The Suppression of Toll Like Receptors by Insulin

This study will help us understand the possible beneficial effects of insulin in inflammation. Inflamamtion is considered to be the cause of atherosclerosis and heart disease.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance
• Intervention / Treatment: Drug: insulin infusion; Drug: Dextrose infusion; Drug: Saline Infusion

Detailed Description

Obesity and type 2 diabetes are major health problems in the United States and the world. Both conditions are characterized by increased inflammation and oxidative stress and are associated with increased risk of cardiovascular disease.

Our previous work shows that insulin exerts a prompt and powerful anti-inflammatory effect, on circulating blood cells and in plasma in healthy subjects and in critically ill patients.

Toll like receptors (TLRs) recognize bacterial and viral products like endotoxin and viruses and are major determinants of the inflammatory response against foreign pathogens. In view of the recent data showing that TLRs recognize a range of molecules and proteins that are not of pathogenic source like saturated lipids and that TLRs are involved in the pathogenesis of atherosclerosis which leads to cardiovascular disease and insulin resistance which leads to type 2 diabetes (DM) we hypothesized that insulin infusion suppresses TLRs expression.

Our preliminary data show that insulin infusion for 4 hours reduces the levels of many TLRs and thus might protect from inflammation induced conditions We therefore propose to investigate, in more detail, the effect of infusing different doses of insulin on TLRs mRNA and protein levels and its activity in obese and DM subjects over a longer infusion period and a larger number of subjects in circulating white blood cells and in fat tissue. Also we will be comparing the baseline levels of TLRs and TLRs related proteins as well as their modulation by insulin between normal, obese and DM subjects.

• Study Type: Interventional
• Enrollment (Actual): 42
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Buffalo, New York, United States, 14209
      • Millard Fillmore Gates Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

INCLUSION CRITERIA

Lean Group:

1. Age: 20 to 65 years of age inclusive
2. Sex: male or female
3. Normal fasting plasma glucose (65-100 mg/dl)
4. Normal BMI (20-25)

Obese Group:

1. Age: 20 to 65 years of age inclusive
2. Sex: male or female
3. Normal fasting plasma glucose (65-100 mg/dl)
4. BMI> 30

DM Group:

1. Type 2 Diabetes Mellitus
2. Age: 20 to 65 years of age inclusive
3. Sex: male or female
4. BMI >30
5. Hba1c < 8%
6. If on statins, angiotensin converting enzyme inhibitor, angiotensin receptor blocker or low dose aspirin, should be on a stable dose for one month.

EXCLUSION CRITERIA

1. Pregnancy
2. Congestive heart failure
3. Heart Rate <50 beats /minute
4. Sick Sinus Syndrome
5. Second or third degree heart block
6. Blood pressure <80 mm systolic or > 160/100 mmHg
7. Coronary event or procedure (myocardial infarction, unstable angina, coronary artery bypass surgery or coronary angioplasty) in the previous three months
8. Hepatic disease (transaminase > 3 times normal)
9. Renal impairment (serum creatinine > 1.5)
10. History of drug or alcohol abuse within past one year
11. Participation in any other concurrent clinical trial
12. Potassium (K+) values <3.5 meq/l to > 5.5 meq/l)
13. Any other life-threatening, non-cardiac disease
14. Use of an investigational agent or therapeutic regimen within 30 days of study
15. Type 2 diabetics on thiazolidinediones and/ or insulin
16. Subjects on steroids, NSAIDS or antioxidants
17. Patients taking exenatide or sitaglipin or loop diuretics
18. Anemia (Hemoglobin level less than 12gm/dl in females and 13gm/dl in males) 19)Allergy to lidocaine

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: obese subjects; obese (BMI >30Kg/m2) subjects infused with insulin, dextrose and saline in this specific sequence 1 week apart. Each infusion will continue for up to 24 hr	Drug: insulin infusion; insulin to be infused at 3.5 units/hour along with Dextrose 12.5% at a rate to achieve blood glucose levels between 80-120mg/dl; Other Names: Intravenous regular insulin infusion; Drug: Dextrose infusion; Dextrose 12.5% will be infused at a rate to maintain blood glucose level 80-120mg/dl; Other Names: Intravenous dextrose solution infusion; Drug: Saline Infusion; Saline will be infused at 100ml/hr; Other Names: normal saline infusion
Active Comparator: Normal weight subjects; Normal weight subjects infused with insulin, dextrose and saline in this specific sequence 1 week apart. Each infusion will continue for up to 24 hr	Drug: insulin infusion; insulin to be infused at 3.5 units/hour along with Dextrose 12.5% at a rate to achieve blood glucose levels between 80-120mg/dl; Other Names: Intravenous regular insulin infusion; Drug: Dextrose infusion; Dextrose 12.5% will be infused at a rate to maintain blood glucose level 80-120mg/dl; Other Names: Intravenous dextrose solution infusion; Drug: Saline Infusion; Saline will be infused at 100ml/hr; Other Names: normal saline infusion
Experimental: obese type 2 diabetes subjects; obese (BMI >30Kg/m2) subjects with type 2 diabetes infused with insulin, dextrose and saline in this specific sequence 1 week apart. Each infusion will continue for up to 24 hr	Drug: insulin infusion; insulin to be infused at 3.5 units/hour along with Dextrose 12.5% at a rate to achieve blood glucose levels between 80-120mg/dl; Other Names: Intravenous regular insulin infusion; Drug: Dextrose infusion; Dextrose 12.5% will be infused at a rate to maintain blood glucose level 80-120mg/dl; Other Names: Intravenous dextrose solution infusion; Drug: Saline Infusion; Saline will be infused at 100ml/hr; Other Names: normal saline infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Suppression of Toll Like Receptor (TLR) 2 mRNA by Insulin	percent change from baseline (0hrs) in TLR2 mRNA in mononuclear cells (MNC) following up to 24 hrs of 3.5U/hr insulin infusion (II) adjusted to the similar average change following up to 24hr infusion of dextrose (DI) and saline (SI) control groups. The correction is calculated as follows: Corrected percent change from baseline following II= change from baseline following II - (average change from baseline following DI and SI)*100. Changes from baseline are calculated as: (expression at 24hrs-expression at 0hr)/expression at 0hr.	24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in TLR4 mRNA in MNC	percent change from baseline (0hrs) in TLR4 mRNA in mononuclear cells (MNC) following up to 24 hrs of 3.5U/hr insulin infusion (II) adjusted to the same change following up to 24hr infusion of dextrose (DI) and saline (SI) control groups in this order. The correction is conducted as follows: Corrected percent change from baseline following II= change from baseline following II - (average change from baseline following DI and SI)*100. Changes from baseline are calculated as: (expression at 24hrs-expression at 0hr)/expression at 0hr. 2- For each PCR measurement of specific target gene, relative expression of 3 housekeeping genes (beta-actin, ubiquitin C and cyclophilin A) from the same cDNA is assessed, and normalization factor (based on the 3 genes) is calculated and entered into PCR software to automatically adjust/normalize target gene expression	24 hours
Change in CD14 Expression in MNC	percent change from baseline (0hrs) in CD14 mRNA in mononuclear cells (MNC) following up to 24 hrs of 3.5U/hr insulin infusion (II) adjusted to the similar average change following up to 24hr infusion of dextrose (DI) and saline (SI) control groups in this specific order. The correction is conducted as follows: Corrected percent change from baseline following II= change from baseline following II - (average change from baseline following DI and SI)*100. Changes from baseline are calculated as: (expression at 24hrs-expression at 0hr)/expression at 0hr. For each PCR measurement of specific target gene, relative expression of 3 housekeeping genes (beta-actin, ubiquitin C and cyclophilin A) from the same cDNA is assessed, and normalization factor (based on the 3 genes) is calculated and entered into PCR software to automatically adjust/normalize target gene expression.	24hrs
Fasting TLR2 mRNA Expression Levels in the 3 Cohorts	Comparison of TLR2 mRNA expression in MNC in fasting condition. Fasting TLR2 mRNA expression is measured using real-time PCR at baselines of the 3 visits (II, DI, SI visits) is averaged and reported as arbitrary units. For each PCR measurement of specific target gene, relative expression of 3 housekeeping genes (beta-actin, ubiquitin C and cyclophilin A) from the same cDNA is assessed, and normalization factor (based on the 3 genes) is calculated and entered into PCR software to automatically adjust/normalize target gene expression.	baseline/fasting

Collaborators and Investigators

• Sponsor: University at Buffalo
• Collaborators: American Diabetes Association
• Investigators: Principal Investigator: Paresh Dandona, MBBS, The Research foundation of SUNY at Buffalo

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2008
• Primary Completion (Actual): July 1, 2012
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: June 25, 2010
• First Submitted That Met QC Criteria: June 25, 2010
• First Posted (Estimated): June 28, 2010

Study Record Updates

• Last Update Posted (Actual): September 11, 2026
• Last Update Submitted That Met QC Criteria: August 18, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Hyperinsulinism; Nutritional and Metabolic Diseases; Insulin Resistance; Therapeutics; Drug Therapy; Surgical Equipment; Equipment and Supplies; Artificial Organs; Drug Delivery Systems; Infusion Pumps; Insulin Infusion Systems
• Other Study ID Numbers: 1934; 708CR13 (Other Grant/Funding Number: American Diabetes Association)