Relationship Between Diabetes and Cognitive Impairment Based on Olfactory Function Assessment and Functional MRI

Completed

• Conditions: Cognitive Impairment; Obesity; Diabetes Mellitus
• Interventions: Behavioral: Cognitive assessment; Other: functional magnetic resonance imaging; Other: olfactory function measurement; Procedure: bariatric surgery

• Registration Number: NCT02738671
• Lead Sponsor: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School

Brief Summary

The purpose of this study is to explore the relationship between diabetes and cognitive impairment by olfactory function assessment and functional MRI.

Detailed Description

Previous research has shown both obesity and diabetes are associated with an increased risk of cognitive impairment. Meanwhile, olfactory impairment is associated with incident (amnestic mild cognitive impairment) aMCI and progression from aMCI to (Alzheimer disease) AD dementia. On one hand, in the cross-sectional study, biometric measurements, cognitive assessment, olfactory function and fMRI results are analysed to explore the differences among T1DM patients, T2DM patients and non-diabetic people . One the other hand, in the longitudinal study, changes in olfactory function and fMRI results in diabetic and non-diabetic obese patients both at baseline and 6 months after their bariatric surgery are collected to investigate whether better glucose and weight control benefit brain function.

Study Timeline

• Study Start: 2016-01
• Study First Submitted: 2016-02-25
• Study First Submitted QC: 2016-04-13
• Study First Posted: 2016-04-14
• Status Verified: 2016-10
• Primary Completion: 2019-03
• Study Completion: 2019-05
• Last Update Submitted: 2019-05-29
• Last Update Posted: 2019-05-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 250

Inclusion Criteria

1. Have a certain level of education (at least 6 years), able to complete the cognitive assessment;
2. Disease duration >1 year.

Exclusion Criteria

1. 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);
2. Montreal Cognitive Assessment (MoCA,Beijing edition) score of < 20;
3. History of neurologic or psychological illness;
4. History of cardiovascular or cerebrovascular disease;
5. Abnormal results of thyroid hormones, vitamin B12, and folate.
6. Metal implants, unable to complete the MR examinations or evidence of cortical infarcts, hemorrhage, or structural brain disease other than atrophy, lacunes, or white matter lesions;
7. Left-handed;
8. Partial or complete olfactory dysfunction associated with sinusitis,allergic rhinitis, and deviated nasal septum.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Type 1 Diabetes Mellitus	olfactory function measurement	These T1DM patients have late diabetes onset.(latent autoimmune diabetes in adult, LADA)
Type 2 Diabetes Mellitus	functional magnetic resonance imaging	A subgroup of these T2DM patients are obesity patients who will have the bariatric surgery. These obese T2DM subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain MRI at baseline and 6 months after their surgery.
Type 2 Diabetes Mellitus	olfactory function measurement	A subgroup of these T2DM patients are obesity patients who will have the bariatric surgery. These obese T2DM subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain MRI at baseline and 6 months after their surgery.
Type 2 Diabetes Mellitus	bariatric surgery	A subgroup of these T2DM patients are obesity patients who will have the bariatric surgery. These obese T2DM subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain MRI at baseline and 6 months after their surgery.
Control	Cognitive assessment	A subgroup of these non-diabetic people are obesity patients who will have the bariatric surgery. These obese subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain fMRI at baseline and 6 months after their surgery.
Control	olfactory function measurement	A subgroup of these non-diabetic people are obesity patients who will have the bariatric surgery. These obese subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain fMRI at baseline and 6 months after their surgery.
Control	bariatric surgery	A subgroup of these non-diabetic people are obesity patients who will have the bariatric surgery. These obese subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain fMRI at baseline and 6 months after their surgery.
Type 1 Diabetes Mellitus	functional magnetic resonance imaging	These T1DM patients have late diabetes onset.(latent autoimmune diabetes in adult, LADA)
Control	functional magnetic resonance imaging	A subgroup of these non-diabetic people are obesity patients who will have the bariatric surgery. These obese subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain fMRI at baseline and 6 months after their surgery.
Type 1 Diabetes Mellitus	Cognitive assessment	These T1DM patients have late diabetes onset.(latent autoimmune diabetes in adult, LADA)
Type 2 Diabetes Mellitus	Cognitive assessment	A subgroup of these T2DM patients are obesity patients who will have the bariatric surgery. These obese T2DM subjects will undergo a physical exam, cognitive and olfactory test as well as structural and functional brain MRI at baseline and 6 months after their surgery.

Primary Outcome Measures

Name	Time	Method
Physical assessments.	1 Day	BMI(body mess index) in kg/m\^2
Montreal Cognitive Assessment (MoCA)	1 Day	The MoCA is a cognitive screening test designed to assist Health Professionals in detection of mild cognitive impairment.
Functional MRI of the brain tracking testing.	1day
Participants' personal information	1 day	Self-reported information(education in years)
Olfactory memory test:	1 day	PART A: Participants are shown 4 pictures for each odor(10 odors in total). They select what they sniffed.; 10 minutes break.; PART B: Participants sniff 20 different odors , 10 of which are same odors in PART A. They select the picture and figure out whether the odor is old or new.
Glycaemic control measured by blood test.	1 day	HbA1c
Olfactory threshold test	1 day	Olfactory threshold test: The same odor with 2 different concentrations are given to the participant each time to find out which one is more intense. (Olfactory software will analyse and give threshold score depending on participant's choice.)

Secondary Outcome Measures

Name	Time	Method
Change from baseline Functional magnetic resonance imagine	6 months after the bariatric surgery (for diabetic and non-diabetic obese patients)
Change form baseline Glycaemic control measured by blood test.	6 months after the bariatric surgery (for diabetic and non-diabetic obese patients)	HbA1c

Trial Locations

Locations (1)

at Division of Endocrinology, the Affiliated Drum Tower Hospital of Nanjing University; 🇨🇳 Nanjing, Jiangsu, China