Limitations and future treatment options in type 2 diabetes with renal impairment

Evaluation of Effect of Montelukast in the Model of Streptozotocin Induced Diabetic Nephropathy in Rats

Background

Diabetic nephropathy is a progressive condition and a leading cause of end-stage renal disease. Oxidative stress and inflammation play an important role in its pathogenesis. In pre-clinical studies, Montelukast had shown renoprotective and anti-oxidant properties, hence the study was planned to evaluate the effect of Montelukast in a Streptozotocin (STZ) induced model of diabetic nephropathy.

Methods

40 Wistar rats of either sex were randomly divided into four groups viz. 1. Vehicle control group, 2. Enalapril (5 mg/kg), 3. Montelukast low-dose (10 mg/kg) and 4. High-dose (20 mg/kg) group. On day 1, diabetes was induced using a single dose of STZ (60 mg/kg) intraperitoneally. Diabetes induction was verified based on fasting blood glucose (FBG) levels on day 7 and from day 8 to day 42, rats were given study drugs. FBG, serum creatinine, blood urea nitrogen (BUN) and urine microalbumin levels were assessed pre-study and post-study. Assessments of kidney malondialdehyde (MDA), reduced glutathione (GSH) and renal histopathology were carried out at the end of the study.

Results

Montelukast 10 mg/kg group showed significantly lower urine microalbumin levels compared to the vehicle control group (p < 0.05). Montelukast 20 mg/kg group showed significantly lower levels of FBG, serum creatinine, BUN and urine microalbumin compared to the vehicle control group (p < 0.05). In addition, Montelukast 20 mg/kg group also showed better effects on kidney MDA and GSH levels (p < 0.05) and histopathological scores compared to the vehicle control group.

Conclusion

Montelukast showed a protective effect in the model of diabetic nephropathy because of its antioxidant effect.

Telemedicine assists in the management of proatherogenic dyslipidemia and postprandial glucose variability in patients with type 2 diabetes mellitus: a cross-sectional study

OBJECTIVE

Coronary heart disease (CHD) is a prevalent complication of type 2 diabetes mellitus (T2DM). The proatherogenic low-density lipoprotein (LDL) cholesterol is an established risk factor of cardiovascular disease, and evidence also suggests that postprandial plasma glucose (PPG) levels closely delineate CHD mortality in diabetes. The investigators hypothesized that the addition of telehealth consultation to standard antidiabetic therapy may help to reduce postprandial glucose variability and plasma LDL cholesterol levels in patients with T2DM.

METHODS

This cross-sectional study enrolled patients with newly diagnosed T2DM who received standard antidiabetic therapy with or without additional telehealth consultation. Participants received blood tests for plasma lipid profile and glucose levels at the diagnosis of diabetes and after 1 month of therapeutic intervention. Laboratory results were compared between treatment groups to determine the efficacy of complementary telehealth consultation.

RESULTS

In this study, 375 participants were enrolled. The standard treatment group had considerably greater levels of plasma LDL cholesterol than recipients of telehealth consultation (110 mg/dL vs 93.1 mg/dL, P < 0.001). Moreover, patients receiving standard treatment had greater levels of fasting plasma glucose (104 mg/dL vs 98.5 mg/dL, P = 0.027), 2-h PPG (169 mg/dL vs 111 mg/dL, P < 0.001), and postprandial glucose variability (65.4 mg/dL vs 12.8 mg/dL, P < 0.001) than participants under telehealth consultation.

CONCLUSIONS

Telemedicine in addition to standard antidiabetic therapy helped to reduce plasma LDL cholesterol levels and postprandial glucose variability in patients with newly diagnosed T2DM. Therefore, telehealth consultation is a suitable complement to pharmacologic therapy for diabetic patients to assist in the management of proatherogenic dyslipidemia and postprandial glucose variability.

Assessment of Second-Generation Diabetes Medication Initiation Among Medicare Enrollees From 2007 to 2015

IMPORTANCE

Little is known about how new and expensive drugs diffuse into practice affects health care costs.

OBJECTIVE

To describe the variation in second-generation diabetes drug use among Medicare enrollees between 2007 and 2015.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, cross-sectional study included data from 100% of Medicare Parts A, B, and D enrollees who first received diabetes drug therapy from January 1, 2007, to December 31, 2015. Patients with type 1 diabetes were excluded. Data were analyzed beginning in the spring of 2018, and revisions were completed in 2019.

EXPOSURES

For each patient, the initial diabetes drug choice was determined; drugs were classified as first generation (ie, approved before 2000) or second generation (ie, approved after 2000, including dipeptidyl peptidase 4 [DPP-4] inhibitors, glucagon-like peptide-1 [GLP-1] receptor agonists, and sodium-glucose cotransporter-2 [SGLT-2] inhibitors).

MAIN OUTCOMES AND MEASURES

The primary outcome was the between-practice variation in use of second-generation diabetes drugs between 2007 and 2015. Practices with use rates of second-generation diabetes drugs more than 1 SD above the mean were considered high prescribing, while those with use rates more than 1 SD below the mean were considered low prescribing.

RESULTS

Among 1 182 233 patients who initiated diabetes drug therapy at 42 977 practices between 2007 and 2015, 1 104 718 (93.4%) were prescribed a first-generation drug (mean [SD] age, 75.4 [6.7] years; 627 134 [56.8%] women) and 77 515 (6.6%) were prescribed a second-generation drug (mean [SD] age, 76.5 [7.2] years; 44 697 [57.7%] women). By December 2015, 22 457 practices (52.2%) had used DPP-4 inhibitors once, compared with 3593 practices (8.4%) that had used a GLP-1 receptor agonist once. Furthermore, 17 452 practices (40.6%) were using DPP-4 inhibitors in 10% of eligible patients, while 1286 practices (3.0%) were using GLP-1 receptor agonists in 10% of eligible patients, and SGLT-2 inhibitors, available after March 2013, were used at least once by 1716 practices (4.0%) and used in 10% of eligible patients by 872 practices (2.0%) by December 2015. According to Poisson random-effect regression models, beneficiaries in high-prescribing practices were more than 3-fold more likely to receive DPP-4 inhibitors (relative risk, 3.55 [95% CI, 3.42-3.68]), 24-fold more likely to receive GLP-1 receptor agonists (relative risk, 24.06 [95% CI, 14.14-40.94]) and 60-fold more likely to receive SGLT-2 inhibitors (relative risk, 60.41 [95% CI, 15.99-228.22]) compared with beneficiaries in low-prescribing practices.

CONCLUSIONS AND RELEVANCE

These findings suggest that there was substantial between-practice variation in the use of second-generation diabetes drugs between 2007 and 2015, with a concentration of use among a few prescribers and practices responsible for much of the early diffusion.

Comparison of vildagliptin and sitagliptin in patients with type 2 diabetes and severe renal impairment: a randomised clinical trial

AIMS/HYPOTHESIS

There are limited data comparing dipeptidyl peptidase-4 (DPP-4) inhibitors directly. We compared the safety and efficacy of vildagliptin and sitagliptin in patients with type 2 diabetes and severe renal impairment (RI).

METHODS

This study was a parallel-arm, randomised, multicentre, double-blind, 24 week study conducted in 87 centres across Brazil and the USA. Patients with type 2 diabetes, either drug naive or treated with any glucose-lowering agents, who had inadequate glycaemic control (HbA1c 6.5-10.0% [48-86 mmol/mol]) and an estimated GFR <30 ml min(-1) [1.73 m](-2) were randomised (via interactive voice response technology) to vildagliptin 50 mg once daily or sitagliptin 25 mg once daily. These doses are recommended in this patient population and considered maximally effective. Participants, investigators and the sponsor were blinded to group assignment. Efficacy endpoints included change in HbA1c and fasting plasma glucose (FPG) at all visits and the primary safety endpoint was assessment of treatment-emergent adverse events.

RESULTS

In total, 148 patients were randomised, 83 to vildagliptin and 65 to sitagliptin. All patients were analysed. After 24 weeks, the adjusted mean change in HbA1c was -0.54% (5.9 mmol/mol) from a baseline of 7.52% (59 mmol/mol) with vildagliptin and -0.56% (6.1 mmol/mol) from a baseline of 7.80% (62 mmol/mol) with sitagliptin (p = 0.874). FPG decreased by 0.47 ± 0.37 mmol/l with vildagliptin and increased by 0.16 ± 0.43 mmol/l with sitagliptin (p = 0.185). Both treatments were well tolerated with overall similar safety profiles.

CONCLUSIONS/INTERPRETATION

At their recommended doses for severe RI, vildagliptin (50 mg once daily) compared with sitagliptin (25 mg once daily) demonstrated similar efficacy and both drugs were well tolerated. This study provides further support for the use of DPP-4 inhibitors in patients with severe RI.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00616811 (completed)

FUNDING

This study was planned and conducted by Novartis.

Pharmacokinetics and clinical use of incretin-based therapies in patients with chronic kidney disease and type 2 diabetes

The prevalence of chronic kidney disease (CKD) of stages 3-5 (glomerular filtration rate [GFR] <60 mL/min) is about 25-30 % in patients with type 2 diabetes mellitus (T2DM). While most oral antidiabetic agents have limitations in patients with CKD, incretin-based therapies are increasingly used for the management of T2DM. This review analyses (1) the influence of CKD on the pharmacokinetics of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists; and (2) the efficacy/safety profile of these agents in clinical practice when prescribed in patients with both T2DM and CKD. Most DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin) are predominantly excreted by the kidneys. Thereby, pharmacokinetic studies showed that total exposure to the drug is increased in proportion to the decline of GFR, leading to recommendations for appropriate dose reductions according to the severity of CKD. In these conditions, clinical studies reported a good efficacy and safety profile in patients with CKD. In contrast, linagliptin is eliminated by a predominantly hepatobiliary route. As a pharmacokinetic study showed only minimal influence of decreased GFR on total exposure, no dose adjustment of linagliptin is required in the case of CKD. The experience with GLP-1 receptor agonists in patients with CKD is more limited. Exenatide is eliminated by renal mechanisms and should not be given in patients with severe CKD. Liraglutide is not eliminated by the kidney, but it should be used with caution because of the limited experience in patients with CKD. Only limited pharmacokinetic data are also available for lixisenatide, exenatide long-acting release (LAR) and other once-weekly GLP-1 receptor agonists in current development. Several case reports of acute renal failure have been described with GLP-1 receptor agonists, probably triggered by dehydration resulting from gastrointestinal adverse events. However, increasing GLP-1 may also exert favourable renal effects that could contribute to reducing the risk of diabetic nephropathy. In conclusion, the already large reassuring experience with DPP-4 inhibitors in patients with CKD offers new opportunities to the clinician, whereas more caution is required with GLP-1 receptor agonists because of the limited experience in this population.

Management of patients with type 2 diabetes and mild/moderate renal impairment: profile of linagliptin

Dipeptidyl-peptidase-IV (DPP-4) inhibitors are oral antidiabetic agents that can be administered as monotherapy in patients with contraindications to metformin or metformin intolerance, and in combination with other oral compounds and/or insulin. DPP-4 inhibitors act in a glucose-dependent manner and only increase insulin secretion and inhibit glucagon secretion under hyperglycemic conditions. Renal impairment is frequent in type 2 diabetes as a result of microvascular complications and diabetes treatment, and options in these patients are limited. Linagliptin is a DPP-4 inhibitor with a hepatobiliary route of elimination. In comparative studies, it was noninferior to metformin and sulfonylureas in lowering glycated hemoglobin (HbA_1c) and improving glycemic parameters. It can be used throughout all stages of renal impairment without dose adjustments. This review gives an overview of linagliptin in various stages of chronic kidney disease and has a focus on efficacy and safety parameters from clinical studies in patients with impaired renal function. These data are interpreted in the context of type 2 diabetes therapy in general.

[Significance of hemoglobin A1C in the management of diabetes in dialysis patients]

According to latest guidelines hemoglobin A1C plays a central role in the diagnosis of diabetes mellitus. It is well-known from epidemiologic studies that a high rate of diabetic patients enters into dialysis programs and these patients have an unfavourable mortality outcome. Based on surveys conducted in recent years in this patient group, hemoglobin A1C has an important role in assessing carbohydrate metabolism. However, there are several factors independent of blood glucose may affect hemoglobin A1C values both in hemodialysis and peritoneal dialysis patients. Hemodialysis disturbs hemoglobin A1c assessment because of an accelerated turnover of lost red blood cells. During peritoneal dialysis a considerable amount of glucose may be absorbed from the peritoneal solutions that may influence hemoglobin A1C level. Several alternative markers such as glycated albumin and fructosamine have been evaluated but they failed to have prognostic advantage. It has been concluded that among dialysis patients the hemoglobin A1C range between 6.5 and 8% is associated with the lowest mortality risk.

The effects of GLP-1 analogues, DPP-4 inhibitors and SGLT2 inhibitors on the renal system

Diabetic nephropathy (DN) affects an estimated 20%-40% of patients with type 2 diabetes mellitus (T2DM). Key modifiable risk factors for DN are albuminuria, anaemia, dyslipidaemia, hyperglycaemia and hypertension, together with lifestyle factors, such as smoking and obesity. Early detection and treatment of these risk factors can prevent DN or slow its progression, and may even induce remission in some patients. DN is generally preceded by albuminuria, which frequently remains elevated despite treatment in patients with T2DM. Optimal treatment and prevention of DN may require an early, intensive, multifactorial approach, tailored to simultaneously target all modifiable risk factors. Regular monitoring of renal function, including urinary albumin excretion, creatinine clearance and glomerular filtration rate, is critical for following any disease progression and making treatment adjustments. Dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels without additional risk of hypoglycaemia, and may also reduce albuminuria. Further investigation of the potential renal benefits of DPP-4 and SGLT2 inhibitors is underway.

Incretin therapies in the management of patients with type 2 diabetes mellitus and renal impairment

Renal impairment (RI) is common among patients with type 2 diabetes mellitus (T2DM), and these patients also experience an age-related decline in renal function. At the same time, treatment options are more limited and treatment is more complex, particularly in patients with moderate or severe RI due to contraindications, need for dose adjustment and/or regular monitoring, and side effects, such as fluid retention and hypoglycemia, which are a more serious concern in this patient population. Incretin therapies, consisting of the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and the oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are a promising new class of antihyperglycemic drugs. In the overall population, they improve glycemic control in a glucose-dependent manner and are not likely to cause hypoglycemia, representing a clear advantage in at-risk populations. Data regarding use of these agents in renally impaired patients have started to emerge, and the objective of this article is to provide an overview of the currently available data and the potential role of these novel agents in the management of patients with T2DM and RI. Data for the GLP-1 receptor agonists in patients with moderate or severe RI are still limited, with no trials dedicated to these populations currently published. In addition, their potential to cause gastrointestinal side effects may limit use in patients with RI due to the risk of dehydration and hypovolemia. The use of GLP-1 receptor agonists in patients with moderate or severe RI is therefore, at present, underlying caution and/or restrictions. On the other hand, data from specific trials in patients with moderate or severe RI are now becoming available for most of the DPP-4 inhibitors. These studies demonstrate good efficacy and tolerability of the DPP-4 inhibitors in patients with moderate or severe RI, thus opening a place for these therapies in the treatment of populations with T2DM and RI. Several of the DPP-4 inhibitors are already approved for use in patients with moderate or severe RI, including for those with end-stage renal disease. While discussing the advantages related to their common mechanism of action, this article also describes differences among the DPP-4 inhibitors (eg, related to their pharmacokinetic properties and the available clinical data). In conclusion, while initial data for these new therapies are promising, further experience is needed to fully assess the risk-benefit balance and clinical positioning of these agents in RI populations.

Poor glycemic control and decreased renal function are associated with increased intrarenal RAS activity in Type 2 diabetes mellitus

AIMS

The renin-angiotensin system (RAS) plays an important role in the pathogenesis of diabetic nephropathy. The aim of the present study was to investigate intrarenal RAS activity in patients with type 2 diabetes (T2DM).

METHODS

We measured urinary angiotensinogen, a reliable biomarker of intrarenal RAS activity, in 14 controls without T2DM, 25 T2DM patients without nephropathy, 11 chronic kidney disease (CKD) patients without T2DM and 46 CKD patients with T2DM. Associations between urinary angiotensinogen and clinical parameters were examined.

RESULTS

Compared with the controls, urinary [angiotensinogen:creatinine] were significantly higher in T2DM patients without nephropathy (4.70 ± 2.22 vs. 8.31 ± 5.27 μg/g, p=0.037). Age, hemoglobin A1c (HbA1c) and fasting plasma glucose correlated significantly and positively with the log{urinary [angiotensinogen:creatinine]} (r=0.632, p=0.007; r=0.405, p=0.027; r=0.583, p=0.003, respectively) in T2DM patients without nephropathy. In contrast, the urinary [angiotensinogen:creatinine] were not significantly different between CKD patients with and without T2DM (22.7 ± 27.8 vs. 33.5 ± 40.8 μg/g, p=0.740); although they were significantly higher when compared with non-CKD patients. In the CKD patients with T2DM systolic blood pressure, serum creatinine, estimated glomerular filtration rate and urinary [albumin:creatinine] correlated significantly with the log{urinary [angiotensinogen:creatinine]} (r=0.412, p=0.004; r=0.308, p=0.037; r=-0.382, p=0.001; r=0.648, p<0.001, p<0.001, respectively).

CONCLUSIONS

Our findings indicate that poor glycemic control is significantly associated with intrarenal RAS activity in T2DM patients without nephropathy, and that decreased renal function is significantly associated with intrarenal RAS activity in CKD patients with T2DM.

Direct action of endothelin-1 on podocytes promotes diabetic glomerulosclerosis

The endothelin system has emerged as a novel target for the treatment of diabetic nephropathy. Endothelin-1 promotes mesangial cell proliferation and sclerosis. However, no direct pathogenic effect of endothelin-1 on podocytes has been shown in vivo and endothelin-1 signaling in podocytes has not been investigated. This study investigated endothelin effects in podocytes during experimental diabetic nephropathy. Stimulation of primary mouse podocytes with endothelin-1 elicited rapid calcium transients mediated by endothelin type A receptors (ETARs) and endothelin type B receptors (ETBRs). We then generated mice with a podocyte-specific double deletion of ETAR and ETBR (NPHS2-Cre×Ednra(lox/lox)×Ednrb(lox/lox) [Pod-ETRKO]). In vitro, treatment with endothelin-1 increased total β-catenin and phospho-NF-κB expression in wild-type glomeruli, but this effect was attenuated in Pod-ETRKO glomeruli. After streptozotocin injection to induce diabetes, wild-type mice developed mild diabetic nephropathy with microalbuminuria, mesangial matrix expansion, glomerular basement membrane thickening, and podocyte loss, whereas Pod-ETRKO mice presented less albuminuria and were completely protected from glomerulosclerosis and podocyte loss, even when uninephrectomized. Moreover, glomeruli from normal and diabetic Pod-ETRKO mice expressed substantially less total β-catenin and phospho-NF-κB compared with glomeruli from counterpart wild-type mice. This evidence suggests that endothelin-1 drives development of glomerulosclerosis and podocyte loss through direct activation of endothelin receptors and NF-κB and β-catenin pathways in podocytes. Notably, both the expression and function of the ETBR subtype were found to be important. Furthermore, these results indicate that activation of the endothelin-1 pathways selectively in podocytes mediates pathophysiologic crosstalk that influences mesangial architecture and sclerosis.

Dynamic and dual effects of glycated hemoglobin on estimated glomerular filtration rate in type 2 diabetic outpatients

BACKGROUND

Diabetic nephropathy is the leading cause of incident end-stage renal disease in Taiwan. Previous studies on the consistent benefits of glycemic control in diabetic nephropathy focused primarily on delaying microalbuminuria. However, this effect on glomerular filtration rate (GFR) remains controversial. This study aims to establish a model that explains the controversial effects of glycated hemoglobin (HbA1C) on GFR.

METHODS

This retrospective cohort study followed subjects with type 2 diabetes mellitus, who were enrolled between June 2006 and December 2006, for 4 years. The effects of HbA1C on estimated GFR (eGFR) were examined both cross-sectionally and longitudinally. The dual effects of HbA1C on eGFR, and how renal function interferes with these effects, were investigated.

RESULTS

Of the 1,992 subjects enrolled, 1,699 completed the follow-up. HbA1C was positively correlated with eGFR in the cross-sectional study (β coefficient = 1.44, 95% CI: 0.71-2.17, p = 0.0001). In the longitudinal study, higher baseline HbA1C resulted in a greater decline in eGFR. The annual eGFR decline rates were -1.89, -1.29, and -0.68 ml/min/1.73 m(2)/year for baseline HbA1C >9, 7 to ≤9, and ≤7%, respectively. The eGFR value was simultaneously affected by concurrent (β coefficient = 0.78, 95% CI: 0.48-1.08, p < 0.0001) and preceding HbA1C (-0.52, -0.82 to -0.23, p < 0.0001). The positive effects of concurrent HbA1C on eGFR reached statistical significance at all stages of chronic kidney disease (CKD); however, the negative effects of preceding HbA1C only applied to CKD stages 3 and 4.

CONCLUSIONS

We developed a new model that demonstrates how preceding and concurrent HbA1C simultaneously affect eGFR in opposing ways. The dynamic effects varied among different CKD stages. The deterioration in eGFR at CKD stages 3 and 4 may be postponed by intensive glycemic control. Further prospective studies may be necessary to clarify the specific CKD stage(s) that will benefit from intensive glycemic control.

Safety and efficacy of linagliptin in type 2 diabetes patients with common renal and cardiovascular risk factors

Dipeptidyl-peptidase-IV (DPP-4) inhibitors have become an important orally active drug class for the treatment of type 2 diabetes as second-line therapy after metformin failure or as monotherapy or combination therapy with other drugs when metformin is not tolerated or contraindicated. DPP-4 inhibitors act mainly by increasing endogenous incretin hormone concentrations. They stimulate insulin secretion and inhibit glucagon secretion in a glucose-dependent manner with a significantly lower risk for hypoglycaemia than sulfonylureas. Furthermore, DPP-4 inhibitors are weight neutral. Linagliptin is a DPP-4 inhibitor that is eliminated by a hepatobiliary route, whereas the other DPP-4 inhibitors available today show a renal elimination. Therefore, it can be used in normal kidney function as well as in all stages of chronic kidney disease to stage 5 (glomerular filtration rate <15 ml/min/1.73 m(2)) without dose adjustments. Linagliptin was noninferior to metformin and sulfonylureas in clinical studies. In recent studies, it showed a superior safety profile over sulfonylurea treatment regarding hypoglycaemia and weight gain. More patients reached an HbA1c <7% without hypoglycaemia and weight gain with linagliptin compared with glimepiride. The safety profile with respect to a composite cardiovascular endpoint and stroke was also favourable for linagliptin, most likely due to a higher incidence of hypoglycaemia associated with glimepiride therapy and titration. This review gives an overview on the efficacy and safety of linagliptin in comparison with other antidiabetic drugs in type 2 diabetes patients with renal and cardiovascular risk factors as well as an outlook on the perspective for linagliptin in this patient population in the future.

Pharmacokinetic considerations for the treatment of diabetes in patients with chronic kidney disease

INTRODUCTION

People with chronic kidney disease (CKD) of stages 3 - 5 (creatinine clearance < 60 ml/min) represent ≈ 25% of patients with type 2 diabetes mellitus (T2DM), but the problem is underrecognized or neglected in clinical practice. However, most oral antidiabetic agents have limitations in case of renal impairment (RI), either because they require a dose adjustment or because they are contraindicated for safety reasons.

AREAS COVERED

The author performed an extensive literature search to analyze the influence of RI on the pharmacokinetics (PK) of glucose-lowering agents and the potential consequences for clinical practice.

EXPERT OPINION

As a result of PK interferences and for safety reasons, the daily dose should be reduced according to glomerular filtration rate (GFR) or even the drug is contraindicated in presence of severe CKD. This is the case for metformin (risk of lactic acidosis) and for many sulfonylureas (risk of hypoglycemia). At present, however, the exact GFR cutoff for metformin use is controversial. New antidiabetic agents are better tolerated in case of CKD, although clinical experience remains quite limited for most of them. The dose of DPP-4 inhibitors should be reduced (except for linagliptin), whereas both the efficacy and safety of SGLT2 inhibitors are questionable in presence of CKD.

Long-term efficacy and safety of linagliptin in patients with type 2 diabetes and severe renal impairment: a 1-year, randomized, double-blind, placebo-controlled study

OBJECTIVE

This placebo-controlled study assessed long-term efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in patients with type 2 diabetes and severe renal impairment (RI).

RESEARCH DESIGN AND METHODS

In this 1-year, double-blind study, 133 patients with type 2 diabetes (HbA(1c) 7.0-10.0%) and severe RI (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m(2)) at screening were randomized to linagliptin 5 mg (n = 68) or placebo (n = 65) once daily, added to existing background therapy. The primary efficacy end point was HbA(1c) change from baseline to week 12. Efficacy and safety end points were assessed after 1 year.

RESULTS

At week 12, adjusted mean HbA(1c) decreased by -0.76% with linagliptin and -0.15% with placebo (treatment difference, -0.60%; 95% CI -0.89 to -0.31; P < 0.0001). HbA(1c) improvements were sustained with linagliptin (-0.71%) over placebo (0.01%) at 1 year (treatment difference -0.72%, -1.03 to -0.41; P < 0.0001). Mean insulin doses decreased by -6.2 units with linagliptin and -0.3 units with placebo. Overall adverse event incidence was similar over 1 year (94.1 vs. 92.3%). Incidence of severe hypoglycemia with linagliptin and placebo was comparably low (three patients per group). Linagliptin and placebo had little effect on renal function (median change in eGFR, -0.8 vs. -2.2 mL/min/1.73 m(2)), and no drug-related renal failure occurred.

CONCLUSIONS

In patients with type 2 diabetes and severe RI, linagliptin provided clinically meaningful improvements in glycemic control with very low risk of severe hypoglycemia, stable body weight, and no cases of drug-related renal failure. The potential for linagliptin to spare insulin and provide long-term renal safety warrants further investigations.