Clinical trial NCT05543967: Establish Diagnostic Models Based on Olfactory Function and Odor-induced Brain Activation for Diabetes-Related Cognitive Impairment
Official title: A Cross-sectional and Longitudinal Study to Establish Diagnostic Models Based on Olfactory Function and Odor-induced Brain Activation for Diabetes-Related Cognitive Impairment
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Type 2 Diabetes Mellitus
Cognitive Impairment
Lead sponsor: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School
Sponsor class: OTHER
First posted: 2022-09-16
Enrollment: 200
Sex: ALL
Minimum age (years): 40
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: CROSS_SECTIONAL
Sampling method: PROBABILITY_SAMPLE
Study population: 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.

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.

Detailed description: Patients with diabetes have increased risks of cognitive impairment and dementia, which affecting the quality of life and diabetes management. Therefore, it is an urgent challenge to identify non-invasive biomarkers for early diagnosis and prognosis of the cognitive decline in patients with diabetes. Previous research has shown that both olfactory dysfunction and decreased odor-induced brain activation are present before clinically measurable cognitive decrements in type 2 diabetes. 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. The investigators will recruit 200 patients with type 2 diabetes in the outpatient and inpatient departments. Health controls will be recruited from the community. At the baseline, clinical information collection, 100g-steamed bread meal test, biochemical measurement, cognitive assessments, olfactory test and functional magnetic resonance imaging(fMRI) scan will be conducted for all participants. Study duration was 3 years with a follow-up every 18 months. In the longitudinal study, all of the assessments will be repeated to evaluate changes of observational parameters.

Eligibility 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

Primary outcomes:
measure: Baseline cognitive performance
timeFrame: Day 1 of entry study
measure: Baseline olfactory threshold
timeFrame: Day 1 of entry study
measure: Baseline olfactory memory
timeFrame: Day 1 of entry study
measure: Baseline odor-induced brain fMRI activation
timeFrame: Within 1 week after cognitive assessments
measure: Longitudinal changes of cognitive performance
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
measure: Longitudinal changes of olfactory threshold
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
measure: Longitudinal changes of olfactory memory
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
measure: Longitudinal changes of odor-induced brain fMRI activation
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
Secondary outcomes:
measure: Baseline brain structural MRI scan
timeFrame: Within 1 week after cognitive assessments
measure: Baseline brain functional MRI scan
timeFrame: Within 1 week after cognitive assessments
measure: Longitudinal changes of brain structural MRI scan
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
measure: Longitudinal changes of functional MRI scan
timeFrame: From baseline to 18 months' follow-up and 36 months' follow-up
Other outcomes:
Locations:
city: Nanjing
country: China
facility: Department of Radiology, the Affiliated Drum Tower Hospital of Nanjing University
state: Jiangsu
Study officials:
References: