title: Study Protocol: The Norfolk Diabetes Prevention Study [NDPS]: a 46 month multi - centre, randomised, controlled parallel group trial of a lifestyle intervention [with or without additional support from lay lifestyle mentors with Type 2 diabetes] to prevent transition to Type 2 diabetes in high risk groups with non - diabetic hyperglycaemia, or impaired fasting glucose.
abstract: This 7 year NIHR programme [2011-2018] tests the primary hypothesis that the NDPS diet and physical activity intervention will reduce the risk of transition to type 2 diabetes (T2DM) in groups at high risk of Type 2 diabetes. The NDPS programme recognizes the need to reduce intervention costs through group delivery and the use of lay mentors with T2DM, the realities of normal primary care, and the complexity of the current glycaemic categorisation of T2DM risk.
  
  
  
  NDPS identifies people at highest risk of T2DM on the databases of 135 general practices in the East of England for further screening with ab fasting plasma glucose and glycosylated haemoglobin [HbA1c]. Those with an elevated fasting plasma glucose [impaired fasting glucose or IFG] with or without an elevated HbA1c [non -diabetic hyperglycaemia; NDH] are randomised into three treatment arms: a control arm receiving no trial intervention, an arm receiving an intensive bespoke group-based diet and physical activity intervention, and an arm receiving the same intervention with enhanced support from people with T2DM trained as diabetes prevention mentors [DPM]. The primary end point is cumulative transition rates to T2DM between the two intervention groups, and between each intervention group and the control group at 46 months. Participants with screen detected T2DM are randomized into an equivalent prospective controlled trial with the same intervention and control arms with glycaemic control [HbA1c] at 46 months as the primary end point. Participants with NDH and a normal fasting plasma glucose are randomised into an equivalent prospective controlled intervention trial with follow up for 40 months. The intervention comprises six education sessions for the first 12 weeks and then up to 15 maintenance sessions until intervention end, all delivered in groups, with additional support from a DPM in one treatment arm.
  
  
  
  The NDPS programme reports in 2018 and will provide trial outcome data for a group delivered diabetes prevention intervention, supported by lay mentors with T2DM, with intervention in multiple at risk glycaemic categories, and that takes into account the realities of normal clinical practice.
  
  
  
  ISRCTN34805606 (Retrospectively registered 16.3.16).
authors.affiliation: Norfolk Diabetes Prevention Study, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK.|Directorate of Diabetes and Endocrinology, Elsie Bertram Diabetes Centre, Norfolk and Norwich University Hospital NHS Trust, Norwich, NR4 7UY, UK.
authors.forename: Melanie
authors.initials: M
authors.lastname: Pascale
authors.affiliation: Norfolk Diabetes Prevention Study, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK.|Directorate of Diabetes and Endocrinology, Elsie Bertram Diabetes Centre, Norfolk and Norwich University Hospital NHS Trust, Norwich, NR4 7UY, UK.
authors.forename: Nikki
authors.initials: N
authors.lastname: Murray
authors.affiliation: Department of Population Health and Primary Care, Norwich Medical School, University of East Anglia, Norwich, UK.
authors.forename: Max
authors.initials: M
authors.lastname: Bachmann
authors.affiliation: Health Economics Group, Norwich Medical School, University Of East Anglia, Norwich, UK.|Norwich Clinical Trials Unit, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.
authors.forename: Garry
authors.initials: G
authors.lastname: Barton
authors.affiliation: Norwich Clinical Trials Unit, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK.|Norwich Medical School, University of East Anglia, Norwich, UK.
authors.forename: Allan
authors.initials: A
authors.lastname: Clark
authors.affiliation: Department of Population Health and Primary Care, Norwich Medical School, University of East Anglia, Norwich, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Howe
authors.affiliation: University of Exeter Collaboration for Academic Primary Care (APEx), University of Exeter Medical School, Exeter, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Greaves
authors.affiliation: Norfolk Diabetes Prevention Study, Norfolk and Norwich University Hospital NHS Trust, Norwich, UK. mike.sampson@nnuh.nhs.uk.|Directorate of Diabetes and Endocrinology, Elsie Bertram Diabetes Centre, Norfolk and Norwich University Hospital NHS Trust, Norwich, NR4 7UY, UK. mike.sampson@nnuh.nhs.uk.
authors.forename: Mike
authors.identifier: 0000-0002-1433-2319
authors.initials: M
authors.lastname: Sampson
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D004032:Diet / Q000379:methods; D004739:England; D015444:Exercise; D005215:Fasting; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000628:therapy*; D008019:Life Style; D008297:Male; D000071252:Mentoring / Q000379:methods*; D008611:Mentors; D008875:Middle Aged; D011446:Prospective Studies; D012107:Research Design; D040242:Risk Reduction Behavior
chemical_list: D001786:Blood Glucose
keywords: Diabetes prevention; Impaired fasting glucose; Lay mentors; Lifestyle intervention; Non diabetic hyperglycaemia; Type 2 diabetes