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Published on: January 11, 2013
Structural and functional alterations of the hippocampal subfields in T2DM with mild cognitive impairment and insulin
Chen Yang1, Huiyan Zhang2, Zihan Ma1
1The First Clinical Medical College of Gansu University of Chinese Medicine (Gansu Provincial Hospital), Gansu University of Chinese Medicine, Lanzhou, China.
Background:
Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance (IR) and is often accompanied by mild cognitive impairment (MCI). The detrimental effects of T2DM and IR on the hippocampus have been extensively demonstrated. Few studies have examined the effects of IR on structure and function of hippocampal subfields in T2DM-MCI patients.
Method:
A total of 104 T2DM patients were recruited in this prospective study and divided into four groups (T2DM-MCI-higherIR, n = 17; T2DM-MCI-lowerIR, n = 32; T2DM-nonMCI-higherIR, n = 19; T2DM-nonMCI-lowerIR, n = 36). Structure and function MRI data were captured. Clinical variables and neuropsychological scores were determined for all participants. Hippocampal subfield volume and functional connectivity were compared among four groups. Partial correlation analysis was performed between imaging indicators, clinical variables, and neuropsychological scores in all patients.
Results:
T2DM-MCI-higher IR group had the smallest volumes of bilateral hippocampal tail, right subiculum-body, right GC-ML-DG-body, and right CA4-body. IR in right hippocampal tail, right subiculum-body, and right GC-ML-DG-body exerted main effect. Furthermore, elevated functional connectivity was found between right subiculum-body and bilateral dorsolateral prefrontal cortex and right anterior cingulate-medial prefrontal cortex. Hippocampal subfield volume positively correlates with total cholesterol and triglycerides and negatively correlates with fasting insulin.
Conclusion:
The present study found that T2DM-MCI patients have structural and functional alterations in hippocampal subfields, and IR is a negative factor influencing the alteration of hippocampal subfields volume. These findings support the importance of IR in T2DM-MCI patients and might be potential neuroimaging biomarkers of cerebral impairment in T2DM-MCI patients.
Insights
Type 2 diabetes mellitus (T2DM) with mild cognitive impairment (MCI) shows hippocampal alterations. Insulin resistance (IR) negatively impacts hippocampal subfield volume and function, suggesting potential neuroimaging biomarkers for T2DM-MCI.
Area of Science:
- Neuroscience
- Endocrinology
- Radiology
Background:
- Type 2 diabetes mellitus (T2DM) is linked to insulin resistance (IR) and mild cognitive impairment (MCI).
- The hippocampus is vulnerable to T2DM and IR, but their specific effects on hippocampal subfields in T2DM-MCI patients are understudied.
Purpose of the Study:
- To investigate the structural and functional impact of insulin resistance (IR) on hippocampal subfields in patients with Type 2 diabetes mellitus (T2DM) and mild cognitive impairment (MCI).
Main Methods:
- 104 T2DM patients were categorized into four groups based on MCI status and IR levels.
- Structural and functional MRI data, clinical variables, and neuropsychological scores were collected.
- Hippocampal subfield volumes and functional connectivity were analyzed and correlated with clinical and cognitive data.
Main Results:
- Patients with T2DM-MCI and higher IR exhibited reduced volumes in multiple hippocampal subfields (e.g., tail, subiculum, GC-ML-DG, CA4).
- Insulin resistance significantly affected the volume of the right hippocampal tail, right subiculum-body, and right GC-ML-DG-body.
- Elevated functional connectivity was observed between the right subiculum-body and prefrontal cortex regions. Hippocampal volume correlated with lipid profiles and fasting insulin levels.
Conclusions:
- T2DM-MCI patients display structural and functional hippocampal alterations.
- Insulin resistance is a key factor exacerbating hippocampal subfield volume changes in T2DM-MCI.
- These neuroimaging findings highlight IR's role and suggest potential biomarkers for cerebral impairment in T2DM-MCI.
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