Haemoglobin Concentration and Cognitive Ability in the Aberdeen Children of the 1950s

Introduction

Haemoglobin concentrations decrease with age. Abnormally low and high haemoglobin concentrations are associated with reduced cognition; however, the evidence for these associations in cohort data is limited. This study aims to assess the relationship between haemoglobin concentration and cognition in a well-characterised cohort of older adults.

Methods

Two hundred and fifty-two healthy participants were drawn from the Aberdeen Children of the 1950s cohort, aged between 59 to 65 years. Participants underwent cognitive tests of processing speed, memory, verbal and nonverbal reasoning, and language ability and these were used to construct a global cognitive score, g, using principal component analysis. Haemoglobin concentration in the blood was measured concurrently. Hierarchical multiple regression models were constructed assessing the relationship between haemoglobin concentration and each cognitive measure and these were corrected for age, sex, education, C-reactive protein, hypertension, and body mass index.

Results

Significant linear association between haemoglobin concentration and nonverbal reasoning demonstrated that low haemoglobin levels are associated with lower scores. A quadratic relationship was found for haemoglobin concentration and immediate memory scores in which low and high haemoglobin levels were associated with lower scores.

Conclusions

Haemoglobin concentration was found to have a significant linear association with nonverbal reasoning scores and a significant quadratic association with memory scores. The results from this study help to understand the association between haemoglobin and different aspects of cognition.

Imprinting methylation predicts hippocampal volumes and hyperintensities and the change with age in later life

Epigenetic imprinting is important for neurogenesis and brain function. Hippocampal volumes and brain hyperintensities in late life have been associated with early life circumstances. Epigenetic imprinting may underpin these associations. Methylation was measured at 982 sites in 13 imprinted locations in blood samples from a longitudinal cohort by bisulphite amplicon sequencing. Hippocampal volumes and hyperintensities were determined at age 64y and 72y using MRI. Hyperintensities were determined in white matter, grey matter and infratentorial regions. Permutation methods were used to adjust for multiple testing. At 64y, H19/IGF2 and NESPAS methylation predicted hippocampal volumes. PEG3 predicted hyperintensities in hippocampal grey matter, and white matter. GNASXL predicted grey matter hyperintensities. Changes with age were predicted for hippocampal volume (MEST1, KvDMR, L3MBTL, GNASXL), white matter (MEST1, PEG3) and hippocampal grey matter hyperintensities (MCTS2, GNASXL, NESPAS, L3MBTL, MCTS2, SNRPN, MEST1). Including childhood cognitive ability, years in education, or socioeconomic status as additional explanatory variables in regression analyses did not change the overall findings. Imprinting methylation in multiple genes predicts brain structures, and their change over time. These findings are potentially relevant to the development of novel tests of brain structure and function across the life-course, strategies to improve cognitive outcomes, and our understanding of early influences on brain development and function.

Circulating asymmetric dimethylarginine and cognitive decline: A 4-year follow-up study of the 1936 Aberdeen Birth Cohort

BACKGROUND

The underlying mechanisms leading to dementia and Alzheimer's disease (AD) are unclear. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, may be associated with cognitive decline, but population-based evidence is lacking.

METHODS

Change in cognitive performance was assessed in participants of the Aberdeen Birth Cohort of 1936 using longitudinal Raven's progressive matrices (RPM) between 2000 and 2004. Multiple linear regression was used to estimate the association between ADMA concentrations in 2000 and change in cognitive performance after adjustment for potential confounders.

RESULTS

A total of 93 participants had complete information on cognitive performance between 2000 and 2004. Mean plasma ADMA concentrations were approximately 0.4 μmol/L lower in those participants with stable or improved RPM scores over follow-up compared with participants whose cognitive performance worsened. In confounder-adjusted analysis, one SD (0.06 μmol/L) increase in ADMA at 63 years of age was associated with an average reduction in RPM of 1.26 points (95% CI 0.14-2.26) after 4 years.

CONCLUSION

Raised plasma ADMA concentrations predicted worsening cognitive performance after approximately 4 years in this cohort of adults in late-middle age. These findings have implications for future research, including presymptomatic diagnosis or novel therapeutic targets for dementia and AD.

The epidemiology of polypharmacy in a large cohort with linked health records in Scotland

Background

Our understanding of the potential harm of taking multiple medications in older, multi-morbid populations is limited. We aimed to investigate the prevalence of polypharmacy and its association with hospitalisation in a large cohort with linked health data.

Methods

Prescription data and hospital admission records of the Aberdeen Children of the 1950s (ACONF) Cohort were extracted from the National Health Services Scotland database and linked from 2011-2016. We estimated polypharmacy by measuring monthly drug exposure for 1) total number of prescribed medications and 2) total number of defined daily doses (DDDs). Cox proportional hazard models (adjusted for demographics, socioeconomic circumstances and health conditions) were used to examine the association of polypharmacy and hospitalisation.

Results

Prescription records were linked for 8,713 cohort members. Mean age at baseline was 58.5 years (SD = 1.5) and 50% were female. 1,994 individuals (23%) had at least one health condition and 8% of population had multimorbidity. The proportion of cohort with polypharmacy assessed using taking 5+ medications and taking 5+ DDDs at baseline were 12.7% (female=12.6% vs male=12.7%, P = 0.179), and 15.5% (female=13.8% vs male=17.1%, P < 0.001) respectively. Of all the cohort, 4,365 admitted to hospital (mean follow-up of 3.5 years, total 30,269 person-years). Adjusted hazard ratios for hospitalisation were 1.51 (95 % CI 1.39,1.64, P < 0.001) for polypharmacy measured by number of medications and 1.40 (95 % CI 1.29,1.51 P < 0.001) for polypharmacy estimated by number of daily doses.

Conclusions

Polypharmacy is independently associated with increased risk of hospitalisation. This association could signify polypharmacy as a risk factor and a marker of poor outcome. Data linkage can generate evidence-based information for future policy and health services to improve polypharmacy measurement and management.

Key messages

Data linkage is a cost effective and contemporary return on the investment in data collection and research in public health. Improvement in evidence to better understand the relationship between polypharmacy and health outcomes should be a priority to optimise treatment in older people with various chronic conditions.

Brain hyperintensity location determines outcome in the triad of impaired cognition, physical health and depressive symptoms: A cohort study in late life

PURPOSE OF THE STUDY

Brain hyperintensities, detectable with MRI, increase with age. They are associated with a triad of impairment in cognitive ability, depression and physical health. Here we test the hypothesis that the association between hyperintensities and cognitive ability, physical health and depressive symptoms depends on lesion location.

DESIGN AND METHODS

244 members of the Aberdeen 1936 Birth Cohort were recruited to this study. 227 participants completed brain MRI and their hyperintensities were scored using Scheltens's scale. 205 had complete imaging, cognitive, physical health and depressive symptom score data. The relationships between hyperintensity location and depressive symptoms, cognitive ability and physical health were examined by correlation and structural equation analysis.

RESULTS

We found that depressive symptoms correlated with hyperintensity burden in the grey matter (r=0.14, p=0.04) and infratentorial regions (r=0.17, p=0.01). Infratentorial hyperintensities correlated with reduced peak expiratory flow rate (r=-0.26, p<0.001) and impaired gait (r=0.13, p=0.05). No relationship was found between white matter and periventricular (supratentoral) hyperintensities and depressive symptoms. Hyperintensities in the supratentorial and infratentorial regions were associated with reduced cognitive performance. Using structural equation modelling we found that the association between hyperintensities and depressive symptoms was mediated by negative effects on physical health and cognitive ability.

CONCLUSIONS

Hyperintensities in deep brain structures are associated with depressive symptoms, mediated via impaired physical health and cognitive ability. Participants with higher cognitive ability and better physical health are at lower risk of depressive symptoms.

PI3K Pathway Activation in Breast Cancer Is Associated with the Basal-Like Phenotype and Cancer-Specific Mortality

Background: Current biological therapies for breast cancer are tailored to steroid hormone (ER, PR) and HER2 receptor status. Understanding the biological basis of resistance to current targeted therapies and the identification of new potential therapeutic targets is an ongoing challenge. The PI3K pathway is altered in a high proportion of breast cancers and may be associated with specific phenotypes and therapeutic resistance. We undertook an integrative study of mutational, copy number and expression analysis of key regulators of the PI3K pathway in a cohort of 292 invasive breast cancer patients with known treatment outcomes.Material and Methods: Mutations in 3 "hotspots" in exons 9 and 20 of the PIK3CA gene were determined by sequencing and PIK3CA gene copy number by qPCR. PTEN loss and Akt activation i.e. pAkt (Ser473) were assessed by immunohistochemistry using tissue microarrays. Cores were scored by 2 independent observers blinded to clinicopathological data and patient outcome and a histoscore calculated by multiplying the percent positive cells and staining intensity in a range 0-3. Standard statistical tests were applied to assess relationship between the measured parameters and patient outcome.Results: Alterations identified included PIK3CA mutations (12/168 i.e. 7%), PIK3CA copy number gain (28/209 i.e. 14%), PTEN loss (73/258 i.e. 28%) and AKT activation (62/258 i.e. 24%). Overall at least one parameter was altered in 72% i.e. 139 of 193 assessable primary breast cancers. PI3K pathway activation was significantly associated with ER negative (P=0.0008) and PR negative (P=0.006) status, high tumor grade (P=0.032) and a "basal-like" phenotype (P=0.01), where 92% (25/27) of tumors had an altered pathway. In univariate analysis PI3K pathway aberrations were associated with death from breast cancer however this relationship was not maintained in multivariate analysis. No association was identified between an activated pathway and outcome in tamoxifen- or chemotherapy-treated patients.Discussion: We conclude that &gt;70% of breast cancers have an alteration in at least one component of the PI3K pathway and this might be exploited to therapeutic advantage especially in "basal-like" cancers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2123.

Akinetic mutism and mixed transcortical aphasia following left thalamo-mesencephalic infarction

A 54-year-old man developed somnolent akinetic mutism and acute mixed transcortical aphasia following a left thalamo-mesencephalic infarction. He also exhibited behavioural changes, namely apathy, slowness, lack of spontaneity, disinhibition, perseveration, gait apraxia and incontinence consistent with frontal lobe dysfunction. Presumably the akinetic mutism and language dysfunction were due to the thalamic stroke. All the manifestations could be related to interruption of the frontal-subcortical circuitry.