Effect of High Monounsaturated Fat Diet on Glycemic Control and Cardiovascular Risk Factors in Type 2 Diabetes

Sponsor

University of Cincinnati (Other)

Overall Status

Completed

CT.gov ID

NCT00622960

Collaborator

American Diabetes Association (Other)

124

Enrollment

Location

Arms

Duration (Months)

3.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of this proposed randomized, controlled trial is to compare the effects of high monounsaturated fat diets and high carbohydrate diets on body weight, body composition, glycemic control, plasma lipids, and other cardiovascular risk factors over a period of one year. At present, no such studies of free-living subjects have been performed. The specific aims of the proposed project are to test the hypotheses that (1) a high monounsaturated fat diet will produce greater weight loss/body fat loss and more successful weight maintenance than a high carbohydrate diet and (2) a high monounsaturated fat diet will result in an improved lipid profile and better glycemic control than a high carbohydrate diet.

Condition or Disease	Intervention/Treatment	Phase
Overweight Obesity Type 2 Diabetes	Other: High-MUFA diet Other: High-CHO diet	Phase 1

Detailed Description

The incidence of type 2 diabetes has increased steadily over the last three decades. Although medical nutrition therapy is an integral component of diabetes management, nutrition recommendations for diabetes have often been based on clinical experience and expert consensus, rather than on carefully controlled clinical trials. The expert consensus on medical nutrition therapy is that carbohydrate and monounsaturated fat together should provide approximately 60-70% of total energy intake. This recommendation accommodates parties on both sides of a debate over what constitutes the optimal macronutrient composition of a diet for type 2 diabetic patients. On one side are proponents of high carbohydrate, low fat diets who contend that this regimen promotes the lowering of total- and LDL-cholesterol and is less calorically dense than diets containing a higher percentage of fat. On the other side are advocates of high monounsaturated fat, Mediterranean-type diets who cite data from short-term studies indicating that this approach decreases postprandial levels of plasma glucose, insulin, and triglycerides, and increases HDL-cholesterol more than isocaloric high carbohydrate diets. However, there is concern about the potential for high fat diets to increase energy intake and weight gain among free-living subjects. To make definitive, scientifically-based diet recommendations, it is essential that controlled long-term trials be conducted to demonstrate the health effects of specific percentages of monounsaturated fats and carbohydrates in the diets of persons with type 2 diabetes.

Study Design

Study Type:

Interventional

Actual Enrollment :

124 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

Comparison of High Monounsaturated Fat and High Carbohydrate Diets on Glycemic Control and Cardiovascular Risk Factors in Type 2 Diabetes

Study Start Date :

Apr 1, 2004

Actual Primary Completion Date :

Apr 1, 2007

Actual Study Completion Date :

Apr 1, 2007

Arms and Interventions

Arm	Intervention/Treatment
Experimental: High MUFA diet Those subjects assigned to a high monounsaturated fat diet	Other: High-MUFA diet The effects of high monounsaturated fat diet on body weight, body composition, lipid profile, and glycemic control.
Active Comparator: High CHO diet Those subjects assigned to a high carbohydrate diet	Other: High-CHO diet The effects of high carbohydrate diet on body weight, body composition, lipid profile, and glycemic control.

Arm

Intervention/Treatment

Experimental: High MUFA diet

Those subjects assigned to a high monounsaturated fat diet

Other: High-MUFA diet

The effects of high monounsaturated fat diet on body weight, body composition, lipid profile, and glycemic control.

Active Comparator: High CHO diet

Those subjects assigned to a high carbohydrate diet

Other: High-CHO diet

The effects of high carbohydrate diet on body weight, body composition, lipid profile, and glycemic control.

Outcome Measures

Primary Outcome Measures

body weight [prior to and after 4, 8, and 12 months of dieting]

Secondary Outcome Measures

body fat [prior to and after 4, 8, and 12 months of dieting]
blood pressure [prior to and after 4, 8, and 12 months of dieting]
blood lipid profile [prior to and after 4, 8, and 12 months of dieting]
glycemic control (glucose, insulin, and HbA1c) [prior to and after 4, 8, and 12 months of dieting]

Eligibility Criteria

Criteria

Ages Eligible for Study:

30 Years to 75 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

BMI of 27-40 kg/m2
30-75 years of age
Stable body weight for the preceding 6 months
Diagnosis of type 2 diabetes for at least 6 months prior to enrollment
HbA1c of 6.5 to 9.0
Treatment by diet or oral agents only

Exclusion Criteria:

Pregnancy or lactation
Active cardiac, pulmonary, renal, liver, or gastrointestinal disease
Untreated thyroid disease or hypertension
Hypertriglyceridemia with levels of TG > 500 mg/dl
Use of insulin
Use of specific medications that may alter lipid or glucose metabolism (other than the statins)
Use of medications that commonly cause significant alterations in body weight (e.g., corticosteroids).