title: Circulating insulin-like growth factor 1 and insulin-like growth factor binding protein-3 level in Alzheimer's disease: a meta-analysis.
abstract: It has been reported that the associations between circulating insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) and Alzheimer's disease (AD) are controversial. Thus, present meta-analysis was carried out to confirm the probable associations. We searched "PubMed", "Springer" and "Medline" databases using the term ("insulin-like growth factor-1" or "IGF-1" or "insulin-like growth factor binding protein-3" or "IGFBP-3") and ("Alzheimer's disease") until April 2016. Furthermore, standard mean differences (SMDs) were calculated. A total of seven reports involving 1342 percipients were pooled. SMDs were -0.25 (P = 0.22) and -0.33 (P = 0.08) for IGF-1 and IGFBP-3, respectively. Furthermore, the circulating IGF-1 levels in AD patients were lower than controls when studies with the difference of mean age ≤1 year (SMD -0.57, P = 0.007) or 2 years (SMD -0.58, P = 0.02) or difference of mean MMSE scores ≤10 scores (SMD -0.94, P < 0.00001), or studies from Europe (SMD -0.89, P < 0.00001) were excluded. In addition, the circulating IGFBP-3 levels in AD patients were lower than controls when studies with the difference of mean age ≤2 years (SMD -0.62, P = 0.006) or difference of mean MMSE scores ≤6 scores (SMD -0.48, P = 0.0004), 7 scores (SMD -0.58, P = 0.02), or 8 scores (SMD -0.80, P = 0.03) were excluded. Even though no significant difference of circulating IGF-1 and IGFBP-3 levels in AD patients comparing with controls was found in present meta-analysis, the current study provided the evidence that the circulating IGF-1 and IGFBP-3 level in AD patients were influenced by the difference of mean age as well as MMSE scores. Furthermore, circulating IGFBP-3 levels in AD patients may be decreased earlier than IGF-1.
authors.affiliation: Department of Neurology, Jingzhou Hospital, Tongji Medical College, Huazhong University of Science Technology, Renming Road No.1, Jingzhou, 434020, Hubei, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Hu
authors.affiliation: Hubei College of Chinese Medicines, Jingzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Neurology, Jingzhou Hospital, Tongji Medical College, Huazhong University of Science Technology, Renming Road No.1, Jingzhou, 434020, Hubei, China. 253465114@qq.com.
authors.forename: Daokai
authors.initials: D
authors.lastname: Gong
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism*; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male
chemical_list: C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I
keywords: Alzheimer’s disease; Cognitive impairment; Insulin-like growth factor binding protein-3; Insulin-like growth factor-1; Meta-analysis