A Lifestyle intervention in Dutch and Turkish Dutch 1st degree relatives of persons with type 2 diabetes. A pragmatic randomised controlled trial

Period: 2009-2013 
Funding: Dutch Diabetes Research Foundation
Research Institute: EMGO+
Contact: W.H. Heideman

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

Susceptibility to type 2 diabetes:

Perceptions and family communication regarding inheritance and primary prevention

Period: 2006-2010 
Funding: Diabetes Fonds Nederland (Dutch Diabetes Research Foundation), VUmc
Research Institute: EMGO+
Contact person: S.C.M. van Esch

 Type 2 diabetes (T2D) is best described as a multi factorial disease. Family history may serve as a good predictor of T2D risk since it reflects inherited genetic susceptibilities as well as shared environmental, cultural, and behavioral factors. 
We do know that family communication about genetic or 'familial' risk is influenced by pre-existing familial, social and cultural factors. If we understand more about how these factors influence communication within families with high risk on T2D, we might be able to identify effective strategies of using the family system and family communication in diabetes prevention addressing high risk family members.
The main focus in our project was to explore (family) illness perceptions and identify potential barriers in diabetes related family communication. Since T2D is highly prevalent in some ethnic minority groups, we explored possible cultural  influences as well.

Methods & Participants 
In a cross-sectional, observational study patients (n=546, response rate 41.6%) and their relatives (n=114, response rate 53.6%) filled in a questionnaire assessing demographic factors, causal illness beliefs (Illness Perception Questionnaire-Revised, IPQ-R), family history, risk perception, and diabetes-related family communication.
Patients' mean age is 63.8 (±11.7) and 50.2% is female. Almost 30% is from Surinamese-South Asian descent. Half of the relatives (51.3%) is younger than 45 year, 61.1% is female and 88.4% is a first degree family member.

Comparing causal illness beliefs of patients and relatives indicate that both groups generally have accurate risk perception concordant with multi factorial T2D etiology. Ethnic differences in illness beliefs and causal attributions are found. In general, risk perception is low in patients and relatives.
It appears that in most families (85%) talking about diabetes is not taboo; T2D is 'sometimes' or 'often' discussed. However, topics related to developing or preventing T2D onset are rarely discussed. In addition, T2D is more often a subject of conversation in Surinamese families.
The majority of patients seems willing to educate relatives about possible increased susceptibility and primary prevention, under the condition that there is good family contact and relatives show interest in T2D. Receptive relatives do not reject the idea of being informed via the family system; they seem appreciative of patients' information and consider it reliable.

Some findings in our study may suggest that promoting family risk communication might be a suitable strategy in diabetes prevention. However, we detected also factors that may complicate family awareness raising, such as low risk perception, troubled family relations and lack of relatives' interest. 
More detailed research is needed to explore the potential (cultural) effect of patients' illness beliefs and experienced diabetes burden on messages they spread out in their families.

S.C.M. van Esch, MSc