Effects of the Norfolk diabetes prevention lifestyle intervention (NDPS) on glycaemic control in screen-detected type 2 diabetes: a randomised controlled trial

BMC Med. 2021 Aug 19;19(1):183. doi: 10.1186/s12916-021-02053-x.

Abstract

Background: The purpose of this trial was to test if the Norfolk Diabetes Prevention Study (NDPS) lifestyle intervention, recently shown to reduce the incidence of type 2 diabetes in high-risk groups, also improved glycaemic control in people with newly diagnosed screen-detected type 2 diabetes.

Methods: We screened 12,778 participants at high risk of type 2 diabetes using a fasting plasma glucose and glycosylated haemoglobin (HbA1c). People with screen-detected type 2 diabetes were randomised in a parallel, three-arm, controlled trial with up to 46 months of follow-up, with a control arm (CON), a group-based lifestyle intervention of 6 core and up to 15 maintenance sessions (INT), or the same intervention with additional support from volunteers with type 2 diabetes trained to co-deliver the lifestyle intervention (INT-DPM). The pre-specified primary end point was mean HbA1c compared between groups at 12 months.

Results: We randomised 432 participants (CON 149; INT 142; INT-DPM 141) with a mean (SD) age of 63.5 (10.0) years, body mass index (BMI) of 32.4 (6.4) kg/m2, and HbA1c of 52.5 (10.2) mmol/mol. The primary outcome of mean HbA1c at 12 months (CON 48.5 (9.1) mmol/mol, INT 46.5 (8.1) mmol/mol, and INT-DPM 45.6 (6.0) mmol/mol) was significantly lower in the INT-DPM arm compared to CON (adjusted difference -2.57 mmol/mol; 95% CI -4.5, -0.6; p = 0.007) but not significantly different between the INT-DPM and INT arms (-0.55 mmol/mol; 95% CI -2.46, 1.35; p = 0.57), or INT vs CON arms (-2.14 mmol/mol; 95% CI -4.33, 0.05; p = 0.07). Subgroup analyses showed the intervention had greater effect in participants < 65 years old (difference in mean HbA1c compared to CON -4.76 mmol/mol; 95% CI -7.75, -1.78 mmol/mol) than in older participants (-0.46 mmol/mol; 95% CI -2.67, 1.75; interaction p = 0.02). This effect was most significant in the INT-DPM arm (-6.01 mmol/mol; 95% CI -9.56, -2.46 age < 65 years old and -0.22 mmol/mol; 95% CI -2.7, 2.25; aged > 65 years old; p = 0.007). The use of oral hypoglycaemic medication was associated with a significantly lower mean HbA1c but only within the INT-DPM arm compared to CON (-7.0 mmol/mol; 95% CI -11.5, -2.5; p = 0.003).

Conclusion: The NDPS lifestyle intervention significantly improved glycaemic control after 12 months in people with screen-detected type 2 diabetes when supported by trained peer mentors with type 2 diabetes, particularly those receiving oral hypoglycaemics and those under 65 years old. The effect size was modest, however, and not sustained at 24 months.

Trial registration: ISRCTN34805606 . Retrospectively registered 14.4.16.

Keywords: Diabetes Prevention Mentors; Glycaemic control; Lifestyle Intervention; Peer support; Screen detected; Type 2 diabetes.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Blood Glucose
  • Diabetes Mellitus, Type 2* / diagnosis
  • Diabetes Mellitus, Type 2* / prevention & control
  • Eye Proteins
  • Glycated Hemoglobin / analysis
  • Glycemic Control
  • Humans
  • Hypoglycemic Agents
  • Life Style
  • Middle Aged
  • Nerve Tissue Proteins
  • Treatment Outcome

Substances

  • Blood Glucose
  • Eye Proteins
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • NDP protein, human
  • Nerve Tissue Proteins

Associated data

  • ISRCTN/ISRCTN34805606