Glycemic thresholds for diabetes-specific retinopathy: implications for diagnostic criteria for diabetes

Prediction of proliferative diabetic retinopathy using machine learning in Latino and non-Hispanic black cohorts with routine blood and urine testing

PURPOSE

The objective was to predict proliferative diabetic retinopathy (PDR) in non-Hispanic Black (NHB) and Latino (LA) patients by applying machine learning algorithms to routinely collected blood and urine laboratory results.

METHODS

Electronic medical records of 1124 type 2 diabetes patients treated at the Bronxcare Hospital eye clinic between January and December 2019 were analysed. Data collected included demographic information (ethnicity, age and sex), blood (fasting glucose, haemoglobin A1C [HbA1c] high-density lipoprotein [HDL], low-density lipoprotein [LDL], serum creatinine and estimated glomerular filtration rate [eGFR]) and urine (albumin-to-creatinine ratio [ACR]) test results and the outcome measure of retinopathy status. The efficacy of different machine learning models was assessed and compared. SHapley Additive exPlanations (SHAP) analysis was employed to evaluate the contribution of each feature to the model's predictions.

RESULTS

The balanced random forest model surpassed other models in predicting PDR for both NHB and LA cohorts, achieving an AUC (area under the curve) of 83%. Regarding sex, the model exhibited remarkable performance for the female LA demographic, with an AUC of 87%. The SHAP analysis revealed that PDR-related factors influenced NHB and LA patients differently, with more pronounced disparity between sexes. Furthermore, the optimal cut-off values for these factors showed variations based on sex and ethnicity.

CONCLUSIONS

This study demonstrates the potential of machine learning in identifying individuals at higher risk for PDR by leveraging routine blood and urine test results. It allows clinicians to prioritise at-risk individuals for timely evaluations. Furthermore, the findings emphasise the importance of accounting for both ethnicity and sex when analysing risk factors for PDR in type 2 diabetes individuals.

Overall haemostatic potential assay for prediction of outcomes in venous and arterial thrombosis and thrombo-inflammatory diseases

Thromboembolic diseases including arterial and venous thrombosis are common causes of morbidity and mortality globally. Thrombosis frequently recurs and can also complicate many inflammatory conditions through the process of 'thrombo-inflammation,' as evidenced during the COVID-19 pandemic. Current candidate biomarkers for thrombosis prediction, such as D-dimer, have poor predictive efficacy. This limits our capacity to tailor anticoagulation duration individually and may expose lower risk individuals to undue bleeding risk. Global coagulation assays, such as the Overall Haemostatic Potential (OHP) assay, that investigate fibrin generation and fibrinolysis, may provide a more accurate and functional assessment of hypercoagulability. We present a review of fibrin's critical role as a central modulator of thrombotic risk. The results of our studies demonstrating the OHP assay as a predictive biomarker in venous thromboembolism, chronic renal disease, diabetes mellitus, post-thrombotic syndrome, and COVID-19 are discussed. As a comprehensive and global measurement of fibrin generation and fibrinolytic capacity, the OHP assay may be a valuable addition to future multi-modal predictive tools in thrombosis.

Exploring Family Perspectives on a Group-Based Hands-on Advanced Carbohydrate Counting Education Program for Children and Adolescents with Type 1 Diabetes: A Qualitative Study

The care needs of children and adolescents with type 1 diabetes and their families are frequently approached as if they were identical to those of adults, overlooking the distinct challenges young people may face. It has been stated that children and adolescents often find conventional conversations with diabetes specialists tiresome and unpleasant. The present study focuses on familial experiences of an advanced carbohydrate counting program tailored to children and adolescents. The data encompass semi-structured interviews with families who participated in a group-based child-centered advanced carbohydrate counting program. The analysis revealed five themes: (1) peer-to-peer interaction is an essential determinant of sharing and learning; (2) illness perception significantly influences dietary intake; (3) normalization of diabetes in everyday life eases the disease burden; (4) repetition of dietary knowledge is important for retention; and (5) creating a safe and playful learning environment is crucial to engaging children and adolescents in their own treatment. The present findings suggest that it would be beneficial to explore and consider alternative teaching approaches that are adapted to a more interactive and engaging learning environment that is specifically tailored to children and adolescents. This entails moving away from traditional individual approaches.

HIV and type 2 diabetes: An evolving story

INTRODUCTION

Diabetes is widely reported to be more common in people living with HIV (PLWH). Much of the data supporting this originated during the earlier HIV era. The perceived increased risk of type 2 diabetes is reflected in HIV clinical guidelines that recommend screening for diabetes in PLWH on anti-retroviral therapy (ART). However, international HIV clinical guidelines do not agree on the best marker of glycaemia to screen for diabetes. This stems from studies that suggest HbA1c underestimates glycaemia in PLWH.

METHODS

Within this review we summarise the literature surrounding the association of HIV and type 2 diabetes and how this has changed over time. We also present the evidence on HbA1c discrepancy in PLWH.

CONCLUSION

We suggest there is no basis to any international guidelines to restrict HbA1c based on HIV serostatus. We recommend, using the current evidence, that PLWH should be screened annually for diabetes in keeping with country specific guidance. Finally, we suggest future work to elucidate phenotype and natural history of type 2 diabetes in PLWH across all populations.

Using nephropathy as an outcome to determine the HbA1c diagnostic threshold for type 2 diabetes

OBJECTIVE

The hemoglobin A1c (HbA1c) diagnostic threshold for type 2 diabetes (T2D) of 6.5 % (48 mmol/mol) was based on the prevalence of retinopathy found in populations not known to have T2D. It is unclear if nephropathy has a similar HbA1c threshold, partly because it is a rarer complication of early diabetes. This cohort study investigated a very high diabetes prevalence population to determine if a better diagnostic HbA1c value can be established for predicting nephropathy rather than retinopathy in subjects without T2D.

METHODS

The urine albumin:creatinine ratios (UACRs) of 2920 healthy individuals from the Qatar Biobank who had an HbA1c ≥ 5.6 %. were studied. Nephropathy was defined as a UACR≥30 mg/g and its prediction by HbA1c was assessed using cut-points ranging from 5.7 to 7.0 % to dichotomize high from low HbA1c.

RESULTS

Although there was a significant trend for an increased prevalence of abnormal UACR as the HbA1c threshold increased (p < 0.01), significance was due mostly to subjects with HbA1c ≥ 7.0 % (53 mmol/mol). The odds ratios for abnormal UACR were similar over the 5.7-6.9 % HbA1c threshold range, with a narrow odds ratio range of 1.2-1.6. Utilizing area-under-receiver-operating characteristic curves, no HbA1c threshold <7.0 % was identified as the best predictor of nephropathy.

CONCLUSION

Even in a population with a high prevalence of known and unknown diabetes, no HbA1c threshold <7.0 % could be found predicting an increased prevalence of nephropathy. This means there is not a requirement to change the existing retinopathy-based HbA1c threshold of 6.5 % to also accommodate diabetes nephropathy risk.

Pharmacist-Managed Diabetic Retinopathy in Hispanic/LatinX Population

There are three major microvascular complications of diabetes, retinopathy, nephropathy, and neuropathy, among which diabetic retinopathy (DR) is the most common. Several studies suggest that the Hispanic/LatinX population exhibit the highest cases of both diabetes and DR. Strategies aimed at reducing risk factors that could minimize the likelihood of DR development or progression could be beneficial. This retrospective study assessed DR in the Hispanic/LatinX population in pharmacist-managed cardiovascular risk reduction services. A chart review was conducted for 60 individuals who visited clinics led by both a pharmacist and a primary care physician (intervention group) and 178 individuals who saw physicians only (control group). Demographics, metabolic parameters, DR severity, and pharmacist appointment data were collected. The highest benefit of pharmacist intervention was observed in terms of a greater but insignificant decrease in HbA1c; however, there was no benefit of pharmacist's intervention on DR in general, likely due to the longer duration of diabetes and higher HbA1c at the beginning of the study. When the DR progression was examined based on the frequency of pharmacy visits, individuals who met a pharmacist more than two times per year showed more stable and lesser worsening of DR. Overall, our studies suggest that pharmacist intervention could benefit retinopathy outcome; however, well-known determinants of DR such as good glycemic control and duration of diabetes still play a critical role, in addition to challenges in receiving healthcare by the Hispanic/LatinX population. Future strategies in a prospective manner could help retinopathy outcomes in these at-risk patient populations.

Detection and Intervention: Use of Continuous Glucose Monitoring in the Early Stages of Type 2 Diabetes

The term "prediabetes" has been used to identify the state of abnormal glucose homeostasis (dysglycemia) that often leads to the development of clinical type 2 diabetes. However, this term does not describe the cellular changes that are already taking place in individuals with elevated glucose levels. This article describes our approach to detecting early dysglycemia using continuous glucose monitoring and explains how this approach can be integrated into clinical practice settings.

Mathematical model for assessing glycemic control in type 2 diabetes mellitus

Glycated hemoglobin (HbA1c) and glycated albumin (GA) are vital markers for assessing glucose control in diabetes. This cross-sectional study involving 901 diagnosed type 2 diabetics aimed to compare calculated HbA1c, using the formula HbA1c = 2.6 + 0.03 x FBS (mg/dL), with directly measured HbA1c. Simultaneously, the study assessed the agreement between the two methods through regression analysis and explored correlations with various measures of glycemic control. The non-parametric Kolmogorov-Smirnov test indicated a non-normal data distribution, prompting appropriate statistical tests. Spearman's correlation coefficient revealed a strong correlation of calculated HbA1c, calculated GA, and estimated average glucose with measured parameters. Wilcoxon rank sum test indicated a significant difference between directly measured and calculated HbA1c (Z -9.487033, p < 0.0001). Passing Bablok regression analysis showed a significant deviation from linearity. Despite the potential cost benefits in resource-poor settings, caution is advised regarding interchangeable use of calculated and directly measured HbA1c in clinical decision-making. Data shows the importance of robust analytical methods in glycemic control assessment, offering insights for managing type 2 diabetes mellitus.

LC-MS/MS Analysis of Reaction Products of Arginine/Methylarginines with Methylglyoxal/Glyoxal

Methylglyoxal (MGO) and glyoxal (GO) are toxic α-dicarbonyl compounds that undergo reactions with amine containing molecules such as proteins and amino acids and result in the formation of advanced glycation end products (AGEs). This study aimed at investigating the reactivity of arginine (Arg) or dimethylarginine (SDMA or ADMA) with MGO or GO. The solutions of arginine and MGO or GO were prepared in PBS buffer (pH 7.4) and incubated at 37 °C. Direct electrospray ionization-high-resolution mass spectrometry (ESI-HRMS) analysis of the reaction mixture of Arg and MGO revealed the formation of Arg-MGO (1:1) and Arg-2MGO (1:2) products and their corresponding dehydrated products. Further liquid chromatography (LC)-MS analyses revealed the presence of isomeric products in each 1:1 and 1:2 product. The [M + H]+ of each isomeric product was subjected to MS/MS experiments for structural elucidation. The MS/MS spectra of some of the products showed a distinct structure indicative fragment ions, while others showed similar data. The types of products formed by the arginines with GO were also found to be similar to that of MGO. The importance of the guanidine group in the formation of the AGEs was reflected in similar incubation experiments with ADMA and SDMA. The structures of the products were proposed based on the comparison of the retention times and HRMS and MS/MS data interpretation, and some of them were confirmed by drawing analogy to the data reported in the literature.

Impact of percutaneous coronary intervention on renal function in patients with coronary heart disease

The relationship between cardiac and renal function is complicated. The impact of percutaneous coronary intervention (PCI) on renal function in patients with coronary artery disease is still unclear. The current study sought to assess renal function change, including the time course of renal function, after elective PCI in patients with improved renal function and to identify renal function predictors of major adverse cardiovascular events. We examined data from 1572 CHD patients who had coronary angiography (CAG) or PCI in this retrospective cohort study. Patients receiving elective PCI (n=1240) and CAG (n=332) between January 2013 and December 2018 were included. Pre-PCI and procedural variables associated with post-PCI eGFR, change in renal function after post-PCI follow-up, and post-PCI eGFR association with major adverse cardiovascular events were investigated. Following the procedure, 88.7 percent of PCI group patients had unchanged or improved renal function. The treatment of PCI was found to independently correlate with IRF following coronary angiography in an analysis of patients undergoing PCI [OR 4.561 (95% CI:2 .556-8.139); p<0.001]. The area under the receiver operating characteristic (ROC) curve is 0.763 (model with the treatment of PCI). Improved renal function (IRF) and stable renal function were both associated with a lower risk of a major cardiovascular event.

Prevalence of Retinopathy in Prediabetic Populations: A Systematic Review and Meta-Analysis

Among the leading causes of vision impairment and blindness globally, diabetic retinopathy (DR) is one of the most important causes. There is increasing evidence of DR prevalence in the prediabetic population. This systematic review presents collective data on retinopathy in the prediabetic population. This review article aimed to estimate the reported prevalence of retinopathy in prediabetes, impaired glucose tolerance test (GTT) without diabetes mellitus, and the risk factors involved and to summarize it. Literature searches were done using the Web of Science, CINAHL, Google Scholar, Cochrane, EMBASE, and PubMed databases from inception to April 2023. Our search included the words prediabetes, DR, and risk factors. All searches were looked at for methodological quality and evidence. Thirty-one studies were included after the screening. Population-based data were used in 23 studies (82.1%). The prediabetic population screened was 10,539. The prevalence of retinopathy ranged between 0.3% and 20.9%, showing a median of 8.1% with an interquartile range (IQR) of 4.2-11%, showing great variance in estimates due to the use of different screening methods, methods used for retinopathy grading, and study populations. Several studies compared the population with normal GTT with impaired glucose tolerance (IGT) and inferred that there was a lower prevalence of retinopathy in the normal GTT population (3.0%, IQR 0.3-7.4%) than prediabetes (6.7%, IQR 1.9-10.1%). According to this data, a greater retinopathy prevalence was found in prediabetic populations.

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance.

Mukattash T, Alefishat EA. Glycemic control and its associated factors among diabetic heart failure outpatients at two major hospitals in Jordan

Patients with heart failure (HF) are generally at higher risk of developing type 2 diabetes and having uncontrolled blood glucose. Furthermore, the prevalence of uncontrolled blood glucose in patients with HF is largely unknown. Identifying the factors associated with poor blood glucose control is a preliminary step in the development of effective intervention programs. The current cross-sectional study was conducted at two major hospitals to explore the factors associated with blood glucose control among patients with heart failure and type 2 diabetes. In addition to sociodemographic, medical records were used to collect medical information and a validated questionnaire was used to evaluate medication adherence. Regression analysis showed that poor medication adherence (OR = 0.432; 95%CI 0.204-0.912; P<0.05) and increased white blood cells count (OR = 1.12; 95%CI 1.033-1.213; P<0.01) were associated with poor glycemic control. For enhancing blood glucose control among patients with HF and diabetes, future intervention programs should specifically target patients who have high WBC counts and poor medication.

Screening for Turner syndrome-associated hyperglycemia: Evaluating hemoglobin A1c and fasting blood glucose

INTRODUCTION

Individuals with Turner syndrome (TS) are at increased risk of developing diabetes mellitus (DM). Currently, annual DM screening with hemoglobin A1c (HbA1c) with or without fasting blood glucose (FBG) is recommended starting at age 10. However, the optimal DM screening for individuals with TS is not known. The purpose of this study was to evaluate the correlation between HbA1c, FBG, and the 2-hour oral glucose tolerance test (OGTT). A second goal was to query whether optimal HbA1c and fasting (FBG) cut points for TS-associated DM and impaired glucose tolerance (IGT), as defined by the OGTT 2-hour blood glucose (BG), might differ from those for the general population.

METHODS

Individuals with TS ≥ age 10 from the TS: Genotype Phenotype study in the National Institute of Child Health and Human Development's Data and Specimen Hub (DASH) who had 2-hour OGTT BG, HbA1c, and FBG were included. Correlations between HbA1c, FBG, and 2-hour OGTT BG were evaluated. Areas under the receiver operative characteristic (ROC-AUC) curves were generated. Optimal cut points for predicting TS-associated IGT (2-hour BG ≥ 7.77 mmol/L ) and DM 2-hour BG ≥11.10 mmol/L) were determined.

RESULTS

348 individuals had complete data (2-hour OGTT BG < 7.77 mmol/L, n = 239; TS-associated IGT, n = 79; DM, n = 30). ROC-AUC was poor for HbA1c to predict IGT (0.57, 0.49-0.65) but better for DM (0.81, 0.71-0.90). ROC-AUC was also poor for FBG to predict IGT (0.63, 0.56-0.70) but better for DM (0.85, 0.77-0.93). At a cut point of 38 mmol/mol (5.6%), HbA1c had 67% sensitivity (95% CI: 47-83%) and 86% specificity (95% CI: 82-90%) for identifying TS-associated DM defined by 2-hour OGTT BG.

DISCUSSION/CONCLUSIONS

The correlation of HbA1c and 2-hour OGTT BG are lower in TS than other published studies regarding type 2 DM. HbA1c is fairly specific for DM in TS but lacks sensitivity especially at currently utilized levels. Future research should focus on characterizing individuals with TS whose glycemic status is discordant, as this may provide additional insights into the pathophysiology of glucose metabolism in TS. Longitudinal assessement of glycemia as it relates to micro- and macrovascular complications in individuals with TS will further inform DM screening in this population.

Adjusting the Use of Glucose-Lowering Agents in the Real-World Clinical Management of People with Type 2 Diabetes: A Narrative Review

Despite the availability of new treatment classes, glycaemic control in patients with diabetes remains suboptimal globally. The latter is associated with high risk of premature mortality related to diabetes and its microvascular and macrovascular complications. Practice guidelines typically focus on glycated haemoglobin < 7.0% as a therapeutic goal in type 2 diabetes (T2D). Reducing glycated haemoglobin has been proven to reduce the risk of these complications while early attainment of glycaemic goal can have a legacy effect in later life. Both glucocentric and cardiorenal-centric treatment strategies have complementary effects in reducing the trajectory of cardiorenal diseases. In real-word settings, implementation of practice guidelines developed in the USA and Europe may not be applicable to regions such as Asia, where differences in epidemiology, patient phenotypes, cultures, resource availability, and treatment affordability are important considerations. In the present review, we discuss the need to use a pragmatic, albeit evidence-based approach, to combine glucocentric and cardiorenal risk reduction strategies to improve the outcomes in patients with T2D, with particular relevance to Asia Pacific.

Multimodal testing reveals subclinical neurovascular dysfunction in prediabetes, challenging the diagnostic threshold of diabetes

AIM

To explore if novel non-invasive diagnostic technologies identify early small nerve fibre and retinal neurovascular pathology in prediabetes.

METHODS

Participants with normoglycaemia, prediabetes or type 2 diabetes underwent an exploratory cross-sectional analysis with optical coherence tomography angiography (OCT-A), handheld electroretinography (ERG), corneal confocal microscopy (CCM) and evaluation of electrochemical skin conductance (ESC).

RESULTS

Seventy-five participants with normoglycaemia (n = 20), prediabetes (n = 29) and type 2 diabetes (n = 26) were studied. Compared with normoglycaemia, mean peak ERG amplitudes of retinal responses at low (16-Td·s: 4.05 μV, 95% confidence interval [95% CI] 0.96-7.13) and high (32-Td·s: 5·20 μV, 95% CI 1.54-8.86) retinal illuminance were lower in prediabetes, as were OCT-A parafoveal vessel densities in superficial (0.051 pixels/mm² , 95% CI 0.005-0.095) and deep (0.048 pixels/mm² , 95% CI 0.003-0.093) retinal layers. There were no differences in CCM or ESC measurements between these two groups. Correlations between HbA_1c and peak ERG amplitude at 32-Td·s (r = -0.256, p = 0.028), implicit time at 32-Td·s (r = 0.422, p < 0.001) and 16-Td·s (r = 0.327, p = 0.005), OCT parafoveal vessel density in the superficial (r = -0.238, p = 0.049) and deep (r = -0.3, p = 0.017) retinal layers, corneal nerve fibre length (CNFL) (r = -0.293, p = 0.017), and ESC-hands (r = -0.244, p = 0.035) were observed. HOMA-IR was a predictor of CNFD (β = -0.94, 95% CI -1.66 to -0.21, p = 0.012) and CNBD (β = -5.02, 95% CI -10.01 to -0.05, p = 0.048).

CONCLUSIONS

The glucose threshold for the diagnosis of diabetes is based on emergent retinopathy on fundus examination. We show that both abnormal retinal neurovascular structure (OCT-A) and function (ERG) may precede retinopathy in prediabetes, which require confirmation in larger, adequately powered studies.

Ethnic Variation in Diabetic Retinopathy Lesion Distribution on Ultra-widefield Imaging

PURPOSE

To evaluate whether the distribution of diabetic retinopathy (DR) lesions differs among various ethnicities.

DESIGN

Multi-center, retrospective cohort study.

METHODS

We accrued a cohort of 226 eyes with DR consisting of 51 East Asian eyes, 102 South Asian eyes, 30 Caucasian eyes, and 43 Latino eyes, all evaluated with ultrawide field pseudocolor images. Images were manually annotated for DR lesions and were classified as having predominantly peripheral lesions (PPL) or predominantly central lesions (PCL) using 4 quantitative methods. The percent distribution of PCL to PPL was compared among different ethnicities.

RESULTS

Using a single-field lesion frequency-based method, East Asian eyes more frequently demonstrated a PPL distribution (86.3%), whereas South Asian eyes more frequently demonstrated a PCL distribution (64.7%). These findings were also observed when considering only the subset of treatment-naïve eyes. Furthermore, in treatment-naïve eyes without proliferative DR, the percent distribution of PPL to PCL in East Asian eyes was significantly different when compared to other ethnicities (P < .0001 South Asian, P = .035 Caucasian, P = .0003 Latino). The majority of patients (60%-78%) in all ethnic groups had moderate nonproliferative diabetic retinopathy(NPDR), and the same difference between East Asian and South Asian eyes was observed in this subgroup.

CONCLUSIONS

The distribution of DR lesions appears to vary among different ethnicities. DR lesions tend to be distributed more peripherally in East Asian eyes compared to other ethnic groups, particularly South Asian eyes, which tend to have more central disease. The prognostic implications of these ethnic differences in DR lesion distribution require further investigation.

Nailfold capillaroscopy and deep learning in diabetes

OBJECTIVE

To determine whether nailfold capillary images, acquired using video capillaroscopy, can provide diagnostic information about diabetes and its complications.

RESEARCH DESIGN AND METHODS

Nailfold video capillaroscopy was performed in 120 adult patients with and without type 1 or type 2 diabetes, and with and without cardiovascular disease. Nailfold images were analyzed using convolutional neural networks, a deep learning technique. Cross-validation was used to develop and test the ability of models to predict five5 prespecified states (diabetes, high glycosylated hemoglobin, cardiovascular event, retinopathy, albuminuria, and hypertension). The performance of each model for a particular state was assessed by estimating areas under the receiver operating characteristics curves (AUROC) and precision recall curves (AUPR).

RESULTS

A total of 5236 nailfold images were acquired from 120 participants (mean 44 images per participant) and were all available for analysis. Models were able to accurately identify the presence of diabetes, with AUROC 0.84 (95% confidence interval [CI] 0.76, 0.91) and AUPR 0.84 (95% CI 0.78, 0.93), respectively. Models were also able to predict a history of cardiovascular events in patients with diabetes, with AUROC 0.65 (95% CI 0.51, 0.78) and AUPR 0.72 (95% CI 0.62, 0.88) respectively.

CONCLUSIONS

This proof-of-concept study demonstrates the potential of machine learning for identifying people with microvascular capillary changes from diabetes based on nailfold images, and for possibly identifying those most likely to have diabetes-related complications.

Assessment of factors affecting flicker ERGs recorded with RETeval from data obtained from health checkup screening

PURPOSE

To determine the factors significantly associated with the amplitudes and implicit times of the flicker electroretinograms (ERGs) recorded with the RETeval system by analyzing the comprehensive data obtained during a health checkup screening.

METHODS

Flicker ERGs were recorded with the RETeval system from 373 individuals who had a normal fundus and optical coherence tomography images. The sex, age, anthropometric, ophthalmologic, and hematologic data were collected from all participants who were 40- to 89-years-of-age. Univariable and multivariable linear mixed effects regression analyses were performed to identify factors that were significantly associated with the implicit times and amplitudes of the RETeval flicker ERGs.

RESULTS

Univariable linear mixed effects regression analysis showed significant correlations between the implicit times and the best-corrected visual acuity, the age, the axial length, the blood sugar level, and the blood urea nitrogen level. Analyses by multivariable linear mixed effects regression identified that the axial length (β = 0.28), the age (β = 0.24), and the blood sugar level (β = 0.092) were three independent factors that were significantly correlated with the implicit times of the RETeval flicker ERGs. Univariable linear mixed effects regression analysis also showed significant correlations between the amplitudes of the RETeval flicker ERGs and the age, the platelet count, and the creatinine level. Multivariable linear mixed effects regression models identified the age (β = -0.092), the platelet count (β = 0.099), and the creatinine level (β = -0.12) as three independent factors that were significantly correlated with the amplitudes of the RETeval flicker ERGs. However, the smoking habits, body mass index, and the blood pressure were not significantly correlated with either the implicit times or amplitudes of the RETeval flicker ERGs.

CONCLUSIONS

Our results indicate that the age and some ophthalmologic and hematologic findings but not the anthropometric findings were significantly associated with the implicit times and amplitudes of the RETeval flicker ERGs. Thus, clinicians should remember these factors when analyzing the RETeval flicker ERGs.

Deciphering the Role of miR-200c-3p in Type 1 Diabetes (Subclinical Cardiovascular Disease) and Its Correlation with Inflammation and Vascular Health

Uncomplicated type 1 diabetes (T1DM) displays all features of subclinical cardiovascular disease (CVD) as is associated with inflammation, endothelial dysfunction and low endothelial progenitor cells. MiR-200c-3p has been shown in animal tissues to be pro-atherogenic. We aimed to explore the role of miR-200c-3p in T1DM, a model of subclinical CVD. 19 samples from T1DM patients and 20 from matched controls (HC) were analyzed. MiR-200c in plasma and peripheral blood mononuclear cells (PBMCs) was measured by real-time quantitative polymerase chain reaction. The results were compared with the following indices of vascular health: circulating endothelial progenitor cells, (CD45dimCD34+VEGFR-2+ or CD45dimCD34+CD133+) and proangiogenic cells (PACs). MiR-200c-3p was significantly downregulated in PBMCs but not in plasma in T1DM. There was a significant negative correlation between the expression of miR-200c-3p and HbA1c, interleukin-7 (IL-7), vascular endothelial growth factor-C (VEGF-C), and soluble vascular cell adhesion molecule-1, and a positive correlation with CD45dimCD34+VEGFR-2+, CD45dimCD34+CD133+ and PACs. Receiver operating curve analyses showed miR-200c-3p as a biomarker for T1DM with significant downregulation of miR-200c-3p, possibly defining subclinical CVD at HbA1c > 44.8 mmol/mol (6.2%). In conclusion, downregulated miR-200c-3p in T1DM correlated with diabetic control, VEGF signaling, inflammation, vascular health and targeting VEGF signaling, and may define subclinical CVD. Further prospective studies are necessary to validate our findings in a larger group of patients.

Risk Factors for the Development of Retinopathy in Prediabetes and Type 2 Diabetes: The Diabetes Prevention Program Experience

OBJECTIVE

To determine glycemic and nonglycemic risk factors that contribute to the presence of diabetic retinopathy (DR) before and after the onset of type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

During the Diabetes Prevention Program (DPP) and DPP Outcome Study (DPPOS), we performed fundus photography over time in adults at high risk for developing T2D, including after they developed diabetes. Fundus photographs were graded using the Early Treatment Diabetic Retinopathy Study (ETDRS) grading system, with DR defined as typical lesions of DR (microaneurysms, exudates, hemorrhage, or worse) in either eye.

RESULTS

By DPPOS year 16 (∼20 years after random assignment into DPP), 24% of 1,614 participants who had developed T2D and 14% of 885 who remained without diabetes had DR. In univariate analyses, using results from across the entire duration of follow-up, American Indian race was associated with less frequent DR compared with non-Hispanic White (NHW) race, and higher HbA1c, fasting and 2-h plasma glucose levels during an oral glucose tolerance test, weight, and history of hypertension, dyslipidemia, and smoking, but not treatment group assignment, were associated with more frequent DR. On multivariate analysis, American Indian race was associated with less DR compared with NHW (odds ratio [OR] 0.36, 95% CI 0.20-0.66), and average HbA1c was associated with more DR (OR 1.92, 95% CI 1.46-1.74 per SD [0.7%] increase in HbA1c).

CONCLUSIONS

DR may occur in adults with prediabetes and early in the course of T2D. HbA1c was an important risk factor for the development of DR across the entire glycemic range from prediabetes to T2D.

Comparison of Short-Term Surgical Outcomes According to Immediately Postoperative Serum Glucose Level in Non-Diabetic Pancreatic Resection Patients

The adequate regulation of postoperative serum glucose level (SGL) is widely accepted; however, the effects for non-diabetic patients who underwent major pancreatic surgery have not yet been established. We discerned the relevance of the immediately postoperative SGL to short-term postoperative outcomes from major pancreatic surgery in non-diabetic patients. Between January 2007 and December 2016, 2259 non-diabetic patients underwent major pancreatic surgery at four tertiary medical centers in Republic of Korea. Based on a SGL of 200 mg/dL, patients were classified into two groups by averaging the results of four SGL tests taken on the first day after surgery, and their short-term postoperative outcomes were analyzed. A 1:1 propensity score matching method was conducted to establish the high SGL group (n = 568) and the normal SGL group (n = 568). The high SGL group experienced a significantly higher rate of level C complications in the Clavien-Dindo classification (CDc) than the normal SGL group (24.1% vs. 16.5%, p = 0.002). Additionally, an SGL of more than 200 mg/dL was associated with a significantly high risk of complications above level C CDc after adjusting for other risk factors (hazard ratio = 1.324, 95% confidence interval = 1.048–1.672, p = 0.019). The regulation of SGL of less than 200 mg/dL in non-diabetic patients early after major pancreatic surgery could be helpful for reducing postoperative complications.

High prevalence and significant ethnic differences in actionable HbA1C after gestational diabetes mellitus in women living in Norway

BACKGROUND

The type 2 diabetes risk after gestational diabetes mellitus (GDM) is twice as high in South Asian compared to European women. Current guidelines differ regarding which test to use as a screening-tool post-GDM. We aimed to identify ethnic differences in the prevalence rates and early predictors for actionable HbA_1c (defined as prediabetes and diabetes) short time after GDM.

METHODS

This cross-sectional study, enrolling South Asian and Nordic women 1-3 years after a diagnosis of GDM, was undertaken at three hospitals in Norway. We performed a clinical and laboratory evaluation including an oral glucose tolerance test (OGTT). Medical records were used to retrieve data during pregnancy. Prediabetes was classified with HbA_1c alone or combined with OGTT glucose measurements according to the WHO, WHO-IEC, and ADA criteria (fasting plasma glucose (FPG) 6.1-6.9 mmol/L, FPG 6.1-6.9 mmol/L and/or HbA_1c 42-47 mmol/mol (6.0-6.4%), and FPG 5.6-6.9 mmol/L and/or HbA_1c 39-47 mmol/mol (5.7-6.4%)). Ethnic differences in prevalence and predictors of glucose deterioration were assed by χ² (Pearson) tests and logistic regression models.

RESULTS

We included 163 South Asian and 108 Nordic women. Actionable HbA_1c levels were highly prevalent and more so among South Asian than Nordic women (WHO-IEC-HbA_1c: 25.8% vs. 6.5% (p ≤ 0.001), ADA-HbA_1c: 58.3% vs. 22.2% (p ≤ 0.001)). Although adding OGTT-data gave higher combined prevalence rates of prediabetes and diabetes (WHO: 65.6% vs. 47.2% (p ≤ 0.05), WHO-IEC: 70.6% vs. 47.2% (p ≤ 0.001), ADA: 87.8% vs. 65.7% (p ≤ 0.001)), the excess risk in the South Asian women was best captured by the HbA_1c. Important predictors for glucose deterioration after GDM were: South Asian ethnicity, GDM before the index pregnancy, use of glucose-lowering drugs in pregnancy, higher age, and higher in-pregnancy fasting glucose levels.

CONCLUSIONS

In women with GDM 1-3 year previously, we found high prevalence and significant ethnic differences in actionable ADA-HbA_1c levels, with South Asian ethnicity, GDM before the index pregnancy, and the use of glucose-lowering drugs in pregnancy as the most important risk factors. This study reinforces the importance of annual screening-preferably with HbA_1c measurements-to facilitate early intervention after GDM.

Glucose tolerance and markers of myocardial injury after an acute coronary syndrome: predictive role of the 1-h plus 2-h plasma glucose at the oral glucose tolerance test

Objective

Impaired glucose tolerance (IGT) has been related to adverse cardiovascular outcomes. We investigated the added value of 1-h plasma glucose (PG) at the oral glucose tolerance test (OGTT) in predicting admission and peak cardiac high-sensitivity troponin T (hs-TnT) and NT-proBNP values in IGT patients admitted for an acute coronary syndrome (ACS).

Research design and methods

Among 192 consecutive ACS patients, 109 had Hb1Ac and fasting plasma glucose negative for newly diagnosed diabetes. Upon OGTT performed > 96 h after admission, 88, conventionally diagnosed as IGT, were divided into: “full glucose tolerance” (1-h PG-OGTT < 155 mg/dL and 2-h PG-OGTT < 140 mg/dL, N = 12);”early IGT” (1 h-PG-OGTT ≥ 155 mg/dL and 2-h PG-OGTT < 140 mg/dL, N = 33);”late IGT” (1-h PG-OGTT < 155 mg/dL and 2-h PG-OGTT ≥ 140 mg/dL, N = 8); and “full IGT” (1-h PG-OGTT ≥ 155 mg/dL and 2-h PG-OGTT ≥ 140 mg/dL, N = 35). The 4 groups were compared for cardiac markers.

Results

The first three groups had similar cardiac marker values, but only full IGT patients had significantly higher admission hs-TnT compared with the 3 other groups [median (interquartile range): 911 (245-2976) vs 292 (46-1131), P < 0.001]. Full IGT patients also had higher hs-TnT peak compared with fully glucose tolerant and early IGT patients. Only full IGT patients had longer hospitalization and higher NT-proBNP vs fully glucose tolerant patients (P = 0.005).

Conclusions

Among non-diabetic ACS patients, only those with both 1-h PG ≥ 155 mg/dL and 2-h PG ≥ 140 mg/dL had more severe myocardial injury and longer hospitalization. One-h PG-OGTT importantly contributes to assessing post-ACS cardiac risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01590-w.

The Correlation of Prediabetes and Type 2 Diabetes With Adiposity in Adults

Background

Fat metabolism is associated with prediabetes and type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the detailed correlation of diabetes status with adiposity among adults.

Methods

Briefly, 28,429 adults aged ≥18 years from both sexes in the National Health and Nutrition Examination Survey (NHANES) 1999–2018 were included in this study. Multivariable linear regression models were used to examine associations of prediabetes and diabetes status, disease duration of T2DM, serum glucose, glycohemoglobin (HbA1c) with total percent fat (TPF), and fat mass distribution.

Results

After adjusting for sociodemographic covariates, health behaviors, hypertension, hypercholesterolemia, there were direct associations of prediabetes and T2DM status with TPF, trunk fat mass, android fat mass, gynoid fat mass and android to gynoid ratio compared with non-diabetes. But the fat mass decreased with the increase of the disease duration in patients with T2DM. Besides, when stratifying by diabetes status, we found direct associations of serum glucose and HbA1c with TPF, trunk fat mass, android fat mass, gynoid fat mass, and android to gynoid ratio in non-diabetic and prediabetic participants. But in patients with T2DM, inverse associations of serum glucose and HbA1c with fat mass were observed.

Conclusions

This study indicated that adults with prediabetes and T2DM had significantly higher TPF, trunk fat mass, android fat mass, gynoid fat mass, and android to gynoid ratio compared with those without diabetes. Moreover, fat mass decreased as the disease duration increased in patients with T2DM. The associations of serum glucose and HbA1c with TPF and fat mass distribution in patients with T2DM were opposite to the relationships observed in non-diabetic and prediabetic participants.

The diagnostic accuracy of HbA1c , compared to the oral glucose tolerance test, for screening for type 2 diabetes mellitus in Africa-A systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of glycated haemoglobin A_1c (HbA_1c ), compared to fasting plasma glucose (FPG) and the oral glucose tolerance test (OGTT), in screening for type 2 diabetes (T2D) in Africa.

METHODS

We systematically searched databases for studies that compared the HbA_1c to either the OGTT, or the FPG for T2D diagnosis were included. The QUADAS 2 tool was used for assessing the quality of included studies. We used the split component synthesis (SCS) method for the meta-analysis of diagnostic accuracy studies to pool the studies for meta-analysis of sensitivity and specificity, primarily at the HbA_1c ≥48 mmol/mol (6.5%) cut-off and at other cut-offs. We assessed heterogeneity using the I²  statistic and publication bias using Doi plots.

RESULTS

Eleven studies, from seven African countries, with 12,925 participants, were included. Against the OGTT, HbA_1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 57.7% (95% confidence interval [CI] 43.4-70.9) and specificity of 92.3% (95% CI 83.9-96.5). Against the FPG, HbA_1c ≥48 mmol/mol (6.5%) had a pooled sensitivity of 64.5% (95% CI 50.5-76.4) and specificity of 94.3% (95% CI 87.9-97.5). The highest sensitivity for HbA_1c , against the OGTT, was at the 42 mmol/mol (6.0%) cut-off.

CONCLUSION

In Africa, the HbA_1c ≥48 mmol/mol (6.5%) cut-off may miss almost half of the individuals with T2D based on blood glucose measures.

Prediabetes and risk of mortality, diabetes-related complications and comorbidities: umbrella review of meta-analyses of prospective studies

AIMS/HYPOTHESIS

The term prediabetes is used for individuals who have impaired glucose metabolism whose glucose or HbA_1c levels are not yet high enough to be diagnosed as diabetes. Prediabetes may already be associated with an increased risk of chronic 'diabetes-related' complications. This umbrella review aimed to provide a systematic overview of the available evidence from meta-analyses of prospective observational studies on the associations between prediabetes and incident diabetes-related complications in adults and to evaluate their strength and certainty.

METHODS

For this umbrella review, systematic reviews with meta-analyses reporting summary risk estimates for the associations between prediabetes (based on fasting or 2 h postload glucose or on HbA_1c) and incidence of diabetes-related complications, comorbidities and mortality risk were included. PubMed, Web of Science, the Cochrane Library and Epistemonikos were searched up to 17 June 2021. Summary risk estimates were recalculated using a random effects model. The certainty of evidence was evaluated by applying the GRADE tool. This study is registered with PROSPERO, CRD42020153227.

RESULTS

Ninety-five meta-analyses from 16 publications were identified. In the general population, prediabetes was associated with a 6-101% increased risk for all-cause mortality and the incidence of cardiovascular outcomes, CHD, stroke, heart failure, atrial fibrillation and chronic kidney disease, as well as total cancer, total liver cancer, hepatocellular carcinoma, breast cancer and all-cause dementia with moderate certainty of evidence. No associations between prediabetes and incident depressive symptoms and cognitive impairment were observed (with low or very low certainty of evidence). The association with all-cause mortality was stronger for prediabetes defined by impaired glucose tolerance than for prediabetes defined by HbA_1c.

CONCLUSIONS/INTERPRETATION

Prediabetes was positively associated with risk of all-cause mortality and the incidence of cardiovascular outcomes, CHD, stroke, chronic kidney disease, cancer and dementia. Further high-quality studies, particularly on HbA_1c-defined prediabetes and other relevant health outcomes (e. g. neuropathy) are required to support the evidence.

Effects of Resistant Starch Interventions on Metabolic Biomarkers in Pre-Diabetes and Diabetes Adults

Simple lifestyle changes can prevent or delay the onset of type 2 diabetes mellitus (T2DM). In addition to maintaining a physically active way of life, the diet has become one of the bases in managing TD2M. Due to many studies linking the ability of resistant starch (RS) to a substantial role in enhancing the nutritional quality of food and disease prevention, the challenge of incorporating RS into the diet and increasing its intake remains. Therefore, we conducted this review to assess the potential benefits of RS on metabolic biomarkers in pre-diabetes and diabetes adults based on available intervention studies over the last decade. Based on the conducted review, we observed that RS intake correlates directly to minimize possible effects through different mechanisms for better control of pre-diabetic and diabetic conditions. In most studies, significant changes were evident in the postprandial glucose and insulin incremental area under the curve (iAUC). Comparative evaluation of RS consumption and control groups also showed differences with inflammatory markers such as TNF-α, IL-1β, MCP-1, and E-selectin. Only RS2 and RS3 were extensively investigated and widely reported among the five reported RS types. However, a proper comparison and conclusion are deemed inappropriate considering the variations observed with the study duration, sample size, subjects and their metabolic conditions, intervention doses, and the intervention base products. In conclusion, this result provides interesting insights into the potential use of RS as part of a sustainable diet in diabetes management and should be further explored in terms of the mechanism involved.

Predictive model and risk analysis for diabetic retinopathy using machine learning: a retrospective cohort study in China

OBJECTIVE

Aiming to investigate diabetic retinopathy (DR) risk factors and predictive models by machine learning using a large sample dataset.

DESIGN

Retrospective study based on a large sample and a high dimensional database.

SETTING

A Chinese central tertiary hospital in Beijing.

PARTICIPANTS

Information on 32 452 inpatients with type-2 diabetes mellitus (T2DM) were retrieved from the electronic medical record system from 1 January 2013 to 31 December 2017.

METHODS

Sixty variables (including demography information, physical and laboratory measurements, system diseases and insulin treatments) were retained for baseline analysis. The optimal 17 variables were selected by recursive feature elimination. The prediction model was built based on XGBoost algorithm, and it was compared with three other popular machine learning techniques: logistic regression, random forest and support vector machine. In order to explain the results of XGBoost model more visually, the Shapley Additive exPlanation (SHAP) method was used.

RESULTS

DR occurred in 2038 (6.28%) T2DM patients. The XGBoost model was identified as the best prediction model with the highest AUC (area under the curve value, 0.90) and showed that an HbA1c value greater than 8%, nephropathy, a serum creatinine value greater than 100 µmol/L, insulin treatment and diabetic lower extremity arterial disease were associated with an increased risk of DR. A patient's age over 65 was associated with a decreased risk of DR.

CONCLUSIONS

With better comprehensive performance, XGBoost model had high reliability to assess risk indicators of DR. The most critical risk factors of DR and the cut-off of risk factors can be found by SHAP method to render the output of the XGBoost model clinically interpretable.

One-hour post-load hyperglycemia combined with HbA1c identifies individuals with augmented duodenal levels of sodium/glucose co-transporter 1

AIMS

Individuals with HbA1c-defined prediabetes (HbA1c 5.7-6.4%) and 1-hour post-load plasma glucose (1hPG) ≥ 155 mg/dl have an increased risk to develop type 2 diabetes (T2DM). T2DM is associated with a higher intestinal expression of sodium/glucose co-transporter 1 (SGLT-1) and glucose transporter 2 (GLUT-2). It is currently unsettled whether HbA1c-defined dysglycemic conditions combined to 1hPG ≥ 155 mg/dl are associated with changes in SGLT-1 and GLUT-2 duodenal abundance.

METHODS

SGLT-1 and GLUT-2 protein levels were assessed by western blot on duodenal mucosa biopsies of 57 individuals underwent an upper gastrointestinal endoscopy.

RESULTS

Compared with the normal group (HbA1c < 5.7%), individuals with HbA1c-defined pre-diabetes and diabetes exhibit no significant change in duodenal SGLT-1 abundance. Conversely, duodenal GLUT-2 levels were progressively increased in subjects with prediabetes and diabetes. Stratifying participants according to HbA1c and 1hPG we found that amongst subjects with HbA1c-defined normal or prediabetes condition those having 1hPG ≥ 155 mg/dl displayed higher duodenal levels of SGLT-1 as compared to their counterparts with 1hPG < 155 mg/dl; in contrast to GLUT-2 levels, which were similar between normal and with prediabetes subjects, regardless of 1hPG value.

CONCLUSION

A value of 1hPG ≥ 155 mg/dl may identify a subset of individuals within HbA1c-defined glycemic categories having a higher duodenal abundance of SGLT-1.

Severity of diabetic retinopathy and its relationship with age at onset of diabetes mellitus in India: A multicentric study

Purpose:

To present clinical profile and risk factors of sight-threatening diabetic retinopathy (STDR) among people with age of onset of diabetes (AOD) <25 versus ≥25 years.

Methods:

A retrospective chart analysis of consecutive patients with diabetic retinopathy (DR) n = 654) treated at 14 eye care centers across India between 2018 and 2019 was performed. Patients were divided into two groups, Group 1: AOD <25 years and Group 2: AOD ≥25 years. DR and diabetic macular edema (DME) were classified using the International Clinical Classification of DR severity scale. STDR included severe nonproliferative DR (NPDR), proliferative DR (PDR), and moderate to severe DME. A multilevel mixed-effects model was used for comparison between two groups: 1) Patients with DR and AOD <25 years and 2) Patients with DR and AOD ≥25 years. Bivariate and multivariate regression analyses were used to evaluate risk factors between the two groups.

Results:

A total of 654 patients were included, 161 (307 eyes) in AOD <25 and 493 (927 eyes) in AOD >25 group. There was a higher prevalence of PDR with high-risk characteristics in AOD <25 group (24% vs. 12%) at baseline and 12-month follow-up (25% vs. 6%); P < 0.001. Systolic hypertension and poor glycemic control were risk factors in both groups, with no difference in these modifiable risk factors between groups.

Conclusion:

People with youth-onset DM are likely to present with severer form of STDR despite similar modifiable risk factors. Therefore, strict control of systolic blood pressure, glycemic status, and regular screening for DR are recommended to reduce the risk of STDR irrespective of the age of onset of diabetes.

Increased risk for microvascular complications among women with gestational diabetes in the third trimester

AIMS

The risk of microvascular disease has been thought to commence with the onset of overt diabetes. Women with gestational diabetes have only had a short-term exposure to frank hyperglycemia, but, due to underlying β-cell dysfunction, they may also have had long-term exposure to mild degrees of hyperglycemia. The aim of the study was to determine whether women with gestational diabetes are at increased risk for microalbuminuria and retinopathy compared to women with normal glucose tolerance in pregnancy.

METHODS

We recruited women aged ≥ 25 years with singleton pregnancies at 32 to 40 weeks' gestational age, with and without gestational diabetes. Women with hypertension, preeclampsia, or pre-gestational diabetes were excluded.

RESULTS

Of 372 women included in the study, 195 had gestational diabetes. The prevalence of microalbuminuria was 15% among those with gestational diabetes versus 6% in those with normal glucose tolerance (adjusted odds ratio 2.4, 95% confidence interval 1.1 to 5.2, p = 0.006). Diastolic blood pressure and HbA1c were associated with microalbuminuria. The prevalence of retinopathy did not differ between groups (10% versus 11%).

CONCLUSIONS

Women with gestational diabetes have an increased risk of microalbuminuria in the third trimester, despite having been exposed to only a brief period of overt hyperglycemia.

Glucose as a modifiable cause of atherosclerotic cardiovascular disease: Insights from type 1 diabetes and transplantation

Diabetes is a major risk factor for cardiovascular (CV) disease. In contrast to the clear benefits from treatments which reduce blood pressure and lipids, clinical trials targeting blood glucose have not shown clear CV benefits. Interventions to intensify glycemic control early in the course of diabetes may have benefits in long term observational studies (DCCT-EDIC/UKPDS), but may not be helpful if introduced late in the course of type 2 diabetes (ACCORD, ADVANCE, VA-DT). More recent CVOT in high risk subjects suggest that the benefits of SGLT2 and GLP1-RA are glucose-independent. Type 1 diabetes provides a "cleaner" model to study the links between glucose and cardiovascular disease. Abnormalities of glucose regulation in type 1 diabetes is not restricted to hyperglycemia, but includes glycemic variability and hypoglycemia. Increasingly the mechanisms linking glycemic variability and hypoglycemia as key mediators of cardiovascular complications are being understood. Furthermore, data from pancreas and islet transplantation showing reduced cardiovascular mortality and regression of intima-media thickness supports a causal role for glucose in the pathogenesis of atherosclerosis, but suggests that restoration of normal glucose regulation may be required to demonstrate substantial impact on CV risk accrued over decades of type 1 diabetes. Considering the limited organ supply and risks of immunosuppression, advances in biology (stem cell derived beta cells) or technology (automated insulin delivery systems) will be required to provide a scalable solution to deliver optimal glucose control and reduce CV risk for people with type 1 diabetes.

Definition and Classification of Diabetes and Prediabetes and Emerging Data on Phenotypes

Diabetes diagnosis has important implications for individuals. Diagnostic criteria for fasting and 2-hour plasma glucose and HbA1c are universally agreed. Intermediate hyperglycemia/prediabetes is a risk factor for diabetes and cardiovascular disease. Because risk is a continuum, determining cut-point is problematic and reflected in significant differences in recommended fasting glucose and HbA1c criteria. Many types of diabetes are recognized. Diabetes classification systems are limited by a lack of understanding of etiopathogenetic pathways leading to diminished β-cell function. The World Health Organization classification system is designed to assist clinical care decisions. Newly recognized phenotypic clusters of diabetes might inform future classification systems.

The retinopathy-derived HbA1c threshold of 6.5% for type 2 diabetes also captures the risk of diabetic nephropathy in NHANES

AIM

To determine if an HbA1c diagnostic threshold of less than 6.5% (<48 mmol/mol) could be identified based on a urinary albumin-creatinine ratio (UACR) of 30 mg/g or higher in subjects not known to have diabetes.

METHODS

A UACR was measured for 20 158 participants in the 2011-2018 nationally representative cross-sectional National Health and Nutrition Examination Surveys (NHANES; cycles 7-10 inclusive).

RESULTS

There was a significant trend for an increasing risk with a UACR of 30 mg/g or higher across increasing HbA1c categories (P < .0001). This trend was mainly attributable to the high prevalence of raised UACR in the 7.0% or higher HbA1c subgroup of subjects not previously diagnosed with diabetes. None of the odds ratios in the lower HbA1c subgroups versus the HbA1c subgroup of less than 5.0% reached significance. There were racial/ethnic differences in UACR risk (P < .0001), with White and Black subjects exhibiting little increased risk (vs. HbA1c <5.0%) until they reached an HbA1c of 7.0%, while Asian and Hispanic subjects showed some increased, but non-significant, risks at lower HbA1c levels. Maximizing the area under receiver operating characteristic curves from logistic regressions predicted an ideal HbA1c threshold of 5.8%, but there was little variation in area from 5.5% to 7.0%.

CONCLUSION

A clinically useful diagnostic threshold below 6.5% for HbA1c for elevated UACR risk was not identified, with an increased risk only obvious at an HbA1c of 7.0% or higher. Thus, the retinopathy-derived HbA1c threshold of 6.5% also captures the risk of diabetic nephropathy in NHANES.

Ethnic differences in prevalence of actionable HbA1c levels in UK Biobank: implications for screening

INTRODUCTION

Early detection and treatment of diabetes as well as its prevention help lessen longer-term complications. We determined the prevalence of pre-diabetes and undiagnosed diabetes in the UK Biobank and standardized the results to the UK general population.

RESEARCH DESIGN AND METHODS

This cross-sectional study analyzed baseline UK Biobank data on plasma glycated hemoglobin (HbA1c) to compare the prevalence of pre-diabetes and undiagnosed diabetes mellitus in white, South Asian, black, and Chinese participants. The overall and ethnic-specific results were standardized to the UK general population aged 40-70 years of age.

RESULTS

Within the UK Biobank, the overall crude prevalence was 3.6% for pre-diabetes, 0.8% for undiagnosed diabetes, and 4.4% for either. Following standardization to the UK general population, the results were similar at 3.8%, 0.8%, and 4.7%, respectively. Crude prevalence was much higher in South Asian (11.0% pre-diabetes; 3.6% undiagnosed diabetes; 14.6% either) or black (13.8% pre-diabetes; 3.0% undiagnosed diabetes; 16.8% either) participants. Only six middle-aged or old-aged South Asian individuals or seven black would need to be tested to identify an HbA1c result that merits action.

CONCLUSIONS

Single-stage population screening for pre-diabetes or undiagnosed diabetes in middle-old or old-aged South Asian and black individuals using HbA1c could be efficient and should be considered.

LDL-Cholesterol versus Glucose in Microvascular and Macrovascular Disease

BACKGROUND

The causal relationships between increased concentrations of low density lipoprotein (LDL)-cholesterol and glucose and risk of ischemic heart disease are well established. The causal contributions of LDL-cholesterol and glucose to risk of peripheral micro- and macrovascular diseases are less studied, especially in prediabetic stages and in a general population setting.

CONTENT

This review summarizes the current evidence for a causal contribution of LDL-cholesterol and glucose to risk of a spectrum of peripheral micro- and macrovascular diseases and reviews possible underlying disease mechanisms, including differences between vascular compartments, and finally discusses the clinical implications of these findings, including strategies for prevention and treatment.

SUMMARY

Combined lines of evidence suggest that LDL-cholesterol has a causal effect on risk of peripheral arterial disease and chronic kidney disease, both of which represent manifestations of macrovascular disease due to atherosclerosis and accumulation of LDL particles in the arterial wall. In contrast, there is limited evidence for a causal effect on risk of microvascular disease. Glucose has a causal effect on risk of both micro- and macrovascular disease. However, most evidence is derived from studies of individuals with diabetes. Further studies in normoglycemic and prediabetic individuals are warranted. Overall, LDL-cholesterol-lowering reduces risk of macrovascular disease, while evidence for a reduction in risk of microvascular disease is inconsistent. Glucose-lowering has a beneficial effect on risk of microvascular diseases and on risk of chronic kidney disease and estimated glomerular filtration rate (eGFR) in some studies, while results on risk of peripheral arterial disease are conflicting.

Upregulated anti-angiogenic miR-424-5p in type 1 diabetes (model of subclinical cardiovascular disease) correlates with endothelial progenitor cells, CXCR1/2 and other parameters of vascular health

Background

In spite of clinical progress, cardiovascular disease (CVD) remains the predominant cause of mortality worldwide. Overexpression studies in animals have proven miR-424-5p to have anti-angiogenic properties. As type 1 diabetes mellitus (T1DM) without CVD displays endothelial dysfunction and reduced circulating endothelial progenitor cells (cEPCs), it offers a model of subclinical CVD. Therefore, we explored miR-424-5p, cytokines and vascular health in T1DM.

Methods

Twenty-nine well-controlled T1DM patients with no CVD and 20-matched controls were studied. Cytokines IL8, TNF-α, IL7, VEGF-C, cEPCs/CD45^dimCD34⁺CD133⁺ cells and ex-vivo proangiogenic cells (PACs)/fibronectin adhesion assay (FAA) were measured. MiR-424-5p in plasma and peripheral blood mononuclear cells (PBMC) along with mRNAs in PBMC was evaluated.

Results

We found an elevation of IL7 (p = 0.008), IL8 (p = 0.003), TNF-α (p = 0.041), VEGF-C (p = 0.013), upregulation of mRNA CXCR1 (p = 0.009), CXCR2 (p < 0.001) and reduction of cEPCs (p < 0.001), PACs (p < 0.001) and FAA (p = 0.017) in T1DM. MiR-424-5p was upregulated in T1DM in PBMC (p < 0.001). MiR-424-5p was negatively correlated with cEPCs (p = 0.006), PACs (p = 0.005) and FAA (p < 0.001) and positively with HbA_1c (p < 0.001), IL7 (p = 0.008), IL8 (p = 0.017), VEGF-C (p = 0.007), CXCR1 (p = 0.02) and CXCR2 (p = 0.001). ROC curve analyses showed (1) miR-424-5p to be a biomarker for T1DM (p < 0.001) and (2) significant upregulation of miR-424-5p, defining subclinical CVD, occurred at HbA_1c of 46.5 mmol/mol (p = 0.002).

Conclusion

We validated animal research on anti-angiogenic properties of miR-424-5p in T1DM. MiR-424-5p may be a biomarker for onset of subclinical CVD at HbA_1c of 46.5 mmol/mol (pre-diabetes). Thus, miR-424-5p has potential use for CVD monitoring whilst anti-miR-424-5p-based therapies may be used to reduce CVD morbidity/mortality in T1DM.

Association between insulin resistance and post-ischaemic stroke outcome in patients without diabetes: protocol for a systematic review and meta-analysis

INTRODUCTION

Insulin resistance is an independent risk factor for atherosclerosis, coronary artery disease and ischaemic stroke. Currently, insulin resistance is not usually included in post-stroke risk stratification. This systematic review and meta-analysis intends to determine if available scientific knowledge supports an association between insulin resistance and post-stroke outcomes in patients without diabetes.

METHODS AND ANALYSIS

The authors will conduct a literature search in Medline, Embase, Web of Science and Cochrane Central. The review will include studies that assess the association between elevated insulin homeostasis model of insulin resistance (HOMA-IR) and post-stroke outcome (functional outcome and recurrent stroke). The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will be used. The primary outcome will be post-stroke functional outcome (Modified Rankin Scale), and the secondary outcome will be recurrent ischaemic stroke. Comparison of outcome will be made between highest and lowest HOMA-IR range (as defined in each article included in this systematic review). Risk of bias will be assessed qualitatively. Meta-analysis will be performed if sufficient homogeneity exists between studies. Heterogeneity of outcomes will be assessed by I².

ETHICS AND DISSEMINATION

No human or animal subjects or samples were/will be used. The results will be published in a peer-reviewed journal, and will be disseminated at local and international neurology conferences.

PROSPERO REGISTRATION NUMBER

CRD42020173608.

Independent effects of 2hPG, FPG and HbA1c on cardiovascular risk: Analysis of a nationally representative sample from China

AIMS

To evaluate the independence of the effect of 2-hour post-load plasma glucose (2hPG), fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) on cardiovascular disease (CVD) after adjusting for each other and non-glycemic factors.

METHODS

We analyzed data from a nationally representative sample of 174,329 Chinese adults from a survey conducted in 2013-2014. The associations of glycemic measures with the risk of CVD were examined and compared by using logistic regression analyses.

RESULTS

After adjusting for non-glycemic factors, the odds ratio for one standard-deviation increase of 2hPG, FPG and HbA1c was 1.08 (95% confidence interval [CI]: 1.05-1.11), 1.02 (95% CI: 0.99-1.06) and 1.05 (95% CI: 1.02-1.07), respectively. The odds ratio for 2hPG (1.10, 95% CI: 1.05-1.16) remained statistically significant after FPG and HbA1c were added to the models, whereas the odds ratios for FPG and HbA1c became statistically insignificant after 2hPG was adjusted for. The results remained consistent across various scenarios.

CONCLUSIONS

2hPG showed an effect on cardiovascular risk which was independent from FPG and HbA1c, whereas whether the effects of FPG and HbA1c were independent from 2hPG was open to question. This finding calls for more research on how to better use FPG and HbA1c in diagnosing diabetes.

What factors explain the much higher diabetes prevalence in Russia compared with Norway? Major sex differences in the contribution of adiposity

INTRODUCTION

Compared with many other countries Russia has a high prevalence of diabetes in men and women. However, contrary to what is found in most other populations, the risk is greater among women than men. The reasons for this are unclear.

RESEARCH DESIGN AND METHODS

Prevalence and risk factors for diabetes at ages 40-69 years were compared in two population-based studies: Know Your Heart (KYH) (Russia, 2015-2018, n=4121) and the seventh wave of the Tromsø Study (Tromsø 7) (Norway, 2015-2016, n=17 649). Diabetes was defined by the level of glycated hemoglobin and/or self-reported diabetes and/or diabetes medication use. Marginal structural models were used to estimate the role of key risk factors for diabetes in differences between the studies.

RESULTS

Age-standardized prevalence of diabetes was higher in KYH compared with Tromsø 7 in men (11.6% vs 6.2%) and in women (13.2% vs 4.3%). Age-adjusted ORs for diabetes in KYH compared with Tromsø 7 were 2.01 (95% CI 1.68 to 2.40) for men and 3.66 (95% CI 3.13 to 4.26) for women. Adiposity (body mass index and waist circumference) explained none of this effect for men but explained 46.0% (39.6, 53.8) for women. Addition of smoking and C reactive protein, as further mediators, slightly increased the percentage explained of the difference between studies to 55.5% (46.5, 66.0) for women but only to 9.9% (-0.6, 20.8) for men.

CONCLUSIONS

Adiposity is a key modifiable risk factor that appears to explain half of the almost threefold higher female prevalence of diabetes in Russia compared with Norway, but none of the twofold male difference.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Sex Differences in the Risk of Coronary Heart Disease Associated With Type 2 Diabetes: A Mendelian Randomization Analysis

OBJECTIVE

Observational studies have demonstrated that type 2 diabetes is a stronger risk factor for coronary heart disease (CHD) in women compared with men. However, it is not clear whether this reflects a sex differential in the causal effect of diabetes on CHD risk or results from sex-specific residual confounding.

RESEARCH DESIGN AND METHODS

Using 270 single nucleotide polymorphisms (SNPs) for type 2 diabetes identified in a type 2 diabetes genome-wide association study, we performed a sex-stratified Mendelian randomization (MR) study of type 2 diabetes and CHD using individual participant data in UK Biobank (251,420 women and 212,049 men). Weighted median, MR-Egger, MR-pleiotropy residual sum and outlier, and radial MR from summary-level analyses were used for pleiotropy assessment.

RESULTS

MR analyses showed that genetic risk of type 2 diabetes increased the odds of CHD for women (odds ratio 1.13 [95% CI 1.08-1.18] per 1-log unit increase in odds of type 2 diabetes) and men (1.21 [1.17-1.26] per 1-log unit increase in odds of type 2 diabetes). Sensitivity analyses showed some evidence of directional pleiotropy; however, results were similar after correction for outlier SNPs.

CONCLUSIONS

This MR analysis supports a causal effect of genetic liability to type 2 diabetes on risk of CHD that is not stronger for women than men. Assuming a lack of bias, these findings suggest that the prevention and management of type 2 diabetes for CHD risk reduction is of equal priority in both sexes.

Diabetes, Brain Infarcts, Cognition, and Small Vessels in the Canadian Alliance for Healthy Hearts and Minds Study

BACKGROUND

Diabetes is a risk factor for cerebrovascular disease and cognitive impairment. The anatomical basis for this is uncertain.

METHODS

The Canadian Alliance for Healthy Hearts and Minds collected brain and carotid magnetic resonance imaging (MRI) and 2 cognitive tests (the Digit Symbol Substitution Test and the Montreal Cognitive Assessment test) in a cross-sectional sample of men and women. Brain MRIs identified brain infarcts (BI), lacunar BI, high white matter hyperintensity (WMH), vascular brain injury (VBI; BI or high WMH), and small vessel VBI (lacunar BI or high WMH). Carotid MRIs estimated carotid wall volume, a measure of subclinical atherosclerosis. Cognitive scores were standardized to each site's mean score, and cognitive impairment was identified by 1 or both test scores ≤1 standard deviation below the site's mean score on that test.

RESULTS

The 7733 participants included 495 participants (6.4%) with diabetes, of whom 388 were taking diabetes drugs. After age and sex adjustment, diabetes was independently associated with BI (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.05, 2.24), VBI (OR 1.64, 95% CI 1.26, 2.13), small vessel VBI (OR 1.67, 95% CI 1.28, 2.19), and cognitive impairment (OR 1.47, 95% CI 1.20, 1.80). The association between diabetes and small vessel VBI persisted after adjustment for cerebrovascular disease risk factors and nonlacunar infarcts (OR 1.52, 95% CI 1.15, 2.01), and the association with cognitive impairment persisted after adjustment for small vessel VBI (OR 1.27, 95% CI 1.03, 1.56).

CONCLUSION

Small vessel disease characterizes much of the relationship between diabetes and VBI. However, additional factors are required to disentangle the relationship between diabetes and cognitive impairment.

The Association between Social Determinants of Health and Self-Reported Diabetic Retinopathy: An Exploratory Analysis

One-third of Americans with diabetes will develop diabetic retinopathy (DR), the leading cause of blindness in working-age Americans. Social determinants of health (SDOHs) are conditions in a person’s environment that may impact health. The objective of this study was to determine whether there is an association between SDOHs and DR in patients with type II diabetes. This cross-section study used data from the 2018 Behavioral Risk Factor Surveillance System (BRFSS). This study included people with self-reported diabetes in the US in 2018 (n = 60,703). Exposure variables included homeownership, marital status, income, health care coverage, completed level of education, and urban vs. rural environment. The outcome variable was DR. Logistic regression analysis were applied to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Alaskan Native/Native American (OR 2.11; 95% CI: 1.14–3.90), out of work (OR 2.82; 95% CI: 1.62–4.92), unable to work (OR 2.14; 95% CI: 1.57–2.91), did not graduate high school (OR 1.91; 95% CI: 1.30–2.79), only graduated high school (OR 1.43; 95% CI 1.08–1.97), or only attended college or technical school without graduating (OR 1.42; 95% CI: 1.09–1.86) were SDOHs associated with DR in patients with diabetes. Health care providers should identify these possible SDOHs affecting their diabetic patients.

Prevalence of Prediabetes and Undiagnosed Diabetes Among Kuwaiti Adults: A Cross-Sectional Study

PURPOSE

This study aimed to estimate the prevalence of prediabetes and undiagnosed type 2 diabetes mellitus (T2DM) according to fasting plasma glucose (FPG), 2-h plasma glucose (PG) during oral glucose tolerance test (OGTT), and glycated hemoglobin (HbA1c) among a sample of Kuwaiti adults. In addition, associations of prediabetes and undiagnosed T2DM with sex, age, and body mass index (BMI) were assessed.

METHODS

A cross-sectional study enrolled 1238 subjects aged 18-65 years who reported no prior history of DM. After overnight fasting, FPG and HbA1c were measured in the total study sample, and 2-h PG during a 75-g OGTT was measured in a subsample of 155 subjects. Prediabetes and undiagnosed T2DM were defined according to the American Diabetes Association criteria. Associations were assessed using Poisson regression with robust variance estimation, and adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

We enrolled a total of 618 males and 620 females, with an average age of 43.0 years. The prevalence of prediabetes was estimated to be 47.9% (588/1228) by FPG, 36.8% (57/155) by 2-h PG OGTT, and 31.0% (355/1144) by HbA1c. The prevalence of undiagnosed T2DM was 6.9% (85/1228) by FPG, 11.0% (17/155) by 2-h PG OGTT, and 4.9% (56/1144) by HbA1c. Sex-related differences in the prevalence of prediabetes and undiagnosed T2DM were observed. Prediabetes and undiagnosed T2DM prevalence estimates showed increasing trends as age and BMI increased. For instance, obese subjects compared to under/normal weight subjects had an increased HbA1c-defined prediabetes prevalence (aPR = 1.62, 95% CI: 1.21-2.16).

CONCLUSION

Prediabetes and undiagnosed T2DM affect a considerable proportion of Kuwaiti adults, and variations across sex, age, and BMI exist. Hence, early identification and management of affected individuals may help reduce the public health burden.