Cognitive aging in persons with minimal amyloid-β and white matter hyperintensities

Substantial individual differences exist in the magnitude of the cognitive decline associated with normal aging. Potential contributors to this intersubject variability include white matter hyperintensities (WMH) and preclinical Alzheimer′s disease, evident as increased brain amyloid. This study examined whether older individuals with minimal evidence of WMH and/or brain amyloid-beta (seen on positron emission tomography with the Pittsburgh compound B radiotracer—PiB) still showed significant cognitive decrements compared to the young. Older individuals, conservatively screened for normal range performance on an extensive neuropsychological battery, underwent structural magnetic resonance imaging (MRI) and PiB scans and performed tests of information processing speed, working memory and inhibitory function. The elderly were divided into PiB(+) and PiB(−) groups based on radiotracer retention. There were no significant differences in cognitive performance between PiB(+) and PiB(−) elderly. However, both PiB groups performed significantly worse than did the young on cognitive testing. WMH burden in the same individuals was quantified by consensus ratings using a 10 point scale with a median split defining two groups, WMH(+) and WMH(−). There were no differences in cognitive performance between WMH(+) and WMH(−) individuals, but both WMH groups performed significantly worse than did the young. Older participants who were both PiB(−) and WMH(−) also performed significantly worse than did the young in all three cognitive domains. The present results suggest that normal-elderly individuals whose brain scans show minimal evidence of amyloid deposition or WMH, still demonstrate a major decrement in comparison to younger persons on measures of processing resources and inhibitory efficiency.     

A medial temporal lobe division of labor: Insights from memory in aging and early Alzheimer disease

Dual process theories of recognition memory posit that recollection and familiarity represent dissociable processes. Animal studies and human functional imaging experiments support an anatomic dissociation of these processes in the medial temporal lobes (MTL). By this hypothesis, recollection may be dependent on the hippocampus, while familiarity appears to rely on extrahippocampal MTL (ehMTL) structures, particularly perirhinal and lateral entorhinal cortices. Despite these findings, the dual process model and these anatomic mappings remain controversial, in part because the study of patients with lesions to the MTL has been limited and has revealed predominantly single dissociations. We examined measures of recollection and familiarity in three groups (normal older adults, amnesic‐mild cognitive impairment, Alzheimer's disease) in which these memory measures and the relative integrity of MTL structures are variable, thus enhancing our power to detect MTL‐memory relationships. Recollection and familiarity and volumes of hippocampus and ehMTL, defined as a region including entorhinal/perirhinal cortices and parahippocampus, were measured. Regression analyses revealed a stronger relationship of recollection with the hippocampus compared to ehMTL, while familiarity was more highly related to ehMTL compared to hippocampus. These results are consistent with a division of labor in the MTL and the dual process model. © 2010 Wiley‐Liss, Inc.     

Dietary patterns and their association with cardiovascular risk factors in a population undergoing lifestyle changes: The Strong Heart Study

Background and aimsRates of cardiovascular disease (CVD) are disproportionately high in American Indians (AI), and changes in lifestyle may be responsible. It is not known whether diverse dietary patterns exist in this population and whether the patterns are associated with CVD risk factors. This article describes the relationships between dietary patterns and CVD risk factors in this high-risk population.Methods and resultsNutrition data were collected via food frequency questionnaire from 3438 Strong Heart Study (SHS) participants, ≥ age 15 y. All participants were members of 94 extended families. The final sample consisted of 3172 men and women. Diet patterns were ascertained using factor analysis with the principal component factoring method. We derived four predominant dietary patterns: Western, traditional AI/Mexican, healthy, and unhealthy. Participants following the Western pattern had higher LDL cholesterol (LDL-C) (p < 0.001), slightly higher systolic blood pressure (BP) (p < 0.001), lower HDL cholesterol (HDL-C) (p < 0.001), and slightly lower homeostasis model assessment estimates of insulin resistance (HOMA-IR) in the lowest vs. highest deciles of adherence to this pattern (p < 0.001). The traditional diet was associated with higher HDL-C (p < 0.001), but higher body mass index (BMI) (p < 0.001) and HOMA-IR (p < 0.001). Followers of the healthy pattern had lower systolic BP, LDL-C, BMI, and HOMA-IR in increasing deciles (p < 0.001). The unhealthy pattern was associated with higher LDL-C.ConclusionsDietary patterns reflect the changing lifestyle of AI and several of the patterns are associated with CVD risk factors. Evolving methods of food preparation have made the traditional pattern less healthy.     

The relationship of self-rated health with functional status,toxicity and mortality: Results of a prospective pilot study of older patients with newly-diagnosed cancer

ObjectivesTo determine the association between self-rated health (SRH) and functional status, comorbidity, toxicity of treatment and mortality in older patients with newly-diagnosed cancer.Materials and MethodsPatients aged 65 and over, newly diagnosed were recruited at the Jewish General Hospital, Montreal, Canada. SRH and functional status [instrumental activities of daily living (IADL), basic activities of daily living (ADL), Eastern Cooperative Oncology Group performance status (ECOG PS), frailty markers and number of comorbid conditions] were evaluated prior to the start of treatment, and at 3, 6 and 12 months (SRH only). Treatment toxicity and mortality data were abstracted from the chart. Logistic regression was also used to examine the relationship between functional status, comorbidity and SRH at baseline. Logistic and Cox regression were used to examine the association between baseline SRH and treatment toxicity/time to death.ResultsThere were 112 participants enrolled on this study (median age 74.1). At baseline, 74 patients (66.1%) had a good SRH and 38 patients (33.9%) had poor SRH. Only an increasing number of comorbid conditions was associated with poor SRH at baseline in both univariate and multivariable analysis. We found no association between SRH and toxicity or mortality.ConclusionA substantial proportion had poor SRH prior to and during cancer treatment. An increasing number of comorbidities was associated with poor SRH at baseline. SRH did not predict toxicity or mortality. Attention to comorbid conditions in older patients with cancer is warranted considering their impact on SRH in this population.     

Of Steeplejacks and Bureaucrats

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