The Role of IntraNasal Insulin in Regulating HepaTic Lipid COntent in HUMANS

Summary

Non-alcoholic fatty liver disease (NAFLD) is a common human liver pathology, closely associated with the obesity pandemic and insulin resistance. In the insulin resistant state the liver remains sensitive to pro-lipogenic signals of insulin, which further promote lipid accumulation. Secretion of very-low-density-lipoproteins (VLDL), the main carriers of triglycerides (TG) in the plasma, is the principal pathway for the liver to mobilize and dispose of lipids. Thus, hepatic TG export must not be too low in order to prevent steatosis. Our preliminary data from animal experiments suggest that enhanced brain insulin signaling promotes hepatic VLDL secretion, and reduces lipid accumulation in the liver. It remains to be tested whether other insulin sensitive tissues, such as the myocardium or the skeletal muscle, are also affected. In humans, neuropeptides, including insulin, can be delivered to the brain via an intranasal (IN) route of administration, without causing relevant systemic side effects.

Therefore, we hypothesize that by enhancing brain insulin signaling using chronic IN insulin administration hepatic TG export increases and prohibits lipid accumulation in the liver and other insulin sensitive tissues, such as the myocardium and the skeletal muscle.

Conditions

• Healthy Subjects

Interventions

DRUG

Intranasal insulin administration

intranasal insulin (40 IE) Actrapid (100IE/mL); two 0.1 ml puffs per nostril) or placebo (insulin dilution buffer Novo Nordisk; two 0.1 ml puffs per nostril) four times a day (in total 160 IE Actrapid per day) before each main meal and before going to bed. 40 IE IN insulin enhances insulin concentration in the CSF without any changes in systemic insulin and glucose concentration, and no risk for hypoglycemia

DRUG

Insulin Dilution Buffer (Novo Nordisk)

intranasal insulin (40 IE) Actrapid (100IE/mL); two 0.1 ml puffs per nostril) or placebo (insulin dilution buffer Novo Nordisk; two 0.1 ml puffs per nostril) four times a day (in total 160 IE Actrapid per day) before each main meal and before going to bed. 40 IE IN insulin enhances insulin concentration in the CSF without any changes in systemic insulin and glucose concentration, and no risk for hypoglycemia

OTHER

1H magnetic resonance spectroscopy

1H MR spectroscopy and imaging will be performed on the on on the 3.0-T Tim Trio System (Siemens Erlangen Germany). MR Spectroscopy and imaging measurements will last no more than 90 minutes all together.

Sponsors & Collaborators

• Medical University of Vienna

  lead OTHER

Principal Investigators

• Michael Krebs, MD, Prof. · Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2014-09-30

Primary Completion

2016-07-31

Completion

2016-12-31

Countries

• Austria

Study Locations