Abstract: ［Abstract］〓Objective〖HTSS〗〓To investigate the predictive value of apolipoprotein E（APOE） gene polymorphisms and homocysteine(Hcy) on poststroke depression in the elderly. 
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓A total of 109 stroke patients admitted were selected and divided into stroke group(65 cases) and poststroke depression group(44 cases) according to whether the patient had depression. Both groups were tested for APOE polymorphisms(including genotype distribution and allele ε2, ε3, ε4 frequencies) and serum Hcy levels. The genotype distributions of ε2/ε2, ε2/ε3, ε2/ε4, ε3/ε3, ε3/ε4, ε4/ε4, the frequencies of alleles ε2, ε3, ε4, serum Hcy levels were compared between the two groups. Different genotypes were calculated to predict the sensitivity of poststroke depression in the elderly. The sensitivity of poststroke depression was plotted and the receiver operating characteristic(ROC) curve was plotted for serum Hey to predict poststroke depression.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The genotypes of the two groups were most common with ε3/ε3, and the distribution of the six different genotypes was not statistically significant(P＞005). There was no significant difference in the frequency of ε2 and ε3 gene between the two groups(P＞005). The frequency of ε4 gene in the poststroke depression group was higher than that in the stroke group(P＜005). Among different genotypes, the ε4/ε4 had the highest sensitivity of 83.33%(5/6) to predict poststroke depression. The serum Hcy levels in the poststroke depression group were higher than those in the stroke group(P＜005). There were no significant difference in serum Hcy levels in different genotypes between the two groups(P＞005). The serum Hcy level predicts ROC curve area for poststroke depression in the elderly with 0.744, a sensitivity of 64.70%, a specificity of 81.20%, and a critical value of 18.455 μmol/L.
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓The serum homocysteine and APOE gene polymorphisms can be used as predictors of poststroke depression in elderly stroke patients and provide references for elderly stroke patients to reduce the incidence of poststroke depression.

Key words: stroke, depression, apolipoproteins E, cysteine