Official Title: “Dietary Fatty Acids as Complementary Therapy for Thiazolidinediones in Type 2 Diabetes Mellitus”

The purpose of the study is to see how a dietary oil called conjugated linoleic acid, or CLA, might be useful in combination with a commonly-prescribed diabetes drug, rosiglitazone, also known as Avandia. When people start taking Avandia, even though their blood sugar levels get lower, it is common for them to gain some weight - around 4 to 8 pounds over the first year.

Some studies show that CLA can modestly reduce body weight and body fat. Our research idea is that taking CLA will lessen or prevent the weight gain that is seen with Avandia without interfering with the drug's effect on blood sugar.

Study Type: Interventional

Study Design: Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Placebo Control, Parallel Assignment, Safety/Efficacy Study

Study Primary Completion Date: January 2010

The long term goal of this research is to develop effective complementary strategies to aid in the management of type 2 diabetes (T2DM). The immediate objective of this study is to elucidate the extent to which conjugated linoleic acid (CLA) may act as a complementary therapy with thiazolidinediones (TZDs) for the management of T2DM. Our central hypothesis is that if CLA is concomitantly administered with a TZD for the treatment of T2DM, then body fat gain associated with TZD monotherapy for the management of T2DM will be inhibited. The rationale of this study is that using CLA to reduce body fat gain in people with T2DM who are using a TZD may improve efficacy and longevity of TZDs as effective pharmaceutical agents in the management of T2DM. We plan to test our central hypothesis and accomplish the overall objective of this research by pursuing the following three specific aims.

Specific Aim 1: Determine the ability of CLA to attenuate weight gain and accumulation of fat mass in people using TZD therapy for management of T2DM.

Specific Aim 2: Determine the ability of CLA to modulate insulin sensitivity when combined with TZD therapy in subjects with T2DM.

Specific Aim 3: Determine the safety and tolerability of CLA in combination with TZD therapy.

Intervention(s) in this Clinical Trial

• Drug: rosiglitazone
  • 4 mg/day, pill, from week -4 to week 32
• Dietary Supplement: conjugated linoleic acid (CLA)
  • 3.2 g/day,capsule, week 0 to week 32
• Dietary Supplement: conjugated linoleic acid (CLA)
  • 6.4 g/day, capsule, week 0 to week 32

Arms, Groups and Cohorts in this Clinical Trial

• Placebo Comparator: A
  • Avandia (Rosiglitazone) 4mg/day, 0 g CLA, 8 g Placebo oil (based on typical American diet)
• Experimental: B
  • 4mg/day rosiglitazone, 3.2 g CLA, 4.8 g placebo oil (based on typical American diet)
• Experimental: C
  • 4 mg/d rosiglitazone, 6.4 g CLA, 1.6 g placebo oil (based on typical American diet)

Primary Measures

• difference in change in body weight of the intervention groups
  • Time Frame: between baseline and week 32, or end of study
    Safety Issue?: No

Secondary Measures

• Change in fat mass
  • Time Frame: between baseline and week 32
    Safety Issue?: No
• change in lean mass
  • Time Frame: between baseline and week 32
    Safety Issue?: No
• change in insulin sensitivity
  • Time Frame: between week 0 and week 32
    Safety Issue?: No
• change in lipid profile (TChol, LDL, HDL, C-reactive protein)
  • Time Frame: week -4, -1, 0, 8, 16, 24, 31, 32
    Safety Issue?: Yes
• changes in adipocytokine profile (leptin, adiponectin, visfatin, and resistin)
  • Time Frame: week -4, -1, 0, 8,16, 24, 31, 32
    Safety Issue?: No
• changes in liver enzymes (ALT and AST)
  • Time Frame: week -4,-1, 0,8,16,24,31,32
    Safety Issue?: Yes
• edema
  • Time Frame: Week -4,-1,0,8,16,24,31,32
    Safety Issue?: Yes
• change in glucose control
  • Time Frame: week -1, 16, 31
    Safety Issue?: No
• Change in bone density, bone formation and resorption markers
  • Time Frame: Week -4, -1 and week 31
    Safety Issue?: No
• Change in C-Peptide
  • Time Frame: Week - 4, -1, 0, 1, 8, 16, 24, 31,32
    Safety Issue?: No
• Diabetes Coping behaviors and self - efficacy
  • Time Frame: Weeks -4, -1, 32
    Safety Issue?: No
• Chronic stress (as measured by questionnaire)
  • Time Frame: weeks -4 and 32
    Safety Issue?: No
• Appetite (as measured by appetite rating scale)
  • Time Frame: weeks -4, 0, 16, 32
    Safety Issue?: No
• EKG
  • Time Frame: weeks -4,16,32
    Safety Issue?: Yes
• BNP (brain type natriuretic peptide)
  • Time Frame: weeks -4 and 32
    Safety Issue?: Yes
• Energy balance (Physical Activity recalls, food records, indirect calorimetry)
  • Time Frame: weeks -1, 16, 31
    Safety Issue?: No
• Compliance (Fatty acid composition, pill counts)
  • Time Frame: Weeks -1, 0, 8, 16, 24, 31, 32
    Safety Issue?: No
• Nutrition knowledge
  • Time Frame: weeks -4, 0, 32
    Safety Issue?: No

Inclusion Criteria:

• diagnosis of type 2 diabetes mellitus
• HbA1c ≥ 6.5% and ≤ 9%
• Overweight or obese (BMI ≥ 25 kg/m2 and ≤ 40 kg/m2)
• Age ≥ 30 and ≤ 70 years (postmenopausal if female)
• Stable medical therapy for past 3 months
• Stable body weight (within ± 2 kg) for past 3 months
• Plans to remain in the Columbus, OH metropolitan area for at least 1 year

Exclusion Criteria:

• Substance abuse
• Current use of prescription or over-the-counter medications or supplements known to affect body composition
• Current use of prescription or over-the-counter medications or supplements known to interact with TZDs
• Current or previous diagnosis of CHF
• Current use of diuretic medications to control edema, or use within the past three months
• Self-report of claustrophobia
• Abnormal liver function
• Impaired cognitive function
• Current or previous diagnosis of renal disease
• Gastrointestinal diseases or disorders
• Current use of hormone therapies, or use within the past 3 months
• Has a pacemaker/defibrillator
• History of myocardial infarction, or need for PCI, or CABG
• Discontinuation of the study drug, Avandia

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 30 Years

Maximum Age for this Clinical Trial: 70 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: National Center for Complementary and Alternative Medicine (NCCAM)

Overall Clinical Trial Officials and Contacts

Martha A Belury, PHD, RD Principal Investigator The Ohio State University Department of Human Nutrition  

Overall Contact: Julia R Richardson, MS, RD 614-247-8235 richardson.429@osu.edu

Information obtained from ClinicalTrials.gov on September 05, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00607945

Study ID Number: R21 AT003520-01A2

ClinicalTrials.gov Identifier: NCT00607945

Health Authority: United States: Federal Government

The Ohio State University College of Education and Human Ecology Clinical Studies Website