Cardiovascular risk and memory in non-demented elderly women

Brain BDNF levels are dependent on cerebrovascular endothelium-derived nitric oxide

Scientific evidence continues to demonstrate a link between endothelial function and cognition. Besides, several studies have identified a complex interplay between nitric oxide (NO) and brain-derived neurotrophic factor (BDNF), a neurotrophin largely involved in cognition. Therefore, this study investigated the link between cerebral endothelium-derived NO and BDNF signaling. For this purpose, levels of BDNF and the phosphorylated form of endothelial NO synthase at serine 1177 (p-eNOS) were simultaneously measured in the cortex and hippocampus of rats subjected to either bilateral common carotid occlusion (n = 6), physical exercise (n = 6) or a combination of both (n = 6) as experimental approaches to modulate flow-induced NO production by the cerebrovasculature. Tropomyosin-related kinase type B (TrkB) receptors and its phosphorylated form at tyrosine 816 (p-TrkB) were also measured. Moreover, we investigated BDNF synthesis in brain slices exposed to the NO donor glyceryl trinitrate. Our results showed increased p-eNOS and BDNF levels after exercise and decreased levels after vascular occlusion as compared to corresponding controls, with a positive correlation between changes in p-eNOS and BDNF (r = 0.679). Exercise after vascular occlusion did not change levels of these proteins. Gyceryl trinitrate increased proBDNF and BDNF levels in brain slices, thus suggesting a possible causal relationship between NO and BDNF. Moreover, vascular occlusion, like exercise, resulted in increased TrkB and p-TrkB levels, whereas no change was observed with the combination of both. These results suggest that brain BDNF signaling may be dependent on cerebral endothelium-derived NO production.

Haptoglobin 1-1 genotype is associated with poorer cognitive functioning in the elderly with type 2 diabetes

OBJECTIVE

Haptoglobin (Hp) genotype (Hp 1-1, 1-2, or 2-2) is associated with risk for type 2 diabetes complications, but its relationship with cognitive compromise, a growing concern in type 2 diabetes, has rarely been studied. This study investigated whether Hp genotype is associated with cognitive function in cognitively normal elderly diabetic subjects.

RESEARCH DESIGN AND METHODS

Relationships of Hp genotype with episodic memory, semantic categorization, attention/working memory and executive function, and an overall cognitive score were examined in subjects from the Israel Diabetes and Cognitive Decline (IDCD) study.

RESULTS

In the present analysis, 812 subjects participated (84 with Hp 1-1, 335 with Hp 1-2, and 393 with Hp 2-2 genotypes). Average was 72.9 years of age (SD 4.7), and Mini-Mental State Exam (MMSE) was 28.0 (SD 1.8). Compared with subjects with Hp 1-2 genotype, Hp 1-1 subjects performed significantly worse in semantic categorization (F=7.03; P=0.008) and the overall cognitive score (F=5.57; P=0.02). A separate stepwise multiple regression analysis demonstrated that compared with subjects with Hp 2-2 genotype, Hp 1-1 subjects performed significantly worse in semantic categorization (F=4.18; P=0.04) and the overall cognitive score (F=4.70; P=0.03). The contribution of cardiovascular risk factors to cognition was significantly higher in subjects with Hp 1-1 genotype compared with Hp 2 carriers (Hp 1-2 and Hp 2-2) in the semantic categorization (P=0.009) and attention/working memory (P=0.002) cognitive domains.

CONCLUSIONS

Compared with Hp 2 carriers, those with Hp 1-1 genotype present lower cognitive performance. Stronger relationships between cardiovascular risk factors and cognition in the latter group may suggest an underlying vascular mechanism.

Effect of leisure activities on inflammation and cognitive function in an aging sample

Cardiovascular disease risk factors (CVDRFs) increase the risk of dementia. The purpose of this study was to examine whether leisure activities (mental, physical, and social activities) modified the effect of CVDRFs on inflammatory markers and cognitive function in middle and old age. A secondary-data analysis study was conducted using data from 405 middle-age participants (40-59 years) and 342 old-age participants (60-84 years) who participated in the Survey of Midlife Development in the United States (MIDUS). CVDRFs were obtained from a combination of self-report medical history and blood-based biomarkers. Three CVDRF groups (≤1, 2, and ≥3 CVDRFs) were identified. More CVDRFs were significantly associated with higher levels of inflammatory markers in both age groups, and associated with lower levels of executive function (EF) in the old age group. CVDRFs were not related to the frequency of leisure activities in either age group. After controlling for covariates, higher levels of physical activities were significantly associated with lower levels of inflammatory markers, and higher levels of mental activities were associated with higher levels of cognitive function. In the old age group, physical activities also moderated the effect of CVDRFs on episodic memory (EM), and mental activities moderated the effect of CVDRFs on interleukin-6 (IL-6). Multiple CVDRFs may be associated with poorer cognitive function and higher inflammatory markers, but middle-age and older adults with CVDRFs may not engage in frequent physical and cognitive activities that may be protective. It is important to develop strategies to facilitate engagement in these activities from midlife.

Co-morbidity and drug treatment in Alzheimer's disease. A cross sectional study of participants in the dementia study in northern Norway

Background

Inappropriate medical treatment of co-morbidities in Alzheimer's disease (AD) is an increasing concern in geriatric medicine. The objective of this study was to compare current drug use related to co-morbidity between individuals with a recent diagnosis of AD and a cognitively healthy control group in a population based clinical trial in Northern Norway.

Methods

Setting: Nine rural municipalities with 70 000 inhabitants in Northern Norway.

Participants: Participants with and without AD recruited in general practice and by population based screening.

187 participants with a recent diagnosis of AD were recruited among community dwellers. Of 791 respondents without cognitive symptoms, 500 were randomly selected and invited to further clinical and cognitive testing. The final control group consisted of 200 cognitively healthy individuals from the same municipalities. Demographic characteristics, data on medical history and current medication were included, and a physical and cognitive examination was performed. The statistical analyses were carried out by independent sample t-test, chi-square, ANCOVA and logistic regression.

Results

A co-morbidity score was significantly higher in AD participants compared to controls. The mean number of drugs was higher for AD participants compared to controls (5.1 ± 3.6 and 2.9 ± 2.4 respectively, p < 0.001 age and gender adjusted), also when adjusted for co-morbidity. AD participants used significantly more anticholinergic, sedative and antidepressant drugs. For nursing home residents with AD the mean number of drugs was significantly higher compared to AD participants living at home (6.9 ± 3.9 and 4.5 ± 3.3, respectively, p < 0.001).

Conclusions

AD participants were treated with a significantly higher number of drugs as compared to cognitively healthy controls, even after adjustment for co-morbidity. An inappropriate use of anticholinergic and sedative drugs was identified, especially among nursing home residents with AD. The drug burden and the increased risk of adverse reactions among individuals suffering from AD need more attention from prescribing doctors.

Evaluating cognition in an elderly cohort via telephone assessment

OBJECTIVE

Longitudinal neuropsychological assessment provides the opportunity to observe the earliest transition to cognitive impairment in healthy, elderly individuals. We examined the feasibility, and its comparability to in-person assessment, of a telephone administered battery of established neuropsychological measures of cognitive functioning in healthy, elderly women.

METHODS

Fifty-four women (age = 79 +/- 7.7; education = 15.4 +/- 3.3) who were in self-reported good health were recruited from senior centers and other community sources. A two-way cross-over design was used in which participants were randomly assigned to receive either (1) in-person neuropsychological assessment followed by telephone assessment and (2) telephone assessment followed by in-person assessment, separated by approximately 4 weeks. Linear regression models were used to determine whether there were performance differences by method (in-person vs. telephone), and equivalence testing assessed comparability of the two methods.

RESULTS

There were no statistically significant differences in performance between in-person and telephone assessments on most neuropsychological tests, with the exception of digit span backward, Oral Trail Making Test Part A, and delayed recall on the SRT, the latter likely related to non-comparable exposure (6-trials in-person vs. 3-trials telephone). Equivalence testing differences fell in the pre-specified clinical equivalence zones, providing evidence of comparability of the two methods.

CONCLUSIONS

These pilot data support telephone administration of a neuropsychological battery that yields comparable performance to in-person assessment with respect to most instruments. Significant differences in scores on some measures suggest care should be taken in selecting specific measures used in a neuropsychological battery administered by telephone.

Ten-year change in plasma amyloid beta levels and late-life cognitive decline

BACKGROUND

Plasma levels of amyloid beta peptide (Abeta) are potential biomarkers of early cognitive impairment and decline and of Alzheimer disease risk.

OBJECTIVE

To relate midlife plasma Abeta measures and 10-year change in plasma Abeta measures since midlife to late-life cognitive decline.

DESIGN

Prospective study of a population-based sample.

SETTING

Academic research.

PARTICIPANTS

Plasma Abeta40 and Abeta42 levels were measured in 481 Nurses' Health Study participants in late midlife (mean age, 63.6 years) and again 10 years later (mean age, 74.6 years). Cognitive testing also began 10 years after the initial blood draw. Participants completed 3 repeated telephone-based assessments (mean span, 4.1 years). Multivariable linear mixed-effects models were used to estimate relations of midlife plasma Abeta40 to Abeta42 ratios and Abeta42 levels to late-life cognitive decline, as well as relations of 10-year change in Abeta40 to Abeta42 ratios and Abeta42 levels to cognitive decline.

MAIN OUTCOME MEASURES

The 3 primary outcomes were the Telephone Interview for Cognitive Status (TICS) findings, a global score averaging the results of all tests (TICS, immediate and delayed verbal recall, category fluency, and attention), and a verbal memory score averaging the results of 4 tests of verbal recall.

RESULTS

Higher midlife plasma Abeta40 to Abeta42 ratios were associated with worse late-life decline on the global score (P = .04 for trend). Furthermore, increase in Abeta40 to Abeta42 ratios since midlife predicted greater decline in the global score (P = .03 for trend) and in the TICS (P = .02 for trend). There was no association of cognitive decline with midlife plasma Abeta42 levels alone or with change in Abeta42 levels since midlife.

CONCLUSION

In this large community-dwelling sample, higher plasma Abeta40 to Abeta42 ratios in late midlife and increases in Abeta40 to Abeta42 ratios 10 years later were significantly associated with greater decline in global cognition at late life.