Period: 2009-2013
Funding: Dutch Diabetes Research Foundation
Research Institute: EMGO+
Contact: W.H. Heideman
website: www.dialert.nl
Family history (FHi) is a known risk factor for T2DM, and more so in the presence of overweight. Prevention trials (e.g. Diabetes Prevention Program) in overweight persons with IGT have demonstrated that the risk of developing type 2 diabetes (T2DM) can significantly be reduced by weight reduction. In the Netherlands persons from Turkish origin are known to be at increased risk for type 2 diabetes and cardiovascular disease, but so far received little attention.
The main objective of this study is to test and compare the effectiveness of a lifestyle-oriented intervention in Dutch and Dutch-Turkish 1st degree relatives of type 2 diabetes patients with overweight.
In this RCT, participants will be allocated to either the intervention or wait-list control group. Recruitment occurs via general practitioners and outpatient clinics in the Amsterdam region. Eligible are overweight persons from Dutch or Turkish origin with a first degree relative with type 2 diabetes, aged between 29 and 55 years.
The intervention aims to promote diabetes awareness and intrinsic motivation to change lifestyle. Two interactive group sessions and one booster session are offered. The follow-up program aims to sustain achieved behaviour changes. The wait-list control group receives the intervention 3 months after baseline. Basic content and learning principles of the program are derived from existing behaviour change interventions in the field with an emphasis on self-management. Unique features of the program are the review of own family history of T2DM, diabetes risk assessment and family communication on diabetes prevention. A culturally appropriate Turkish version of the program will be made available. The main endpoint is to achieve and maintain body weight loss. Secondary outcomes include anthropometric, medical and psychological indices, along with process indicators. Changes in outcomes are tested between intervention and control group at 3 months; effects over time are tested within and between both ethnic groups at 3, 6 and 9 months.
By means of t-tests and chi-square tests, baseline variables will be compared for the different groups. Linear and logistic regression models will be used to examine the effect of the intervention on each of the outcome measurements at 3 months cross-sectionally. Separate analysis of predictors will be performed to examine which participants benefit the most of the intervention.
To determine the effect of the intervention on weight loss and to follow individual change over the total follow-up time we will use a Generalized Estimating Equation (GEE) approach.
We hypothesize that the intervention will prove to be more effective than the control condition in achieving significant body weight loss at 3 months;
We expect to observe significant changes in metabolic, psychological and behavioural parameters 3, 6 and 9 months following the intervention in both ethnic groups, resulting in reduced risk of developing type 2 diabetes and cardiovascular disease.
W.H. Heideman, MSc