Metabolic Studies- Interactions Between GH and Insulin in GHDA

Metabolic Studies- Interactions Between GH and Insulin in GHDA. Insulin Resistance and GH Treatment: Dependence of Ambient GH Level Among Patients Treated With GH and Healthy Control Subjects

The purpose og this study is to investigate the effects of growth hormon on insulin signalling pathways and the temporal association between administration of GH and developing of insulin resistance.

Insulin resistance is a pathophysiological component of type 2 diabetes, obesity and elevated blood pressure. Overall they are syndromes with multifactorial ethology and partly unclarified pathophysiology. Insulin resistance also occur in more seldom diseases with a more unified pathogenesis. Growth hormone deficiency (GHD) in adults with hypopituitarism is an example of one of those seldom diseases. Prolonged GHD is associated with abdominal overweight, dyslipidemia and increased cardiovascular morbidity. Besides, GHD-patients have decreased insulin sensitivity presumably secondary to the altered body composition. Long term effects of GH-substitution improves insulin sensitivity but it is well-known that subcutaneous administration of GH acute worsen insulin sensitivity in both muscles- and liver-tissue. Recently it has been reported that insulin resistance in patients with type 2 diabetes is associated with the induction of a signal protein called suppressor of cytokine signalling (SOCS). It´s interesting that GH also induces a stimulation of SOCS.

Inclusion Criteria:

• Written consent before study start
• Growth Hormone substitution in stable dosis for at least 3 months prior to study start
• Other substitution in stable dosis for at least 3 months prior to study start

Exclusion Criteria:

• Medical treatment for diabetes
• Hypertension even with medical treatment
• BMI > 30
• Excessive alcohol abuse