title: APOE genotype and age modifies the correlation between cognitive status and metabolites from hippocampus by a 2D (1)H-MRS in non-demented elders.
abstract: Purpose. To examine the associations among age, Apolipoprotein E (APOE) genotype, metabolic changes in the hippocampus detected by 2D (1)H magnetic resonance spectroscopy (MRS), and neuropsychological measures of cognition in non-demented elders. Materials and Methods. We studied a cohort of 16 cognitively normal controls (CN) and 11 amnestic mild cognitive impairment (aMCI) patients between 66 and 88 years old who were genotyped for APOE genetic polymorphism. Measurements of 2D(1)H-MRS metabolites were obtained in the hippocampus region. Adjusting by age among all subjects, the association between metabolic changes and cognitive function was measured by Spearman partial rank-order correlation. The effect of APOE status was measured by separating the subjects into APOE genotype subgroups, including the APOEε4 carriers and APOEε4 non-carriers. Results. In contrast to the CN group matched with age, gender, and education, aMCI patients showed increased myo-inositol (mI)/Creatine (Cr) ratio only in the right hippocampus. No differences were noted on N-acetylaspartate (NAA)/Cr and mI/NAA from bilateral hippocampus, and so was mI/Cr ratio in left hippocampus between aMCI and CN. The mI/Cr ratio from the right hippocampus in non-demented elders was negatively correlated with Montreal Cognitive Assessment (MoCA) scores. Whether ε4 genotype or age was added as a covariate, none of the correlation effects remained significant. Additionally, adjusting for age and APOE genotype together, there was no significant correlation between them. Conclusion. Since the higher mI/Cr from the right hippocampus of the patients with aMCI than those from CN, the mI/Cr could be a more specific predictor of general cognitive function in aMCI patients. There is an association between higher mI/Cr in right hippocampus and worse cognitive function for the non-demented older adults, and the correlation could be modified by APOE status and age. That provided a window on objectively understanding the mechanism between the brain metabolites and the influence factors in non-demented elders.
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Yin
authors.affiliation: Department of Neurology, Affiliated Drum Tower Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Renyuan
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Yu
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Aibin
authors.initials: A
authors.lastname: Guo
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Geriatrics, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Mingmin
authors.initials: M
authors.lastname: Huang
authors.affiliation: Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Chuanshuai
authors.initials: C
authors.lastname: Tian
authors.affiliation: Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xu
keywords: 2D1H-MRS metabolites; APOE genotype; Age; Amnestic mild cognitive impairment; Hippocampus