Establish Diagnostic Models Based on Olfactory Function and Odor-induced Brain Activation for Diabetes-Related Cognitive Impairment
A Cross-sectional and Longitudinal Study to Establish Diagnostic Models Based on Olfactory Function and Odor-induced Brain Activation for Diabetes-Related Cognitive Impairment
1 other identifier
observational
200
1 country
1
Brief Summary
This is a cross-sectional and longitudinal study to establish diagnostic models based on olfactory function assessments and odor-induced brain activation for cognitive impairment in patients with type 2 diabetes mellitus.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for all trials
Started Oct 2022
Typical duration for all trials
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
September 9, 2022
CompletedFirst Posted
Study publicly available on registry
September 16, 2022
CompletedStudy Start
First participant enrolled
October 18, 2022
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 30, 2025
CompletedStudy Completion
Last participant's last visit for all outcomes
August 31, 2025
CompletedOctober 26, 2022
August 1, 2022
2.7 years
September 9, 2022
October 23, 2022
Conditions
Outcome Measures
Primary Outcomes (8)
Baseline cognitive performance
The Montreal Cognitive Assessment (MoCA) score, ranges from 0 to 30, and higher scores mean better cognition.
Day 1 of entry study
Baseline olfactory threshold
Olfactory threshold test: score range 1-13.5, which is determined based on a series of binary dilutions of the N-butanol solution in light mineral oil. The higher the score is, the more sensitive the participant is in detecting an odor. Scores of 8-10 were considered normal olfactory sensitivity, whereas scores of 1-3 signified olfactory dysfunction or anosmia, and scores of ≥10 indicate better olfactory sensitivity.
Day 1 of entry study
Baseline olfactory memory
Olfactory memory test: Part A: Participants are shown 4 pictures for each odor (10 odors in total), then they need to select what they sniffed. Have a 10-minute break. Part B: Participants sniff 20 different odors, 10 of which are the same odors as in Part A. They need to select the picture and figure out whether the odor is old or new.
Day 1 of entry study
Baseline odor-induced brain fMRI activation
Each participant underwent a series of task fMRI scans to measure temporal brain response to four increasing concentrations of lavender odors (0.032%, 0.10%, 0.32%, and 1.0) diluted in 1,2-propanediol (Sigma-Aldrich, St. Louis, MO). The visual cues of "+" and "smell" were used for baseline and odor stimulation, respectively. Each concentration was assessed three times, with fresh air and scent occurring alternately. Participants were instructed to press a button once they smelled the lavender scent. A general linear model was used to estimate odor-induced brain activation. Contrasts between "fresh air \> rest" and "scent \> rest" for each participant were made to get odor-induced brain activation value. Bilateral parahippocampus, amygdala, piriform cortex, insula, orbitofrontal cortex, entorhinal cortex, and hippocampus were extracted and merged as olfactory regions of interest (ROIs) for further analyses.
Within 1 week after cognitive assessments
Longitudinal changes of cognitive performance
Compare the change of MoCA score from baseline to each follow-up time points (18 months' follow-up, 36 months' follow-up). The Montreal Cognitive Assessment (MoCA) score, ranges from 0 to 30, and higher scores mean better cognition.
From baseline to 18 months' follow-up and 36 months' follow-up
Longitudinal changes of olfactory threshold
Compare the change of olfactory threshold tests score from baseline to each follow-up time points (18 months' follow-up, 36 months' follow-up). Olfactory threshold test: score range 1-13.5, which is determined based on a series of binary dilutions of the N-butanol solution in light mineral oil. The higher the score is, the more sensitive the participant is in detecting an odor. Scores of 8-10 were considered normal olfactory sensitivity, whereas scores of 1-3 signified olfactory dysfunction or anosmia, and scores of ≥10 indicate better olfactory sensitivity.
From baseline to 18 months' follow-up and 36 months' follow-up
Longitudinal changes of olfactory memory
Compare the change of olfactory memory tests score from baseline to each follow-up time points (18 months' follow-up, 36 months' follow-up). Olfactory memory test: Part A: Participants are shown 4 pictures for each odor (10 odors in total), then they need to select what they sniffed. Have a 10-minute break. Part B: Participants sniff 20 different odors, 10 of which are the same odors as in Part A. They need to select the picture and figure out whether the odor is old or new.
From baseline to 18 months' follow-up and 36 months' follow-up
Longitudinal changes of odor-induced brain fMRI activation
Compare the change of odor-induced brain activation beta value from baseline to each follow-up time points (18 months' follow-up, 36 months' follow-up)
From baseline to 18 months' follow-up and 36 months' follow-up
Secondary Outcomes (4)
Baseline brain structural MRI scan
Within 1 week after cognitive assessments
Baseline brain functional MRI scan
Within 1 week after cognitive assessments
Longitudinal changes of brain structural MRI scan
From baseline to 18 months' follow-up and 36 months' follow-up
Longitudinal changes of functional MRI scan
From baseline to 18 months' follow-up and 36 months' follow-up
Study Arms (2)
Type 2 Diabetes Mellitus
These patients must have a definite diagnosis of type 2 diabetes mellitus (T2DM) according to the American Diabetes Association (ADA) standards. Some of these patients have symptoms of cognitive impairment, while others have normal cognition. All T2DM patients will undergo physical exam, cognitive and olfactory test as well as structural and brain functional MRI at baseline and follow-up time points.
Healthy Control
These participants have normal glucose tolerance and normal cognition. All HC subjects will undergo physical exam, cognitive and olfactory test as well as structural and brain functional MRI at baseline and follow-up time points.
Interventions
Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Rey Auditory Verbal Learning Test (RAVLT), Boston Naming Test (BNT), Digit Span Test (DST), Trail Making Test (TMT).
Olfactory Threshold, Odor Identification Score, Odor Memory Score.
resting-state fMRI, odor-induced fMRI.
Eligibility Criteria
T2DM patients will be recruited from the outpatient and inpatient units of the endocrinology department of the investigator's hospital. Healthy control will be recruited in the community.
You may qualify if:
- 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
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Department of Radiology, the Affiliated Drum Tower Hospital of Nanjing University
Nanjing, Jiangsu, 210008, China
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- COHORT
- Time Perspective
- CROSS SECTIONAL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
September 9, 2022
First Posted
September 16, 2022
Study Start
October 18, 2022
Primary Completion
June 30, 2025
Study Completion
August 31, 2025
Last Updated
October 26, 2022
Record last verified: 2022-08
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ANALYTIC CODE
- Time Frame
- during the 12 months after the end of study
IPD sharing will be made during the 12 months after the end of study, and the original data can be obtained from the PI if necessary.