Age-associated cognitive changes in community dwelling adults

尽管有证据表明维生素D水平低与认知能力下降之间存在关联，但维生素D受体（VDR）和巨galin基因多态性在纵向认知变化中的作用尚不清楚。利用巴尔的摩老龄化纵向研究中702名参与者的数据，我们研究了VDR rs11568820 （CdX-2:T/C）、rs1544410 （BsmI:G/A）、rs7975232 （ApaI:A/C）、rs731236 （TaqI:G/A）和Megalin （rs3755166:G/A、rs2075252:C/T、rs4668123:C/T）基因的单核苷酸多态性（snp）与认知表现变化的关系。在潜在分类、单倍型和回归分析中，我们发现Megalin1单核苷酸多态性单倍型（GCC）与女性在言语记忆、即时回忆（CVLT-List A）方面的下降较大，而与男性在延迟回忆（CVLT-Delayed recall）方面的下降较慢有关。我们还发现，Megalin SNP rs3755166:G/A与两性整体认知能力和男性言语记忆能力的较大下降有关。这些结果表明，维生素D受体和meggalin多态性改变了与年龄相关的认知衰退。

Although there is evidence for an association between low levels of Vitamin D and cognitive decline, the role of Vitamin D receptor (VDR) and the megalin gene polymorphism's link with longitudinal cognitive change has been unclear. Using data from 702 participants in the Baltimore Longitudinal Study of Aging, we examined the associations of single nucleotide polymorphisms (SNPs) for VDR rs11568820 (CdX-2:T/C), rs1544410 (BsmI:G/A), rs7975232 (ApaI:A/C), rs731236 (TaqI:G/A), and Megalin (rs3755166:G/A; rs2075252:C/T; rs4668123:C/T) genes with changes in cognitive performance. In latent class, haplotype, and regression analyses we found the Megalin1 single nucleotide polymorphism haplotype (GCC) was related to greater decline among women in verbal memory, immediate recall (CVLT-List A), but slower decline among men in delayed recall (CVLT-Delayed recall). We also found that the Megalin SNP rs3755166:G/A was associated with greater decline in global cognition in both sexes combined and in verbal memory in men. These results suggest that the vitamin D receptor and the megalin polymorphism modifies age-related cognitive decline. We hypothesized that greater hearing loss was associated with lower cognitive test scores on tests of memory and executive function. In a cross-sectional cohort of 347 participants >= 55 years from the Baltimore Longitudinal Study of Aging without mild cognitive impairment or dementia we examined the association of hearing loss and cognitive performance. Participants had audiometric and cognitive testing performed in 1990-1994. Hearing loss was defined by an average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear. Cognitive testing consisted of a standardized neurocognitive battery incorporating tests of mental status, memory, executive function, processing speed, and verbal function. Regression models were used to examine the association between hearing loss and cognition while adjusting for confounders. Greater hearing loss was significantly associated with lower scores on measures of mental status (Mini-Mental State Exam), memory (Free Recall), and executive function (Stroop Mixed, Trail Making B). These results were robust to analyses accounting for potential confounders, nonlinear effects of age, and exclusion of individuals with severe hearing loss. The reduction in cognitive performance associated with a 25 dB hearing loss was equivalent to the reduction associated with an age difference of 6.8 years. Hearing loss is independently associated with lower scores on tests of memory and executive function. Previous studies showed that negative self-stereotypes detrimentally affect the cognitive performance of marginalized group members; however, these findings were confined to short-term experiments. We examined whether stereotypes predicted memory over time, which had not been previously examined. We also considered whether self-relevance increased the influence of stereotypes on memory over time. In data from multiple waves of memory performance from 395 participants in the Baltimore Longitudinal Study of Aging, we examined individual growth models as a function of negative age stereotypes. We found that those with more negative age stereotypes demonstrated significantly worse memory performance over 38 years than those with less negative age stereotypes. The decline in memory performance for those aged 60 and above was 30.2% greater for the more negative age stereotype group than for the less negative age stereotype group. Also, the impact of age stereotypes on memory was significantly greater among those for whom the age stereotypes were self-relevant. This study shows that the adverse influence of negative self-stereotypes on cognitive performance is not limited to a short-term laboratory effect. Rather, the findings demonstrate, for the first time, that stereotypes also predict memory performance over an extended period in the community.