Rapid Effects Linagliptin on Monocyte Polarization and Endothelial Progenitor Cells in Type 2 Diabetes

Rapid Effects of the DPP-4 Inhibitor Linagliptin on Monocyte Polarization and Endothelial Progenitor Cells in Type 2 Diabetic Patients With and Without Chronic Renal Failure. A Randomized Cross-over Trial Versus Placebo

Diabetes mellitus is characterized by chronic low grade inflammation, which is worsened by the co-existence of renal failure.

One key aspect of chronic inflammatory diseases is the alteration in the polarization profile of circulating monocyte-macrophage cells.

Namely, monocytes-macrophages can exist in a pro-inflammatory (M1) polarized form or an anti-inflammatory (M2) polarized state. Alterations in the M1/M2 balance is thought to contribute to inflammation within atherosclerotic lesions and visceral adipose tissue which, in turn, can worsen cardiovascular disease and metabolic features in type 2 diabetic patients.

M1 and M2 are regulated by a complex interplay of soluble signaling molecules, many of which are substrate of the enzyme DPP-4 (dipeptidyl peptidase-4). Therefore, inhibition of DPP-4 can affect the M1/M2 polarization balance.

In this clinical trial, the investigators will test whether the DPP-4 inhibitor Linagliptin, compared to placebo, modifies the M1/M2 balance in type 2 diabetic patients with and without chronic renal failure.

In addition, we will test whether DPP-4 inhibition with Linagliptin acutely affects endothelial progenitor cells (EPCs), which are vasculoprotective cells implicated in the pathobiology of diabetic complications.

Study Overview

• Status: Completed
• Conditions: Type 2 Diabetes; Chronic Renal Failure
• Intervention / Treatment: Drug: Linagliptin; Drug: Placebo

Detailed Description

Type 2 diabetes is associated with chronic sterile low-grade inflammation, usually caused by hyperglycemia and associated biochemical abnormalities, as well as by overweight/obesity. The co-existence of chronic renal failure further exacerbates inflammation in diabetic patients, and this contributes to the exceedingly high morbidity and mortality of this category of patients. One key element of this type of inflammation is the pro- versus anti-inflammatory polarization of circulating monocytes and tissue macrophages. Diabetes indeed causes an imbalance of this polarization, in favour of the pro-inflammatory (M1) monocytes at the expenses of anti-inflammatory (M2) monocytes. Cells belonging to the monocyte/macrophage lineage are of great importance in diabetes pathophysiology, as they are involved in atherosclerosis and adipose tissue biology, both of which determine diabetes outcomes. It is recognized that M1/M2 polarization relies on the expression of chemokines/cytokines and their respective receptors. Interestingly, among non-incretin substrates of DPP-4 are several chemokines (e.g. MCP-1 and -2, RANTES and SDF-1a), which may regulate M1/M2 polarization. Linagliptin (terminal half-life >100 hours, and effective half-life for accumulation approximately 12 hours) can be safely used in type 2 diabetic patients with renal impairment without dose adjusting, because the drug is excreted >90% with feces and has a minor renal excretion. The possibility to modulate the M1/M2 inflammatory pathway with the DPP-4 inhibitor linagliptin entails a hitherto unappreciated opportunity for protecting diabetic patients with renal disease from the detrimental consequences of chronic inflammation on vascular and adipose tissue biology. We have set up a protocol to assess M1/M2 polarization of circulating monocyte/macrophage cells by flow cytometry. Our preliminary data indicate that diabetes is associated with an imbalance in M1/M2 polarization versus non diabetic controls, in favour of M1 cells in diabetic patients. Hyperglycemia per se may affect M1/M2 polarization and it is expected that any effect of linagliptin on monocytes can be detected as soon as DPP-4 inhibition reaches steady-state. Therefore, in order to provide a proof-of-concept for the effect of linagliptin on M1/M2 polarization and to avoid the confounding of improved glucose control, the time point of the study will be very short (4 days). Our preliminary data in cell cultures indicate that a few days of treatment with a stimulus is sufficient to modulate monocyte/macrophage polarization. This will provide valuable information on the direct effects of the drug on this inflammatory pathway.

Endothelial progenitor cells (EPCs) are vasculoprotective cells released from the bone marrow (BM) in response to ischemia, hypoxia and tissue injury. Once in the bloodstream, EPCs home to damaged tissues and help restoring a healthy and functional vasculature, by means of endothelial repair and angiogenesis. In steady-state conditions, CD34+KDR+ EPCs circulate in peripheral blood (PB) at very low levels and their release from the BM is coordinated by the sympathetic nervous system. It has been demonstrated that levels of EPC and generic CD34+ PC are predictors of future cardiovascular events, cardiovascular death and all-cause mortality. We have previously shown that Sitagliptin raised EPCs levels in 4 weeks. Herein, we aim to confirm those findings using Linagliptin, with a shorter time point.

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Phase 4

Contacts and Locations

Study Locations

• Italy
  • Padova, Italy, 35100
    • University Hospital Diabetes Outpatient Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Type 2 diabetes
• eGFR > 60 mL/min/1.73 mq (for the patients without renal failure)
• eGFR 10-60 mL/min/1.73 mq (for the patients with renal failure)

Exclusion Criteria:

• Type 1 diabetes
• Hypersensitivity to Linagliptin or excipients
• Intolerance to other DPP-4 inhibitors
• Terminal renal failure (eGFR < 10 mL/min/1.73 mq)
• Use of GLP-1 analogs or other DPP-4 inhibitors
• Recent (within 1 month) trauma or surgery or acute diseases
• Any acute or chronic inflammatory condition
• Immunosuppression or organ transplantation
• Pregnancy or lactation
• Inability to provide informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Linagliptin; Linagliptin 5 mg tablets daily for 4 days	Drug: Linagliptin; Linagliptin 5 mg tablets for 4 days; Other Names: Trajenta 5 mg
Placebo Comparator: Placebo; Placebo tablets 1 daily for 4 days	Drug: Placebo; Placebo tablets for 4 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
M1/M2 polarization balance	Evaluate whether 4-days Linagliptin treatment, compared to placebo, significantly reduces the M1/M2 ratio in type 2 diabetic patients. In this cross-over design trial, Linagliptin and placebo will be administered once daily for 4 consecutive days to 30 type 2 diabetic patients with or without renal failure with a 2 week washout period in between.	day 5

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cytokine and chemokine concentrations	Evaluate whether 4-days Linagliptin treatment, compared to placebo, significantly modifies the concentrations of selected cytokines and chemokines (MCP-1, RANTES, SDF-1a, IL-1, IL-6, TNF-a, IL-10, TGF-beta, CCL22, fraktalkine) in type 2 diabetic patients. In this cross-over design trial, Linagliptin and placebo will be administered once daily for 4 consecutive days to 30 type 2 diabetic patients with and without renal failure with a 2 week washout period in between. As the number of measures is high and there is no adjustment for multiple testing, this outcome is to be considered exploratory.	day 5
Endothelial progenitor cell levels	Evaluate whether 4-days Linagliptin treatment, compared to placebo, significantly modifies the levels of CD34+KDR+ EPCs (outcome added in course)	day 5

Collaborators and Investigators

• Sponsor: University of Padova
• Investigators: Study Chair: Angelo Avogaro, M.D. Ph.D., University of Padova; Principal Investigator: Gian Paolo Fadini, M.D., University of Padova

Publications and helpful links

General Publications

• Fadini GP, Bonora BM, Albiero M, Zaninotto M, Plebani M, Avogaro A. DPP-4 inhibition has no acute effect on BNP and its N-terminal pro-hormone measured by commercial immune-assays. A randomized cross-over trial in patients with type 2 diabetes. Cardiovasc Diabetol. 2017 Feb 10;16(1):22. doi: 10.1186/s12933-017-0507-9.
• Fadini GP, Bonora BM, Cappellari R, Menegazzo L, Vedovato M, Iori E, Marescotti MC, Albiero M, Avogaro A. Acute Effects of Linagliptin on Progenitor Cells, Monocyte Phenotypes, and Soluble Mediators in Type 2 Diabetes. J Clin Endocrinol Metab. 2016 Feb;101(2):748-56. doi: 10.1210/jc.2015-3716. Epub 2015 Dec 22.

Study record dates

Study Major Dates

• Study Start: September 1, 2012
• Primary Completion (Actual): December 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: June 3, 2012
• First Submitted That Met QC Criteria: June 9, 2012
• First Posted (Estimate): June 12, 2012

Study Record Updates

• Last Update Posted (Estimate): December 19, 2014
• Last Update Submitted That Met QC Criteria: December 18, 2014
• Last Verified: December 1, 2014

More Information

Terms related to this study

• Keywords: Inflammation; Diabetes; Kidney; Metabolism
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Kidney Diseases; Urologic Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Renal Insufficiency, Chronic; Kidney Failure, Chronic; Renal Insufficiency; Hypoglycemic Agents; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Protease Inhibitors; Incretins; Dipeptidyl-Peptidase IV Inhibitors; Linagliptin
• Other Study ID Numbers: 2588P