Characterisation of type 2 diabetes subgroups at diagnosis: the COPERNICAN prospective observational cohort study protocol

Introduction Type 2 diabetes mellitus (T2DM) is a highly heterogeneous and complex metabolic disease harbouring different metabolic characteristics. Adequate characterisation of subjects is essential to allow the implementation of precision medicine for the prevention, diagnosis, prognosis and treatment of this condition.Methods and analysis This prospective observational cohort study aims to identify and characterise relevant clinical clusters that are reproducibly associated with various clinical outcomes in T2DM in our Mediterranean region. The COPERNICAN study will include 1200 subjects with newly diagnosed T2DM from 28 primary care centres from the city of Barcelona and the healthcare district of Lleida in Catalonia (Spain). Participants will undergo a comprehensive phenotypic evaluation including, among others, six relevant variables: age, antibodies against glutamic acid decarboxylase, body mass index, glycated haemoglobin (HbA1c), indexes of insulin sensibility (HOMA2-IR) and secretion (HOMA2-beta). We will collect additional comprehensive data on glucose-lowering and other drug treatments, clinical evaluation (including complications), laboratory parameters, advanced lipoprotein profile, dietary habits and physical activity. The linkage with the population database will be done to perform a pragmatic follow-up of participants as part of their usual clinical care. A state-of-the-art cluster analysis (k-means and hierarchical clustering) will be performed.Ethics and dissemination The present study complies with all the ethical aspects and protection of participant subjects complying with all current local and European Union legislation. All Ethics Committees from the institutions involved in the study (IR Sant Pau Ethics Committee, Ethics Committee for Drug Research at IDIAP Jordi Gol and University Hospital of Bellvitge Ethics Committee for Research) approved this protocol. Confidentiality and anonymity of the data are ensured according to the current Spanish Organic Law 3/2018 of 05 December.Trial registration number ClinicalTrials.gov. registration number NCT05333718, 27 January 2023.