A meta-analysis of cerebrospinal fluid visinin-like protein-1 in alzheimer’s disease patients relative to healthy controls and mild cognitive impairment patients

OBJECTIVE To compare cerebrospinal fluid visinin-like protein-1 (CSF VLP-1) in alzheimer`s disease (AD) with that in healthy controls and mild cognitive impairment (MCI) patients and find out possible sources of heterogeneity. METHODS "Visinin-like protein-1" and "alzheimer`s disease" were employed to search "PubMed", "Springer" and "Medline" databases until July 2016 and standard mean difference (Std.MD) was calculated. Besides, subgroup analysis and meta-regression were performed to explore the possible heterogeneity sources. RESULTS Seven studies involved 1151 participants were pooled. The CSF VLP-1 in AD patients was higher than that in healthy controls and MCI patients (pooled Std.MD=0.81, 95% CI: [0.47, 1.16], p<0.00001). As shown by subgroup analysis, population variations were one of heterogeneity sources. Meta-regression revealed that Hedges`s g of CSF VLP-1 was correlated with Std.MD of t-tau (r=0.560, p=0.006) and amyloid beta42 (r=-0.386, p=0.013). CONCLUSION The CSF VLP-1 in AD patients is higher than that in healthy controls and MCI patients. The changes of VLP-1 in AD patients relative to healthy controls and MCI patients is less pronounced than that of core biomarkers, such as amyloid beta42, t-tau and p-tau. Population variations, increasing t-tau and decreasing amyloid beta42 in AD patients relative to healthy controls and MCI patients were the main sources of heterogeneity.