Whole-body insulin clearance in people with type 2 diabetes and normal kidney function:Relationship with glomerular filtration rate, renal plasma flow, and insulin sensitivity

OBJECTIVE: Kidney insulin clearance, proposed to be the main route of extra-hepatic insulin clearance, occurs in tubular cells following glomerular filtration and peritubular uptake, a process that may be impaired in people with type 2 diabetes (T2D) and/or impaired kidney function. Human studies that investigated kidney insulin clearance are limited by the invasive nature of the measurement. Instead, we evaluated relationships between whole-body insulin clearance, and gold-standard measured kidney function and insulin sensitivity in adults with T2D and normal kidney function. RESEARCH DESIGN AND METHODS: We determined insulin, inulin/iohexol and para-aminohippuric acid (PAH) clearances during a hyperinsulinemic-euglycemic clamp to measure whole-body insulin clearance and kidney function. Insulin sensitivity was expressed by glucose infusion rate (M value). Associations between whole-body insulin clearance, kidney function and insulin sensitivity were examined using univariable and multivariable linear regressions models. RESULTS: We investigated 44 predominantly male (77%) T2D adults aged 63 ± 7, with fat mass 34.5 ± 9 kg, lean body mass 63.0 ± 11.8 kg, and HbA1c 7.4 ± 0.6%. Average whole-body insulin clearance was 1188 ± 358 mL/min. Mean GFR was 110 ± 22 mL/min, mean ERPF 565 ± 141 mL/min, and M value averaged 3.9 ± 2.3 mg/min. Whole-body insulin clearance was positively correlated with lean body mass, ERPF and insulin sensitivity, but not with GFR. ERPF explained 6% of the variance when entered in a nested multivariable linear regression model op top of lean body mass (25%) and insulin sensitivity (15%). CONCLUSIONS: In adults with T2D and normal kidney function, whole-body insulin clearance was predicted best by lean body mass and insulin sensitivity, and to a lesser extent by ERPF. GFR was not associated with whole-body insulin clearance. In contrast to prior understanding, this suggests that in this population kidney insulin clearance may not play such a dominant role in whole-body insulin clearance

Renoprotection in diabetic kidney disease: Can incretin-based therapies deliver?

Purpose of reviewIncretin-based therapies mimic or augment the gut-hormone glucagon-like peptide (GLP)-1 and, due to their glucose-lowering potential and beneficial safety profile, as well as their cardiovascular safety and/or protection, are prescribed on a large scale to treat individuals with type 2 diabetes (T2D). However, whether the two drug-classes that belong to this category, respectively GLP-1 receptor agonists and dipeptidyl peptidase (DPP)-4 inhibitors, also reduce the risk of diabetic kidney disease (DKD) is at present heavily debated. This review aims to discuss the current evidence.Recent findingsEvidence from land-mark cardiovascular safety trials, conducted in people with T2D at high-cardiovascular risk but with normal kidney function, suggest that both drug-classes have excellent renal safety profiles. In contrast to DPP-4 inhibitors, it seems that GLP-1 receptor agonists reduce albuminuria and possibly induce a reduction of estimated glomerular filtration rate decline. However, the trials were not properly designed to test renal outcomes.SummaryA dedicated renal trial involving a GLP-1 receptor agonist has recently commenced and will answer the question whether these drugs will be effective to reduce DKD. Moreover, ongoing mechanism-of-Action studies are focusing on the renal physiological effects of GLP-1, as the effects on particularly albuminuria reduction remain currently unexplained

SGLT2 inhibitors’ interaction with other renoactive drugs in type 2 diabetes patients: still a lot to learn

The first cardiovascular (CV) safety trial conducted with a sodium-glucose cotransporter (SGLT)-2 inhibitor, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients—Removing Excess Glucose (EMPA-REG OUTCOME), reported not only remarkable risk reductions in CV outcome, but also impressive improvements in renal outcome. Changes in renal hemodynamics could be involved in the benefit of SGLT2 inhibitors on renal outcomes. Considering that all patients of EMPA-REG OUTCOME had established atherosclerotic CV disease at baseline, many patients were also treated with several CV drugs at baseline, including RAS blockers, diuretics, calcium-channel blockers, and nonsteroidal anti-inflammatory drugs. These drugs also impact renal physiology and possibly renal outcome, which could cause relevant drug–drug interactions. This topic is addressed in this issue of Kidney International by Mayer and colleagues. In their manuscript, the impact of empagliflozin on kidney function, renal outcome, and renal safety is presented with stratification for background therapy. Although the beneficial effects of empagliflozin and its safety profile are consistent among all groups, we wonder, do we really understand the renal effects of all these drugs in type 2 diabetes (T2D) patients as studied in the large outcome trials

SGLT2 inhibitors’ interaction with other renoactive drugs in type 2 diabetes patients: still a lot to learn

The first cardiovascular (CV) safety trial conducted with a sodium-glucose cotransporter (SGLT)-2 inhibitor, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients—Removing Excess Glucose (EMPA-REG OUTCOME), reported not only remarkable risk reductions in CV outcome, but also impressive improvements in renal outcome. Changes in renal hemodynamics could be involved in the benefit of SGLT2 inhibitors on renal outcomes. Considering that all patients of EMPA-REG OUTCOME had established atherosclerotic CV disease at baseline, many patients were also treated with several CV drugs at baseline, including RAS blockers, diuretics, calcium-channel blockers, and nonsteroidal anti-inflammatory drugs. These drugs also impact renal physiology and possibly renal outcome, which could cause relevant drug–drug interactions. This topic is addressed in this issue of Kidney International by Mayer and colleagues. In their manuscript, the impact of empagliflozin on kidney function, renal outcome, and renal safety is presented with stratification for background therapy. Although the beneficial effects of empagliflozin and its safety profile are consistent among all groups, we wonder, do we really understand the renal effects of all these drugs in type 2 diabetes (T2D) patients as studied in the large outcome trials

The incretin pathway as a therapeutic target in diabetic kidney disease: a clinical focus on GLP-1 receptor agonists

Diabetic kidney disease (DKD) remains the main cause for chronic kidney disease (CKD) and end-stage kidney disease (ESKD) worldwide. Both CKD and ESKD lead to major increases in risk of cardiovascular disease and death in people with diabetes. Despite optimal management of lifestyle, glucose levels and hypertension, residual risk remains high, indicating that additional therapies to mitigate the burden of the disease are desired. In past decades, new treatment options for the management of diabetes have emerged, of which some have showed promising renoprotective potential. This review discusses current understanding of the renal effects of glucagon-like peptide receptor agonists and their potential use in prevention and treatment of DKD

SGLT2 Inhibitors in Combination Therapy: From Mechanisms to Clinical Considerations in Type 2 Diabetes Management

The progressive nature of type 2 diabetes (T2D) requires practitioners to periodically evaluate patients and intensify glucose-lowering treatment once glycemic targets are not attained. With guidelines moving away from a one-size-fits-all approach toward setting patient-centered goals and allowing flexibility in choos in ga second-/third-line drug from the growing number of U.S. Food and Drug Administration-approved glucose-lowering agents, keen personalized management in T2D has become a challenge for health care providers in daily practice. Among the newer generation of glucose-lowering drug classes, sodium-glucose cotransporter 2 inhibitors (SGLT2is), which enhance urinary glucose excretion to lower hyper-glycemia, have made an imposing entrance to the T2D treatment armamentarium. Given their unique insulin-independent mode of action and their favorable efficacy-to-adverse event profile and given their marked benefits on cardiovascular-renal outcome in moderate-to-high risk T2D patients, which led to updates of guidelines and product monographs, the role of this drug class in multidrug regimes is promising. However, despite many speculations based on pharmacokinetic and pharmacodynamic properties, physiological reasoning, and potential synergism, the effects of these agents in terms of glycemic and pleiotropic efficacy when combined with other glucose-lowering drug classes are largely understudied. In this perspective, we review the currently emerging evidence, discuss prevailing hypotheses, and elaborate on necessary future studies to clarify the potential risks and benefits of using an SGLT2i in dual combination with metformin and triple combination with a glucagon-like peptide 1 receptor agonist, dipeptidyl peptidase 4 inhibitor, or other glucose-lowering agent that is recommended by the American Diabetes Association and European Association for the Study of Diabetes (i.e., a sulfonylurea, thiazolidinedione, or insulin) to treat patients with T2D

Erratum: SGLT2 inhibitors in combination therapy: From mechanisms to clinical considerations in type 2 diabetes management. (Diabetes Care (2018) 41 (1543–1556) DOI: 10.2337/dc18-0588)

In the article cited above, Fig. 3 was replaced. The data in the HbA1c (%) panel under 8.9 baseline was corrected. The online version of the article (https://doi.org/10.2337/dc18-0588) has been corrected