Estimated Lifetime Cardiovascular, Kidney, and Mortality Benefits of Combination Treatment With SGLT2 Inhibitors, GLP-1 Receptor Agonists, and Nonsteroidal MRA Compared With Conventional Care in Patients With Type 2 Diabetes and Albuminuria.

BACKGROUND: Sodium glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and the nonsteroidal mineralocorticoid receptor antagonist (ns-MRA) finerenone all individually reduce cardiovascular, kidney, and mortality outcomes in patients with type 2 diabetes and albuminuria. However, the lifetime benefits of combination therapy with these medicines are not known. METHODS: We used data from 2 SGLT2i trials (CANVAS [Canagliflozin Cardiovascular Assessment] and CREDENCE [Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation]), 2 ns-MRA trials (FIDELIO-DKD [Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease] and FIGARO-DKD [Efficacy and Safety of Finerenone in Subjects With Type 2 Diabetes Mellitus and the Clinical Diagnosis of Diabetic Kidney Disease]), and 8 GLP-1 RA trials to estimate the relative effects of combination therapy versus conventional care (renin-angiotensin system blockade and traditional risk factor control) on cardiovascular, kidney, and mortality outcomes. Using actuarial methods, we then estimated absolute risk reductions with combination SGLT2i, GLP-1 RA, and ns-MRA in patients with type 2 diabetes and at least moderately increased albuminuria (urinary albumin:creatinine ratio ≥30 mg/g) by applying estimated combination treatment effects to participants receiving conventional care in CANVAS and CREDENCE. RESULTS: Compared with conventional care, the combination of SGLT2i, GLP-1 RA, and ns-MRA was associated with a hazard ratio of 0.65 (95% CI, 0.55-0.76) for major adverse cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death). The corresponding estimated absolute risk reduction over 3 years was 4.4% (95% CI, 3.0-5.7), with a number needed to treat of 23 (95% CI, 18-33). For a 50-year-old patient commencing combination therapy, estimated major adverse cardiovascular event-free survival was 21.1 years compared with 17.9 years for conventional care (3.2 years gained [95% CI, 2.1-4.3]). There were also projected gains in survival free from hospitalized heart failure (3.2 years [95% CI, 2.4-4.0]), chronic kidney disease progression (5.5 years [95% CI, 4.0-6.7]), cardiovascular death (2.2 years [95% CI, 1.2-3.0]), and all-cause death (2.4 years [95% CI, 1.4-3.4]). Attenuated but clinically relevant gains in event-free survival were observed in analyses assuming 50% additive effects of combination therapy, including for major adverse cardiovascular events (2.4 years [95% CI, 1.1-3.5]), chronic kidney disease progression (4.5 years [95% CI, 2.8-5.9]), and all-cause death (1.8 years [95% CI, 0.7-2.8]). CONCLUSIONS: In patients with type 2 diabetes and at least moderately increased albuminuria, combination treatment of SGLT2i, GLP-1 RA, and ns-MRA has the potential to afford relevant gains in cardiovascular and kidney event-free and overall survival.

Glycemia Reduction in Type 2 Diabetes - Microvascular and Cardiovascular Outcomes.

BACKGROUND: Data are lacking on the comparative effectiveness of commonly used glucose-lowering medications, when added to metformin, with respect to microvascular and cardiovascular disease outcomes in persons with type 2 diabetes. METHODS: We assessed the comparative effectiveness of four commonly used glucose-lowering medications, added to metformin, in achieving and maintaining a glycated hemoglobin level of less than 7.0% in participants with type 2 diabetes. The randomly assigned therapies were insulin glargine U-100 (hereafter, glargine), glimepiride, liraglutide, and sitagliptin. Prespecified secondary outcomes with respect to microvascular and cardiovascular disease included hypertension and dyslipidemia, confirmed moderately or severely increased albuminuria or an estimated glomerular filtration rate of less than 60 ml per minute per 1.73 m2 of body-surface area, diabetic peripheral neuropathy assessed with the Michigan Neuropathy Screening Instrument, cardiovascular events (major adverse cardiovascular events [MACE], hospitalization for heart failure, or an aggregate outcome of any cardiovascular event), and death. Hazard ratios are presented with 95% confidence limits that are not adjusted for multiple comparisons. RESULTS: During a mean 5.0 years of follow-up in 5047 participants, there were no material differences among the interventions with respect to the development of hypertension or dyslipidemia or with respect to microvascular outcomes; the mean overall rate (i.e., events per 100 participant-years) of moderately increased albuminuria levels was 2.6, of severely increased albuminuria levels 1.1, of renal impairment 2.9, and of diabetic peripheral neuropathy 16.7. The treatment groups did not differ with respect to MACE (overall rate, 1.0), hospitalization for heart failure (0.4), death from cardiovascular causes (0.3), or all deaths (0.6). There were small differences with respect to rates of any cardiovascular disease, with 1.9, 1.9, 1.4, and 2.0 in the glargine, glimepiride, liraglutide, and sitagliptin groups, respectively. When one treatment was compared with the combined results of the other three treatments, the hazard ratios for any cardiovascular disease were 1.1 (95% confidence interval [CI], 0.9 to 1.3) in the glargine group, 1.1 (95% CI, 0.9 to 1.4) in the glimepiride group, 0.7 (95% CI, 0.6 to 0.9) in the liraglutide group, and 1.2 (95% CI, 1.0 to 1.5) in the sitagliptin group. CONCLUSIONS: In participants with type 2 diabetes, the incidences of microvascular complications and death were not materially different among the four treatment groups. The findings indicated possible differences among the groups in the incidence of any cardiovascular disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; GRADE ClinicalTrials.gov number, NCT01794143.).

A molecular mechanism for angiotensin II receptor blocker-mediated slit membrane protection: Angiotensin II increases nephrin endocytosis via AT1-receptor-dependent ERK 1/2 activation.

Albuminuria is characterized by a disruption of the glomerular filtration barrier, which is composed of the fenestrated endothelium, the glomerular basement membrane, and the slit diaphragm. Nephrin is a major component of the slit diaphragm. Apart from hemodynamic effects, Ang II enhances albuminuria by ß-Arrestin2-mediated nephrin endocytosis. Blocking the AT1 receptor with candesartan and irbesartan reduces the Ang II-mediated nephrin-ß-Arrestin2 interaction. The inhibition of MAPK ERK 1/2 blocks Ang II-enhanced nephrin-ß-Arrestin2 binding. ERK 1/2 signaling, which follows AT1 receptor activation, is mediated by G-protein signaling, EGFR transactivation, and ß-Arrestin2 recruitment. A mutant AT1 receptor defective in EGFR transactivation and ß-Arrestin2 recruitment reduces the Ang II-mediated increase in nephrin ß-Arrestin2 binding. The mutation of ß-Arrestin2K11,K12, critical for AT1 receptor binding, completely abrogates the interaction with nephrin, independent of Ang II stimulation. ß-Arrestin2K11R,K12R does not influence nephrin cell surface expression. The data presented here deepen our molecular understanding of a blood-pressure-independent molecular mechanism of AT-1 receptor blockers (ARBs) in reducing albuminuria.

Blocking CHOP-dependent TXNIP shuttling to mitochondria attenuates albuminuria and mitigates kidney injury in nephrotic syndrome.

Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizing Chop-/- and Txnip-/- mice as well as 68Ga-Galuminox, our molecular imaging probe for detection of mitochondrial reactive oxygen species (ROS) in vivo, we demonstrate that CHOP up-regulation induced by albuminuria drives TXNIP shuttling from nucleus to mitochondria, where it is required for the induction of mitochondrial ROS. The increased ROS accumulation in mitochondria oxidizes Trx2, thus liberating TXNIP to associate with mitochondrial nod-like receptor protein 3 (NLRP3) to activate inflammasome, as well as releasing mitochondrial apoptosis signal-regulating kinase 1 (ASK1) to induce mitochondria-dependent apoptosis. Importantly, inhibition of TXNIP translocation and mitochondrial ROS overproduction by CHOP deletion suppresses NLRP3 inflammasome activation and p-ASK1-dependent mitochondria apoptosis in NS. Thus, targeting TXNIP represents a promising therapeutic strategy for the treatment of NS.

Association of Albuminuria With Chronic Kidney Disease Progression in Persons With Chronic Kidney Disease and Normoalbuminuria : A Cohort Study.

BACKGROUND: Albuminuria is a major risk factor for chronic kidney disease (CKD) progression, especially when categorized as moderate (30 to 300 mg/g) or severe (>300 mg/g). However, there are limited data on the prognostic value of albuminuria within the normoalbuminuric range (<30 mg/g) in persons with CKD. OBJECTIVE: To estimate the increase in the cumulative incidence of CKD progression with greater baseline levels of albuminuria among persons with CKD who had normoalbuminuria (<30 mg/g). DESIGN: Multicenter prospective cohort study. SETTING: 7 U.S. clinical centers. PARTICIPANTS: 1629 participants meeting criteria from the CRIC (Chronic Renal Insufficiency Cohort) study with CKD (estimated glomerular filtration rate [eGFR], 20 to 70 mL/min/1.73 m2) and urine albumin-creatinine ratio (UACR) less than 30 mg/g. MEASUREMENTS: Baseline spot urine albumin divided by spot urine creatinine to calculate UACR as the exposure variable. The 10-year adjusted cumulative incidences of CKD progression (composite of 50% eGFR decline or kidney failure [dialysis or kidney transplantation]) from confounder adjusted survival curves using the G-formula. RESULTS: Over a median follow-up of 9.8 years, 182 of 1629 participants experienced CKD progression. The 10-year adjusted cumulative incidences of CKD progression were 8.7% (95% CI, 5.9% to 11.6%), 11.5% (CI, 8.8% to 14.3%), and 19.5% (CI, 15.4% to 23.5%) for UACR levels of 0 to less than 5 mg/g, 5 to less than 15 mg/g, and 15 mg/g or more, respectively. Comparing persons with UACR 15 mg/g or more to those with UACR 5 to less than 15 mg/g and 0 to less than 5 mg/g, the absolute risk differences were 7.9% (CI, 3.0% to 12.7%) and 10.7% (CI, 5.8% to 15.6%), respectively. The 10-year adjusted cumulative incidence increased linearly based on baseline UACR levels. LIMITATION: UACR was measured once. CONCLUSION: Persons with CKD and normoalbuminuria (<30 mg/g) had excess risk for CKD progression, which increased in a linear fashion with higher levels of albuminuria. PRIMARY FUNDING SOURCE: None.

Application of Proteomics and Machine Learning Methods to Study the Pathogenesis of Diabetic Nephropathy and Screen Urinary Biomarkers.

Diabetic nephropathy (DN) has become the main cause of end-stage renal disease worldwide, causing significant health problems. Early diagnosis of the disease is quite inadequate. To screen urine biomarkers of DN and explore its potential mechanism, this study collected urine from 87 patients with type 2 diabetes mellitus (which will be classified into normal albuminuria, microalbuminuria, and macroalbuminuria groups) and 38 healthy subjects. Twelve individuals from each group were then randomly selected as the screening cohort for proteomics analysis and the rest as the validation cohort. The results showed that humoral immune response, complement activation, complement and coagulation cascades, renin-angiotensin system, and cell adhesion molecules were closely related to the progression of DN. Five overlapping proteins (KLK1, CSPG4, PLAU, SERPINA3, and ALB) were identified as potential biomarkers by machine learning methods. Among them, KLK1 and CSPG4 were positively correlated with the urinary albumin to creatinine ratio (UACR), and SERPINA3 was negatively correlated with the UACR, which were validated by enzyme-linked immunosorbent assay (ELISA). This study provides new insights into disease mechanisms and biomarkers for early diagnosis of DN.

Circulating metabolomic markers linking diabetic kidney disease and incident cardiovascular disease in type 2 diabetes: analyses from the Hong Kong Diabetes Biobank.

AIMS/HYPOTHESIS: The aim of this study was to describe the metabolome in diabetic kidney disease (DKD) and its association with incident CVD in type 2 diabetes, and identify prognostic biomarkers. METHODS: From a prospective cohort of individuals with type 2 diabetes, baseline sera (N=1991) were quantified for 170 metabolites using NMR spectroscopy with median 5.2 years of follow-up. Associations of chronic kidney disease (CKD, eGFR<60 ml/min per 1.73 m2) or severely increased albuminuria with each metabolite were examined using linear regression, adjusted for confounders and multiplicity. Associations between DKD (CKD or severely increased albuminuria)-related metabolites and incident CVD were examined using Cox regressions. Metabolomic biomarkers were identified and assessed for CVD prediction and replicated in two independent cohorts. RESULTS: At false discovery rate (FDR)<0.05, 156 metabolites were associated with DKD (151 for CKD and 128 for severely increased albuminuria), including apolipoprotein B-containing lipoproteins, HDL, fatty acids, phenylalanine, tyrosine, albumin and glycoprotein acetyls. Over 5.2 years of follow-up, 75 metabolites were associated with incident CVD at FDR<0.05. A model comprising age, sex and three metabolites (albumin, triglycerides in large HDL and phospholipids in small LDL) performed comparably to conventional risk factors (C statistic 0.765 vs 0.762, p=0.893) and adding the three metabolites further improved CVD prediction (C statistic from 0.762 to 0.797, p=0.014) and improved discrimination and reclassification. The 3-metabolite score was validated in independent Chinese and Dutch cohorts. CONCLUSIONS/INTERPRETATION: Altered metabolomic signatures in DKD are associated with incident CVD and improve CVD risk stratification.

Comparative renal outcomes of matched cohorts of patients with type 2 diabetes receiving SGLT2 inhibitors or GLP-1 receptor agonists under routine care.

AIMS/HYPOTHESIS: We compared the effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on renal outcomes in individuals with type 2 diabetes, focusing on the changes in eGFR and albuminuria. METHODS: This was a multicentre retrospective observational study on new users of diabetes medications. Participant characteristics were assessed before and after propensity score matching. The primary endpoint, change in eGFR, was analysed using mixed-effects models. Secondary endpoints included categorical eGFR-based outcomes and changes in albuminuria. Subgroup and sensitivity analyses were performed to assess robustness of the findings. RESULTS: After matching, 5701 participants/group were included. Participants were predominantly male, aged 61 years, with a 10 year duration of diabetes, a baseline HbA1c of 64 mmol/mol (8.0%) and BMI of 33 kg/m2. Chronic kidney disease (CKD) was present in 23% of participants. During a median of 2.1 years, from a baseline of 87 ml/min per 1.73 m2, eGFR remained higher in the SGLT2i group compared with the GLP-1RA group throughout the observation period by 1.2 ml/min per 1.73 m2. No differences were detected in albuminuria change. The SGLT2i group exhibited lower rates of worsening CKD class and favourable changes in BP compared with the GLP-1RA group, despite lesser HbA1c decline. SGLT2i also reduced eGFR decline better than GLP-1RA in participants without baseline CKD. CONCLUSIONS/INTERPRETATION: In individuals with type 2 diabetes, treatment with SGLT2i was associated with better preservation of renal function compared with GLP-1RA, as evidenced by slower decline in eGFR. These findings reinforce SGLT2i as preferred agents for renal protection in this patient population.

Renal handling of albumin in rats with early stage diabetes: A theoretical analysis.

In early diabetic nephropathy (DN), recent studies have shown that albuminuria stems mostly from alterations in tubular function rather than from glomerular damage. Several factors in DN, including hyperfiltration, hypertrophy and reduced abundance of the albumin receptors megalin and cubilin, affect albumin endocytosis in the proximal tubule (PT). To assess their respective contribution, we developed a model of albumin handling in the rat PT that couples the transport of albumin to that of water and solutes. Our simulations suggest that, under basal conditions, ∼75% of albumin is retrieved in the S1 segment. The model predicts negligible uptake in S3, as observed experimentally. It also accurately predicts the impact of acute hyperglycaemia on urinary albumin excretion. Simulations reproduce observed increases in albumin excretion in early DN by considering the combined effects of increased glomerular filtration rate (GFR), osmotic diuresis, hypertrophy, and megalin and cubilin downregulation, without stipulating changes in glomerular permselectivity. The results indicate that in isolation, glucose-elicited osmotic diuresis and glucose transporter upregulation raise albumin excretion only slightly. Enlargement of PT diameter not only augments uptake via surface area expansion, but also reduces fluid velocity and thus shear stress-induced stimulation of endocytosis. Overall, our model predicts that downregulation of megalin and cubilin and hyperfiltration both contribute significantly to increasing albumin excretion in rats with early-stage diabetes. The results also suggest that acute sodium-glucose cotransporter 2 inhibition lowers albumin excretion only if GFR decreases sufficiently, and that angiotensin II receptor blockers mitigate urinary albumin loss in early DN in large part by upregulating albumin receptor abundance. KEY POINTS: The urinary excretion of albumin is increased in early diabetic nephropathy (DN). It is difficult to experimentally disentangle the multiple factors that affect the renal handling of albumin in DN. We developed a mathematical model of albumin transport in the rat proximal tubule (PT) to examine the impact of elevated plasma glucose, hyperfiltration, PT hypertrophy and reduced abundance of albumin receptors on albumin uptake and excretion in DN. Our model predicts that glucose-elicited osmotic diuresis per se raises albumin excretion only slightly. Conversely, increases in PT diameter and length favour reduced albumin excretion. Our results suggest that downregulation of the receptors megalin and cubilin in PT cells and hyperfiltration both contribute significantly to increasing albumin excretion in DN. The model helps to better understand the mechanisms underlying urinary loss of albumin in early-stage diabetes, and the impact of specific treatments thereupon.

Cardiorenal Biomarkers, Canagliflozin, and Outcomes in Diabetic Kidney Disease: The CREDENCE Trial.

BACKGROUND: People with type 2 diabetes and albuminuria are at an elevated risk for cardiac and renal events. The optimal biomarkers to aid disease prediction and to understand the benefits of sodium-glucose cotransporter-2 inhibition remain unclear. METHODS: Among 2627 study participants in the CREDENCE trial (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation), concentrations of NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity cardiac troponin T, growth differentiation factor-15, and IGFBP7 (insulin-like growth factor binding protein 7) were measured. The effect of canagliflozin on biomarker concentrations was evaluated. The prognostic potential of each biomarker on the primary outcome (a composite of end-stage kidney disease [dialysis, transplantation, or a sustained estimated glomerular filtration rate of <15 mL·min-1·1.73 m-2], doubling of the serum creatinine level, or renal death or cardiovascular death) was assessed. RESULTS: The median (quartiles 1 and 3) concentration of each biomarker was generally elevated: NT-proBNP, 180 ng/L (82, 442 ng/L); high-sensitivity cardiac troponin T, 19 ng/L (12, 29 ng/L); growth differentiation factor-15, 2595 ng/L (1852, 3775 ng/L); and IGFBP7, 121.8 ng/mL (105.4, 141.5 ng/mL). At 1 year, the biomarkers all rose by 6% to 29% in the placebo arm but only by 3% to 10% in the canagliflozin arm (all P<0.01 in multivariable linear mixed-effect models). Baseline concentrations of each biomarker were strongly predictive of cardiac and renal outcomes. When the biomarkers were analyzed together in a multimarker panel, individuals with high risk scores (hazard ratio [HR], 4.01 [95% CI, 2.52-6.35]) and moderate risk scores (HR, 2.39 [95% CI, 1.48-3.87]) showed a higher risk for the primary outcome compared with those with low risk scores. By 1 year, a 50% increase in NT-proBNP (HR, 1.11 [95% CI, 1.08-1.15]), high-sensitivity cardiac troponin T (HR, 1.86 [95% CI, 1.64-2.10]), growth differentiation factor-15 (HR, 1.45 [95% CI, 1.24-1.70]), and IGFBP7 (HR, 3.76 [95% CI, 2.54-5.56]) was associated with risk of the primary outcome. CONCLUSIONS: Multiple cardiorenal stress biomarkers are strongly prognostic in people with type 2 diabetes and albuminuria. Canagliflozin modestly reduced the longitudinal trajectory of rise in each biomarker. Change in the biomarker level in addition to the baseline level augments the primary outcome prediction. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02065791.

T-cells regulate albuminuria but not hypertension, renal histology, or the medullary transcriptome in the Dahl SSCD247+/+ rat.

In the current study, we took advantage of the loss of protection from hypertension in SSCD247-/- rats to characterize the pathological effects of renal T-cells in isolation from the confounding effects of elevated renal perfusion pressure. Male SSCD247-/- and SSCD247+/+ littermates were fed 4.0% NaCl (high salt) diet to induce hypertension. Blood pressure was assessed continuously throughout the time course with radiotelemetry. Urine albumin and protein excretion were assessed on the final day of high salt. Renal injury and medullary transcriptome were assessed after completion of the high salt protocol. In contrast to previous studies, mean arterial pressure was not significantly different between SSCD247-/- and SSCD247+/+ rats. Despite this lack of pressure difference, urinary albumin was significantly lower in SSCD247-/- rats than their wild-type littermates. In the outer medulla, substantially more transcriptomic changes were found to correlate with endpoint blood pressure than with the absence of presence of renal T-cells. We also demonstrated that renal histological damage was driven by elevated renal perfusion pressure rather than the presence of renal T-cells. In conclusion, using the loss of protection from hypertension in SSCD247-/- rats, we demonstrated that renal perfusion pressure has more profound pathological effects on the kidney than renal T-cells. However, renal T-cells, independently of blood pressure, modulate the progression of albuminuria.NEW & NOTEWORTHY In vivo studies in a T-cell-deficient rat model of salt-sensitive hypertension (SSCD247-/- rats) were used to evaluate the role of T-cells on the development of hypertension and renal damage. Detailed physiological and transcriptomic analysis demonstrated no difference in blood pressure between rats with (SSCD247+/+) or without (SSCD247-/-) T-cells. Despite this, albuminuria was significantly lower in SSCD247-/- rats than SSCD247+/+ rats.

Glucagon receptor activation contributes to the development of kidney injury.

The underlying causes of diabetic kidney disease are still largely unknown. New insights into the contributing causes of diabetic nephropathy are important to prevent this complication. Hyperglycemia and hypertension are some of the risk factors for diabetic nephropathy. However, the incidence of diabetic nephropathy is increasing despite efforts to normalize blood glucose levels and blood pressure. Therefore, other factors should be investigated as causes of diabetic nephropathy. We investigated whether long-term increased plasma levels of glucagon contribute to the development of pathophysiological changes in kidney function as seen in patients with diabetic nephropathy. Using mouse models of chronic activation and inactivation of glucagon receptor signaling, we investigated whether glucagon is involved in changes in renal function, renal structure, and transcriptional changes. We found several histopathological changes in the kidney, such as thickening of the parietal layer of Bowman's capsule, glomerular mesangial cell expansion, and significant albuminuria in the mice with activated glucagon receptor signaling. Opposite effects on mesangial area expansion and the development of albuminuria were demonstrated in mice with glucagon receptor inactivation. RNA sequencing data revealed that transcription of genes related to fatty acid metabolism, podocytes, Na+-K+-ATPase, and sodium/glucose transport was significantly changed in mice with activated glucagon receptor signaling. These data implicate that glucagon receptor signaling is involved in the development of kidney injury, as seen in type 2 diabetes, and that glucagon receptor is a potential therapeutic target in the treatment of diabetes. NEW & NOTEWORTHY This study suggests that the glucagon receptor is a potential therapeutic target in the treatment of diabetic kidney disease. We show, in mice, that long-term treatment with a glucagon analog showed not only pathophysiological changes and changes in renal function but also transcriptional changes in the kidneys, whereas opposite effects were demonstrated in mice with glucagon receptor inactivation. Therefore, the use of glucagon in a treatment regimen requires investigation of possible metabolic and renal abnormalities.

Preventive effects of vasohibin-2-targeting peptide vaccine for diabetic nephropathy.

Diabetic nephropathy remains the leading cause of end-stage kidney disease in many countries, and additional therapeutic targets are needed to prevent its development and progression. Some angiogenic factors are involved in the pathogenesis of diabetic nephropathy. Vasohibin-2 (VASH2) is a novel proangiogenic factor, and our previous study showed that glomerular damage is inhibited in diabetic Vash2 homozygous knockout mice. Therefore, we established a VASH2-targeting peptide vaccine as a tool for anti-VASH2 therapy in diabetic nephropathy. In this study, the preventive effects of the VASH2-targeting peptide vaccine against glomerular injury were examined in a streptozotocin (STZ)-induced diabetic mouse model. The mice were subcutaneously injected with the vaccine at two doses 2 wk apart and then intraperitoneally injected with 50 mg/kg STZ for 5 consecutive days. Glomerular injury was evaluated 20 wk after the first vaccination. Treatment with the VASH2-targeting peptide vaccine successfully induced circulating anti-VASH2 antibody without inflammation in major organs. Although the vaccination did not affect blood glucose levels, it significantly prevented hyperglycemia-induced increases in urinary albumin excretion and glomerular volume. The vaccination did not affect increased VASH2 expression but significantly inhibited renal angiopoietin-2 (Angpt2) expression in the diabetic mice. Furthermore, it significantly prevented glomerular macrophage infiltration. The preventive effects of vaccination on glomerular injury were also confirmed in db/db mice. Taken together, the results of this study suggest that the VASH2-targeting peptide vaccine may prevent diabetic glomerular injury in mice by inhibiting Angpt2-mediated microinflammation.NEW & NOTEWORTHY This study demonstrated preventive effects of VASH2-targeting peptide vaccine therapy on albuminuria and glomerular microinflammation in STZ-induced diabetic mouse model by inhibiting renal Angpt2 expression. The vaccination was also effective in db/db mice. The results highlight the importance of VASH2 in the pathogenesis of early-stage diabetic nephropathy and the practicability of anti-VASH2 strategy as a vaccine therapy.

Fasting mimicking diet in diabetic mice partially preserves glomerular endothelial glycocalyx coverage, without changing the diabetic metabolic environment.

Intermittent fasting has become of interest for its possible metabolic benefits and reduction of inflammation and oxidative damage, all of which play a role in the pathophysiology of diabetic nephropathy. We tested in a streptozotocin (60 mg/kg)-induced diabetic apolipoprotein E knockout mouse model whether repeated fasting mimicking diet (FMD) prevents glomerular damage. Diabetic mice received 5 FMD cycles in 10 wk, and during cycles 1 and 5 caloric measurements were performed. After 10 wk, glomerular endothelial morphology was determined together with albuminuria, urinary heparanase-1 activity, and spatial mass spectrometry imaging to identify specific glomerular metabolic dysregulation. During FMD cycles, blood glucose levels dropped while a temporal metabolic switch was observed to increase fatty acid oxidation. Overall body weight at the end of the study was reduced together with albuminuria, although urine production was dramatically increased without affecting urinary heparanase-1 activity. Weight loss was found to be due to lean mass and water, not fat mass. Although capillary loop morphology and endothelial glycocalyx heparan sulfate contents were preserved, hyaluronan surface expression was reduced together with the presence of UDP-glucuronic acid. Mass spectrometry imaging further revealed reduced protein catabolic breakdown products and increased oxidative stress, not different from diabetic mice. In conclusion, although FMD preserves partially glomerular endothelial glycocalyx, loss of lean mass and increased glomerular oxidative stress argue whether such diet regimes are safe in patients with diabetes.NEW & NOTEWORTHY Repeated fasting mimicking diet (FMD) partially prevents glomerular damage in a diabetic mouse model; however, although endothelial glycocalyx heparan sulfate contents were preserved, hyaluronan surface expression was reduced in the presence of UDP-glucuronic acid. The weight loss observed was of lean mass, not fat mass, and increased glomerular oxidative stress argue whether such a diet is safe in patients with diabetes.

Effects of Dipeptidyl Peptidase-4 Inhibitor and Angiotensin-Converting Enzyme Inhibitor on Experimental Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease in the United States and worldwide. Proteinuria is a major marker of the severity of injury. Dipeptidyl peptidase-4 inhibitor (DPP-4I) increases incretin-related insulin production and is, therefore, used to treat diabetes. We investigated whether DPP4I could have direct effect on kidney independent of its hypoglycemic activity. We, therefore, tested the effects of DPP4I with or without angiotensin-converting enzyme inhibitor (ACEI) on the progression of diabetic nephropathy and albuminuria in a murine model of DKD. eNOS-/-db/db mice were randomized to the following groups at age 10 weeks and treated until sacrifice: baseline (sacrificed at week 10), untreated control, ACEI, DPP4I, and combination of DPP4I and ACEI (Combo, sacrificed at week 18). Systemic parameters and urine albumin-creatinine ratio were assessed at baseline, weeks 14, and 18. Kidney morphology, glomerular filtration rate (GFR), WT-1, a marker for differentiated podocytes, podoplanin, a marker of foot process integrity, glomerular collagen IV, and alpha-smooth muscle actin were assessed at the end of the study. All mice had hyperglycemia and proteinuria at study entry at week 10. Untreated control mice had increased albuminuria, progression of glomerular injury, and reduced GFR at week 18 compared with baseline. DPP4I alone reduced blood glucose and kidney DPP-4 activity but failed to protect against kidney injury compared with untreated control. ACEI alone and combination groups showed significantly reduced albuminuria and glomerular injury, and maintained GFR and WT-1+ cells. Only the combination group had significantly less glomerular collagen IV deposition and more podoplanin preservation than the untreated control. DPP-4I alone does not decrease the progression of kidney injury in the eNOS-/-db/db mouse model, suggesting that targeting only hyperglycemia is not an optimal treatment strategy for DKD. Combined DPP-4I with ACEI added more benefit to reducing the glomerular matrix.

Pediatric kidney dimensions and risk of persistent albuminuria in Mexican adolescents.

In Mexico, chronic kidney disease of unknown origin is highly prevalent. Screening studies in adolescents have shown persistent microalbuminuria (pACR), adaptive podocytopathy and decreased kidney volume (KV). Here, we sought to develop normality tables of kidney dimensions by ultrasound in the Mexican state of Aguascalientes pediatric population (0 to 18y) and evaluate the relationship between the KV and pACR among the region's adolescents in a cross-sectional study. Kidney length (KL) and KV were determined by ultrasound. Our findings were compared with those in international literature of different populations where tables and graphs of normal kidney dimensions by ultrasound were reported. We compared organ dimensions in individuals above the age of 11 without albuminuria with those in patients with pACR recruited through screening studies in adolescents in Aguascalientes. This included 1068 individuals to construct percentile tables and graphs of the KL. Kidney dimensions were significantly lower when compared with all international comparisons. From a total 14,805 screen individuals, we compared 218 adolescents with pACR and 377 individuals without significant albuminuria. The Total KV adjusted to body surface (TKVBS) was significantly associated with pACR (odds ratio 1.03, 95% confidence interval 1.02-1.03). The upper quartile of TKVBS was highly associated with pACR (7.57, 4.13-13.87), hypertension (2.53, 1.66-3.86), and hyperfiltration (26 vs 11.5%). Thus, TKVBS is directly associated with pACR while greater KV, arterial hypertension, and hyperfiltration in patients with pACR suggest that the increase in volume is secondary to kidney hypertrophy. Additionally, the adaptative podocytopathy with low fibrosis seen on kidney biopsy which was performed in a subset of patients, and the smaller kidney dimensions in our population point to prenatal oligonephronia as the primary cause of the detected kidney disease.

A randomized, open-label, clinical trial examined the effects of canagliflozin on albuminuria and eGFR decline using an individual pre-intervention eGFR slope.

Demonstrating drug efficacy in slowing kidney disease progression requires large clinical trials when targeting participants with an early stage of chronic kidney disease (CKD). In this randomized, parallel-group, open-labeled trial (CANPIONE study), we assessed the effect of the sodium-glucose cotransporter 2 (SGLT2) inhibitor canagliflozin using the individual's change in estimated glomerular filtration rate (eGFR) slope before (pre-intervention slope) and during treatment (chronic slope). We randomly assigned (1:1) participants with type 2 diabetes, urinary albumin-to-creatinine ratio (UACR) of 50 to under 300 mg/g, and an eGFR of at least 45 ml/min/1.73m2 to receive canagliflozin or guideline-recommended treatment except for SGLT2 inhibitors (control). The first and second primary outcomes were the geometric mean percentage change from baseline in UACR and the change in eGFR slope, respectively. Of 98 randomized participants, 96 received at least one study treatment. The least-squares mean change from baseline in log-transformed geometric mean UACR was significantly greater in the canagliflozin group than the control group (between group-difference, -30.8% (95% confidence interval -42.6 to -16.8). The between-group difference (canagliflozin group - control group) of change in eGFR slope (chronic - pre-intervention) was 4.4 (1.6 to 7.3) ml/min/1.73 m2 per year, which was more pronounced in participants with faster eGFR decline. In summary, canagliflozin reduced albuminuria and the participant-specific natural course of eGFR decline in participants with type 2 diabetes and microalbuminuria. Thus, the CANPIONE study suggests that the within-individual change in eGFR slope may be a novel approach to determine the kidney protective potential of new therapies in early stages of CKD.

Long-term impact of immediate versus deferred antiretroviral therapy on kidney health in people with HIV.

People with human immunodeficiency virus (HIV) are at risk for chronic kidney disease (CKD) due to HIV and antiretroviral therapy (ART) nephrotoxicity. Immediate ART initiation reduces mortality and is now the standard of care, but the long-term impact of prolonged ART exposure on CKD is unknown. To evaluate this, the Strategic Timing of Antiretroviral Treatment (START) trial randomized 4,684 ART-naïve adults with CD4 cell count under 500 cells/mm3 to immediate versus deferred ART. We previously reported a small but statistically significantly greater decline in estimated glomerular filtration rate (eGFR) over a median of 2.1 years in participants randomized to deferred versus immediate ART. Here, we compare the incidence of CKD events and changes in eGFR and urine albumin/creatinine ratio (UACR) in participants randomized to immediate versus deferred ART during extended follow-up. Over a median of 9.3 years, eight participants experienced kidney failure or kidney-related death, three in the immediate and five in the deferred ART arms, respectively. Over a median of five years of more comprehensive follow-up, the annual rate of eGFR decline was 1.19 mL/min/1.73m2/year, with no significant difference between treatment arms (difference deferred - immediate arm 0.055; 95% confidence interval -0.106, 0.217 mL/min/1.73m2). Results were similar in models adjusted for baseline covariates associated with CKD, including UACR and APOL1 genotype. Similarly, there was no significant difference between treatment arms in incidence of confirmed UACR 30 mg/g or more (odds ratio 1.13; 95% confidence interval 0.85, 1.51). Thus, our findings provide the most definitive evidence to date in support of the long-term safety of early ART with respect to kidney health.

Persistent albuminuria and chronic kidney disease in adults with sickle cell anaemia: Results from a multicenter natural history study.

Clinical and laboratory correlates of chronic kidney disease (CKD) in sickle cell anaemia remain incompletely defined. In a multicenter cohort study, we evaluated the prevalence of persistent albuminuria (PA) and characteristics associated with PA, albumin-creatinine ratio (ACR) and decreased estimated glomerular filtration rate (eGFR) using logistic, linear and multinomial regression models, respectively. Of 269 participants (median age: 30 years; 57.2% females), the prevalence of PA was 35.7%. Using baseline ACR values of <100 and ≥100 mg/g, the probabilities of PA were 30.0% and 94.6%, respectively. In multivariable logistic regression analyses, male sex (ß = 0.80 [SE = 0.36], p = 0.024) and ACE inhibitors/ARBs use (ß = 1.54 [SE = 0.43], p < 0.001) were associated with higher likelihoods of PA, while higher haemoglobin (ß = -0.33 [SE = 0.13], p = 0.009) and HbF (ß = -0.04 [SE = 0.02], p = 0.041) were associated with lower likelihoods of PA. In multivariable multinomial regression analyses, older age (ß = 0.06 [SE = 0.02], p = 0.004) and higher alkaline phosphatase (ß = 0.01 [SE = 0.00], p = 0.004) were associated with higher odds of having eGFR 60-90 versus eGFR>90 mL/min/1.73 m2 using the cystatin C-based CKD-EPI-2012 equation. Additionally, higher systolic blood pressure (ß = 0.11 [SE = 0.03], p = 0.001) and blood urea nitrogen (ß = 0.45 [SE = 0.12], p < 0.001) were associated with higher odds, while higher haemoglobin (ß = -1.22 [SE = 0.43], p = 0.004) was associated with lower odds of having eGFR<60 versus eGFR>90 mL/min/1.73 m2. PA and decreased eGFR are associated with measures of disease severity and comorbid conditions (Clinicaltrials.gov Identifier: NCT03277547).

Relevance of repeated analyses of albuminuria and glomerular filtration rate in African children with sickle cell anaemia.

Glomerular hyperfiltration and albuminuria are frequent kidney abnormalities in children with sickle cell anaemia (SCA). However, little is known about their persistence in African SCA children. This prospective study included 600 steady-state SCA children aged 2-18 years from the Democratic Republic of Congo. Participants were genotyped for apolipoprotein L1 (APOL1) risk variants (RVs) and haem oxygenase-1 (HMOX1) GT-dinucleotide repeats. Kidney abnormalities were defined as albuminuria, hyperfiltration or decreased estimated creatinine-based glomerular filtration rate (eGFRcr). At baseline, 247/600 (41.2%) participants presented with kidney abnormalities: 82/592 (13.8%) with albuminuria, 184/587 (31.3%) with hyperfiltration and 15/587 (2.6%) with decreased eGFRcr. After a median follow-up of 5 months, repeated testing was performed in 180/247 (72.9%) available participants. Persistent hyperfiltration and persistent albuminuria (PA) were present in 29.2% (38/130) and 39.7% (23/58) respectively. eGFR normalized in all participants with a baseline decreased eGFRcr. Haemoglobinuria (p = 0.017) and male gender (p = 0.047) were significantly associated with PA and persistent hyperfiltration respectively. APOL1 RVs (G1G1/G2G2/G1G2) were borderline associated with PA (p = 0.075), while HMOX1 long repeat was not associated with any persistent kidney abnormality. This study reveals that a single screening can overestimate the rate of kidney abnormalities in children with SCA and could lead to overtreatment.