METformin and FINGER Intervention to Prevent Cognitive Impairment and Disability in Older Adults at Risk for Dementia

After being identified and pre-screened in relevant registers, potential participants will undergo a screening assessment (after providing informed consent for the screening procedures) where inclusion criteria related to both cognition and cardiovascular/lifestyle risk factors will be checked. Participants meeting the inclusion criteria will undergo the exclusion criteria assessment with the study physician. Eligible participants will be invited to the baseline visit where informed consent for the full study will be signed, baseline assessment will be conducted, and participants will be randomized to either the FINGER 2.0 multidomain lifestyle-based intervention or self-guided multidomain lifestyle intervention group. Based on the results of the baseline assessment, the eligibility to the metformin/placebo treatment will be assessed in all participants randomized to the FINGER 2.0 intervention group. Eligible participants will be further randomized to one of the three metformin treatment groups (metformin 2000mg/day, metformin 1000mg/day, or placebo). Non eligible participants will continue the study by following the structured lifestyle intervention alone. In the self-guided intervention group, participants will build their own healthy lifestyle program based on standard healthy lifestyle advice that they will receive at individual consultations with the study physician/nurse as part of the visits. Within the FINGER 2.0 intervention group, participants will be invited to attend individual consultations and group meeting sessions in relation to the four intervention components (diet, physical activity, cognitive training, and cardiovascular/metabolic risk monitoring). As part of the physical activity component, group training sessions with a physiotherapist/professional trainer will be organized both at a gym as well as online. Within the cognitive training component, participants will have access to an online cognitive training program for independent training sessions. Individually tailored recommendations and plans will be provided to each participant. Metformin and placebo will be dispensed every 3 months, both administered orally. The active drug is Glucophage® XR 500. All participants randomized to the metformin/placebo groups will receive 4 identical tablets per day as follows: * 2000mg/day: 4x500mg metformin * 1000mg/day: 2x500mg metformin + 2x500mg placebo * Placebo: 4x500mg placebo. Metformin will be titrated weekly from 500mg/day up to 2000mg/day over 4 weeks. Participants who do not tolerate the treatment will be allowed to remain in the study either in a lower dose treatment group, or receiving the structured lifestyle intervention only. Participants will not be actively told to what lifestyle intervention group they have been assigned and assessors for primary and secondary outcomes will be blinded to the lifestyle group allocation. The metformin/placebo treatment will be conducted in double blind.