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Type 2 diabetes mellitus, brain atrophy, and cognitive decline
Moran C, Beare R, Wang W, Callisaya M, Srikanth V, Alzheimer's Disease Neuroimaging Initiative (ADNI).. Neurology, 2019-01-23
Topic: Risk, prevention and care in population studies
Objective To study longitudinal relationships between type 2 diabetes mellitus (T2DM), cortical thickness, and cognitive function in older people with normal cognition, mild cognitive impairment, and Alzheimer disease (AD). Methods The sample was derived from the Alzheimer's Disease Neuroimaging Initiative cohort who underwent brain MRI and cognitive tests annually for 5 years. Presence of T2DM was based on fasting blood glucose ≥7.0mml/L or the use of glucose-lowering agents. We used latent growth curve modeling to explore longitudinal relationships between T2DM, cortical thickness, and cognitive function, adjusting for relevant covariates and testing for interactions. Results There were 124 people with T2DM (mean age 75.5 years, SD 6.2) and 693 without T2DM (mean age 75.1 years, SD 6.9) with at least 1 MRI available. AD and lower cortical thickness at study entry was associated with a lower chance of having a MRI available at each follow-up phase (all p p = 0.01). We found no direct effect of T2DM on decline in cortical thickness or cognitive function, but there was an indirect pathway linking T2DM and cognitive decline via baseline cortical thickness (β = -0.17, p = 0.022). There was an interaction between T2DM and education whereby the negative effect of T2DM on baseline cortical thickness was reduced in those with greater education (β = 0.34, p = 0.037). These associations changed minimally when adjusted for baseline cognitive diagnosis. Conclusions In an older cohort with low cerebrovascular disease burden, T2DM contributes to cognitive decline via neurodegeneration. Prior brain and cognitive reserve may protect against this effect.
Key findings
- Results There were 124 people with T2DM (mean age 75.5 years, SD 6.2) and 693 without T2DM (mean age 75.1 years, SD 6.9) with at least 1 MRI available.
- AD and lower cortical thickness at study entry was associated with a lower chance of having a MRI available at each follow-up phase (all p p = 0.01).
- We found no direct effect of T2DM on decline in cortical thickness or cognitive function, but there was an indirect pathway linking T2DM and cognitive decline via baseline cortical thickness (β = -0.17, p = 0.022).
Why it matters
This study found no direct effect of type 2 diabetes on decline in cortical thickness or cognitive function, but there was an indirect pathway linking diabetes and cognitive decline via baseline cortical thickness. The negative effect of diabetes on baseline cortical thickness was reduced in those with greater education.
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Study details
- Study designlongitudinal study
- Participants124
- Evidence strengthModerate
How this study scored 65/100
Published in a leading specialty journal, and it is a longitudinal study following the same people over time. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A longitudinal study following the same people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2019 — within 10 year(s) of the newest study here |
| Sample size | 2 / 4 | 124 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 158 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 17.6 citations a year over 9 year(s) since 2019 |
| Impact for its field and year | 4 / 6 | Cited 13.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 5 other studies in this library |
| Still being cited | 3 / 4 | Cited 51 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Effie M. Mitsis: h-index 51 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Monash University: institution h-index 1,146 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 30674592) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 65 / 100 | — |
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Read the original
- DOI: 10.1212/wnl.0000000000006955
- PubMed: 30674592
- Original source →
- Free full text: PubMed Central →
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
Moran, C., Beare, R., Wang, W., Callisaya, M., & Srikanth, V. (2019). Type 2 diabetes mellitus, brain atrophy, and cognitive decline. Neurology. https://doi.org/10.1212/wnl.0000000000006955
Vancouver
Moran C, Beare R, Wang W, Callisaya M, Srikanth V. Type 2 diabetes mellitus, brain atrophy, and cognitive decline. Neurology. 2019. doi:10.1212/wnl.0000000000006955. PMID: 30674592.
BibTeX
@article{moran2019-30674592,
author = {Moran, C. and Beare, R. and Wang, W. and Callisaya, M. and Srikanth, V.},
title = {{Type 2 diabetes mellitus, brain atrophy, and cognitive decline}},
journal = {Neurology},
year = {2019},
doi = {10.1212/wnl.0000000000006955},
pmid = {30674592},
url = {https://doi.org/10.1212/wnl.0000000000006955}
}
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