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?

Sponsor

Aarhus University Hospital (Other)

Overall Status

Completed

CT.gov ID

NCT01452958

Collaborator

University of Aarhus (Other), Lundbeck Foundation (Other)

Enrollment

Location

Arms

Duration (Months)

0.8

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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:

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

Study protocols:

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

Condition or Disease	Intervention/Treatment	Phase
Inflammation Glucose Metabolism Disorders	Biological: TNF-alpha Biological: Endotoxin	N/A

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:

Direct local effects in muscle tissue (Study protocol 1)
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 Design

Study Type:

Interventional

Actual Enrollment :

24 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Participant, Care Provider)

Official Title:

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

Study Start Date :

Jun 1, 2010

Actual Primary Completion Date :

Jan 1, 2013

Actual Study Completion Date :

Jan 1, 2013

Arms and Interventions

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

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

Outcome Measures

Primary Outcome Measures

Acute metabolic effects of endotoxin and cytokine TNF-α (Study 2) [2 hours]
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.
Acute metabolic effects of endotoxin and cytokine TNF-α (Study 2) [4 hours]
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.
Acute metabolic effects of cytokine TNF-α (Study 1) [3 hours]
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.
Acute metabolic effects of cytokine TNF-α (Study 1) [3 hours]
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.

Secondary Outcome Measures

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