Rationale

Type 2 diabetes is typically characterised as a progressive irreversible condition. However, there is evidence that people with type 2 diabetes can achieve good glucose control or even remission through weight loss. Most studies that demonstrate this have used bariatric surgery or formula diets, which are rarely commissioned in the UK because of their high cost and reliance on specialists. Standard care for people with a new diagnosis of type 2 diabetes is structured diabetes education, which has low uptake and small, short term effects on weight and blood glucose.

The GLoW (Glucose Lowering through Weight management) trial evaluated whether a tailored behavioural weight management programme that can be delivered at scale achieves better glucose control and other health outcomes than education alone and whether any improvements in health and wellbeing justify the higher cost of the programme.

• Aims of the study
• Design
• Investigators
• Status
• Unit role
• Sponsors
• Partners and stakeholders
• Funding
• Data sharing

Aims of the study

Primary Objective

To evaluate the effect of a tailored diabetes education and behavioural weight management programme vs diabetes education on glycated haemoglobin (HbA1c) at 12 months in adults with a new diagnosis of type 2 diabetes mellitus.

Secondary Objectives

To evaluate the effect of diabetes education and behavioural weight management programme vs diabetes education on:

• body weight, body fat percentage, blood pressure, lipid profile, and modelled cardiovascular risk at 6 and 12 months
• probability of achieving clinically significant weight loss, good glycaemic control or diabetes remission at 6 and 12 months
• 6 and 12 month changes in diet and physical activity at 6 and 12 months
• psychosocial factors associated with successful weight control at 6 and 12 months
• To evaluate the within-trial cost-effectiveness of diabetes education and behavioural weight management programme vs diabetes education
  To assess the extent to which the two programmes reach the target population.

Qualitative Objectives

• To explore participant and practitioner experiences of the two programmes and the extent to which these programmes meet their needs.
• To clarify causal mechanisms, and identify contextual factors associated with variations in outcome.
• To identify barriers and facilitators to maintenance of weight management behaviours after treatment cessation.

Design

This was a pragmatic, randomised, single-blind, parallel group, two-arm, superiority trial. Participants were randomised to either the tailored diabetes education and behavioural weight management programme or to diabetes education (standard care) using a block randomisation with a 1:1 allocation stratified by gender and duration of diabetes. Participants were followed up at 6 months and 12 months

Primary outcome

• 12 month change from baseline in HbA_1c

Secondary outcomes

• 6 month change from baseline in HbA_1c
• 6 and 12 month changes from baseline in body weight, body fat percentage, systolic and diastolic blood pressure, total cholesterol, HDL cholesterol, and LDL cholesterol
• Probability of achieving good glycaemic control (HbA_1c <53mmol/mol) at 6 and 12 months
• Probability of achieving remission (HbA_1c <48mmol/mol and without medication for ≥2 months) at 6 and 12 months
• Probability of losing ≥5% and ≥10% of initial body weight at 6 and 12 months
• Modelled cardiovascular risk (UKPDS) at 12 months

Behavioural and Psychosocial Outcomes

• 6 and 12 month changes from baseline in objective physical activity (accelerometry), self-reported physical activity, an objective marker of fruit and vegetable intake (carotenoids), and self-reported dietary intake
• 6 and 12 months changes from baseline in dietary restraint, control over food cravings, emotional eating, self-regulatory skills, social support and diabetes related quality of life

Health Economic Outcomes

• Health-resource use over 12 months (Medical Notes, Registry Data, Resource Use Questionnaire)
• Self-reported out-of pocket costs and loss of productivity
• Quality-adjusted life-years (QALYs) based on HRQoL (EQ-5D-5L) and capability/wellbeing (ICECAP-A)
• Total and incremental costs from NHS and UK society perspectives; incremental net (monetary) benefit; value of information estimates.

Investigators

Principal investigators

Dr Amy Ahern – University of Cambridge

Professor Simon Griffin – University of Cambridge

Co-investigators

Dr Robbie Duschinsky – University of Cambridge

Professor Stephen Morris – University of Cambridge

Stephen Sharp – University of Cambridge

Professor Andrew Hill – University of Leeds

Dr Brett Doble – University of Oxford

Dr Carly Hughes – The Fakenham Medical Practice

Professor Alan Brennan – University of Sheffield

Jennifer Bostock – PPI Representative

Colin Lainson – NHS North Norfolk CCG

Status

Completed.

Unit role

Unit led study with responsibility for data.

Sponsors

The trial was jointly sponsored by the Cambridgeshire and Peterborough Clinical Commissioning Group and the University of Cambridge.

Partners and Stakeholders

University of Sheffield, University of Leeds, University of Oxford, Fakenham Medical Practice, NHS North Norfolk Clinical Commissioning Group, Cambridgeshire and Peterborough Clinical Commissioning Group, NIHR CRN Eastern.

Funding

This study was funded by the National Institute for Health Research (NIHR) Programme Grant for Applied Research (PGfAR) (Grant Reference Number: RP-PG-0216-20010). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care

Other Support

The tailored diabetes education and weight management programme was provided by WW® (formerly Weight Watchers) at no cost.

Data sharing

Please see our Data Sharing pages.