The Study
Blood-Brain Barrier Permeability Is Elevated in Type 2 Diabetes and Obesity: Associations with Cognitive Function and Metabolic Markers
This study looked at a group of people with diabetes and obesity and found that their brains seemed to have a leakier barrier, and they also did a bit worse on some memory and thinking tests. But it didn't change anything or follow people over time, so we can't say diabetes made the leak happen — it just showed that the two things often happened together.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at older people with type 2 diabetes and obesity and found their brain's protective barrier (BBB) was more leaky than in healthy people, even though their blood flow was normal.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — even without dementia, these people showed early brain changes that could explain why diabetes increases dementia risk.
- 2People with diabetes had 1.1 times higher BBB leakiness (g=1.10).
- 3Higher blood sugar (HbA1c) and lower good cholesterol (HDL) were linked to more leakiness.
- 4More leakiness was linked to worse memory and thinking skills.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Research Square
Year
2026
Authors
Anujit Saha, Wen Shi, Mohamad N. Elsharydah, Jeffrey Schaffert, Jack R Kaufman, Jennine Leary, Alison Jin, Jaime P. Almandoz, Hanzhang Lu, Binu P. Thomas
Related Content
Claims (6)
People with obesity and type 2 diabetes experience a reduction in cognitive function over time.
In older adults with type 2 diabetes and obesity, increased water permeability across the blood-brain barrier is linked to reduced performance in tasks requiring cognitive flexibility and processing speed.
In older adults with type 2 diabetes and obesity, higher levels of HbA1c are linked to greater water permeability across the blood-brain barrier.
In older adults with type 2 diabetes and obesity, higher levels of HDL cholesterol in the blood are linked to reduced water movement across the blood-brain barrier.
In older adults with type 2 diabetes and obesity, lower levels of LDL and total cholesterol in the blood are linked to increased water movement across the blood-brain barrier, suggesting this change reflects broader metabolic issues rather than direct damage to the barrier.
Older adults with type 2 diabetes and obesity show higher water movement across the blood-brain barrier than similar adults without these conditions, suggesting a link between long-term metabolic dysfunction and early changes in brain blood vessels that are not due to overall blood flow changes.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.