IGF-I and Free Fatty Acids Isn Glucose Metabolism in Acromegaly

NCT02084095 | Completed

• 1 other identifier: 28332
• Study Type: observational
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Background Glucose metabolism abnormalities are frequent in acromegaly. Insulin resistance (IR) correlates with the intensity of acromegaly and Insulin-like Growth factor-I (IGF-I) correlates better with IR than growth hormone (GH). Insulin secretion (IS) is significantly reduced in hyperglycemic acromegalics as compared with those with normal glucose levels. IS is independent of acromegaly intensity. The aim of this study is to show that in active acromegaly: 1) IGF-I does not cause IR but is just a better marker of acromegaly intensity than GH; 2) high GH levels induce IR through free fatty acids (FFA); 3) hyperglycemia is caused by a defficient IS on a background of IR. Methods Intensity of acromegaly will be assessed using serum levels of GH, IGF-I and IGF binding globulin-3. IR and IS will be assessd using an intravenous glucose tolerance test acording to Bergman model. FFA will be directly measured in plasma.

Conditions

Acromegaly

Outcome Measures

Primary Outcomes (3)

• The correlation coefficient between IGFBP-3 and insulin resistance assessed using Bergman model is non-inferior to the correlation coefficient between IGF-I and insulin resistance

  2 years

• Free fatty acids correlates significantly with insulin resistance assessed using Bergman model

  2 years

• Disposition index calculated using Bergman model is significantly reduced in subjects with glucose intolerance than in subjects with normal glucose tolerance

  2 years

Secondary Outcomes (5)

• GH, IGF-I and IGFBP-3 significantly correlates with insulin resistance calculated using Bergman model

  2 years

• GH, IGF-I and IGFBP-3 significantly correlates with free fatty acids

  2 years

• GH, IGF-I and IGFBP-3 does not correlate with insulin sensitivity calculated using Bergman model

  2 years

• GH, IGF-I and IGFBP-3 does not correlate with disposition index

  2 years

• Disposition index after reduction of acromegaly activity by various treatments

  3 months after surgery or start of medical treatment

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

The study will prospectively include patients with active acromegaly assessed in a tertiary center. All patients who meet inclusion and exclusion criteria will be invited consecutively to participate in the study until the proposed number of patients is reached.

You may qualify if:

• active acromegaly based on following criteria: minimum GH in oral glucose tolerance test (OGTT) over 1 ng/mL and serum IGF-I over upper limit of normal for age and sex
• age between 18 and 65 years old

You may not qualify if:

• more than one previous pituitary surgical intervention for acromegaly
• present medical treatment for acromegaly (somatostatin analogs, GH-receptor blockers, dopaminergic agonists)
• previous pituitary radiotherapy
• present medical treatment for hyperglycemia (oral antidiabetic drugs, insulin, etc)
• pituitary failure, treated or not
• medical or surgical conditions which, in the oppinion of the principal investigator, could impact on study results or patient's safety
• fasting blood glucose over 200 mg/dL or HbA1c over 8%.
• body mass index less than 20 or over 35 kg/mp

Sponsors & Collaborators

• Carol Davila University of Medicine and Pharmacy: lead

Study Sites (1)

"C. I. Parhon" Institute of Endocrinology

Bucharest, 011863, Romania

Location

MeSH Terms

Conditions

Acromegaly

Condition Hierarchy (Ancestors)

Bone Diseases, Endocrine; Bone Diseases; Musculoskeletal Diseases; Hyperpituitarism; Pituitary Diseases; Hypothalamic Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Endocrine System Diseases

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Lecturer, PhD

Study Record Dates

• First Submitted: March 7, 2014
• First Posted: March 11, 2014
• Study Start: March 1, 2014
• Primary Completion: March 1, 2019
• Study Completion: March 1, 2019
• Last Updated: August 21, 2019

Record last verified: 2019-08

Locations

RO (1)