Title: Dietary Approaches to the Management Of type 2 Diabetes (DIAMOND) cluster randomised trial
Funder: Department of Health and Social Care

Abstract: Aim_x000D_ To show whether a low energy low carbohydrate food-based diet and support from practice nurses can help people with recently diagnosed type 2 diabetes achieve remission, meaning no need for diabetes medicines._x000D_ _x000D_ Background_x000D_ The DiRECT trial showed that nearly half of people with type 2 diabetes diagnosed in the last six years had remission of diabetes following an intensive weight loss programme in which participants stopped eating their normal food and ate specially formulated “total diet replacements”. However, total diet replacements do not appeal to all._x000D_ _x000D_ We developed the DIAMOND programme using “real food”, supporting patient self-management to reduce the demand on practitioner time so it is realistic for the NHS. We tested this in a “feasibility trial”, which showed we could recruit people who followed the programme with nurses delivering the programme as intended. Our initial results showed 10kg weight loss and two thirds had blood glucose in the non-diabetic range at three months. We will show whether this can be maintained._x000D_ _x000D_ Design and methods_x000D_ We will use similar processes as in the feasibility trial which recruited faster than planned. In this trial, we will recruit practices nationally, aiming to include 508 people who are socially representative of the UK population. We will ask practices to write to people with diabetes who are overweight and meet the study criteria. Interested persons will telephone the trial team for more details. If the person appears eligible, s/he will see a nurse at the local practice who will confirm consent and then measure height, weight, blood pressure, and a blood test for blood glucose control and cholesterol._x000D_ _x000D_ We will decide at random if practices will provide usual care for diabetes or offer the DIAMOND programme. Participants in practices offering the programme will be invited to see the nurse seven times over 6 months._x000D_ At 1 year, we will repeat the baseline measures. The main outcome is whether people have achieved remission- blood glucose below the diabetes level and off medication. Thereafter, we will assess whether people have diabetes through the National Diabetes Audit._x000D_ _x000D_ Patient & public involvement_x000D_ Diabetes UK working with people with diabetes (PWD) identified the role of behavioural and dietary interventions in reversing diabetes, the effectiveness of lifestyle changes, and the role of carbohydrates in managing diabetes as three of the top ten research priorities. In developing the DIAMOND programme, we convened discussion groups with PWD of different ages, genders, and cultural and ethnic backgrounds. People wanted to eat ‘real food’ and clear guidance on what they can and can’t eat. They suggested ways to make it easier follow: what to look for on food labels or increasing motivation by monitoring blood glucose. They helped improve and tailor our materials. One PPIE panel member, Derek Jerome, joined the study team and helped decide what outcomes to measure, developed our plain English summary and will co-manage the study._x000D_ _x000D_ Dissemination_x000D_ We will disseminate to people living with diabetes, health professionals and policy makers. We will also communicate directly to academic audiences and our public members will keep the patient voice at the heart of follow-on research. We have a track record of active dissemination (see https://www.phc.ox.ac.uk/research/research-themes/health-behaviours-theme/research/bwel-brief-intervention-on-weight-loss-trial.

Lay abstract: Research question_x000D_ Does a practice-nurse delivered behavioural support programme designed to motivate and enable people with type 2 diabetes (T2D) and overweight to follow a low energy low carbohydrate diet lead to greater remission from diabetes than usual care?_x000D_ _x000D_ Background_x000D_ Substantial weight loss achieved through a total diet replacement programme can induce remission of type 2 diabetes, but such programmes may not appeal to all. Our feasibility trial showed that a food-based programme with similar energy content (800-1000kcal/day), based on a low carbohydrate diet passed all feasibility criteria. Participants with type 2 diabetes lost 9.5kg and reduced HbA1c by 16mmol/mol at three months, with substantial reductions in blood pressure._x000D_ _x000D_ Aims and objectives_x000D_ The aim is to assess whether a low energy low carbohydrate diet and behavioural support from practice nurses is more likely to lead to remission compared with usual care in people with T2D diagnosed in the last six years._x000D_ The objectives are to assess the impact on:_x000D_ • Diabetes remission_x000D_ • glycaemic control_x000D_ • cardiovascular risk _x000D_ • weight _x000D_ • quality of life (QoL)_x000D_ • diet quality _x000D_ • cost-effectiveness over the lifetime and return on investment in the short-term._x000D_ at one year with follow-up thereafter of diabetes status, weight, glycaemic control and cardiovascular risk through the National Diabetes Audit/NHS Digital. We will also assess equity of programme uptake and the impact on these outcome measures of population characteristics including socioeconomic status and ethnicity._x000D_ _x000D_ Methods_x000D_ 56 practices will be recruited nationally to be socially representative of the UK (including traditionally underserved regions and populations and in particular ensuring diversity of ethnicity in invited populations) and randomised to give the DIAMOND programme or usual care. Nurses offering the DIAMOND programme will provide two hours of support over seven appointments over six months plus comprehensive resources, co-developed by people with diabetes. 508 participants will be enrolled, half receiving the intervention, half usual care. We will estimate cost-effectiveness from a healthcare perspective over several time horizons using an existing diabetes microsimulation model. _x000D_ _x000D_ Timelines for delivery_x000D_ The study will recruit participants over 14 months for a baseline follow-up assessment of weight and HbA1c at 6 months and all outcome measures at 12 months. The project takes 39 months, allowing time for study set-up, analsysis, and dissemination._x000D_ _x000D_ Anticipated impact and dissemination_x000D_ NHS England is commissioning several low energy diets in a 5000-patient pilot rollout. This programme could offer an alternative option for people who do not want to use formula products and would be much cheaper than current treatment programmes offered and if successful, could be incorporated into the national rollout of low energy diets to induce diabetes remission. The general approach of aiming to achieve remission in nearly all people with newly diagnosed type 2 diabetes is intended to become the first and best treatment option for people with newly diagnosed diabetes and this programme aims to be one of the treatment options. The modelling will estimate the long-term impact on health and healthcare expenditure and thus the cost-effectiveness of the intervention. We will work with Oxford Innovations to support long-term adoption by the NHS.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL;6.7 PHYSICAL
Health categories: METABOLIC AND ENDOCRINE