title: Butyrylcholinesterase K variant and Alzheimer's disease risk: a meta-analysis.
abstract: BACKGROUND
  Although many studies have estimated the association between the butyrylcholinesterase (BCHE) K variant and Alzheimer's disease (AD) risk, the results are still controversial. We thus conducted this meta-analysis.
  
  
  METHODS
  We searched NCBI, Medline, Web of Science, and Embase databases to find all eligible studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association.
  
  
  RESULTS
  We found a significant association between BCHE K variant and AD risk (OR=1.20; 95% CI 1.03-1.39; P=0.02). In the stratified analysis by ethnicity, we observed a significant association between BCHE K variant and AD risk in Asians (OR=1.32; 95% CI 1.02-1.72; P=0.04). However, no significant association between BCHE K variant and AD risk in Caucasians was found (OR=1.14; 95% CI 0.95-1.37; P=0.16). When stratified by the age of AD onset, we found that late-onset AD (LOAD) was significantly associated with BCHE K variant (OR=1.44; 95% CI 1.05-1.97; P=0.02). No significant association between BCHE K variant and early-onset AD (EOAD) risk was observed (OR=1.16; 95% CI 0.89-1.51; P=0.27). Compared with non-APOE ε4 and non-BCHE K carriers, no significant association between BCHE K variant and AD risk was found (OR=1.11; 95% CI 0.91-1.35; P=0.30). However, APOE ε4 carriers showed increased AD risk in both non-BCHE K carriers (OR=2.81; 95% CI 1.75-4.51; P=0.0001) and BCHE K carriers (OR=3.31; 95% CI 1.82-6.02; P=0.0001).
  
  
  CONCLUSIONS
  The results of this meta-analysis indicate that BCHE K variant might be associated with AD risk.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Zongcheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Yuren
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Yangsen
authors.initials: Y
authors.lastname: Du
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Dandan
authors.initials: D
authors.lastname: Xiao
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Youchao
authors.initials: Y
authors.lastname: Deng
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan, China (mainland).
authors.forename: Jinlian
authors.initials: J
authors.lastname: Wang
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000201:enzymology / Q000208:ethnology / Q000235:genetics*; D053327:Apolipoprotein E4 / Q000235:genetics; D044466:Asian People / Q000235:genetics; D002091:Butyrylcholinesterase / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D017594:Publication Bias; D012306:Risk; D012680:Sensitivity and Specificity; D044465:White People / Q000235:genetics
chemical_list: D053327:Apolipoprotein E4; D002091:Butyrylcholinesterase