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

This study is currently recruiting participants. (see Contacts and Locations)
Verified August 2016 by Carol Davila University of Medicine and Pharmacy
Information provided by (Responsible Party):
Dan Niculescu, Carol Davila University of Medicine and Pharmacy Identifier:
First received: March 7, 2014
Last updated: August 2, 2016
Last verified: August 2016

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.


Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: The Role of Insulin-like Growth Factor-I (IGF-I) and Free Fatty Acids in Insulin Resistance, Insulin Secretion and Glucose Metabolism Abnormalities in Acromegaly

Resource links provided by NLM:

Further study details as provided by Carol Davila University of Medicine and Pharmacy:

Primary Outcome Measures:
  • 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 [ Time Frame: 2 years ]
  • Free fatty acids correlates significantly with insulin resistance assessed using Bergman model [ Time Frame: 2 years ]
  • Disposition index calculated using Bergman model is significantly reduced in subjects with glucose intolerance than in subjects with normal glucose tolerance [ Time Frame: 2 years ]

Secondary Outcome Measures:
  • GH, IGF-I and IGFBP-3 significantly correlates with insulin resistance calculated using Bergman model [ Time Frame: 2 years ]
  • GH, IGF-I and IGFBP-3 significantly correlates with free fatty acids [ Time Frame: 2 years ]
  • GH, IGF-I and IGFBP-3 does not correlate with insulin sensitivity calculated using Bergman model [ Time Frame: 2 years ]
  • GH, IGF-I and IGFBP-3 does not correlate with disposition index [ Time Frame: 2 years ]
  • Disposition index after reduction of acromegaly activity by various treatments [ Time Frame: 3 months after surgery or start of medical treatment ]

Estimated Enrollment: 20
Study Start Date: March 2014
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
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.

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02084095

Contact: Dan A Niculescu, MD

"C. I. Parhon" Institute of Endocrinology Recruiting
Bucharest, Romania, 011863
Sponsors and Collaborators
Carol Davila University of Medicine and Pharmacy
  More Information

Responsible Party: Dan Niculescu, Assistant Lecturer, PhD, Carol Davila University of Medicine and Pharmacy Identifier: NCT02084095     History of Changes
Other Study ID Numbers: 28332
Study First Received: March 7, 2014
Last Updated: August 2, 2016

Additional relevant MeSH terms:
Bone Diseases, Endocrine
Bone Diseases
Musculoskeletal Diseases
Pituitary Diseases
Hypothalamic Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Endocrine System Diseases processed this record on May 23, 2017