Effects of Growth Hormone Administration on Cardiovascular Risk in Cured Acromegalics With Growth Hormone Deficiency

• Status: Completed
• Trial end date: 2010-12-01
• Target enrollment: 0
• Participant gender: All

Summary

The purpose of the study is to evaluate the effects of growth hormone (GH) replacement in men and women with a history of acromegaly and who are now growth hormone deficient. We will compare them to persons with a history of acromegaly who have normal GH levels.

Acromegaly results when an area in the brain, called the pituitary, produces too much growth hormone. When an individual is cured of acromegaly, the growth hormone levels may be normal or low (that is GH deficiency). Growth hormone deficiency means the body no longer produces as much growth hormone because the pituitary/hypothalamic region was damaged by a tumor or by treatment received.

We will study the effects of growth hormone replacement on the health of the heart and blood vessels of GH deficient persons by looking to see if this therapy:

1. has effects on cardiovascular risk markers (special blood tests which indicate how healthy your heart and arteries are)

2. affects the stiffness of the arteries

3. affects your heart rate and the capacity of your heart to respond to changes in body position

4. has different effects depending on whether you are taking estrogen / testosterone.

We will assess these measures of health on one occasion in persons with cured acromegaly and normal GH levels and in persons with cured acromegaly who have GH deficiency and a contraindication to receiving GH. GH deficient individuals with no contraindication to receiving GH, will participate in the study for 12 months. Individuals with normal GH levels, or who are GH deficient and have a contraindication to receiving GH, will be asked to return for one more visit (without any interventions).

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Massachusetts General Hospital
• Treatments: Hormones

Criteria

Inclusion Criteria:

• Age 18-75

• History of acromegaly with biochemical cure documented with a normal oral glucose tolerance test (OGTT) and/or a non-elevated IGF-I without concurrent use of somatostatin analogs, dopamine agonists or GH receptor antagonists. Subjects will have been treated with medication, surgery, radiation, or a combination of these

• At the time of enrollment a minimum of 6 months must have elapsed since surgery.

• No malignancy on colonoscopy performed since the diagnosis of acromegaly

• GHD due to surgical or radiation treatment

• GHD will be defined as a peak plasma GH of less than 5 ng/ml in response to an insulin tolerance test or a GH-releasing hormone (GHRH) plus arginine stimulation test

• GHD will also be diagnosed if IGF-I levels are below 2 standard deviations for the age-sex normal range in a patient with at least two other documented anterior pituitary hormone deficiencies

Exclusion Criteria:

• Untreated thyroid or adrenal insufficiency. Subjects on replacement therapy must be stable for at least 3 months prior to entry into the study

• History of malignancy except for non-melanoma skin cancer

• Hemoglobin <11.0 gm/dl

• Uncontrolled hypertension

• Hepatic or renal disease (aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 3x upper limit of normal (ULN) or creatinine level >2.5 mg/dl)

• Congestive heart failure (New York Heart Association's classification system Class II-IV congestive heart failure (CHF) will be excluded)

• Unstable cardiovascular disease (coronary artery or cerebrovascular disease) or symptoms within one year prior to entry into the study

• Initiation or discontinuation of gonadal steroid therapy within 3 months of entry

• Diabetes mellitus, impaired fasting glucose, impaired glucose tolerance

• Pregnancy or nursing

• Active carpal tunnel syndrome

• Subjects who have received GH therapy within one year prior to entry into the study

• For female subjects age >40 a screening mammogram must have been obtained within one year prior to their baseline visit.

• Sensitivity to m-cresol