Clinical trial NCT00795275: Incretin Effect in People With Impaired Fasting Glucose
Official title: Exploring the Incretin Effect in People With IFG
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: pre-diabetes
isotopes
insulin secretion
insulin action
GLP-1
simple obesity
impaired fasting glucose
Lead sponsor: University of Colorado, Denver
Sponsor class: OTHER
First posted: 2008-11-21
Enrollment: 26
Sex: ALL
Minimum age (years): 45
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Regulation of endogenous glucose production (EGP) and insulin secretion are major actions of glucagon-like peptide-1 (GLP-1). Determining whether alterations in GLP-1 may contribute to abnormal EGP and insulin secretion in people with impaired fasting glucose (IFG) was the objective of the current study. The investigators hypothesized that defects in GLP-1 may explain the inappropriate basal EGP and diminished insulin secretion in IFG, and, furthermore, that by increasing circulating GLP-1 levels (using a new medicine called "sitagliptin") the investigators could reverse these defects.


Eligibility criteria: Inclusion Criteria:

* Healthy, sedentary, non-smokers, men and women 45-70 years old Subjects were placed into 1 of the 2 groups based on two 2-hour 75g oral glucose tolerance tests (2h OGTT), separated by one week: a control group with normal glucose tolerance (NGT; n=14; fasting glucose \<5.6 mmol/l and 2h OGTT \<7.8 mmol/l), or IFG (n=10; fasting glucose 5.6-6.9 mmol/l, and 2h OGTT \<7.8 mmol/l).

Exclusion Criteria:

* Subjects were excluded for: thyroid stimulating hormone \<50 or \>500 milliunits/L, fasting triglycerides \>10.3 mmol/l, creatinine \>130 μmol/l, elevated liver function tests (\>2 times normal), hematocrit \< 38%, or white blood cell count \<3.0 x 103. Use of medications for lipid and/or glucose lowering also excluded enrollees. Women may not have used hormone replacement therapy in the past 1 year. Smokers. BMI \<25 or \>40 kg/m2. Diabetes or impaired glucose tolerance.

Primary outcomes:
measure: Change in Endogenous Glucose Production
timeFrame: Baseline and 28 days
measure: Change in Insulin Secretion
timeFrame: Baseline and 28 days
Secondary outcomes:
measure: Insulin Secretion in Response to Oral vs. IV Glucose
timeFrame: Baseline
measure: Baseline and Change in Hormones, Substrates and Insulin Action: C-peptide
timeFrame: Baseline and 28 days
measure: Baseline and Change in Hormones, Substrates and Insulin Action: Glucagon
timeFrame: Baseline and 28 days
measure: Baseline and Change in Hormones, Substrates and Insulin Action: GLP-1
timeFrame: Baseline and 28 days
measure: Baseline and Change in Hormones, Substrates and Insulin Action: Lactate
timeFrame: Baseline and 28 days
measure: Baseline and Change in Hormones, Substrates and Insulin Action: FFA
timeFrame: Baseline and 28 days
measure: Baseline and Change in Hormones, Substrates and Insulin Action: Glycerol
timeFrame: Baseline and 28 days
Other outcomes:
Locations:
city: Aurora
country: United States
facility: University of Colorado Denver
state: Colorado
Study officials:
affiliation: University of Colorado, Denver
name: Leigh Perreault, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Perreault L, Man CD, Hunerdosse DM, Cobelli C, Bergman BC. Incretin action maintains insulin secretion, but not hepatic insulin action, in people with impaired fasting glucose. Diabetes Res Clin Pract. 2010 Oct;90(1):87-94. doi: 10.1016/j.diabres.2010.06.012. Epub 2010 Aug 13.