Clinical trial NCT00134290: The Effects of Calorie Restriction With or Without Metformin on Weight and Insulin Resistance
Official title: The Effects of Calorie Restriction - Whether or Not Calculated Based on BMR (Basic Metabolic Rate) - With or Without Metformin on Weight and Insulin Resistance of Obese Insulin Resistant Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Body Weight
Insulin Resistance
Lead sponsor: University Hospital, Ghent
Sponsor class: OTHER
First posted: 2005-08-24
Enrollment: 48
Sex: ALL
Minimum age (years): 20
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: This is a study to:

* Determine the difference between strong hypo-energetic "standard diet advice" and modest hypo-energetic "personal diet advice"; and
* Determine the influence of insulin-insensitivity on obesity and weight reduction by treating patients with metformin or placebo.

Detailed description: The aim of the present study was to determine what the difference is of a strong hypo-energetic "standard diet advice" and a modest hypo-energetic "personal diet advice" which was determined by the energy needs of a person as calculated with a combination of basal metabolic rate (BMR) and physical activity level (PAL) on weight loss and insulin sensitivity.

Secondly, this study wanted to determine what the influence is of insulin-insensitivity on obesity and weight reduction by treating the patients with metformin or placebo. The subjects were therefore randomised into two double blinded groups receiving either metformin (2 x 850 mg per day) or placebo in combination with a moderate energy restriction and a exercise regimen of 30 minutes per day for 1 year.

Treatment effects of both diets and the effect of metformin on weight reduction and insulin sensitivity were determined after a treatment period of 20 and 52 weeks.

Insulin sensitivity was quantified using the homeostasis model assessment (HOMA) and the OGTT. Body composition was determined with the bioelectrical impedance method.

Blood was also drawn for hormonal and biochemical analyses after 20 and 52 weeks of treatment. Furthermore, the patients had to fill out a 3-day food diary at baseline, after 20 weeks and after 52 weeks.

Eligibility criteria: Inclusion Criteria:

* 20-55 years of age
* Body mass index (BMI) equal to or greater than 30 kg/m²
* Insulin resistance as determined by oral glucose tolerance test (OGTT) and HOMA

Exclusion Criteria:

* Diabetes mellitus, kidney insufficiency, or hepatic insufficiency
* Hypogonadism with other etiology than overweight
* Pregnancy
* BMI equal to or greater than 40 kg/m²

Primary outcomes:
measure: Effect of diet on weight and insulin sensitivity/insulin resistance after 20 and 52 weeks of treatment
Secondary outcomes:
measure: Effect of metformin on weight and insulin resistance after 20 and 52 weeks of treatment
Other outcomes:
Locations:
city: Ghent
country: Belgium
facility: University Hospital Ghent
Study officials:
affiliation: University Hospital, Ghent
name: Mimi Giri, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: