Dialert, effects of a lifestyle intervention in Dutch and Turkish 1st degree relatives of persons with type 2 diabetes, a randomised controlled trial.

Rationale:
Prevention trials (e.g. Diabetes Prevention Program) in overweight persons with IGT have convincingly demonstrated that the risk of developing type 2 diabetes (T2DM) can significantly be reduced by modest weight reduction by means of lifestyle changes (diet, exercise). Family history (FHi) is a known risk factor for T2DM, and more so in the presence of overweight. Targeting preventive actions towards this group therefore is advocated and indeed prioritized in the National Action program for Diabetes but not yet practiced. Ethnic minorities warrant specific attention in this context. To date, no studies have tested the effects of offering lifestyle counselling specifically targeted at people with a FHi of diabetes from ethnic minorities. Persons from Turkish origin are known to be at increased risk for type 2 diabetes and cardiovascular disease but so far received little attention. This study is the first to compare the effects of group based lifestyle-counselling in Dutch and Turkish-Dutch 1st degree overweight relatives of patients with diabetes. Eligible participants will be recruited via their General Practitioner or outpatient clinic. The study is conducted in close collaboration with community health services in the Amsterdam region (GGD). Basic content and learning principles of the program are derived from existing behaviour change interventions in the field. Unique features of the program are the review of own family history of T2DM, a diabetes risk assessment and promoting family communication on diabetes prevention.


Objective:
The main objective of this study is to test and compare the effectiveness of a lifestyle-oriented intervention in Dutch and Turkish-Dutch 1st degree relatives of type 2 diabetes patients with overweight.


Study population:
First-degree relatives of type 2 diabetes patients, between age 29 and 55, and overweight. Intervention: The intervention comprises 2 interactive group sessions and one booster session, supplemented with a patient manual and newsletters. The follow-up program aims to sustain achieved behaviour changes. The wait-list control group receives the intervention 3 months after baseline. A culturally appropriate Turkish version of the program will be made available.

Main study endpoints:
The main endpoint is to achieve significant body weight loss at 3 months following the intervention. Secondary outcomes include anthropometric, medical, behavioural and psychological indices, along with process indicators.

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 at 3, 6 and 9 months following the intervention in both ethnic groups, resulting in reduced risk of developing type 2 diabetes and cardiovascular disease.

Baseline, 3, 6, 9 months (+ 12 months in the control group).

The intervention comprises 2 interactive group sessions, supplemented with a patient manual. To sustain achieved behaviour changes the follow-up program includes a booster session and 4 newsletters.