Glomerular filtration rate as a kidney outcome of diabetic kidney disease: a focus on new antidiabetic drugs

Steps to understanding diabetes kidney disease: a focus on metabolomics

Diabetic nephropathy (DN), a leading cause of chronic kidney disease and end-stage kidney disease (ESKD), poses global health challenges given its increasing prevalence. DN increases the risk of mortality and cardiovascular events. Early identification and appropriate DN management are crucial. However, current diagnostic methods rely on general traditional markers, highlighting the need for DN-specific diagnostics. Metabolomics, the study of small molecules produced by metabolic activity, promises to identify specific biomarkers that distinguish DN from other kidney diseases, decode the underlying disease mechanisms, and predict the disease course. Profound changes in metabolic pathways are apparent in individuals with DN, alterations in the tricarboxylic acid cycle and amino acid and lipid metabolism, suggestive of mitochondrial dysfunction. Metabolomics aids prediction of chronic kidney disease progression; several metabolites serve as indicators of renal functional decline and the risk of ESKD. Integration of such information with other omics data will further enhance our understanding of DN, paving the way to personalized treatment. In summary, metabolomics and multi-omics offer valuable insights into DN and are promising diagnostic and prognostic tools.

Triglyceride-Glucose Index and Its Correlates: Associations with Serum Creatinine and Estimated Glomerular Filtration Rate in a Cross-Sectional Study from CHARLS 2011-2015

Background: Chronic kidney disease (CKD) has emerged as a significant global public health challenge, and the estimated glomerular filtration rate (eGFR) is widely used due to its convenience, low cost, and broad clinical applicability. Concurrently, insulin resistance (IR) serves as a crucial marker of metabolic disturbance, and alternative indicators have garnered increasing attention in CKD research in recent years. Objective: This study aims to investigate the relationship between IR-related indices (TyG index, TyG-BMI index, and TyG-WC index) and serum creatinine levels, as well as the eGFR, with the intention of uncovering their potential roles in the assessment of renal function. Methods: We analyzed nationally representative cross-sectional data from a cohort of individuals aged 45 and above in China, comprising 11,608 participants. Participants were categorized into different groups based on quartiles of the TyG index, and multiple factors, including gender, age, lifestyle, and co-morbidities, were adjusted for using linear regression models. Results: By linear regression, TyG, TyG-BMI, and TyG-WC indices were significantly positively correlated with serum creatinine and significantly negatively correlated with eGFR. Results showed similar trends when TyG, TyG-BMI, and TyG-WC indices were used as categorical variables. In the fully adjusted model, the highest quartile of serum creatinine was higher than the first quartile for TyG, TyG-BMI, and TyG-WC indices, with β values of 2.673, 3.67, and 1.937 mg/dL, respectively; the highest quartile of eGFR was lower than the first quartile, with β values of -2.4, -2.955, and -1.823 mL/min/1.73 m2. P values were statistically significant. Conclusions: This study indicates a consistent correlation between the TyG index and its related indices with serum creatinine levels and eGFR among the middle aged and elderly population in China. These findings suggest the potential utility of these indices in early screening and management of the risk of chronic kidney disease.

Renoprotective Mechanism of Sodium-Glucose Cotransporter 2 Inhibitors: Focusing on Renal Hemodynamics

Diabetic kidney disease (DKD) is a prevalent renal complication of diabetes mellitus that ultimately develops into end-stage kidney disease (ESKD) when not managed appropriately. Substantial risk of ESKD remains even with intensive management of hyperglycemia and risk factors of DKD and timely use of renin-angiotensin-aldosterone inhibitors. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce hyperglycemia primarily by inhibiting glucose and sodium reabsorption in the renal proximal tubule. Currently, their effects expand to prevent or delay cardiovascular and renal adverse events, even in those without diabetes. In dedicated renal outcome trials, SGLT2 inhibitors significantly reduced the risk of composite renal adverse events, including the development of ESKD or renal replacement therapy, which led to the positioning of SGLT2 inhibitors as the mainstay of chronic kidney disease management. Multiple mechanisms of action of SGLT2 inhibitors, including hemodynamic, metabolic, and anti-inflammatory effects, have been proposed. Restoration of tubuloglomerular feedback is a plausible explanation for the alteration in renal hemodynamics induced by SGLT2 inhibition and for the associated renal benefit. This review discusses the clinical rationale and mechanism related to the protection SGLT2 inhibitors exert on the kidney, focusing on renal hemodynamic effects.