DR) initiation and progression. However, the detailed mechanisms underlying mitochondrial disorders and endothelial dysfunction during DR remain elusive. We identified PDZ domain containing 1 (PDZK1) as a key factor linking endothelial mitochondrial dysfunction and cell apoptosis during DR progression. PDZK1 was downregulated by high concentrations of glucose in human retinal capillary endothelial cells (HRCECs) and decreased in serum from patients with DR. PDZK1 knockout induced endothelial cell apoptosis and an irregular and disordered arrangement of retinal cells, aggravating DR. Moreover, PDZK1 loss impaired endothelial mitochondrial function with accumulated damaged mitochondria, decreased mitochondrial DNA (mtDNA) content, and increased reactive oxygen species (ROS) production. Mechanistically, mRNA sequencing showed that PDZK1 deficiency in endothelial cells interfered with mitochondrial function by increasing ATF4 (Activating Transcription Factor 4) expression. Further studies showed that PDZK1 was inhibited by miR-145-5p. The expression of miR-145-5p was significantly upregulated in the serum of patients with DR and HRCECs with high glucose concentration, leading to endothelial dysfunction and DR progression. Our results suggested that PDZK1 deficiency is crucial in mediating retinal endothelial cell apoptosis and is associated with mitochondrial dysfunction. PDZK1 overexpression by upstream miRNA, or its downstream molecule, ATF4, may represent novel therapeutic approaches for DR treatment.

Quantitative assessment of metabolic memory and its prediction of renal function decline in patients with type 2 diabetes: A retrospective observational study

AIMS

This study quantitatively assesses metabolic memory by modeling the relationship between hyperglycemic exposure and renal function decline in patients with type 2 diabetes (T2D).

METHODS

This retrospective longitudinal study included 381 Japanese patients with T2D. Hyperglycemic exposure was presented by calculating the area under the curve (AUC) for HbA1c ≥ 6 % (AUCHbA1c ≥ 6 %) during the observation period. A non-linear mixed-effects model was constructed to predict changes in estimated glomerular filtration rate (eGFR) based on AUCHbA1c ≥ 6 %.

RESULTS

The relationship between AUCHbA1c ≥ 6 % and eGFR changes was shown by a sigmoidal curve, with sex, age, diabetic retinopathy, dyslipidemia, and hypertension incorporated as covariates. The predictive utility of the model was validated using goodness-of-fit plot, visual predictive check, and bootstrap methods.

CONCLUSIONS

We developed an AUCHbA1c ≥ 6 %-based model to predict renal function decline in patients with T2D, showing that AUCHbA1c ≥ 6 % may serve as a quantitative indicator of metabolic memory.

Association of nonrefractive visual impairment with risk of all-cause and specific-cause mortality in the National Health and Nutrition Examination Survey, 1999 to 2008

OBJECTIVE

To investigate and describe the impact of nonrefractive visual impairment (NVI) and its severity on all-cause and cause-specific mortality, along with the latest estimations.

METHODS

Cox proportional hazards regression models with multiple covariate adjustments and Fine-Gray competing risk regression models assessed the risk of all-cause and specific-cause mortality. Propensity score matching (PSM) was employed to achieve covariate balance.

RESULTS

Among 7 961 participants (representing 171 383 125 non-institutionalized US individuals), baseline NVI was present in 350 participants (4.40%), with 313 (3.93%) having mild NVI and 37 (0.47%) having severe NVI. Both any NVI and Severe NVI were associated with increased all-cause and diabetes mellitus (DM)-related mortality. After PSM, the results remained consistent (for all-cause mortality: HR, 1.34; 95% CI, 1.05-1.70; for DM-related mortality: HR, 3.54; 95% CI, 1.15-10.97). Severity analysis demonstrated a significant trend between increasing NVI severity and elevated risks of all-cause and DM-specific mortality.

CONCLUSION

Our findings confirm that NVI and its severity are independent risk factors for all-cause and DM-specific mortality among the US population. This highlights the importance of regular visual acuity examinations, particularly for NVI screening, especially in individuals with diabetes.

Clinical characteristics and prognostic analysis of patients with type 2 diabetic kidney disease and non-diabetic kidney disease

Background

In diabetic patients, non-diabetic kidney disease (NDKD) may occur independently or alongside diabetic kidney disease (DKD). This study explored the utility of kidney biopsy in type 2 diabetes mellitus (T2DM) patients and the predictability of diagnosing DKD combined with NDKD using clinical and laboratory data.

Methods

This retrospective study examines medical records of T2DM patients who underwent percutaneous renal biopsy at Hangzhou TCM Hospital, Zhejiang Chinese Medical University, from 2012 to 2023. The patient's demographic, clinical, blood test and pathological examination data were retrieved from their medical records. Multivariate regression analysis evaluated predictive factors for NDKD superimposed on DKD (DKD+NDKD).

Results

A total of 285 patients were analyzed. The average age at the time of renal biopsy was 53.26 ± 10.55 years. The duration of diabetes was 93.19 ± 70.78 months. Of the patient population, 35.44% (101/285) were diagnosed with DKD alone, while 64.56% (184/285) had DKD+NDKD. Immunoglobulin A nephropathy was the most common pathological type in the DKD+NDKD group, accounting for 37.30% of the patients. Cystatin C [HR=2.688, 95% CI 1.035-6.879, P < 0.05] independently predicted the prognosis of patients with DKD+NDKD.

Conclusions

These findings suggest that cystatin C plays a role in influencing the prognosis of patients with DKD + NDKD, indicating that NDKD patients might require distinct treatment strategies compared to those with DKD alone. However, further prospective clinical trials are needed to provide more clarity on the prognosis and outcomes of diabetic patients.

Association Between Visual Acuity and Incident Atherosclerotic Cardiovascular Disease: A Longitudinal Test of Mediators

Background

Little is known about the prospective relationship between visual acuity (VA) and atherosclerotic cardiovascular disease (ASCVD) events and the extent to which this association is mediated via potential mediators. This study aims to investigate the relationship between VA and ASCVD events, including the mediation effects of potential factors.

Methods

A prospective study was conducted using data from 110,522 participants in the UK Biobank, all of whom had baseline visual acuity (VA) measurements collected between 2006 and 2010. VA was assessed using the logarithm of the minimum angle of resolution (logMAR) chart, with the better-seeing eye selected for analysis. Incident ASCVD events were obtained from hospital admissions and death records up to April 2021. The longitudinal association between VA and ASCVD was examined using Cox proportional hazards models. A four-way decomposition mediation analysis was performed to quantify the indirect effects of hypertension, diabetes, depression, and socioeconomic status in mediating the relationship between VA and ASCVD.

Results

Over an 11.13-year median follow-up, 5,496 ASCVD cases were recorded. A one-line worsening in VA (0.1 logMAR increase) was associated with an increased risk of ASCVD (HR = 1.63; 95%CI = 1.35-1.96, P < 0.001). Mediation analysis showed that hypertension, diabetes, depression, and Townsend deprivation index contributed 3.8%, 3.3%, 5.7%, and 5.9% to this association, respectively (all P < 0.05). Notably, depression was the strongest mediator, accounting for 10.0% of the association in women (P < 0.05).

Conclusions

Our study demonstrates that visual decline is associated with an increased risk of ASCVD. Early intervention through regular eye exams can help mitigate the risk of ASCVD in middle-aged and older adults. Additionally, mental health is a key mediator in the VA-ASCVD relationship, particularly among women.

A portable retina fundus photos dataset for clinical, demographic, and diabetic retinopathy prediction

This paper introduces mBRSET, the first publicly available diabetic retinopathy retina dataset captured using handheld retinal cameras in real-life, high-burden scenarios, comprising 5,164 images from 1,291 patients of diverse backgrounds. This dataset addresses the lack of ophthalmological data in low- and middle-income countries (LMICs) by providing a cost-effective and accessible solution for ocular screening and management. Portable retinal cameras enable applications outside traditional hospital settings, such as community health screenings and telemedicine consultations, thereby democratizing healthcare. Extensive metadata that are typically unavailable in other datasets, including age, sex, diabetes duration, treatments, and comorbidities, are also recorded. To validate the utility of mBRSET, state-of-the-art deep models, including ConvNeXt V2, Dino V2, and SwinV2, were trained for benchmarking, achieving high accuracy in clinical tasks diagnosing diabetic retinopathy, and macular edema; and in fairness tasks predicting education and insurance status. The mBRSET dataset serves as a resource for developing AI algorithms and investigating real-world applications, enhancing ophthalmological care in resource-constrained environments.

High Prevalence of Diabetic Retinopathy in an Outpatient Podiatry Clinic and Associated Barriers to Ophthalmic Care

Background

Diabetic retinopathy (DR) is a leading cause of vision loss among working-age adults. However, the prevalence of DR among patients with diabetic foot disease-a signal of advanced systemic diabetes complications-is underexplored. Additionally, the substantial comorbidity burden associated with diabetic foot disease may result in a higher incidence of or distinct barriers to ophthalmic care, including structural (access to healthcare), behavioral (prioritization of care), and economic (cost of care) factors, compounding risk of vision loss. This study assesses the prevalence of DR in a podiatric clinic while also investigating participant-reported barriers to routine ophthalmic follow-up.

Methods

We conducted a cross-sectional study that included patients age ≥18 (n=62) receiving diabetic foot care at an outpatient podiatric clinic in 2021 and 2022. DR status was determined through point-of-care digital retinal images or prior DR diagnosis documented in the electronic medical record. Retinal images were interpreted remotely by a board-certified ophthalmologist. Self-reported barriers to regular ophthalmic care were recorded among participants who were lost to follow-up ophthalmic care. Participants were also surveyed for favorable incentives to promote ophthalmic follow-up.

Results

Our findings revealed a high prevalence of DR, with 32 (54%) participants diagnosed with DR and 10 (17%) participants having sight-threatening DR. Notably, 17 (29%) participants were newly diagnosed with DR as a direct result of this study. Of the 62 participants enrolled, 29 (47%) were lost to ophthalmic care. All of these participations reported one or more barriers to receiving ophthalmic care, predominantly related to competing social, economic, and medical challenges, with ophthalmic care being chronically underprioritized. Financial incentives were most favored by participants as an effective means to promote ophthalmic follow-up.

Conclusion

The high prevalence of DR, especially undiagnosed DR, in conjunction with significant barriers to ophthalmic care highlights a critical need for improved screening in outpatient podiatric settings. Integrating digital fundus cameras into outpatient podiatric clinic workflow may enhance DR detection and prevent vision loss in this high-risk population. Addressing identified barriers to routine ophthalmic care may further improve the rate of follow-up care and reduce the burden of DR-related vision loss among patients with diabetic foot disease.

Retinal physiology in metabolic syndrome

Obesity is increasingly recognized not only for its systemic health impacts but also for its association with visual defects and eye diseases. This chapter explores the relationship between obesity and ocular health, highlighting the mechanisms by which metabolic dysregulation influences visual outcomes. Obesity exacerbates risk factors such as hypertension, dyslipidemia, and insulin resistance, which compromise retinal and optic nerve health. Conditions like diabetic retinopathy, age-related macular degeneration, and glaucoma are discussed in the context of obesity-related inflammation, oxidative stress, and altered vascular function, focusing on the retina as one of the body's most metabolically demanding tissues. Key pathways include adipose-derived cytokines that disrupt retinal homeostasis, and the effects of insulin resistance on retinal cells and vasculature. Furthermore, this chapter covers emerging evidence on the advances of genetic factors linking diabetic retinopathy to retinal impairments. By elucidating these interactions, we aim to provide insight into preventive and therapeutic strategies that could mitigate vision loss among individuals with obesity.

Lipoxin A4 (LXA4) as a Potential Drug for Diabetic Retinopathy

The purpose of this review is to propose that lipoxin A4 (LXA4), derived from arachidonic acid (AA), a potent anti-inflammatory, cytoprotective, and wound healing agent, may be useful to prevent and manage diabetic retinopathy (DR). LXA4 suppresses inappropriate angiogenesis and the production of pro-inflammatory prostaglandin E2 (PGE2), leukotrienes (LTs), 12-HETE (12-hydroxyeicosatetraenoic acid), derived from AA by the action of 12-lioxygenase (12-LOX)) interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), as well as the expression of NF-κB, inducible NO (nitric oxide) synthase (iNOS), cyclooxygenase-2 (COX-2), intracellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF)-factors that play a role in DR. Thus, the intravitreal injection of LXA4 may form a new approach to the treatment of DR and other similar conditions such as AMD (age-associated macular degeneration) and SARS-CoV-2-associated hyperinflammatory immune response in the retina. The data for this review are derived from our previous work conducted in individuals with DR and from various publications on LXA4, inflammation, and DR.

Systemic and Cardiac Microvascular Dysfunction in Hypertension

Hypertension exerts a profound impact on the microcirculation, causing both structural and functional alterations that contribute to systemic and organ-specific vascular damage. The microcirculation, comprising arterioles, capillaries, and venules with diameters smaller than 20 μm, plays a fundamental role in oxygen delivery, nutrient exchange, and maintaining tissue homeostasis. In the context of hypertension, microvascular remodeling and rarefaction result in reduced vessel density and elasticity, increasing vascular resistance and driving end-organ damage. The pathophysiological mechanisms underlying hypertensive microvascular dysfunction include endothelial dysfunction, oxidative stress, and excessive collagen deposition. These changes impair nitric oxide (NO) bioavailability, increase reactive oxygen species (ROS) production, and promote inflammation and fibrosis. These processes lead to progressive vascular stiffening and dysfunction, with significant implications for multiple organs, including the heart, kidneys, brain, and retina. This review underscores the pivotal role of microvascular dysfunction in hypertension-related complications and highlights the importance of early detection and therapeutic interventions. Strategies aimed at optimizing blood pressure control, improving endothelial function, and targeting oxidative stress and vascular remodeling are critical to mitigating the systemic consequences of hypertensive microvascular damage and reducing the burden of related cardiovascular and renal diseases.

Prediction of Incident Diabetic Retinopathy in Adults With Type 1 Diabetes Using Machine Learning Approach: An Exploratory Study

BACKGROUND

Early detection and intervention are crucial for preventing vision-threatening diabetic retinopathy (DR) in adults with type 1 diabetes (T1D). This exploratory study uses machine learning on continuous glucose monitoring (CGM) data to identify factors influencing DR and predict high-risk individuals for timely intervention.

METHODS

Between June 2018 and March 2022, adults with T1D with incident DR or no retinopathy (control) were identified. The CGM data were collected retrospectively for up to seven years before the date of defining incident DR or no retinopathy. A mixture of three machine learning algorithms was trained and evaluated in two different scenarios, using different glycemic features extracted from CGM traces (scenario 1), and the two principal components (two PCs; exposure to hyperglycemia and hypoglycemia risk) of those features (scenario 2). Classifiers were evaluated through 10-fold cross-validation using the receiver operating characteristic area under the curve (AUC-ROC) to select the best classification model.

RESULTS

The CGM data of 30 adults with incident DR (mean±SD age of 21.2±9.4 years, glycated hemoglobin [HbA1c] of 8.6%±1.0%, and body mass index [BMI] of 24.5±4.8 kg/m2) and 30 adults without DR (age of 41.8±14.7 years, HbA1c of 7.0%±0.9%, and BMI of 26.2±3.6 kg/m2) were included in this analysis. In scenario 2, classifiers outperformed scenario 1, resulting in an average AUC-ROC increase to 0.92 for two of three models, indicating that the two PCs captured vital classification data, representing the most discriminative aspects and enhancing model performance.

CONCLUSION

Machine learning approaches using CGM data may have potential to aid in identifying adults with T1D at risk of DR.

Integrated image-based deep learning and language models for primary diabetes care

Primary diabetes care and diabetic retinopathy (DR) screening persist as major public health challenges due to a shortage of trained primary care physicians (PCPs), particularly in low-resource settings. Here, to bridge the gaps, we developed an integrated image-language system (DeepDR-LLM), combining a large language model (LLM module) and image-based deep learning (DeepDR-Transformer), to provide individualized diabetes management recommendations to PCPs. In a retrospective evaluation, the LLM module demonstrated comparable performance to PCPs and endocrinology residents when tested in English and outperformed PCPs and had comparable performance to endocrinology residents in Chinese. For identifying referable DR, the average PCP's accuracy was 81.0% unassisted and 92.3% assisted by DeepDR-Transformer. Furthermore, we performed a single-center real-world prospective study, deploying DeepDR-LLM. We compared diabetes management adherence of patients under the unassisted PCP arm (n = 397) with those under the PCP+DeepDR-LLM arm (n = 372). Patients with newly diagnosed diabetes in the PCP+DeepDR-LLM arm showed better self-management behaviors throughout follow-up (P < 0.05). For patients with referral DR, those in the PCP+DeepDR-LLM arm were more likely to adhere to DR referrals (P < 0.01). Additionally, DeepDR-LLM deployment improved the quality and empathy level of management recommendations. Given its multifaceted performance, DeepDR-LLM holds promise as a digital solution for enhancing primary diabetes care and DR screening.

Association of urinary creatinine excretion and body mass index with diabetic retinopathy in patients with type 2 diabetes

This study aimed to determine whether urinary creatinine excretion rate (CER), a marker of muscle mass, is associated with diabetic retinopathy in individuals with type 2 diabetes and to ascertain whether this putative association depends on body mass index (BMI). This cross sectional study evaluated 2035 individuals with type 2 diabetes. Twenty-four-hour urine was collected. Individuals with diabetic retinopathy had lower CER and BMI values than those without. Patients in higher CER quartiles had higher BMI values and a lower prevalence of diabetic retinopathy. A significant relationship between CER and diabetic retinopathy persisted, even after adjusting for traditional risk factors, including glycated hemoglobin, diabetes duration, and hypertension, in multivariable analysis. Further adjustment for BMI did not significantly alter the association between CER and diabetic retinopathy. This study suggests that CER is inversely associated with diabetic retinopathy in individuals with type 2 diabetes, and this association is independent of BMI.

The association between composite dietary antioxidant index and diabetic retinopathy in type 2 diabetic patients: evidence from the NHANES

Background

Although diabetic retinopathy (DR) is closely related to dietary patterns and oxidative stress, there is little research on the relationship between the compound dietary antioxidant index (CDAI) and DR. This study aims to fill this gap by analyzing data from the National Health and Nutrition Examination Survey (NHANES) to explore the association between CDAI and DR in patients with type 2 diabetes, in order to provide a basis for dietary guidance to prevent DR.

Methods

Data for this study was obtained from NHANES conducted between 1999 and 2020. Information regarding dietary intake was collected through 24 h dietary recall interviews. Multivariate logistic regression analyses and restricted cubic splines (RCS) were employed to explore the association between CDAI and DR. Furthermore, subgroup analyses were conducted to further examine the relationship.

Results

In this study, a total of 2,158 participants were included, with a mean age of 58.87 years. After adjusting for all potential confounding factors, multivariate logistic regression analyses consistently demonstrated a negative correlation between CDAI and DR (OR = 0.94, 95%CI: 0.90-0.98, p = 0.007). Specifically, individuals in the highest quartile of CDAI had a significantly reduced risk of DR compared to those in the lowest quartile (OR = 0.51, 95%CI: 0.34-0.75, p < 0.001). The RCS analyses further confirmed the linear negative correlation between CDAI and DR (non-linear p = 0.101). Additionally, subgroup analyses provided further evidence for the robustness of this association across different subpopulations.

Conclusion

Our study highlights the linear negative correlation between CDAI and DR in type 2 diabetic patients. Further prospective studies are still needed in the future to confirm the role of CDAI in the risk of developing DR.

BRSET: A Brazilian Multilabel Ophthalmological Dataset of Retina Fundus Photos

INTRODUCTION

The Brazilian Multilabel Ophthalmological Dataset (BRSET) addresses the scarcity of publicly available ophthalmological datasets in Latin America. BRSET comprises 16,266 color fundus retinal photos from 8,524 Brazilian patients, aiming to enhance data representativeness, serving as a research and teaching tool. It contains sociodemographic information, enabling investigations into differential model performance across demographic groups.

METHODS

Data from three São Paulo outpatient centers yielded demographic and medical information from electronic records, including nationality, age, sex, clinical history, insulin use, and duration of diabetes diagnosis. A retinal specialist labeled images for anatomical features (optic disc, blood vessels, macula), quality control (focus, illumination, image field, artifacts), and pathologies (e.g., diabetic retinopathy). Diabetic retinopathy was graded using International Clinic Diabetic Retinopathy and Scottish Diabetic Retinopathy Grading. Validation used a ConvNext model trained during 50 epochs using a weighted cross entropy loss to avoid overfitting, with 70% training (20% validation), and 30% testing subsets. Performance metrics included area under the receiver operating curve (AUC) and Macro F1-score. Saliency maps were calculated for interpretability.

RESULTS

BRSET comprises 65.1% Canon CR2 and 34.9% Nikon NF5050 images. 61.8% of the patients are female, and the average age is 57.6 (± 18.26) years. Diabetic retinopathy affected 15.8% of patients, across a spectrum of disease severity. Anatomically, 20.2% showed abnormal optic discs, 4.9% abnormal blood vessels, and 28.8% abnormal macula. A ConvNext V2 model was trained and evaluated BRSET in four prediction tasks: "binary diabetic retinopathy diagnosis (Normal vs Diabetic Retinopathy)" (AUC: 97, F1: 89); "3 class diabetic retinopathy diagnosis (Normal, Proliferative, Non-Proliferative)" (AUC: 97, F1: 82); "diabetes diagnosis" (AUC: 91, F1: 83); "sex classification" (AUC: 87, F1: 70).

DISCUSSION

BRSET is the first multilabel ophthalmological dataset in Brazil and Latin America. It provides an opportunity for investigating model biases by evaluating performance across demographic groups. The model performance of three prediction tasks demonstrates the value of the dataset for external validation and for teaching medical computer vision to learners in Latin America using locally relevant data sources.

Association of Vascular Endothelial Growth Factor (VEGF) and Mouse Model Minute 2 (MDM2) Polymorphisms With Diabetic Retinopathy in a Northwest Indian Population: A Case-Control Study

INTRODUCTION

Diabetic retinopathy (DR), a microvascular complication of type 2 diabetes (T2D), results from complex interactions of genetic and environmental factors. Vascular endothelial growth factor (VEGF) and mouse model minute 2 (MDM2)are upregulated in the retina due to diabetes, which increases the risk of DR. VEGFA and MDM2 genetic variations can influence DR risk. The present case-control study was conducted to evaluate the association of VEGFA and MDM2 promoter variants with DR in a population from Punjab, Northwest India.

METHODS

A total of 414 DR patients, 425 T2D patients without DR, and 402 healthy controls were screened for VEGFA -2578C/A (rs699947), VEGFA -2549I/D (rs35569394), VEGFA -7C/T (rs25648), and MDM2 rs3730485 polymorphisms using polymerase chain reaction (PCR)-based methods.

RESULTS

VEGFA -2549 I allele (OR = 1.35 (1.00-1.81), p = 0.043) and II genotype (OR = 1.78 (1.00-3.15), p = 0.047) were significantly associated with increased risk of DR. VEGFA -7 CT genotype conferred reduced risk of DR (OR = 0.28 (0.20-0.38); p = <0.001). VEGFA -2578 and MDM2 rs3730485 showed no significant association with DR. A-I-T (OR = 0.30 (0.20-0.44); p = <0.001) and C-D-T (OR = 0.33 (0.16-0.65); p = 0.002) haplotypes of rs699947-rs35569394-rs25648 polymorphisms showed decreased risk of DR.

CONCLUSIONS

I allele and II genotype of VEGFA -2549, CT genotype of VEGFA -7, and C-I-C and A-D-C haplotypes of rs699947-rs35569394-rs25648 polymorphisms were significantly associated with DR risk in a Northwest Indian population. This is the first study worldwide to report DR risk with VEGFA promoter variants together.

Identification of biomarkers associated with ferroptosis in diabetic retinopathy based on WGCNA and machine learning

Objective: Diabetic retinopathy (DR) is a chronic progressive eye disease that affects millions of diabetic patients worldwide, and ferroptosis may contribute to the underlying mechanisms of DR. The main objective of this work is to explore key genes associated with ferroptosis in DR and to determine their feasibility as diagnostic markers. Methods: WGCNA identify the most relevant signature modules in DR. Machine learning methods were used to de-screen the feature genes. ssGSEA calculated the scoring of immune cells in the DR versus control samples and compared the associations with the core genes by Spearman correlation. Results: We identified 2,897 differential genes in DR versus normal samples. WGCNA found tan module to have the highest correlation with DR patients. Finally, 20 intersecting genes were obtained from differential genes, tan module and iron death genes, which were screened by LASSO and SVM-RFE method, and together identified 6 genes as potential diagnostic markers. qPCR verified the expression and ROC curves confirmed the diagnostic accuracy of the 6 genes. In addition, our ssGSEA scoring identified these 6 core genes as closely associated with immune infiltrating cells. Conclusion: In conclusion, we analyzed for the first time the potential link of iron death in the pathogenesis of DR. This has important implications for future studies of iron death-mediated pro-inflammatory immune mechanisms.

Advanced Mass Spectrometry-Based Biomarker Identification for Metabolomics of Diabetes Mellitus and Its Complications

Over the years, there has been notable progress in understanding the pathogenesis and treatment modalities of diabetes and its complications, including the application of metabolomics in the study of diabetes, capturing attention from researchers worldwide. Advanced mass spectrometry, including gas chromatography-tandem mass spectrometry (GC-MS/MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and ultra-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS), etc., has significantly broadened the spectrum of detectable metabolites, even at lower concentrations. Advanced mass spectrometry has emerged as a powerful tool in diabetes research, particularly in the context of metabolomics. By leveraging the precision and sensitivity of advanced mass spectrometry techniques, researchers have unlocked a wealth of information within the metabolome. This technology has enabled the identification and quantification of potential biomarkers associated with diabetes and its complications, providing new ideas and methods for clinical diagnostics and metabolic studies. Moreover, it offers a less invasive, or even non-invasive, means of tracking disease progression, evaluating treatment efficacy, and understanding the underlying metabolic alterations in diabetes. This paper summarizes advanced mass spectrometry for the application of metabolomics in diabetes mellitus, gestational diabetes mellitus, diabetic peripheral neuropathy, diabetic retinopathy, diabetic nephropathy, diabetic encephalopathy, diabetic cardiomyopathy, and diabetic foot ulcers and organizes some of the potential biomarkers of the different complications with the aim of providing ideas and methods for subsequent in-depth metabolic research and searching for new ways of treating the disease.

Analysis of the association between high antioxidant diet and lifestyle habits and diabetic retinopathy based on NHANES cross-sectional study

Oxidative stress plays a crucial role in increasing the risk of developing diabetic retinopathy (DR). The oxidative balance score (OBS) and the composite dietary antioxidant index (CDAI) are two tools for assessing the effects of diet and lifestyle on oxidative stress. The aim of this study was to investigate the association between OBS, CDAI and the occurrence of DR. After controlling for potential confounders, OBS was negatively associated with DR with an odds ratio (OR) of 0.976 and a 95% confidence interval (CI) of 0.956-0.996, suggesting that for every unit increase in OBS, the risk of DR was reduced by 2.4%. In contrast, the relationship between OBS and CDAI was not significant (P > 0.05), suggesting that it was OBS, not CDAI, that contributed to the reduced risk of diabetic retinopathy. After adjusting for potential confounders, OBS was negatively associated with DR (OR: 0.976; 95% CI 0.956-0.996), but this association was not found in CDAI (P > 0.05), suggesting that for every one-unit increase in OBS, there was a 2.4% reduction in the risk of developing DR. This study suggests that a diet and lifestyle high in OBS reduces the risk of developing DR, which provides a rationale for nutritional interventions to prevent DR.

Extrapulmonary manifestations of pulmonary arterial hypertension

INTRODUCTION

Extrapulmonary manifestations of pulmonary arterial hypertension (PAH) may play a critical pathobiological role and a deeper understanding will advance insight into mechanisms and novel therapeutic targets. This manuscript reviews our understanding of extrapulmonary manifestations of PAH.

AREAS COVERED

A group of experts was assembled and a complimentary PubMed search performed (October 2023 - March 2024). Inflammation is observed throughout the central nervous system and attempts at manipulation are an encouraging step toward novel therapeutics. Retinal vascular imaging holds promise as a noninvasive method of detecting early disease and monitoring treatment responses. PAH patients have gut flora alterations and dysbiosis likely plays a role in systemic inflammation. Despite inconsistent observations, the roles of obesity, insulin resistance and dysregulated metabolism may be illuminated by deep phenotyping of body composition. Skeletal muscle dysfunction is perpetuated by metabolic dysfunction, inflammation, and hypoperfusion, but exercise training shows benefit. Renal, hepatic, and bone marrow abnormalities are observed in PAH and may represent both end-organ damage and disease modifiers.

EXPERT OPINION

Insights into systemic manifestations of PAH will illuminate disease mechanisms and novel therapeutic targets. Additional study is needed to understand whether extrapulmonary manifestations are a cause or effect of PAH and how manipulation may affect outcomes.

Associations between depression and diabetic retinopathy in the National Health and Nutrition Examination Survey, 2011 to 2018

INTRODUCTION

Diabetic retinopathy (DR) is a vision-threatening complication of diabetes mellitus (DM). The relationship between depression and DR is unclear, and prior studies are limited by small sample sizes at single centers. This retrospective, cross-sectional study assessed the prevalence of and associations between depression and DR in the US using the National Health and Nutrition Examination Survey for 2011 to 2018.

METHODS

We collected information on the demographic characteristics, medical conditions, and examination data of NHANES participants with DM. We performed weighted analysis to estimate national prevalence and multivariate analysis to assess the relationship between depression and DR.

RESULTS

Of the 22,618 participants included, the prevalence of DM and DR were 3146 (13.9%) and 664 (2.9%). The prevalence of depression was 14.2% in DM only and 19.3% in DR (P = 0.006) with greater severity in the DR group (P < 0.001). After adjusting for comorbidities, DR was no longer significantly associated with depression. Depression was not associated with differences in disease management, although participants with depression had poorer self-perceived health status (P < 0.001).

CONCLUSIONS

Depression is more prevalent in individuals with DR than those with DM only. The relationship between depression and DR may be mediated by additional medical comorbidities, but further studies are needed.

Longitudinal Quantitative Ultrawidefield Angiographic Features in Diabetic Retinopathy Treated with Aflibercept from the Intravitreal Aflibercept as Indicated by Real-Time Objective Imaging to Achieve Diabetic Retinopathy Improvement Trial

OBJECTIVE

To report longitudinal trends of quantitative ultrawidefield fluorescein angiography (qUWFA) biomarkers in the Intravitreal Aflibercept as Indicated by Real-Time Objective Imaging to Achieve Diabetic Retinopathy Improvement (PRIME) diabetic retinopathy (DR) clinical trial.

DESIGN

Post hoc analysis of the PRIME prospective randomized DR clinical trial comparing intravitreal aflibercept treatment based on the DR severity score (DRSS) or quantitative leakage index for DR improvement (ClinicalTrials.gov identifier: NCT03531294).

PARTICIPANTS

Patients were enrolled with a DRSS level of 47A to 71A and best-corrected visual acuity of 20/800 or better. Key exclusion criteria were previous intravitreal injection, panretinal photocoagulation, vitrectomy, central-involving macular edema, or vitreous hemorrhage.

METHODS

A previously validated, machine learning-based qUWFA analysis platform was used for panretinal leakage index assessment and differentiation of generalized and perivascular leakage phenotypes. Additionally, microaneurysm count and ischemic index were quantified in panretinal and macular regions. The trends in these biomarkers and therapeutic response were studied over 1 year.

MAIN OUTCOME MEASURES

Longitudinal trends of qUWFA biomarkers. The impact of these qUWFA metrics on treatment response was assessed by studying their associations with time to 2-step DRSS improvement and number of treatment-free days.

RESULTS

Forty eyes from 40 subjects with DR were enrolled. Lower baseline generalized leakage was noted in eyes that attained the 2-step DRSS improvement in < 16 weeks (1.9% vs. 2.8%; P = 0.026). Baseline macular perivascular-generalized leakage ratio had a significant correlation with the number of treatment-free days (r = 0.4; P = 0.012). At the end of 1 year, therapy significantly reduced the mean panretinal (3.9% vs. 5.8%; P = 0.002) and macular (6.2% vs. 12.2%; P = 0.008) generalized leakage indices compared with baseline, as well as the mean panretinal perivascular leakage index (1.5% vs. 2.3%; P = 0.002). The mean panretinal ischemic index demonstrated a small but likely clinically insignificant decrease from 12.5% at baseline to 11.6% at year 1 (P = 0.016).

CONCLUSIONS

Down-trending leakage indices and microaneurysm counts were demonstrated over 1 year of anti-VEGF therapy. At baseline, DR eyes with lower generalized leakage responded to therapy more rapidly. Eyes with greater perivascular leakage relative to generalized leakage showed a longer-lasting anti-VEGF treatment response.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Diabetic Retinopathy and Cardiovascular Disease: A Literature Review

Diabetic complications can be divided into macrovascular complications such as cardiovascular disease and cerebrovascular disease and microvascular complications such as diabetic retinopathy, diabetic nephropathy and diabetic neuropathy. Among them, cardiovascular disease (CVD) is an important cause of death in diabetic patients. Diabetes retinopathy (DR) is one of the main reasons for the increasing disability rate of diabetes. In recent years, some studies have found that because DR and CVD have a common pathophysiological basis, the occurrence of DR and CVD are inseparable, and to a certain extent, DR can predict the occurrence of CVD. With the development of technology, the fundus parameters of DR can be quantitatively analyzed as an independent risk factor of CVD. In addition, the cytokines related to DR can also be used for early screening of DR. Although many advances have been made in the treatment of CVD, its situation of prevention and treatment is still not optimistic. This review hopes to discuss the feasibility of DR in predicting CVD from the common pathophysiological mechanism of DR and CVD, the new progress of diagnostic techniques for DR, and the biomarkers for early screening of DR.

Explainable Artificial Intelligence Paves the Way in Precision Diagnostics and Biomarker Discovery for the Subclass of Diabetic Retinopathy in Type 2 Diabetics

Diabetic retinopathy (DR), a common ocular microvascular complication of diabetes, contributes significantly to diabetes-related vision loss. This study addresses the imperative need for early diagnosis of DR and precise treatment strategies based on the explainable artificial intelligence (XAI) framework. The study integrated clinical, biochemical, and metabolomic biomarkers associated with the following classes: non-DR (NDR), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) in type 2 diabetes (T2D) patients. To create machine learning (ML) models, 10% of the data was divided into validation sets and 90% into discovery sets. The validation dataset was used for hyperparameter optimization and feature selection stages, while the discovery dataset was used to measure the performance of the models. A 10-fold cross-validation technique was used to evaluate the performance of ML models. Biomarker discovery was performed using minimum redundancy maximum relevance (mRMR), Boruta, and explainable boosting machine (EBM). The predictive proposed framework compares the results of eXtreme Gradient Boosting (XGBoost), natural gradient boosting for probabilistic prediction (NGBoost), and EBM models in determining the DR subclass. The hyperparameters of the models were optimized using Bayesian optimization. Combining EBM feature selection with XGBoost, the optimal model achieved (91.25 ± 1.88) % accuracy, (89.33 ± 1.80) % precision, (91.24 ± 1.67) % recall, (89.37 ± 1.52) % F1-Score, and (97.00 ± 0.25) % the area under the ROC curve (AUROC). According to the EBM explanation, the six most important biomarkers in determining the course of DR were tryptophan (Trp), phosphatidylcholine diacyl C42:2 (PC.aa.C42.2), butyrylcarnitine (C4), tyrosine (Tyr), hexadecanoyl carnitine (C16) and total dimethylarginine (DMA). The identified biomarkers may provide a better understanding of the progression of DR, paving the way for more precise and cost-effective diagnostic and treatment strategies.

The Role of Genetic Polymorphisms in Diabetic Retinopathy: Narrative Review

Diabetic retinopathy (DR) is renowned as a leading cause of visual loss in working-age populations with its etiopathology influenced by the disturbance of biochemical metabolic pathways and genetic factors, including gene polymorphism. Metabolic pathways considered to have an impact on the development of the disease, as well as genes and polymorphisms that can affect the gene expression, modify the quantity and quality of the encoded product (protein), and significantly alter the metabolic pathway and its control, and thus cause changes in the functioning of metabolic pathways. In this article, the screening of chromosomes and the most important genes involved in the etiology of diabetic retinopathy is presented. The common databases with manuscripts published from January 2000 to June 2023 have been taken into consideration and chosen. This article indicates the role of specific genes in the development of diabetic retinopathy, as well as polymorphic changes within the indicated genes that may have an impact on exacerbating the symptoms of the disease. The collected data will allow for a broader look at the disease and help to select candidate genes that can become markers of the disease.

Prevalence and Risk Factors of Retinopathy in Type 1 Diabetes: A Cross-Sectional Study

Introduction Diabetic retinopathy (DR) is a severe complication of diabetes. It remains a major cause of visual impairment and blindness, especially in young people. It is a silent affection that only becomes symptomatic at the onset of complications. Our study aimed to estimate the prevalence of retinopathy in patients with type 1 diabetes mellitus (T1DM) and evaluate the associated risk factors in our population. Materials and methods A descriptive and analytical study, with a cross-sectional study involving 359 patients with type 1 diabetes, was followed up in the Department of Endocrinology, Diabetology, and Nutrition of the University Hospital Center Mohammed VI Oujda, Morocco. Data were collected from medical records and analyzed by binary logistic regression using IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp. Results The average age of our patients was 24.2 ± 11.4 years. The mean duration of diabetes was 11.8±4.4 years. The average glycated hemoglobin (HbA1c) at admission was 10.1 ± 2.4%. DR was found in 30% of patients, including 28.6% with minimal non-proliferative diabetic retinopathy (NPDR), 19.1% with moderate NPDR, 19.1% with severe NPDR, and 33.3% with proliferative DR. Patients with diabetic retinopathy appear to have a longer duration of diabetes (13.05±9.05 vs. 10.6±8.07 years). The longer duration of diabetes, neuropathy, and nephropathy was significantly associated with diabetic retinopathy (p=0.02, p=0.002, and p=0.0001, respectively). Conclusion The frequency of diabetic retinopathy increases with age, poor glycemic control, and the duration of diabetes. Therefore, cooperation between diabetologists and ophthalmologists is essential for making an early diagnosis and providing early treatment.

Study of Foveal Avascular Zone Growth in Individuals With Mild Diabetic Retinopathy by Optical Coherence Tomography

Purpose

The purpose of this study was to investigate the association between foveal vessels and retinal thickness in individuals with diabetic retinopathy (DR) and control subjects, and to reveal foveal avascular zone (FAZ) growth in early individuals with DR.

Methods

The regions with a thickness less than 60 µm were marked from the intima thickness maps and named FAZThic. The avascular zones extracted from the deep vascular plexus were designated as FAZAngi. The boundary of the two FAZ forms a ring region, which we called FAZRing. The FAZ growth rate was defined as the ratio of the FAZRing area to the FAZThic area. Thirty healthy controls and 30 individuals with mild nonproliferative DR were recruited for this study.

Results

The FAZThic area in individuals with mild DR and control subjects showed similar distribution. The FAZAngi area in individuals with mild DR are higher than that in control subjects on the whole, but there was no significant difference (P > 0.05). The FAZRing area in individuals with mild DR was significantly higher than that in control subjects (P < 0.001). However, there is still a small amount of overlap data between the two groups. For the FAZ growth rate, the individuals with mild DR were also significantly larger than the control subjects (P < 0.001). But there were no overlapping data between the two groups.

Conclusions

The growth of FAZ in individuals with mild DR can be inferred by comparing FAZAngi with FAZThic. This method minimizes the impact of individual variations and helps researchers to understand the progression mechanism of DR more deeply.

3D-FVS: construction and application of three-dimensional fundus vascular structure model based on single image features

BACKGROUND

Fundus microvasculature may be visually observed by ophthalmoscope and has been widely used in clinical practice. Due to the limitations of available equipment and technology, most studies only utilized the two-dimensional planar features of the fundus microvasculature.

METHODS

This study proposed a novel method for establishing the three-dimensional fundus vascular structure model and generating hemodynamic characteristics based on a single image. Firstly, the fundus vascular are segmented through our proposed network framework. Then, the length and width of vascular segments and the relationship among the adjacent segments are collected to construct the three-dimensional vascular structure model. Finally, the hemodynamic model is generated based on the vascular structure model, and highly correlated hemodynamic features are selected to diagnose the ophthalmic diseases.

RESULTS

In fundus vascular segmentation, the proposed network framework obtained 98.63% and 97.52% on Area Under Curve (AUC) and accuracy respectively. In diagnosis, the high correlation features extracted based on the proposed method achieved 95% on accuracy.

CONCLUSIONS

This study demonstrated that hemodynamic features filtered by relevance were essential for diagnosing retinal diseases. Additionally, the method proposed also outperformed the existing models on the levels of retina vessel segmentation. In conclusion, the proposed method may represent a novel way to diagnose retinal related diseases, which can analysis two-dimensional fundus pictures by extracting heterogeneous three-dimensional features.

High- and normal-protein diets improve body composition and glucose control in adults with type 2 diabetes: a randomized trial

OBJECTIVE

Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein sources, especially red meat, impact weight loss-induced T2D management is unknown. This trial compared an HP diet including beef and a normal-protein (NP) diet without red meat for weight loss, body composition changes, and glucose control in individuals with T2D.

METHODS

A total of 106 adults (80 female) with T2D consumed an HP (40% protein) diet with ≥4 weekly servings of lean beef or an NP (21% protein) diet excluding red meat during a 52-week weight loss intervention. Body weight, body composition, and cardiometabolic parameters were measured before and after intervention.

RESULTS

Weight loss was not different between the HP (-10.2 ± 1.6 kg) and NP (-12.7 ± 4.8 kg, p = 0.336) groups. Both groups reduced fat mass and increased fat-free mass percent. Hemoglobin A1c, glucose, insulin, insulin resistance, blood pressure, and triglycerides improved, with no differences between groups.

CONCLUSIONS

The lack of observed effects of dietary protein and red meat consumption on weight loss and improved cardiometabolic health suggests that achieved weight loss, rather than diet composition, should be the principal target of dietary interventions for T2D management.

Glucose-Responsive Microgel Comprising Conventional Insulin and Curcumin-Laden Nanoparticles: a Potential Combination for Diabetes Management

Successful management of type 2 diabetes mellitus (T2DM), a complex and chronic disease, requires a combination of anti-hyperglycemic and anti-inflammatory agents. Here, we have conceptualized and tested an integrated "closed-loop mimic" in the form of a glucose-responsive microgel (GRM) based on chitosan, comprising conventional insulin (INS) and curcumin-laden nanoparticles (nCUR) as a potential strategy for effective management of the disease. In addition to mimicking the normal, on-demand INS secretion, such delivery systems display an uninterrupted release of nCUR to combat the inflammation, oxidative stress, lipid metabolic abnormality, and endothelial dysfunction components of T2DM. Additives such as gum arabic (GA) led to a fivefold increased INS loading capacity compared to GRM without GA. The GRMs showed excellent in vitro on-demand INS release, while a constant nCUR release is observed irrespective of glucose concentrations. Thus, this study demonstrates a promising drug delivery technology that can simultaneously, and at physiological/pathophysiological relevance, deliver two drugs of distinct physicochemical attributes in the same formulation.

Association between Severity of Diabetic Retinopathy and Cardiac Function in Patients with Type 2 Diabetes

Background

The purpose of this research was to assess the relationship between the severity of diabetic retinopathy (DR) and indexes of left ventricle (LV) structure and function in type 2 diabetes mellitus (T2DM).

Methods

Retrospective analysis of 790 patients with T2DM and preserved LV ejection fraction. Retinopathy stages were classified as no DR, early nonproliferative DR, moderate to severe nonproliferative DR, or proliferative DR. The electrocardiogram was used to assess myocardial conduction function. Echocardiography was used to evaluate myocardial structure and function.

Results

Patients were divided into three groups based on the DR status: no DR group (NDR, n = 475), nonproliferative DR group (NPDR, n = 247), and proliferative DR group (PDR, n = 68). LV interventricular septal thickness (IVST) increased significantly with more severe retinopathy (NDR: 10.00 ± 1.09; NPDR: 10.42 ± 1.21; and PDR: 10.66 ± 1.58; P < 0.001). Multivariate logistic regression analysis showed that the significant correlation of IVST persisted between subjects with no retinopathy and proliferative DR (odds ratio = 1.35, P = 0.026). Indices of myocardial conduction function were assessed by electrocardiogram differences among groups of retinopathy (all P < 0.001). In multiple-adjusted linear regression analyses, the increasing degree of retinopathy was closely correlated with heart rate (β = 1.593, P = 0.027), PR interval (β = 4.666, P = 0.001), and QTc interval (β = 8.807, P = 0.005).

Conclusion

The proliferative DR was independently associated with worse cardiac structure and function by echocardiography. Furthermore, the severity of retinopathy significantly correlated with abnormalities of the electrocardiogram in patients with T2DM.

Multimodal Retinal Imaging in Patients with Diabetes Mellitus and Association with Cerebrovascular Disease

INTRODUCTION

This study aimed to evaluate the association between macular optical coherence tomography angiography (OCT-A) metrics, characteristics of ultrawide field (UWF) imaging, and cerebrovascular disease in patients with diabetes mellitus (DM) with different stages of diabetic retinopathy (DR).

METHODS

516 eyes of 258 DM patients were enrolled in two centers (Milan and Belfast). UWF color fundus photos (CFPs) were obtained with Optos California (Optos, PLC) and graded for both DR severity and predominantly peripheral lesions presence (>50% of CFP lesions) by two independent graders. OCT-A (3 × 3 mm), available in 252 eyes of 136 patients, was used to determine perimeter, area, and circularity index of the foveal avascular zone and vessel density (VD); perfusion density (PD); fractal dimension on superficial, intermediate (ICP), and deep capillary plexuses; flow voids (FVs) in the choriocapillaris.

RESULTS

Out of 516 eyes, 108 eyes (20.9%) had no DR, and 6 eyes were not gradable. The remaining 402 eyes were as follows: 10.3% (53) had mild nonproliferative DR (NPDR), 38.2% (197) had moderate NPDR, 11.8% (61) had severe NPDR, and 17.6% (91) had proliferative DR. A worse DR stage was associated with a history of stroke (p = 0.044). Logistic regression analysis after taking into account sex, type of DM, age, DM duration, and OCT-A variables found that PD and VD on ICP were significantly associated with presence of stroke and DR severity.

CONCLUSION

OCT-A metrics show an association with the presence of cerebrovascular complications, providing potentially useful parameters to estimate vascular risk in patients with DM.

Impact of individual microvascular disease on the risks of macrovascular complications in type 2 diabetes: a nationwide population-based cohort study

BACKGROUND

This study compared the risks of cardiovascular morbidity and mortality between patients with type 2 diabetes (T2D) with and without microvascular diseases, and between matched patients with microvascular diseases.

METHODS

We identified newly diagnosed type 2 diabetes patients from National Health Insurance Research Database in Taiwan from January 1, 2008, to December 31, 2019. Propensity score matching was applied to construct matched pairs of patients with diabetic kidney disease, retinopathy, or neuropathy. Multivariable Cox proportional-hazard models were adopted to compare the risks of cardiovascular morbidity and mortality.

RESULTS

Patients with microvascular disease had a significantly higher risk of cardiovascular morbidities and mortality than those without microvascular disease. Among the matched cohorts, patients with diabetic retinopathy had a significantly higher risk of stroke development than those with diabetic kidney disease (aHR 1.11, 95%CI 1.03-1.2). Diabetic neuropathy showed a significantly higher risk of stroke development than diabetic kidney disease (aHR 1.17, 95%CI 1.1-1.25) and diabetic retinopathy (aHR 1.12, 95%CI 1.03-1.21). Diabetic retinopathy had a significantly higher risk of incident heart failure than diabetic kidney disease (aHR 1.43, 95%CI 1.3-1.57), and diabetic neuropathy had a significantly lower risk of incident heart failure than diabetic retinopathy (aHR 0.79, 95%CI 0.71-0.87).

CONCLUSIONS

T2D patients with microvascular disease have a significantly higher risk of cardiovascular morbidities and mortality than those without microvascular disease. In the matched cohorts, diabetic neuropathy was significantly associated with stroke development, and diabetic retinopathy had a significant association with heart failure compared to other microvascular diseases.

Prevalence of Diabetic Retinopathy in Indigenous and Non-Indigenous Australians: A Systematic Review and Meta-analysis

TOPIC

This systematic review and meta-analysis summarizes evidence relating to the prevalence of diabetic retinopathy (DR) among Indigenous and non-Indigenous Australians.

CLINICAL RELEVANCE

Indigenous Australians suffer disproportionately from diabetes-related complications. Exploring ethnic variation in disease is important for equitable distribution of resources and may lead to identification of ethnic-specific modifiable risk factors. Existing DR prevalence studies comparing Indigenous and non-Indigenous Australians have shown conflicting results.

METHODS

This study was conducted following Joanna Briggs Institute guidance on systematic reviews of prevalence studies (PROSPERO ID: CRD42022259048). We performed searches of Medline (Ovid), EMBASE, and Web of Science until October 2021, using a strategy designed by an information specialist. We included studies reporting DR prevalence among diabetic patients in Indigenous and non-Indigenous Australian populations. Two independent reviewers performed quality assessments using a 9-item appraisal tool. Meta-analysis and meta-regression were performed using double arcsine transformation and a random-effects model comparing Indigenous and non-Indigenous subgroups.

RESULTS

Fifteen studies with 8219 participants met criteria for inclusion. The Indigenous subgroup scored lower on the appraisal tool than the non-Indigenous subgroup (mean score 50% vs. 72%, P = 0.04). In the unadjusted meta-analysis, DR prevalence in the Indigenous subgroup (30.2%; 95% confidence interval [CI], 24.9-35.7) did not differ significantly (P = 0.17) from the non-Indigenous subgroup (23.7%; 95% CI, 16.8-31.4). After adjusting for age and quality, DR prevalence was higher in the Indigenous subgroup (P < 0.01), with prevalence ratio point estimates ranging from 1.72 to 2.58, depending on the meta-regression model. For the secondary outcomes, prevalence estimates were higher in the Indigenous subgroup for diabetic macular edema (DME) (8.7% vs. 2.7%, P = 0.02) and vision-threatening DR (VTDR) (8.6% vs. 3.0%, P = 0.03) but not for proliferative DR (2.5% vs. 0.8%, P = 0.07).

CONCLUSIONS

Indigenous studies scored lower for methodological quality, raising the possibility that systematic differences in research practices may be leading to underestimation of disease burden. After adjusting for age and quality, we found a higher DR prevalence in the Indigenous subgroup. This contrasts with a previous review that reported the opposite finding of lower DR prevalence using unadjusted pooled estimates. Future epidemiological work exploring DR burden in Indigenous communities should aim to address methodological weaknesses identified by this review.

The association of alanine aminotransferase and diabetic microvascular complications: A Mendelian randomization study

AIMS

Alanine aminotransferase (ALT) is positively related to diabetes risk in observational studies, whereas Mendelian randomization supports a linear causal association. In contrast, the relationship between ALT and diabetic nephropathy, and diabetic retinopathy is counter-intuitive in observational studies. Furthermore, no MR study has examined their causal association. The study aimed to investigate whether genetically determined ALT has a causal effect on diabetic nephropathy and diabetic retinopathy.

METHODS

Genetic instruments associated with ALT (P < 5×10^-8) were obtained from a recent genome-wide association study (GWAS) that included 437,267 individuals of European ancestry. Summary data of diabetic microvascular complications were derived from the FinnGen study (3,283 cases and 181,704 controls for diabetic nephropathy, and 14,584 cases and 176,010 controls for diabetic retinopathy, both were of European ancestry). Effect estimation and pleiotropy testing were performed using inverse variance weighted (IVW), MR-Egger regression, weighted median, and mode-based estimator methods. We additionally performed sensitivity analysis excluding proxy single nucleotide polymorphisms (SNPs) or lowering the GWAS significance threshold (P < 5×10^-7) to test the robustness of the results.

RESULTS

Based on IVW, a 2-fold increase in genetically determined ALT level was positively associated with diabetic nephropathy (odd ratio, [95% confidence interval], 1.73 [1.26-2.37], P = 0.001) and diabetic retinopathy (1.29 [1.08-1.54], P = 0.005), but a null causal association in three pleiotropy robust methods, namely, MR-Egger, weighted median and mode-based estimator. We obtained similar results in the sensitivity analysis of excluding proxy SNPs or lowering the GWAS significance threshold.

CONCLUSIONS

With caution, we concluded that ALT plays no linear causal role in developing both diabetic nephropathy and diabetic retinopathy. Further investigations are required to test the hypothesis of a non-linear causal association.

Digital solution for detection of undiagnosed diabetes using machine learning-based retinal image analysis

INTRODUCTION

Undiagnosed diabetes is a global health issue. Previous studies have estimated that about 24.1%-75.1% of all diabetes cases are undiagnosed, leading to more diabetic complications and inducing huge healthcare costs. Many current methods for diabetes diagnosis rely on metabolic indices and are subject to considerable variability. In contrast, a digital approach based on retinal image represents a stable marker of overall glycemic status.

RESEARCH DESIGN AND METHODS

Our study involves 2221 subjects for developing a classification model, with 945 subjects with diabetes and 1276 controls. The training data included 70% and the testing data 30% of the subjects. All subjects had their retinal images taken using a non-mydriatic fundus camera. Two separate data sets were used for external validation. The Hong Kong testing data contain 734 controls without diabetes and 660 subjects with diabetes, and the UK testing data have 1682 subjects with diabetes.

RESULTS

The 10-fold cross-validation using the support vector machine approach has a sensitivity of 92% and a specificity of 96.2%. The separate testing data from Hong Kong provided a sensitivity of 99.5% and a specificity of 91.1%. For the UK testing data, the sensitivity is 98.0%. The accuracy of the Caucasian retinal images is comparable with that of the Asian data. It implies that the digital method can be applied globally. Those with diabetes complications in both Hong Kong and UK data have a higher probability of risk of diabetes compared with diabetes subjects without complications.

CONCLUSIONS

A digital machine learning-based method to estimate the risk of diabetes based on retinal images has been developed and validated using both Asian and Caucasian data. Retinal image analysis is a fast, convenient, and non-invasive technique for community health applications. In addition, it is an ideal solution for undiagnosed diabetes prescreening.

Linking Cerebrovascular Dysfunction to Age-Related Hearing Loss and Alzheimer’s Disease—Are Systemic Approaches for Diagnosis and Therapy Required?

Alzheimer’s disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction, cognitive decline, and the accumulation of amyloid β peptide (Aβ) in the brain and tau-related lesions in neurons termed neurofibrillary tangles (NFTs). Aβ deposits and NFT formation are the central pathological hallmarks in AD brains, and the majority of AD cases have been shown to exhibit a complex combination of systemic comorbidities. While AD is the foremost common cause of dementia in the elderly, age-related hearing loss (ARHL) is the most predominant sensory deficit in the elderly. During aging, chronic inflammation and resulting endothelial dysfunction have been described and might be key contributors to AD; we discuss an intriguing possible link between inner ear strial microvascular pathology and blood–brain barrier pathology and present ARHL as a potentially modifiable and treatable risk factor for AD development. We present compelling evidence that ARHL might well be seen as an important risk factor in AD development: progressive hearing impairment, leading to social isolation, and its comorbidities, such as frailty, falls, and late-onset depression, link ARHL with cognitive decline and increased risk of dementia, rendering it tempting to speculate that ARHL might be a potential common molecular and pathological trigger for AD. Additionally, one could speculate that amyloid-beta might damage the blood–labyrinth barrier as it does to the blood–brain barrier, leading to ARHL pathology. Finally, there are options for the treatment of ARHL by targeted neurotrophic factor supplementation to the cochlea to improve cognitive outcomes; they can also prevent AD development and AD-related comorbidity in the future.

Diabetic retinopathy as a predictor of cardiovascular morbidity and mortality in subjects with type 2 diabetes

This study aimed to evaluate the predictive value of diabetic retinopathy (DR) and its stages with the incidence of major cardiovascular events and all-cause mortality in type 2 diabetes mellitus (T2DM) persons in our large primary healthcare database from Catalonia (Spain). A retrospective cohort study with pseudo-anonymized routinely collected health data from SIDIAP was conducted from 2008 to 2016. We calculated incidence rates of major cardiovascular events [coronary heart disease (CHD), stroke, or both—macrovascular events] and all-cause mortality for subjects with and without DR and for different stages of DR. The proportional hazards regression analysis was done to assess the probability of occurrence between DR and the study events. About 22,402 T2DM subjects with DR were identified in the database and 196,983 subjects without DR. During the follow-up period among the subjects with DR, we observed the highest incidence of all-cause mortally. In the second place were the macrovascular events among the subjects with DR. In the multivariable analysis, fully adjusted for DR, sex, age, body mass index (BMI), tobacco, duration of T2DM, an antiplatelet or antihypertensive drug, and HbA1c, we observed that subjects with any stage of DR had higher risks for all of the study events, except for stroke. We observed the highest probability of all-cause death events (adjusted hazard ratios, AHRs: 1.34, 95% CI: 1.28; 1.41). In conclusion, our results show that DR is related to CHD, macrovascular events, and all-cause mortality among persons with T2DM.

Age-Related Eye Diseases in Individuals With Mild Cognitive Impairment and Alzheimer's Disease

Introduction

Alzheimer's disease (AD) and age-related eye diseases pose an increasing burden as the world's population ages. However, there is limited understanding on the association of AD/cognitive impairment, no dementia (CIND) with age-related eye diseases.

Methods

In this cross-sectional, memory clinic-based study of multiethnic Asians aged 50 and above, participants were diagnosed as AD (n = 216), cognitive impairment, no dementia (CIND) (n = 252), and no cognitive impairment (NCI) (n = 124) according to internationally accepted criteria. Retinal photographs were graded for the presence of age-related macular degeneration (AMD) and diabetic retinopathy (DR) using standard grading systems. Multivariable-adjusted logistic regression models were used to determine the associations between neurological diagnosis and odds of having eye diseases.

Results

Over half of the adults had at least one eye disease, with AMD being the most common (60.1%; n = 356), followed by DR (8.4%; n = 50). After controlling for age, sex, race, educational level, and marital status, persons with AD were more likely to have moderate DR or worse (OR = 2.95, 95% CI = 1.15–7.60) compared with NCI. In the fully adjusted model, the neurological diagnosis was not associated with AMD (OR = 0.75, 95% CI = 0.45–1.24).

Conclusion

Patients with AD have an increased odds of having moderate DR or worse, which suggests that these vulnerable individuals may benefit from specific social support and screening for eye diseases.

Aloe vera and Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus is defined as prolonged hyperglycemia, which can harm the eyes, kidneys, and cardiovascular and neurological systems. Herbal agents and their derived supplements have been used for treatment of diabetes mellitus as a part of integrated complementary medicine for centuries. Numerous studies have considered Aloe vera (L.) Burm.f, Xanthorrhoeaceae, as an alternative medicine due to its abundant bioactive chemicals, such as alkaloids, anthraquinones, and enthrones, with therapeutical properties including antioxidant, anti-inflammatory, neuro-protective, and anti-diabetic effects. Aloe vera has received considerable attention in traditional medicine for the treatment of several diseases including diabetes mellitus. Numerous studies have investigated the effects of herbal agents on diabetes mellitus using a streptozotocin-induced diabetic model. Thereby, this article reviews the effects of Aloe vera prescription on streptozotocin-induced diabetes mellitus to provide a clear insight into the role of this medicinal plant in several biological functions, such as antioxidant, wound healing, anti-inflammatory, anti-hyperglycemic, and anti-hyperlipidemic in diabetic models.

The role of heart rate variability and heart rate turbulence in diabetic retinopathy

AIMS

The aim of this study was to evaluate the cardiac autonomic functions of individuals with asymptomatic diabetic retinopathy (DR) and no obvious heart disease by heart rate turbulence (HRT) and heart rate variability (HRV) analysis.

METHODS

A total of 72 patients with Type II Diabetes Mellitus: 20 non-retinopathic (NRDM), 26 non-proliferative retinopathic patients (NPDR) and 26 proliferative retinopathic patients (PDR) were enrolled in this cross-sectional study.

RESULTS

The HRV parameters of Standard deviation of NN intervals (SDNN) (119.8±11.7, 101.1±20.2, 100.6±17.04), Standard deviation of the average NN intervals (SDANN) (108.3±10.8, 91.2±17.5, 93.6±18.4), SDNN Index (49.5±5.1, 40.1±13.4, 38.6±12.7), Root mean square of successive RR interval differences (RMSSD) (28.3±5.1, 22.3±7.5, 26±9.2) and Triangular index (34.4±4.3, 29.7±8.8, 27.3±6.7) were significantly lower in the NPDR and PDR groups than in the NRDM group (for all p<0.05). Also, there was a statistically significant higher Turbulence Onset (-1.80±0.7, -1.1±0.9, -0.43±0.81) and lower Turbulence Slope (8.05±2.59, 5.82±3.39, 4.53±2.07) in HRT parameters in patients in the NPDR and PDR groups than in the NRDM group (respectively, NRDM, NPDM, PDM, for all p<0.001).

CONCLUSIONS

We found that HRV and HRT parameters had a significant deterioration in retinopathic individuals compared to the group without retinopathy. We think that HRV and HRT analysis can have an important role in the evaluation of these patients.

Correlation Between Retinopathy and Coronary Microcirculation Dysfunction in Patients with Type 2 Diabetes Mellitus

Purpose

The aim of this study is to evaluate the correlation between retinopathy and coronary microcirculation dysfunction (CMD) in type 2 diabetes mellitus (T2DM) patients.

Methods

198 T2DM patients with left ventricular ejection fraction (LVEF)>50%, no epicardial coronary artery stenosis diagnosis by coronary angiography (CAG) and successfully completed coronary blood flow reserve (CFR) test and laboratory examination were enrolled, and fundus examination was performed on all participants. Two groups were divided according to CFR value, including 86 patients with CMD (CFR≤2.5) in study group and 112 patients without CMD (CFR>2.5) in control group. The composition of various retinopathy in two groups was observed, and the correlation between retinopathy and CMD was analyzed using ordered logistic regression.

Results

There were 13 cases with arteriovenous (A/V) nicking, 4 cases with proliferative diabetic retinopathy (PDR), 14 cases with non-proliferative diabetic retinopathy (NPDR), 17 cases with diabetic retinopathy (DR) with A/V nicking, 38 cases without retinopathy in study group, and 18 cases, 7 cases, 20 cases, 4 cases and 63 cases for each in control group. After adjustment for age, gender, hypertension, diabetes duration, dyslipidemia, glycosylated hemoglobin (HbA1c), body mass index (BMI), A/V nicking, PDR and NPDR, the diference of DR with A/V nicking between study and control group remained statistically signifcant (OR 2.0, 95% CI 0.79 to 3.21, p = 0.001).

Conclusion

DR with A/V nicking could be used as an independent predictor of T2DM patients with CMD. CFR testing should be performed on patients with this kind of eye sign, even if they do not have any symptoms of heart disease. Meanwhile, DR with A/V nicking might be served as a reference indicator of CMD in T2DM patients with chest pain who were unable to be tested for CFR.

The Prevalence and Risk Factors of Diabetic Retinopathy: Screening and Prophylaxis Project in 6 Provinces of China

PURPOSE

To investigate the prevalence and associated factors of diabetic retinopathy (DR) and advanced DR in Chinese adults with diabetes mellitus (DM).

PATIENTS AND METHODS

A cross-sectional study was performed on 4831 diabetic patients from 24 hospitals from April 2018 to July 2020. Non-mydriatic fundus of patients were interpreted by an artificial intelligence (AI) system. Fundus photos that were unsuitable for AI interpretation were interpreted by two ophthalmologists trained by one expert ophthalmologist at Beijing Tongren Hospital. Medical history, height, weight, body mass index (BMI), glycosylated hemoglobin (HbA1c), blood pressure, and laboratory examinations were recorded.

RESULTS

A total of 4831 DM patients were included in this study. The prevalence of DR and advanced DR in the diabetic population was 31.8% and 6.6%, respectively. In multiple logistic regression analysis, male (odds ratio [OR], 1.39), duration of diabetes (OR, 1.05), HbA1c (OR, 1.11), farmer (OR, 1.39), insulin treatment (OR, 1.61), region (northern, OR, 1.78; rural, OR, 6.96), and presence of other diabetic complications (OR: 2.03) were associated with increased odds of DR. The factors associated with increased odds of advanced DR included poor glycemic control (HbA1c >7.0%) (OR, 2.58), insulin treatment (OR, 1.73), longer duration of diabetes (OR, 3.66), rural region (OR, 4.84), and presence of other diabetic complications (OR, 2.36), but overweight (BMI > 25 kg/m²) (OR, 0.61) was associated with reduced odds of advanced DR.

CONCLUSION

This study shows that the prevalence of DR is very high in Chinese adults with DM, highlighting the necessity of early diabetic retinal screening.

Beneficial Effects of Psyllium on the Prevention and Treatment of Cardiometabolic Diseases

Cardiometabolic diseases are reaching epidemic proportions worldwide. Nevertheless, current therapeutic strategies are insufficient; thus, studying novel complementary and alternative medicines remains of the upmost importance. Psyllium has been used for...

Effects of Puerarin on the Prevention and Treatment of Cardiovascular Diseases

Puerarin, an isoflavone glycoside derived from Pueraria lobata (Willd.) Ohwi, has been identified as a pharmacologically active component with diverse benefits. A large number of experimental and clinical studies have demonstrated that puerarin is widely used in the treatment of a variety of diseases. Among them, cardiovascular diseases (CVDs) are the leading cause of death in the world, and therefore remain one of the most prominent global public health concerns. In this review, we systematically analyze the preclinical investigations of puerarin in CVDs, such as atherosclerosis, cardiac hypertrophy, heart failure, diabetic cardiovascular complications, myocardial infarction, stroke and hypertension. In addition, the potential molecular targets of puerarin are also discussed. Furthermore, we summarize the clinical trails of puerarin in the treatment of CVDs. Finally, the therapeutic effects of puerarin derivatives and its drug delivery systems are overviewed.

Association Between the Severity of Diabetic Retinopathy and Optical Coherence Tomography Angiography Metrics

Diabetic retinopathy, the most serious ocular complication of diabetes, imposes a serious economic burden on society. Automatic and objective assessment of vessel changes can effectively manage diabetic retinopathy and prevent blindness. Optical coherence tomography angiography (OCTA) metrics have been confirmed to be used to assess vessel changes. The accuracy and reliability of OCTA metrics are restricted by vessel segmentation methods. In this study, a multi-branch retinal vessel segmentation method is proposed, which is comparable to the segmentation results obtained from the manual segmentation, effectively extracting vessels in low contrast areas and improving the integrity of the extracted vessels. OCTA metrics based on the proposed segmentation method were validated to be reliable for further analysis of the relationship between OCTA metrics and diabetes and the severity of diabetic retinopathy. Changes in vessel morphology are influenced by systemic risk factors. However, there is a lack of analysis of the relationship between OCTA metrics and systemic risk factors. We conducted a cross-sectional study that included 362 eyes of 221 diabetic patients and 1,151 eyes of 587 healthy people. Eight systemic risk factors were confirmed to be closely related to diabetes. After controlling these systemic risk factors, significant OCTA metrics (such as vessel complexity index, vessel diameter index, and mean thickness of retinal nerve fiber layer centered in the macular) were found to be related to diabetic retinopathy and severe diabetic retinopathy. This study provides evidence to support the potential value of OCTA metrics as biomarkers of diabetic retinopathy.

Patient preferences in retinal drug delivery

Retinal vascular diseases (RVDs) are often treated with intravitreally (IVT) injected drugs, with relatively low patient compliance and potential risks. Ongoing research explores alternative RVD treatments, including eye drops and oral tablets. This study surveyed RVD patients treated with IVT injections to establish factors influencing low compliance rates while gauging treatment delivery method preferences. Demographics, perspectives, and treatment preferences were collected via IRB-approved, self-administered survey sent to Glick Eye Institute patients treated via IVT injections. Demographics, diagnoses, and treatments were ascertained from respondents’ medical records. Gender, age, and number of IVT injections received were used as stratifications. Five-level Likert-style scales and t-tests evaluated responses and stratification comparisons. The most common diagnoses in the respondent population (n = 54; response rate = 5%) were age-related macular degeneration, macular edema, and diabetic retinopathy. Respondents had varying levels of education, income, and age. Most (83%) admitted feeling anxious prior to their first IVT injection, but 80% reported willingness to receive IVT injections indefinitely, with a preference for ophthalmologist visits every 1–3 months. Eye drops would be preferred over IVT injections by 76% of respondents, while 65% preferred oral tablets, due to several perceived negative factors of IVT injections and positive factors for eye drops. Stratified groups did not differ in responses to survey questions. RVD patients will accept IVT injections for vision preservation, but alternative delivery methods like eye drops or oral tablets would be preferred. Thus, development of eye drop and oral therapeutics for RVD treatment is further emphasized by these findings.

Impact of type 2 diabetes and microvascular complications on mortality and cardiovascular outcomes in a multiethnic Asian population

INTRODUCTION

Diabetes mellitus is a growing public health epidemic in Asia. We examined the impact of type 2 diabetes, glycemic control and microvascular complications on mortality and cardiovascular outcomes in a multiethnic population-based cohort of Asians without prior cardiovascular disease.

RESEARCH DESIGN AND METHODS

This was a prospective population-based cohort study in Singapore comprising participants from the three major Asian ethnic groups: Chinese, Malays and Indians, with baseline examination in 2004-2011. Participants with type 1 diabetes and those with cardiovascular disease at baseline were excluded. Type 2 diabetes, Hemoglobin A1c (HbA1c) levels and presence of microvascular complications (diabetic retinopathy and nephropathy) were defined at baseline. The primary outcome was all-cause mortality and major adverse cardiovascular events (MACEs), defined as a composite of cardiovascular mortality, myocardial infarction, stroke and revascularization, collected using a national registry.

RESULTS

A total of 8541 subjects were included, of which 1890 had type 2 diabetes at baseline. Subjects were followed for a median of 6.4 (IQR 4.8-8.8) years. Diabetes was a significant predictor of mortality (adjusted HR 1.74, 95% CI 1.45 to 2.08, p<0.001) and MACE (adjusted HR 1.64, 95% CI 1.39 to 1.93, p<0.001). In those with diabetes, higher HbA1c levels were associated with increased MACE rates (adjusted HR (per 1% increase) 1.18, 95% CI 1.11 to 1.26, p<0.001) but not mortality (p=0.115). Subjects with two microvascular complications had significantly higher mortality and MACE compared with those with only either microvascular complication (adjusted p<0.05) and no microvascular complication (adjusted p<0.05).

CONCLUSION

Diabetes is a significant predictor of mortality and cardiovascular morbidity in Asian patients without prior cardiovascular disease. Among patients with type 2 diabetes, poorer glycemic control was associated with increased MACE but not mortality rates. Greater burden of microvascular complications identified a subset of patients with poorer outcomes.