Critical Role of CD55 in Controlling Wound Healing.

How reparative processes are coordinated following injury is incompletely understood. In recent studies, we showed that autocrine C3a and C5a receptor (C3ar1 and C5ar1) G protein-coupled receptor signaling plays an obligate role in vascular endothelial growth factor receptor 2 growth signaling in vascular endothelial cells. We documented the same interconnection for platelet-derived growth factor receptor growth signaling in smooth muscle cells, epidermal growth factor receptor growth signaling in epidermal cells, and fibroblast growth factor receptor signaling in fibroblasts, indicative of a generalized cell growth regulatory mechanism. In this study, we examined one physiological consequence of this signaling circuit. We found that disabling CD55 (also known as decay accelerating factor), which lifts restraint on autocrine C3ar1/C5ar1 signaling, concomitantly augments the growth of each cell type. The mechanism is heightened C3ar1/C5ar1 signaling resulting from the loss of CD55's restraint jointly potentiating growth factor production by each cell type. Examination of the effect of lifted CD55 restraint in four types of injury (burn, corneal denudation, ear lobe puncture, and reengraftment of autologous skin) showed that disabled CD55 function robustly accelerated healing in all cases, whereas disabled C3ar1/C5ar1 signaling universally retarded it. In wild-type mice with burns or injured corneas, applying a mouse anti-mouse CD55 blocking Ab (against CD55's active site) to wounds accelerated the healing rate by 40-70%. To our knowledge, these results provide new insights into mechanisms that underlie wound repair and open up a new tool for accelerating healing.

Long-Term Complications in Youth-Onset Type 2 Diabetes.

BACKGROUND: The prevalence of type 2 diabetes in youth is increasing, but little is known regarding the occurrence of related complications as these youths transition to adulthood. METHODS: We previously conducted a multicenter clinical trial (from 2004 to 2011) to evaluate the effects of one of three treatments (metformin, metformin plus rosiglitazone, or metformin plus an intensive lifestyle intervention) on the time to loss of glycemic control in participants who had onset of type 2 diabetes in youth. After completion of the trial, participants were transitioned to metformin with or without insulin and were enrolled in an observational follow-up study (performed from 2011 to 2020), which was conducted in two phases; the results of this follow-up study are reported here. Assessments for diabetic kidney disease, hypertension, dyslipidemia, and nerve disease were performed annually, and assessments for retinal disease were performed twice. Complications related to diabetes identified outside the study were confirmed and adjudicated. RESULTS: At the end of the second phase of the follow-up study (January 2020), the mean (±SD) age of the 500 participants who were included in the analyses was 26.4±2.8 years, and the mean time since the diagnosis of diabetes was 13.3±1.8 years. The cumulative incidence of hypertension was 67.5%, the incidence of dyslipidemia was 51.6%, the incidence of diabetic kidney disease was 54.8%, and the incidence of nerve disease was 32.4%. The prevalence of retinal disease, including more advanced stages, was 13.7% in the period from 2010 to 2011 and 51.0% in the period from 2017 to 2018. At least one complication occurred in 60.1% of the participants, and at least two complications occurred in 28.4%. Risk factors for the development of complications included minority race or ethnic group, hyperglycemia, hypertension, and dyslipidemia. No adverse events were recorded during follow-up. CONCLUSIONS: Among participants who had onset of type 2 diabetes in youth, the risk of complications, including microvascular complications, increased steadily over time and affected most participants by the time of young adulthood. Complications were more common among participants of minority race and ethnic group and among those with hyperglycemia, hypertension, and dyslipidemia. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov numbers, NCT01364350 and NCT02310724.).

Re-analysis and meta-analysis of summary statistics from gene-environment interaction studies.

MOTIVATION: statistics from genome-wide association studies enable many valuable downstream analyses that are more efficient than individual-level data analysis while also reducing privacy concerns. As growing sample sizes enable better-powered analysis of gene-environment interactions, there is a need for gene-environment interaction-specific methods that manipulate and use summary statistics. RESULTS: We introduce two tools to facilitate such analysis, with a focus on statistical models containing multiple gene-exposure and/or gene-covariate interaction terms. REGEM (RE-analysis of GEM summary statistics) uses summary statistics from a single, multi-exposure genome-wide interaction study to derive analogous sets of summary statistics with arbitrary sets of exposures and interaction covariate adjustments. METAGEM (META-analysis of GEM summary statistics) extends current fixed-effects meta-analysis models to incorporate multiple exposures from multiple studies. We demonstrate the value and efficiency of these tools by exploring alternative methods of accounting for ancestry-related population stratification in genome-wide interaction study in the UK Biobank as well as by conducting a multi-exposure genome-wide interaction study meta-analysis in cohorts from the diabetes-focused ProDiGY consortium. These programs help to maximize the value of summary statistics from diverse and complex gene-environment interaction studies. AVAILABILITY AND IMPLEMENTATION: REGEM and METAGEM are open-source projects freely available at https://github.com/large-scale-gxe-methods/REGEM and https://github.com/large-scale-gxe-methods/METAGEM.

The power of TOPMed imputation for the discovery of Latino-enriched rare variants associated with type 2 diabetes.

AIMS/HYPOTHESIS: The Latino population has been systematically underrepresented in large-scale genetic analyses, and previous studies have relied on the imputation of ungenotyped variants based on the 1000 Genomes (1000G) imputation panel, which results in suboptimal capture of low-frequency or Latino-enriched variants. The National Heart, Lung, and Blood Institute (NHLBI) Trans-Omics for Precision Medicine (TOPMed) released the largest multi-ancestry genotype reference panel representing a unique opportunity to analyse rare genetic variations in the Latino population. We hypothesise that a more comprehensive analysis of low/rare variation using the TOPMed panel would improve our knowledge of the genetics of type 2 diabetes in the Latino population. METHODS: We evaluated the TOPMed imputation performance using genotyping array and whole-exome sequence data in six Latino cohorts. To evaluate the ability of TOPMed imputation to increase the number of identified loci, we performed a Latino type 2 diabetes genome-wide association study (GWAS) meta-analysis in 8150 individuals with type 2 diabetes and 10,735 control individuals and replicated the results in six additional cohorts including whole-genome sequence data from the All of Us cohort. RESULTS: Compared with imputation with 1000G, the TOPMed panel improved the identification of rare and low-frequency variants. We identified 26 genome-wide significant signals including a novel variant (minor allele frequency 1.7%; OR 1.37, p=3.4 × 10-9). A Latino-tailored polygenic score constructed from our data and GWAS data from East Asian and European populations improved the prediction accuracy in a Latino target dataset, explaining up to 7.6% of the type 2 diabetes risk variance. CONCLUSIONS/INTERPRETATION: Our results demonstrate the utility of TOPMed imputation for identifying low-frequency variants in understudied populations, leading to the discovery of novel disease associations and the improvement of polygenic scores. DATA AVAILABILITY: Full summary statistics are available through the Common Metabolic Diseases Knowledge Portal ( https://t2d.hugeamp.org/downloads.html ) and through the GWAS catalog ( https://www.ebi.ac.uk/gwas/ , accession ID: GCST90255648). Polygenic score (PS) weights for each ancestry are available via the PGS catalog ( https://www.pgscatalog.org , publication ID: PGP000445, scores IDs: PGS003443, PGS003444 and PGS003445).

Initial Insights into the Genetic Variation Associated with Metformin Treatment Failure in Youth with Type 2 Diabetes.

Metformin is the first-line treatment for type 2 diabetes (T2D) in youth but with limited sustained glycemic response. To identify common variants associated with metformin response, we used a genome-wide approach in 506 youth from the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study and examined the relationship between T2D partitioned polygenic scores (pPS), glycemic traits, and metformin response in these youth. Several variants met a suggestive threshold (P < 1 × 10-6), though none including published adult variants reached genome-wide significance. We pursued replication of top nine variants in three cohorts, and rs76195229 in ATRNL1 was associated with worse metformin response in the Metformin Genetics Consortium (n = 7,812), though statistically not being significant after Bonferroni correction (P = 0.06). A higher ß-cell pPS was associated with a lower insulinogenic index (P = 0.02) and C-peptide (P = 0.047) at baseline and higher pPS related to two insulin resistance processes were associated with increased C-peptide at baseline (P = 0.04,0.02). Although pPS were not associated with changes in glycemic traits or metformin response, our results indicate a trend in the association of the ß-cell pPS with reduced ß-cell function over time. Our data show initial evidence for genetic variation associated with metformin response in youth with T2D.

Pediatric Diabetic Retinopathy: Updates in Prevalence, Risk Factors, Screening, and Management.

PURPOSE OF REVIEW: Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus and a major cause of vision loss worldwide. The purpose of this review is to provide an update on the prevalence of diabetic retinopathy in youth, discuss risk factors, and review recent advances in diabetic retinopathy screening. RECENT FINDINGS: While DR has long been considered a microvascular complication, recent data suggests that retinal neurodegeneration may precede the vascular changes associated with DR. The prevalence of DR has decreased in type 1 diabetes (T1D) patients following the results of the Diabetes Control and Complications Trial and implementation of intensive insulin therapy, with prevalence ranging from 14-20% before the year 2000 to 3.7-6% after 2000. In contrast, the prevalence of diabetic retinopathy in pediatric type 2 diabetes (T2D) is higher, ranging from 9.1-50%. Risk factors for diabetic retinopathy are well established and include glycemic control, diabetes duration, hypertension, and hyperlipidemia, whereas diabetes technology use including insulin pumps and continuous glucose monitors has been shown to have protective effects. Screening for DR is recommended for youth with T1D once they are aged ≥ 11 years or puberty has started and diabetes duration of 3-5 years. Pediatric T2D patients are advised to undergo screening at or soon after diagnosis, and annually thereafter, due to the insidious nature of T2D. Recent advances in DR screening methods including point of care and artificial intelligence technology have increased access to DR screening, while being cost-saving to patients and cost-effective to healthcare systems. While the prevalence of diabetic retinopathy in youth with T1D has been declining over the last few decades, there has been a significant increase in the prevalence of DR in youth with T2D. Improving access to diabetic retinopathy screening using novel screening methods may help improve detection and early treatment of diabetic retinopathy.

Frequency of Evidence-Based Screening for Retinopathy in Type 1 Diabetes.

BACKGROUND: In patients who have had type 1 diabetes for 5 years, current recommendations regarding screening for diabetic retinopathy include annual dilated retinal examinations to detect proliferative retinopathy or clinically significant macular edema, both of which require timely intervention to preserve vision. During 30 years of the Diabetes Control and Complications Trial (DCCT) and its longitudinal follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, retinal photography was performed at intervals of 6 months to 4 years. METHODS: We used retinal photographs from the DCCT/EDIC study to develop a rational screening frequency for retinopathy. Markov modeling was used to determine the likelihood of progression to proliferative diabetic retinopathy or clinically significant macular edema in patients with various initial retinopathy levels (no retinopathy or mild, moderate, or severe nonproliferative diabetic retinopathy). The models included recognized risk factors for progression of retinopathy. RESULTS: Overall, the probability of progression to proliferative diabetic retinopathy or clinically significant macular edema was limited to approximately 5% between retinal screening examinations at 4 years among patients who had no retinopathy, 3 years among those with mild retinopathy, 6 months among those with moderate retinopathy, and 3 months among those with severe nonproliferative diabetic retinopathy. The risk of progression was also closely related to mean glycated hemoglobin levels. The risk of progression from no retinopathy to proliferative diabetic retinopathy or clinically significant macular edema was 1.0% over 5 years among patients with a glycated hemoglobin level of 6%, as compared with 4.3% over 3 years among patients with a glycated hemoglobin level of 10%. Over a 20-year period, the frequency of eye examinations was 58% lower with our practical, evidence-based schedule than with routine annual examinations, which resulted in substantial cost savings. CONCLUSIONS: Our model for establishing an individualized schedule for retinopathy screening on the basis of the patient's current state of retinopathy and glycated hemoglobin level reduced the frequency of eye examinations without delaying the diagnosis of clinically significant disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; DCCT/EDIC ClinicalTrials.gov numbers, NCT00360893 and NCT00360815 .).

Circulating adhesion molecules and associations with HbA1c, hypertension, nephropathy, and retinopathy in the Treatment Options for type 2 Diabetes in Adolescent and Youth study.

BACKGROUND: The Treatment Options for type 2 Diabetes in Adolescent and Youth study, a randomized clinical trial of three treatments for type 2 diabetes (T2DM) in youth, demonstrated treatment failure (defined as sustained HbA1c ≥8%, or inability to wean insulin after 3 months after acute metabolic decomposition) in over half of the participants. Given that binding of mononuclear cells to vascular endothelium, initiated by cellular adhesion molecules and chemokines, is an early step in vascular injury, we sought to evaluate (a) changes in cellular adhesion molecule levels during the trial; (b) effect of diabetes treatment; and (c) association of markers with HbA1c, hypertension, hypercholesterolemia, nephropathy, and retinopathy. METHODS: Participants (n = 515 of 699) that had baseline assessment of adhesion molecules (monocyte chemoattractant protein-1 [MCP-1], vascular cell adhesion marker [VCAM], intercellular adhesion marker [ICAM], and E-Selectin) and at least one other assessment, measured at month 12, 24, or 36, were included. RESULTS: Over 1 to 3 years, significant increases in MCP-1 and decreases in VCAM (both P < .0001) concentrations were found; however, no significant interactions were identified with treatment group for any molecule. For every 1% increase in HbA1c, ICAM increased by 1.8%, VCAM by 1.5%, and E-selectin by 6.8% (all P < .0001). E-selectin increased by 3.7% and 4.2% for every 10 mm Hg increase in systolic and diastolic blood pressure, respectively (both P < .0001). ICAM was 10.2% higher and E-selectin was 15.5% higher in participants with microalbuminuria (both P < .01). There was no significant association of adhesion molecule levels with retinopathy. CONCLUSION: Concentrations of cellular adhesion molecules rise with increasing HbA1c in youth with T2DM, and are associated with blood pressure and microalbuminuria, markers of vascular injury.

Beta cell function and insulin sensitivity in obese youth with maturity onset diabetes of youth mutations vs type 2 diabetes in TODAY: Longitudinal observations and glycemic failure.

OBJECTIVE: In treatment options for type 2 diabetes in adolescents and youth (TODAY), 4.5% of obese youth clinically diagnosed with type 2 diabetes (T2D) had genetic variants consistent with maturity onset diabetes of youth (MODY) diagnosis. The course of IS and ß-cell function in obese youth with MODY remains unknown. In this secondary analysis, we examined IS and ß-cell function in MODY vs. non-MODY obese youth at randomization and over time. METHODS: Genetic data in TODAY included 426 non-MODY (T2D) and 22 MODY youth (7 glucokinase MODY mutation positive [GCK-MODY], 12 hepatocyte nuclear factor MODY mutation positive [HNF-MODY], 2 Insulin gene mutation [insulin (INS)-MODY], and 1 Kruppel-like factor 11 [KLF11-MODY]). Oral glucose tolerance test (OGTT)-derived IS, C-peptide index, and ß-cell function relative to IS oral disposition index (oDI) was measured at randomization, and over 24 months in addition to total and high-molecular-weight adiponectin (HMWA). RESULTS: At randomization, IS, total adiponectin, and HMWA were significantly higher in the two MODY groups than in non-MODY. ß-cell function measured by C-peptide oDI was 3-fold higher in GCK-MODY than in HNF-MODY and 1.5-fold higher than non-MODY (P for both <.05). Glycemic failure rate was 75.0% in HNF-MODY, 46.9% in non-MODY, and zero in GCK-MODY youth. While the changes in IS and oDI were not different among the three groups in the first 6 months, IS improved from 6 to 24 months in HNF-MODY vs GCK-MODY youth. CONCLUSIONS: In TODAY, ß-cell function at randomization was worse in obese HNF-MODY youth compared with GCK-MODY youth, while insulin sensitivity was worse in non-MODY compared with the other two MODY groups. Over time, IS showed the greatest improvement in HNF-MODY youth. This raises the possibility that TODAY therapeutic modalities of insulin sensitization in these obese HNF-MODY youth may have played a beneficial role.

Screening eye exams in youth with type 1 diabetes under 18 years of age: Once may be enough?

Case series and registry data suggest that diabetic retinopathy requiring treatment is rare in youth with type 1 diabetes (T1D) prior to 18 years of age. We evaluated this question in the standardized clinical trial setting by retrospectively reviewing diabetic retinopathy examinations from participants in the Diabetes Control and Complications Trial (DCCT) who were 13 to <18 years of age at randomization. Standardized stereoscopic 7-field fundus photographs were obtained every 6 months during DCCT (1983-1993). Photographs were graded centrally using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Transitions in diabetic retinopathy status over time were described. A total of 195 participants with median baseline glycated hemoglobin (HbA1c) of 9.3% (103 in the conventional and 92 in the intensive treatment groups) had an average of 5.3 diabetic retinopathy assessments during 2.3 years of follow-up (range 1-11) while under 18 years of age during the DCCT. No participant developed severe non-proliferative diabetic retinopathy or proliferative diabetic retinopathy and only one participant (in the intensive group) reached clinically significant macular edema (CSME) while less than 18 years of age. In this incident case, baseline characteristics included diabetes duration 9.3 years, HbA1c 10.3%, LDL 131 mg/dL, and mild non-proliferative diabetic retinopathy (35/35 ETDRS scale); CSME resolved without treatment. Similar analyses using age cut-offs of <19, 20, or 21 years showed a slight rise in diabetic retinopathy requiring treatment over late adolescence. Clinical trial evidence suggests that frequent eye exams may not be universally necessary in youth <18 years of age with T1D.

RISK FACTORS FOR HEARING IMPAIRMENT IN TYPE 1 DIABETES.

Objective: Studies have demonstrated that glycated hemoglobin (HbA1c) is a significant predictor of hearing impairment in type 1 diabetes. We identified additional factors associated with hearing impairment in participants with type 1 diabetes from the Diabetes Control and Complications Trial and its observational follow-up, the Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. Methods: A total of 1,150 DCCT/EDIC participants were recruited for the Hearing Study. A medical history, physical measurements, and a self-administered hearing questionnaire were obtained. Audiometry was performed by study-certified personnel and assessed centrally. Logistic regression models assessed the association of risk factors and comorbidities with speech- and high-frequency hearing impairment. Results: Mean age was 55 ± 7 years, duration of diabetes 34 ± 5 years, and DCCT/EDIC HbA1c 7.9 ± 0.9% (63 mmol/mol). In multivariable models, higher odds of speech-frequency impairment were significantly associated with older age, higher HbA1c, history of noise exposure, male sex, and higher triglycerides. Higher odds of high-frequency impairment were associated with older age, male sex, history of noise exposure, higher skin intrinsic florescence (SIF) as a marker of tissue glycation, higher HbA1c, nonprofessional/nontechnical occupations, sedentary activity, and lower low-density-lipoprotein cholesterol. Among participants who previously completed computed tomography and carotid ultrasonography, coronary artery calcification (CAC) >0 and carotid intima-medial thickness were significantly associated with high-but not speech-frequency impairment. Conclusion: Consistent with previous reports, male sex, age, several metabolic factors, and noise exposure are independently associated with hearing impairment. The association with SIF further emphasizes the importance of glycemia-as a modifiable risk factor-over time. In addition, the macrovascular contribution of CAC is novel and important. Abbreviations: AER = albumin excretion rate; CAC = coronary artery calcification; CVD = cardiovascular disease; DCCT/EDIC = Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications; eGFR = estimated glomerular filtration rate; ETDRS = Early Treatment Diabetic Retinopathy Study; HbA1c = glycated hemoglobin; HDL = high-density lipoprotein; IMT = intima-media thickness; LDL = low-density lipoprotein; NHANES = National Health and Nutrition Examination Survey; OR = odds ratio; SIF = skin intrinsic fluorescence; T1D = type 1 diabetes.

Meta-genome-wide association studies identify a locus on chromosome 1 and multiple variants in the MHC region for serum C-peptide in type 1 diabetes.

AIMS/HYPOTHESIS: The aim of this study was to identify genetic variants associated with beta cell function in type 1 diabetes, as measured by serum C-peptide levels, through meta-genome-wide association studies (meta-GWAS). METHODS: We performed a meta-GWAS to combine the results from five studies in type 1 diabetes with cross-sectionally measured stimulated, fasting or random C-peptide levels, including 3479 European participants. The p values across studies were combined, taking into account sample size and direction of effect. We also performed separate meta-GWAS for stimulated (n = 1303), fasting (n = 2019) and random (n = 1497) C-peptide levels. RESULTS: In the meta-GWAS for stimulated/fasting/random C-peptide levels, a SNP on chromosome 1, rs559047 (Chr1:238753916, T>A, minor allele frequency [MAF] 0.24-0.26), was associated with C-peptide (p = 4.13 × 10-8), meeting the genome-wide significance threshold (p < 5 × 10-8). In the same meta-GWAS, a locus in the MHC region (rs9260151) was close to the genome-wide significance threshold (Chr6:29911030, C>T, MAF 0.07-0.10, p = 8.43 × 10-8). In the stimulated C-peptide meta-GWAS, rs61211515 (Chr6:30100975, T/-, MAF 0.17-0.19) in the MHC region was associated with stimulated C-peptide (ß [SE] = - 0.39 [0.07], p = 9.72 × 10-8). rs61211515 was also associated with the rate of stimulated C-peptide decline over time in a subset of individuals (n = 258) with annual repeated measures for up to 6 years (p = 0.02). In the meta-GWAS of random C-peptide, another MHC region, SNP rs3135002 (Chr6:32668439, C>A, MAF 0.02-0.06), was associated with C-peptide (p = 3.49 × 10-8). Conditional analyses suggested that the three identified variants in the MHC region were independent of each other. rs9260151 and rs3135002 have been associated with type 1 diabetes, whereas rs559047 and rs61211515 have not been associated with a risk of developing type 1 diabetes. CONCLUSIONS/INTERPRETATION: We identified a locus on chromosome 1 and multiple variants in the MHC region, at least some of which were distinct from type 1 diabetes risk loci, that were associated with C-peptide, suggesting partly non-overlapping mechanisms for the development and progression of type 1 diabetes. These associations need to be validated in independent populations. Further investigations could provide insights into mechanisms of beta cell loss and opportunities to preserve beta cell function.

Racial Differences in the Relationship of Glucose Concentrations and Hemoglobin A1c Levels.

Background: Debate exists as to whether the higher hemoglobin A1c (HbA1c) levels observed in black persons than in white persons are due to worse glycemic control or racial differences in the glycation of hemoglobin. Objective: To determine whether a racial difference exists in the relationship of mean glucose and HbA1c. Design: Prospective, 12-week observational study. Setting: 10 diabetes centers in the United States. Participants: 104 black persons and 104 white persons aged 8 years or older who had had type 1 diabetes for at least 2 years and had an HbA1c level of 6.0% to 12.0%. Measurements: Mean glucose concentration, measured by using continuous glucose monitoring and compared by race with HbA1c, glycated albumin, and fructosamine values. Results: The mean HbA1c level was 9.1% in black persons and 8.3% in white persons. For a given HbA1c level, the mean glucose concentration was significantly lower in black persons than in white persons (P = 0.013), which was reflected in mean HbA1c values in black persons being 0.4 percentage points (95% CI, 0.2 to 0.6 percentage points) higher than those in white persons for a given mean glucose concentration. In contrast, no significant racial differences were found in the relationship of glycated albumin and fructosamine levels with the mean glucose concentration (P > 0.20 for both comparisons). Limitation: There were too few participants with HbA1c levels less than 6.5% to generalize the results to such individuals. Conclusion: On average, HbA1c levels overestimate the mean glucose concentration in black persons compared with white persons, possibly owing to racial differences in the glycation of hemoglobin. However, because race only partially explains the observed HbA1c differences between black persons and white persons, future research should focus on identifying and modifying barriers impeding improved glycemic control in black persons with diabetes. Primary Funding Source: Helmsley Charitable Trust.

Barriers to participation in industry-sponsored clinical trials in pediatric type 2 diabetes.

BACKGROUND: The rapid emergence of type 2 diabetes (T2D) in the pediatric population has left pediatric endocrinologists with limited artillery in terms of management. While multiple medications are available for adults, Food and Drug Administration (FDA)-approved medications in children are limited to only metformin and insulin. Additional treatment options require randomized controlled trials, yet heretofore several barriers at the participant and institutional level have impeded these studies from proceeding in children and adolescents. Identification of the most challenging obstacles that pediatric endocrinologists experience in participating in industry-sponsored T2D trials may facilitate development of feasible platforms for future studies. MATERIALS AND METHODS: We conducted an anonymous online survey consisting of 31 questions that assessed potential barriers to industry-sponsored clinical trials in pediatric patients with T2D. The survey was sent to members of the Pediatric Endocrine Society (PES), and members conducted the survey between October and November of 2014. As part of the survey, respondents rated the significance of several possible barriers to participation in industry-sponsored T2D studies. RESULTS: We received a total of 207 responses from members of PES. Baseline demographics showed that 50% of represented institutions care for 50 or fewer T2D patients age 18 years and younger; 70% of institutions diagnose 20 or fewer new T2D cases per year; and 3 racial groups predominated: African American, Hispanic, and Caucasian. A total of 70% of responders have a research infrastructure to participate in clinical trials, but only half have dedicated research nurses. Protocol restrictions on participant recruitment due to current glycemic control or medication use as well as frequent visit schedules were reported to be major obstacles. In addition, the financial support provided to centers to carry out the studies is insufficient. CONCLUSIONS: Efforts must be made to ease the burden of research participation on both pediatric T2D patients as well as pediatric endocrinologists.

Assessing Priorities in a Statewide Cardiovascular and Diabetes Health Collaborative Based on the Results of a Needs Assessment: Cross-Sectional Survey Study.

BACKGROUND: The Ohio Cardiovascular and Diabetes Health Collaborative (Cardi-OH) unites general and subspecialty medical staff at the 7 medical schools in Ohio with community and public health partnerships to improve cardiovascular and diabetes health outcomes and eliminate disparities in Ohio's Medicaid population. Although statewide collaboratives exist to address health improvements, few deploy needs assessments to inform their work. OBJECTIVE: Cardi-OH conducts an annual needs assessment to identify high-priority clinical topics, screening practices, policy changes for home monitoring devices and referrals, and preferences for the dissemination and implementation of evidence-based best practices. The results of the statewide needs assessment could also be used by others interested in disseminating best practices to primary care teams. METHODS: A cross-sectional survey was distributed electronically via REDCap (Research Electronic Data Capture; Vanderbilt University) to both Cardi-OH grant-funded and non-grant-funded members (ie, people who have engaged with Cardi-OH but are not funded by the grant). RESULTS: In total, 88% (103/117) of Cardi-OH grant-funded members and 8.14% (98/1204) of non-grant-funded members completed the needs assessment survey. Of these, 51.5% (53/103) of Cardi-OH grant-funded members and 47% (46/98) of non-grant-funded members provided direct clinical care. The top cardiovascular medicine and diabetes clinical topics for Cardi-OH grant-funded members (clinical and nonclinical) were lifestyle prescriptions (50/103, 48.5%), atypical diabetes (38/103, 36.9%), COVID-19 and cardiovascular disease (CVD; 38/103, 36.9%), and mental health and CVD (38/103, 36.9%). For non-grant-funded members, the top topics were lifestyle prescriptions (53/98, 54%), mental health and CVD (39/98, 40%), alcohol and CVD (27/98, 28%), and cardiovascular complications (27/98, 28%). Regarding social determinants of health, Cardi-OH grant-funded members prioritized 3 topics: weight bias and stigma (44/103, 42.7%), family-focused interventions (40/103, 38.8%), and adverse childhood events (37/103, 35.9%). Non-grant-funded members' choices were family-focused interventions (51/98, 52%), implicit bias (43/98, 44%), and adverse childhood events (39/98, 40%). Assessment of other risk factors for CVD and diabetes across grant- and non-grant-funded members revealed screening for social determinants of health in approximately 50% of patients in each practice, whereas some frequency of depression and substance abuse screening occurred in 80% to 90% of the patients. Access to best practice home monitoring devices was challenging, with 30% (16/53) and 41% (19/46) of clinical grant-funded and non-grant-funded members reporting challenges in obtaining home blood pressure monitoring devices and 68% (36/53) and 43% (20/46) reporting challenges with continuous glucose monitors. CONCLUSIONS: Cardi-OH grant- and non-grant-funded members shared the following high-priority topics: lifestyle prescriptions, CVD and mental health, family-focused interventions, alcohol and CVD, and adverse childhood experiences. Identifying high-priority educational topics and preferred delivery modalities for evidence-based materials is essential for ensuring that the dissemination of resources is practical and useful for providers.

Neuropathic Pain With and Without Diabetic Peripheral Neuropathy in Type 1 Diabetes.

OBJECTIVE: Diabetic peripheral neuropathy (DPN) is common; however, the features and burden of neuropathic pain (NP) in type 1 diabetes (T1D) are poorly understood. We evaluated the incidence of first occurrence, annual prevalence, remission, and risk factors for NP during long-term follow-up of participants with T1D. RESEARCH DESIGN AND METHODS: The Michigan Neuropathy Screening Instrument (MNSI) was administered annually (1994-2020) for 1,324 participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. NP with clinical signs of DPN (NP DPN+) was defined according to self-reported NP plus an examination score >2, while NP without clinical signs of DPN (NP DPN-) was defined according to self-reported NP and an examination score ≤2. RESULTS: At EDIC year 1, median age for participants was 36 years (interquartile range 30, 41), diabetes duration 13 years (10, 18), and HbA1c 7.9% (7.2, 8.9). At year 26 (median diabetes duration 39 years), cumulative incidence of NP was 57%, regardless of concomitant clinical signs of DPN (36% NP DPN+ vs. 46% NP DPN-). NP prevalence was 20% at 26 years (11% NP DPN+ and 9% NP DPN-), suggesting frequent remission. Annualized remission rates were similar regardless of pain medication use. In addition to HbA1c, female sex was associated with NP DPN-. CONCLUSIONS: NP incidence in T1D was high and frequently occurred in the absence of clinical signs of neuropathy, as assessed with the MNSI. Pain remission was not explained by pain medication use. Effective clinical strategies for identification and management are needed.

Major adverse events in youth-onset type 1 and type 2 diabetes: The SEARCH and TODAY studies.

AIMS: To determine contemporary incidence rates and risk factors for major adverse events in youth-onset T1D and T2D. METHODS: Participant interviews were conducted once during in-person visits from 2018 to 2019 in SEARCH (T1D: N = 564; T2D: N = 149) and semi-annually from 2014 to 2020 in TODAY (T2D: N = 495). Outcomes were adjudicated using harmonized, predetermined, standardized criteria. RESULTS: Incidence rates (events per 10,000 person-years) among T1D participants were: 10.9 ophthalmologic; 0 kidney; 11.1 nerve, 3.1 cardiac; 3.1 peripheral vascular; 1.6 cerebrovascular; and 15.6 gastrointestinal events. Among T2D participants, rates were: 40.0 ophthalmologic; 6.2 kidney; 21.2 nerve; 21.2 cardiac; 10.0 peripheral vascular; 5.0 cerebrovascular and 42.8 gastrointestinal events. Despite similar mean diabetes duration, complications were higher in youth with T2D than T1D: 2.5-fold higher for microvascular, 4.0-fold higher for macrovascular, and 2.7-fold higher for gastrointestinal disease. Univariate logistic regression analyses in T1D associated age at diagnosis, female sex, HbA1c and mean arterial pressure (MAP) with microvascular events. In youth-onset T2D, composite microvascular events associated positively with MAP and negatively with BMI, however composite macrovascular events associated solely with MAP. CONCLUSIONS: In youth-onset diabetes, end-organ events were infrequent but did occur before 15 years diabetes duration. Rates were higher and had different risk factors in T2D versus T1D.

Intensive Glycemic Management Is Associated With Reduced Retinal Structure Abnormalities on Ocular Coherence Tomography in the DCCT/EDIC Study.

OBJECTIVE: To investigate quantitative and qualitative changes in retinal structure using optical coherence tomography (OCT) and their associations with systemic or other risk factors in individuals with type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: In the Epidemiology of Diabetes Interventions and Complications (EDIC) study, OCT images were obtained during study years 25-28 (2019-2022) in 937 participants; 54% and 46% were from the original intensive (INT) and conventional (CONV) glycemic management treatment groups, respectively. RESULTS: Average age for participants was 61 years old, diabetes duration 39 years, and HbA1c 7.6%. Participants originally in the CONV group were more likely to have disorganization of retinal inner layers (DRIL) (CONV 27.3% vs. INT 18.7%; P = 0.0003), intraretinal fluid (CONV 24.4% vs. INT 19.2%; P = 0.0222), and intraretinal cysts (CONV 20.8% vs. INT 16.6%; P = 0.0471). In multivariable models, sex, age, smoking, mean updated systolic blood pressure, and history of "clinically significant" macular edema (CSME) and of anti-VEGF treatment were independently associated with changes in central subfield thickness, while HbA1c, BMI, and history of CSME and of ocular surgery were associated with DRIL. Visual acuity (VA) decline was associated with significant thinning of all retinal subfields except for the central and inner nasal subfields. CONCLUSIONS: Early intensive glycemic management in T1D is associated with a decreased risk of DRIL. This important morphological abnormality was associated with a history of macular edema, a history of ocular surgery, and worse VA. This study reveals benefits of intensive glycemic management on the retina beyond features detected by fundus photographs and ophthalmoscopy.

Plasma Biomarkers of Brain Injury and Their Association With Brain MRI and Cognition in Type 1 Diabetes.

OBJECTIVE: To evaluate associations between plasma biomarkers of brain injury and MRI and cognitive measures in participants with type 1 diabetes (T1D) from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. RESEARCH DESIGN AND METHODS: Plasma amyloid-ß-40, amyloid-ß-42, neurofilament light chain (NfL), phosphorylated Tau-181 (pTau-181), and glial fibrillary acidic protein (GFAP) were measured in 373 adults who participated in the DCCT/EDIC study. MRI assessments included total brain and white matter hyperintensity volumes, white matter mean fractional anisotropy, and indices of Alzheimer disease (AD)-like atrophy and predicted brain age. Cognitive measures included memory and psychomotor and mental efficiency tests and assessments of cognitive impairment. RESULTS: Participants were 60 (range 44-74) years old with 38 (30-51) years' T1D duration. Higher NfL was associated with an increase in predicted brain age (0.51 years per 20% increase in NfL; P < 0.001) and a 19.5% increase in the odds of impaired cognition (P < 0.01). Higher NfL and pTau-181 were associated with lower psychomotor and mental efficiency (P < 0.001) but not poorer memory. Amyloid-ß measures were not associated with study measures. A 1% increase in mean HbA1c was associated with a 14.6% higher NfL and 12.8% higher pTau-181 (P < 0.0001). CONCLUSIONS: In this aging T1D cohort, biomarkers of brain injury did not demonstrate an AD-like profile. NfL emerged as a biomarker of interest in T1D because of its association with higher HbA1c, accelerated brain aging on MRI, and cognitive dysfunction. Our study suggests that early neurodegeneration in adults with T1D is likely due to non-AD/nonamyloid mechanisms.

Diabetes Modulates Iodothyronine Deiodinase 2 Expression in the Mouse Retina: A Role for Thyroid Hormone in the Pathogenesis of Diabetic Retinopathy.

Purpose: Clinical investigations associate hypothyroidism with an increased risk for microvascular complications, yet the mechanism by which thyroid hormone regulates the development of diabetic retinopathy is not clearly understood. We investigated the role of iodothyronine deiodinase 2 (DIO2) in the pathogenesis of diabetic retinopathy. Methods: Retinas from streptozotocin-induced diabetic and nondiabetic mice were evaluated by RNA sequencing, RT-PCR, and immunostaining. Media and cell lysates from mouse retinal microvascular endothelial cells and retinal astrocytes exposed to physiologic (5 mM) and high glucose (25 mM) containing media were assessed by liquid chromatography-tandem mass spectrometry to measure tetraiodothyronine (T4) and tri-iodothyronine (T3) concentrations and by Western blot analysis to determine the relationship of T4/T3 to oxidative stress and inflammatory mediators. Cell death was determined by Trypan Blue exclusion assay. Results: At 12 weeks of diabetes duration, retinas from diabetic mice compared with nondiabetic mice demonstrated a significant decrease in Dio2 transcripts and Dio2 gene and protein (P < 0.05) expression. When cultured in the presence of high glucose, both mouse retinal astrocytes and microvascular endothelial cells demonstrated a significant reduction of DIO2 protein compared with cells cultured in physiologic glucose. High glucose inhibited generation of T3, leading to a significantly increased T4/T3 (P < 0.0079). Supplementation of cells with T3, but not T4, prevented the high glucose-induced rise in endothelial nitric oxide synthase, intercellular cell adhesion molecule 1, and endothelial cell death (P < 0.0079). Conclusions: Decreased intraretinal T3 owing to diabetes-induced loss of DIO2 may lead to dysfunction and death of cells in the retina, thereby contributing to the pathogenesis of early diabetic retinopathy.