Cost of treating diabetic kidney disease

The Impact of SGLT2 Inhibitors in the Heart and Kidneys Regardless of Diabetes Status

Chronic Kidney Disease (CKD) and Cardiovascular Disease (CVD) are two devastating diseases that may occur in nondiabetics or individuals with diabetes and, when combined, it is referred to as cardiorenal disease. The impact of cardiorenal disease on society, the economy and the healthcare system is enormous. Although there are numerous therapies for cardiorenal disease, one therapy showing a great deal of promise is sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors. The SGLT family member, SGLT2, is often implicated in the pathogenesis of a range of diseases, and the dysregulation of the activity of SGLT2 markedly effects the transport of glucose and sodium across the luminal membrane of renal cells. Inhibitors of SGLT2 were developed based on the antidiabetic action initiated by inhibiting renal glucose reabsorption, thereby increasing glucosuria. Of great medical significance, large-scale clinical trials utilizing a range of SGLT2 inhibitors have demonstrated both metabolic and biochemical benefits via numerous novel mechanisms, such as sympathoinhibition, which will be discussed in this review. In summary, SGLT2 inhibitors clearly exert cardio-renal protection in people with and without diabetes in both preclinical and clinical settings. This exciting class of inhibitors improve hyperglycemia, high blood pressure, hyperlipidemia and diabetic retinopathy via multiple mechanisms, of which many are yet to be elucidated.

Initiation of sodium-glucose cotransporter-2 inhibitors at lower HbA1c threshold attenuates eGFR decline in type 2 diabetes patients with and without cardiorenal disease: A propensity-matched cohort study

AIM

To examine the association of initiation of sodium-glucose cotransporter-2 inhibitors (SGLT2i) at lower glycemic threshold with decline in estimated-glomerular filtration rate (eGFR).

METHODS

We analyzed a prospective cohort of Chinese patients with type 2 diabetes from Hong Kong. Patients initiating SGLT2i at HbA1c < 7.5 % (lower-HbA1c) versus ≥ 7.5 % (higher-HbA1c) were matched using 1:1 propensity score. We compared annual eGFR changes in the lower-HbA1c and higher-HbA1c groups using linear mixed-effect models. Binary logistic regression was used to explore associations of SGLT2i initiation at lower HbA1c with odds of rapid eGFR decline (>4% per year).

RESULTS

Among 3384 patients with a median follow-up of 1.9 years, the mean age was 60.2 ± 11.5 years and 62.1 % were male. The lower-HbA1c and higher-HbA1c groups had baseline HbA1c (%) of 6.9 ± 0.5 and 9.0 ± 1.3 respectively, with similar pre-index annual eGFR decline. The lower-HbA1c group had a slower post-index annual eGFR decline than the higher-HbA1c group (-0.99 versus -1.63 mL/min/1.73 m², p < 0.001). Overall, the lower-HbA1c group had lower odds of rapid eGFR decline (OR = 0.15, 95 % CI: 0.07-0.29). Greater renoprotection from SGLT2i initiation at lower-HbA1c was observed in those with baseline eGFR < 60 mL/min/1.73 m², albuminuria and/or treatment with renin-angiotensin-system inhibitors or insulin.

CONCLUSIONS

In this real-world study, SGLT2i initiation at HbA1c < 7.5 % was associated with slower eGFR decline especially in high risk patients, supporting the potential renal benefits of SGLT2i initiation at lower glycemic thresholds.

The Effect of SGLT2 Inhibition on Diabetic Kidney Disease in a Model of Diabetic Retinopathy

Diabetic kidney disease (DKD) is a chronic disorder characterized by elevated urine albumin excretion, reduced glomerular filtration rate, or both. At present, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers are the standard care for the treatment of DKD, resulting in improved outcomes. However, alternative treatments may be required because although the standard treatments have been found to slow the progression of DKD, they have not been found to halt the disease. In the past decade, sodium glucose co-transporter 2 (SGLT2) inhibitors have been widely researched in the area of cardiovascular disease and diabetes and have been shown to improve cardiovascular outcomes. SGLT2 inhibitors including canagliflozin and dapagliflozin have been shown to slow the progression of kidney disease. There is currently an omission of literature where three SGLT2 inhibitors have been simultaneously compared in a rodent diabetic model. After diabetic Akimba mice were treated with SGLT2 inhibitors for 8 weeks, there was not only a beneficial impact on the pancreas, signified by an increase in the islet mass and increased plasma insulin levels, but also on the kidneys, signified by a reduction in average kidney to body weight ratio and improvement in renal histology. These findings suggest that SGLT2 inhibition promotes improvement in both pancreatic and kidney health.

ERK and p38 MAPK inhibition controls NF-E2 degradation and profibrotic signaling in renal proximal tubule cells

AIMS

Transforming growth factor-β (TGF-β) mediates fibrotic manifestations of diabetic nephropathy. We demonstrated proteasomal degradation of anti-fibrotic protein, nuclear factor-erythroid derived 2 (NF-E2), in TGF-β treated human renal proximal tubule (HK-11) cells and in diabetic mouse kidneys. The current study examined the role of mitogen-activated protein kinase (MAPK) pathways in mediating NF-E2 proteasomal degradation and stimulating profibrotic signaling in HK-11 cells.

MAIN METHODS

HK-11 cells were pretreated with vehicle or appropriate proteasome and MAPK inhibitors, MG132 (0.5 μM), SB203580 (1 μM), PD98059 (25 μM) and SP600125 (10 μM), respectively, followed by treatment with/without TGF-β (10 ng/ml, 24 h). Cell lysates and kidney homogenates from FVB and OVE26 mice treated with/without MG132 were immunoblotted with appropriate antibodies. pUse vector and pUse-NF-E2 cDNA were transfected in HK-11 cells and effects of TGF-β on JNK MAPK phosphorylation (pJNK) was examined.

KEY FINDINGS

We demonstrated activation of p38, ERK, and JNK MAPK pathways in TGF-β treated HK-11 cells. Dual p38 and ERK MAPK blockade prevented TGF-β-induced pSer82Hsp27, fibronectin and connective tissue growth factor (CTGF) expression while preserving NF-E2 expression. Blockade of JNK MAPK inhibited TGF-β-induced CTGF expression without preserving NF-E2 expression. MG132 treatment prevented TGF-β-induced pJNK in HK-11 cells and in type 1 diabetic OVE26 mouse kidneys, demonstrating that TGF-β- and diabetes-induced pJNK occurs downstream of proteasome activation. A direct role for NF-E2 in modulating pJNK activation was demonstrated by NF-E2 over-expression.

SIGNIFICANCE

ERK and p38 MAPK promotes NF-E2 proteasomal degradation while proteasome activation promotes pJNK and profibrotic signaling in renal proximal tubule cells.

Cost-Effectiveness of Empagliflozin in Patients With Diabetic Kidney Disease in the United States: Findings Based on the EMPA-REG Outcome Trial

RATIONALE & OBJECTIVE

Benefits of sodium-glucose co-transporter 2 inhibitors on kidney outcomes have been demonstrated in clinical trials. Among patients with type 2 diabetes and established cardiovascular (CV) disease enrolled in EMPA-REG Outcome Study (NCT01131676), empagliflozin added to standard of care (SoC) reduced the risk of incident or worsening nephropathy compared to SoC alone. This analysis evaluated the cost-effectiveness of empagliflozin versus SoC alone in the subpopulation with diabetic kidney disease (DKD) from the perspective of United States (US) commercial insurers and Medicare.

STUDY DESIGN

Discrete event simulation model.

SETTING & POPULATION

Patients with DKD in a US healthcare system.

INTERVENTIONS

Empagliflozin 10 or 25 mg with SoC versus SoC alone. SoC included glucose-lowering therapies and medications to treat CV risk factors.

OUTCOMES

Incremental cost-effectiveness ratios (ICERs, 2020 US dollars per quality-adjusted life-year [QALY] gained). Costs and QALYs were discounted 3.0%/year. Model, Perspective, & Timeframe: Cost-effectiveness analysis, commercial insurers and Medicare perspective, lifetime horizon.

RESULTS

The ICER of empagliflozin with SoC versus SoC alone was $25,974/QALY. Empagliflozin added 0.67 QALYs and $17,322/patient over a lifetime horizon. Results were driven by fewer clinical events (including CV death, heart failure [HF] hospitalization, albuminuria progression, and a composite kidney outcome) experienced by patients receiving empagliflozin with SoC versus SoC alone. Results were sensitive to rates of CV death, non-fatal MI, and HF hospitalization, as well as to drug costs, and time horizon. Probabilistic sensitivity analyses indicated 91% of simulations falling below $50,000/QALY.

LIMITATIONS

The EMPA-REG Outcome Study was not powered to assess treatment benefits in a subgroup and excluded patients with estimated glomerular filtration rate <30 mL/min/1.73m².

CONCLUSION

Based on EMPA-REG Outcome Study, this cost-effectiveness analysis suggests that for commercial insurers and Medicare, adding empagliflozin to SoC may be a cost-effective treatment option for patients with DKD.

Saez AP, Mendoza P, Jara C, Cappelli C, Suarez R, Oyarzún C, Quezada C, San Martín R. Intraglomerular Monocyte/Macrophage Infiltration and Macrophage-Myofibroblast Transition during Diabetic Nephropathy Is Regulated by the A2B Adenosine Receptor

Diabetic nephropathy (DN) is considered the main cause of kidney disease in which myofibroblasts lead to renal fibrosis. Macrophages were recently identified as the major source of myofibroblasts in a process known as macrophage-myofibroblast transition (MMT). Adenosine levels increase during DN and in vivo administration of MRS1754, an antagonist of the A2B adenosine receptor (A2BAR), attenuated glomerular fibrosis (glomerulosclerosis). We aimed to investigate the association between A2BAR and MMT in glomerulosclerosis during DN. Kidneys/glomeruli of non-diabetic, diabetic, and MRS1754-treated diabetic (DM+MRS1754) rats were processed for histopathologic, transcriptomic, flow cytometry, and cellular in vitro analyses. Macrophages were used for in vitro cell migration/transmigration assays and MMT studies. In vivo MRS1754 treatment attenuated the clinical and histopathological signs of glomerulosclerosis in DN rats. Transcriptomic analysis demonstrated a decrease in chemokine-chemoattractants/cell-adhesion genes of monocytes/macrophages in DM+MRS1754 glomeruli. The number of intraglomerular infiltrated macrophages and MMT cells increased in diabetic rats. This was reverted by MRS1754 treatment. In vitro cell migration/transmigration decreased in macrophages treated with MRS1754. Human macrophages cultured with adenosine and/or TGF-β induced MMT, a process which was reduced by MRS1754. We concluded that pharmacologic blockade of A2BAR attenuated some clinical signs of renal dysfunction and glomerulosclerosis, and decreased intraglomerular macrophage infiltration and MMT in DN rats.