title: Alzheimer-associated urine neuronal thread protein level increases with age in a healthy Chinese population.
abstract: Alzheimer-associated neuronal thread protein (AD7c-NTP) has been found to be a biomarker for Alzheimer's disease (AD) with elevated levels in the cerebrospinal fluid and urine from AD patients in the early stage of the disease. Whether the urine level of AD7c-NTP in healthy people is age-related is still unclear. We aimed to measure the level of urine AD7c-NTP in a healthy Chinese population of different ages. Urine samples of 294 subjects were collected from the Department of Health Examination Center at Xuanwu Hospital of Capital Medical University, China. The samples were divided into five groups by age: Group 1 (20-29 years), Group 2 (30-39 years), Group 3 (40-49 years), Group 4 (50-59 years) and Group 5 (⩾ 60 years). The Mini Mental State Examination and Montreal Cognitive Assessment were carried out. The level of AD7c-NTP in the urine specimen was detected by enzyme-linked immunosorbent assay. The urine AD7c-NTP levels in Group 1, 2, 3, 4 and 5 were 0.3012 ± 0.2373, 0.3702 ± 0.2422, 0.3914 ± 0.2442, 0.4844 ± 0.2908 and 0.5880 ± 0.2638 ng/ml (mean ± standard error of the mean), respectively. The urine AD7c-NTP levels among the five groups differed significantly (F=6.181, p=0.00). Females had a higher urine AD7c-NTP content than males, and the urine AD7c-NTP level increased with age (r=0.28, p=0.00). To our knowledge this study is the first to show that urine AD7c-NTP level increases with age in a healthy Chinese population without cognitive dysfunction. This study suggests that different cut-off values aimed at different age groups should be established for diagnosing cognitive impairments in clinical practice.
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China; Department of Geriatrics, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Ma
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China. Electronic address: rong_wang72@aliyun.com.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Han
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China.
authors.forename: Jingshuang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Dong
authors.affiliation: Central Laboratory, Xuanwu Hospital of Capital Medical University, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, #45 Changchun Street, Xicheng District, Beijing 100053, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Medical Center, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Youqin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Medical Center, Xuanwu Hospital of Capital Medical University, Beijing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chu
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000652:urine*; D044466:Asian People; D003071:Cognition / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000652:urine*; D009483:Neuropsychological Tests; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: C109804:AD7c-NTP; D009419:Nerve Tissue Proteins
keywords: Age; Alzheimer-associated neuronal thread protein; ELISA; Urine