Publications by authors named "Gijung Jung"

11 Publications

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The clinical use of blood-test factors for Alzheimer's disease: improving the prediction of cerebral amyloid deposition by the QPLEX Alz plus assay kit.

Exp Mol Med 2021 Jun 9. Epub 2021 Jun 9.

Department of Biochemistry and Biomedical Sciences, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea.

Alzheimer's disease (AD) is the leading cause of dementia, and many studies have focused on finding effective blood biomarkers for the accurate diagnosis of this disease. Predicting cerebral amyloid deposition is considered the key for AD diagnosis because a cerebral amyloid deposition is the hallmark of AD pathogenesis. Previously, blood biomarkers were discovered to predict cerebral amyloid deposition, and further efforts have been made to increase their sensitivity and specificity. In this study, we analyzed blood-test factors (BTFs) that can be commonly measured in medical health check-ups from 149 participants with cognitively normal, 87 patients with mild cognitive impairment, and 64 patients with clinically diagnosed AD dementia with brain amyloid imaging data available. We demonstrated that four factors among regular health check-up blood tests, cortisol, triglyceride/high-density lipoprotein cholesterol ratio, alanine aminotransferase, and free triiodothyronine, showed either a significant difference by or correlation with cerebral amyloid deposition. Furthermore, we made a prediction model for Pittsburgh compound B-positron emission tomography positivity, using BTFs and the previously discovered blood biomarkers, the QPLEX Alz plus assay kit biomarker panel, and the area under the curve was significantly increased up to 0.845% with 69.4% sensitivity and 90.6% specificity. These results show that BTFs could be used as co-biomarkers and that a highly advanced prediction model for amyloid plaque deposition could be achieved by the combinational use of diverse biomarkers.
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http://dx.doi.org/10.1038/s12276-021-00638-3DOI Listing
June 2021

Validation of the Korean Version of the Anosognosia Questionnaire for Dementia.

Psychiatry Investig 2021 Apr 25;18(4):324-331. Epub 2021 Apr 25.

Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea.

Objective: Anosognosia is a common phenomenon in individuals with dementia. Anosognosia Questionnaire for dementia (AQ-D) is a well-known scale for evaluating anosognosia. This study aimed to establish a Korean version of the AQ-D (AQ-D-K) and to evaluate the reliability and validity of the AQ-D-K in patients with Alzheimer's disease (AD) dementia.

Methods: We translated the original English version of AQ-D into Korean (AQ-D-K). Eighty-four subjects with very mild or mild AD dementia and their caregivers participated. Reliability of AQ-D-K was assessed by internal consistency and one-month test-retest reliability. Construct validity and concurrent validity were also evaluated.

Results: Internal consistencies of the AQ-D-K patient form and caregiver form were high (Cronbach alpha 0.95 and 0.93, respectively). The test-retest reliability of AQ-D-K measured by intra-class correlation coefficient was 0.84. Three factors were identified: 1) anosognosia of instrumental activity of daily living; 2) anosognosia basic activity of daily living; and 3) anosognosia of depression and disinhibition. AQ-D-K score was significantly correlated with the clinician-rated anosognosia rating scale (ARS), center for epidemiological studies-depression scale (CES-D) and state-trait anxiety inventory (STAI).

Conclusion: The findings suggest that the AQ-D-K is a reliable and valid scale for evaluating anosognosia for AD dementia patients using Korean language.
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http://dx.doi.org/10.30773/pi.2020.0364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8103024PMC
April 2021

Synergistic Effect of Serum Homocysteine and Diabetes Mellitus on Brain Alterations.

J Alzheimers Dis 2021 ;81(1):287-295

Institute of Human Behavioral Medicine, Medical Research Center Seoul National University, Seoul, Republic of Korea.

Background: Both elevated blood homocysteine and diabetes mellitus (DM) are related to cognitive impairments or dementia. A previous study also demonstrated that the association between homocysteine and cognitive decline was much stronger in individuals with DM than in those without DM.

Objective: This study aimed to examine the interactive effect of blood homocysteine and DM on brain pathological changes including brain atrophy, amyloid-β and tau deposition, and small vessel disease (SVD) related to cognitive impairments.

Methods: A total of 430 non-demented older adults underwent comprehensive clinical assessment, measurement of serum homocysteine level, [11C] Pittsburgh Compound B (PiB) PET, [18F] AV-1451 PET, and brain MRI.

Results: The interactive effect of homocysteine with the presence of DM on brain atrophy, especially in aging-related brain regions, was significant. Higher homocysteine concentration was associated with more prominent brain atrophy in individuals with DM, but not in those without DM. In contrast, interaction effect of homocysteine and DM was found neither on Alzheimer's disease (AD) pathologies, including amyloid-β and tau deposition, nor white matter hyperintensity volume as a measure of SVD.

Conclusion: The present findings suggest that high blood homocysteine level and DM synergistically aggravate brain damage independently of AD and cerebrovascular disease. With regard to preventing dementia or cognitive decline in older adults, these results support the importance of strictly controlling blood glucose in individuals with hyperhomocysteinemia and lowering blood homocysteine level in those with DM.
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http://dx.doi.org/10.3233/JAD-210036DOI Listing
January 2021

Blood Hemoglobin, Alzheimer Pathologies, and Cognitive Impairment: A Cross-Sectional Study.

Front Aging Neurosci 2021 24;13:625511. Epub 2021 Feb 24.

Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, South Korea.

Despite known associations between low blood hemoglobin level and Alzheimer's disease (AD) or cognitive impairment, the underlying neuropathological links are poorly understood. We aimed to examine the relationships of blood hemoglobin levels with AD pathologies (i.e., cerebral beta-amyloid [Aβ] deposition, tau deposition, and AD-signature degeneration) and white matter hyperintensities (WMHs), which are a measure of cerebrovascular injury. We also investigated the association between hemoglobin level and cognitive performance, and then assessed whether such an association is mediated by brain pathologies. A total of 428 non-demented older adults underwent comprehensive clinical assessments, hemoglobin level measurement, and multimodal brain imaging, including Pittsburgh compound B-positron emission tomography (PET), AV-1451 PET, fluorodeoxyglucose (FDG)-PET, and magnetic resonance imaging. Episodic memory score and global cognition scores were also measured. A lower hemoglobin level was significantly associated with reduced AD-signature cerebral glucose metabolism (AD-CM), but not Aβ deposition, tau deposition, or WMH volume. A lower hemoglobin level was also significantly associated with poorer episodic memory and global cognition scores, but such associations disappeared when AD-CM was controlled as a covariate, indicating that AD-CM has a moderating effect. The present findings suggest that low blood hemoglobin in older adults is associated with cognitive decline via reduced brain metabolism, which seems to be independent of those aspects of AD-specific protein pathologies and cerebrovascular injury that are reflected in PET and MRI measures.
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http://dx.doi.org/10.3389/fnagi.2021.625511DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943867PMC
February 2021

Performance of the QPLEX™ Alz plus assay, a novel multiplex kit for screening cerebral amyloid deposition.

Alzheimers Res Ther 2021 01 6;13(1):12. Epub 2021 Jan 6.

Department of Biochemistry and Biomedical Sciences, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea.

Background: Alzheimer's disease (AD) is an irreversible neurodegenerative disease characterized by the hallmark finding of cerebral amyloid deposition. Many researchers have tried to predict the existence of cerebral amyloid deposition by using easily accessible blood plasma samples, but the effectiveness of such strategies remains controversial.

Methods: We developed a new multiplex kit, the QPLEX™ Alz plus assay kit, which uses proteomics-based blood biomarkers to prescreen for cerebral amyloid deposition. A total of 300 participants who underwent Pittsburgh compound B (PiB)-positron emission tomography (PET) which allows imaging of cerebral amyloid deposition were included in this study. We compared the levels of QPLEX™ biomarkers between patients who were classified as PiB-negative or PiB-positive, regardless of their cognitive function. Logistic regression analysis followed by receiver operating characteristic (ROC) curve analysis was performed. The kit accuracy was tested using a randomized sample selection method.

Results: The results obtained using our assay kit reached 89.1% area under curve (AUC) with 80.0% sensitivity and 83.0% specificity. Further validation of the QPLEX™ Alz plus assay kit using a randomized sample selection method showed an average accuracy of 81.5%.

Conclusions: Our QPLEX™ Alz plus assay kit provides preliminary evidence that it can be used as blood marker to predict cerebral amyloid deposition but independent validation is needed.
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http://dx.doi.org/10.1186/s13195-020-00751-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7786945PMC
January 2021

Genetic associations of in vivo pathology influence Alzheimer's disease susceptibility.

Alzheimers Res Ther 2020 11 19;12(1):156. Epub 2020 Nov 19.

Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea.

Introduction: Although the heritability of sporadic Alzheimer's disease (AD) is estimated to be 60-80%, addressing the genetic contribution to AD risk still remains elusive. More specifically, it remains unclear whether genetic variants are able to affect neurodegenerative brain features that can be addressed by in vivo imaging techniques.

Methods: Targeted sequencing analysis of the coding and UTR regions of 132 AD susceptibility genes was performed. Neuroimaging data using C-Pittsburgh Compound B positron emission tomography (PET), F-fluorodeoxyglucose PET, and MRI that are available from the KBASE (Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's disease) cohort were acquired. A total of 557 participants consisted of 336 cognitively normal (CN) adults, 137 mild cognitive impairment (MCI), and 84 AD dementia (ADD) groups.

Results: We called 5391 high-quality single nucleotide variants (SNVs) on AD susceptibility genes and selected significant associations between variants and five in vivo AD pathologies: (1) amyloid β (Aβ) deposition, (2) AD-signature region cerebral glucose metabolism (AD-Cm), (3) posterior cingulate cortex (PCC) cerebral glucose metabolism (PCC-Cm), (4) AD-signature region cortical thickness (AD-Ct), and (5) hippocampal volume (Hv). The association analysis for common variants (allele frequency (AF) > 0.05) yielded several novel loci associated with Aβ deposition (PIWIL1-rs10848087), AD-Cm (NME8-rs2722372 and PSEN2-rs75733498), AD-Ct (PSEN1-rs7523) and, Hv (CASS4-rs3746625). Meanwhile, in a gene-based analysis for rare variants (AF < 0.05), cases carrying rare variants in LPL, FERMT2, NFAT5, DSG2, and ITPR1 displayed associations with the neuroimaging features. Exploratory voxel-based brain morphometry between the variant carriers and non-carriers was performed subsequently. Finally, we document a strong association of previously reported APOE variants with the in vivo AD pathologies and demonstrate that the variants exert a causal effect on AD susceptibility via neuroimaging features.

Conclusions: This study provides novel associations of genetic factors to Aβ accumulation and AD-related neurodegeneration to influence AD susceptibility.
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http://dx.doi.org/10.1186/s13195-020-00722-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7678113PMC
November 2020

Serum Uric Acid, Alzheimer-Related Brain Changes, and Cognitive Impairment.

Front Aging Neurosci 2020 5;12:160. Epub 2020 Jun 5.

Institute of Human Behavioral Medicine, Medical Research Center Seoul National University, Seoul, South Korea.

Background: Despite known associations of lower serum uric acid (UA) with Alzheimer's disease (AD) dementia or AD-related cognitive impairment, little is known regarding the underlying patho-mechanisms. We aimed to examine the relationships of serum UA with in vivo AD pathologies including cerebral beta-amyloid (Aβ) and tau deposition, AD-signature region cerebral glucose metabolism (AD-CM), and white matter hyperintensities (WMH). We also investigated the association between serum UA and cognitive performance, and then assessed whether such an association is mediated by the brain pathologies.

Methods: A total of 430 non-demented older adults underwent comprehensive clinical assessments, measurement of serum UA level, and multimodal brain imaging, including Pittsburgh compound B-positron emission tomography (PET), AV-1451 PET, fluorodeoxyglucose (FDG)-PET, and magnetic resonance imaging scans. Mini-Mental State Examination (MMSE) and word list recall (WLR) test scores were used to measure cognitive performance.

Results: Serum UA level was significantly associated with AD-CM, but not with Aβ deposition, tau deposition, or WMH volume. Serum UA levels also had significant association with WLR and marginal association with MMSE; such associations disappeared when AD-CM was controlled as a covariate, indicating that AD-CM has a mediating effect.

Conclusion: The findings of the present study indicate that there is an association of low serum UA with AD-related cerebral hypometabolism, and whether this represents a causal relationship remains to be determined.
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http://dx.doi.org/10.3389/fnagi.2020.00160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7291838PMC
June 2020

Comparison of Amyloid Positivity Rate and Accumulation Pattern between Amnestic and Non-Amnestic Type Mild Cognitive Impairment.

Psychiatry Investig 2020 Jun 11;17(6):603-607. Epub 2020 Jun 11.

Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea.

Objective: We aimed to compare cerebral beta-amyloid protein (Aβ) positivity rate and amyloid accumulation pattern on amyloid positron emission tomography (PET) between mild cognitive impairment (MCI) subtypes, i.e. amnestic mild cognitive impairment (aMCI) and non-amnestic mild cognitive impairment (naMCI).

Methods: The study participants were 34 naMCI patients and age-, sex- and education-matched 68 aMCI patients (1:2 ratio) who visited the Dementia and Age-Associated Cognitive Decline Clinic of the Seoul National University Hospital. All participants received comprehensive clinical and neuropsychological assessments and [F] florbetaben PET.

Results: Aβ positivity rate of naMCI group (26.5%) was significantly lower than that of aMCI group (64.7%). Among Aβ positive individuals, there was no difference in Aβ accumulation pattern between naMCI and aMCI.

Conclusion: The findings suggest that MCI subtypes based on impaired cognitive domains have a differential association with brain Aβ deposition, a core pathology of AD. Amnestic subtype of MCI are more closely associated with cerebral Aβ deposition compared to nonamnestic subtype. In contrast, the pattern of amyloid deposition does not appear to have any difference between the subtypes.
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http://dx.doi.org/10.30773/pi.2020.0063DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7324742PMC
June 2020

Coffee intake and decreased amyloid pathology in human brain.

Transl Psychiatry 2019 10 22;9(1):270. Epub 2019 Oct 22.

Institute of Human Behavioral Medicine, Medical Research Center Seoul National University, Seoul, 03080, Republic of Korea.

Several epidemiological and preclinical studies supported the protective effect of coffee on Alzheimer's disease (AD). However, it is still unknown whether coffee is specifically related with reduced brain AD pathologies in human. Hence, this study aims to investigate relationships between coffee intake and in vivo AD pathologies, including cerebral beta-amyloid (Aβ) deposition, the neurodegeneration of AD-signature regions, and cerebral white matter hyperintensities (WMH). A total of 411 non-demented older adults were included. Participants underwent comprehensive clinical assessment and multimodal neuroimaging including [C] Pittsburgh compound B-positron emission tomography (PET), [F] fluorodeoxyglucose PET, and magnetic resonance imaging scans. Lifetime and current coffee intake were categorized as follows: no coffee or <2 cups/day (reference category) and ≥2 cups/day (higher coffee intake). Lifetime coffee intake of ≥2 cups/day was significantly associated with a lower Aβ positivity compared to coffee intake of <2 cups/day, even after controlling for potential confounders. In contrast, neither lifetime nor current coffee intake was not related to hypometabolism, atrophy of AD-signature region, and WMH volume. The findings suggest that higher lifetime coffee intake may contribute to lowering the risk of AD or related cognitive decline by reducing pathological cerebral amyloid deposition.
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http://dx.doi.org/10.1038/s41398-019-0604-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6805864PMC
October 2019

A Multidomain Intervention for Modifying Lifestyle Habits Reduces the Dementia Risk in Community-Dwelling Older Adults: A Single-Blinded Randomized Controlled Pilot Study.

J Alzheimers Dis 2019 ;70(1):51-60

Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea.

We aimed to examine the feasibility and effectiveness of a multidomain intervention including intensive and maintenance programs for reducing the risk of dementia in at-risk older adults. Community-dwelling older adults (aged ≥60 years) without dementia but having several risk factors for dementia (N = 32; 89% female; mean age±standard deviation, 76.8±4.7 years) were assigned to three parallel programs: intensive plus maintenance (INT+MNT), intensive only (INT-only), and active control. Subjects in INT+MNT and INT-only groups participated in a 4-week intensive group-based lifestyle modification program that focused on physical activity, vascular risk factors, dietary habits, cognitive activities, and social engagement. INT+MNT participants underwent an additional 20-week maintenance program to consolidate modified habits. The modified Australian National University-Alzheimer's Disease Risk Index (ANU-ADRI) score was used as the primary outcome measure for dementia risk. The changes in ANU-ADRI scores exhibited a significant group-by-time interaction: the INT+MNT group showed significant improvement at 24 weeks (β= -6.05; SE = 1.86; p = 0.002), while the INT-only group did not. Additional exploratory analyses showed that the reduction in ANU-ADRI scores was caused by changes in protective factors rather than in risk factors. The INT + MNT group also showed greater improvement in executive function at 4 and 24 weeks (both p = 0.044), whereas changes in global cognitive function did not reach significance (p = 0.055). A 24-week multidomain dementia prevention involving a maintenance strategy for sustaining modified lifestyle habits reduced the risk of dementia and improved executive function in at-risk older adults.
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http://dx.doi.org/10.3233/JAD-190016DOI Listing
September 2020

Vascular risk modulates the relationship between cerebral amyloid deposition and subjective memory complaints.

Neuropsychiatr Dis Treat 2019 4;15:637-645. Epub 2019 Mar 4.

Institute of Human Behavioral Medicine, Medical Research Center, Seoul National University, Seoul, Republic of Korea,

Purpose: We aimed to investigate the relationships of cerebral amyloid beta (Aβ) deposition and neurodegeneration (ND) with subjective memory complaints (SMCs) in cognitively normal (CN) individuals, focusing specially on the modulating effects of vascular risk (VR) on those relationships.

Participants And Methods: A total of 230 CN elderly individuals underwent comprehensive clinical assessments including the Subjective Memory Complaints Questionnaire (SMCQ), VR assessment, and multimodal brain imaging including [C] Pittsburgh compound B positron emission tomography (PET), [F] fluorodeoxyglucose-PET, and magnetic resonance imaging.

Results: We found a significant overall positive association between cerebral Aβ retention and SMCQ score. In addition, we found a significant cerebral Aβ retention × VR interaction effect on the SMCQ score. Subgroup analyses showed that the Aβ-SMC association was found only in VR-negative, and not in VR-positive, individuals. We found no relationship between ND and SMCQ.

Conclusion: Our findings suggest that SMC in CN elderly individuals reflects early accumulation of Aβ in the brain. Given the modulating effect of VR on the Aβ-SMC relationship, SMC can be used as a meaningful marker of early Aβ deposition in individuals without VR.
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http://dx.doi.org/10.2147/NDT.S192231DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6404991PMC
March 2019