Diagnostic models for cognitive impairment in diabetes using smell tests and brain scans

A Cross-sectional and Longitudinal Study to Establish Diagnostic Models Based on Olfactory Function and Odor-induced Brain Activation for Diabetes-Related Cognitive Impairment

Observational The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School · NCT05543967

This study is testing if smell tests and brain scans can help find early signs of thinking problems in people with type 2 diabetes.

Quick facts

Study typeObservational
Enrollment200 (estimated)
Ages40 Years to 75 Years
SexAll
SponsorThe Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School Academic / other
Locations1 site (Nanjing, Jiangsu)
Trial IDNCT05543967 on ClinicalTrials.gov

What this trial studies

This observational study aims to establish diagnostic models that utilize olfactory function assessments and odor-induced brain activation to identify cognitive impairment in patients with type 2 diabetes mellitus. It will involve recruiting 200 patients with diabetes and healthy controls, conducting a series of assessments including cognitive tests, olfactory function measurements, and functional MRI scans. The study will be conducted over three years with follow-ups every 18 months to evaluate changes in cognitive and olfactory parameters. The goal is to identify non-invasive biomarkers for early diagnosis and prognosis of cognitive decline in diabetic patients.

Who should consider this trial

Good fit: Ideal candidates for this study are individuals aged 40-75 years with a diagnosis of type 2 diabetes for more than one year.

Not a fit: Patients with acute diseases, significant cognitive impairment, or those with conditions affecting olfactory function may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to early identification and intervention for cognitive impairment in patients with type 2 diabetes, potentially improving their quality of life.

How similar studies have performed: Previous studies have indicated that olfactory dysfunction and brain activation changes can precede cognitive decline, suggesting that this approach may be promising.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Aged 40-75 years
* Right handedness
* Possessed over 6-year education
* Provision of informed consent prior to any study specific procedures
* Disease duration of T2DM patients \>1 year

Exclusion Criteria:

* Control participants would be excluded if they had a fasting blood glucose level \>7.0 mmol/L; glucose level\> 7.8 mmol/L after oral glucose tolerance test (OGTT); HbA1c\>5.7%
* Control participants would be excluded if they had a Montreal Cognitive Assessment (MoCA, Beijing edition) score of \< 26
* Any acute disease
* History of neurologic or psychological illness
* Abnormal results of thyroid hormones, vitamin B12, and folate
* Metal implants, unable to complete the MR scanning
* Partial or complete olfactory dysfunction associated with sinusitis, allergic rhinitis, and deviated nasal septum
* Pregnant or lactating women
* Participating in other clinical trials at the same time or within 6 months prior to the start of the trial

Where this trial is running

Nanjing, Jiangsu

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Type 2 Diabetes MellitusCognitive Impairment
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.