Related Experiment Video
Updated: Dec 8, 2025

Osmotic Minipump Implantation for Increasing Glucose Concentration in Mouse Cerebrospinal Fluid
Published on: April 7, 2023
Metformin Use Is Associated With Slowed Cognitive Decline and Reduced Incident Dementia in Older Adults With Type 2
Katherine Samaras1,2,3, Steve Makkar4, John D Crawford4
1Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia k.samaras@garvan.org.au.
Objective:
Type 2 diabetes (diabetes) is characterized by accelerated cognitive decline and higher dementia risk. Controversy exists regarding the impact of metformin, which is associated with both increased and decreased dementia rates. The objective of this study was to determine the association of metformin use with incident dementia and cognitive decline over 6 years in participants with diabetes compared with those not receiving metformin and those without diabetes.
Research Design And Methods:
A prospective observational study was conducted of N = 1,037 community-dwelling older participants without dementia aged 70-90 years at baseline (the Sydney Memory and Ageing Study). Exclusion criteria were dementia, major neurological or psychiatric disease, or progressive malignancy. Neuropsychological testing measured cognitive function every 2 years; a battery of tests measured executive function, memory, attention/speed, language, and visuospatial function individually. These were used to determine the measure of global cognition. Incident dementia was ascertained by a multidisciplinary panel. Total brain, hippocampal, and parahippocampal volumes were measured by MRI at baseline and 2 years (n = 526). Data were analyzed by linear mixed modeling, including the covariates of age, sex, education, BMI, heart disease, hypertension, stroke, smoking, and apolipoprotein Eε4 carriage.
Results:
Of n = 1,037, 123 had diabetes; 67 received metformin (DM+MF) and were demographically similar to those who did not (DM-noMF) and participants without diabetes (no-DM). DM+MF had significantly slower global cognition and executive function decline compared with DM-noMF. Incident dementia was significantly higher in DM-noMF compared with DM+MF (odds ratio 5.29 [95% CI 1.17-23.88]; P = 0.05).
Conclusions:
Older people with diabetes receiving metformin have slower cognitive decline and lower dementia risk. Large randomized studies in people with and without diabetes will determine whether these associations can be attributed to metformin.
Related Concept Videos
Oral Hypoglycemic Agents: Biguanides and Glitazones
Dementia
The progression of dementia is generally gradual....
Psychoneuroimmunology: Diabetes and Cancer
Diabetes: Symptoms, Diagnosis, and Complications
Diabetes Mellitus: Type 2 and Gestational
Drug Dosing: Geriatric Patients

