Tangshen formula protects against podocyte apoptosis via enhancing the TFEB-mediated autophagy-lysosome pathway in diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease and currently there are no specific and effective drugs for its treatment. Podocyte injury is a detrimental feature and the major cause of albuminuria in DN. We previously reported Tangshen Formula (TSF), a Chinese herbal medicine, has shown therapeutic effects on DN. However, the underlying mechanisms remain obscure.

AIM OF THE STUDY

This study aimed to explore the protective effect of TSF on podocyte apoptosis in DN and elucidate the potential mechanism.

MATERIALS AND METHODS

The effects of TSF were assessed in a murine model using male KKAy diabetic mice, as well as in advanced glycation end products-stimulated primary mice podocytes. Transcription factor EB (TFEB) knockdown primary podocytes were employed for mechanistic studies. In vivo and in vitro studies were performed and results assessed using transmission electron microscopy, immunofluorescence staining, and western blotting.

RESULTS

TSF treatment alleviated podocyte apoptosis and structural impairment, decreased albuminuria, and mitigated renal dysfunction in KKAy mice. Notably, TSF extracted twice showed a more significant reduction in proteinuria than TSF extracted three times. Accumulation of autophagic biomarkers p62 and LC3, and aberrant autophagic flux in podocytes of DN mice were significantly altered by TSF therapy. Consistent with the in vivo results, TSF prevented the apoptosis of primary podocytes exposed to AGEs and activated autophagy. However, the anti-apoptosis capacity of TSF was countered by the autophagy-lysosome inhibitor chloroquine. We found that TSF increased the nuclear translocation of TFEB in diabetic podocytes, and thus upregulated transcription of its several autophagic target genes. Pharmacological activation of TFEB by TSF accelerated the conversion of autophagosome to autolysosome and lysosomal biogenesis, further augmented autophagic flux. Conversely, TFEB knockdown negated the favorable effects of TSF on autophagy in AGEs-stimulated primary podocytes.

CONCLUSIONS

These findings indicate TSF appears to attenuate podocyte apoptosis and promote autophagy in DN via the TFEB-mediated autophagy-lysosome system. Thus, TSF may be a therapeutic candidate for DN.

Cyclooxygenase-2 inhibition prevents renal toxicity but not hypertension during sunitinib treatment

BACKGROUND

Anticancer angiogenesis inhibitors cause hypertension and renal injury. Previously we observed in rats that high-dose aspirin (capable of blocking cyclooxygenase (COX)-1 and-2) was superior to low-dose aspirin (blocking COX-1 only) to prevent these side-effects during treatment with the angiogenesis inhibitor sunitinib, suggesting a role for COX-2. High-dose aspirin additionally prevented the rise in COX-derived prostacyclin (PGI2). Therefore, we studied the preventive effects of selective COX-2 inhibition and the hypothesized contributing role of PGI2 during angiogenesis inhibition.

METHODS

Male WKY rats received vehicle, sunitinib ((SU), 14 mg/kg/day) alone or combined with COX-2 inhibition (celecoxib, 10 mg/kg/day) or a PGI2 analogue (iloprost, 100 μg/kg/day) for 8 days (n = 8-9 per group). Mean arterial pressure (MAP) was measured via radiotelemetry, biochemical measurements were performed via ELISA and vascular function was assessed via wire myography.

RESULTS

SU increased MAP (17±1mmHg versus 3±1mmHg after vehicle on day 4, P < 0.002), which could not be significantly blunted by celecoxib (+12±3mmHg on day 4, P = 0.247), but was temporarily attenuated by iloprost (treatment days 1 + 2 only). Urinary PGI2 (996 ± 112 versus 51 ± 11ng/24h after vehicle, P < 0.001), but not circulating PGI2 increased during SU, which remained unaffected by celecoxib and iloprost. Celecoxib reduced sunitinib-induced albuminuria (0.36 ± 0.05 versus 0.58 ± 0.05mg/24h after SU, P = 0.005). Wire myography demonstrated increased vasoconstriction to endothelin-1 after SU (Emax P = 0.005 versus vehicle), which remained unaffected by celecoxib or iloprost.

CONCLUSION

Selective COX-2 inhibition ameliorates albuminuria during angiogenesis inhibition with sunitinib, which most likely acts independently of PGI2. To combat angiogenesis inhibitor-induced hypertension, dual rather than selective COX-1/2 blockade seems preferential.

A diet containing cod backbone proteins attenuated the development of mesangial sclerosis and tubular dysfunction in male obese BTBR ob/ob mice

PURPOSE

The obese black and tan, brachyuric (BTBR) ob/ob mouse spontaneously develops features comparable to human diabetic nephropathy. The primary aim of the present study was to investigate if a diet containing fish proteins would attenuate or delay the development of glomerular hypertrophy (glomerulomegaly), mesangial sclerosis and albuminuria in obese BTBR ob/ob mice.

METHODS

Obese BTBR.CgLepob/WiscJ male mice were fed diets containing 25% of protein from Atlantic cod backbones and 75% of protein from casein (Cod-BB group), or casein as the sole protein source (control group). Kidneys were analysed morphologically, and markers for renal dysfunction were analysed biochemically in urine and serum.

RESULTS

The Cod-BB diet attenuated the development of mesangial sclerosis (P 0.040) without affecting the development of glomerular hypertrophy and albuminuria. The urine concentration of cystatin C (relative to creatinine) was lower in mice fed the Cod-BB diet (P 0.0044).

CONCLUSION

A diet containing cod backbone protein powder attenuated the development of mesangial sclerosis and tubular dysfunction in obese BTBR ob/ob mice, but did not prevent the development of glomerular hypertrophy and albuminuria in these mice.

Mediators between canagliflozin and renoprotection vary depending on patient characteristics: Insights from the CREDENCE trial

AIM

To identify the mediators between canagliflozin and renoprotection in patients with type 2 diabetes at a high risk of end-stage kidney disease (ESKD).

METHODS

In this post hoc analysis of the CREDENCE trial, the effect of canagliflozin on potential mediators (42 biomarkers) at 52 weeks and the association between changes in mediators and renal outcomes were evaluated using mixed-effects and Cox models, respectively. The renal outcome was a composite of ESKD, serum creatinine doubling or renal death. The percentage of the mediating effect of each significant mediator was calculated based on changes in the hazard ratios of canagliflozin after additional adjustment of the mediator.

RESULTS

Changes in haematocrit, haemoglobin, red blood cell (RBC) count and urinary albumin-to-creatinine ratio (UACR) at 52 weeks significantly mediated 47%, 41%, 40% and 29% risk reduction with canagliflozin, respectively. Further, 85% mediation was attributed to the combined effect of haematocrit and UACR. A large variation in mediating effects by haematocrit change existed among the subgroups, ranging from 17% in those patients with a UACR of more than 3000 mg/g to 63% in patients with a UACR of 3000 mg/g or less. In the subgroups with a UACR of more than 3000 mg/g, UACR change was the highest mediating factor (37%), driven by the strong association between UACR decline and renal risk reduction.

CONCLUSIONS

The renoprotective effects of canagliflozin in patients at a high risk of ESKD can be significantly explained by changes in RBC variables and UACR. The complementary mediating effects of RBC variables and UACR may support the renoprotective effect of canagliflozin in different patient groups.

Myeloid expression of the anti-apoptotic protein Mcl1 is required in anti-myeloperoxidase vasculitis but myeloperoxidase inhibition is not protective

Antibodies to neutrophil and monocyte myeloperoxidase and proteinase 3 are a feature of anti-neutrophil cytoplasmic antibody vasculitis, a disease with significant morbidity for which new treatments are needed. Mice with a myeloid-specific deletion of the anti-apoptotic protein Mcl1 have reduced numbers of circulating neutrophils. Here, we assessed if myeloid-specific Mcl1 was required in murine anti-myeloperoxidase vasculitis and whether inhibition of myeloperoxidase was protective. In a murine model of anti-neutrophil cytoplasmic antibody vasculitis, induced by anti-myeloperoxidase antibody, mice with a myeloid-specific deletion of Mcl1 were protected from disease. They had fewer crescents, neutrophils, and macrophages in the glomeruli, lower serum creatinine levels and reduced albuminuria compared with controls. At baseline and day six after disease induction they had fewer circulating neutrophils than controls. At day six there were also fewer circulating monocytes. Myeloperoxidase inhibition with AZD5904 had no effect on histological or biochemical parameters of disease, and there was also no reduction in albuminuria at day one, two, five or seven after disease induction. These findings persisted when disease was induced without granulocyte-colony stimulating factor, which increases disease severity. A second myeloperoxidase inhibitor, AZM198, also showed no evidence of an effect, although both AZD5904 and AZM198 inhibited human neutrophil extracellular trap formation in vitro. Thus, our results show that while myeloid-specific Mcl1 is required in this model of anti-myeloperoxidase vasculitis, myeloperoxidase inhibition is not protective.

Role of Axl in target organ inflammation and damage due to hypertensive aortic remodeling

We have shown that excessive endothelial cell stretch causes release of growth arrest-specific 6 (GAS6), which activates the tyrosine kinase receptor Axl on monocytes and promotes immune activation and inflammation. We hypothesized that GAS6/Axl blockade would reduce renal and vascular inflammation and lessen renal dysfunction in the setting of chronic aortic remodeling. We characterized a model of aortic remodeling in mice following a 2-wk infusion of angiotensin II (ANG II). These mice had chronically increased pulse wave velocity, and their aortas demonstrated increased mural collagen. Mechanical testing revealed a marked loss of Windkessel function that persisted for 6 mo following ANG II infusion. Renal function studies showed a reduced ability to excrete a volume load, a progressive increase in albuminuria, and tubular damage as estimated by periodic acid Schiff staining. Treatment with the Axl inhibitor R428 beginning 2 mo after ANG II infusion had a minimal effect on aortic remodeling 2 mo later but reduced the infiltration of T cells, γ/δ T cells, and macrophages into the aorta and kidney and improved renal excretory capacity, reduced albuminuria, and reduced evidence of renal tubular damage. In humans, circulating Axl+/Siglec6+ dendritic cells and phospho-Axl+ cells correlated with pulse wave velocity and aortic compliance measured by transesophageal echo, confirming chronic activation of the GAS6/Axl pathway. We conclude that brief episodes of hypertension induce chronic aortic remodeling, which is associated with persistent low-grade inflammation of the aorta and kidneys and evidence of renal dysfunction. These events are mediated at least in part by GAS6/Axl signaling and are improved with Axl blockade.NEW & NOTEWORTHY In this study, a brief, 2-wk period of hypertension in mice led to progressive aortic remodeling, an increase in pulse wave velocity, and evidence of renal injury, dysfunction, and albuminuria. This end-organ damage was associated with persistent renal and aortic infiltration of CD8+ and γ/δ T cells. We show that this inflammatory response is likely due to GAS6/Axl signaling and can be ameliorated by blocking this pathway. We propose that the altered microvascular mechanical forces caused by increased pulse wave velocity enhance GAS6 release from the endothelium, which in turn activates Axl on myeloid cells, promoting the end-organ damage associated with aortic stiffening.

Low-dose hydralazine reduces albuminuria and glomerulosclerosis in a mouse model of obesity-related chronic kidney disease

AIM

To determine, using a mouse model of obesity, whether low-dose hydralazine prevents obesity-related chronic kidney disease (CKD).

METHODS

From 8 weeks of age, male C57BL/6 mice received a high-fat diet (HFD) or chow, with or without low-dose hydralazine (25 mg/L) in drinking water, for 24 weeks. Biometric and metabolic variables, renal function and structural changes, renal global DNA methylation, DNA methylation profile and markers of renal fibrosis, injury, inflammation and oxidative stress were assessed.

RESULTS

The HFD-fed mice developed obesity, with glucose intolerance, hyperinsulinaemia and dyslipidaemia. Obesity increased albuminuria and glomerulosclerosis, which were significantly ameliorated by low-dose hydralazine in the absence of a blood pressure-lowering effect. Obesity increased renal global DNA methylation and this was attenuated by low-dose hydralazine. HFD-induced changes in methylation of individual loci were also significantly reversed by low-dose hydralazine. Obese mice demonstrated increased markers of kidney fibrosis, inflammation and oxidative stress, but these markers were not significantly improved by hydralazine.

CONCLUSION

Low-dose hydralazine ameliorated HFD-induced albuminuria and glomerulosclerosis, independent of alterations in biometric and metabolic variables or blood pressure regulation. Although the precise mechanism of renoprotection in obesity is unclear, an epigenetic basis may be implicated. These data support repurposing hydralazine as a novel therapy to prevent CKD progression in obese patients.

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.).

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 Between SGLT2 Inhibitors vs DPP4 Inhibitors and Renal Outcomes Among Patients With Type 2 Diabetes

CONTEXT

Diabetic kidney disease is a major burden among diabetic patients. Sodium-glucose cotransporter 2 inhibitors (SGLT2is) were shown to reduce renal outcomes in clinical trials and real-world studies. However, head-to-head comparisons with individual classes of glucose-lowering agents warranted further investigation.

OBJECTIVE

This work aimed to investigate the associations between SGLT2is use vs dipeptidyl peptidase-4 inhibitors (DPP4is) use and 4 renal outcomes: end-stage renal disease (ESRD), albuminuria, acute renal failure (ARF), and the rate of estimated glomerular filtration rate (eGFR) change using a territory-wide electronic medical database in Hong Kong.

METHODS

For this retrospective cohort study, the "prevalent new-user" design was adopted to account for previous exposure to study drugs. Propensity score matching was used to balance baseline characteristics. Electronic health data of type 2 diabetes patients using SGLT2is and DPP4is between 2015 and 2018 were collected.

RESULTS

The matched cohort consisted of 6333 SGLT2is users and 25 332 DPP4is users, with a median follow-up of 3.8 years. Compared to DPP4is, SGLT2is use was associated with lower risks of ESRD (hazard ratio [HR]: 0.51; 95% CI, 0.42-0.62; P < .001) and ARF (HR: 0.59; 95% CI, 0.48-0.73; P < .001), and a slower decline in eGFR. The associations remained statistically significant among patients with or without rapid eGFR decline and patients who added or switched to SGLT2is from DPP4is. The association with albuminuria was inconsistent across analyses.

CONCLUSION

Compared to DPP4is, SGLT2is use was associated with reduced risks of ESRD and ARF, and a slower eGFR decline in a real-world setting. The associations remained statistically significant in patients with or without preindex rapid eGFR decline.

The efficacy of pioglitazone for renal protection in diabetic kidney disease

There is limited information on the efficacy of pioglitazone in diabetic kidney diseases (DKD). We evaluated whether pioglitazone exerts renal-protective effects in DKD patients. We designed a retrospective cohort study, which included 742 type 2 diabetes mellitus (T2DM) patients with DKD in Taiwan, with eGFR between 30 and 90 ml/min/1.73 m² and UACR level 300–5000 mg/g. Patients not meeting the target range for HbA1c (above 7%) were given additional medication with pioglitazone (n = 111) or received standard care (non-pioglitazone group, n = 631). The primary endpoint was the occurrence of composite renal endpoints, which was defined as sustained eGFR<15 ml/min/1.73 m² (confirmed by two measurements within 90 days); doubling of serum creatinine (compared to baseline); and the presence of hemodialysis or renal transplantation. The median follow-up duration was two years. At baseline, the mean HbA1C levels in the pioglitazone and non-pioglitazone groups were 8.8% and 8.1%, respectively; mean ages were 64.4 and 66.2 years old, respectively; diabetes durations were 14.3 and 12.3 years, respectively. Baseline eGFR showed no significant difference between the pioglitazone and non-pioglitazone groups (55.8 and 58.8 mL/min/1.73 m², respectively). In terms of gender, 63% of patients were male in the pioglitazone group compared with 57% in the non-pioglitazone group. Pioglitazone use did not reduce the risk of composite renal endpoints in DKD patients (HR: 0.97, 95% CI = 0.53–1.77), including persistent eGFR<15 ml/min/1.73 m² (HR = 1.07, 95% CI = 0.46–2.52), doubling of serum creatinine (HR = 0.97, 95% CI = 0.53–1.77), or ESRD (HR = 2.58, 95% CI = 0.29–23.04). The results were not changed after various adjustments. A non-significant albuminuria reduction was also noted after pioglitazone prescription in DKD patients. Further randomized controlled studies are needed to establish the effects of pioglitazone definitively.

The Renoprotective Effect of Linagliptin in Type 2 Diabetic Patients with Severely Increased Albuminuria

INTRODUCTION

Previous studies have suggested that linagliptin may represent renoprotective effects besides its anti-hyperglycemic properties in patients with type 2 diabetes. However, there is a lack of decisive evidence to support this assumption. This study aimed to address the effect of linagliptin in type 2 diabetic patients with severely increased albuminuria.

METHODS

In this randomized double-blind, placebo-controlled clinical trial, type 2 diabetic patients with severely increased albuminuria (albuminuria ≥ 300 mg/24 h) were enrolled. Patients were randomized to linagliptin (5 mg/d) and placebo based on a computer-generated list of random numbers. Biochemical (fasting blood sugar (FBS) (mg/dL), hemoglobin A1c (HbA1c) (%), proteinuria (mg/24h), blood urea nitrogen (BUN) (mg/dL), serum creatinine (mg/dL)) and clinical variables (weight (kg), systolic, and diastolic blood pressure (mmHg)) were measured at baseline and 3 and 6 months post intervention.

RESULTS

At baseline, no statistically significant difference was detected in demographic characteristics between the two groups (P > .05). A significant decrease was observed in proteinuria, FBS, weight, SBP, and DBP in the intervention group after 6 months (Ptime < .05), however; none of the clinical and biochemical variables showed a significant difference between groups after 6 months (Pgroup > .05).

CONCLUSION

Linagliptin may serve as a renoprotective therapeutic option in diabetic patients with severely increased albuminuria due to its role in proteinuria reduction. Results of this study can be used for future large-scale, long-term studies investigating the renoprotective effects of linagliptin in patients with diabetic nephropathy. DOI: 10.52547/ijkd.6110.

Selective ETA vs. dual ETA/B receptor blockade for the prevention of sunitinib-induced hypertension and albuminuria in WKY rats

AIMS

Although effective in preventing tumour growth, angiogenesis inhibitors cause off-target effects including cardiovascular toxicity and renal injury, most likely via endothelin (ET)-1 up-regulation. ET-1 via stimulation of the ETA receptor has pro-hypertensive actions whereas stimulation of the ETB receptor can elicit both pro- or anti-hypertensive effects. In this study, our aim was to determine the efficacy of selective ETA vs. dual ETA/B receptor blockade for the prevention of angiogenesis inhibitor-induced hypertension and albuminuria.

METHODS AND RESULTS

Male Wistar Kyoto (WKY) rats were treated with vehicle, sunitinib (angiogenesis inhibitor; 14 mg/kg/day) alone or in combination with macitentan (ETA/B receptor antagonist; 30 mg/kg/day) or sitaxentan (selective ETA receptor antagonist; 30 or 100 mg/kg/day) for 8 days. Compared with vehicle, sunitinib treatment caused a rapid and sustained increase in mean arterial pressure of ∼25 mmHg. Co-treatment with macitentan or sitaxentan abolished the pressor response to sunitinib. Sunitinib did not induce endothelial dysfunction. However, it was associated with increased aortic, mesenteric, and renal oxidative stress, an effect that was absent in mesenteric arteries of the macitentan and sitaxentan co-treated groups. Albuminuria was greater in the sunitinib- than vehicle-treated group. Co-treatment with sitaxentan, but not macitentan, prevented this increase in albuminuria. Sunitinib treatment increased circulating and urinary prostacyclin levels and had no effect on thromboxane levels. These increases in prostacyclin were blunted by co-treatment with sitaxentan.

CONCLUSIONS

Our results demonstrate that both selective ETA and dual ETA/B receptor antagonism prevents sunitinib-induced hypertension, whereas sunitinib-induced albuminuria was only prevented by selective ETA receptor antagonism. In addition, our results uncover a role for prostacyclin in the development of these effects. In conclusion, selective ETA receptor antagonism is sufficient for the prevention of sunitinib-induced hypertension and renal injury.

Transcriptional Suppression of Diabetic Nephropathy with Novel Gene Silencer Pyrrole-Imidazole Polyamides Preventing USF1 Binding to the TGF-β1 Promoter

Upstream stimulatory factor 1 (USF1) is a transcription factor that is increased in high-glucose conditions and activates the transforming growth factor (TGF)-β1 promoter. We examined the effects of synthetic pyrrole-imidazole (PI) polyamides in preventing USF1 binding on the TGF-β1 promoter in Wistar rats in which diabetic nephropathy was established by intravenous administration of streptozotocin (STZ). High glucose induced nuclear localization of USF1 in cultured mesangial cells (MCs). In MCs with high glucose, USF1 PI polyamide significantly inhibited increases in promoter activity of TGF-β1 and expression of TGF-β1 mRNA and protein, whereas it significantly decreased the expression of osteopontin and increased that of h-caldesmon mRNA. We also examined the effects of USF1 PI polyamide on diabetic nephropathy. Intraperitoneal injection of USF1 PI polyamide significantly suppressed urinary albumin excretion and decreased serum urea nitrogen in the STZ-diabetic rats. USF1 PI polyamide significantly decreased the glomerular injury score and tubular injury score in the STZ-diabetic rats. It also suppressed the immunostaining of TGF-β1 in the glomerulus and proximal tubules and significantly decreased the expression of TGF-β1 protein from kidney in these rats. These findings indicate that synthetic USF1 PI polyamide could potentially be a practical medicine for diabetic nephropathy.

Renoprotective effect of GLP-1 receptor agonist, liraglutide, in early-phase diabetic kidney disease in spontaneously diabetic Torii fatty rats

BACKGROUND

The aim of this study is to investigate the renoprotective effect of the GLP-1 receptor agonist, liraglutide, in early-phase diabetic kidney disease (DKD) using an animal model of type 2 diabetes with several metabolic disorders.

METHODS

Male 8-week-old spontaneously diabetic Torii (SDT) fatty rats (n = 19) were randomly assigned to three groups. The liraglutide group (n = 6) was injected subcutaneously with liraglutide. Another treatment group (n = 6) received subcutaneous insulin against hyperglycemia and hydralazine against hypertension for matching blood glucose levels and blood pressure with the liraglutide group. The control groups of SDT fatty (n = 7) and non-diabetic Sprague-Dawley rats (n = 7) were injected only with a vehicle.

RESULTS

The control group of SDT fatty rats exhibited hyperglycemia, obesity, hypertension, hyperlipidemia, glomerular sclerosis, and tubulointerstitial injury with high urinary albumin and L-FABP levels. Liraglutide treatment reduced body weight, food intake, blood glucose and blood pressure levels, as well as ameliorated renal pathologic findings with lower urinary albumin and L-FABP levels. Liraglutide increased expressions of phosphorylated (p)-eNOS and p-AMPK in glomeruli, downregulated renal expression of p-mTOR, and increased renal expressions of LC3B-II, suggesting activation of autophagy. However, these effects were not caused by the treatments with insulin and hydralazine, despite comparable levels of hyperglycemia and hypertension to those achieved with liraglutide treatment.

CONCLUSIONS

Liraglutide may exert a renoprotective effect via prevention of glomerular endothelial abnormality and preservation of autophagy in early-phase DKD, independent of blood glucose, and blood pressure levels.

Activation of G protein-coupled estrogen receptor 1 ameliorates proximal tubular injury and proteinuria in Dahl salt-sensitive female rats

Recent evidence indicates a crucial role for G protein-coupled estrogen receptor 1 (GPER1) in the maintenance of cardiovascular and kidney health in females. The current study tested whether GPER1 activation ameliorates hypertension and kidney damage in female Dahl salt-sensitive (SS) rats fed a high-salt (HS) diet. Adult female rats were implanted with telemetry transmitters for monitoring blood pressure and osmotic minipumps releasing G1 (selective GPER1 agonist, 400 μg/kg/day ip) or vehicle. Two weeks after pump implantation, rats were shifted from a normal-salt (NS) diet (0.4% NaCl) to a matched HS diet (4.0% NaCl) for 2 wk. Twenty-four hour urine samples were collected during both diet periods and urinary markers of kidney injury were assessed. Histological assessment of kidney injury was conducted after the 2-wk HS diet period. Compared with values during the NS diet, 24-h mean arterial pressure markedly increased in response to HS, reaching similar values in vehicle-treated and G1-treated rats. HS also significantly increased urinary excretion of protein, albumin, nephrin (podocyte damage marker), and KIM-1 (proximal tubule injury marker) in vehicle-treated rats. Importantly, G1 treatment prevented the HS-induced proteinuria, albuminuria, and increase in KIM-1 excretion but not nephrinuria. Histological analysis revealed that HS-induced glomerular damage did not differ between groups. However, G1 treatment preserved proximal tubule brush-border integrity in HS-fed rats. Collectively, our data suggest that GPER1 activation protects against HS-induced proteinuria and albuminuria in female Dahl SS rats by preserving proximal tubule brush-border integrity in a blood pressure-independent manner.

Effect of dapagliflozin as an adjunct to insulin over 52 weeks in individuals with type 1 diabetes: post-hoc renal analysis of the DEPICT randomised controlled trials

BACKGROUND

The DEPICT-1 and DEPICT-2 studies showed that dapagliflozin as an adjunct to insulin in individuals with inadequately controlled type 1 diabetes improved glycaemic control and bodyweight, without increase in risk of hypoglycaemia. We aimed to determine the effect of dapagliflozin on urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) using pooled data from the DEPICT studies.

METHODS

In this post-hoc analysis, we used data pooled from both DEPICT studies (DEPICT-1 ran from Nov 11, 2014, to Aug 25, 2017; DEPICT-2 ran from July 8, 2015, to April 18, 2018), in which participants were aged 18-75 years, with inadequately controlled type 1 diabetes and with a baseline UACR of at least 30 mg/g. In the DEPICT studies, participants were randomly assigned (1:1:1) to receive dapagliflozin (5 mg or 10 mg) or placebo all plus insulin, for 24 weeks, with a 28-week long-term extension (ie, 52 weeks in total). In this post-hoc analysis, we assessed the percentage change from baseline in UACR and in eGFR, up to 52 weeks. UACR, eGFR, and safety were assessed in all eligible participants who had received at least one dose of study drug. HbA_1c, bodyweight, and systolic blood pressure were assessed in all participants who received at least one dose of study drug during the first 24-week period, and who had a baseline and any post-baseline assessment for that parameter. The DEPICT trials were registered with ClinicalTrials.gov, NCT02268214 (DEPICT-1), NCT02460978 (DEPICT-2), and are now complete.

RESULTS

251 participants with albuminuria at baseline were included in this post-hoc analysis; of whom 80 (32%) had been randomly assigned to dapagliflozin 5 mg, 84 (33%) to dapagliflozin 10 mg, and 87 (35%) to placebo. Compared with placebo, treatment with both dapagliflozin doses improved UACR over 52 weeks. At week 52, mean difference in change from baseline versus placebo in UACR was -13·3% (95% CI -37·2 to 19·8) for dapagliflozin 5 mg and -31·1% (-49·9 to -5·2) for dapagliflozin 10 mg. No notable change from baseline was seen in eGFR, with a mean difference in change from baseline versus placebo of 3·27 mL/min per 1·73 m² (95% CI -0·92 to 7·45) for dapagliflozin 5 mg and 2·12 mL/min per 1·73 m² (-2·03 to 6·27) for dapagliflozin 10 mg. Similar proportions of participants in each treatment group had adverse events and serious adverse events, including hypoglycaemia and diabetic ketoacidosis; no new safety signals were identified in this population.

INTERPRETATION

Treatment with dapagliflozin resulted in UACR reduction, which might provide renoprotective benefits in individuals with type 1 diabetes and albuminuria. Dedicated prospective studies are needed to confirm these findings as prespecified endpoints.

FUNDING

AstraZeneca.

Effect of low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate higher than 60 mL/min/1.73 m2 with or without albuminuria

BACKGROUND

We aimed to investigate the effect of a low-protein intake on all-cause mortality in subjects with an estimated glomerular filtration rate (eGFR) ≧60 mL/min/1.73 m² with or without albuminuria using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

We analysed participants in the NHANES from 2003 to 2010. We excluded participants with an eGFR less than 60 mL/min/1.73 m² from the analyses. Low-protein intake was defined as a protein intake of less than 0.8 g/kg/day. The Healthy Eating Index 2010 was used to assess diet quality. The vital status of all participants in the NHANES was determined by linking to the National Death Index through the end of 2011. The hazard ratios (HRs) for the association of low-protein intake and mortality were determined using weighted Cox proportional hazards regression models.

RESULTS

A total of 7730 participants were included in the analyses. After a median follow up of 4.7 years, 462 participants died. A low-protein intake was associated with a higher risk of mortality (HRs 1.394, 95% CI 1.121-1.734, P = .004) with adjustment for diet quality and relevant risk factors. The higher risk of mortality associated with a low-protein intake was consistent in subjects with or without albuminuria (P interaction .280).

CONCLUSION

A protein intake of less than 0.8 g/kg/day was associated with a higher risk of mortality in subjects with an eGFR ≧60 mL/min/1.73 m² , irrespective of whether they had albuminuria.

Increasing potassium intake to prevent kidney damage: a new population strategy?

Reducing dietary sodium consumption and increasing potassium intake are effective approaches in reducing the prevalence of cardiovascular diseases. Whether this is also true for chronic kidney disease (CKD) is still debated. Elfassy et al. have examined associations between urinary sodium and potassium excretion and the incidence of CKD in young, 30-year-old subjects followed for 20 years. Although they failed to find an association between sodium intake and CKD incidence, there was an inverse association between high potassium intake and the development of albuminuria.

Enhancing kidney DDAH-1 expression by adenovirus delivery reduces ADMA and ameliorates diabetic nephropathy

Endothelial dysfunction, characterized by reduced bioavailability of nitric oxide and increased oxidative stress, is a hallmark characteristic in diabetes and diabetic nephropathy (DN). High levels of asymmetric dimethylarginine (ADMA) are observed in several diseases including DN and are a strong prognostic marker for cardiovascular events in patients with diabetes and end-stage renal disease. ADMA, an endogenous endothelial nitric oxide synthase (NOS3) inhibitor, is selectively metabolized by dimethylarginine dimethylaminohydrolase (DDAH). Low DDAH levels have been associated with cardiac and renal dysfunction, but its effects on DN are unknown. We hypothesized that enhanced renal DDAH-1 expression would improve DN by reducing ADMA and restoring NOS3 levels. DBA/2J mice injected with multiple low doses of vehicle or streptozotocin were subsequently injected intrarenally with adenovirus expressing DDAH-1 (Ad-h-DDAH-1) or vector control [Ad-green fluorescent protein (GFP)], and mice were followed for 6 wk. Diabetes was associated with increased kidney ADMA and reduced kidney DDAH activity and DDAH-1 expression but had no effect on kidney DDAH-2 expression. Ad-GFP-treated diabetic mice showed significant increases in albuminuria, histological changes, glomerular macrophage recruitment, inflammatory cytokine and fibrotic markers, kidney ADMA levels, and urinary thiobarbituric acid reactive substances excretion as an indicator of oxidative stress, along with a significant reduction in kidney DDAH activity and kidney NOS3 mRNA compared with normal mice. In contrast, Ad-h-DDAH-1 treatment of diabetic mice reversed these effects. These data indicate, for the first time, that DDAH-1 mediates renal tissue protection in DN via the ADMA-NOS3-interaction. Enhanced renal DDAH-1 activity could be a novel therapeutic tool for treating patients with diabetes.

Early Diabetic Nephropathy and Retinopathy in Patients with Type 1 Diabetes Mellitus Attending Sudan Childhood Diabetes Centre

OBJECTIVE

Data on microvascular complications in children and adolescents with type 1 diabetes mellitus (T1DM) in Sudan are scarce. This study was aimed at determining the prevalence of diabetic nephropathy (DN) and retinopathy (DR) and their relationship to certain risk factors in children with T1DM attending the Sudan Childhood Diabetes Centre. Design and Methods. A clinic-based cross-sectional study of 100 patients with T1DM aged 10-18 years. Patients with disease duration exceeding 5 years if the onset of diabetes was prepubertal and 2 years if it was postpubertal were included. Relevant sociodemographic, clinical, and biochemical information was obtained. Blood pressure was measured. The patients were screened for DN and DR using urinary microalbumin estimation and fundus photography, respectively.

RESULTS

The frequency of microalbuminuria and diabetic retinopathy was 36% and 33%, respectively. Eleven percent had both retinopathy and microalbuminuria. Seven percent of the patients were found to be hypertensive. Patients with diabetic retinopathy had significantly higher HbA1c levels (p = 0.009) and longer diabetes duration (p = 0.02) than patients without retinopathy. Logistic regression showed that high HbA1c (odds ratio (OR) 0.83, confidence interval (CI) 0.68-1.00, p = 0.04), but not age, duration, ethnic group, BMI, blood pressure, and presence of nephropathy, was an independent risk factor for retinopathy. Likewise, high blood pressure (OR 6.89, CI 1.17-40.52, p = 0.03), but not age, duration, ethnic group, BMI, HbA1c, and presence of retinopathy, was a predictor for nephropathy.

CONCLUSION

High prevalence of incipient DN and early stages of DR were observed in this study. Longer diabetes duration and higher HbA1c were associated with the presence of diabetic retinopathy. High blood pressure was a risk factor for DN. So regular screening for these complications and optimization of glycemic control are needed.

Dulaglutide and renal outcomes in type 2 diabetes: an exploratory analysis of the REWIND randomised, placebo-controlled trial

BACKGROUND

Two glucagon-like peptide-1 (GLP-1) receptor agonists reduced renal outcomes in people with type 2 diabetes at risk for cardiovascular disease. We assessed the long-term effect of the GLP-1 receptor agonist dulaglutide on renal outcomes in an exploratory analysis of the REWIND trial of the effect of dulaglutide on cardiovascular disease.

METHODS

REWIND was a multicentre, randomised, double-blind, placebo-controlled trial at 371 sites in 24 countries. Men and women aged at least 50 years with type 2 diabetes who had either a previous cardiovascular event or cardiovascular risk factors were randomly assigned (1:1) to either weekly subcutaneous injection of dulaglutide (1·5 mg) or placebo and followed up at least every 6 months for outcomes. Urinary albumin-to-creatinine ratios (UACRs) and estimated glomerular filtration rates (eGFRs) were estimated from urine and serum values measured in local laboratories every 12 months. The primary outcome (first occurrence of the composite endpoint of non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular causes), secondary outcomes (including a composite microvascular outcome), and safety outcomes of this trial have been reported elsewhere. In this exploratory analysis, we investigate the renal component of the composite microvascular outcome, defined as the first occurrence of new macroalbuminuria (UACR >33·9 mg/mmol), a sustained decline in eGFR of 30% or more from baseline, or chronic renal replacement therapy. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01394952.

FINDINGS

Between Aug 18, 2011, and Aug 14, 2013, 9901 participants were enrolled and randomly assigned to receive dulaglutide (n=4949) or placebo (n=4952). At baseline, 791 (7·9%) had macroalbuminuria and mean eGFR was 76·9 mL/min per 1·73 m² (SD 22·7). During a median follow-up of 5·4 years (IQR 5·1-5·9) comprising 51 820 person-years, the renal outcome developed in 848 (17·1%) participants at an incidence rate of 3·5 per 100 person-years in the dulaglutide group and in 970 (19·6%) participants at an incidence rate of 4·1 per 100 person-years in the placebo group (hazard ratio [HR] 0·85, 95% CI 0·77-0·93; p=0·0004). The clearest effect was for new macroalbuminuria (HR 0·77, 95% CI 0·68-0·87; p<0·0001), with HRs of 0·89 (0·78-1·01; p=0·066) for sustained decline in eGFR of 30% or more and 0·75 (0·39-1·44; p=0·39) for chronic renal replacement therapy.

INTERPRETATION

Long-term use of dulaglutide was associated with reduced composite renal outcomes in people with type 2 diabetes.

FUNDING

Eli Lilly and Company.

Reduction in albuminuria with dapagliflozin cannot be predicted by baseline clinical characteristics or changes in most other risk markers

The sodium glucose co-transporter-2 inhibitor dapagliflozin has been shown to decrease urinary albumin-to-creatinine ratio (UACR). This effect, however, varies among individual patients. In this study, we assessed the baseline characteristics and concurrent changes in other cardiovascular risk markers that might be associated with UACR response to dapagliflozin. A pooled analysis of 11 phase 3 randomized, controlled clinical trials was performed. UACR change from baseline after 24 weeks treatment with dapagliflozin 10 mg/d in 531 patients with type 2 diabetes and UACR ≥30 mg/g at baseline was determined. UACR response was defined as >30% reduction from baseline at 24 weeks, whereas UACR non-response was defined as ≤30% reduction at 24 weeks. A total of 288 (54%) patients were classified as responders and 243 (46%) as non-responders. At 24 weeks, the UACR-adjusted mean change from baseline was -71.2% and 25.9% in responders and non-responders, respectively. Baseline characteristics were similar between both groups. Changes in HbA1c and body weight were comparable across groups. Responders showed a numerically larger reduction in estimated glomerular filtration rate and systolic blood pressure versus non-responders. UACR reduction to dapagliflozin is an individual characteristic that cannot be predicted by baseline clinical features or changes in metabolic variables. Whether UACR response would improve long-term renal and cardiovascular outcomes remains to be determined.

Effects of Dipeptidyl Peptidase-4 Inhibitors on Renal Outcomes in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

BACKGROUND

To investigate the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on renal outcomes in patients with type 2 diabetes.

METHODS

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched to identify randomized controlled trials (RCTs) of DPP-4 inhibitors from inception to September 2017. We selected eligible RCTs comparing DPP-4 inhibitors with placebo or other antidiabetic agents and reporting at least one renal outcome. A meta-analysis was conducted to calculate standardized mean differences, weighted mean differences (WMDs), relative risks (RRs), and 95% confidence intervals (CIs) for each renal outcome.

RESULTS

We included 23 RCTs with 19 publications involving 41,359 patients. Overall changes in urine albumin-to-creatinine ratio were comparable between DPP-4 inhibitors and controls (P=0.150). However, DPP-4 inhibitors were associated with significantly lower risk of incident microalbuminuria (RR, 0.89; 95% CI, 0.80 to 0.98; P=0.022) and macroalbuminuria (RR, 0.77; 95% CI, 0.61 to 0.97; P=0.027), as well as higher rates of regression of albuminuria (RR, 1.22; 95% CI, 1.10 to 1.35; P<0.001) compared with controls. Although DPP-4 inhibitors were associated with small but significantly lower estimated glomerular filtration rate (WMD, -1.11 mL/min/1.73 m²; 95% CI, -1.78 to -0.44; P=0.001), there was no difference in the risk of end-stage renal disease between two groups (RR, 0.93; 95% CI, 0.76 to 1.14; P=0.475).

CONCLUSION

DPP-4 inhibitors had beneficial renal effects mainly by reducing the risk of development or progression of albuminuria compared with placebo or other antidiabetic agents.

Paucity of high-quality studies reporting on salt and health outcomes from the science of salt: A regularly updated systematic review of salt and health outcomes (April 2017 to March 2018)

The purpose of this review is to identify, summarize, and critically appraise studies on dietary salt and health outcomes that were published from April 2017 to March 2018. The search strategy was adapted from a previous systematic review on dietary salt and health. Identified studies were screened based on a priori defined criteria to identify publications eligible for detailed critical appraisals. Overall, 6747 citations were identified by the search strategy, and 42 health outcome studies were identified. Three of the 42 studies met the criteria for methodological quality and health outcomes and underwent detailed critical appraisals and commentary. In addition, a systematic review and meta-analysis was critically appraised, although it did not strictly meet our methodological criteria. All four of the studies critically appraised found that sodium reduction improved blood pressure, especially in individuals with hypertension. In addition, sodium reduction reduced albuminuria in patients with stage 1-3 chronic kidney disease. Examination of the time course of blood pressure responses to sodium reduction revealed lowering sodium in the context of an average American diet may not produce maximal blood pressure reductions within a 4-week intervention period. This review provides further evidence of the benefit of sodium reduction for blood pressure lowering and gives insights into the subgroups of the population that may derive the greatest benefit from sodium reduction and the time course required to see benefit. Only three high-quality studies were identified during this 12-month review period, highlighting the critical need for more well-conducted rigorous studies in this area.

Efficacy of a novel inhibitor of vascular adhesion protein-1 in reducing albuminuria in patients with diabetic kidney disease (ALBUM): a randomised, placebo-controlled, phase 2 trial

BACKGROUND

Many patients with diabetic kidney disease have residual albuminuria and are at risk of disease progression. The ALBUM trial investigated the efficacy of a novel, orally active inhibitor of vascular adhesion protein-1, ASP8232, compared with placebo for reducing albuminuria in individuals with type 2 diabetes and chronic kidney disease.

METHODS

In this randomised, double-blind, placebo-controlled phase 2 trial, we randomly assigned individuals (aged 18-85 years) from 64 clinical sites in nine European countries to receive ASP8232 40 mg or placebo orally once daily for 12 weeks using a web-based randomisation schedule (block size 4), stratified by country. Eligible patients had a urinary albumin-to-creatinine ratio (UACR) of 200-3000 mg/g, an estimated glomerular filtration rate of at least 25 mL/min per 1·73 m² but lower than 75 mL/min per 1·73 m², HbA_1c less than 11·0% (97 mmol/mol), and stable treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and antidiabetic medication for 3 months or more. The primary endpoint was mean change from baseline to week 12 in log-transformed first morning void UACR, which was assessed in all patients who received at least one dose of study drug and had at least one post-baseline UACR measurement (full analysis set). Safety was assessed in all patients who received at least one dose of study drug. Participants and investigators were masked to treatment allocation. This trial is registered with ClinicalTrials.gov, number NCT02358096.

FINDINGS

125 participants were randomly assigned to receive ASP8232 (n=64) or placebo (n=61), of whom 120 (60 in each group) were included in the full analysis set; all participants were assessed for safety endpoints. At 12 weeks, UACR decreased by 17·7% (95% CI 5·0 to 28·6) in the ASP8232 group and increased by 2·3% (-11·4 to 18·1) in the placebo group; the placebo-adjusted difference between groups was -19·5% (95% CI -34·0 to -1·8; p=0·033). 39 (61%) patients in the ASP8232 group and 34 (56%) patients in the placebo group had a treatment-emergent adverse event, of which 16 in the ASP8232 group and four in the placebo group were drug-related. The most frequently reported adverse events that were possibly drug-related in the ASP8232 group were renal impairment (five patients) and decreased eGFR (three patients); in the placebo group, no single drug-related treatment-emergent adverse event was reported by more than one participant.

INTERPRETATION

ASP8232 is effective in reducing albuminuria in patients with diabetic kidney disease and is safe and well tolerated. These findings warrant further research to ascertain the effect of ASP8232 on delaying progression of diabetic kidney disease.

FUNDING

Astellas.

Comparative efficacy of individual renin-angiotensin system inhibitors on major renal outcomes in diabetic kidney disease: a network meta-analysis

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are two drug classes with well-documented renal protective effects. However, whether there is any difference among individual drugs remains unknown. In this study, we aimed to compare the efficacy of individual ACEIs/ARBs on major renal outcomes in adults with diabetic kidney disease (DKD).

METHODS

We conducted a Bayesian-framework network meta-analysis with a random effects model. We searched PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for clinical trials of ACEIs or ARBs as monotherapy compared with other conventional antihypertensive drugs or placebo. Primary outcomes were end-stage renal disease (ESRD) and albuminuria/proteinuria (including change in albuminuria/proteinuria, progression to macroalbuminuria and remission to normoalbuminuria). Secondary outcome was doubling of serum creatinine levels. We also assessed for hyperkalemia, cough and angioedema/edema. International prospective register of systematic reviews (PROSPERO) registration CRD42016036997.

RESULTS

A total of 100 studies with data for 22 365 DKD patients, the majority of whom had type 2 diabetes, were included. Individual ACEIs and ARBs at goal doses showed no significant differences in ESRD and doubling of serum creatinine levels. They also shared similar effects on albuminuria/proteinuria reduction and progression or remission of albuminuria. When combining three outcomes of albuminuria/proteinuria as a single endpoint, most ACEIs/ARBs consistently showed favorable antiproteinuric effect, with little difference in the possibility of being the superior treatment for improving albuminuria/proteinuria. Primary outcomes did not change substantially in meta-regressions and sensitivity analyses. Findings were limited by lack of dose equivalence and paucity of data for some outcomes.

CONCLUSIONS

Based on the available evidence, individual ACEIs and ARBs at goal doses appeared to have no or little differences in their effect on major renal outcomes.

IMPROVEMENT OF TREATMENT IN PERSONS WITH ARTERIAL HYPERTENSION AND TYPE 2 DIABETES MELLITUS

The aim of study was the optimization of treatment in patients with arterial hypertension and coexistent type 2 diabetes mellitus. The study involved 96 persons with arterial hypertension and type 2 diabetes mellitus (2 of them were excluded). Patients with arterial hypertension and type 2 diabetes mellitus (n=94) were divided in two subgroups: persons from the first (n=54) were treated by telmisartan 40-80 mg/day; second (n=40) - by lisinopril 10-20 mg/day. People from the first subgroup (n=54) were divided in Іa (n=25) and Іb (n=29) according to the level of endothelin-1. Persons from the Іa subgroup with less than 10 pg/ml levels of endothelin were treated by telmisartan 40 mg/day. People from the Іb subgroup with more than 10 pg/ml levels of endothelin were treated by telmisartan 80 mg/day. Patients were observed by echocardiography, albumin excretion rate in six months and by glycated hemoglobin in 3 months. Telmisartan is not worse than lisinopril according to protection of heart and kidney. Under the influence of treatment with telmisartan at a dose of 40 mg/day in subjects with arterial hypertension and type 2 diabetes mellitus and less than 10 pg/ml level of endothelin-1, the values of albumin excretion rate decreased by 9,7% (p=0,0328), and left ventricular mass index - by 6,7% (p=0,0007). In coexistent patients with greater than 10 pg/ml level of endothelin-1 and 80 mg/day dose of telmisartan, the level of albumin excretion rate was reduced by 4,9% (p=0,0435), and left ventricular mass index - by 3,1% (p<0,0001). If the level of this indicator is less than 10 pg/ml, the dose of telmisartan is 40 mg/day, if the level of endothelin-1 is more than 10 pg/ml, the dose of telmisartan is 80 mg/day.

Light wine consumption is associated with a lower odd for cardiovascular disease in chronic kidney disease

AIMS

To examine the association between wine consumption and the prevalence of chronic kidney disease (CKD) and cardiovascular disease (CVD).

DATA SYNTHESIS

We performed a cross-sectional logistic regression analysis of National Health and Nutrition Examination Survey (NHANES) in participants 21 years of age or older from 2003 to 2006 in a large representative study of the U.S.

POPULATION

Wine consumption was categorized as none (0 glass per day), light (<1 glass per day), or moderate (≥1 glasses per day). Prevalent CKD was defined as a urine albumin/creatinine ratio (UACR) ≥30 mg/g or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². CVD was defined as history of CVD including angina, myocardial infarction, or stroke. Only 27 (0.5%) individuals reported moderate wine consumption, whereas 57.5% and 42% reported abstinence and light wine consumption, respectively. Light wine consumption was associated with a lower prevalence of CKD as opposed to abstinence in unadjusted analysis. After adjusting for demographics and CVD risk factors light wine consumption was associated with lower prevalence of CKD defined as UACR ≥30 mg/g but not with low eGFR. Furthermore, light wine consumption was associated with significantly lower rates of CVD in the general population and in subjects with CKD. The adjusted odd of CVD for those with light wine consumption was 0.72 (CI 0.52-0.99, p = 0.046) for the subjects with CKD.

CONCLUSION

These data suggest that light wine consumption (compared to abstinence) is associated with lower prevalence of CKD and a lower odd of CVD in those with CKD in the U.S.

Lixisenatide and renal outcomes in patients with type 2 diabetes and acute coronary syndrome: an exploratory analysis of the ELIXA randomised, placebo-controlled trial

BACKGROUND

The results of the ELIXA trial demonstrated the cardiovascular safety of lixisenatide, a short-acting glucagon-like peptide-1 receptor agonist, in patients with type 2 diabetes and acute coronary syndrome. In this exploratory analysis of ELIXA, we investigate the effect of lixisenatide on renal outcomes.

METHODS

ELIXA was a randomised, double-blind, placebo-controlled trial, done at 828 sites in 49 countries. Patients with type 2 diabetes and a recent coronary artery event were randomly assigned (1:1) to a daily subcutaneous injection of lixisenatide (10-20 μg) or volume-matched placebo, in addition to usual care, until at least 844 patients had an adjudicated major adverse cardiovascular event included in the primary outcome. Patients, study staff, and individuals involved in analysis of trial data were masked to treatment assignment. The primary and secondary endpoints of this trial have been reported previously. Here, in an exploratory analysis of ELIXA, we investigated percentage change in urinary albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR) according to prespecified albuminuria status at baseline (normoalbuminuria [UACR <30 mg/g]; microalbuminuria [≥30 to ≤300 mg/g]; and macroalbuminuria [>300 mg/g]) using a mixed-effect model with repeated measures. Time to new-onset macroalbuminuria and doubling of serum creatinine were also assessed with Cox proportional hazards models. The ELIXA trial is registered with ClinicalTrials.gov, number NCT01147250, and is completed.

FINDINGS

Of 6068 patients randomly allocated between July 9, 2010, and Aug 2, 2013, baseline UACR data were available for 5978 (99%). Median follow-up time was 108 weeks. 4441 (74%; 2191 assigned to placebo and 2250 assigned to lixisenatide) had normoalbuminuria, 1148 (19%; 596 assigned to placebo and 552 assigned to lixisenatide) had microalbuminuria, and 389 (7%; 207 assigned to placebo and 182 assigned to lixisenatide) had macroalbuminuria. After 108 weeks, the placebo-adjusted least-squares mean percentage change in UACR from baseline with lixisenatide was -1·69% (95% CI -11·69 to 8·30; p=0·7398) in patients with normoalbuminuria, -21·10% (-42·25 to 0·04; p=0·0502) in patients with microalbuminuria, and -39·18% (-68·53 to -9·84; p=0·0070) in patients with macroalbuminuria. Lixisenatide was associated with a reduced risk of new-onset macroalbuminuria compared with placebo when adjusted for baseline HbA_1c (hazard ratio [HR] 0·808 [95% CI 0·660 to 0·991; p=0·0404]) or baseline and on-trial HbA_1c (HR 0·815 [0·665 to 0·999; p=0·0491]); point estimates were similar when adjusted for other traditional renal risk factors. At week 108, the largest eGFR decline from baseline was observed in the macroalbuminuric group, but no significant differences were observed between the two treatment groups. No significant differences in eGFR decline were identified between treatment groups in any UACR subgroup. In the trial safety population, doubling of serum creatinine occurred in 35 (1%) of 3032 patients in the placebo group and 41 (1%) of 3031 patients in the lixisenatide group (HR 1·163, 95% CI 0·741-1·825; p=0·5127). As previously reported in the ELIXA trial, the proportion of patients with renal adverse events was low (48 [1·6%] of 3032 patients in the placebo group vs 48 [1·6%] of 3031 patients in the lixisenatide group) and did not significantly differ between treatment groups.

INTERPRETATION

Lixisenatide reduces progression of UACR in macroalbuminuric patients, and is associated with a lower risk of new-onset macroalbuminuria after adjustment for baseline and on-trial HbA_1c and other traditional renal risk factors.

FUNDING

Sanofi.

Inhibition of Epidermal Growth Factor Receptor Activation Is Associated With Improved Diabetic Nephropathy and Insulin Resistance in Type 2 Diabetes

Previous studies by us and others have indicated that renal epidermal growth factor receptors (EGFR) are activated in models of diabetic nephropathy (DN) and that inhibition of EGFR activity protects against progressive DN in type 1 diabetes. In this study we examined whether inhibition of EGFR activation would affect the development of DN in a mouse model of accelerated type 2 diabetes (BKS db/db with endothelial nitric oxide knockout [eNOS^-/-db/db]). eNOS^-/-db/db mice received vehicle or erlotinib, an inhibitor of EGFR tyrosine kinase activity, beginning at 8 weeks of age and were sacrificed at 20 weeks of age. In addition, genetic models inhibiting EGFR activity (waved 2) and transforming growth factor-α (waved 1) were studied in this model of DN in type 2 diabetes. Compared with vehicle-treated mice, erlotinib-treated animals had less albuminuria and glomerulosclerosis, less podocyte loss, and smaller amounts of renal profibrotic and fibrotic components. Erlotinib treatment decreased renal oxidative stress, macrophage and T-lymphocyte infiltration, and the production of proinflammatory cytokines. Erlotinib treatment also preserved pancreas function, and these mice had higher blood insulin levels at 20 weeks, decreased basal blood glucose levels, increased glucose tolerance and insulin sensitivity, and increased blood levels of adiponectin compared with vehicle-treated mice. Similar to the aforementioned results, both waved 1 and waved 2 diabetic mice also had attenuated DN, preserved pancreas function, and decreased basal blood glucose levels. In this mouse model of accelerated DN, inhibition of EGFR signaling led to increased longevity.

Determining the optimal dose of atrasentan by evaluating the exposure-response relationships of albuminuria and bodyweight

This study aimed to identify the optimal dose of the endothelin-1 receptor antagonist atrasentan with maximal albuminuria reduction and minimal signs of sodium retention, as manifested by increase in bodyweight. Data from the RADAR-JAPAN studies were used, evaluating the effect of 0.75 or 1.25 mg/d of atrasentan in 161 patients with type 2 diabetes and kidney disease. Individual pharmacokinetic parameters were estimated using a population pharmacokinetic approach. Subsequently, changes in the urinary albumin-to-creatinine ratio (UACR) and bodyweight from baseline after 2 weeks' exposure were modelled as a function of the pharmacokinetic parameters. The 0.75 and 1.25 mg doses showed a mean UACR reduction of 34.0% and 40.1%, whereas mean bodyweight increased by 0.9 and 1.1 kg, respectively. A large variation between individuals was observed in the UACR and bodyweight responses. Individual pharmacokinetic parameters correlated significantly with both individual UACR and bodyweight responses (P < .01). The individual response curves for UACR and bodyweight crossed at approximately the mean trough concentration of 0.75 mg atrasentan, indicating that 0.75 mg/d of atrasentan is the optimal dose for kidney protection with maximal efficacy (albuminuria reduction) and safety (minimal sodium retention).

Effects of the SGLT-2 inhibitor dapagliflozin on glomerular and tubular injury markers

The mechanisms by which SGLT-2 inhibitors lower albuminuria are incompletely understood. We assessed in a post-hoc analysis of a cross-over trial the effects of the SGLT2 inhibitor dapagliflozin on glomerular markers (IgG to IgG4 and IgG to albumin), tubular markers (urinary KIM-1, NGAL and LFABP) and inflammatory markers (urinary MCP-1 and IL-6) to provide more insight into kidney protective effects. Dapagliflozin decreased albuminuria by 43.9% (95% CI, 30.3%-54.8%) and eGFR by 5.1 (2.0-8.1) mL/min/1.73m² compared to placebo. Dapagliflozin did not change glomerular charge or size selectivity index compared to placebo. Dapagliflozin decreased urinary KIM-1 excretion by 22.6% (0.3%-39.8%; P = .05) and IL-6 excretion by 23.5% (1.4%-40.6%; P = .04) compared to placebo, whereas no changes in NGAL, LFABP and MCP-1 were observed. During dapagliflozin treatment, changes in albuminuria correlated with changes in eGFR (r = 0.36; P = .05) and KIM-1 (r = 0.39; P = .05). In conclusion, the albuminuria-lowering effect of 6 weeks of dapagliflozin therapy may be the result of decreased intraglomerular pressure or reduced tubular cell injury.

Individual variability in response to renin angiotensin aldosterone system inhibition predicts cardiovascular outcome in patients with type 2 diabetes: A primary care cohort study

AIMS

To assess variability in systolic blood pressure (SBP) and albuminuria (urinary albumin creatinine ratio [UACR]) responses in patients with type 2 diabetes mellitus initiating renin angiotensin aldosterone system (RAAS) inhibition, and to assess the association of response variability with cardiovascular outcomes.

MATERIAL AND METHODS

We performed an observational cohort study in patients with type 2 diabetes who started RAAS inhibition between 2007 and 2013 (n = 1600). Patients were identified from general practices in the Netherlands. Individual response in SBP and UACR was assessed during 15 months' follow-up. Patients were categorized as: good responders (∆SBP <0 mm Hg and ∆UACR <0%); intermediate responders (∆SBP <0 mm Hg and ∆UACR >0% or ∆SBP >0 mm Hg and ∆UACR <0%); or poor responders (∆SBP >0 mm Hg and ∆UACR >0%). Multivariable Cox regression was performed to test the association between initial RAAS inhibition response and subsequent cardiovascular outcomes.

RESULTS

After starting RAAS inhibition, the mean SBP change was -13.2 mm Hg and the median UACR was -36.6%, with large between-individual variability, both in SBP [5th to 95th percentile: 48.5-20] and UACR [5th to 95th percentile: -87.6 to 171.4]. In all, 812 patients (51%) were good responders, 353 (22%) had a good SBP but poor UACR response, 268 (17%) had a good UACR but poor SBP response, and 167 patients (10%) were poor responders. Good responders had a lower risk of cardiovascular events than poor responders (hazard ratio 0.51, 95% confidence interval 0.30-0.86; P = .012).

CONCLUSIONS

SBP and UACR response after RAAS inhibition initiation varied between and within individual patients with type 2 diabetes treated in primary care. Poor responders had the highest risk of cardiovascular events, therefore, more efforts are needed to develop personalized treatment plans for these patients.

Increased podocyte Sirtuin-1 function attenuates diabetic kidney injury

Podocyte injury and loss contribute to the progression of glomerular diseases, including diabetic kidney disease. We previously found that the glomerular expression of Sirtuin-1 (SIRT1) is reduced in human diabetic glomeruli and that the podocyte-specific loss of SIRT1 aggravated albuminuria and worsened kidney disease progression in diabetic mice. SIRT1 encodes an NAD-dependent deacetylase that modifies the activity of key transcriptional regulators affected in diabetic kidneys, including NF-κB, STAT3, p53, FOXO4, and PGC1-α. However, whether the increased glomerular SIRT1 activity is sufficient to ameliorate the pathogenesis of diabetic kidney disease has not been explored. We addressed this by inducible podocyte-specific SIRT1 overexpression in diabetic OVE26 mice. The induction of SIRT1 overexpression in podocytes for six weeks in OVE26 mice with established albuminuria attenuated the progression of diabetic glomerulopathy. To further validate the therapeutic potential of increased SIRT1 activity against diabetic kidney disease, we developed a new, potent and selective SIRT1 agonist, BF175. In cultured podocytes BF175 increased SIRT1-mediated activation of PGC1-α and protected against high glucose-mediated mitochondrial injury. In vivo, administration of BF175 for six weeks in OVE26 mice resulted in a marked reduction in albuminuria and in glomerular injury in a manner similar to podocyte-specific SIRT1 overexpression. Both podocyte-specific SIRT1 overexpression and BT175 treatment attenuated diabetes-induced podocyte loss and reduced oxidative stress in glomeruli of OVE26 mice. Thus, increased SIRT1 activity protects against diabetes-induced podocyte injury and effectively mitigates the progression of diabetic kidney disease.

Fresh fruit consumption and risk of incident albuminuria among rural Chinese adults: A village-based prospective cohort study

Background

Recent studies showed that increased fresh fruit consumption is significantly associated with lower risks of diabetes, hypertension, and cardiovascular disease (CVD); other studies suggested that albuminuria is associated with diabetes, hypertension, and CVD. Therefore, we hypothesized that lower fresh fruit consumption is associated with higher risk of incident albuminuria among Chinese adults in rural areas, where fresh fruit consumption level is very low and prevalence of albuminuria is high.

Methods

We tested the hypothesis in a village-based cohort study of 3574 participants aged ≥ 30 years from the Handan Eye Study conducted from 2006 to 2013. Albuminuria was defined as urinary albumin-to-creatinine ratio ≥ 30 mg/g.

Results

Overall, 35.4% of the participants never or rarely consumed fresh fruits, and 33.9, 21.6, and 9.1% consumed fresh fruits 1–3 times/month, 1–2 times/week, and ≥ 3 times/week, respectively. During a median follow-up period of 5.6 years, albuminuria developed in 17.6% (n = 629) of the participants. Compared with participants who consumed fresh fruits ≥ 3 times/week, the multivariable adjustment odds ratios (ORs) for incident albuminuria associated with fruit consumption 1–2 times/week, 1–3 times/month, and no or rare consumption were 1.58 (95% confidence intervals (CI), 1.05–2.40), 1.74 (95% CI, 1.17–2.58), and 1.78 (95% CI, 1.20–2.64), respectively. After excluding participants with diabetes, the association remained significant.

Conclusions

Lower fresh fruit consumption was significantly associated with higher risk of incident albuminuria, and fresh fruit consumption frequency could be an essential intervention target to prevent albuminuria in rural China.

The MARLINA-T2D trial: putting the results into clinical perspective

Chronic kidney disease (CKD) and type 2 diabetes mellitus (T2D) frequently coexist and are associated with poor clinical outcomes. Dipeptidyl peptidase-4 (DPP-4) inhibitors can be used for patients with T2D and CKD, and preclinical evidence suggests these agents may slow the progression of kidney disease in T2D. Although clinical evidence of the renal effects of DPP-4 inhibitors is limited, the recent publication of the MARLINA-T2D study provided important new data. In MARLINA-T2D, linagliptin was associated with significant improvements in glycemic control with a non-significant reduction in albuminuria and no evidence of renal adverse effects in a high-risk population of patients with T2D and early diabetic kidney disease. Although there was no conclusive evidence of renoprotective effects, previous research suggests that clinically apparent renal benefits might develop with longer term treatment. The results of ongoing trials with primary renal endpoints are awaited with interest.

Unsweetening the Heart: Possible Pleiotropic Effects of SGLT2 Inhibitors on Cardio and Cerebrovascular Alterations in Resistant Hypertensive Subjects

Resistant hypertension (RH) is a multifactorial disease associated with several target organ damage, such as microalbuminuria, left ventricular hypertrophy, and arterial stiffness. These subjects have high cardiovascular complications, especially when associated with diabetes condition. Sodium glucose cotransporter 2 (SGLT-2) inhibitors represent a new class of oral antidiabetic drugs that have shown positive effects in diabetics and even hypertensives subjects. Several studies demonstrated positive outcomes related to blood pressure levels, body weight, and glycemic control. Also found a reduction on microalbuminuria, cardiac and arterial remodeling process, and decrease in hospitalization care due heart failure. Despite these positive effects, the outcomes found for stroke were conflicted and tend neutral effect. Based on this, we sought to assess the pleiotropic effects of SGLT-2 inhibitors and the possible impact in RH subjects. In order to analyze the prospects of SGLT-2 inhibitors as a possible medication to complement the therapy manage of this high-risk class of patients.

Administration of RAS Inhibitor before the Onset of Diabetic Nephropathy Counteracts the Adverse Effect of Chronic Hyperglycemia and Reduces the Augmentation of Urinary Albumin Excretion: A Retrospective Clinical Study

It is very important to explore how we can reduce urinary albumin excretion which is an independent risk factor for ischemic heart disease. In this study, we retrospectively evaluated the effects of RAS inhibitor therapy on diabetic nephropathy in Japanese subjects whose urinary albumin levels were within normal range. We enrolled 100 subjects with type 2 diabetes who did not take any renin-angiotensin system (RAS) inhibitor. We defined the subjects taking RAS inhibitor for more than 3 years as RAS inhibitor group. RAS inhibitor exerted protective effect on the progression of urinary albumin excretion in subjects with type 2 diabetes without diabetic nephropathy. In addition, RAS inhibitor exerted more protective effects on renal function especially in subjects with poor glycemic control. In conclusion, RAS inhibitor could protect renal function against the deleterious effect of chronic hyperglycemia in Japanese subjects with type 2 diabetes even before the onset of diabetic nephropathy.

The natural compound 2,3,5,4'-tetrahydroxystilbene-2-O-β-d glucoside protects against adriamycin-induced nephropathy through activating the Nrf2-Keap1 antioxidant pathway

2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside (THSG) is an active compound extracted from Polygonum multiflorum Thunb. This herb and radix Polygoni Multiflori preparata have been used to treat arteriosclerosis, hyperlipidemia, hypercholesterolemia, and diabetes for thousands of years. This study aimed to investigate the protective effects of THSG in an Adriamycin (AD)-induced focal segmental glomerulosclerosis (FSGS) mouse model and the underlying mechanisms in an in vitro system. Mice were treated with THSG (2.5 and 10 mg/kg, oral gavage) for 24 consecutive days. On the third day, mice were intravenously given a single dose of AD (10 mg/kg). At the end of the experiment, plasma and kidney samples were harvested to evaluate the therapeutic effects of THSG. The potential mechanisms of THSG in protecting against AD-induced cytotoxicity were examined using a real-time polymerase chain reaction, immunoblots, lactate dehydrogenase assay, and a cellular oxidized-thiol detection system in a mouse mesangial cell line. In this study, THSG showed concentration-dependent protective effects in ameliorating the progression of AD-induced FSGS. THSG suppressed albuminuria and hypercholesterolemia and reduced the status of lipid peroxidation in urine, plasma, and kidney tissue samples. Furthermore, THSG protected against podocyte damage, reduced renal fibrotic gene expressions, and alleviated the severity of glomerulosclerosis. Treatment of mouse mesangial cells with THSG induced nuclear factor erythroid-derived 2-like 2 (Nrf2) nuclear translocation, increased heme oxygenase-1 and NAD(P)H:quinone oxidoreductase (NQO)-1 gene expressions, and reduced cellular thiol oxidation and resistance to AD-induced cytotoxicity. Silencing Nrf2 and its repressor protein, Kelch-like ECH-associated protein 1 (Keap1), abolished these protective effects of THSG. In conclusion, THSG can play a protective role in ameliorating the progression of FSGS in a mouse model through activation of the Nrf2-Keap1 antioxidant pathway. Although a well-designed therapeutic study is needed, THSG may be applied to manage chronic kidney disease.

Renal Ischemia-Reperfusion Injury in a Diabetic Monkey Model and Therapeutic Testing of Human Bone Marrow-Derived Mesenchymal Stem Cells

Clinically, acute kidney injury (AKI) episodes in diabetes mellitus (DM) patients are associated with a cumulative risk of developing end-stage renal disease. In this study, we asked whether the severity of AKI induced by renal ischemia-reperfusion injury (IRI) is more prominent in DM than in non-DM control using a cynomolgus monkey (Macaca fascicularis) model. We also investigated whether human bone marrow-derived mesenchymal stem cells (hBM-MSCs) infused via the renal artery could ameliorate renal IRI in DM monkeys. The experimental data, including mortality rate, histologic findings, and urinary albumin secretion indicate that the severity of AKI was greater in DM monkeys than in control animals. Moreover, histological findings and qRT-PCR analysis of Ngal mRNA in renal biopsy tissue showed that hBM-MSC promoted the recovery of tubular damage caused by AKI. Serum analysis also revealed that the level of albumin and ALT was increased 24 and 48 hours after AKI, respectively, suggesting that AKI induced acute liver injury. We suggest that this nonhuman primate model could provide essential information about the renal and nonrenal impairment related to DM and help determine the clinical usefulness of MSCs in AKI.

ACE Inhibitors and Statins in Adolescents with Type 1 Diabetes

BACKGROUND

Among adolescents with type 1 diabetes, rapid increases in albumin excretion during puberty precede the development of microalbuminuria and macroalbuminuria, long-term risk factors for renal and cardiovascular disease. We hypothesized that adolescents with high levels of albumin excretion might benefit from angiotensin-converting-enzyme (ACE) inhibitors and statins, drugs that have not been fully evaluated in adolescents.

METHODS

We screened 4407 adolescents with type 1 diabetes between the ages of 10 and 16 years of age and identified 1287 with values in the upper third of the albumin-to-creatinine ratios; 443 were randomly assigned in a placebo-controlled trial of an ACE inhibitor and a statin with the use of a 2-by-2 factorial design minimizing differences in baseline characteristics such as age, sex, and duration of diabetes. The primary outcome for both interventions was the change in albumin excretion, assessed according to the albumin-to-creatinine ratio calculated from three early-morning urine samples obtained every 6 months over 2 to 4 years, and expressed as the area under the curve. Key secondary outcomes included the development of microalbuminuria, progression of retinopathy, changes in the glomerular filtration rate, lipid levels, and measures of cardiovascular risk (carotid intima-media thickness and levels of high-sensitivity C-reactive protein and asymmetric dimethylarginine).

RESULTS

The primary outcome was not affected by ACE inhibitor therapy, statin therapy, or the combination of the two. The use of an ACE inhibitor was associated with a lower incidence of microalbuminuria than the use of placebo; in the context of negative findings for the primary outcome and statistical analysis plan, this lower incidence was not considered significant (hazard ratio, 0.57; 95% confidence interval, 0.35 to 0.94). Statin use resulted in significant reductions in total, low-density lipoprotein, and non-high-density lipoprotein cholesterol levels, in triglyceride levels, and in the ratio of apolipoprotein B to apolipoprotein A1, whereas neither drug had significant effects on carotid intima-media thickness, other cardiovascular markers, the glomerular filtration rate, or progression of retinopathy. Overall adherence to the drug regimen was 75%, and serious adverse events were similar across the groups.

CONCLUSIONS

The use of an ACE inhibitor and a statin did not change the albumin-to-creatinine ratio over time. (Funded by the Juvenile Diabetes Research Foundation and others; AdDIT ClinicalTrials.gov number, NCT01581476 .).

The Novel Compound Sul-121 Preserves Endothelial Function and Inhibits Progression of Kidney Damage in Type 2 Diabetes Mellitus in Mice

Diabetic nephropathy is still a common complication of type 2 diabetes mellitus (T2DM) and improvement of endothelial dysfunction (ED) and inhibition of reactive oxygen species (ROS) are considered important targets for new therapies. Recently, we developed a new class of compounds (Sul compounds) which inhibit mitochondrial ROS production. Here, we tested the therapeutic effects of Sul-121 on ED and kidney damage in experimental T2DM. Diabetic db/db and lean mice were implanted with osmotic pumps delivering Sul-121 (2.2 mg/kg/day) or vehicle from age 10 to 18 weeks. Albuminuria, blood pressure, endothelial mediated relaxation, renal histology, plasma creatinine, and H2O2 levels were assessed. Sul-121 prevented progression of albuminuria and attenuated kidney damage in db/db, as evidenced by lower glomerular fibronectin expression (~50%), decreased focal glomerular sclerosis score (~40%) and normalization of glomerular size and kidney weight. Further, Sul-121 restored endothelium mediated vasorelaxation through increased production of Nitric Oxide production and normalized plasma H2O2 levels. Sul-121 treatment in lean mice demonstrated no observable major side-effects, indicating that Sul-121 is well tolerated. Our data show that Sul-121 inhibits progression of diabetic kidney damage via a mechanism that involves restoration of endothelial function and attenuation of oxidative stress.

Liraglutide and Renal Outcomes in Type 2 Diabetes

BACKGROUND

In a randomized, controlled trial that compared liraglutide, a glucagon-like peptide 1 analogue, with placebo in patients with type 2 diabetes and high cardiovascular risk who were receiving usual care, we found that liraglutide resulted in lower risks of the primary end point (nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes) and death. However, the long-term effects of liraglutide on renal outcomes in patients with type 2 diabetes are unknown.

METHODS

We report the prespecified secondary renal outcomes of that randomized, controlled trial in which patients were assigned to receive liraglutide or placebo. The secondary renal outcome was a composite of new-onset persistent macroalbuminuria, persistent doubling of the serum creatinine level, end-stage renal disease, or death due to renal disease. The risk of renal outcomes was determined with the use of time-to-event analyses with an intention-to-treat approach. Changes in the estimated glomerular filtration rate and albuminuria were also analyzed.

RESULTS

A total of 9340 patients underwent randomization, and the median follow-up of the patients was 3.84 years. The renal outcome occurred in fewer participants in the liraglutide group than in the placebo group (268 of 4668 patients vs. 337 of 4672; hazard ratio, 0.78; 95% confidence interval [CI], 0.67 to 0.92; P=0.003). This result was driven primarily by the new onset of persistent macroalbuminuria, which occurred in fewer participants in the liraglutide group than in the placebo group (161 vs. 215 patients; hazard ratio, 0.74; 95% CI, 0.60 to 0.91; P=0.004). The rates of renal adverse events were similar in the liraglutide group and the placebo group (15.1 events and 16.5 events per 1000 patient-years), including the rate of acute kidney injury (7.1 and 6.2 events per 1000 patient-years, respectively).

CONCLUSIONS

This prespecified secondary analysis shows that, when added to usual care, liraglutide resulted in lower rates of the development and progression of diabetic kidney disease than placebo. (Funded by Novo Nordisk and the National Institutes of Health; LEADER ClinicalTrials.gov number, NCT01179048 .).

Rho-Kinase Blockade Attenuates Podocyte Apoptosis by Inhibiting the Notch Signaling Pathway in Diabetic Nephropathy

Podocyte apoptosis is a key process in the onset of diabetic nephropathy. A significant body of evidence shows that the Notch signaling pathway plays a central role in this process. We found that Rho-kinase mediates transforming growth factor β (TGF-β)-induced Notch ligand Jag1 expression. Importantly, TGF-β-mediated podocyte apoptosis was attenuated by Rho-kinase inhibition. Mechanistically, Rho-kinase regulated Jag1 induction via the extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) but not Smad pathways. Consistently, the Rho-kinase inhibitor fasudil prevented albuminuria and the urinary excretion of nephrin in db/db mice and reduced the prevalence of podocyte apoptosis and Jag1 expression. Finally, the expression of Jag1 and apoptosis markers such as Bax and cyclin-dependent kinase inhibitor 1A (CDKN1A) was decreased in podocytes derived from db/db mice treated with fasudil. The present study provides evidence that Rho-kinase plays a key role in podocyte apoptosis. Rho-kinase is an attractive therapeutic target for diabetic nephropathy.

Effect of valsartan on kidney outcomes in people with impaired glucose tolerance

AIMS

To examine the effect of valsartan on kidney outcomes in patients with impaired glucose tolerance (IGT).

METHODS

In a double-blind randomized trial, 9306 patients with IGT were assigned to valsartan (160 mg daily) or placebo. The co-primary endpoints were the development of diabetes and two composite cardiovascular outcomes. Prespecified renal endpoints included: the composite of renal death, end-stage renal disease (ESRD) or doubling of serum creatinine; estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m² ; hospitalization for renal failure; and progression from normoalbuminuria to microalbuminuria, microalbuminuria to macroalbuminuria, and normoalbuminuria to macroalbuminuria. The median follow-up was 6.2 years.

RESULTS

Valsartan reduced the incidence of diabetes but not cardiovascular events. In the valsartan group, 25/4631 patients (0.5%), vs 26/4675 (0.6%) patients in the placebo group, developed ESRD or experienced doubling of serum creatinine (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.55-1.66; P  = .87). Few patients in either group developed an eGFR of ≤30 mL/min/1.73 m² or had a renal hospitalization. Fewer patients on valsartan (237/4084 [5.8%]) than on placebo (342/4092 [8.4%]) developed microalbuminuria (HR 0.68, 95% CI 0.57-0.80; P  < .0001), and fewer valsartan-treated patients developed macroalbuminuria. Overall, urinary albumin-to-creatinine ratio (UACR) was 11% lower with valsartan (95% CI 8-13; P  < .0001) and 9% lower (95% CI 6-11; P  < .0001) after adjusting for both glucose and blood pressure.

CONCLUSIONS

The effect of valsartan on UACR was not wholly explained by change in blood pressure or glucose. Valsartan reduced the incidence of microalbuminuria in IGT without increasing the incidence of hyperkalaemia or renal dysfunction compared with placebo.

Antagonism of vasopressin V2 receptor improves albuminuria at the early stage of diabetic nephropathy in a mouse model of type 2 diabetes

AIMS

Vasopressin is increased in diabetes and was shown to contribute to development of diabetic nephropathy through V2 receptor (V2R) activation in an experimental model of type 1 diabetes. The role of V2R in type 2 diabetes remains undocumented. This study addresses the issue in a mouse model of type 2 diabetes.

METHODS

Male obese diabetic db/db mice were treated for 12weeks with a selective V2R antagonist (SR121463) and compared to non-treated db/db and non-diabetic db/m mice. All animals were previously uninephrectomized.

RESULTS

The V2R antagonist did not alter glycemia or glycosuria in db/db mice. It induced a two-fold increase in urine output and a 52% decrease in urine osmolality compared to non-treated db/db mice. After four weeks of treatment urinary albumin to creatinine ratio was 50% lower in treated mice compared to non-treated mice, and remained significantly lower until end of experiment. Glomerular filtration rate increased significantly over time in non-treated db/db mice but remained stable in treated mice.

CONCLUSIONS

This study shows that vasopressin contributes to albuminuria and glomerular hyperfiltration via V2R in a mouse model of type 2 diabetes. It documents causality behind the association of vasopressin with renal disease observed in diabetic patients.

Differential Effects of Dapagliflozin on Cardiovascular Risk Factors at Varying Degrees of Renal Function

BACKGROUND AND OBJECTIVE

Sodium glucose cotransporter 2 inhibition with dapagliflozin decreases hemoglobin A1c (HbA1c), body weight, BP, and albuminuria (urinary albumin-to-creatinine ratio). Dapagliflozin also modestly increases hematocrit, likely related to osmotic diuresis/natriuresis. Prior studies suggest that the HbA1c-lowering effects of dapagliflozin attenuate at lower eGFR. However, effects on other cardiovascular risk factors at different eGFR levels are incompletely understood.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This pooled analysis of 11 phase 3 clinical trials assessed changes in HbA1c, body weight, BP, hematocrit, and urinary albumin-to-creatinine ratio with placebo (n=2178) or dapagliflozin 10 mg (n=2226) over 24 weeks in patients with type 2 diabetes according to baseline eGFR (eGFR≥45 to <60 ml/min per 1.73 m2, eGFR≥60 to <90 ml/min per 1.73 m2, and eGFR≥90 ml/min per 1.73 m2).

RESULTS

Compared with placebo, reductions in HbA1c with dapagliflozin were 0.6%, 0.5%, and 0.3%, respectively, for each consecutive lower eGFR subgroup (P value interaction <0.001). Effects of dapagliflozin on hematocrit, body weight, and BP were similar regardless of baseline eGFR, suggesting that effects potentially related to volume and natriuresis are eGFR independent. Moreover, among individuals with baseline urinary albumin-to-creatinine ratio ≥30 mg/g, placebo-adjusted reductions in urinary albumin-to-creatinine ratio were larger in the lowest eGFR subgroup (P value interaction <0.001). Adverse events occurred more frequently in the lowest eGFR subgroup; this was true for both dapagliflozin- and placebo-treated patients.

CONCLUSIONS

The HbA1c-lowering effects of dapagliflozin decrease as renal function declines. However, dapagliflozin consistently decreases body weight, BP, and urinary albumin-to-creatinine ratio regardless of eGFR. These effects in conjunction with the finding of similar effects on hematocrit, a proxy for volume contraction, suggest that the effects of dapagliflozin are partly mediated via nonglucosuric-dependent mechanisms.

The effects of atrasentan on urinary metabolites in patients with type 2 diabetes and nephropathy

We assessed the effect of atrasentan therapy on a pre-specified panel of 13 urinary metabolites known to reflect mitochondrial function in patients with diabetic kidney disease. This post-hoc analysis was performed using urine samples collected during the RADAR study which was a randomized, double-blind, placebo-controlled trial that tested the effects of atrasentan on albuminuria reduction in patients with type 2 diabetes and nephropathy. At baseline, 4 of the 13 metabolites, quantified by gas-chromatography mass spectrometry, were below detectable levels, and 6 were reduced in patients with eGFR < 60 mL/min/1.73 m² . After 12 weeks of atrasentan treatment in patients with eGFR < 60 mL/min/1.73 m² , a single-value index of the metabolites changed by -0.31 (95%CI -0.60 to -0.02; P  = .035), -0.08 (-12 to 0.29; P  = .43) and 0.01 (-0.21 to 0.19; P  = .913) in placebo, atrasentan 0.75 and 1.25 mg/d, respectively. The metabolite index difference compared to placebo was 0.13 (-0.17 to 0.43; P  = .40) and 0.35 (0.05-0.65; P  = .02) for atrasentan 0.75 and 1.25 mg/d, respectively. These data corroborate previous findings of mitochondrial dysfunction in patients with type 2 diabetes, nephropathy and eGFR < 60 mL/min/1.73 m² , suggesting that atrasentan may prevent the progression of mitochondrial dysfunction common to this specific patient population. Future studies of longer treatment duration with atrasentan are indicated.