Endotoxin & Cytokines. Do Protein Loss and Metabolic Effects Depend on Central Nervous System (CNS) Activation of Stress Hormones or on Local Mechanisms in Muscle and Fat?

Endotoxin & Cytokines. Do Protein Loss and Metabolic Effects Depend on CNS Activation of Stress Hormones or on Local Mechanisms in Muscle and Fat?

Main objective :

The purpose of this study is to prove that the effects of bacterial endotoxin and cytokine TNF-α, on protein loss, fatty acid release, and glucose metabolism depend on two mechanisms:

1. Direct local effects in muscle tissue.
2. Activation of the hypothalamo-pituitary axis and a stress-hormone response

Study protocols:

1. Acute metabolic effects of TNF-α(Beromun, Boehringer-Ingelheim Germany) vs placebo perfused into the femoral artery of the leg in 8 healthy subjects.

2. Acute metabolic effects of

   • placebo(saline)
   • endotoxin(US standard reference E.Coli, endotoxin)
   • TNF-α(Beromun, Boehringer-Ingelheim Germany) given systemically
   • in 8 patients with hypopituitarism(to block stress hormone release) and in 8 healthy subjects all studied thrice.

Study Overview

• Status: Completed
• Conditions: Glucose Metabolism Disorders; Inflammation
• Intervention / Treatment: Biological: TNF-alpha; Biological: Endotoxin

Detailed Description

PURPOSE:

Knowledge about the effects of bacterial endotoxin and cytokines (and inflammation in general) in humans on protein, glucose and lipid metabolism and intracellular signalling in muscle and fat is sporadic and it is uncertain whether endotoxin and cytokines act directly in fat and muscle tissue or indirectly via central nervous system (CNS) mediated stress hormone release.

The investigators hypothesize that the metabolic effects of endotoxin and cytokine TNF-α, including protein loss, fatty acid release and decreased glucose uptake depend on two mechanisms:

1. Direct local effects in muscle tissue (Study protocol 1)
2. Activation of the hypothalamo-pituitary axis and generalized stress hormone response (Study protocol 2)

METHODOLOGY:

Study protocol 1:

Acute metabolic effects of TNF-α (Beromun, Boehringer-Ingelheim, Germany) versus placebo perfused into the femoral artery of the leg in 8 healthy subjects, studied once. Femoral vein sampling allows assessment of local metabolic events in the leg. The vessels were cannulated using the Seldinger technique. Each study comprises a 3 hour basal period and a 3 hour Hyperinsulinemic-Euglycemic Clamp. Muscle biopsies were obtained simultaneously from both lateral vastus muscles.

Study protocol 2:

Acute metabolic effects of (i)placebo (saline), (ii)endotoxin (US standard reference E.Coli, endotoxin) and (iii)TNF-α (Beromun, Boehringer-Ingelheim, Germany) given systemically intravenously (i.v.) in 8 patients with hypopituitarism (to block stress hormone release) and in 8 healthy subjects all studied thrice. Every study comprises a 4 hour basal period and a 2 hour Hyperinsulinemic-Euglycemic Clamp. Muscle and fat biopsies were obtained.

Study protocol 1 and Study protocol 2:

Assays: Mass spectrometry (15N-phenylalanine, 13C-urea), 3H-glucose, 3H-palmitate quantification, hormone and metabolite analysis, cytokine assays, intracellular signaling.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8000
    • Medical Department MEA, NBG, Aarhus University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria 1. group:

• Male
• 19 < BMI < 28
• 18 ≤ Age ≤ 50
• Healthy

Inclusion Criteria 2. group:

• Male
• 20 < BMI < 30
• Age > 25
• Healthy

Exclusion Criteria:

• Diseases
• Allergy

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: TNF-α; Beromun, Boehringer-Ingelheim, Germany	Biological: TNF-alpha; Study protocol 1: 6 ng/kg/h intraarterial Study protocol 2: 18 ng/kg/h intravenous; Other Names: Beromun, Boehringer-Ingelheim, Germany
Experimental: Endotoxin	Biological: Endotoxin; Study protocol 2:0,075 ng/kg/h intravenous; Other Names: E. coli endotoxin, US standard

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Acute metabolic effects of endotoxin and cytokine TNF-α (Study 2)	During a basal period. Acute metabolic effects: Glucose metabolism was quantified with raw arterio-venous differences and 3H3-Glucose tracer. Lactate was quantified with raw arterio-venous differences. Lipid metabolism was quantified with [9,10-3H]-Palmitate tracer and amino acid metabolism with 15N-Phenylalanine tracer and 13C-Urea tracer.	2 hours
Acute metabolic effects of endotoxin and cytokine TNF-α (Study 2)	During a hyperinsulinaemic euglycaemic clamp. Acute metabolic effects: Glucose metabolism was quantified with raw arterio-venous differences and 3H3-Glucose tracer. Lactate was quantified with raw arterio-venous differences. Lipid metabolism was quantified with [9,10-3H]-Palmitate tracer and amino acid metabolism with 15N-Phenylalanine tracer and 13C-Urea tracer.	4 hours
Acute metabolic effects of cytokine TNF-α (Study 1)	During a basal period. Acute metabolic effects: Glucose and lactate were quantified with raw arterio-venous differences; lipid metabolism was quantified with [9,10-3H]-palmitate and amino acid metabolism with 15N-phenylalanine.	3 hours
Acute metabolic effects of cytokine TNF-α (Study 1)	During a hyperinsulinaemic euglycaemic clamp. Acute metabolic effects: Glucose and lactate were quantified with raw arterio-venous differences; lipid metabolism was quantified with [9,10-3H]-palmitate and amino acid metabolism with 15N-phenylalanine.	3 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intracellular insulin signaling, growth hormone signalling and inflammatory signalling pathways.	Musle and fat biopsies during a basal period (120 min. from the beginning of a basal period)	120 min.
Intracellular insulin signaling, growth hormone signalling and inflammatory signalling pathways.	Musle and fat biopsies during a hyperinsulinaemic euglycaemic clamp (30 min. from the beginning of clamp)	30 min.

Collaborators and Investigators

• Sponsor: Aarhus University Hospital
• Collaborators: University of Aarhus; Lundbeck Foundation
• Investigators: Principal Investigator: Niels Møller, Professor, Aarhus University Hospital

Publications and helpful links

General Publications

• Bach E, Nielsen RR, Vendelbo MH, Moller AB, Jessen N, Buhl M, K-Hafstrom T, Holm L, Pedersen SB, Pilegaard H, Bienso RS, Jorgensen JO, Moller N. Direct effects of TNF-alpha on local fuel metabolism and cytokine levels in the placebo-controlled, bilaterally infused human leg: increased insulin sensitivity, increased net protein breakdown, and increased IL-6 release. Diabetes. 2013 Dec;62(12):4023-9. doi: 10.2337/db13-0138. Epub 2013 Jul 8.

Study record dates

Study Major Dates

• Study Start: June 1, 2010
• Primary Completion (Actual): January 1, 2013
• Study Completion (Actual): January 1, 2013

Study Registration Dates

• First Submitted: September 22, 2011
• First Submitted That Met QC Criteria: October 13, 2011
• First Posted (Estimate): October 17, 2011

Study Record Updates

• Last Update Posted (Estimate): January 30, 2013
• Last Update Submitted That Met QC Criteria: January 29, 2013
• Last Verified: January 1, 2013

More Information

Terms related to this study

• Keywords: Endotoxin; insulin resistance; LPS; metabolism; TNF-α
• Additional Relevant MeSH Terms: Pathologic Processes; Inflammation; Metabolic Diseases; Glucose Metabolism Disorders
• Other Study ID Numbers: 2010/0604