Living Well with Diabetes: a randomized controlled trial of a telephone-delivered intervention for maintenance of weight loss, physical activity and glycaemic control in adults with type 2 diabetes

Background By 2025, it is estimated that approximately 1.8 million Australian adults (approximately 8.4% of the adult population) will have diabetes, with the majority having type 2 diabetes. Weight management via improved physical activity and diet is the cornerstone of type 2 diabetes management. However, the majority of weight loss trials in diabetes have evaluated short-term, intensive clinic-based interventions that, while producing short-term outcomes, have failed to address issues of maintenance and broad population reach. Telephone-delivered interventions have the potential to address these gaps. Methods/Design Using a two-arm randomised controlled design, this study will evaluate an 18-month, telephone-delivered, behavioural weight loss intervention focussing on physical activity, diet and behavioural therapy, versus usual care, with follow-up at 24 months. Three-hundred adult participants, aged 20-75 years, with type 2 diabetes, will be recruited from 10 general practices via electronic medical records search. The Social-Cognitive Theory driven intervention involves a six-month intensive phase (4 weekly calls and 11 fortnightly calls) and a 12-month maintenance phase (one call per month). Primary outcomes, assessed at 6, 18 and 24 months, are: weight loss, physical activity, and glycaemic control (HbA1c), with weight loss and physical activity also measured at 12 months. Incremental cost-effectiveness will also be examined. Study recruitment began in February 2009, with final data collection expected by February 2013. Discussion This is the first study to evaluate the telephone as the primary method of delivering a behavioural weight loss intervention in type 2 diabetes. The evaluation of maintenance outcomes (6 months following the end of intervention), the use of accelerometers to objectively measure physical activity, and the inclusion of a cost-effectiveness analysis will advance the science of broad reach approaches to weight control and health behaviour change, and will build the evidence base needed to advocate for the translation of this work into population health practice

Alterations of Left Ventricular Myocardial Characteristics Associated with Obesity

Background-Obesity is associated with heart failure, but an effect of weight, independent of comorbidities, on cardiac structure and function is not well established. We sought whether body mass index (BMI) and insulin levels were associated with subclinical myocardial disturbances. Methods and Results-Transthoracic echocardiography, myocardial Doppler-derived systolic (sm) and early diastolic velocity ( em), strain and strain rate imaging and tissue characterization with cyclic variation (CVIB), and calibrated integrated backscatter (cIB) were obtained in 109 overweight or obese subjects and 33 referents (BMI35) and the referent patients (

Effect of weight loss due to lifestyle intervention on subclinical cardiovascular dysfunction in obesity (body mass index >30 kg/m2) Y. Wong MB, BSa, M. Byrne PhDd, ’Moore-Sullivan MB, BSa, b, c, P. Hills PhDd, B. Prins MB, BS, PhDa, b, c and H. Marwick

Subclinical myocardial and vascular dysfunctions occur in subjects with obesity. We investigated whether these changes were reversible with weight loss due to lifestyle intervention. Quantitative assessment of myocardial and vascular functions was performed at baseline and after a minimum of 8 weeks of a lifestyle intervention program in 106 subjects with significant risk factors but no history of cardiovascular disease and normal ejection fractions. Myocardial function was assessed using strain rate, strain, regional myocardial systolic velocity, and diastolic velocity (e(m)). Myocardial reflectivity was assessed by calibrated integrated backscatter. Vascular function was assessed using brachial arterial reactivity and arterial compliance. Exercise capacity was measured by peak oxygen consumption per unit time (VO2). Weight loss (-4.5 +/- 2.0%) was achieved by 48 subjects, and 58 maintained or increased weight (+1 +/- 1.5%, p < 0.001). Compared with the stable weight group, the weight loss group showed significant improvement in brachial arterial reactivity (8.6 +/- 4.9% vs 6.7 +/- 4.9%, p < 0.05), e(m) (6.4 +/- 1.9 vs 5.5 +/- 1.9 cm/s, p < 0.01), and reflectivity (calibrated integrated backscatter, 18.3 +/- 4.9 vs 16.2 +/- 5.2 dB, p < 0.01). The magnitude of weight change correlated with changes in e(m) (r = 0.36) and calibrated integrated backscatter (r = 0.33). The change in e(m) correlated with peak VO2 (r = 0.38, p < 0.001) and was an independent predictor for peak VO2 even after adjustment for age and body mass index in a multivariate model (R-2 = 0.45, p < 0.001). Weight loss was not associated with a significant change in systolic parameters (regional myocardial systolic velocity, global strain, and strain rate) or arterial compliance. (c) 2006 Elsevier Inc. All rights reserved

Effect of 1-h moderate-intensity aerobic exercise on intramyocellular lipids in obese men before and after a lifestyle intervention

Intramyocellular lipids (IMCL) are depleted in response to an acute bout of exercise in lean endurance-trained individuals; however, it is unclear whether changes in IMCL content are also seen in response to acute and chronic exercise in obese individuals. We used magnetic resonance spectroscopy in 18 obese men and 5 normal-weight controls to assess IMCL content before and after an hour of cycling at the intensity corresponding with each participant's maximal whole-body rate of fat oxidation (Fat(max)). Fatmax was determined via indirect calorimetry during a graded exercise test on a cycle ergometer. The same outcome measures were reassessed in the obese group after a 16-week lifestyle intervention comprising dietary calorie restriction and exercise training. At baseline, IMCL content decreased in response to 1 h of cycling at Fatmax in controls (2.8 +/- 0.4 to 2.0 +/- 0.3 A.U., -39%, p = 0.02), but not in obese (5.4 +/- 2.1 vs. 5.2 +/- 2.2 A.U.,p = 0.42). The lifestyle intervention lead to weight loss (-10.0 +/- 5.4 kg, p < 0.001), improvements in maximal aerobic power (+5.2 +/- 3.4 mL/(kg.min)), maximal fat oxidation rate (+0.19 +/- 0.22 g/min), and a 29% decrease in homeostasis model assessment score (all p < 0.05). However, when the 1 h of cycling at Fatmax was repeated after the lifestyle intervention, there remained no observable change in IMCL (4.6 +/- 1.8 vs. 4.6 +/- 1.9 A.U., p = 0.92). In summary, there was no IMCL depletion in response to 1 h of cycling at moderate intensity either before or after the lifestyle intervention in obese men. An effective lifestyle intervention including moderate-intensity exercise training did not impact rate of utilisation of IMCL during acute exercise in obese men