OPTIFIT-Optimal Fiber Trial for Diabetes Prevention

Sponsor

German Institute of Human Nutrition (Other)

Overall Status

Completed

CT.gov ID

NCT01681173

Collaborator

Charite University, Berlin, Germany (Other), German Diabetes Foundation, Munich, Germany (Other), Ernst von Bergmann Hospital (Other), University Hospital Tuebingen (Other)

200

Enrollment

Locations

Arms

Duration (Months)

100

Patients Per Site

1.8

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

High intake of insoluble fiber is strongly associated with a reduced incidence of diabetes and cardiovascular events in prospective observation studies. Our primary objective is to compare a life style diabetes prevention program(PRAEDIAS) with and without added insoluble fibers in its effectiveness to prevent incident diabetes type 2 in high risk individuals with impaired glucose tolerance. Subjects with IGT not willing to participate in the intervention will be used as independent controls. Secondary aims are to identify mechanisms of action with regard to body composition, anti-inflammatory and metabolic effects of fibers. We propose a randomized, prospective intervention study. The results will be of general relevance for guidance of fiber intake in the population and will help the food industry to design healthy high fiber foods. Fiber can be added at low cost to numerous foods. Increased fiber intake may therefore provide a simple non-cognitive prevention strategy effective at the population level.

Condition or Disease	Intervention/Treatment	Phase
Diabetes Nutrition Disorders Obesity Overweight Metabolic Syndrome x Body Weight Glucose Metabolism Disorders Metabolic Diseases	Dietary Supplement: Fiber Dietary Supplement: Placebo	N/A

Detailed Description

The overall objective is to investigate whether insoluble fibers added to standard nutrition can reduce the progression of impairment of glucose metabolism in a high risk population with impaired glucose metabolism. Large prospective cohort studies clearly show that mainly insoluble cereal fiber from whole grains is associated with reduced risk of type 2 diabetes and cardiovascular disease. However, there is a lack of evidence from prospective intervention studies targeted to evaluate the potential of dietary fibers to reduce diabetes and cardiovascular disease as recently stated by the Cochrane Foundation. Dietary fiber intake is generally much lower than currently recommended, which may in part be related to side effects of whole grain nutrients and their gustatory properties. Intestinally uncomfortable effects are at least partly related to fermentation which is much less induced by insoluble non-fermentable fibers than by soluble fermentable fibers. The prospective demonstration of beneficial effects of insoluble fibers in preventing diabetes type 2 will allow detailed nutritional recommendations. This may serve to support the consumption of metabolically beneficial constituents of fiber-rich diets and help to increase fiber intake by high fiber natural nutrients or everyday nutrients enriched in insoluble natural fibers.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

200 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Care Provider, Investigator)

Primary Purpose:

Prevention

Official Title:

Investigation of the Effect of Insoluble Dietary Fiber on Carbohydrate and Lipid Metabolism and the Prevention of Diabetes Mellitus Type 2 in Subjects With Impaired Glucose Tolerance

Study Start Date :

May 1, 2010

Actual Primary Completion Date :

Dec 1, 2014

Actual Study Completion Date :

Dec 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Drink enriched in fibers 7,5g enriched fiber drinks, BID	Dietary Supplement: Fiber 200ml drinks enriched with 7,5g of fiber (90% insoluble fiber, 10% soluble fiber), BID, over 24 months
Experimental: Placebo drink Placebo drink, BID	Dietary Supplement: Placebo 200ml Placebo, BID, over 24 months

Arm

Intervention/Treatment

Experimental: Drink enriched in fibers

7,5g enriched fiber drinks, BID

Dietary Supplement: Fiber

200ml drinks enriched with 7,5g of fiber (90% insoluble fiber, 10% soluble fiber), BID, over 24 months

Experimental: Placebo drink

Placebo drink, BID

Dietary Supplement: Placebo

200ml Placebo, BID, over 24 months

Outcome Measures

Primary Outcome Measures

Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT) [0, 12, 24 months]
Change of the glucose metabolism (OGTT)

Secondary Outcome Measures

Change of insulin sensitivity [0, 12, 24 months]
Measurement by HOMA and OGIS from the OGTT
Change of insulin secretion [0, 12, 24 months]
Measurement by the OGTT
Expression of inflammatory markers in blood [0, 6, 12, 18, 24 months]
CRP, leukocytes, adipocytokines
Biometric data [0, 6, 12, 18, 24 months]
Nutritional impact of blood pressure, anthropometry (body weight and body composition)
Assessment of cognitive performance [0, 12, 24 months]
Development of indices for the prediction of fat mass [0, 12, 24 months]
Change of fat fraction in liver, abdominal and in the total body fat measuring by MRI/H1-spectroscopy
Determination of gene expression in adipose tissue [0, 12, 24 month]
Determination of inflammatory and other transcripts in sc adipose tissue in a fat biopsy.