Lipolytic Effects of GH in Hypopituitary Patients in Vivo

Summary

Growth hormone (GH) is essential for longitudinal bone growth and somatic development. These protein anabolic effects require sufficient nutritional supply. During fasting and caloric restriction GH predominantly promotes fat metabolism.

GH counteracts the effect of insulin in many tissues, of which insulin-stimulated glucose uptake in skeletal muscle has been most extensively studied. Substrate competition between elevated free fatty acids and glucose is suggested as a mechanism, and this hypothesis can be tested mechanistically by means of acipimox, which is a nicotinic acid that suppresses the fat metabolizing effects of GH.

The hypothesis is, that the suppressive effect of GH on insulin-stimulated glucose uptake in skeletal muscle is obviated by acipimox-induced inhibition of fat metabolism.

In order to investigate this, eight adult hypopituitary patients with documented GH-deficiency will be studied in the presence and absence of GH and acipimox, respectively, and biopsies from skeletal muscle and subcutaneous adipose tissue will be analyzed.

Knowledge of the effects of growth hormone and fat metabolism can in shot-sight as well as in long-sight have great importance for the understanding of growth disorders from overweight and type 2 diabetes to malnutrition and eating disorders.

Conditions

• Hypopituitarism
• Insulin Resistance
• Endocrine System Diseases
• Glucose Metabolism Disorders
• Metabolic Diseases
• Pituitary Diseases
• Brain Diseases

Interventions

DRUG

Acipimox

Acipimox is administered 4 times previous to and during the investigation day. Acipimox is used to suppress the lipolytic effect of GH.

DRUG

Placebo

Placebo is administered 4 times previous to and during the investigation day.

DRUG

GH substitution

GH substitution as usually

OTHER

GH pause

GH substitution pause two days prior to the experimental day

Sponsors & Collaborators

• University of Aarhus

  lead OTHER

Principal Investigators

• Jens Otto L Jørgensen, Professor · University Hospital of Aarhus

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Model

FACTORIAL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2016-02-10

Primary Completion

2016-12-22

Completion

2016-12-22

Countries

• Denmark

Study Locations