THE EFFICACY OF STRUCTURED LIFESTYLE INTERVENTION BASED ON TRANSCULTURAL DIABETES NUTRITION ALGORITHM WITH MOTIVATIONAL INTERVIEWING IN OVERWEIGHT AND OBESE TYPE 2 DIABETES MELLITUS PATIENTS

Abstract

Background: The Transcultural Diabetes Nutrition Algorithm (tDNA) was developed and validated by an international task force of independent diabetes and nutrition experts (Mechanick et al., 2012). The algorithm was culturally customised by local experts in Malaysia to suit our local populations (Zanariah et al., 2013). The tDNA aims at guiding primary care providers to recommend a healthy lifestyle intervention in a primary care setting based on initial risk evaluation. The tDNA recommends medical nutrition therapy (MNT), consisting of natural foods, a diabetes-specific formula, and increased physical activity, according to the algorithm based on initial body weight, glycated haemoglobin (HbA1c), exercise capacity and cardiovascular risk factors. Additionally, motivational interviewing counselling (MI) was included to facilitate positive behaviour changes in most lifestyle weight loss interventions. This study investigated the effectiveness of structured lifestyle intervention based on tDNA care with MI counselling compared to conventional counselling (CC) in overweight/obese T2DM patients in an outpatient clinical setting. Methodology: Two hundred and thirty overweight/obese T2DM patients, with HbA1c >7% and not treated with insulin, were randomised into tDNA care (n=115) and usual care (UC) (n=115). Patients in the tDNA group followed MNT consisting of a structured low calorie meal plan using natural foods, incorporation of diabetesii specific formulas as meal replacements, and exercise prescription of 150 min/week. Patients in the tDNA group also received either MI counselling (tDNA-MI) (n=58) or conventional counselling (tDNA-CC) (n=57). The UC group received standard dietary and exercise advice using conventional counselling. The main outcomes of the study were changes in weight and HbA1c. This study was carried for duration of 12 months. Results: At 6 months, body weight decreased significantly more in the tDNA-MI group (-6.9 ± 1.3 kg, p<0.001) than the tDNA-CC group (-5.3 ± 1.2 kg, p<0.001) and UC group (-0.8 ± 0.5 kg, p=1.000). Similarly, HbA1c decreased significantly more in tDNA-MI group (-1.1 ± 0.1%, p<0.001) than the tDNA-CC group (-0.5 ± 0.1%, p=0.001) and UC group (-0.2 ± 0.1%, p=0.260). Fasting plasma glucose decreased significantly in tDNA-MI group but remained unchanged in tDNA-CC and UC groups (tDNA-MI: -1.1 ± 0.3 mmol/L, p=0.011 vs. tDNA-CC: -0.6 ± 0.3 mmol/L, p=0.951 vs. UC: 0.1 ± 0.3 mmol/L, p=1.000). Similarly, waist circumference decreased in the tDNA-MI group but remained unchanged in tDNACC and UC groups (tDNA-MI: -4.0 ± 1.1 cm, p=0.002 vs. tDNA-CC: -2.7 ± 1.0 cm, p=0.064 vs. UC:-0.5 ± 0.5 cm, p=1.000). Percentage body fat decreased significantly in tDNA-MI group (-1.3 ± 0.4%, p=0.002) and tDNA-CC group (-1.5 ± 0.5%, p=0.017) but unchanged in the UC group (0.4 ± 0.3%, p=1.000). The systolic blood pressure decreased significantly in tDNA-MI and tDNA-CC groups but unchanged in the UC group (tDNA-MI: -9 ± 2 mmHg, p<0.001 vs. tDNA-CC: -9 ± 2 mmHg, p=0.001 vs. UC: -1 ± 2 mmHg, p=1.000). The diastolic blood pressure decreased significantly in tDNA-CC group (-6 ± 2 mmHg, p=0.008) but unchanged the tDNA-MI group (-3 ± 1 mmHg, p=0.566) and UC group (-1 ± 1 mmHg, iii p=1.000). Lipid profile was unchanged in the tDNA-MI and tDNA-CC groups, but the UC group had significant reduction in total cholesterol (-0.3 ± 0.1 mmol/L, p=0.001) and low-density lipoprotein cholesterol (-0.26 ± 0.07 mmol/L, p=0.005). Dietary energy, carbohydrate, protein and fat intake decreased significantly more in the tDNA-MI group (-574 ± 43 kcal, p<0.001; -69.5 ± 6.0 g, p<0001; -25.8 ± 2.4 g, p<0.001; and -21.9 ± 2.1 g, p<0.001, respectively) than tDNA-CC group (-458 ± 47 kcal, p<0.001; -56.4 ± 6.5 g, p<0.001; -18.5 ± 2.6 g, p<0.001; and -17.8 ± 2.3 g, p<0.001, respectively) and UC group (-171 ± 46 kcal, p=0.002; -25.1 ± 6.7 g, p=0.002; -3.6 ±1.9 g, p=0.586; and -6.1 ± 2.1 g, p=0.031, respectively). Exercise improved significantly in the tDNA-MI but unchanged in tDNA-CC and UC groups (tDNA-MI: 188 ± 16 min/week, p<0.001 vs. tDNA-CC: 149 ± 14 min/week, p=0.471 vs. UC: 106 ± 14 min/week, p=1.000). At 12 months, weight loss sustained significantly in the tDNA-MI group (-5.8 ± 1.3 kg, p<0.001) but not in the tDNACC group (-3.3 ± 1.2 kg, p=0.086) and UC group (0.5 ± 0.6 kg, p=1.000). Similarly, significant decrease in HbA1c retained in the tDNA-MI group (-0.5 ± 0.2%, p=0.006) but not in the tDNA-CC group (0.1 ± 0.2%, p=1.000) and UC group (0.02 ± 0.1%, p=1.000) at 12 months. Conclusion: Lifestyle intervention that includes structured MNT and physical activity following customised tDNA care was effective in achieving and sustaining weight loss, lowering of metabolic outcomes and dietary intake and improving exercise levels in this study. Motivational interviewing delivered by dietitian can enhance outcomes in patients with overweight/obesity with T2DM following intervention with structured MNT, such as the tDNA.