Glucose Tolerance in Acromegaly: The Influence of GH-excess on Glucose Metabolism and Insulin Resistance

Diabetes Clinical Trial

Official title: Observational, Cross-sectional, Longitudinal, Multi-center, Diagnostic Study to Evaluate the Influence of Acromegaly on Glucose Tolerance and to Evaluate the Changes of Impaired Glucose Tolerance During Standard Treatment of Acromegaly.

Status Completed

Clinical Trial Summary

Observational, Cross-sectional, longitudinal, multi-center, diagnostic study

Cross-sectional part of the study: To evaluate the influence of acromegaly on glucose tolerance

Longitudinal part of the study: To evaluate the changes of impaired glucose tolerance during standard treatment of acromegaly. Adult patients with established acromegaly

Cross-sectional part of the study: 150 patients

Longitudinal part of the study: 58 patients

Clinical Trial Description

TRIAL DESIGN Observational, cross-sectional (patients with normal glucose tolerance). longitudinal (patients with impaired glucose tolerance), multi-center, diagnostic study.

After checking the inclusion and exclusion criteria for the cross-sectional part of the study patients will be included for anamnesis according to Flow Chart Visit -1 (Screening Visit). After checking the glucose tolerance and the insulin resistance by HOMA-IR, the patients will be classified to the group with normal glucose tolerance defined as:

• fasting plasma glucose < 110 mg/dl and/or 2-hour plasma glucose after an OGTT < 140 mg/dl or to the group with impaired glucose tolerance defined as:

• fasting plasma glucose ≥ 110 mg/dl (IFG) and/or 2-hour plasma glucose after an OGTT ≥ 140 mg/dl (IGT). For the HOMA-IR the cut off is 1.5.

For patients with normal glucose tolerance the study will end after Screening Visit (V -1).

After patient recruitment of the cross-sectional part is completed an interim analysis is planned to verify that all criteria for the longitudinal study part are achieved. The longitudinal part should start not later than one year after the last patient was examined in the cross-sectional part. For patients with impaired glucose tolerance the inclusion and exclusion criteria for the longitudinal part of the study will be checked (Baseline, Visit 0). If a patient might be included into the longitudinal part of the study a 12 months observation with 4 further visits will follow.

Primary Objective and Endpoint

Cross-sectional part of the study:

To evaluate a correlation between IGF-I and glucose tolerance in acromegalic patients. The inclusion should be performed in 2 stratification groups.

Following two groups are defined:

1. 1/3 of patients with a controlled IGF-I (controlled means IGF-I in age and sex-related normal reference range.

2. 2/3 of patients with an uncontrolled IGF-I (uncontrolled means IGF-I not in age and sex related normal reference range.

Longitudinal part of the study:

To evaluate changes of impaired glucose tolerance by different standard treatment options in acromegaly.

For the analysis of the different treatment options patients will be stratified into 5 treatment groups. Decision will be made according to next planned therapeutic intervention at Screening Visit (V -1):

1. Surgery

2. Treatment with somatostatin analoga (with or without combination of dopamine agonists)

3. Treatment with growth hormone receptor antagonist

4. Treatment with somatostatin analoga in combination with growth hormone receptor antagonist

5. Others (e.g. radiation, dopamine agonist monotherapy, no intervention) ;

Study Design

Observational Model: Case-Only, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Acromegaly
• Diabetes
• Glucose Intolerance
• Impaired Glucose Tolerance
• Insulin Resistance

• NCT number: NCT00663000
• Study type: Observational
• Source: University Hospital Tuebingen
• Status: Completed
• Phase: N/A
• Start date: April 2008
• Completion date: December 2012