Comment on Samara et al. Metformin Use Is Associated With Slowed Cognitive Decline and Reduced Incident Dementia in Older Adults With Type 2 Diabetes: The Sydney Memory and Ageing Study. Diabetes Care 2020;43:2691–2701
Abstract
We have read with great interest the articlepublishedbySamaraset al. (1); the authors found an association of metformin use with slowed cognitive decline and lower risk of incident dementia in older adults with type 2 diabetes. In this work, theauthors reportedan impressive 81% risk reduction in the incidence of dementia between patients with diabetes and metformin (DM1MF) compared with the group with diabetes without metformin (DM-noMF). We found some aspects of the study worth further discussion. First, there is high contrast in the number of medications required in the DM1MF and DM-noMF groups. In the metformin group, 50% of the subjects were taking at least one additional antidiabetic drug added to metformin. In contrast, in the DM-noMF group, 60% of the subjects were on a diet-only regimen. Most international guidelines have metformin as foundational drug therapy in patients with type 2 diabetes (2). Why is metformin not the treatment for all of these subjects? Several reasons could explain these findings, e.g., good glycemic control with nonpharmacological therapy, poor tolerability to metformin, or contraindications to its use, such as renal impairment. It came to our attention that renal impairment markers like microalbuminuria and estimated glomerular filtration rate (eGFR) were not evaluated, even though several works describe the relation between renal impairment and risk of dementia (3,4). Orkaby et al. (4) analyzed the data of a retrospective cohort of patients…
How strong is the evidence?
Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence.
Read the paper
Related studies
- Metformin as an adjuvant in breast cancer treatment
- Metformin Lysosomal Targeting: A Novel Aspect to Be Investigated for Metformin Repurposing in Neurodegenerative Diseases?
- Aberrant HSF1 signaling activation underlies metformin amelioration of myocardial infarction in mice
- Metformin induces ZFP36 by mTORC1 inhibition in cervical cancer-derived cell lines
- Protein Interaction Network for Identifying Vascular Response of Metformin (Oral Antidiabetic)
- Preventing Long COVID With Metformin
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.