Study design
The Behavioural Lifestyle Intervention Study (BLIS) was a six-month randomized controlled trial with two parallel arms. Randomization occurred using computer-generated random number tables after assessments for inclusion/exclusion criteria. The patients were assigned to the intervention or control arm and were matched for gender. The patients in the intervention group then received a 6-month lifestyle programme, while the patients in the control group received standard care. Upon completion of the intervention, all of the patients were followed up at 1 year.
Setting and participants
The study was conducted at Rashid Centre for Diabetes and Research (RCDR), a tertiary care centre for diabetes in Ajman, UAE. Patients were referred to RCDR from primary health care centres in the Northern Emirates for specialized diabetes care. As part of the multidisciplinary care approach at RCRD, all of the patients were scheduled to meet a clinical dietitian 1–2 weeks after their initial consultation with the endocrinologist. All patients scheduled for the dietitian’s visit were assessed for the eligibility criteria. If eligible, patients were then informed about the study during their visit to the lifestyle clinic by the research personnel. To participate in the trial, the patients were required to meet the following inclusion criteria: a) 18–60 years old; b) clinical diagnosis of type 2 diabetes; c) HbA1c ≥ 7 %; d) body mass index (BMI) ≥ 25 (weight (Kg)/height (m2)); e) absence of a major physical disability that would restrict participation in moderate physical activity; f) absence of a serious heart condition, such as heart failure, heart attack, or stroke within the last 3 months; g) absence of proliferative retinopathy or kidney failure; and h) absence of current participation in a weight management or lifestyle programme. Of the 55 patients who were potentially eligible for the trial, 31 % (n = 17) were not eligible and 1 % (n = 3) refused to participate. Of the 35 randomized patients, 83 % completed the trial (n = 29) (Fig. 1). All patients were recruited between September and December 2013.
Intervention
All of the patients in the intervention group underwent a six-month lifestyle programme composed of 8 sessions, 4 individual sessions and 4 telephone calls, which were delivered by clinical dietitians (Fig. 2). CBT was the underpinning theory used to facilitate behavioural change. Evidence-based medical nutrition therapy was followed with all of the patients; however, the counselling method used in the intervention group was adapted to the main CBT strategies i.e., goal setting and self-monitoring. Goal setting was implemented by providing the patients with a goal chart at their baseline visit. This chart included SMART (smart, measurable, achievable, relevant and timed) goals for dietary changes, weight loss and physical activity. Carbohydrate intake was the main dietary factor targeted for change because the monitoring of carbohydrate intake is considered a key strategy in achieving glycaemic control [21]. Additionally, reducing carbohydrates intake is arguably more relevant to the Emirati community than reducing fat intake observed in other lifestyle interventions [10]. This is because, as observed in clinical practice, the Emirati diet is rich in carbohydrates sources such as rice, dates and juices. The weight loss targets were individualized based on the patients’ weight loss history and readiness for weight loss; these targets ranged from 5-7 %. The patients were provided with calorie-based diets (1200–1800 kcal) to help them achieve their weight loss targets. Physical activity targets based on the patients’ current levels of exercise were also provided. These targets were set so that the patients would achieve a minimum of 30 minutes of moderate physical activity 5 times per week by the end of the trial. During each individual session, the patient’s goal charts were reviewed, and new goals were set. Self-monitoring was encouraged through the maintenance of a diet diary, which was developed and provided at the initial assessment. In addition to individual sessions, the patients received 4 telephone calls to their mobile phones throughout the six-month trial. The telephone calls were conducted in accordance with a structured topic guide and included follow-up on the individual SMART goals, reinforcement of the use of the diet diaries, questions regarding the regularity of physical exercise, and the suggestion of solutions for problems encountered as the patients attempted to adhere to a healthy lifestyle. The intervention group also received structured educational materials developed specifically for the Emirati community regarding sources of carbohydrates and dietary fibre, physical activity, eating out, and healthy cooking methods. The patients in the control group received standard care i.e., 3 individual sessions scheduled at baseline, 1 month and 6 months. These patients received general dietary guideline handouts and calorie-based diets, were provided goals for lifestyle habits and were encouraged to employ self-monitoring. However, the control group was not supported with goal charts, diet diaries or structured nutrition education. All of the consultations for the intervention were delivered within the time allocated to meet the dietitian (Fig. 2).
Outcome measures
The trial was designed to be integrated into usual clinical practice; therefore, all of the outcomes measures were regular tests or measurements performed during routine assessments and were abstracted from the patients’ records. The trial’s primary outcome measure was HbA1c level. Secondary outcomes were weight, BMI, body composition analysis, lipid profile (serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG)), blood pressure, carbohydrate intake in grams, minutes of moderate physical exercise and medications for type 2 diabetes. The HbA1c and lipid profile (LDL, HDL, triglycerides, and total cholesterol) data were obtained using a Roche COBAS 6000 auto analyser (Mannheim, Germany). Systolic and diastolic blood pressures were measured in the right arm while the patient was seated and after he/she had rested for 10 minutes. The medications used by the patients were abstracted from their electronic records and included all oral anti-diabetic agents as well as insulin. Weight and height were measured using a SECA electronic scale (Hamburg, Germany). Body composition analysis (BCA), presented as fat mass (Kg), muscle mass (Kg) and water mass (Kg), was based on bioelectrical impedance using the InBody-230 analyser (Biospace, Dogok-dong, South Korea) under standard operating procedures. Carbohydrate intake was measured from the patients’ three-day food records using the American Dietetic Association food exchange system [22]. These values were then converted into grams of carbohydrates. The carbohydrate exchanges included cereals, fruits, dairy products, vegetables, legumes and other carbohydrates. Physical exercise, was self-reported as number of minutes per week of physical exercise with moderate intensity and was then averaged per day. Patients were given examples of moderate physical exercise commonly practiced by the Emirati community. Metabolic measures were performed as part of routine management in the diabetes clinic. The anthropometric, dietary and physical activity measures were assessed by the dietitian as part of the standard care assessments in the lifestyle clinic. For study participants, all of the measures were assessed at baseline, 3 months and 6 months. All of the enrolled participants were invited to attend a follow-up visit at 1 year.
Ethics, consent and permissions
This study was approved by the UAE Ministry of Health research ethics committee (reference number 032013–07). Additionally, all of the patients provided informed consent to participate in this study.
Statistical analysis
The sample size was calculated based on the assumption of observing a 10 % reduction in the mean HbA1c level, the primary outcome measure, at 6 months post-intervention. For a power of 80 %, the required sample size was estimated to be 50 patients. The data were presented as the mean ± standard deviation. The group means were compared at baseline using Student’s t-test, and one-way ANOVA was performed to compare the means between the groups at different time points. Bonferroni correction was used for all post hoc analyses to control for family-wise error; however, if the initial ANOVA was not significant, no further analysis was conducted. All of the tests were performed two-sided at a significance level of P ≤ 0.05. The data analysis was performed in accordance with the intention-to-treat analysis protocol.