APOE and dementia: The MET-FINGER study aims to test a FINGER 2.0 multimodal intervention (active arm), combining a Structured Multimodal Lifestyle Intervention (SMLI, based on the original FINGER model) with metformin (where appropriate) in a APOE ε4-enriched population of older adults at-risk for dementia, against a Self-Guided Multimodal Intervention (SGMI, general health advice; control arm).