This document provides the full statistical analysis plan (SAP) for the INTIMET study (Insulin Resistance in Type 1 Diabetes Managed with Metformin), a randomised double-blinded placebo-controlled trial, designed to evaluate the effect of metformin on insulin resistance and cardiometabolic health in type 1 diabetes. This trial was prospectively registered within the Australian and New Zealand Clinical Trials Registry (ACTRN12619001440112). The study protocol has previously been published (Snaith JR et al, Diabetic Medicine 2021).

The authors have declared no competing interest.

ACTRN12619001440112

https://doi.org/10.1111/dme.14564

The study was received support from the Diabetes Australia Research Trust, St Vincent's Clinic Foundation, the University of New South Wales Cardiac Vascular and Metabolic Medicine Theme, the National Health and Medical Research Council, and philanthropic donations.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Human Research and Ethics Committee of St Vincents Hospital gave ethical approval for this work.

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Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Data may be made available on a case-by-case basis at the discretion of the primary sponsor and pending ethics committee approval.