P-179: Identifying successful cognitive aging endophenotypes in the Central Valley of Costa Rica

Abstract

Background: Successful cognitive aging (SCA) is a genetically complex desirable trait. Gene identification will thus be facilitated through the delineation of cognitive endophenotypes, i.e., intermediate traits that are more direct expressions of single specific genes or a small number of genes. Strong delayed recall and psychomotor speed are both promising candidates for such endophenotypes. We looked at these functions in the offspring of very elderly (90+) nondemented (VEND) probands and two comparison groups from the Central Valley of Costa Rica (CVCR), a population with increased genetic homogeneity. Objective(s): To identify cognitive endophenotypes for SCA. Methods Delayed recall and psychomotor speed were assessed in 52 VEND probands from the CVCR and 76 of their aged 60+ year old offspring. Two CVCR comparison family groups were also assessed: 1) 24 very elderly demented (VED) probands and 43 of their 60+ year old offspring; 2) 31 young nondemented elderly (YND) probands and 67 of their 60+ year old siblings. Results: Using a random effects model controlling for age, sex, and education delayed recall was significantly better among VEND offspring than VED offspring (P<.05) and nominally better than YND siblings. Psychomotor speed was significantly better among VEND offspring then YND siblings (P<.05) and nominally better than VED offspring. Conclusions: These data offer preliminary evidence that delayed recall and psychomotor speed functions are useful endophenotypes for SCA.