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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.

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.

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.

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.

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.

Diabetic kidney disease (DKD) is a common complication of type 1 diabetes (T1D) and a major risk factor for premature death from cardiovascular disease (CVD). Current treatments, such as control of hyperglycaemia and hypertension, are beneficial, but only partially protect against DKD. Finding new, safe and effective therapies to halt nephropathy progression has proven to be challenging. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have demonstrated, in addition to glycaemic lowering, impressive protection against DKD and CVD progression in people with type 2 diabetes. Although these beneficial cardiorenal effects may also apply to people with T1D, supporting data are lacking. Furthermore, the increased rates of euglycaemic diabetic ketoacidosis may limit the use of this class in people with T1D. In this review we highlight the pathophysiology of DKD in T1D and the unmet need that exists. We further detail the beneficial and adverse effects of SGLT2 inhibitors based on their mechanism of action. Finally, we balance the effects in people with T1D and indicate future lines of research.

Contains fulltext : 218649pub.pdf (Publisher’s version ) (Closed access) Contains fulltext : 218649pos.pdf (Author’s version postprint ) (Open Access) Asymptomatic hyperuricaemia affects ~20% of the general population in the USA, with variable rates in other countries. Historically, asymptomatic hyperuricaemia was considered a benign laboratory finding with little clinical importance in the absence of gout or kidney stones. Yet, increasing evidence suggests that asymptomatic hyperuricaemia can predict the development of hypertension, obesity, diabetes mellitus and chronic kidney disease and might contribute to disease by stimulating inflammation. Although urate has been classically viewed as an antioxidant with beneficial effects, new data suggest that both crystalline and soluble urate activate various pro-inflammatory pathways. This Review summarizes what is known about the role of urate in the inflammatory response. Further research is needed to define the role of asymptomatic hyperuricaemia in these pro-inflammatory pathways.

OBJECTIVE To compare diabetic kidney disease (DKD) rates over 5 years of follow-up in two cohorts of severely obese adolescents with type 2 diabetes (T2D) undergoing medical or surgical treatment for T2D. RESEARCH DESIGN AND METHODS A secondary analysis was performed of data collected from obese participants of similar age and racial distribution enrolled in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) and the Treatment Options of Type 2 Diabetes in Adolescents and Youth (TODAY) studies. Teen-LABS participants underwent metabolic bariatric surgery (MBS). TODAY participants were randomized to metformin alone or in combination with rosiglitazone or intensive lifestyle intervention, with insulin therapy given for glycemic progression. Glycemic control, BMI, estimated glomerular filtration rate (eGFR), urinary albumin excretion (UAE), and prevalence of hyperfiltration (eGFR ≥135 mL/min/1.73 m2) and elevated UAE (≥30 mg/g) were assessed annually. RESULTS Participants with T2D from Teen-LABS (n = 30, mean ± SD age, 16.9 ± 1.3 years; 70% female; 60% white; BMI 54.4 ± 9.5 kg/m2) and TODAY (n = 63, age 15.3 ± 1.3 years; 56% female; 71% white; BMI 40.5 ± 4.9 kg/m2) were compared. During 5 years of follow-up, hyperfiltration decreased from 21% to 18% in Teen-LABS and increased from 7% to 48% in TODAY. Elevated UAE decreased from 27% to 5% in Teen-LABS and increased from 21% to 43% in TODAY. Adjusting for baseline age, sex, BMI, and HbA1c, TODAY participants had a greater odds of hyperfiltration (odds ratio 15.7 [95% CI 2.6, 94.3]) and elevated UAE (27.3 [4.9, 149.9]) at 5 years of follow-up. CONCLUSIONS Compared with MBS, medical treatment of obese youth with T2D was associated with a higher odds of DKD over 5 years.

Fructose is distinct among common sugars in its ability to raise serum uric acid, and some studies suggest fructose-induced uric acid production may have a role in the ability of this sugar to induce metabolic syndrome. A fructose tolerance test has been previously developed to evaluate the relative ability of fructose to raise uric acid in individuals. However, the effect of fructose to raise uric acid in people with diabetes has not been studied.People with type 2 diabetes (n = 143) and without diabetes controls (n = 132) with similar body mass index (BMI) underwent an oral fructose tolerance test. As a comparison, participants also had their uric acid levels measured after an oral glucose tolerance test on a different day.Serum uric acid was lower in people with type 2 diabetes compared to controls with a similar BMI, especially those with poor glucose control (glycosylated hemoglobin [HbA1c] ≥ 8%). Fructose administration raised serum uric acid in both groups, with a lower absolute rise in people with diabetes. People with diabetes with a blunted rise in serum uric acid had higher baseline serum uric acid concentrations and a higher BMI. People without diabetes with a higher BMI also showed a blunted serum uric acid response. Oral glucose administration lowered serum uric acid in both participants, with a greater fall in those with diabetes.Both the presence of diabetes and obesity blunt the serum uric acid response to fructose ingestion. These data demonstrate altered fructose-dependent urate metabolism in type 2 diabetes.背景: 果糖与一般的糖不同之处在于它可以升高血清尿酸含量。一些研究表明, 果糖所产生的尿酸可能会在诱导代谢综合征中发挥作用。目前, 果糖耐量试验已用于评估个体中果糖对尿酸的提高相对量。然而, 对于糖尿病患者, 还未研究过果糖升高尿酸的影响。 方法: 研究者对体重指数(BMI)相近的2型糖尿病患者(n=143)和非糖尿病对照组(n=132)进行口服果糖耐量试验。作为比较, 受试者还在另一天行口服葡萄糖耐量试验, 测量其尿酸水平。 结果: 与体重指数相近的对照组相比, 2型糖尿病患者的基础血尿酸水平较低, 特别是那些血糖控制较差的人(糖化血红蛋白[HbA1c]≥8%)。服用果糖提升了两组的血尿酸水平, 糖尿病患者的绝对升幅较低。血清尿酸升高缓慢的糖尿病患者有较高的基线血尿酸浓度和较高的BMI。没有糖尿病、BMI较高的人也表现出血清尿酸反应迟钝。口服葡萄糖降低了两组受试者的血尿酸, 其中糖尿病患者的下降幅度更大。 结论: 糖尿病和肥胖的存在, 都会削弱血清尿酸对于果糖摄入的反应。这些数据表明糖尿病患者对于果糖依赖性的尿酸代谢显示异常.

OBJECTIVE We sought to evaluate copeptin concentrations in adolescents with and without type 1 diabetes (T1D) and examine the associations between copeptin and measures of arterial stiffness and kidney dysfunction. RESEARCH DESIGN AND METHODS This analysis included 169 adolescents with T1D (12-19 years of age, 59% girls, mean HbA1c 9.0 ± 1.5% and diabetes duration of 8.6 ± 2.9 years), in addition to 61 controls without T1D. Arterial stiffness including carotid-femoral pulse wave velocity (CF-PWV), carotid-radial PWV (CR-PWV), augmentation index normalized to heart rate of 75 bpm (AIx@HR75), and brachial artery distensibility (BAD). Serum copeptin, urinary albumin-to-creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) by serum creatinine and cystatin C were also assessed. RESULTS Compared to controls, adolescents with T1D had higher median (Q1-Q3) copeptin (7.5 [5.2-11.3] vs 6.4 [4.8-8.3] pmol/L, P = .01), mean ± SD eGFR (121 ± 23 vs 112 ± 16 mL/min/1.73m2 , P = .002) and lower BAD (7.1 ± 1.3 vs 7.2 ± 1.2%, P = .02). Adolescents with T1D in the in high tertile copeptin group (>9.1 pmol/L) had higher AIx@HR75 (10.7 ± 1.2 vs 5 ± 1.2, P = .001), CR-PWV (5.30 ± 1.0 vs 5.18 ± 1.0 m/s, P = .04), and UACR (12 ± 1 vs 8 ± 1 mg/g, P = .025) compared to those in low tertile (

Background and objectives Marathon runners develop transient AKI with urine sediments and injury biomarkers suggesting nephron damage. Design, setting, participants, & measurements To investigate the etiology, we examined volume and thermoregulatory responses as possible mechanisms in runners’ AKI using a prospective cohort of runners in the 2017 Hartford Marathon. Vitals, blood, and urine samples were collected in 23 runners 1 day premarathon and immediately and 1 day postmarathon. We measured copeptin at each time point. Continuous core body temperature, sweat sodium, and volume were assessed during the race. The primary outcome of interest was AKI, defined by AKIN criteria. Results Runners ranged from 22 to 63 years old; 43% were men. Runners lost a median (range) of 2.34 (0.50–7.21) g of sodium and 2.47 (0.36–6.81) L of volume via sweat. After accounting for intake, they had a net negative sodium and volume balance at the end of the race. The majority of runners had increases in core body temperature to 38.4 (35.8–41)°C during the race from their baseline. Fifty-five percent of runners developed AKI, yet 74% had positive urine microscopy for acute tubular injury. Runners with more running experience and increased participation in prior marathons developed a rise in creatinine as compared with those with lesser experience. Sweat sodium losses were higher in runners with AKI versus non-AKI (median, 3.41 [interquartile range (IQR), 1.7–4.8] versus median, 1.4 [IQR, 0.97–2.8] g; P=0.06, respectively). Sweat volume losses were higher in runners with AKI versus non-AKI (median, 3.89 [IQR, 1.49–5.09] versus median, 1.66 [IQR, 0.72–2.84] L; P=0.03, respectively). Copeptin was significantly higher in runners with AKI versus those without (median, 79.9 [IQR, 25.2–104.4] versus median, 11.3 [IQR, 6.6–43.7]; P=0.02, respectively). Estimated temperature was not significantly different. Conclusions All runners experienced a substantial rise in copeptin and body temperature along with salt and water loss due to sweating. Sodium and volume loss via sweat as well as plasma copeptin concentrations were associated with AKI in runners. Podcast This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2019_08_13_CJASNPodcast_19_09_.mp3

Introduction: Glomerular filtration rate (GFR) is routinely used for clinical assessment of kidney function. However, the accuracy of estimating equations in older adults is uncertain. Methods: In 66 adults with ≥50 years type 1 diabetes (T1D) duration and 73 nondiabetic controls from age/sex-matched subgroups (65 ± 8 years old and 77[55%] were women) we evaluated the performance of estimated GFR (eGFR) by creatinine (Modification of Diet and Renal Disease [MDRD], Chronic Kidney Disease–Epidemiology [CKD-EPI]cr), cystatin C (CKD-EPIcys, CKD-EPIcr-cys), and β2-microglobulin (β2M) compared with measured GFR by inulin clearance (mGFR). Performance was evaluated using metrics of bias (mean difference), precision (SD), and accuracy (proportion of eGFR that differed by >20% of mGFR). Results: Mean mGFR was 104 ± 18 ml/min per 1.73 m2 (range: 70–154 ml/min per 1.73 m2) and was not different between T1D and controls (103 ± 17 vs. 105 ± 19 ml/min per 1.73 m2, P = 0.39). All equations significantly underestimated mGFR (bias: −15 to −30 ml/min per 1.73 m2, P < 0.001 for all comparisons) except for β2M, which had bias of 1.9 ml/min per 1.73 m2 (P = 0.61). Bias was greatest in cystatin C–based equations. Precision was lowest for β2M (SD: 43.5 ml/min per 1.73 m2, P < 0.001 for each comparison). Accuracy was lowest for CKD-EPIcysC (69.1%, P < 0.001 for each comparison). Cystatin C–based equations demonstrated greater bias and lower accuracy in older age subgroups (

OBJECTIVE Elevated serum uric acid (SUA) is increasingly recognized as a risk factor for kidney disease in adults with diabetes, but data in youth are limited. We hypothesized that elevated SUA predicts development of elevated urinary albumin excretion (UAE) and hypertension over time in teens with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Serum creatinine, cystatin C, SUA, and the urine albumin-to-creatinine ratio (UACR) were assessed in 539 obese youth, ages 12–17 years, with T2D duration RESULTS At baseline, hyperuricemia (≥6.8 mg/dL) was present in 25.6% of participants, hypertension in 18.7%, and elevated UAE in 6.1%. During follow-up of up to 7 years, hypertension developed in 37.4% and UAE in 18.0%. Higher baseline SUA increased the risk of incident hypertension (hazard ratio [HR] 1.19, 95% CI 1.03–1.38, per 1 mg/dL increase in SUA) and elevated UAE (HR 1.24, 95% CI 1.03–1.48) in adjusted models. CONCLUSIONS Hyperuricemia was common in youth with T2D. Higher baseline SUA independently increased the risk for onset of hypertension and elevated UAE. Research is needed to determine whether SUA-lowering therapies can impede development of diabetic kidney disease and hypertension in T2D youth.

Sodium glucose cotransporter (SGLT)-2 inhibitors are the newest addition to our treatment armamentarium for the management of hyperglycemia in type 2 diabetes. Glucose-lowering per se reduces the risk of microvascular complications, but not the risk of cardiovascular disease, including heart failure and cardiovascular mortality. Also, even when embedded in optimal cardiovascular prevention, a large residual risk remains with respect to progression of diabetic kidney disease. SGLT-2 inhibitors lower blood glucose levels by inducing glucosuria. Through various proposed mechanisms, among which diuretic and natriuretic effects, SGLT-2 inhibitors decrease heart failure hospitalization, reduce cardiovascular mortality, and mitigate progression of diabetic kidney disease. In this perspective, we will discuss the glucose-lowering and other protective effects of SGLT-2 inhibitors on the cardiorenal axis, both in primary and secondary prevention. By comparing the glycemic and pleiotropic effects of these agents to other glucose-lowering drugs, we will address questions around whether SGLT-2 inhibitors should be considered primarily as glucose-lowering agents, cardiorenal drugs or both.

AIMS To examine the relationship between normal plasma uric acid (PUA) levels, renal haemodynamic function, arterial stiffness and plasma renin and aldosterone over a wide range of type 1 diabetes (T1D) durations in adolescents, young adults and older adults. MATERIALS AND METHODS PUA, glomerular filtration rate (GFR), effective renal plasma flow (ERPF), vascular stiffness parameters (aortic augmentation index [AIx], carotid AIx, carotid femoral pulse wave velocity [cfPWV]), and plasma renin and aldosterone were measured during a euglycaemic clamp in people with T1D: 27 adolescents (mean ± SD age 16.8 ± 1.9 years), 52 young adults (mean ± SD age 25.6 ± 5.5 years) and 66 older adults (mean ± SD age 65.7 ± 7.5 years). RESULTS PUA was highest in patients with the longest T1D duration: 197 ± 44 μmol/L in adolescents versus 264 ± 82 μmol/L in older adults (P

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.).

No longitudinal data link intraglomerular hemodynamic dysfunction with end-stage kidney disease (ESKD) in people with type 2 diabetes (T2D). Afferent (RA) and efferent (RE) arteriolar tone and intraglomerular pressure (PGLO) are not directly measurable in humans but are estimable from glomerular filtration rate (GFR), renal plasma flow (RPF), blood pressure, hematocrit, and plasma oncotic pressure. We examined the association of the RA/RE ratio and PGLO with ESKD incidence in 237 Pima Indian persons with T2D who underwent serial measures of GFR (iothalamate) and RPF (p-aminohippurate). Their association with kidney structural lesions was also examined in a subset of 111 participants. Of the 237 participants (mean age 42 years, diabetes duration 11 years, GFR 153 ml/min, median ACR 36 mg/g), 69 progressed to ESKD during median follow-up of 17.5 years. In latent class analysis, distinct trajectories characterized by increasing RA/RE ratio (HR: 4.60, 95% CI 2.55-8.31) or elevated PGLO followed by a rapid decline (HR: 2.96, 95% CI 1.45-6.02) strongly predicted incident ESKD. PGLO (R2=21%, pA/RE (R2=15%, p In conclusion, intraglomerular hemodynamic parameters associated strongly with incident ESKD and correlated with structural lesions of DKD.

Diabetic kidney disease (DKD) is the leading cause of end stage kidney disease (ESKD). Higher rates of death and ESKD are seen in YO vs. AO T2D; however, no studies have evaluated differences in structural lesions from kidney biopsies in YO and AO T2D. 161 Pima Indians with T2D underwent kidney biopsies. Quantitative morphometry was performed and participants were stratified as YO ( Disclosure H. C. Looker: None. C. Severn: None. T. B. Vigers: None. L. Pyle: None. P. Saulnier: None. B. Najafian: Consultant; Self; 4DMT, Sangamo Therapeutics, Sanofi Genzyme, Research Support; Self; Amicus. M. Mauer: Consultant; Self; Freeline Therapeutics, Research Support; Self; Amicus, Sanofi Genzyme. R. G. Nelson: None. P. Bjornstad: Advisory Panel; Self; XORTX Therapeutics Inc., Consultant; Self; AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb Company, Lilly Diabetes, Novo Nordisk, Research Support; Self; Horizon Therapeutics plc. Funding American Diabetes Association (1-08-CR-42 to R.G.N.); National Institute of Diabetes and Digestive and Kidney Diseases (DK116720, DK114886); JDRF (2-SRA-2019-845-S-B); Boettcher Foundation

Diabetic kidney disease remains the leading cause of end‐stage kidney disease and a major risk factor for cardiovascular disease. Large cardiovascular outcome trials and dedicated kidney trials have shown that sodium‐glucose cotransporter (SGLT)2 inhibitors reduce cardiovascular morbidity and mortality and attenuate hard renal outcomes in patients with type 2 diabetes (T2D). Underlying mechanisms explaining these renal benefits may be mediated by decreased glomerular hypertension, possibly by vasodilation of the post‐glomerular arteriole. People with T2D often receive several different drugs, some of which could also impact the renal vasculature, and could therefore modify both renal efficacy and safety of SGLT2 inhibition. The most commonly prescribed drugs that could interact with SGLT2 inhibitors on renal haemodynamic function include renin‐angiotensin system inhibitors, calcium channel blockers and diuretics. Herein, we review the effects of these drugs on renal haemodynamic function in people with T2D and focus on studies that measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) with gold‐standard techniques. In addition, we posit, based on these observations, potential interactions with SGLT2 inhibitors with an emphasis on efficacy and safety., SUMMARY AT A GLANCE This invited review describes the renal haemodynamic and protective effects of commonly prescribed drugs in people with type 2 diabetes and their interaction with SGLT2 inhibitors.

Diabetic kidney disease (DKD) is a common complication of type 1 and 2 diabetes and often presents during adolescence and young adulthood. Given the growing incidence of both type 1 and type 2 diabetes in children and adolescents, DKD represents a significant public health problem. Acute kidney injury (AKI) in youth with diabetes is strongly associated with risk of DKD development. This review will summarize the epidemiology and pathophysiology of AKI in children with diabetes, the relationship between AKI and DKD, and the potential therapeutic interventions. Finally, we will appraise the impact of the recent COVID-19 infection pandemic on AKI in children with diabetes.

Sexual dimorphism may play a key role in the pathogenesis of diabetic kidney disease (DKD) and explain differences observed in disease phenotypes, responses to interventions, and disease progression between men and women with diabetes. Therefore, omitting the consideration of sex as a biological factor may result in delayed diagnoses and suboptimal therapies. This review will summarize the effects of sexual dimorphism on putative metabolic and molecular mechanisms underlying DKD, and the potential implications of these differences on therapeutic interventions. To successfully implement precision medicine, we require a better understanding of sexual dimorphism in the pathophysiologic progression of DKD. Such insights can unveil sex-specific therapeutic targets that have the potential to maximize efficacy while minimizing adverse events.

Objective Arginine vasopressin (AVP) and its surrogate, copeptin, have been implicated in diabetic kidney disease (DKD) pathogenesis, which develops in a subset of people with longstanding type 1 diabetes, but not in others (DKD Resistors). We hypothesized that patients with DKD would exhibit higher copeptin concentrations vs. DKD Resistors. Methods Participants with type 1 diabetes (n = 62, duration ≥50 years) were stratified into 42 DKD Resistors and 20 with DKD (eGFR ≤60 mL/min/1.73m2 or ≥30 mg/day urine albumin), and age/sex-matched controls (HC, n = 74) were included. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were calculated by inulin and p-aminohippurate clearance before and after angiotensin II (ang II) infusion. Renal vascular resistance (RVR) was calculated as mean arterial pressure/renal blood flow. Plasma copeptin, renin, aldosterone, neutrophil gelatinase-associated lipocalin (NGAL), and urea concentrations were measured, along with 24-h urine volume. Results DKD resistors had lower copeptin (95% CI: 4.0 [3.4–4.8] pmol/l) compared to DKD (5.8 [4.5–7.6] pmol/l, p = 0.02) and HC (4.8 [4.1–5.5] pmol/l, p = 0.01) adjusting for age, sex and HbA1c. In type 1 diabetes, higher copeptin correlated with lower GFR (r: −0.32, p = 0.01) and higher renin concentration (r: 0.40, p = 0.002) after multivariable adjustments. These relationships were not evident in HC. Copeptin inversely associated with RVR change following exogenous ang II only in participants with type 1 diabetes (β ± SE: −6.9 ± 3.4, p = 0.04). Conclusions In longstanding type 1 diabetes, copeptin was associated with intrarenal renin–angiotensin–aldosterone system (RAAS) activation and renal hemodynamic function, suggesting interplay between AVP and RAAS in DKD pathogenesis.

The renin angiotensin aldosterone system (RAAS) is associated with renal disease and inflammation in a diabetes setting, however, little is known about the implicated mechanisms in individuals with long standing diabetes. Accordingly, our aim was to perform an observational study to quantify urinary excretion of inflammatory biomarkers in participants with long standing type 1 diabetes (T1D) (with and without diabetic kidney disease [DKD]) and controls, at baseline and in response to RAAS activation. GFRINULIN, ERPFPAH, and 42 urine inflammatory biomarkers were measured in 74 participants with T1D for ≥50 years (21 with DKD and 44 without DKD [DKD resistors]) and 73 healthy controls. Additionally, inflammatory biomarkers were measured before and after an angiotensin II infusion (ANGII, 1 ng∙kg−1∙min−1). Significantly lower urinary excretion of cytokines (IL-18, IL-1RA, IL-8), chemokines (MCP1, RANTES) and growth factors (TGF-α, PDGFAA, PDGFBB, VEGF-A) was observed in participants with T1D at baseline compared to controls. Urinary IL-6 was higher in DKD than in DKD resistors in an exploratory analysis unadjusted for multiple comparisons. In T1D only, lower GFRINULIN correlated with greater excretion of proinflammatory biomarkers (IL-18, IP-10, & RANTES), growth factors (PDGF-AA & VEGFAA), and chemokines (eotaxin & MCP-1). ANGII increased 31 of 42 inflammatory biomarkers in T1D vs controls (p

Background Cardiovascular disease (CVD) remains the leading cause of mortality in type 2 diabetes (T2D). Better interventions are needed to mitigate the high lifetime risk for CVD in youth T2D. Objective To compare 30-year risk for CVD events in 2 cohorts of adolescents with T2D and severe obesity undergoing medical or surgical treatment of T2D. Setting Longitudinal multicenter studies at University hospitals. Methods A secondary analysis of data collected from the participants with T2D enrolled in the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS, n = 30) and participants of similar age and racial distribution from the Treatment Options of Type 2 Diabetes in Adolescents and Youth (TODAY, n = 63) studies was performed. Teen-LABS participants underwent metabolic bariatric surgery (MBS). TODAY participants were randomized to metformin alone or in combination with rosiglitazone or intensive lifestyle intervention, with insulin therapy given for glycemic progression. A 30-year CVD event score developed by the Framingham Heart Study was the primary outcome, assessed at baseline (preoperatively for Teen-LABS), 1 year, and 5 years of follow-up. Results Participants with T2D from Teen-LABS (n = 30; mean ± SD age = 16.9 ± 1.3 yr; 70% female; 60% white; body mass index (BMI) = 54.4 ± 9.5 kg/m2) and TODAY (n = 63; 15.3 ± 1.3 yr; 56% female; 71% white; BMI 40.5 ± 4.9 kg/m2) were compared. The likelihood of CVD events was higher in Teen-LABS versus TODAY at baseline (17.66 [1.59] versus 12.11 [.79]%, adjusted P = .002). One year after MBS, event risk was significantly lower in Teen-LABS versus TODAY (6.79 [1.33] versus 13.64 [0.96]%, adjusted P Conclusion Despite higher pretreatment risk for CVD events, treatment with MBS resulted in a reduction in estimated CVD event risks, whereas medical therapy associated with an increase in risk among adolescents with T2D and severe obesity.

The relationship between renal function and neuropathy is not well established in T1D. Our objective was to determine the relationship between renal hemodynamic function and neuropathy in adults with a ≥50-year history of T1D compared to nondiabetic controls. GFR (inulin), effective renal plasma flow (ERPF, p-aminohippurate) and modified Toronto Clinical Neuropathy Score (mTCNS) were measured in 66 patients with T1D for ≥50-years and in 73 patients without diabetes matched for age and sex. Afferent (RA), efferent (RE) arteriolar resistances and glomerular hydrostatic pressure (PGLO) were estimated using Gomez’s equations. Presence of DKD was defined as eGFRMDRD30mg/day at the screening visit. Linear regressions were applied to examine the relationships between renal function (dependent variable) and measures of neuropathy (independent variable), adjusted for age, sex and HbA1c in participants with T1D and for age and sex in nondiabetic controls. Greater mTCNS, a measure of neuropathy signs and symptoms, was associated with lower renal blood flow (β=-9.57±4.15, p=0.024) and greater RE (β=32.79±15.13, p=0.034) in adults with T1D after adjusting for age, sex and HbA1c. Participants with T1D and DKD had a greater mTCNS compared to those without DKD (6.3±5.2 vs. 3.8±3.6, p=0.016). In contrast, renal hemodynamic parameters did not associate with measures of neuropathy in nondiabetic controls in multivariable models. Neuropathy score was associated with lower renal perfusion in adults with longstanding T1D. Neurological dysfunction in the presence of diabetes may contribute to impaired renal perfusion resulting in ischemic injury in patients with T1D. Further work is required to understand factors - including the autonomic nervous system - that contribute to maintaining normal renal perfusion in longstanding T1D. Disclosure Y. Lytvyn: None. P. Bjornstad: Advisory Panel; Self; XORTX Therapeutics Inc. Consultant; Self; Bayer AG, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb, Novo Nordisk Foundation. Research Support; Self; Horizon Pharma. L. Lovblom: None. H. Liu: None. J.A. Lovshin: Consultant; Self; AstraZeneca. Consultant; Spouse/Partner; Bayer Inc. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Novo Nordisk Inc. Research Support; Self; Novo Nordisk Inc. G. Boulet: Advisory Panel; Self; Medtronic. M. Farooqi: None. A. Weisman: None. H.A. Keenan: None. M.H. Brent: Advisory Panel; Self; Bayer AG, Novartis Pharmaceuticals Canada Inc., Roche Canada. N. Paul: None. V. Bril: Advisory Panel; Self; Alexion Pharmaceuticals, Inc., Alnylam Pharmaceuticals, Takeda Canada. Consultant; Self; Akcea Therapeutics, CSL Behring, Sanofi. Research Support; Self; Biogen, Grifols, Momenta Pharmaceuticals. B.A. Perkins: Consultant; Self; Abbott, Boehringer Ingelheim International GmbH, Insulet Corporation. Research Support; Self; Boehringer Ingelheim International GmbH, Novo Nordisk A/S. Other Relationship; Self; Medtronic. D. Cherney: Research Support; Self; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca and Novo-Nordisk. Other Relationship; Self; from Boehringer Ingelheim-Lilly, Merck, AstraZeneca, Sanofi, Mitsubishi-Tanabe, Abbvie, Janssen, Bayer, Prometic, BMS and Novo-Nordisk.

The balance of RA and RE, a major determinant of intraglomerular pressure (P Disclosure P. Saulnier: None. H.C. Looker: None. M. Mauer: None. R.G. Nelson: None. P. Bjornstad: Advisory Panel; Self; XORTX Therapeutics Inc. Consultant; Self; Bayer AG, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb, Novo Nordisk Foundation. Research Support; Self; Horizon Pharma. Funding American Diabetes Association (1-08-CR-42 to R.G.N.); National Institute of Diabetes and Digestive and Kidney Diseases

Glomerular filtration rate (GFR) is a major determinant of renal energy expenditure. Animal models support a mismatch between renal oxygenation (RO2) and energy expenditure in diabetic kidney disease (DKD). The objective of this study was to compare the ratio of RO2 to GFR (RO2:GFR) in adolescents with and without type 1 diabetes (T1D) and correlate the ratio with albuminuria, effective renal plasma flow (ERPF), blood pressure, trunk mass and renal oxygen consumption. RO2 was measured by blood oxygenation level dependent (BOLD) MRI before and after 20 mg of I.V. furosemide, trunk mass by DXA, GFR by iohexol clearance, ERPF by p-aminohippurate clearance and albuminuria by urine albumin-to-creatinine ratio (UACR) in 50 adolescents with T1D (mean age 16.1±3.0 yrs, trunk mass 44.8±2.2%, HbA1c 8.6±1.2%, GFR 189±40 ml/min) and 20 non-obese controls (mean age 16.1±2.9 yrs, trunk mass 44.9±2.2%, HbA1c 5.2±0.2%, GFR 136±22 ml/min). The RO2:GFR (s/ml/min*1000) was calculated as renal oxygenation (T2*, s) divided by GFR (ml/min), and furosemide-suppressible oxygenation (FSOC) as change in RO2 in responses to furosemide. Relationships were evaluated by correlation and multivariable generalized linear regression models. RO2:GFR was 25% lower in adolescents with T1D vs. controls (mean±SD: 0.24±0.04 vs. 0.32±0.04, p Disclosure C.L. Vinovskis: None. K.J. Nadeau: None. K.L. Tommerdahl: None. P.V. Prasad: None. L. Li: None. L. Pyle: None. M. Rewers: None. M. Pragnell: None. F.H. Mahmud: Advisory Panel; Self; Eli Lilly and Company, Insulet Corporation. D.H. van Raalte: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Merck & Co., Inc., Sanofi. Research Support; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Merck & Co., Inc., Sanofi. D. Cherney: Research Support; Self; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca and Novo-Nordisk. Other Relationship; Self; from Boehringer Ingelheim-Lilly, Merck, AstraZeneca, Sanofi, Mitsubishi-Tanabe, Abbvie, Janssen, Bayer, Prometic, BMS and Novo-Nordisk. R. Nelson: None. P. Bjornstad: Advisory Panel; Self; XORTX Therapeutics Inc. Consultant; Self; Bayer AG, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb, Novo Nordisk Foundation. Research Support; Self; Horizon Pharma. Funding JDRF (2-SRA-2018-627-M-B); National Institute of Diabetes and Digestive and Kidney Diseases (K23DK116720)

OBJECTIVE Following metabolic and bariatric surgery (MBS), most adolescents experience weight loss and improvement of many obesity-associated complications (OACs). The relationship between weight loss and remission of OACs after MBS in adolescents has not been well described. METHODS The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) is a multi-institutional prospective observational study of adolescents who underwent MBS between 2007 and 2012. Lower-weight-loss responders (LWLRs) were defined as having

Objectives: Diabetic kidney disease (DKD) is an independent predictor of cardiovascular morbidity and mortality in type 1 diabetes (T1D). We aimed to explore clinical and biochemical factors, including the achievement of American Diabetes Association (ADA) recommended targets associated with DKD in people living with T1D for ≥50 years. Methods: This was a post hoc analysis of a cross-sectional study of 75 participants enrolled in the Canadian Study of Longevity in T1D. We explored diabetes-related complications, including neuropathy, retinopathy, cardiovascular disease, and DKD. Study participants were dichotomized based on the achievement of ADA recommended targets as the low-target group (achieving ≤4 targets, n = 31) and high-target group (achieving >4 targets, n = 44). The outcome of interest was DKD defined by estimated glomerular filtration rate (eGFR) values 30 mg. Multivariable logistic regression models were employed to estimate odds ratios (ORs) for DKD with 95% confidence intervals (CIs). Results: Of the 75 participants with prolonged T1D duration (45% male, mean age 66 years), 25 participants had DKD and 50 did not. There was no statistical difference between the high- and low-target groups in terms of age and body mass index. eGFR was significantly higher and the prevalence of diabetic retinopathy was significantly lower in the high-target group. Older age at diagnosis of T1D and lower frequency component to high-frequency component ratio increased the odds of having DKD. Conclusions: In adults with prolonged T1D duration, older age at diagnosis and lower heart rate variability may be associated with DKD.

Bariatric surgery, an emerging treatment for severely obese youth with and without T2D, provides marked improvement in insulin resistance, beta-cell function, and central adiposity. Further, preliminary data suggest that bariatric surgery also results in significant improvement in markers of obesity-related nephropathy and DKD, beyond that which can be achieved with current medical interventions. Yet, the mechanisms whereby bariatric surgery attenuates kidney disease remain unclear. This review summarizes the data on the effects of bariatric surgery on obesity-related nephropathy and DKD in youth with and without T2D, in addition to potential mechanisms underlying the nephroprotective effects of weight loss surgery and how these may differ in Roux-en-Y gastric bypass vs. vertical sleeve gastrectomy. Finally, we discuss potential future non-surgical therapies to mitigate kidney disease.

Background: Cardiovascular disease is the leading cause of mortality in type 1 diabetes mellitus (T1DM) and relates strongly to insulin resistance (IR). Lean and obese adolescents with T1DM have marked IR. Metformin improves surrogate markers of IR in T1DM, but its effect on directly measured IR and vascular health in youth with T1DM is unclear. We hypothesized that adolescents with T1DM have impaired vascular function and that metformin improves this IR and vascular dysfunction. Methods: Adolescents with T1DM and control participants underwent magnetic resonance imaging of the ascending (AA) and descending aorta to assess pulse wave velocity, relative area change, and maximal (WSS MAX ) and time-averaged (WSS TA ) wall shear stress. Participants with T1DM also underwent assessment of carotid intima-media thickness by ultrasound, brachial distensibility by DynaPulse, fat and lean mass by dual-energy x-ray absorptiometry, fasting laboratories after overnight glycemic control, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (glucose infusion rate/insulin). Adolescents with T1DM were randomized 1:1 to 3 months of 2000 mg metformin or placebo daily, after which baseline measures were repeated. Results: Forty-eight adolescents with T1DM who were 12 to 21 years of age (40% body mass index [BMI] ≥90th percentile; 56% female) and 24 nondiabetic control participants of similar age, BMI, and sex distribution were enrolled. Adolescents with T1DM demonstrated impaired aortic health compared with control participants, including elevated AA and descending aorta pulse wave velocity, reduced AA and descending aorta relative area change, and elevated AA and descending aorta WSS MAX and WSS TA . Adolescents with T1DM in the metformin versus placebo group had improved glucose infusion rate/insulin (12.2±3.2 [mg·kg −1 ·min −1 ]/μIU/μL versus −2.4±3.6 [mg·kg −1 ·min −1 ]/μIU/μL, P =0.005; 18.6±4.8 [mg·lean kg −1 ·min −1 ]/μIU/μL versus −3.4±5.6 [mg·lean kg −1 ·min −1 ]/μIU/μL, P =0.005) and reduced weight (−0.5±0.5 kg versus 1.6±0.5 kg; P =0.004), BMI (−0.2±0.15 kg/m 2 versus 0.4±0.15 kg/m 2 ; P =0.005), and fat mass (−0.7±0.3 kg versus 0.6±0.4 kg; P =0.01). Glucose infusion rate/insulin also improved in normal-weight participants (11.8±4.4 [mg·kg −1 ·min −1 ]/μIU/μL versus −4.5±4.4 [mg·kg −1 ·min −1 ]/μIU/μL, P =0.02; 17.6±6.7 [mg·lean kg −1 ·min −1 ]/μIU/μL versus −7.0±6.7 [mg·lean kg −1 ·min −1 ]/μIU/μL, P =0.02). The metformin group had reduced AA WSS MAX (−0.3±0.4 dyne/cm 2 versus 1.5±0.5 dyne/cm 2 ; P =0.03), AA pulse wave velocity (−1.1±1.20 m/s versus 4.1±1.6 m/s; P =0.04), and far-wall diastolic carotid intima-media thickness (−0.04±0.01 mm versus −0.00±0.01 mm; P =0.049) versus placebo. Conclusions: Adolescents with T1DM demonstrate IR and impaired vascular health compared with control participants. Metformin improves IR, regardless of baseline BMI, and BMI, weight, fat mass, insulin dose, and aortic and carotid health in adolescents with T1DM. Metformin may hold promise as a cardioprotective intervention in T1DM. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01808690.

OBJECTIVE The importance of renin-angiotensin-aldosterone system (RAAS) activation in retinopathy for long-standing diabetes is not well understood. We determined retinopathy stage and evaluated associations with other vascular complications before and after physiological RAAS activation in adults with long-standing (≥50 years duration) type 1 diabetes. RESEARCH DESIGN AND METHODS Participants underwent retinal examination by digital funduscopic photography and optical coherence tomography and were classified as having nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), or no diabetic retinopathy (NDR) with or without diabetic macular edema (DME). Neuropathy was measured by clinical neuropathy examination scores, electrophysiologically, and by corneal confocal microscopy. Renal function was measured by inulin and para-aminohippurate clearance methods. Arterial stiffness was measured by applanation tonometry. Renal function, blood pressure, and arterial stiffness were measured before and after RAAS activation with angiotensin II (ANGII). Associations were determined using linear regression. RESULTS Twelve (16%) of the 75 participants had NDR, 24 (32%) had NPDR, and 39 (52%) had PDR. A low overall prevalence of DME (4%) was observed. Those with PDR had worse nerve function and reduced corneal nerve density, were more likely to have macrovascular disease, and had increased arterial stiffness in response to ANGII compared with those with NPDR or NDR. Prevalence of kidney disease or renal hemodynamic function did not differ by retinopathy status. CONCLUSIONS PDR was associated with neuropathy severity and cardiovascular and peripheral vascular disease. In those with PDR, RAAS activation may be linked to vascular stiffening, an effect that persists in long-standing type 1 diabetes.

OBJECTIVE Novel biomarkers are needed to better predict coronary artery calcification (CAC), a marker of subclinical atherosclerosis, and diabetic kidney disease (DKD) in type 1 diabetes. We evaluated the associations between serum uromodulin (SUMOD [a biomarker associated with anti-inflammatory and renal protective properties]), CAC progression, and DKD development over 12 years. RESEARCH DESIGN AND METHODS Participants (n = 527, 53% females) in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study were examined during 2002–2004, at a mean age of 39.6 ± 9.0 years and a median duration of diabetes of 24.8 years. Urine albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) determined by the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation were measured at baseline and after a mean follow-up period of 12.1 ± 1.5 years. Elevated albumin excretion was defined as ACR ≥30 mg/g, rapid GFR decline (>3 mL/min/1.73 m2/year), and impaired GFR as eGFR RESULTS Higher baseline SUMOD level conferred lower odds of CAC progression (odds ratio 0.68; 95% CI 0.48–0.97), incident elevated albumin excretion (0.37; 0.16–0.86), rapid GFR decline (0.56; 0.35–0.91), and impaired GFR (0.44; 0.24–0.83) per 1 SD increase in SUMOD (68.44 ng/mL) after adjustment for baseline age, sex, systolic blood pressure, LDL cholesterol, and albuminuria/GFR. The addition of SUMOD to models with traditional risk factors also significantly improved the prediction performance for CAC progression and incident DKD. CONCLUSIONS Higher baseline SUMOD level predicted lower odds of both CAC progression and incident DKD over 12 years in adults with type 1 diabetes.

OBJECTIVE Our aim was to define the relationships between plasma biomarkers of kidney injury and intrarenal haemodynamic function (glomerular filtration rate [GFR], effective renal plasma flow [ERPF], renal vascular resistance [RVR]) in adults with type 1 diabetes (T1D). METHODS The study sample comprised patients with longstanding T1D (duration ≥50 years), among whom 44 were diabetic kidney disease (DKD) resistors (eGFR >60 mL/min/1.73 m2 and

Summary Cardiovascular disease remains the leading cause of mortality in patients with type 1 diabetes. Although cardiovascular disease complications are rare until adulthood, pathology and early markers can manifest in adolescence. Whereas advances have been made in the management of microvascular complications of type 1 diabetes, similar progress in reducing macrovascular complications has not been made. The reasons for the absence of progress remain incompletely understood, but most likely relate to the long time needed for cardiovascular disease to manifest clinically and hence for risk factor management to show a clinical benefit, thus allowing inertia to prevail for diagnosis and particularly for targeting risk factors. In this Review, we summarise paediatric data on traditional and novel risk factors of cardiovascular disease, provide an overview of data from previous and current clinical trials, discuss future directions in cardiovascular disease research for paediatric patients with type 1 diabetes, and advocate for the early identification and treatment of cardiovascular disease risk factors as recommended in multiple guidelines.

Aims: To determine the effects of glucagon-like peptide (GLP)-1 receptor agonists (RA) on uric acid (UA) levels and kidney UA clearance. Material and methods: This study involved post-hoc analyses of 4 controlled clinical trials, which assessed actions of GLP-1RA administration on kidney physiology. The immediate effects of GLP-1RA exenatide infusion vs placebo were determined in 9 healthy overweight men (Study-A) and in 52 overweight T2DM patients (Study-B). The effects of 12 weeks of long-acting GLP-1RA liraglutide vs placebo in 36 overweight T2DM patients (Study-C) and of 8 weeks of short-acting GLP-1RA lixisenatide vs once-daily titrated insulin glulisine in 35 overweight T2DM patients (Study-D) were also examined. Plasma UA, fractional (inulin-corrected) and absolute urinary excretion of UA (UEUA) and sodium (UENa), and urine pH were determined. Results: Median baseline plasma UA level was 5.39 to 6.33 mg/dL across all studies (17%-22% of subjects were hyperuricaemic). In Study-A, exenatide infusion slightly increased plasma UA (+0.07 ± 0.02 mg/dL, P =.04), and raised absolute-UEUA (+1.58 ± 0.65 mg/min/1.73 m2, P =.02), but did not affect fractional UEUA compared to placebo. Fractional UEUA and absolute UEUA correlated with increases in urine pH (r:0.86, P =.003 and r:0.92, P

Adolescents with Type 1 diabetes mellitus (T1DM) are at risk for hyperfiltration and elevated urinary albumin-to-creatinine ratio (ACR), which are early indicators of diabetic nephropathy. Adolescents with T1DM also develop early changes in blood pressure, cardiovascular structure, and function. Our aims were to define the relationships between hyperfiltration, ACR, and 24-h ambulatory blood pressure over time in adolescents with T1DM. Normotensive, normoalbuminuric adolescents ( n = 98) with T1DM underwent baseline and 2-yr 24-h ambulatory blood pressure monitoring, glomerular filtration rate (eGFR) estimated by cystatin C (Larsson equation), and ACR measurements. Linear regression models adjusted for diabetes duration, sex, and HbA1c were used to determine associations. Hyperfiltration (eGFR ≥ 133 ml/min) was present in 31% at baseline and 21% at 2-yr follow-up. Hyperfiltration was associated with greater odds of rapid GFR decline (>3 ml·min−1·yr−1) [OR: 5.33, 95%; CI: 1.87–15.17; P = 0.002] over 2 yr. Natural log of ACR at baseline was associated with greater odds of hyperfiltration (OR: 1.71, 95% CI: 1.00–2.92; P = 0.049) and 2-yr follow-up (OR: 2.14, 95%; CI: 1.09–4.19; P = 0.03). One SD increase in eGFR, but not ln ACR, at 2-yr follow-up conferred greater odds of nighttime nondipping pattern (OR: 1.96, 95% CI: 1.06–3.63; P = 0.03). Hyperfiltration was prevalent at baseline and at 2-yr follow-up, predicted rapid decline in GFR, and was related to ACR. Elevated GFR at 2-yr follow-up was associated with nighttime nondipping pattern. More work is needed to better understand early relationships between renal hemodynamic and systemic hemodynamic changes in adolescents with T1DM to reduce future cardiorenal complications.

Uricosuria and crystallization are increasingly recognized risk factors for diabetic tubulopathy. This pilot clinical trial aimed to determine the acute effect of urinary alkalinization using oral sodium bicarbonate (NaHCO3 ) on UA crystals in adults with type 1 diabetes (T1D). Adults with T1D, ages 18 to 65 years (n = 45, 60% female, HbA1c, 7.5 ± 1.2%, 20.2 ± 9.3 years duration) without chronic kidney disease (eGFR ≥60 mL/min/1.73 m2 and albumin-to-creatinine ratio < 30 mg/g) received 2 doses of 1950 mg oral NaHCO3 over 24 hours. Fasting urine and serum were collected pre- and post-intervention. UA crystals were identified under polarized microscopy. Urine measurements included: osmolality, pH, UA, creatinine and kidney injury molecule-1 (KIM-1). NaHCO3 therapy increased mean ± SD urine pH from 6.1 ± 0.7 to 6.5 ± 0.7 (P < .0001). Prior to therapy, 31.0% of participants had UA crystals vs 6.7% post therapy (P = .005). Change in urine pH inversely correlated with change in urine KIM-1 (r:-0.51, P = .0003). In addition, change in urine UA over 24 hours correlated with change in urine KIM-1 (r:0.37, P = .01). In conclusion, oral NaHCO3 normalized urine pH and decreased UA crystals, and may hold promise as an inexpensive and safe tubulo-protective intervention in individuals with T1D.

Early diabetic kidney disease (DKD) occurs in adolescents with type 1 diabetes (T1D). Lower serum uromodulin (SUMOD) predicts DKD progression in adults with T1D. In this study, we demonstrate that lower SUMOD is associated with urinary albumin excretion in adolescents with T1D, suggesting a potential relationship between SUMOD and early kidney dysfunction in T1D youth.

Youth with type 1 diabetes (T1D) carry greater cardiovascular disease (CVD) risk than their nondiabetic peers. Low serum uromodulin (SUMOD) associates with increased CVD mortality in adults. We found that T1D youth have low SUMOD. Lower SUMOD correlated with aortic stiffness, suggesting its potential as a CVD biomarker in T1D.

Objective Whether obesity without metabolic syndrome (i.e., “metabolically healthy” obesity) confers similar or less metabolic risk remains controversial. Methods A retrospective 5-year cohort study of 9,721 Japanese subjects (48.5 ± 10.5 years, 4,160 men) was conducted in 2004 and reevaluated 5 years later. Subjects were excluded if they were hypertensive or diabetic or were receiving medications for dyslipidemia and/or gout or hyperuricemia in 2004. Study subjects were categorized according to baseline BMI ≥ 25 kg/m2 (overweight/obesity) and