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Background: The presence of vascular dysfunction is a well-recognized feature in youth with type 1 diabetes (T1D), accentuating their lifetime risk of cardiovascular events. Therapeutic strategies to mitigate vascular dysfunction are a high clinical priority. In the bromocriptine quick release T1D study (BCQR-T1D), we tested the hypothesis that BCQR would improve vascular health in youth with T1D. Methods: BCQR-T1D was a placebo-controlled, random-order, double-blinded, cross-over study investigating the cardiovascular and metabolic impact of BCQR in T1D. Adolescents in the BCQR-T1D study were randomized 1:1 to phase-1: 4 weeks of BCQR or placebo after which blood pressure and central aortic stiffness measurements by pulse wave velocity, relative area change, and distensibility from phase-contrast magnetic resonance imaging were performed. Following a 4-week washout period, phase 2 was performed in identical fashion with the alternate treatment. Results: Thirty-four adolescents (mean age 15.9±2.6 years, hemoglobin A1c 8.6±1.1%, body mass index percentile 71.4±26.1, median T1D duration 5.8 years) with T1D were enrolled and had magnetic resonance imaging data available. Compared with placebo, BCQR therapy decreased systolic (∆=−5 mmHg [95% CI, −3 to −7]; P P =0.039). BCQR reduced ascending aortic pulse wave velocity (∆=−0.4 m/s; P =0.018) and increased relative area change (∆=−2.6%, P =0.083) and distensibility (∆=0.08%/mmHg; P =0.017). In the thoraco-abdominal aorta, BCQR decreased pulse wave velocity (∆=−0.2 m/s; P =0.007) and increased distensibility (∆=0.05 %/mmHg; P =0.013). Conclusions: BCQR improved blood pressure and central and peripheral aortic stiffness and pressure hemodynamics in adolescents with T1D over 4 weeks versus placebo. BCQR may improve aortic stiffness in youth with T1D, supporting future longer-term studies.

Aims: To assess the effect of sodium-glucose cotransporter-2 inhibitor dapagliflozin on natriuresis, blood pressure (BP) and volume status in patients with chronic kidney disease (CKD) without diabetes. Materials and methods: We performed a mechanistic open-label study (DAPASALT) to evaluate the effects of dapagliflozin on 24-hour sodium excretion, 24-hour BP, extracellular volume, and markers of volume status during a standardized sodium diet (150 mmol/d) in six patients with CKD. In parallel, in a placebo-controlled double-blind crossover trial (DIAMOND), we determined the effects of 6 weeks of dapagliflozin on markers of volume status in 53 patients with CKD. Results: In DAPASALT (mean age 65 years, mean estimated glomerular filtration rate [eGFR] 39.4 mL/min/1.73 m2, median urine albumin:creatinine ratio [UACR] 111 mg/g), dapagliflozin did not change 24-hour sodium and volume excretion during 2 weeks of treatment. Dapagliflozin was associated with a modest increase in 24-hour glucose excretion on Day 4, which persisted at Day 14 and reversed to baseline after discontinuation. Mean 24-hour systolic BP decreased by −9.3 (95% confidence interval [CI] −19.1, 0.4) mmHg after 4 days and was sustained at Day 14 and at wash-out. Renin, angiotensin II, urinary aldosterone and copeptin levels increased from baseline. In DIAMOND (mean age 51 years, mean eGFR 59.0 mL/min/1.73 m2, median UACR 608 mg/g), compared to placebo, dapagliflozin increased plasma renin (38.5 [95% CI 7.4, 78.8]%), aldosterone (19.1 [95% CI −5.9, 50.8]%), and copeptin levels (7.3 [95% CI 0.1, 14.5] pmol/L). Conclusions: During a standardized sodium diet, dapagliflozin decreased BP but did not increase 24-hour sodium and volume excretion. The lack of increased natriuresis and diuresis may be attributed to activation of intra-renal compensatory mechanisms to prevent excessive water loss.

Early diabetic kidney disease (DKD) is common in young persons with type 1 (T1D) and type 2 diabetes (T2D) and accentuates their lifetime risk of kidney failure, requiring dialysis or a kidney transplant. Although clinical manifestations of DKD are similar in T1D and T2D, the structural lesions may differ, and it remains unclear whether DKD in T1D and T2D represent distinct diseases. Accordingly, the objective of this study is to build machine learning (ML) models using clinical and kidney MRI data to classify diabetes status, as well as structural and functional kidney differences of individuals with T1D versus T2D. We hypothesize that a highly accurate multimodal neural network can be constructed that integrates clinical and functional kidney MRI images.Data were obtained from several studies at University of Colorado in youth with T1D (n=102), T2D (n=91) as well as non-diabetic controls (n=60). A total of 253 participants were included in the analyses. First, we applied to clinical data (CASPER, IMPROVE-T2D, CROCODILE, and RENAL-HEIR trials) logistic regression and 7 ML models: extreme gradient boosting machine (XGBoost), XGBoost with grid search, k-nearest neighbors (KNN), support vector machine (SVM), decision tree, random forest, and a 3-layer neural network (NN-EHR). When a small subset of the clinical data was used as features, the NN-EHR yielded the highest accuracy of 84%. Next, we considered the MRI images (27,000 images from the 253 individuals). We applied three convoluted NN to perform the classification: AlexNet, VGG16, and a 4-layer Neural Network for Diabetes Detection (NN4DD). Considering the images alone, VGG16 and NN4DD both achieved an accuracy of > 80%. Additionally, by integrating the clinical data and the MRI images, the fusion neural network achieved an accuracy of almost 100%. Finally, an interpretability analysis of NN4DD indicated notable differences in kidney structure and function among the three groups.Although the cost of MRI is prohibitive and thus impractical for diabetes diagnosis, these results provide a proof-of-concept that fused neural networks that integrate multimodal data can be a valuable diagnostic tool, and provide structural and functional insight on kidney differences between T1D and T2D. This research is sponsored in part by the Natural Sciences and Engineering Council (Canada) and the National Institutes of Health (USA). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

INTRODUCTION: Diabetic kidney disease (DKD) is a leading cause of mortality in people with type 2 diabetes (T2D) and over 50% of individuals with youth-onset T2D will develop DKD as a young adult. Diagnosis of early-onset DKD remains a challenge in young persons with T2D secondary to a lack of available biomarkers for early DKD while the injuries may still be reversible. Furthermore, multiple barriers exist to initiate timely prevention and treatment strategies for DKD including a lack of Food and Drug Administration approval of medications in pediatrics; provider comfort with medication prescription, titration, and monitoring; and medication adherence. AREAS COVERED: Therapies that have promise for slowing DKD progression in youth with T2D include metformin, renin-angiotensin-aldosterone system inhibitors, glucagon-like peptide-1 receptor agonists, sodium glucose co-transporter 2 inhibitors, thiazolidinediones, sulfonylureas, endothelin receptor agonists, and mineralocorticoid antagonists. Novel agents are also in development to act synergistically on the kidneys with the aforementioned medications. We comprehensively review the available pharmacologic strategies for DKD in youth-onset T2D including mechanisms of action, potential adverse effects, and kidney-specific effects, with an emphasis on published pediatric and adult trials. EXPERT OPINION: Large clinical trials evaluating pharmacologic interventions targeting treatment of DKD in youth-onset T2D are strongly needed.

Objective: Type 2 diabetes (T2D) is a leading cause of end stage kidney disease (ESKD) worldwide. Recent studies suggest a more aggressive clinical course of diabetic kidney disease (DKD) in youth-onset than adult-onset T2D. We compared kidney structural lesions in youth- and adult-onset T2D to determine if youth-onset was associated with greater early tissue injury. Methods: Quantitative microscopy was performed on kidney tissue obtained from research kidney biopsies in 161 Pima Indians (117 women, 44 men) with T2D. Onset of T2D was established by serial oral glucose tolerance testing and participants were stratified as youth-onset ( Results: At biopsy, the 52 participants with youth-onset T2D were younger than the 109 with adult-onset T2D (39.1±9.9 vs. 51.4±10.2 years, pvs. 17.0±7.8 years, p=0.09). Median urine albumin-to-creatinine ratio was higher in the youth-onset group (58 [25th-75th percentile, 17-470] vs. 27 [13-73] mg/g, p=0.02). Youth-onset participants had greater glomerular basement membrane (GBM) width (552±128 nm vs. 490±114nm, p=0.002) and mesangial fractional volume (0.31±0.10 vs. 0.27±0.08, p=0.001) than adult-onset participants. Percentage glomerular sclerosis, glomerular volume, mesangial fractional volume, and GBM width were also inversely associated with age of diabetes onset as a continuous variable. Conclusion: Younger age of T2D onset strongly associates with more severe kidney structural lesions. Studies are underway to elucidate the pathways underlying these associations.

Concomitant type 2 diabetes and chronic kidney disease increases the risk of heart failure. Recent studies demonstrate beneficial effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on chronic kidney disease progression and heart failure hospitalization in patients with and without diabetes. In addition to inhibiting glucose reabsorption, SGLT2 inhibitors decrease proximal tubular sodium reabsorption, possibly leading to transient natriuresis. We review the hypothesis that SGLT2 inhibitor’s natriuretic and osmotic diuretic effects mediate their cardioprotective effects. The degree to which these benefits are related to changes in sodium, independent of the kidney, is currently unknown. Aside from effects on osmotically active sodium, we explore the intriguing possibility that SGLT2 inhibitors could also modulate nonosmotic sodium storage. This alternative hypothesis is based on emerging literature that challenges the traditional 2-compartment model of sodium balance to provide support for a 3-compartment model that includes the binding of sodium to glycosaminoglycans, such as those in muscles and skin. This recent research on nonosmotic sodium storage, as well as direct cardiac effects of SGLT2 inhibitors, provides possibilities for other ways in which SGLT2 inhibitors might mitigate heart failure risk. Overall, we review the effects of SGLT2 inhibitors on sodium balance and sensitivity, cardiac tissue, interstitial fluid and plasma volume, and nonosmotic sodium storage., Lay summary SGLT2 inhibitors have cardiovascular benefits that include HF outcomes in patients with and without diabetes. Because the underlying mechanisms are only partly explained by improvements in BP, body weight, or glucose control, other mechanisms have been proposed. We focus here on a central role for effects on sodium as underlying the positive benefits of SGLT2 inhibitors in HF. We explore the new (although still unconfirmed) idea that SGLT2 inhibitors exert some of their positive effects by affecting nonosmotic sodium (ie, sodium bound to muscles and skin and not dissolved in the blood). SGLT2 inhibitors have emerged as a class of drugs, previously prescribed for patients with T2D, that have in more recent years been shown to have substantial heart and kidney clinical benefits in patients with and without T2D.The degree to which these benefits are related to kidney-independent changes in sodium homeostasis is currently unknown.A better understanding of the nonosmotic mechanisms underpinning the benefits of SGLT2 inhibition on HF (with reduced or preserved left ventricular ejection fraction) may allow researchers to assess the effects of SGLT2 inhibitors in combination with other treatments that affect sodium balance.

Background: We compared plasma metabolites of amino acid oxidation and the tricarboxylic acid (TCA) cycle in youth with and without type 1 diabetes mellitus (T1DM) and related the metabolites to glomerular filtration rate (GFR), renal plasma flow (RPF), and albuminuria. Metabolites associated with impaired kidney function may warrant future study as potential biomarkers or even future interventions to improve kidney bioenergetics. Methods: Metabolomic profiling of fasting plasma samples using a targeted panel of 644 metabolites and an untargeted panel of 19,777 metabolites was performed in 50 youth with T1DM ≤ 10 years and 20 controls. GFR and RPF were ascertained by iohexol and p-aminohippurate clearance, and albuminuria calculated as urine albumin to creatinine ratio. Sparse partial least squares discriminant analysis and moderated t tests were used to identify metabolites associated with GFR and RPF. Results: Adolescents with and without T1DM were similar in age (16.1 ± 3.0 vs. 16.1 ± 2.9 years) and BMI (23.4 ± 5.1 vs. 22.7 ± 3.7 kg/m 2), but those with T1DM had higher GFR (189 ± 40 vs. 136 ± 22 ml/min) and RPF (820 ± 125 vs. 615 ± 65 ml/min). Metabolites of amino acid oxidation and the TCA cycle were significantly lower in adolescents with T1DM vs. controls, and the measured metabolites were able to discriminate diabetes status with an AUC of 0.82 (95% CI: 0.71, 0.93) and error rate of 0.21. Lower glycine (r:−0.33, q = 0.01), histidine (r:−0.45, q < 0.001), methionine (r: −0.29, q = 0.02), phenylalanine (r: −0.29, q = 0.01), serine (r: −0.42, q < 0.001), threonine (r: −0.28, q = 0.02), citrate (r: −0.35, q = 0.003), fumarate (r: −0.24, q = 0.04), and malate (r: −0.29, q = 0.02) correlated with higher GFR. Lower glycine (r: −0.28, q = 0.04), phenylalanine (r:−0.3, q = 0.03), fumarate (r: −0.29, q = 0.04), and malate (r: −0.5, q < 0.001) correlated with higher RPF. Lower histidine (r: −0.28, q = 0.02) was correlated with higher mean ACR. Conclusions: In conclusion, adolescents with relatively short T1DM duration exhibited lower plasma levels of carboxylic acids that associated with hyperfiltration and hyperperfusion. Trial registration: ClinicalTrials.gov NCT03618420 and NCT03584217 Graphical abstract: A higher resolution version of the Graphical abstract is available as Supplementary information [Figure not available: see fulltext.]

Sodium-glucose cotransporter-2 (SGLT2) inhibitors lower risk of cardiovascular and kidney events in people with type 2 diabetes. In the empagliflozin in type 1 diabetes clinical program (Empagliflozin as Adjunctive to inSulin thErapy [EASE]), glycemic control, body weight, and BP improved with

Objective: Glomerular injury is a recognized complication of diabetic ketoacidosis (DKA), yet the tubular lesions are poorly understood. The aim of this prospective study was to evaluate the presence and reversibility of tubular injury during DKA in children with type 1 diabetes (T1D). Research Design and Methods: Blood and urine samples were collected from 40 children with DKA (52% boys, mean age 11 ± 4 years, venous pH7.2 ± 0.1, glucose 451 ± 163 mg/dL) at three timepoints: 0–8 and 12–24 h after starting insulin, and 3 months after discharge. Mixed-effects models evaluated the changes in tubular injury markers over time (neutrophil gelatinase-associated lipocalin [NGAL], kidney injury molecule 1 [KIM-1], and interleukin 18 [IL-18]). We also evaluated the relationships among the tubular injury biomarkers, copeptin, a vasopressin surrogate, and serum uric acid (SUA). Results: Serum NGAL, KIM-1, and IL-18 were highest at 0–8h (306.5 ± 45.9ng/mL, 128.9 ± 10.1pg/mL, and 564.3 ± 39.2pg/mL, respectively) and significantly decreased over 3 months (p=0.03, p=0.01, and p < 0.001, respectively). There were strong relationships among increases in copeptin and SUA and rises in tubular injury biomarkers. At 0–8h, participants with acute kidney injury (AKI) [17%] showed significantly higher concentrations of tubular injury markers, copeptin, and SUA. Conclusions: DKA was characterized by tubular injury, and the degree of injury associated with elevated copeptin and SUA. Tubular injury biomarkers, copeptin and SUA may be able to predict AKI in DKA.

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

The worldwide prevalence of type 2 diabetes (T2D) is steadily increasing, and it remains a challenging public health problem for populations in both developing and developed countries around the world. Despite the recent advances in novel anti-diabetic agents, diabetic kidney disease (DKD) and cardiovascular disease (CVD) remain the leading causes of morbidity and mortality in T2D. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs), incretin hormones that stimulate post-prandial insulin secretion, serve as a promising avenue for treatment of T2D as they result in a variety of anti-hyperglycemic effects including increased endogenous insulin secretion, decreased gluconeogenesis, inhibition of pancreatic α-cell glucagon production, decreased pancreatic β-cell apoptosis, and increased β-cell proliferation. GLP-1RAs have also been found to delay gastric emptying, promote weight loss, increase satiety, decrease hypertension, improve dyslipidemia, reduce inflammation, improve albuminuria, induce natriuresis, improve cardiovascular function, and prevent thrombogenesis. In this review, we will present risk factors for the development of cardiac and kidney disease in individuals with T2D and discuss possible mechanisms for the cardiorenal protective effects seen with GLP-1RAs. We will also present the possibility of dual and tri-receptor agonist therapies with GLP-1, gastric inhibitory peptide, and glucagon RAs as an area of possible mechanistic synergy in the treatment of T2D and the prevention of cardiorenal complications.

Introduction Metabolic acidosis is associated with cardiovascular events, graft function, and mortality in kidney transplant recipients (KTRs). We examined the effect of alkali therapy on vascular endothelial function in KTRs. Methods We performed an 18-week, randomized, double-blind, placebo-controlled crossover pilot study examining the effect of sodium bicarbonate therapy versus placebo on vascular function in 20 adult KTRs at least 1 year from transplant with an estimated glomerular filtration rate (eGFR) ≥45 ml/min per 1.73 m2 and a serum bicarbonate level of 20 to 26 mEq/L. Each treatment period was 8 weeks in duration with a 2-week washout period between treatments. The primary outcome was change in brachial artery flow-mediated dilation (FMD) between sodium bicarbonate treatment and placebo. Results Twenty patients completed the study and were included in the primary analysis. The mean (SD) baseline eGFR of participants was 75 (22) ml/min per 1.73 m2, respectively. Serum bicarbonate levels did not increase significantly with treatment (0.3 [1.5] mEq/L, P = 0.37). Sodium bicarbonate therapy was not associated with worsening blood pressure, weight gain, or hypokalemia. There was no significant increase in FMD after 8 weeks of sodium bicarbonate therapy compared to placebo (mean change in FMD 2.2%, 95% CI –0.1 to 4.6, P = 0.06). There were no significant changes in high-sensitivity C-reactive protein, interleukin-6, eGFR, or urinary albumin-to-creatinine ratio during treatment. Urinary ammonium excretion decreased by 9 mmol/d (P=0.003), with sodium bicarbonate. Conclusions Sodium bicarbonate therapy is safe and feasible in KTRs, and our results strengthen the need for a larger randomized controlled trial., Graphical abstract

Hyperuricemia is common in chronic kidney disease (CKD) and may be present in 50% of patients presenting for dialysis. Hyperuricemia can be secondary to impaired glomerular filtration rate (GFR) that occurs in CKD. However, hyperuricemia can also precede the development of kidney disease and predict incident CKD. Experimental studies of hyperuricemic models have found that both soluble and crystalline uric acid can cause significant kidney damage, characterized by ischemia, tubulointerstitial fibrosis, and inflammation. However, most Mendelian randomization studies failed to demonstrate a causal relationship between uric acid and CKD, and clinical trials have had variable results. Here we suggest potential explanations for the negative clinical and genetic findings, including the role of crystalline uric acid, intracellular uric acid, and xanthine oxidase activity in uric acid-mediated kidney injury. We propose future clinical trials as well as an algorithm for treatment of hyperuricemia in patients with CKD.

Glomerular filtration rate (GFR) is a key measure of kidney function but often inaccurately ascertained by serum creatinine and cystatin C in pediatrics. In this pilot trial, we evaluated the relationship between GFR calculated by using phase-contrast MRI (PC-MRI) biomarkers and GFR byA total of twenty-one pediatric BMT candidates (8-21 years of age) were recruited for a research kidney PC-MRI. After completion ofThe GFR-MRI variables selected by elastic net included average heart rate during imaging (bpm), peak aorta flow below the kidney artery take-offs (ml/s), average kidney artery blood flow, average peak kidney vein blood flow, and average kidney vein blood flow (ml/s). The GFR-MRI model demonstrated strong agreement with GFR byIn this pilot study, noninvasive GFR-MRI showed strong agreement with gold standard GFR in youth scheduled for BMT. Further work is needed to evaluate whether non-contrast GFR-MRI holds promise to become a superior alternative to eGFR and GFR by clearance techniques. A higher resolution version of the Graphical abstract is available as Supplementary information.

The molecular mechanisms of SGLT2 inhibitors (SGLT2i) remain incompletely understood. Single-cell RNA sequencing and morphometrics data were collected from research kidney biopsies donated by participants with youth onset type 2 diabetes (T2D), aged 12-21 years of age, and healthy controls (HC) to study the effects of SGLT2i on kidney transcriptomics. Participants with T2D were more obese, had higher glomerular filtration rate, mesangial and glomerular volumes than HC. There were no clinically significant differences between participants prescribed SGLT2i (T2Di(+), n=10) and other T2D (T2Di(-), n=6). Transcriptional profiles showed SGLT2 expression exclusively in the proximal tubular (PT) cluster. Transcriptional alterations in T2Di(+) compared to T2Di(-) were seen across most nephron segments, most prominently in the distal nephron. SGLT2i treatment was associated with suppression of genes in the glycolysis, gluconeogenesis, tricarboxylic acid cycle pathways in PT, but enhanced expression in thick ascending limb. The energy sensitive mTOR signaling pathway transcripts were suppressed towards HC level in all nephron segments in T2Di(+). These transcriptional changes were confirmed in a diabetes mouse model treated with SGLT2i. Therefore, the beneficial effects of SGLT2i treatment to the kidneys might be from mitigating diabetes-induced metabolic perturbations via suppression of mTORC1 signaling across nephron segments, including those not expressing SGLT2.

Objective: We examined changes in the excretion of various amino acids and in glycolysis and ketogenesis-related metabolites, during and after diabetic ketoacidosis (DKA) diagnosis, in youth with known or new onset type 1 diabetes (T1D). Methods: Urine samples were collected from 40 youth with DKA (52% boys, mean age 11 ± 4 years, venous pH 7.2 ± 0.1, blood glucose 451 ± 163 mg/dL) at 3 time points: 0–8 h and 12–24 h after starting an insulin infusion, and 3 months after hospital discharge. Mixed-effects models evaluated the changes in amino acids and other metabolites in the urine. Results: Concentrations of urine histidine, threonine, tryptophan, and leucine per creatinine were highest at 0–8 h (148.8 ± 23.5, 59.5 ± 12.3, 15.4 ± 1.4, and 24.5 ± 2.4% of urine creatinine, respectively), and significantly decreased over 3 months (p = 0.028, p = 0.027, p = 0.019, and p < 0.0001, respectively). Urine histidine, threonine, tryptophan, and leucine per urine creatinine decreased by 10.6 ± 19.2, 0.7 ± 0.9, 1.3 ± 0.9, and 0.5 ± 0.3-fold, respectively, between 0 and 8 h and 3 months. Conclusions: In our study, DKA was associated with profound aminoaciduria, suggestive of proximal tubular dysfunction analogous to Fanconi syndrome.

TG concentrations across lipoprotein subclasses associate with diabetic kidney disease (DKD) in adults with T1D, but little is known about this relationship in youth with T1D. We evaluated cross-sectional relationships among TG concentrations across lipoprotein subclasses, intraglomerular hemodynamics, and renal oxygen availability (RO2) in youth with T1D. Glomerular filtration rate (GFR) , RO2, renal plasma flow (RPF) , afferent arteriolar resistance (RA) , efferent arteriolar resistance (RE) , intraglomerular pressure (PGLO) , and urine albumin-to-creatinine ratio (UACR) were assessed. Concentrations of lipid constituents from lipoprotein subclasses were quantified via targeted nuclear magnetic resonance spectroscopy (Nightingale Health Ltd., Helsinki, Finland) . Particle sizes for VLDL, LDL, intermediate-density lipoprotein, and HDL were measured. Fifty youth with T1D (age 16.0 ± 3.0 years, 50% female, HbA1c 8.7 ± 1.3%, T1D duration 5.7 ± 2.6 years) and 20 without T1D were included. VLDL-TG concentrations and small LDL-TG correlated with intraglomerular hemodynamic function parameters and RO2. To conclude, strong relationships were found among renal function markers and TG concentrations across lipoprotein subclasses in adolescents with T1D. Disclosure M.E.Pauley: None. K.L.Tommerdahl: None. C.Vinovskis: None. L.Pyle: None. R.Wadwa: Advisory Panel; Dompé, Consultant; Beta Bionics, Inc., Other Relationship; Tandem Diabetes Care, Inc., Research Support; Dexcom, Inc., Eli Lilly and Company, Tandem Diabetes Care, Inc. R.G.Nelson: None. K.J.Nadeau: None. P.Bjornstad: Advisory Panel; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Horizon Therapeutics plc, LG Chem, Lilly, Novo Nordisk, Consultant; AstraZeneca, Bristol-Myers Squibb Company. Funding MEP supported by NIH (T32DK063687) ; KLT supported by NIH (K23 HL159292) , Children’s Hospital Colorado Research Institute Research Scholar Award, University of Colorado Diabetes Research Center (P30 DK116073) , Ludeman Family Center for Women’s Health Research at the University of Colorado, and Dept of Pediatrics, Section of Endocrinology at University of Colorado School of Medicine; PB supported by NIDDK (RDK129211, R21 DK129720, K23 DK116720, UC DK114886, and P30 DK116073) , JDRF (2-SRA-2019-845-S-B, 3-SRA-2017-424-M-B, 3-SRA-2022-1097-M-B) , Boettcher Foundation, American Heart Association (20IPA35260142) , Ludeman Family Center for Women’s Health Research at the University of Colorado, Department of Pediatrics, Section of Endocrinology and Barbara Davis Center for Diabetes at University of Colorado School of Medicine

Standardization of GFR by BSA can underestimate kidney function in overweight individuals. Standardization of GFR by ECV, rather than BSA, may be a way to avoid measurement bias. Our aim was to compare the distribution and agreement of GFR measures in people with type 1 diabetes at risk of kidney disease, and to determine associations with clinical hemodynamic measures. In this exploratory analysis of the PERL clinical trial of allopurinol, the distribution and agreement of 4 measurements for GFR were compared in 542 participants with eligible data. GFR was measured using gold-standard iohexol plasma clearance procedures, and ECV was calculated using the Jødal-Bröchner-Mortensen method, which estimates ECV using results from clearance studies. GFR was standardized using ECV corrected for 14 L of fluid volume rather than 1.73 m2 of BSA. Agreement between measurements was assessed by Bland-Altman and Spearman correlation analyses. The trial primary outcome was re-analyzed using ECV-adjusted GFR. Mean age and BMI were 51±years and 29.5±6.0 kg/m2. The distribution of normalized GFR measures overlapped and agreement was strong; GFR/ECV overestimated GFR/BSA by 2.9 numerical units (mean 70.5 ml/min/14 L vs. 67.6 ml/min/1.73 m2) . Heart rate was associated with unstandardized GFR (r=-0.10, p=0.023) . Associations between diastolic blood pressure and all measures of GFR were observed (r ranged from 0.17-0.18; p-values Disclosure L.Lovblom: None. R.Pop-busui: Advisory Panel; Averitas Pharma, Inc., Boehringer Ingelheim International GmbH, Nevro Corp., Novo Nordisk, Reata Pharmaceuticals, Inc., Regenacy Pharmaceuticals, Inc. S.Polsky: Advisory Panel; Medtronic, Other Relationship; diaTribe, Research Support; Dexcom, Inc., Eli Lilly and Company, Leona M. and Harry B. Helmsley Charitable Trust, Medtronic, National Institute of Diabetes and Digestive and Kidney Diseases, Sanofi-Aventis U.S. A.B.Karger: Consultant; Roche Diagnostics, Research Support; Kyowa Kirin Co., Ltd., Siemens. A.Galecki: None. B.A.Perkins: Advisory Panel; Abbott Diabetes, Insulet Corporation, Sanofi, Board Member; Novo Nordisk, Other Relationship; Abbott Diabetes, Insulet Corporation, Medtronic, Novo Nordisk, Research Support; BMO Bank of Montreal, Novo Nordisk. D.Cherney: Other Relationship; AbbVie Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Janssen Research & Development, LLC, Lilly, Maze, BMS, CSL-Behring, Merck, Otsuka, Novartis and Novo-Nordisk , Mitsubishi Tanabe Pharma Corporation, Sanofi, Research Support; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca and Novo-Nordisk. S.O.Lanctot: Employee; Medtronic. D.M.Maahs: Advisory Panel; Abbott Diabetes, Eli Lilly and Company, Medtronic, Novo Nordisk, Sanofi, Consultant; Aditx Therapeutics, Inc., Biospex. P.Bjornstad: Advisory Panel; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Horizon Therapeutics plc, LG Chem, Lilly, Novo Nordisk, Consultant; AstraZeneca, Bristol-Myers Squibb Company. M.Mauer: None. L.Caramori: Advisory Panel; Bayer AG, Consultant; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk, Research Support; Bayer AG, Novartis AG. S.Rosas: Advisory Panel; AstraZeneca, Teladoc Health, Other Relationship; Bayer AG, Research Support; AstraZeneca, Bayer AG. P.Rossing: Consultant; Astellas Pharma Inc., AstraZeneca, Bayer AG, Gilead Sciences, Inc., Merck Sharp & Dohme Corp., Novo Nordisk A/S, Sanofi, Speaker's Bureau; Eli Lilly and Company. K.R.Tuttle: Advisory Panel; Boehringer Ingelheim International GmbH, Gilead Sciences, Inc., Consultant; AstraZeneca, Eli Lilly and Company, Research Support; Bayer AG, Goldfinch Bio, Inc., Novo Nordisk, Travere. Funding Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; PERL ClinicalTrials.gov number, NCT02017171

Our objective was to compare renal hemodynamic function between obese youth with and without type 2 diabetes (T2D) and relate these measures to adipose insulin resistance (IR) . We assessed insulin sensitivity and kidney function in obese youth with (n=31, 15.8 ± 1.8 years, BMI 35.6 ± 6.6 kg/m2) , and without (n=20, 15.3 ± 2.1 years, BMI 38.2 ± 7.4 kg/m2) T2D. A hyperglycemic clamp was performed with 20% dextrose to maintain mild hyperglycemia for 240 minutes. Free fatty acids (FFA) were measured at baseline and every minutes during the steady state. FFA suppression (baseline FFA subtracted from steady state FFA) was used to estimate adipose IR. Iohexol and p-aminohippurate clearances were used to measure GFR and renal plasma flow, respectively. Renal hemodynamic parameters were calculated using Gomez equations. FFA suppression was attenuated in youth with T2D compared to obese controls (55.6% vs. 92.1%, p Youth with T2D had impaired FFA suppression compared to obese controls, indicating adipose IR. Impaired FFA suppression was associated with perturbed renal hemodynamics, indicating a potential role for adipose IR in the development of early diabetic kidney disease. Disclosure C.Platnick: None. P.V.Prasad: None. L.Li: None. L.Pyle: None. R.G.Nelson: None. D.Van raalte: Advisory Panel; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck & Co., Inc., Sanofi, Research Support; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck & Co., Inc., Sanofi. K.J.Nadeau: None. P.Bjornstad: Advisory Panel; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Horizon Therapeutics plc, LG Chem, Lilly, Novo Nordisk, Consultant; AstraZeneca, Bristol-Myers Squibb Company.

Background: Global vascular dysfunction is well-recognized in youth with type 1 diabetes (T1D) , accentuating lifetime cardiovascular event risk and making therapeutic strategies to mitigate vascular dysfunction a high priority. In the BCQR-T1D study, we tested the hypothesis that BCQR, a medication used in obese adults with type 2 diabetes, would improve vascular health in T1D youth. Methods: BCQR-T1D was a placebo-controlled, random-order, double-blinded, cross-over study investigating cardiovascular and metabolic impacts of BCQR in T1D. Youth were randomized 1:1 to phase-1: 4-weeks of BCQR or placebo after which blood pressure (BP) , peripheral vascular stiffness by brachial artery distensibility (BrachD) , and central aortic stiffness by pulse wave velocity (PWV) , relative area change (RAC) and distensibility from phase-contrast MRI, were performed. Following a 4-week washout period, phase 2 was performed in identical fashion with the alternate treatment. Results: Forty-two adolescents (mean age 15.9 years, HbA1c 8.6%, BMI %ile 71.4, T1D duration 5.8 years) with T1D were enrolled. Compared to placebo, BCQR therapy decreased systolic (∆ = -5 mmHg, p Conclusions: BCQR improved BP, central and peripheral aortic stiffness and pressure hemodynamics in T1D adolescents over 4 weeks vs. placebo, even if normal weight, supporting future longer-term studies. Disclosure M.Schäfer: None. I.E.Schauer: None. K.J.Nadeau: None. L.Browne: None. U.Truong: None. P.Bjornstad: Advisory Panel; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Horizon Therapeutics plc, LG Chem, Lilly, Novo Nordisk, Consultant; AstraZeneca, Bristol-Myers Squibb Company. J.K.Snell-bergeon: Stock/Shareholder; GlaxoSmithKline plc. A.Baumgartner: None. K.S.Hunter: None. J.Reusch: Advisory Panel; Medtronic. A.J.Barker: None. Funding JDRF BROM QR THERP3-SRA-2015-125-M-R

OBJECTIVE Insulin resistance and obesity are independently associated with type 1 diabetes (T1D) and are known risk factors for cardiovascular and kidney diseases, the leading causes of death in T1D. We evaluated the effect of BMI on cardiovascular and kidney outcomes in youth with T1D versus control youth with normal weight or obesity and youth with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Pubertal youth (n = 284) aged 12–21 years underwent assessments of resting heart rate (RHR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), leptin, hs-CRP, adiponectin, ratio of urine albumin to creatinine, and estimated glomerular filtration rate. Participants with T1D underwent bicycle ergometry for VO2peak, monitoring for peripheral brachial artery distensibility (BAD), endothelial function testing for reactive hyperemic index, and aortic MRI for central arterial stiffness or shear. RESULTS In adolescents with T1D, RHR, SBP, DBP, mean arterial pressure, leptin, hs-CRP, and hypertension prevalence were significantly higher, and BAD, descending aorta pulse wave velocity, and VO2peak lower with an obese versus normal BMI. Although hypertension prevalence and RHR were highest in obese adolescents with T1D and adiponectin lowest in youth with T2D, other measures were similar between obese adolescents with T1D and those with T2D. CONCLUSIONS Obesity, now increasingly prevalent in people with T1D, correlates with a less favorable cardiovascular and kidney risk profile, nearly approximating the phenotype of youth with T2D. Focused lifestyle management in youth-onset T1D is critically needed to reduce cardiovascular risk.

Youth with type 1 diabetes (T1D) demonstrate insulin resistance, independently of glycaemia, when compared to normoglycaemic peers. Insulin resistance increases the risk of cardiovascular disease and diabetic kidney disease, factors also associated with systemic inflammation. We evaluated the effect of metformin on markers of inflammation and diabetic kidney disease in adolescents with T1D. EMERALD, a double-blind, randomized, placebo-controlled trial of 3 months of metformin in 48 participants aged 12-21 years with T1D, included baseline and follow-up assessments of serum creatinine and cystatin C to estimate glomerular filtration rate (eGFR), aspartate aminotransferase, alanine aminotransferase, high-sensitivity C-reactive protein, white blood count, platelets, adiponectin, leptin, and urine albumin: creatinine ratio (UACR). Metformin was associated with a 13.9 mL/min/1.73 m2 (95% confidence interval 4.7-23.1 mL/min/1.73 m2 ) increase in estimated GFR by serum creatinine versus placebo (P ≤ 0.01), with a significant difference remaining after multivariable adjustments (P = 0.03). Whereas eGFR measured by serum creatinine increased significantly after metformin treatment, no differences were observed in cystatin C, UACR, or systemic inflammatory markers. Additional studies with directly measured GFR in response to metformin in T1D are needed.

Glucagon-like peptide (GLP)-1 receptor agonists are the cornerstone in the treatment of hyperglycemia in many people suffering from type 2 diabetes (T2D). These drugs have potent glucose-lowering actions and, additionally, lower body weight through satiety induction while reducing blood pressure and dyslipidemia. Partly through these actions, GLP-1 receptor agonism was shown to reduce cardiovascular disease (CVD) in people with T2D with previous CVD or at high-risk thereof. In these cardiovascular safety trials, in secondary or exploratory analyses, GLP-1 receptor agonists were also shown to reduce macro-albuminuria, an accepted surrogate marker for diabetic kidney disease (DKD), a condition that still represents a major unmet medical need. In this review we will discuss the evidence which suggests renoprotection induced by GLP-1 receptor agonists and the potential mechanisms that may be involved. These include mitigation of hyperglycemia, overweight and insulin resistance, systemic and glomerular hypertension, dyslipidemia, sodium retention, inflammation and renal hypoxia. The recently initiated large-sized FLOW trial investigating the effects of semaglutide on hard renal outcomes in patients with DKD will provide clarity whether GLP-1 receptor agonists may reduce the burden of DKD in addition to their other beneficial metabolic and cardiovascular effects.

We report a case of a patient who developed dialysis-requiring acute kidney injury (AKI) after the use of canagliflozin. A 66-year-old man with type 2 diabetes who was recovering from left knee septic arthritis at a rehabilitation facility was admitted with oliguric AKI 5 days after starting treatment with canagliflozin, an inhibitor of sodium/glucose cotransporter 2 (SGLT2). The patient presented with hematuria, non-nephrotic-range proteinuria, and serum creatinine level of 6.8 (baseline, 1.1-1.3) mg/dL. There was no recent use of radiocontrast agents or exposure to other nephrotoxins. The patient subsequently required hemodialysis. Due to recent antibiotic use (ampicillin-sulbactam), acute interstitial nephritis was considered in the differential diagnosis. Kidney biopsy was performed, which showed the presence of osmotic nephropathy. The patient's kidney function returned to baseline after 2 weeks of hemodialysis. This case provides evidence of an association of osmotic nephropathy with the use of canagliflozin and discusses potential mechanisms. We recommend kidney biopsy for cases of severe AKI associated with SGLT2 inhibitors to better understand the relationship of this complication with the use of this class of medications.

Bariatric surgery improves markers of kidney health in severe obesity, yet it is unclear if kidney disease outcomes differ according to age at surgery. Therefore, we examined health effects of Roux-en-Y gastric bypass between 161 adolescents and 396 adults participating in two related but distinct studies. Primary outcomes were elevated urine albumin-to-creatinine ratio (UACR) of 30mg/g or more and hyperfiltration (an estimated glomerular filtration rate of 135 ml/min/1.73m(2) or more). Analyses were stratified by the presence of pre-operative type 2 diabetes. Adolescents with pre-operative type 2 diabetes had a significantly increased prevalence of elevated UACR prior to surgery compared to adults (22.5 vs. 9.0%). Resolution of elevated UACR following surgery differed between adolescents and adults with type 2 diabetes, with adolescents experiencing a significantly earlier improvement following surgery. Adolescents without pre-operative type 2 diabetes demonstrated a significantly increased prevalence of UACR prior to surgery compared to adults (9.4 vs. 4.5%), with no improvement occurring in either group post-operatively. Adolescents with pre-operative type 2 diabetes had a significantly increased prevalence of hyperfiltration that remained throughout the study period, whereas hyperfiltration prevalence was similar among those without type 2 diabetes. Thus, adolescents with pre-operative type 2 diabetes experienced earlier attenuation of elevated UACR compared to adults with pre-operative type 2 diabetes in response to gastric bypass. TRIAL REGISTRATION: (ClinicalTrials.gov NCT00465829 and NCT00474318

The association between increased serum urate and hypertension has been a subject of intense controversy. Extracellular uric acid drives uric acid deposition in gout, kidney stones, and possibly vascular calcification. Mendelian randomization studies, however, indicate that serum urate is likely not the causal factor in hypertension although it does increase the risk for sudden cardiac death and diabetic vascular disease. Nevertheless, experimental evidence strongly suggests that an increase in intracellular urate is a key factor in the pathogenesis of primary hypertension. Pilot clinical trials show beneficial effect of lowering serum urate in hyperuricemic individuals who are young, hypertensive, and have preserved kidney function. Some evidence suggest that activation of the renin–angiotensin system (RAS) occurs in hyperuricemia and blocking the RAS may mimic the effects of xanthine oxidase inhibitors. A reduction in intracellular urate may be achieved by lowering serum urate concentration or by suppressing intracellular urate production with dietary measures that include reducing sugar, fructose, and salt intake. We suggest that these elements in the western diet may play a major role in the pathogenesis of primary hypertension. Studies are necessary to better define the interrelation between uric acid concentrations inside and outside the cell. In addition, large-scale clinical trials are needed to determine if extracellular and intracellular urate reduction can provide benefit hypertension and cardiometabolic disease.

BACKGROUND AND AIMS Approximately 40% of people with type 2 diabetes (T2D) develop chronic kidney disease (CKD) and, despite current treatment, T2D is the most common cause of progression to kidney failure. This situation underscores the need for additional pharmacotherapeutic options. Analyses of cardiovascular outcomes trials suggest that glucagon-like peptide-1 receptor agonists (GLP-1RAs), such as semaglutide, lower albuminuria and attenuate estimated glomerular filtration rate (eGFR) decline in people with T2D. Previous analyses suggest that GLP-1RAs reduce hypoxia and inflammation and, thereby, have a mode of action on the kidneys that is distinct from other treatments, such as sodium-glucose cotransporter-2 (SGCT-2) inhibitors and renin–angiotensin–aldosterone system (RAAS) blockers. Furthermore, the primary benefit of semaglutide appears to be in people with an eGFR < 60 mL/min/1.73 m2, a group in which there is a significant residual risk of progression and a consequent unmet need for effective treatment. To gain further insights on the kidney-protective mechanism of action of semaglutide, the REMODEL trial is integrating investigative functional kidney magnetic resonance imaging (MRI) and kidney biopsies; recent developments in these techniques permit elucidation of the mechanisms underlying kidney protection with current therapies. Mechanistic findings of the REMODEL trial will complement those of the ongoing FLOW clinical trial, which is designed to evaluate clinical outcomes in people with T2D and CKD treated with once-weekly (OW) subcutaneous semaglutide. METHOD REMODEL (NCT04865770) is a 52-week, multicentre, international clinical trial (Figure 1). Primary endpoints are MRI-based and include change from baseline to week 52 in kidney oxygenation (measured with BOLD MRI R2*), global kidney perfusion (phase-contrast MRI) and kidney inflammation (T1 Mapping MRI). Secondary endpoints evaluated from kidney biopsies in a nested cohort (n ∼ 45) include change from baseline to week 52 in intrarenal mRNA expression, assessed by single-nucleus transcriptomics and glomerular basement membrane width, assessed by morphometry. Other secondary endpoints include the apparent diffusion coefficient (estimating renal fibrosis; evaluated with diffusion-weighted MRI), natriuresis, albumin excretion rate and creatinine clearance. MRI outcomes will also be evaluated at week 4 to identify potential early effects of semaglutide in the kidney. Examples of MRI and kidney biopsy single-cell gene expression profile data from participants with CKD are shown in Figure 2 (data not from REMODEL). Safety will be assessed throughout the trial. RESULTS REMODEL was initiated in April 2021 and is being conducted in Canada, France, Italy, Poland, South Africa, Spain and USA. CONCLUSION REMODEL will investigate the effect of the GLP-1RA semaglutide on inflammatory and hypoxia-related pathways in the kidney. The combination of MRI and tissue-level interrogation with biopsies will complement standard laboratory findings, enabling the identification of cells and pathways involved in kidney disease and protection. The trial will provide valuable mechanistic insights on the use of OW semaglutide in people with T2D and CKD and may stimulate the development of a precision medicine approach to the management of such individuals. In addition, REMODEL will complement the findings of the FLOW trial.

Background and objectives Sodium-glucose transporter 2 (SGLT2) inhibitor–induced uric acid lowering may contribute to kidney-protective effects of the drug class in people with type 2 diabetes. This study investigates mechanisms of plasma uric acid lowering by SGLT2 inhibitors in people with type 2 diabetes with a focus on urate transporter 1. Design, setting, participants, & measurements We conducted an analysis of two randomized clinical trials. First, in the Renoprotective Effects of Dapagliflozin in Type 2 Diabetes study, 44 people with type 2 diabetes were randomized to dapagliflozin or gliclazide for 12 weeks. Plasma uric acid, fractional uric acid excretion, and hemodynamic kidney function were measured in the fasted state and during clamped euglycemia or hyperglycemia. Second, in the Uric Acid Excretion study, ten people with type 2 diabetes received 1 week of empagliflozin, urate transporter 1 blocker benzbromarone, or their combination in a crossover design, and effects on plasma uric acid, fractional uric acid excretion, and 24-hour uric acid excretion were measured. Results In the Renoprotective Effects of Dapagliflozin in Type 2 Diabetes study, compared with the fasted state (5.361.1mg/dl),acutehyperinsulinemiaandhyperglycemiasignificantly reduced plasma uric acid by 0.260.3 and 0.460.3 mg/dl (both P,0.001) while increasing fractional uric acid excretion (by 3.2%63.1% and 8.9%64.5%, respectively; both P,0.001). Dapagliflozin reduced plasma uric acid by 0.860.8 during fasting, 1.061.0 in hyperinsulinemic-euglycemic state, and 0.860.7 mg/dl during hyperglycemic conditions (P,0.001), respectively, whereas fractional uric acid excretion in 24-hour urine increased by 3.0%62.1% (P,0.001) and 2.6%64.5% during hyperinsulinemic-euglycemic conditions (P=0.003). Fractional uric acid excretion strongly correlated to fractional glucose excretion (r=0.35; P=0.02). In the Uric Acid Excretion study, empagliflozin and benzbromarone both significantly reduced plasma uric acid and increased fractional uric acid excretion. Effects of combination therapy did not differ from benzbromarone monotherapy. Conclusions In conclusion, SGLT2 inhibitors induce uric acid excretion, which is strongly linked to urinary glucose excretion and is attenuated during concomitant pharmacologic blockade of urate transporter 1. Clinical Trial registry name and registration number: Renoprotective Effects of Dapagliflozin in Type 2 Diabetes (RED), NCT02682563; SGLT2 Inhibition: Uric Acid Excretion Study (UREX), NCT05210517.

Endothelial glycocalyx; Glomerular endothelial cell; Minimal change disease Glicocàlix endotelial; Cèl·lula endotelial glomerular; Malaltia de canvis mínims Glicocálix endotelial; Célula endotelial glomerular; Enfermedad de cambios mínimos Introduction Minimal change disease (MCD) is considered a podocyte disorder triggered by unknown circulating factors. Here, we hypothesized that the endothelial cell (EC) is also involved in MCD. Methods We studied 45 children with idiopathic nephrotic syndrome (44 had steroid sensitive nephrotic syndrome [SSNS], and 12 had biopsy-proven MCD), 21 adults with MCD, and 38 healthy controls (30 children, 8 adults). In circulation, we measured products of endothelial glycocalyx (EG) degradation (syndecan-1, heparan sulfate [HS] fragments), HS proteoglycan cleaving enzymes (matrix metalloprotease-2 [MMP-2], heparanase activity), and markers of endothelial activation (von Willebrand factor [vWF], thrombomodulin) by enzyme-linked immunosorbent assay (ELISA) and mass spectrometry. In human kidney tissue, we assessed glomerular EC (GEnC) activation by immunofluorescence of caveolin-1 (n = 11 MCD, n = 5 controls). In vitro, we cultured immortalized human GEnC with sera from control subjects and patients with MCD/SSNS sera in relapse (n = 5 per group) and performed Western blotting of thrombomodulin of cell lysates as surrogate marker of endothelial activation. Results In circulation, median concentrations of all endothelial markers were higher in patients with active disease compared with controls and remained high in some patients during remission. In the MCD glomerulus, caveolin-1 expression was higher, in an endothelial-specific pattern, compared with controls. In cultured human GEnC, sera from children with MCD/SSNS in relapse increased thrombomodulin expression compared with control sera. Conclusion Our data show that alterations involving the systemic and glomerular endothelium are nearly universal in patients with MCD and SSNS, and that GEnC can be directly activated by circulating factors present in the MCD/SSNS sera during relapse.

To evaluate changes in retinal thickness and morphology using OCT in youth with type 2 diabetes (T2D) and to identify systemic biomarkers correlating with these changes.Retrospective subgroup analysis of a prospective study.Participants who underwent OCT imaging in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) trial and its follow-up study TODAY2.In 2010-2011 (TODAY) and 2017-2018 (TODAY2), 6 × 6-mm macular volume OCT scans were acquired, segmented, and analyzed to generate total retinal thickness, inner retinal thickness, and outer retinal thickness. The main retinal morphologies graded were intraretinal cystoid spaces, subretinal fluid, and posterior vitreous detachment (PVD).Changes in total and individual retinal layer thickness and development of abnormal vitreomacular morphology between TODAY and TODAY2.Participants had a mean age of 17.9 ± 2.4 years and glycated hemoglobin (HbA1c) of 8.2 ± 2.8% in TODAY and a mean age of 25.0 ± 2.4 years and mean HbA1c of 9.5 ± 2.8% in TODAY2. Longitudinally between assessments, there were overall decreases in outer retinal thickness from 167.2 ± 11.5 microns to 158.4 ± 12.8 microns (Youth with T2D develop retinal thickness changes on OCT, including increases in total retinal and inner retinal thickness in the center subfield that correlate with HbA1c and fasting glucose, respectively. Taken together with the increased prevalence of abnormal vitreomacular morphology in this cohort at risk, these findings emphasize the importance of controlling risk factors to prevent the development of sight-threatening retinal complications.

Aims: Glomerular hyperfiltration plays a key role in the pathophysiology of diabetic kidney disease (DKD). Mechanisms underlying this adverse hemodynamic profile are incompletely understood. We hypothesized that systemic vascular pathology, including endothelial dysfunction and arterial stiffness, relates to glomerular hyperfiltration indicated by filtration fraction (FF). Methods: Baseline data of three trials of overweight adults with type 2 diabetes (TD2, n = 111) with relatively well preserved kidney function were analyzed. Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and FF, were assessed with gold-standard clearance techniques. Systemic vascular resistance (SVR), an indicator of endothelial dysfunction, and pulse pressure (PP), a measure of arterial stiffness, were derived from continuous beat-to-beat monitoring. Results: SVR related negatively to GFR (β: −0.382, p < 0.001) and ERPF (β: −0.475, p < 0.001), and positively to FF (β:0.369, p < 0.001). Associations between SVR, ERPF and FF persisted after multivariable adjustments. PP was negatively related to ERPF (β: −0.252, p = 0.008), and positively to FF (β: 0.257, p = 0.006), of which the latter remained significant in multivariable regression. Conclusion: Parameters of systemic vascular pathology, including endothelial dysfunction and arterial stiffness, relate to an adverse kidney hemodynamic profile characterized by glomerular hyperfiltration, which predisposes to the development of DKD.

Background: Early identification of youth with type 1 diabetes (T1D) at risk for diabetic kidney disease may improve clinical outcomes. We examined the cross-sectional relationship between kidney biomarkers neutrophil gelatinase–associated lipocalin (NGAL), copeptin, interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), chitinase-3-like protein-1 (YKL-40), and monocyte chemoattractant protein-1 (MCP-1) and intrarenal hemodynamic function in adolescents with T1D. Methods: Urine albumin-to-creatinine ratio (UACR), renal vascular resistance (RVR), glomerular filtration rate (GFR), intraglomerular pressure (P GLO), efferent arteriole resistance (R E), afferent arteriolar resistance (R A), and renal plasma flow (RPF), and the above indicated biomarkers were assessed in youth aged 12–21 years with and without T1D of < 10 years duration. Results: Fifty adolescents with T1D (16.1 ± 3.0 years, HbA1c 8.6 ± 1.2%) and 20 adolescents of comparable BMI without T1D (16.1 ± 2.9 years, HbA1c 5.2 ± 0.2%) were enrolled. Adolescents with T1D demonstrated significantly higher GFR, RPF, R E, and P GLO than controls (39%, 33%, 74%, and 29%, respectively, all p < 0.0001). Adolescents with T1D also exhibited significantly lower RVR and R A than controls (25% and 155%, respectively, both p < 0.0001). YKL-40 and KIM-1 concentrations, respectively, were positively associated with GFR (r: 0.43, p = 0.002; r: 0.41, p = 0.003), RPF (r: 0.29, p = 0.08; r: 0.34, p = 0.04), UACR (r: 0.33, p = 0.02; r: 0.50, p = 0.0002), and P GLO (r: 0.45, p = 0.006; r: 0.52, p = 0.001) in adolescents with T1D. Conclusions: Higher concentrations of biomarkers YKL-40 and KIM-1 may help define the risk for intraglomerular hemodynamic dysfunction in youth with T1D. Graphical abstract: A higher resolution version of the Graphical abstract is available as Supplementary information. [Figure not available: see fulltext.]

OBJECTIVES/GOALS: The goal of this study is to investigate the potential independent relationship between epicardial adipose tissue (EAT) and cardiometabolic health in youth-onset type 2 diabetes (T2D) and explore changes in EAT as a potential mediator of changes in cardiometabolic health in response to vertical sleeve gastrectomy (VSG). METHODS/STUDY POPULATION: We will assess glycemic control, insulin sensitivity and secretion in youth with T2D before and 3 months after VSG. Fasting labs, anthropometrics, and a 4-hour, frequently sampled liquid mixed meal tolerance test (45g carbohydrates, 14g fat, and 14g protein) were performed. Calculations included glucose, insulin, and GLP-1 area under the curve (AUC), Matsuda Index, HOMA-IR, and oral disposition index (DI). These cardiometabolic outcomes will then be assessed for associations between total EAT volume, measured from cardiac MRI. RESULTS/ANTICIPATED RESULTS: Previous studies have shown that individuals with obesity have higher EAT than lean controls, and adults with T2D have even higher EAT than obese controls. Therefore, we anticipate that our participants will have higher volume of EAT than what has been reported in the literature and that they will have worsening cardiometabolic outcomes without MBS. Our anticipated results will include: Weight and BMI, hemoglobin A1c, diabetes medications, Matsuda Index, HOMA-IR, DI, and glucose and insulin AUC during an MMTT. Cardiac MRI's are being analyzed and will give total EAT volume and will be analyzed for correlations with the cardiometabolic outcomes of body composition, aortic stiffness, blood pressure, cardiac structure and function, as well as lipid panel and insulin sensitivity. DISCUSSION/SIGNIFICANCE: This study is the first to specifically assess EAT in adolescents with T2D. The assessment of EAT will be done with gold-standard MRI and correlated with cardiometabolic health assessed by gold-standard methods. Together, the results will give insight into EAT as a potential independent cardiometabolic risk factor in adolescents undergoing VSG.

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

Hyperfiltration is a state of high glomerular filtration rate (GFR) observed in early diabetes that damages glomeruli, resulting in an iterative process of increasing filtration load on fewer and fewer remaining functional glomeruli. To delineate underlying cellular mechanisms of damage associated with hyperfiltration, transcriptional profiles of kidney biopsies from Pima Indians with type 2 diabetes with or without early-stage diabetic kidney disease were grouped into two hyperfiltration categories based on annual iothalamate GFR measurements. Twenty-six participants with a peak GFR measurement within two years of biopsy were categorized as the hyperfiltration group, and 26 in whom biopsy preceded peak GFR by over two years were considered pre-hyperfiltration. The hyperfiltration group had higher hemoglobin A1c, higher urine albumin-to-creatinine ratio, increased glomerular basement membrane width and lower podocyte density compared to the pre-hyperfiltration group. A glomerular 1240-gene transcriptional signature identified in the hyperfiltration group was enriched for endothelial stress response signaling genes, including endothelin-1, tec-kinase and transforming growth factor-β1 pathways, with the majority of the transcripts mapped to endothelial and inflammatory cell clusters in kidney single cell transcriptional data. Thus, our analysis reveals molecular pathomechanisms associated with hyperfiltration in early diabetic kidney disease involving putative ligand-receptor pairs with downstream intracellular targets linked to cellular crosstalk between endothelial and mesangial cells.

To determine the relationship between renal hemodynamic function and neuropathy in adults with ≥50-years of type 1 diabetes (T1D) compared to nondiabetic controls.Glomerular filtration rate (GFR, inulin), effective renal plasma flow (ERPF, p-aminohippurate), modified Toronto Clinical Neuropathy Score (mTCNS), corneal confocal microscopy, nerve conduction, and heart rate variability (autonomic function) were measured; afferent (RHigher mTCNS associated with lower renal blood flow (β ± SE:-9.29 ± 4.20, p = 0.03) and greater RAlthough neurological dysfunction in the presence of diabetes may contribute to impaired renal blood flow resulting in ischemic injury in patients with T1D, early autonomic dysfunction does not appear to be associated with kidney function changes.

Kidney failure is an important outcome for patients, clinicians, researchers, healthcare systems, payers, and regulators. However, no harmonized international consensus definitions of kidney failure and key surrogates of progression to kidney failure exist specifically for clinical trials. The International Society of Nephrology convened an international multi-stakeholder meeting to develop consensus on this topic. A core group, experienced in design, conduct, and outcome adjudication of clinical trials, developed a database of 64 randomized trials and the 163 included definitions relevant to kidney failure. Using an iterative process, a set of proposed consensus definitions were developed and subsequently vetted by the larger multi-stakeholder group of 83 participants representing 18 different countries. The consensus of the meeting participants was that clinical trial kidney failure outcomes should be comprised of a composite that includes receipt of a kidney transplant, initiation of maintenance dialysis, and death from kidney failure; it may also include outcomes based solely on laboratory measurements of glomerular filtration rate: a sustained low glomerular filtration rate and a sustained percent decline in glomerular filtration rate. Discussion included important considerations, such as (i) recognition of existing nomenclature for kidney failure; (ii) applicability across resource settings; (iii) ease of understanding for all stakeholders; and (iv) avoidance of inappropriate complexity so that the definitions can be used across ranges of populations and trial methodologies. The final definitions reflect the consensus for use in clinical trials.

We compared plasma metabolites of amino acid oxidation and the tricarboxylic acid (TCA) cycle in youth with and without type 1 diabetes mellitus (T1DM) and related the metabolites to glomerular filtration rate (GFR), renal plasma flow (RPF), and albuminuria. Metabolites associated with impaired kidney function may warrant future study as potential biomarkers or even future interventions to improve kidney bioenergetics.Metabolomic profiling of fasting plasma samples using a targeted panel of 644 metabolites and an untargeted panel of 19,777 metabolites was performed in 50 youth with T1DM ≤ 10 years and 20 controls. GFR and RPF were ascertained by iohexol and p-aminohippurate clearance, and albuminuria calculated as urine albumin to creatinine ratio. Sparse partial least squares discriminant analysis and moderated t tests were used to identify metabolites associated with GFR and RPF.Adolescents with and without T1DM were similar in age (16.1 ± 3.0 vs. 16.1 ± 2.9 years) and BMI (23.4 ± 5.1 vs. 22.7 ± 3.7 kg/mIn conclusion, adolescents with relatively short T1DM duration exhibited lower plasma levels of carboxylic acids that associated with hyperfiltration and hyperperfusion.ClinicalTrials.gov NCT03618420 and NCT03584217 A higher resolution version of the Graphical abstract is available as Supplementary information.

Coffee is one of the most frequently consumed beverages worldwide and has been found to have a wide assortment of health benefits. Although habitual coffee consumption is associated with a lower incidence of chronic kidney disease, an association between coffee and acute kidney injury (AKI) has not yet been revealed.In the Atherosclerosis Risk in Communities (ARIC) Study, a prospective cohort study of 14,207 adults aged 45 to 64 years, coffee consumption (cups/d) was assessed at a single visit via food frequency questionnaires and compared with incident AKI defined by hospitalization with an AKI-related International Classification of Diseases code.In ARIC, there were 1694 cases of incident AKI in a median of 24 follow-up years. Higher coffee consumption was associated with lower AKI risk versus no consumption (hazard ratio [HR] 1 cup/d: 0.92 [95% CI: 0.79-1.08]; 1 cup/d: 1.08 [95% CI: 0.94-1.24]; 2 to 3 cups/d: 0.83 [95% CI: 0.72-0.95];3 cups/d: 0.83 [95% CI: 0.71-0.96]; reference: never,Higher coffee intake was associated with a lower risk of incident AKI and could present an opportunity for cardiorenal protection through diet. Further evaluation of the physiological mechanisms underlying the cardiorenal protective effects of coffee consumption is necessary.