Mediterranean diet and time-restricted eating as a cardiac rehabilitation approach for patients with coronary heart disease and pre-diabetes: the DIABEPIC-1 protocol of a feasibility trial

INTRODUCTION: Despite proven programmes, implementing lifestyle interventions for pre-diabetes and type 2 diabetes is challenging. Cardiac rehabilitation, provide a valuable opportunity to promote the adoption of healthy lifestyle behaviours for patients with atherosclerotic cardiovascular disease (ASCVD). However, only a limited number of studies have explored the potential for reversing the underlying causes of ASCVD in this setting. OBJECTIVES: The DIABEPIC1 study is an ongoing single-arm lifestyle clinical trial to assess the feasibility of an upgraded 6-month intensive cardiac rehabilitation programme combining an innovative diet assignment with exercise training to reverse newly onset pre-diabetes (glycated haemoglobin 5.7%–6.4%) to normal glucose concentrations in patients with coronary heart disease. METHODS AND ANALYSIS: 36 patients referred from the Montreal Heart Institute for cardiac rehabilitation, aged ≥40 years with a recent diagnosis of pre-diabetes in the last 6 months, will be offered to participate in the upgraded programme. Interventions will include four sessions of nutritional counselling on ultra-processed foods intake reduction and a moderate-carbohydrate (<40%) ad libitum Mediterranean diet coupled with 36 1-hour sessions of supervised exercise training (continuous and interval aerobic training, and resistance training) and educational intervention. Phase 2 will continue the same interventions adding 8:16 hour time-restricting eating (TRE) at least 5 days per week. During this second phase, exercise training will be performed with autonomy. The primary objectives will be to evaluate the recruitment rate, the completion rates at 3 and 6 months, and the compliance of participants. The secondary objectives will be to assess the proportion of prediabetic participants in remission of pre-diabetes at the programme’s end and to characterise the factors associated with remission. ETHICS AND DISSEMINATION: The DIABEPIC1 feasibility study is approved by the Research Ethics Board of the Montreal Heart Institute (Project Number ICM 2022-3005). Written informed consent will be obtained from each participant prior to inclusion. Results will be available through research articles and conferences. CONCLUSIONS: The DIABEPIC1 trial will examine the feasibility and effectiveness of an enhanced cardiac rehabilitation programme combining exercise training with an ultra-processed food reduction intervention, a Mediterranean diet, and TRE counselling to remit pre-diabetes to normal glucose concentrations. TRIAL REGISTRATION NUMBER: NCT05459987.