Protective factors for diabetic retinopathy in Type 2 diabetes mellitus patients: Long duration of no less than 10 years

Mendelian randomization analysis reveals a causal effect of Streptococcus salivarius on diabetic retinopathy through regulating host fasting glucose

Diabetic retinopathy (DR) is one of leading causes of vision loss in adults with increasing prevalence worldwide. Increasing evidence has emphasized the importance of gut microbiome in the aetiology and development of DR. However, the causal relationship between gut microbes and DR remains largely unknown. To investigate the causal associations of DR with gut microbes and DR risk factors, we employed two-sample Mendelian Randomization (MR) analyses to estimate the causal effects of 207 gut microbes on DR outcomes. Inputs for MR included Genome-wide Association Study (GWAS) summary statistics of 207 taxa of gut microbes (the Dutch Microbiome Project) and 21 risk factors for DR. The GWAS summary statistics data of DR was from the FinnGen Research Project. Data analysis was performed in May 2023. We identified eight bacterial taxa that exhibited significant causal associations with DR (FDR < 0.05). Among them, genus Collinsella and species Collinsella aerofaciens were associated with increased risk of DR, while the species Bacteroides faecis, Burkholderiales bacterium_1_1_47, Ruminococcus torques, Streptococcus salivarius, genus Burkholderiales_noname and family Burkholderiales_noname showed protective effects against DR. Notably, we found that the causal effect of species Streptococcus salivarius on DR was mediated through the level of host fasting glucose, a well-established risk factor for DR. Our results reveal that specific gut microbes may be causally linked to DR via mediating host metabolic risk factors, highlighting potential novel therapeutic or preventive targets for DR.

Generalized metabolic flux analysis framework provides mechanism-based predictions of ophthalmic complications in type 2 diabetes patients

Chronic metabolic diseases arise from changes in metabolic fluxes through biomolecular pathways and gene networks accumulated over the lifetime of an individual. While clinical and biochemical profiles present just real-time snapshots of the patients' health, efficient computation models of the pathological disturbance of biomolecular processes are required to achieve individualized mechanistic insights into disease progression. Here, we describe the Generalized metabolic flux analysis (GMFA) for addressing this gap. Suitably grouping individual metabolites/fluxes into pools simplifies the analysis of the resulting more coarse-grain network. We also map non-metabolic clinical modalities onto the network with additional edges. Instead of using the time coordinate, the system status (metabolite concentrations and fluxes) is quantified as function of a generalized extent variable (a coordinate in the space of generalized metabolites) that represents the system's coordinate along its evolution path and evaluates the degree of change between any two states on that path. We applied GMFA to analyze Type 2 Diabetes Mellitus (T2DM) patients from two cohorts: EVAS (289 patients from Singapore) and NHANES (517) from the USA. Personalized systems biology models (digital twins) were constructed. We deduced disease dynamics from the individually parameterized metabolic network and predicted the evolution path of the metabolic health state. For each patient, we obtained an individual description of disease dynamics and predict an evolution path of the metabolic health state. Our predictive models achieve an ROC-AUC in the range 0.79-0.95 (sensitivity 80-92%, specificity 62-94%) in identifying phenotypes at the baseline and predicting future development of diabetic retinopathy and cataract progression among T2DM patients within 3 years from the baseline. The GMFA method is a step towards realizing the ultimate goal to develop practical predictive computational models for diagnostics based on systems biology. This tool has potential use in chronic disease management in medical practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13755-023-00218-x.

Visual functional defects in patients with type 2 diabetes mellitus: a questionnaire based cross-sectional study

PURPOSE

To determine the impact of type 2 diabetes mellitus (T2DM) on visual functions, identify different modifiers as risk or protective factors, and find out how these factors affect patients' visual symptoms and visual functions as a whole.

METHODS

We performed an online survey among 1030 participants (400 patients, 630 non-patients). Demographic features and severity of disease were documented, while visual functions were evaluated using National Eye Institute Visual Functioning questionnaire-25 (NEI VFQ-25). Independent t-test, analysis of variance, linear and nonlinear regression models were used to assess all data.

RESULTS

Scores other than color vision among T2DM patients were significantly lower compared with non-T2DM participants. There was significant difference after stratification of age and education, but no significant difference between different genders was observed. Parameters including duration of T2DM, fasting plasma glucose (FPG) and glycosylated hemoglobin A1c (HbA1c) negatively impacted on the scores, with 20 years' of diabetic duration, 10 mmol/L of FPG, 7.5% of HbA1c being potential cut-off points. Poorer best corrected visual acuity (BCVA) and diagnosis of diabetic retinopathy were risk factors, while they simultaneously produced mediation effect, contributing 5%-78% of effect in the deterioration of visual functions caused by longer diabetic duration and higher blood glucose.

CONCLUSION

Significant visual impairments and faster deterioration in visual functions were seen in T2DM patients, with older age, lower educational level, longer diabetic duration, poorer blood glucose administration, limited BCVA, and the presence of diabetic retinopathy identified as risk factors. Average BCVA and diabetic retinopathy also yielded mediation effect as diabetic duration lengthened and blood glucose elevated.

Factors protecting against diabetic retinopathy in a geriatric Indian cohort

Purpose:

Diabetic retinopathy (DR) is a potentially sight-threatening complication of diabetes mellitus. The majority of cases are in older adults. This study aims to evaluate modifiable and nonmodifiable protective factors against DR in a geriatric Indian population.

Methods:

This retrospective observational study uses data from a multitiered ophthalmology network to evaluate several demographic and clinical variables against diabetic retinopathy and visual acuity.

Results:

Our data show that high myopia, the female sex, and no cataract surgery are associated with lower prevalence of DR (OR = 0.21, 0.65, and 0.76, respectively; P < 0.001). We also found that among those with DR, people categorized as payers, retirees, and those living in urban or metropolitan areas have better visual acuity (OR = 0.65, 0.65, 0.83, and 0.73, respectively; P < 0.001). Among those with DR, females, presence of cataracts, and no cataract surgery had lower associations with sight-threatening DR (STDR) (OR = 0.68, 0.37, and 0.76, respectively; P < 0.001). Prevalence of DR decreased in older age groups while controlling for DM duration.

Conclusion:

It is probable that high myopia, the female sex, and better glycemic control are protective against DR and STDR in our study cohort of adults over 60 years of age. It is possible that occupations involving manual labor, delayed cataract surgery, and living past the age of 70 are also protective against DR.

Risk Factors Associated With Diabetic Retinopathy: A Cross-Sectional Study Within Palestinian Patients in Northern West Bank

Risk factors associated with diabetes mellitus (DM) have been widely researched worldwide, but the determinants of these factors among diabetic retinopathy (DR) in Palestine are currently unclear. We aimed to assess the prevalence of DR among DM in Northern West Bank and identify factors associated with DR natural history. Patients with Type 2 diabetes (T2D) (n = 300, age &gt; 18 years) from a main diabetic center covering all northern provinces of Palestine were enrolled to this cross-sectional research. Demographic information including age, sex, and duration of T2D was obtained. Moreover, HbA1C, BMI, hypertension (HTN), controlled T2D, current smoking, and total cholesterol level were assessed. Potential correlations between these factors and DR diagnosed by ophthalmologist were evaluated using different tests on SPSS version 22. Prevalence of DR among our population was 30%; 47.8% of these patients showed mild non-proliferative DR (NPDR), 23.3% moderate NPDR, 16.7% severe NPDR, and 12.2% proliferative DR (PDR). Univariate logistic regression analysis showed age (p = 0.007), HTN (p = 0.022), uncontrolled T2D (p = 0.025), and duration of T2D (&lt;0.001) were mostly associated with DR while multivariate logistic regression showed duration of T2D as the major and solely risk factor for prevalence of DR (p &lt; 0.0001) and were positively correlated with severities of NPDR and being a strong predictor in the PDR (p = 0.001). We identified several important risk factors that affect DR, which could assist to develop effective strategies for metabolic disease prevention among populations in Palestine. Furthermore, our data suggest a necessity to control sugar serum levels and HTN.

Reducing Fall Risks Among Visually Impaired Older Adults

Falls are the leading cause of death due to unintentional injuries in the older adult population, and fall-related death rates among older adults are escalating annually. Visual deficits are underrecognized and underdiagnosed, which increases fall risk. The purpose of this article is to provide a review of the common types of visual impairment, their etiology, and treatment and to present strategies to reduce falls among older adults with visual impairments. Both traditional home safety interventions and emerging technology-based interventions to reduce falls are described. Appropriate use of both traditional and emerging fall prevention interventions may reduce fall risk and falls among older adult home healthcare patients.

Plasma melatonin levels in patients with diabetic retinopathy secondary to type 2 diabetes

BACKGROUND

Melatonin is reported to be related to diabetes mellitus (DM) risk; however, the effect of melatonin on diabetic retinopathy (DR) risk remains unclear.

AIM

The aim of this study was to determine the effect of melatonin on DR risk.

METHODS

A hospital-based case-control study was conducted from January 2020 to June 2020. DR was assessed using the Diabetic Retinopathy preferred practice pattern (PPP)-updated 2019 criteria. The participants were divided into the DM cases without DR (NDR) group, non-proliferative DR (NPDR) group and proliferative DR (PDR) group. Plasma melatonin concentration was detected with the enzyme-linked immunosorbent assay kit. The relationship between plasma melatonin concentration and DR risk as well as severity was assessed.

RESULTS

It was found that plasma melatonin was 72.83 ± 16.25, 60.38 ± 13.43, 44.48 ± 10.30 and 44.69 ± 8.95 pg/mL in healthy controls, NDR group, NPDR and PDR group, respectively. In addition, it was found that plasma melatonin could be used as a potential diagnostic biomarker for DR (AUC = 0.893, P < 0.001). There was a significant positive relationship between total bilirubin and melatonin content (P < 0.001) based on the correlation assay. Significant associations between total bilirubin and melatonin content were also detected in the NPDR (R² = 0.360, P < 0.001) and PDR (R² = 0.183, P < 0.001) groups.

CONCLUSION

The data obtained in this study demonstrated that plasma melatonin concen-tration was decreased in DR cases and could be used as a sensitive and specific marker for the diagnosis of DR. A significant positive relationship between total bilirubin and melatonin was detected. More related studies are required to understand the role of melatonin in DR.

Total Bilirubin Predicts Severe Progression of Diabetic Retinopathy and the Possible Causal Mechanism

Early detection and treatment are key to delaying the progression of diabetic retinopathy (DR), avoiding loss of vision, and reducing the burden of advanced disease. Our study is aimed at determining if total bilirubin has a predictive value for DR progression and exploring the potential mechanism involved in this pathogenesis. A total of 540 patients with nonproliferative diabetic retinopathy (NPDR) were enrolled between July 2014 and September 2016 and assigned into a progression group (N = 67) or a stable group (N = 473) based on the occurrence of diabetic macular edema (DME), vitreous hemorrhage, retinal detachment, or other conditions that may cause severe loss of vision following a telephonic interview in August 2019. After further communication, 108 patients consented to an outpatient consultation between September and November 2019. Our findings suggest the following: (1) TBIL were significant independent predictors of DR progression (HR: 0.70, 95% CI: 0.54-0.89, p = 0.006). (2) Examination of outpatients indicated that compared to stable group patients, progression group patients had more components of urobilinogen and LPS but a lower concentration of TBIL. The relationship between bilirubin and severe DR was statistically significant after adjusting for sex, age, diabetes duration, type of diabetes, FPG, and HbA1c (OR: 0.70, 95% CI: 0.912-0.986, p = 0.016). The addition of serum LPS and/or urobilinogen attenuated this association. This study concludes that total bilirubin predicts an increased risk of severe DR progression. Decreasing bilirubin might be attributed to the increased levels of LPS and urobilinogen, which may indicate that the change of bilirubin levels is secondary to intestinal flora disorder and/or intestinal barrier destruction. Further prospective investigations are necessary to explore the causal associations for flora disorder, intestinal barrier destruction, and DR.