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Glucose regulation, cognition, and brain MRI in type 2 diabetes: a systematic review
Geijselaers SLC, Sep SJS, Stehouwer CDA, Biessels GJ.. The lancet. Diabetes & endocrinology, 2014-08-24
Topic: Brain proteins, microglia and lab models
Type 2 diabetes is associated with cognitive dysfunction and structural brain changes. Abnormalities in glucose regulation are involved in several complications related to type 2 diabetes, but their role in these cerebral complications is unclear. We systematically reviewed studies of the association between glucose regulation (glycaemia, hypoglycaemic events, insulin concentration, insulin resistance, and glucose-lowering treatment) and cognitive function and brain abnormalities on MRI in people with type 2 diabetes. The 86 papers included showed that glycaemia, particularly high HbA1c concentration and glucose variability, are negatively associated with cognitive function in people with type 2 diabetes without dementia. However, the strength of this association is weak, and HbA1c generally accounted for less than 10% of the variance in cognition. Importantly, few studies have measured long-term cerebral outcomes, such as dementia and structural brain changes on MRI, and the effect of glucose-lowering treatment on these outcomes. More randomised controlled trials are needed to establish the effect of glucose-lowering treatment on long-term cognitive function in people with type 2 diabetes.
Key findings
- Type 2 diabetes is associated with cognitive dysfunction and structural brain changes.
- The 86 papers included showed that glycaemia, particularly high HbA1c concentration and glucose variability, are negatively associated with cognitive function in people with type 2 diabetes without dementia.
Why it matters
Across 86 studies of people with type 2 diabetes who did not have dementia, higher HbA1c and more variable blood glucose went along with somewhat poorer thinking scores. The link was weak, though: HbA1c generally explained less than 10% of the differences in cognition. Few studies followed people long enough to look at dementia or brain changes on MRI, so the authors say randomised trials are still needed to show whether lowering blood sugar protects long-term cognition.
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Study details
- Evidence strengthHigh
How this study scored 65/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for sample size, effect reported and studied in people because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (The lancet. Diabetes & endocrinology) |
| Journal's citation record | 3 / 4 | The Lancet Diabetes & Endocrinology: journal h-index 250 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A systematic review of all the studies on the question (from PubMed type “Systematic Review”) |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2015 — within 20 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 6 / 7 | Cited 377 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 29.0 citations a year over 13 year(s) since 2015 |
| Impact for its field and year | 3 / 6 | Cited 3.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 11 other studies in this library |
| Still being cited | 3 / 4 | Cited 81 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Geert Jan Biessels: h-index 105 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University Medical Center Utrecht: institution h-index 1,076 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 25163604) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 65 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1016/s2213-8587(14)70148-2
- PubMed: 25163604
- Original source →
- Free full text: Utrecht University Repository (Utrecht University) →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Geijselaers, S. L. C., Sep, S. J. S., Stehouwer, C. D. A., & Biessels, G. J. (2015). Glucose regulation, cognition, and brain MRI in type 2 diabetes: a systematic review. The lancet. Diabetes & endocrinology. https://doi.org/10.1016/s2213-8587(14)70148-2
Vancouver
Geijselaers SLC, Sep SJS, Stehouwer CDA, Biessels GJ. Glucose regulation, cognition, and brain MRI in type 2 diabetes: a systematic review. The lancet. Diabetes & endocrinology. 2015. doi:10.1016/s2213-8587(14)70148-2. PMID: 25163604.
BibTeX
@article{geijselaers2015-25163604,
author = {Geijselaers, S. L. C. and Sep, S. J. S. and Stehouwer, C. D. A. and Biessels, G. J.},
title = {{Glucose regulation, cognition, and brain MRI in type 2 diabetes: a systematic review}},
journal = {The lancet. Diabetes \& endocrinology},
year = {2015},
doi = {10.1016/s2213-8587(14)70148-2},
pmid = {25163604},
url = {https://doi.org/10.1016/s2213-8587(14)70148-2}
}
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