Association of Cognitive Function and Retinal Neural and Vascular Structure in Type 1 Diabetes

Decreased retinal vascular density is associated with cognitive impairment in CADASIL: an optical coherence tomography angiography study

PURPOSE

This study aimed to assess alterations in retinal vascular density in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients using optical coherence tomography angiography (OCTA) and investigate their association with MRI and cognitive features.

METHODS

Twenty-five patients with CADASIL and forty healthy controls were evaluated by Cirrus HD-OCT 5000 with AngioPlex OCTA to determine changes in macular retinal vasculature. Retinal vasculature parameters between two groups were compared. The MRI lesion burden and neuropsychological scales were also examined in patients. The association between OCTA parameters and MRI/cognitive features was evaluated using partial Spearman rank correlation.

RESULTS

The vessel density and perfusion density of whole image in macular region (vessel density: t =  - 2.834, p = 0.005; perfusion density: t =  - 2.691, p = 0.007) were significantly decreased in patients with CADASIL. Moreover, vessel density of whole image in macular region was negatively associated with Fazekas scores (ρ =  - 0.457; p = 0.025) and the number of lacunar infractions (ρ =  - 0.425, p = 0.038) after adjustment for age. Decreased macular vessel density and perfusion density of whole image were also associated with MoCA scores (vessel density: ρ = 0.542, p = 0.006; perfusion density: ρ = 0.478, p = 0.018) and other domain-specific neuropsychological tests (p < 0.05) after adjustment for age.

CONCLUSION

Decreased retinal vascular density was associated with increased MRI lesion burden and cognitive impairment in patients with CADASIL. Our findings suggest that the degree of retinal vascular involvement, as demonstrated by OCTA, may be consistent with the severity of MRI lesions and the degree of cognitive impairment in patients.

CLINICAL CHARACTERIZATION OF AQUEOUS AND VITREOUS RETINOL-BINDING PROTEIN 3 CONCENTRATIONS IN RELATION TO DIABETIC RETINOPATHY SEVERITY, RETINAL STRUCTURES, AND SYSTEMIC COMPLICATIONS

PURPOSE

To evaluate Retinol-Binding Protein 3 (RBP3) from photoreceptors in aqueous and its association with vitreous concentrations, diabetic retinopathy (DR) severity, retinal layer thickness, and clinical characteristics in people with diabetes.

METHODS

RBP3 concentration was measured by custom-developed enzyme-linked immunosorbent assay in aqueous and correlated with vitreous concentrations in patients from the 50-Year Medalist study and Beetham Eye Institute at Joslin Diabetes Center.

RESULTS

Aqueous RBP3 concentration (N = 131) was elevated in eyes with no to mild DR (mean ± SD 0.7 nM ± 0.2) and decreased in eyes with moderate to severe DR (0.65 nM ± 0.3) and proliferative DR (0.5 nM ± 0.2, P < 0.001) compared to eyes without diabetes. Aqueous and vitreous RBP3 concentrations correlated with each other (r = 0.34, P = 0.001) and between fellow eyes (P < 0.0001). History of retinal surgery did not affect aqueous RBP3 concentrations, but cataract surgery affected both vitreous and aqueous levels. Elevated aqueous RBP3 concentration associated with increased thickness of the outer nuclear layer (P = 0.004) and correlated with hemoglobin A1c, whereas vitreous RBP3 concentrations correlated with diabetic systemic complications.

CONCLUSION

These findings suggest that aqueous RBP3 concentration may be an important endogenous clinical retinal protective factor, a biomarker for DR severity, and a promising VEGF-independent clinical intervention target in DR.

Cognitive Performance and Diabetic Retinopathy: What Your Eyes Can Reveal About Your Brain

BACKGROUND

Diabetic retinopathy (DR) is a chronic diabetes complication. People with Type 2 Diabetes Mellitus (T2DM) have two times the risk for dementia, suggesting it is a new chronic diabetes complication.

OBJECTIVE

Evaluate the association of DR with cognitive performance in a T2DM population.

METHODS

Cross-sectional study with 400 T2DM adults from whom socio-demographic, clinical, laboratory data were collected, and screening test for depression symptoms (Patient Health Questionaire- 9 (PHQ-9)), Mini-Mental State Examination (MMSE), Semantic Verbal Fluency Test, Trail Making Test A and B, Word Memory test were performed. All cognitive test scores were converted into Global Cognition z-Score (GCS(z)). The association between GCS(z) < 0 with DR was performed using a multivariate binary logistic regression model adjusted for age ≥ 65 years, school years ≤ 6 years, DM duration ≥ 10 years, depression symptoms score > 9 at PHQ-9, arterial hypertension, physical activity, diabetic retinopathy, macular edema, and cardiovascular disease.

RESULTS

After exclusions, the 251 eligible patients were 56.6% female, with a mean age of 61.1 (±9.8) years, DM duration of 12.6 (±8.9) years, and 7.6 (±4.2) years of school education. DR prevalence was 46.5%. Multivariate Logistic Regression Model showed an association between DR and GCS(z) < 0, with odds ratio (CI95%) of 2.50 (1.18-5.34), adjusted for age, low education level, arterial hypertension and depression symptoms (OD and CI95% respectively: 5.46(2.42-12.34); 12.19 (5.62-26.46); 2.55 (0.88-7.39); 3.53 (1.55-8.07)).

CONCLUSION

In this T2DM population, having DR increased the chance for worse cognitive performance even when adjusted for age, low education level, presence of arterial hypertension, and depression symptoms.

Sulfonylurea for improving neurological features in neonatal diabetes: A systematic review and meta-analyses

OBJECTIVE

In monogenic diabetes due to KCNJ11 and ABCC8 mutations that impair KATP- channel function, sulfonylureas improve long-term glycemic control. Although KATP channels are extensively expressed in the brain, the effect of sulfonylureas on neurological function has varied widely. We evaluated published evidence about potential effects of sulfonylureas on neurological features, especially epilepsy, cognition, motor function and muscular tone, visuo-motor integration, and attention deficits in children and adults with KCNJ11 and ABCC8-related neonatal-onset diabetes mellitus.

RESEARCH DESIGN AND METHODS

We conducted a systematic review and meta-analyses of the literature (PROSPERO, CRD42021254782), including individual-patient data, according to PRISMA, using RevMan software. We also graded the level of evidence.

RESULTS

We selected 34 of 776 publications. The evaluation of global neurological function before and after sulfonylurea (glibenclamide) treatment in 114 patients yielded a risk difference (RD) of 58% (95%CI, 43%-74%; I²  = 54%) overall and 73% (95%CI, 32%-113%; I²  = 0%) in the subgroup younger than 4 years; the level of evidence was moderate and high, respectively. EEG studies of epilepsy showed a RD of 56% (95%CI, 23%-89%; I²  = 34%) in patients with KCNJ11 mutations, with a high quality of evidence. For hypotonia and motor function, the RDs were 90% (95%CI, 69%-111%; I²  = 0%) and 73% (95%CI, 35%-111%; I²  = 0%), respectively, with a high level of evidence.

CONCLUSIONS

Glibenclamide significantly improved neurological abnormalities in patients with neonatal-onset diabetes due to KCNJ11 or ABCC8 mutations. Hypotonia was the symptom that responded best. Earlier treatment initiation was associated with greater benefits.

Elevated Retinol Binding Protein 3 Concentrations Are Associated With Decreased Vitreous Inflammatory Cytokines, VEGF, and Progression of Diabetic Retinopathy

OBJECTIVE

To correlate inflammatory cytokines and vascular endothelial growth factor (VEGF) in vitreous and plasma with vitreous retinol binding protein 3 (RBP3), diabetic retinopathy (DR) severity, and DR worsening in a population with type 1 and type 2 diabetes.

RESEARCH DESIGN AND METHODS

RBP3, VEGF, and inflammatory cytokines were measured in plasma and vitreous samples (n = 205) from subjects of the Joslin Medalist Study and Beetham Eye Institute.

RESULTS

Higher vitreous RBP3 concentrations were associated with less severe DR (P < 0.0001) and a reduced risk of developing proliferative DR (PDR) (P < 0.0001). Higher RBP3 correlated with increased photoreceptor segment thickness and lower vitreous interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and TNF-β (P < 0.05). PDR was associated with lower vitreous interferon-γ and IL-10 and higher VEGF, IL-6, and IL-15 (P < 0.05), but was not associated with their plasma concentrations.

CONCLUSIONS

Higher vitreous RBP3 concentrations are associated with less severe DR and slower rates of progression to PDR, supporting its potential as a biomarker and therapeutic agent for preventing DR worsening, possibly by lowering retinal VEGF and inflammatory cytokines.

Risk factors for cognitive decline in type 2 diabetes mellitus patients in Brazil: a prospective observational study

BACKGROUND

Type 2 Diabetes Mellitus (T2DM) patients are twice as likely to develop dementia. The study's goal was to evaluate cognitive performance and risk factors for cognitive decline in this population.

METHODS

Prospective observational study was conducted with 400 T2DM adults, of whom, during routine baseline and follow-up appointments, had socio-demographic, clinical, and laboratory data collected, and underwent physical examination, screening for depression symptoms (Patient Health Questionaire-9-PHQ-9), and cognitive tests: Mini-Mental State Examination (MMSE), Semantic Verbal Fluency Test, Trail Making Test A/B, and Word Memory Tests. Each cognitive test score was converted to a z-score and its average resulted in a new variable called Global Cognitive z-Score [GCS(z)]. Averages of the cognitive test scores and GCS(z) at both moments were compared by the Student's T-Test for paired samples. Multivariate binary logistic regression models were built to assess the association of GCS(z) < zero with risk factors for cognitive decline at the baseline and follow-up.

RESULTS

After exclusions, 251 patients were eligible, being 56.6% female, mean age of 61.1 (± 9.8) years, 12.6 (± 8.9) years of DM duration, and 7.6 (± 4.2) years of school education. Follow-up had 134 patients reevaluated and took place after a mean of 18.4(± 5.0) months. Eleven (14%) patients with a GCS(z) ≥ 0 at baseline turned into a GCS(z) < 0 at follow-up. There were no significant differences between the means of cognitive test scores and GCS(z) at the two evaluation moments. At the baseline, the multivariate logistic regression model identified five risk factors associated with GCS(z) < zero: age ≥ 65 years, schooling ≤ 6 years, arterial hypertension, depression symptoms, and diabetic retinopathy (DR), with odds ratio (OR) and 95% confidence interval (CI95%) respectively: 5.46 (2.42-12.34); 12.19 (5.62-26.46); 2.55 (0.88-7.39); 3.53 (1.55-8.07) e 2.50 (1.18-5.34). At follow-up, the risk factors for GCS(z) < zero were: schooling ≤ 6 years, DM duration ≥ 10 years, depression symptoms, arterial hypertension, and cardiovascular disease (CVD), OR and CI95% respectively: 10.15 (3.68-28.01); 2.68 (0.96-7.48); 4.92 (1.77-13.70); 7.21 (1.38-35.71) e 5.76 (1.93-17.18).

CONCLUSIONS

Based on our results, cognitive evaluation and follow-up should be incorporated on the routine of T2DM patients, especially for those with advanced age, low education level, prolonged DM duration, arterial hypertension, depression symptoms, CVD, and DR.

Performance Assessment of Two Different Approaches of Measuring Skeletonized Radial Peripapillary Capillary Vessel Density in Glaucoma Patients

Objective

To compare performance assessment of two methods of measuring radial peripapillary capillary (RPC) vessel density (VD) after skeletonization using MATLAB and Image J in glaucoma clinical setting.

Methods

Seventy-three eyes of 73 glaucoma patients from Beijing Tongren Hospital were included in this prospective study. Original images of RPC were obtained using optical coherence tomography angiography. Two approaches were executed before measuring. Method 1 (M1) required image sharpening, removal of big vessels, and skeletonization. Method 2 (M2) required skeletonization and removal of major vessels. Each method was executed twice. Repeatability and correlations with glaucomatous parameters were assessed. Factors associated with retinal nerve fiber layer thickness (RNFLT) and visual field mean deviation (MD) were analyzed.

Results

Average VD was 13.86 ± 2.73 and 7.50 ± 2.50% measured by M1 and M2. Percentage of total elimination of the major vessels was 36.99 and 100% by M1 and M2, respectively. The intrasession and intersession reproducibility was higher by M2 (ICC = 0.979, ICC = 0.990) than by M1 (ICC = 0.930, ICC = 0.934). VD measured by M2 showed stronger correlations with glaucomatous parameters than by M1. By stepwise multiple linear regression, thinner RNFLT was associated with smaller VD measured by M2 (B = 4.643, P < 0.001). Worse MD was associated with smaller VD measured by M1 (B = 1.079, P = 0.015).

Conclusion

The VD measured by M2 showed better reproducibility and higher correlation with glaucomatous structural parameters. Image sharpning helps display of hazy vasculature in glaucoma, which may reflect visual function better. Researchers should carefully choose image processing methods according to their research object.

Retinal Thickness Associates with Cognition Dysfunction in Young Adult with Type 1 Diabetes in Taiwan

BACKGROUND

Several factors could affect the cognitive dysfunction in patients with type 1 diabetes (T1D).

OBJECTIVES

To report the characteristic of cognitive dysfunction in T1D and find its association with the retinal thickness.

SUBJECTS

We recruited one hundred and seven patients with T1D in our study.

METHODS

Detailed clinical and demographic factors and Cambridge Automated Neuropsychological Test Battery (CANTAB) were performed in all participants. The age at onset>5 years old and ≤5 years old groups was defined as old- and young-onset groups. The levels of the average values of 5-year glycated hemoglobin (HbA1c_5) before study were collected. Ophthalmic study and central retinal thickness (CRT) were performed.

RESULTS

The median age of T1D was 24.9 years old and 57 participants were women. The median age at onset was 7.4 years old, and mean disease duration was 17.2 years. After adjusting off multiple covariates by the regression analyses, the young-onset group had significantly a longer latency in sustained attention than old-onset group (P = 0.02). The HbA1c_5 showed a significantly negative association with the sustained attention (P = 0.03). The average values of CRT showed significantly negative correlations with the reaction time in sustained attention and visual searching (P = 0.04 and P < 0.01, respectively).

CONCLUSIONS

Our results suggest that age at onset and glycemic control had significant impacts on different cognitive domains in T1D. The CRT had a significant correlation with sustained attention, which could be a surrogate markers of brain structural changes in T1D.

Meta-analysis of transcriptional regulatory networks for lipid metabolism in neural cells from schizophrenia patients based on an open-source intelligence approach

There have been a number of reports about the transcriptional regulatory networks in schizophrenia. However, most of these studies were based on a specific transcription factor or a single dataset, an approach that is inadequate to understand the diverse etiology and underlying common characteristics of schizophrenia. Here we reconstructed and compared the transcriptional regulatory network for lipid metabolism enzymes using 15 public transcriptome datasets of neural cells from schizophrenia patients. Since many of the well-known schizophrenia-related SNPs are in enhancers, we reconstructed a network including enhancer-dependent regulation and found that 53.3 % of the total number of edges (7,577 pairs) involved regulation via enhancers. By examining multiple datasets, we found common and unique transcriptional modes of regulation. Furthermore, enrichment analysis of SNPs that were connected with genes in the transcriptional regulatory networks by eQTL suggested an association with hematological cell counts and some other traits/diseases, whose relationship to schizophrenia was either not or insufficiently reported in previous studies. Based on these results, we suggest that in future studies on schizophrenia, information on genotype, comorbidities and hematological cell counts should be included, along with the transcriptome, for a more detailed genetic stratification and mechanistic exploration of schizophrenia.

Pathogenic mitochondrial dysfunction and metabolic abnormalities

Herein we trace links between biochemical pathways, pathogenesis, and metabolic diseases to set the stage for new therapeutic advances. Cellular and acellular microorganisms including bacteria and viruses are primary pathogenic drivers that cause disease. Missing from this statement are subcellular compartments, importantly mitochondria, which can be pathogenic by themselves, also serving as key metabolic disease intermediaries. The breakdown of food molecules provides chemical energy to power cellular processes, with mitochondria as powerhouses and ATP as the principal energy carrying molecule. Most animal cell ATP is produced by mitochondrial synthase; its central role in metabolism has been known for >80 years. Metabolic disorders involving many organ systems are prevalent in all age groups. Progressive pathogenic mitochondrial dysfunction is a hallmark of genetic mitochondrial diseases, the most common phenotypic expression of inherited metabolic disorders. Confluent genetic, metabolic, and mitochondrial axes surface in diabetes, heart failure, neurodegenerative disease, and even in the ongoing coronavirus pandemic.

Toward a New Staging System for Diabetic Retinopathy Using Wide Field Swept-Source Optical Coherence Tomography Angiography

PURPOSE OF REVIEW

For over 50 years, diabetic retinopathy (DR) has been classified by pathologic features seen on clinical examination and conventional retinal photographs. However, newer technology such as optical coherence tomography angiography (OCTA) now enables rapid acquisition of retinal structural and vascular information in a reliable, non-invasive, high-resolution fashion. Here, we highlight recent studies that have explored wide field swept-source OCTA (WF SS-OCTA) for the diagnosis and management of DR.

RECENT FINDINGS

Multiple studies have demonstrated the utility of WF SS-OCTA for detection of all clinically relevant features of DR. An updated DR staging system is proposed that leverages the advantages of WF SS-OCTA, including the ability to correlate detailed vascular and structural pathology over time with longitudinal imaging. WF SS-OCTA has tremendous potential for evaluating patients with DR. A new WF SS-OCTA-based staging system may be useful in routine clinical practice and for clinical trials.

Association of Cognitive Function and Retinal Neural and Vascular Structure in Type 1 Diabetes

CONTEXT

Cognitive dysfunction is a growing and understudied public health issue in the aging type 1 diabetic population and is difficult and time-consuming to diagnose. Studies in long duration type 1 diabetes have reported the presence of proliferative diabetic retinopathy was associated with cognitive dysfunction.

OBJECTIVE

This study assessed whether structural and vascular abnormalities of the retina, representing an extension of the central nervous system, are associated with cognitive impairment and other complications of type 1 diabetes.

METHODS

An observational cross-sectional study of individuals with 50 or more years of type 1 diabetes (Joslin Medalist Study) was conducted at a university hospital in the United States. The study included 129 participants with complete cognitive testing. Validated cognitive testing measures included psychomotor speed, and immediate, and delayed memory. Optical coherence tomography (OCT) and OCT angiography (OCTA) were performed to obtain neural retinal layer thicknesses and vascular density for superficial (SCP) and deep retinal capillary plexus (DCP). Multivariable modeling was adjusted for potential confounders associated with outcomes in unadjusted analyses.

RESULTS

Decreased vessel density of the SCP and DCP was associated with worse delayed memory (DCP: P = .002) and dominant hand psychomotor speed (SCP: P = .01). Thinning of the retinal outer nuclear layer was associated with worse psychomotor speed both in nondominant and dominant hands (P = .01 and P = .05, respectively). Outer plexiform layer thickness was associated with delayed memory (P = .04).

CONCLUSION

These findings suggest that noninvasive retinal imaging using OCT and OCTA may assist in estimating the risks for cognitive dysfunction in people with type 1 diabetes.

Retinal Imaging Techniques Based on Machine Learning Models in Recognition and Prediction of Mild Cognitive Impairment

BACKGROUND AND PURPOSE

Mild Cognitive Impairment (MCI) is thought to be the signal of many progressive diseases but is easily ignored. Therefore, a simple and easy screening method for recognizing and predicting MCI is urgently needed. The study aimed to establish machine learning models of retinal vascular features to categorize and predict MCI.

PATIENTS AND METHODS

Subjects enrolled underwent cognitive function assessment and were divided into a normal group, an MCI group, and a dementia group, and fundus photography was performed. MATLAB 2019b was used for fundus image preprocessing and vascular segmentation. Via the Green channel, adaptive histogram equalization (AHE), image binarization, and median filtering, we obtained the original and segmentation retinal vessel images. Afterwards, the histogram of oriented gradient (HOG) was used for image feature extraction. Support vector machine (SVM) and extreme learning machine (ELM) were selected for training models in the fundus original images and fundus vascular segmentation images, respectively. Among the three cognitive groups, sensitivity, specificity, the receiver operating characteristic (ROC) curves, and the area under the curve (AUC) were used to evaluate and compare the predictive performance of the two models in the fundus original and vascular segmentation images, respectively.

RESULTS

A total of 86 eligible subjects were enrolled in the study. After a clinical cognitive assessment, the participants were divided into the normal group (N = 38), the MCI group (N = 26), and the dementia group (N = 22). A total of 332 qualified fundus images were adopted after screening. Comparing the models among the three groups showed that the SVM model had more advantages than the ELM model in the fundus original images and vascular segmentation images. Meanwhile, we found that the original images performed better than the segmentation images in the same prediction model. Among the three groups, the SVM model of the fundus original images had the best performance.

CONCLUSION

The establishment of a predictive model based on vascular-related feature extraction from fundus images has high recognition and prediction abilities for cognitive function and can be used as a screening method for MCI.

CLINICAL TRIAL REGISTRATION

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