The MRC National Survey of Health and Development reaches age 70: maintaining participation at older ages in a birth cohort study

Study Protocol - Insight 46 Cardiovascular: A Sub-study of the MRC National Survey of Health and Development

The commonest causes of dementia are Alzheimer's disease and vascular cognitive impairment. Although these conditions have been viewed as distinct entities, there is increasing evidence that neurodegenerative and vascular pathologies interact or overlap to cause cognitive decline, and that at least in some cases individuals at risk of cognitive decline exhibit abnormal cardiovascular physiology long before emergence of disease. However, the mechanisms linking haemodynamic disturbances with cognitive impairment and the various pathologies that cause dementia are poorly understood. A sub-sample of 502 participants from the Medical Research Council National Survey of Health and Development (NSHD) have participated in the first visit of a neuroscience sub-study referred to as Insight 46, where clinical, cognitive, imaging, and lifestyle data have been collected for the purpose of elucidating the pathological changes preceding dementia. This paper outlines the cardiovascular phenotyping performed in the follow-up visit of Insight 46, with the study participants now aged 74. In addition to standard cardiovascular assessments such as blood pressure measurements, echocardiography, and electrocardiography (ECG), functional Near Infrared Spectroscopy (fNIRS) has been included to provide an assessment of cerebrovascular function. A detailed description of the fNIRS protocol along with preliminary results from pilot data is presented. The combination of lifestyle data, brain structure/function, cognitive performance, and cardiovascular health obtained not only from Insight 46, but also from the whole NSHD provides an exciting opportunity to advance our understanding of the cardiovascular mechanisms underlying dementia and cognitive decline, and identify novel targets for intervention.

Increased variability in reaction time is associated with amyloid beta pathology at age 70

INTRODUCTION

We investigated whether life-course factors and neuroimaging biomarkers of Alzheimer's disease pathology predict reaction time (RT) performance in older adults.

METHODS

Insight 46 study participants, all born in the same week in 1946 (n = 501; ages at assessment = 69 to 71 years), completed a 2-choice RT task and amyloid beta (Aβ) positron emission tomography and MR imaging. We tested for associations between task outcomes (RT; error rate; intra-individual variability in RT) and life-course predictors including childhood cognitive ability and education. In a subsample of 406 cognitively normal participants, we investigated associations between task outcomes and biomarkers including Aβ-positivity.

RESULTS

Cognitively normal Aβ-positive participants had 10% more variable RTs than Aβ-negative participants, despite having similar mean RTs. Childhood cognitive ability and education independently predicted task performance.

DISCUSSION

This study provides novel evidence that Aβ pathology is associated with poorer consistency of RT in cognitively normal older adults, at an age when dementia prevalence is still very low.

Association Between Lifetime Affective Symptoms and Premature Mortality

Importance

Associations between affective symptoms and mortality have been evaluated, but studies have not examined timing or cumulative exposure to affective symptoms over the life course.

Objectives

To examine how lifetime accumulation and timing of affective symptoms are associated with mortality and identify potential explanatory factors.

Design, Setting, and Participants

Data were obtained from the MRC National Survey of Health and Development (1946 British birth cohort), a socially stratified, population-based sample originally consisting of 5362 singleton births in England, Wales, and Scotland during March 1946. The cohort has been followed up 24 times, most recently in 2014-2015. Eligible participants included those flagged for mortality with affective symptom data available at a minimum of 3 time points (n = 3001). Data analysis was conducted from July 2016 to January 2019.

Exposures

Affective symptoms were assessed at ages 13 to 15 years (teacher-rated questionnaire), 36 years (Present State Examination clinical semistructured interview), 43 years (Psychiatric Symptom Frequency questionnaire), and 53 years (General Health Questionnaire-28). Case-level affective symptoms were determined by those scoring in the top 16th percentile (ie, suggestive of a clinical diagnosis).

Main Outcomes and Measures

Mortality data were obtained from the UK National Health Service Central Register from age 53 to 68 years.

Results

Of 3001 study members (1509 [50.3%] female, 1492 [49.7%] male), 235 individuals (7.8%) died over a 15-year follow-up. After adjustment for sex, those who experienced case-level affective symptoms 1, 2, and 3 to 4 times had 76%, 87%, and 134% higher rates of premature mortality, respectively, compared with those who never experienced case-level symptoms. Case-level symptoms in adolescence only (ages 13-15 years) were associated with a 94% increased rate of mortality, which was unexplained after full adjustment for covariates (hazard ratio, 1.73; 95% CI, 1.10-2.72). Associations between participants with case-level symptoms multiple (2-4) times and mortality were predominately explained by adult health indicators and behaviors. For example, associations for those with case-level symptoms 3 to 4 times were most strongly attenuated by number of health conditions (32.1%), anxiolytic use (28.4%), lung function (24.6%), physical activity (23.9%), smoking (24.6%), antidepressant use (20.1%), diet (16.4%), pulse rate (12.7%), and adult social class (11.2%).

Conclusions and Relevance

Lifetime accumulation of affective symptoms may be associated with an increased rate of mortality, with explanatory pathways dependent on the duration and timing of symptoms. Future research into causal pathways and potential points of intervention should consider affective symptom history.

Amyloid β influences the relationship between cortical thickness and vascular load

INTRODUCTION

Cortical thickness has been proposed as a biomarker of Alzheimer's disease (AD)- related neurodegeneration, but the nature of its relationship with amyloid beta (Aβ) deposition and white matter hyperintensity volume (WMHV) in cognitively normal adults is unclear.

METHODS

We investigated the influences of Aβ status (negative/positive) and WMHV on cortical thickness in 408 cognitively normal adults aged 69.2 to 71.9 years who underwent 18F-Florbetapir positron emission tomography (PET) and structural magnetic resonance imaging (MRI). Two previously defined Alzheimer's disease (AD) cortical signature regions and the major cortical lobes were selected as regions of interest (ROIs) for cortical thickness.

RESULTS

Higher WMHV, but not Aβ status, predicted lower cortical thickness across all participants, in all ROIs. Conversely, when Aβ-positive participants were considered alone, higher WMHV predicted higher cortical thickness in a temporal AD-signature region.

DISCUSSION

WMHV may differentially influence cortical thickness depending on the presence or absence of Aβ, potentially reflecting different pathological mechanisms.

Associations Between Factors Across Life and One-Legged Balance Performance in Mid and Later Life: Evidence From a British Birth Cohort Study

Introduction: Despite its associations with falls, disability, and mortality, balance is an under-recognized and frequently overlooked aspect of aging. Studies investigating associations between factors across life and balance are limited. Understanding the factors related to balance performance could help identify protective factors and appropriate interventions across the life course. This study aimed to: (i) identify socioeconomic, anthropometric, behavioral, health, and cognitive factors that are associated with one-legged balance performance; and (ii) explore how these associations change with age.

Methods: Data came from 3,111 members of the MRC National Survey of Health and Development, a British birth cohort study. Multilevel models examined how one-legged standing balance times (assessed at ages 53, 60–64, and 69) were associated with 15 factors across life: sex, maternal education (4 years), paternal occupation (4 years), own education (26 years), own occupation (53 years), and contemporaneous measures (53, 60–64, 69 years) of height, BMI, physical activity, smoking, diabetes, respiratory symptoms, cardiovascular events, knee pain, depression and verbal memory. Age and sex interactions with each variable were assessed.

Results: Men had 18.8% (95%CI: 13.6, 23.9) longer balance times than women at age 53, although this difference decreased with age (11.8% at age 60–64 and 7.6% at age 69). Disadvantaged socioeconomic position in childhood and adulthood, low educational attainment, less healthy behaviors, poor health status, lower cognition, higher body mass index (BMI), and shorter height were associated with poorer balance at all three ages. For example, at age 53, those from the lowest paternal occupational classes had 29.6% (22.2, 38.8) worse balance than those from the highest classes. Associations of balance with socioeconomic indicators, cognition and physical activity became smaller with age, while associations with knee pain and depression became larger. There were no sex differences in these associations. In a combined model, the majority of factors remained associated with balance.

Discussion: This study identified numerous risk factors across life that are associated with one-legged balance performance and highlighted diverse patterns of association with age, suggesting that there are opportunities to intervene in early, mid and later life. A multifactorial approach to intervention, at both societal and individual levels, may have more benefit than focusing on a single risk factor.

The identification of probable sarcopenia in early old age based on the SARC-F tool and clinical suspicion: findings from the 1946 British birth cohort

Aim

To describe the prevalence of probable sarcopenia in a sample of older adults and to investigate (1) the SARC-F tool and (2) clinical risk factors in the identification of probable sarcopenia.

Findings

The prevalence of probable sarcopenia at age 69 was 19%, and a SARC-F score of ≥ 1 had a reasonable balance of sensitivity (65%) and specificity (72%) for probable sarcopenia. Three clinical risk factors were independently associated with probable sarcopenia: polypharmacy, lower body osteoarthritis and physical inactivity.

Message

Those with any positive responses to the questions in the SARC-F tool, a history of polypharmacy, lower body osteoarthritis or physical inactivity should be prioritised for the assessment of muscle strength.

Electronic supplementary material

The online version of this article (10.1007/s41999-020-00310-5) contains supplementary material, which is available to authorized users.

Purpose

The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) consensus definition introduced the concept of probable sarcopenia as a basis on which to begin treatment. Our aims were to describe the prevalence of probable sarcopenia in older adults and to investigate the utility of (1) the SARC-F tool and (2) clinical risk factors for the identification of those likely to have probable sarcopenia.

Methods

We used data from the 1946 British birth cohort at age 69, with 1686 participants included in the analyses. We used the EWGSOP2 cut points for weak grip strength and slow chair rise time, with the presence of one or both indicating probable sarcopenia. We examined the sensitivity and specificity of the SARC-F tool for probable sarcopenia. We also examined associations between clinical risk factors and probable sarcopenia.

Results

The prevalence of probable sarcopenia was 19%. A SARC-F score of ≥ 4 had low sensitivity (15%) and high specificity (99%) for probable sarcopenia, whereas a score of ≥ 1 had higher sensitivity (65%) and reasonable specificity (72%). Three clinical risk factors were independently associated with probable sarcopenia: polypharmacy [OR 2.7 (95% CI 1.7, 4.2)], lower body osteoarthritis [OR 1.8 (95% CI 1.3, 2.6)] and physical inactivity [OR of 2.1 (95% CI 1.5, 2.8)].

Conclusion

We have shown that EWGSOP2 probable sarcopenia is common in community-dwelling adults in early old age. Those with any positive responses to the questions in the SARC-F tool, a history of polypharmacy, lower body osteoarthritis or physical inactivity should be prioritised for the assessment of muscle strength.

Electronic supplementary material

The online version of this article (10.1007/s41999-020-00310-5) contains supplementary material, which is available to authorized users.

Age at period cessation and trajectories of cardiovascular risk factors across mid and later life

Objective

To examine the association between age at period cessation and trajectories of anthropometry, blood pressure, lipids and glycated haemoglobin (HbA1c) from midlife to age 69 years.

Methods

We used data from the UK Medical Research Council National Survey of Health and Development to examine the association between age at period cessation and trajectories of systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI) and waist circumference (WC) from 36 to 69 years and trajectories of triglyceride, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and HbA1c from 53 to 69 years.

Results

We found no evidence that age at period cessation was associated with trajectories of log triglyceride, LDL-C and HDL-C from 53 to 69 years and trajectories of SBP or DBP from 36 to 69 years, regardless of whether period cessation occurred naturally or due to hysterectomy. While we found some evidence of associations of age at period cessation with log BMI, log WC and log HbA1c, patterns were not consistent and differences were small at age 69 years, with confidence intervals that spanned the null value.

Conclusion

How and when women experience period cessation is unlikely to adversely affect conventional cardiovascular risk factors across mid and later life. Women and clinicians concerned about the impact of type and timing of period cessation on conventional cardiovascular intermediates from midlife should be reassured that the impact over the long term is small.

Systemic Inflammation and Cardio-Renal Organ Damage Biomarkers in Middle Age Are Associated With Physical Capability Up to 9 Years Later

Supplemental Digital Content is available in the text.

Background:

Physical capability, a key component of healthy aging, is associated with cardiovascular and other risk factors across life. We investigated whether midlife biomarkers of heart and kidney damage capturing the cumulative impact of long-term adverse exposures were associated with the level and decline in physical capability over 9 years of follow-up, taking account of systemic inflammatory biomarkers and conventional cardiovascular risk factors.

Methods:

We used data on 1736 men and women from the oldest British birth cohort study with walking speed, chair rise speed, balance time, and grip strength assessed at ages 60 to 64 and 69 years. We tested associations between logged and standardized measures of cystatin C, NT-proBNP (N-terminal pro-B-type natriuretic peptide), interleukin (IL)-6, and E-selectin at age 60 to 64 years with performance at age 69 years, adjusting for sex, height, and body mass index; then for performance at age 60 to 64 years. These biomarkers were mutually adjusted, and additionally adjusted for cardiovascular risk factors (pulse pressure, total/high density lipoprotein cholesterol, glycosylated hemoglobin), diabetes mellitus, cardiovascular and kidney disease, smoking status, and lifetime socioeconomic position.

Results:

Cystatin C, NT-proBNP, and IL-6 (but not E-selectin) were inversely associated with all outcomes, adjusted for sex, height, and body mass index. For example, a 1-SD increase in logged NT-proBNP was associated with weaker grip (−0.63 kg, 95% CI, −0.99 to −0.28); the equivalent association for cystatin C was −0.60 kg (95% CI, −0.94 to −0.25) and for IL-6 was −0.76 kg (95% CI, −1.11 to −0.41). Most associations remained, albeit attenuated, after adjustment for previous performance and mutual adjustment of the biomarkers. NT-proBNP and IL-6 (but not cystatin C) were more strongly associated with the outcomes than many of the conventional risk factors after mutual adjustment.

Conclusions:

Higher levels of NT-proBNP may identify those in midlife at risk of accelerated physical decline. Before considering the use of NT-proBNP for risk stratification, further research should untangle whether these associations exist because the biomarker is an integrated measure of cumulative exposures to relevant stressors across life, or whether it is marking additional risk pathways. Randomized trials to reduce the rate of decline in physical capability or delay incident disability could benefit from including middle-aged adults and adding NT-proBNP and IL-6 as intermediate outcomes.

Longitudinal associations between diurnal cortisol variation and later-life cognitive impairment

OBJECTIVE

To determine whether hypothalamus-pituitary-adrenal axis (HPAA) dysfunction is prospectively associated with global cognitive impairment in later life.

METHODS

This cross-cohort study integrates 2 large longitudinal datasets, Whitehall II and the National Survey for Health and Development (NSHD), on data collected in the Whitehall II study between 2002-2004, 2007-2009, and 2012-2013; and for NSHD between 2006-2010 and in 2015. Serial salivary cortisol samples were collected multiple times within a 24-hour period at mean ages 61.2 and 65.9 years in Whitehall II and at age 60-64 years from NSHD participants. Cortisol profile is defined using cortisol awakening response and am:pm ratio. Cognitive function was measured using the Mini-Mental State Examination in Whitehall II and Addenbrooke's Cognitive Examination, third version, in NSHD, harmonized into a 30-point score. Models were adjusted for age, sex, diagnoses of hypertension and diabetes, body mass index (BMI), educational attainment, and interval between HPAA and cognitive assessments.

RESULTS

In fully adjusted models, increased am:pm cortisol ratio was prospectively associated with better later-life cognitive function years later (0.02 fewer errors per SD increase in am:pm cortisol ratio, p < 0.01) and verbal fluency (0.03 SD increase in verbal fluency per SD increase in am:pm ratio, p < 0.01). Increasing age, lower educational attainment, diagnosis of hypertension, diagnosis of diabetes, and increased BMI were associated with worse cognitive function and poorer verbal fluency. There were no associations between depression and later-life cognition or reverse associations between cognition and later-life cortisol profiles.

CONCLUSIONS

Loss of diurnal HPAA variation is evident in individuals subsequently experiencing more cognitive impairment. It may serve as an early preclinical marker of cognitive decline.

Childhood Cognition and Age-Related Change in Standing Balance Performance From Mid to Later Life: Findings From a British Birth Cohort

BACKGROUND

Cognitive processing plays a crucial role in the integration of sensory input and motor output that facilitates balance. However, whether balance ability in adulthood is influenced by cognitive pathways established in childhood is unclear, especially as no study has examined if these relationships change with age. We aimed to investigate associations between childhood cognition and age-related change in standing balance between mid and later life.

METHODS

Data on 2,380 participants from the MRC National Survey of Health and Development were included in analyses. Repeated measures multilevel models estimated the association between childhood cognition, assessed at age 15, and log-transformed balance time, assessed at ages 53, 60-64, and 69 using the one-legged stand with eyes closed. Adjustments were made for sex, death, attrition, anthropometric measures, health conditions, health behaviors, education, other indicators of socioeconomic position (SEP), and adult verbal memory.

RESULTS

In a sex-adjusted model, 1 standard deviation increase in childhood cognition was associated with a 13% (95% confidence interval: 10, 16; p < .001) increase in balance time at age 53, and this association got smaller with age (cognition × age interaction: p < .001). Adjustments for education, adult verbal memory, and SEP largely explained these associations.

CONCLUSIONS

Higher childhood cognition was associated with better balance performance in midlife, with diminishing associations with increasing age. The impact of adjustment for education, cognition and other indicators of SEP suggested a common pathway through which cognition is associated with balance across life. Further research is needed to understand underlying mechanisms, which may have important implications for falls risk and maintenance of physical capability.

Cognition at age 70: Life course predictors and associations with brain pathologies

OBJECTIVE

To investigate predictors of performance on a range of cognitive measures including the Preclinical Alzheimer Cognitive Composite (PACC) and test for associations between cognition and dementia biomarkers in Insight 46, a substudy of the Medical Research Council National Survey of Health and Development.

METHODS

A total of 502 individuals born in the same week in 1946 underwent cognitive assessment at age 69-71 years, including an adapted version of the PACC and a test of nonverbal reasoning. Performance was characterized with respect to sex, childhood cognitive ability, education, and socioeconomic position (SEP). In a subsample of 406 cognitively normal participants, associations were investigated between cognition and β-amyloid (Aβ) positivity (determined from Aβ-PET imaging), whole brain volumes, white matter hyperintensity volumes (WMHV), and APOE ε4.

RESULTS

Childhood cognitive ability was strongly associated with cognitive scores including the PACC more than 60 years later, and there were independent effects of education and SEP. Sex differences were observed on every PACC subtest. In cognitively normal participants, Aβ positivity and WMHV were independently associated with lower PACC scores, and Aβ positivity was associated with poorer nonverbal reasoning. Aβ positivity and WMHV were not associated with sex, childhood cognitive ability, education, or SEP. Normative data for 339 cognitively normal Aβ-negative participants are provided.

CONCLUSIONS

This study adds to emerging evidence that subtle cognitive differences associated with Aβ deposition are detectable in older adults, at an age when dementia prevalence is very low. The independent associations of childhood cognitive ability, education, and SEP with cognitive performance at age 70 have implications for interpretation of cognitive data in later life.

Effects of affective symptoms in adolescence and adulthood on trajectories of cognitive function from middle to late adulthood

BACKGROUND

Little is known about the link between affective symptoms and cognitive function across the life course. This study aims to investigate whether affective symptoms in adolescence and adulthood predict trajectories of cognitive function from middle to late-adulthood.

METHODS

Data from the MRC National Survey of Health and Development (NSHD), a cohort of 5362 individuals born in mainland UK in 1946, were utilised. Linear mixed models were used to model cognitive trajectories (memory and processing speed) over a three-decade period (from 43 to 69) and to test effects of affective symptoms in adolescence (ages 13-15) and adulthood (ages 36 and 43) on cognitive function at first testing (age 43) and decline in cognitive function (from 43 to 69). Models were adjusted for sex, childhood cognition, childhood socioeconomic position, and education.

RESULTS

A quadratic model best fitted memory and processing speed data. Models revealed that adolescent affective symptoms were associated with lower memory (b = -1.11, SE = 0.53, p = .04) and processing speed (b = -18.17, SE = 7.53, p = .02) at first cognitive testing, but not with rates of decline from 43 to 69. There were no significant associations between adult affective symptoms and cognitive trajectories.

LIMITATIONS

Missing data is a potential limitation of this study. This was dealt with using maximum likelihood estimation and multiple imputation.

CONCLUSIONS

Findings suggest that adolescent, but not adult, affective symptoms are important predictors of cognitive function in midlife, but not rate of cognitive decline. This highlights the importance of early intervention to manage mental health in adolescence to protect later cognitive function.

C9orf72 and intracerebral hemorrhage

The chromosome 9 open reading frame 72 (C9orf72) GGGGCC repeat expansion has been associated with several diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. It has also been associated with increased white matter changes in frontotemporal dementia and risk of cognitive impairment in ALS. Dementia is common both before and after intracerebral hemorrhage (ICH). Because the mechanisms of cognitive impairment in patients with ICH are uncertain, we investigated whether C9orf72 could influence dementia risk in this patient group. Therefore, we genotyped 1010 clinically characterized ICH cases and 2147 population controls in comparison with prior data of dementia and ALS cases. We did not find any association between C9orf72 repeat expansion and repeat size with ICH compared with controls or with dementia when assessing ICH patients only. The frequency of C9orf72 expansions in our series of individuals born in 1946 (2/2147) and other U.K. controls was age dependent, decreasing with increasing age, highlighting the high age-dependent penetrance of this expansion.

Variations of health check attendance in later life: results from a British birth cohort study

BACKGROUND

Older adults are advised to attend a number of preventive health checks to preserve health and identify risk factors for disease. Previous research has identified a number of health and social factors, labelled as predisposing, enabling and need factors, using Andersen's Behavioural Model of Health Service Use, that are associated with health care utilisation. We aimed to assess associations between factors from childhood and adulthood, and health check attendance in later life in a British birth cohort study.

METHODS

For 2370 study members from the MRC National Survey of Health and Development (NSHD), health check attendance was assessed at age 68. Study members were asked if they: attended blood pressure and cholesterol checks, had their eyes tested, received the influenza vaccine, attended colon cancer screening and dental checks. Health and social factors from childhood and adulthood were used in binomial regression models to test associations with health check attendance in men and women.

RESULTS

Health check attendance was high; 41% reported attending all six health checks within the recommended time frame. In multivariable models, being a non-smoker and having more health conditions in adulthood were associated with greater health check attendance in men and women. In women, childhood socioeconomic advantage, being more physically active in midlife and previously attending screening procedures, and in men, greater self-organisation in adolescence and being married were associated with attending more health checks in later life, following adjustments for childhood and adulthood factors.

CONCLUSIONS

A number of predisposing, enabling and need factors from childhood and adulthood were found to be associated with health check attendance at age 68, demonstrating the relevance of applying a life course perspective to Andersen's model in investigating health check attendance in later life. Health related factors were found to be stronger correlates of health check attendance than socioeconomic factors.

Correlates of high-impact physical activity measured objectively in older British adults

Background

Exposure to higher magnitude vertical impacts is thought to benefit bone health. The correlates of this high-impact physical activity (PA) in later life are unknown.

Methods

Participants were from the Cohort for Skeletal Health in Bristol and Avon, Hertfordshire Cohort Study and MRC National Survey of Health and Development. Associations of demographic, behavioural, physiological and psychological factors with vertical acceleration peaks ≥1.5 g (i.e. high-impact PA) from 7-day hip-worn accelerometer recordings were examined using linear regression.

Results

A total of 1187 participants (mean age = 72.7 years, 66.6% females) were included. Age, sex, education, active transport, self-reported higher impact PA, walking speed and self-rated health were independently associated with high-impact PA whereas BMI and sleep quality showed borderline independent associations. For example, differences in log-high-impact counts were 0.50 (P < 0.001) for men versus women and −0.56 (P < 0.001) for worst versus best self-rated health. Our final model explained 23% of between-participant variance in high impacts. Other correlates were not associated with high-impact activity after adjustment.

Conclusions

Besides age and sex, several factors were associated with higher impact PA in later life. Our findings help identify characteristics of older people that might benefit from interventions designed to promote osteogenic PA.

Hippocampal subfield volumes and pre-clinical Alzheimer's disease in 408 cognitively normal adults born in 1946

BACKGROUND

The human hippocampus comprises a number of interconnected histologically and functionally distinct subfields, which may be differentially influenced by cerebral pathology. Automated techniques are now available that estimate hippocampal subfield volumes using in vivo structural MRI data. To date, research investigating the influence of cerebral β-amyloid deposition-one of the earliest hypothesised changes in the pathophysiological continuum of Alzheimer's disease-on hippocampal subfield volumes in cognitively normal older individuals, has been limited.

METHODS

Using cross-sectional data from 408 cognitively normal individuals born in mainland Britain (age range at time of assessment = 69.2-71.9 years) who underwent cognitive assessment, 18F-Florbetapir PET and structural MRI on the same 3 Tesla PET/MR unit (spatial resolution 1.1 x 1.1 x 1.1. mm), we investigated the influences of β-amyloid status, age at scan, and global white matter hyperintensity volume on: CA1, CA2/3, CA4, dentate gyrus, presubiculum and subiculum volumes, adjusting for sex and total intracranial volume.

RESULTS

Compared to β-amyloid negative participants (n = 334), β-amyloid positive participants (n = 74) had lower volume of the presubiculum (3.4% smaller, p = 0.012). Despite an age range at scanning of just 2.7 years, older age at time of scanning was associated with lower CA1 (p = 0.007), CA4 (p = 0.004), dentate gyrus (p = 0.002), and subiculum (p = 0.035) volumes. There was no evidence that white matter hyperintensity volume was associated with any subfield volumes.

CONCLUSION

These data provide evidence of differential associations in cognitively normal older adults between hippocampal subfield volumes and β-amyloid deposition and, increasing age at time of scan. The relatively selective effect of lower presubiculum volume in the β-amyloid positive group potentially suggest that the presubiculum may be an area of early and relatively specific volume loss in the pathophysiological continuum of Alzheimer's disease. Future work using higher resolution imaging will be key to exploring these findings further.

The effect of mid-life insulin resistance and type 2 diabetes on older-age cognitive state: the explanatory role of early-life advantage

AIMS/HYPOTHESIS

Type 2 diabetes, hyperglycaemia and insulin resistance are associated with cognitive impairment and dementia, but causal inference studies using Mendelian randomisation do not confirm this. We hypothesised that early-life cognition and social/educational advantage may confound the relationship.

METHODS

From the population-based British 1946 birth cohort, a maximum number of 1780 participants had metabolic variables (type 2 diabetes, insulin resistance [HOMA2-IR] and HbA1c) assessed at age 60-64 years, and cognitive state (Addenbrooke's Cognitive Examination III [ACE-III]) and verbal memory assessed at age 69 years. Earlier-life measures included socioeconomic position (SEP), cognition at age 8 years and educational attainment. Polygenic risk scores (PRSs) for type 2 diabetes were calculated. We first used a PRS approach with multivariable linear regression to estimate associations between PRSs and metabolic traits and later-life cognitive state. Second, using a path model approach, we estimated the interrelationships between earlier-life measures, features of mid-life type 2 diabetes and cognitive state at age 69 years. All models were adjusted for sex.

RESULTS

The externally weighted PRS for type 2 diabetes was associated with mid-life metabolic traits (e.g. HOMA2-IR β = 0.08 [95% CI 0.02, 0.16]), but not with ACE-III (β = 0.04 [-0.02, 0.90]) or other cognitive outcomes. While there was an association between HOMA2-IR and subsequent ACE-III (β = -0.09 [-0.15, -0.03]), path modelling showed no direct effect (β = -0.01 [-0.06, 0.03]) after accounting for the association between childhood SEP and education with HOMA2-IR. The same pattern was observed for later-life verbal memory.

CONCLUSIONS/INTERPRETATION

Associations between type 2 diabetes and mid-life metabolic traits with subsequent cognitive state do not appear causal, and instead they may be explained by SEP in early life, childhood cognition and educational attainment. Therefore, glucose-lowering medication may be unlikely to combat cognitive impairment in older age.

Early-life adversity, later-life mental health, and resilience resources: a longitudinal population-based birth cohort analysis

BACKGROUND

Robust and persistent links between early-life adversities and later-life mental distress have previously been observed. Individual and social resources are associated with greater mental health and resilience. This study aimed to test these resources as moderators and mediators of the association between childhood psychosocial adversity and later-life mental distress.

METHODS

Participant data came from the Medical Research Council National Survey of Health and Development, a nationally-representative birth cohort study. The General Health Questionnaire-28 (GHQ-28) captured mental distress at ages 53, 60-64, and 68-69. An eight-item cumulative psychosocial adversity score was created (0, 1, 2, ≥3 adversities). Individual (i.e., education, occupational status, physical activity) and social (i.e., social support, neighborhood cohesion) resources were examined as mediators and moderators of CPA and GHQ-28 in longitudinal multilevel models.

FINDINGS

Greater adversity was associated with an average GHQ-28 score increase of 0.017, per unit adversity (β = 0·017, p < 0·001, 95% CI 0·011, 0·022). Lower mental distress was associated with higher levels of physical activity, occupational status, education, social support, and neighborhood cohesion. There was no evidence that resources moderated the relationship between GHQ-28 and adversity. All resources, save for physical activity and occupational status, partly mediated this relationship.

CONCLUSIONS

Individual and social resources were associated with lower mental distress. They did not modify, but partly mediated the association between childhood adversity and adult mental distress. Social support was the most important mediator, suggesting that interventions to promote greater social support may offset psychosocial adversities experienced in childhood to foster better mental health in older adults.

Systemic inflammation and modifiable risk factors for cognitive impairment in older persons: Findings from a British birth cohort

Serum pro‐inflammatory markers may contribute to dementia pathophysiology and cognitive impairment. In a population‐representative birth cohort, serum C‐reactive protein (CRP), interleukin‐6 (IL‐6), and white cell count (WCC) were measured at age 60‐64 years and cognition was assessed using the Addenbrooke's Cognitive Examination (ACE‐III) at age 69 years. Higher baseline CRP and IL‐6 were associated with lower ACE‐III scores, but associations were attenuated on adjustment for educational attainment, sex, and other modifiable life course factors. No associations were found for CRP, IL‐6, and WCC with visual search speed or verbal memory. In conclusion, the relationship between increased baseline systemic inflammation and poorer cognition in later life may be explained by, or share pathways with, education and other modifiable life course factors.

Day-to-day physical activity producing low gravitational impacts is associated with faster visual processing speed at age 69: cross-sectional study

BACKGROUND

Little is known about how different physical activity (PA) parameters relate to cognitive function in older adults. Using accelerometers calibrated to detect vertical impacts from ground reaction forces we examined the associations of low, medium and higher impact PA with processing speed, verbal memory and cognitive state in older adults.

METHODS

Participants were 69-year old British men and women from the Medical Research Council National Survey of Health and Development included in a vertical impacts and bone sub-study (n = 558; 48.2% female). Counts of low (0.5 < g < 1.0 g), medium (1 < g < 1.5 g), or higher (≥1.5 g) magnitude impacts were derived from vertical acceleration peaks recorded over 7 days by hip-worn accelerometers. Processing speed was assessed by a timed visual letter search task, verbal memory by a 15-word list learning test and cognitive state by the Addenbrooke's Cognitive Examination (ACE-III). Potential confounders were childhood cognitive ability, adult socioeconomic position, body mass index and depression.

RESULTS

In initial sex-adjusted models, low magnitude impacts were associated with better performance in all three cognitive function tests; standard deviation differences in test scores per doubling in number of low impacts: letter search speed = 0.10 (95% confidence intervals (CI): 0.03 to 0.16), word learning test = 0.05 (95% CI: 0.00 to 0.11), ACE-III scale = 0.09 (95% CI: 0.03 to 0.14). After adjustment for confounders, differences persisted for letter search speed (0.09; 95% CI: 0.02 to 0.16) but were closer to the null for the word learning test (0.02; 95% CI: - 0.04 to 0.07) and ACE-III scores (0.04; 95% CI: - 0.01 to 0.09). Low impacts remained associated with letter search speed after sensitivity analyses excluding those with functional and musculoskeletal problems, and after adjustment for impacts in higher bands. Modest positive associations between higher magnitude impacts and cognitive test scores were most likely due to chance.

CONCLUSION

Accelerometer-derived low impact physical activity was associated with better visual processing speed in 69-year old men and women independently of childhood cognitive ability and other measured confounders. Day-to-day low impact physical activity may therefore have the potential to benefit cognitive health in older adults.

Obesity and Polypharmacy among African American Older Adults: Gender as the Moderator and Multimorbidity as the Mediator

Despite high prevalence of obesity and polypharmacy among African American (AA) older adults, little information exists on the associations between the two in this population. This study explored the association between obesity and polypharmacy among AA older adults who were residing in poor urban areas of South Los Angeles. We also investigated role of gender as the moderator and multimorbidity as the mediator of this association. In a community-based study in South Los Angeles, 308 AA older adults (age ≥ 55 years) were entered into this study. From this number, 112 (36.4%) were AA men and 196 (63.6%) were AA women. Polypharmacy (taking 5+ medications) was the dependent variable, obesity was the independent variable, gender was the moderator, and multimorbidity (number of chronic medical conditions) was the mediator. Age, educational attainment, financial difficulty (difficulty paying bills, etc.), income, marital status, self-rated health (SRH), and depression were the covariates. Logistic regressions were used for data analyses. In the absence of multimorbidity in the model, obesity was associated with higher odds of polypharmacy in the pooled sample. This association was not significant when we controlled for multimorbidity, suggesting that multimorbidity mediates the obesity-polypharmacy link. We found significant association between obesity and polypharmacy in AA women not AA men, suggesting that gender moderates such association. AA older women with obesity are at a higher risk of polypharmacy, an association which is mainly due to multimorbidity. There is a need for screening for inappropriate polypharmacy in AA older women with obesity and associated multimorbidity.

Developmental factors associated with decline in grip strength from midlife to old age: a British birth cohort study

OBJECTIVES

To test whether developmental factors are associated with grip strength trajectories between 53 and 69 years, and operate independently or on the same pathway/s as adult factors.

DESIGN

British birth cohort study.

SETTING

England, Scotland and Wales.

PARTICIPANTS

3058 men and women.

MAIN OUTCOME MEASURES

Grip strength (kg) at ages 53, 60-64 and 69 were analysed using multilevel models to estimate associations with developmental factors (birth weight, growth parameters, motor and cognitive development) and father's social class, and investigate adult factors that could explain observed associations, testing for age and sex interactions.

RESULTS

In men, heavier birth weight, beginning to walk 'on time', later puberty and greater weight 0-26 years and in women, heavier birth weight and earlier age at first standing were independently associated with stronger grip but not with its decline. The slower decline in grip strength (by 0.07 kg/year, 95% CI 0.02 to 0.11 per 1 SD, p=0.003) in men of higher cognitive ability was attenuated by adjusting for adult verbal memory.

CONCLUSIONS

Patterns of growth and motor development have persisting associations with grip strength between midlife and old age. The strengthening associations with cognition suggest that, at older ages, grip strength increasingly reflects neural ageing processes. Interventions across life that promote muscle development or maintain muscle strength should increase the chance of an independent old age.

Associations between Polypharmacy, Self-Rated Health, and Depression in African American Older Adults; Mediators and Moderators

Background. Despite the prevalence of multimorbidity among African American (AA) older adults, little information exists on correlates of polypharmacy (using 5+ medications) in AA older adults. There is more information available regarding the link between polypharmacy and physical aspects of health than subjective ones. Aims. In a local sample of AA older adults in Los Angeles, this study investigated the association of polypharmacy with self-rated health (SRH) and depression. We also explored gender differences in these links. Methods. This community-based study was conducted in south Los Angeles. A total number of 708 AA older adults (age ≥ 55 years) were entered into this study. From this number, 253 were AA men and 455 were AA women. Polypharmacy was the independent variable. Self-rated health (SRH) and depression were the dependent variables. Age, educational attainment, financial difficulty (difficulty paying bills, etc.), and marital status were covariates. Gender was the moderator. Multimorbidity, measured as the number of chronic diseases (CDs), was the mediator. Logistic regressions were applied for data analysis. Results. Polypharmacy was associated with worse SRH and depression. Multimorbidity fully mediated the association between polypharmacy and depressive symptoms. Multimorbidity only partially mediated the association between polypharmacy and poor SRH. Gender moderated the association between polypharmacy and SRH, as polypharmacy was associated with poor SRH in women but not men. Gender did not alter the association between polypharmacy and depression. Conclusions. AA older women with polypharmacy experience worse SRH and depression, an association which is partially due to the underlying multimorbidity. There is a need for preventing inappropriate polypharmacy in AA older adults, particularly when addressing poor SRH and depression in AA older women with multimorbidity.

Race/Ethnicity, Socioeconomic Status, and Polypharmacy among Older Americans

Background: Very few studies with nationally representative samples have investigated the combined effects of race/ethnicity and socioeconomic position (SEP) on polypharmacy (PP) among older Americans. For instance, we do not know if prevalence of PP differs between African Americans (AA) and white older adults, whether this difference is due to a racial gap in SEP, or whether racial and ethnic differences exist in the effects of SEP indicators on PP. Aims: We investigated joint effects of race/ethnicity and SEP on PP in a national household sample of American older adults. Methods: The first wave of the University of Michigan National Poll on Healthy Aging included a total of 906 older adults who were 65 years or older (80 AA and 826 white). Race/ethnicity, SEP (income, education attainment, marital status, and employment), age, gender, and PP (using 5+ medications) were measured. Logistic regression was applied for data analysis. Results: Race/ethnicity, age, marital status, and employment did not correlate with PP; however, female gender, low education attainment, and low income were associated with higher odds of PP among participants. Race/ethnicity interacted with low income on odds of PP, suggesting that low income might be more strongly associated with PP in AA than white older adults. Conclusions: While SEP indicators influence the risk of PP, such effects may not be identical across diverse racial and ethnic groups. That is, race/ethnicity and SEP have combined/interdependent rather than separate/independent effects on PP. Low-income AA older adults particularly need to be evaluated for PP. Given that race and SEP have intertwined effects on PP, racially and ethnically tailored interventions that address PP among low-income AA older adults may be superior to universal interventions and programs that ignore the specific needs of diverse populations. The results are preliminary and require replication in larger sample sizes, with PP measured directly without relying on individuals’ self-reports, and with joint data collected on chronic disease.

Identifying the lifetime cognitive and socioeconomic antecedents of cognitive state: seven decades of follow-up in a British birth cohort study

OBJECTIVES

The life course determinants of midlife and later life cognitive function have been studied using longitudinal population-based cohort data, but far less is known about whether the pattern of these pathways is similar or distinct for clinically relevant cognitive state. We investigated this for Addenbrooke's Cognitive Examination third edition (ACE-III), used in clinical settings to screen for cognitive impairment and dementia.

DESIGN

Longitudinal birth cohort study.

SETTING

Residential addresses in England, Wales and Scotland.

PARTICIPANTS

1762 community-dwelling men and women of European heritage, enrolled since birth in the Medical Research Council (MRC) National Survey of Health and Development (the British 1946 birth cohort).

PRIMARY OUTCOME

ACE-III.

RESULTS

Path modelling estimated direct and indirect associations between apolipoprotein E (APOE) status, father's social class, childhood cognition, education, midlife occupational complexity, midlife verbal ability (National Adult Reading Test; NART), and the total ACE-III score. Controlling for sex, there was a direct negative association between APOE ε4 and the ACE-III score (β=-0.04 [-0.08 to -0.002], p=0.04), but not between APOE ε4 and childhood cognition (β=0.03 [-0.006 to 0.069], p=0.10) or the NART (β=0.0005 [-0.03 to 0.03], p=0.97). The strongest influences on the ACE-III were from childhood cognition (β=0.20 [0.14 to 0.26], p<0.001) and the NART (β=0.35 [0.29 to 0.41], p<0.001); educational attainment and occupational complexity were modestly and independently associated with the ACE-III (β=0.08 [0.03 to 0.14], p=0.002 and β=0.05 [0.01 to 0.10], p=0.02, respectively).

CONCLUSIONS

The ACE-III in the general population shows a pattern of life course antecedents that is similar to neuropsychological measures of cognitive function, and may be used to represent normal cognitive ageing as well as a screen for cognitive impairment and dementia.

Longitudinal profiles of back pain across adulthood and their relationship with childhood factors: evidence from the 1946 British birth cohort

Supplemental Digital Content is Available in the Text.

In a British birth cohort study, 4 distinct long-term back pain profiles were identified, each of which was associated with different early life risk factors.

This study aimed to (1) characterise long-term profiles of back pain across adulthood and (2) examine whether childhood risk factors were associated with these profiles, using data from 3271 participants in the Medical Research Council National Survey of Health and Development. A longitudinal latent class analysis was conducted on binary outcomes of back pain at ages 31, 36, 43, 53, 60 to 64, and 68 years. Multinomial logistic regression models were used to examine associations between selected childhood risk factors and class membership; adjusted for sex, adult body size, health status and behaviours, socioeconomic position, and family history of back pain. Four profiles of back pain were identified: no or occasional pain (57.7%), early-adulthood only (16.1%), mid-adulthood onset (16.9%), and persistent (9.4%). The “no or occasional” profile was treated as the referent category in subsequent analyses. After adjustment, taller height at age 7 years was associated with a higher likelihood of early-adulthood only (relative risk ratio per 1 SD increase in height = 1.31 [95% confidence interval: 1.05-1.65]) and persistent pain (relative risk ratio = 1.33 [95% confidence interval: 1.01-1.74]) in women (P for sex interaction = 0.01). Factors associated with an increased risk of persistent pain in both sexes were abdominal pain, poorest care in childhood, and poorer maternal health. Abdominal pain and poorest housing quality were also associated with an increased likelihood of mid-adulthood onset pain. These findings suggest that there are different long-term profiles of back pain, each of which is associated with different early life risk factors. This highlights the potential importance of early life interventions for the prevention and management of back pain.

Associations of medical conditions, lifestyle and unintentional weight loss in early old age: The 1946 British Birth Cohort

Background

Unintentional weight loss in older people has been linked to increased risk of mortality. We aimed to investigate common medical conditions and lifestyle factors, including body fat distribution, as potential determinants of recent and prospective unintentional weight loss in early old age.

Methods

From the Medical Research Council (MRC) National Survey of Health and Development (NSHD), we included a total of 2234 study members aged 60–64 with information on unintentional weight loss in 2006–2010. Of these, 2136 also had information on unintentional weight loss recorded in 2015. Logistic regression was conducted to examine the associations between medical conditions, lifestyle, and body fat distribution at age 60–64 and unintentional weight loss at age 60–64 and 69.

Results

A total of 109 of 2234 study members had unintentional weight loss at ages 60–64, and 166 of 2136 at age 69. Never smoking was associated with lower risk of unintentional weight loss at age 60–64 (OR = 0.29, 95%CI = 0.12–0.68 compared to current smokers), and this association remained when adjusted for other determinants. Greater waist-hip ratio (OR = 0.95, 95%CI = 0.91–0.99) and body fat-lean mass ratio (OR = 0.96, 95%CI = 0.94–0.99) were associated with less likelihood of unintentional weight loss at age 60–64. Never smoking and greater hip circumference at age 60–64 were associated with lower odds of unintentional weight loss at age 69.

Conclusions

Smoking status and body fat distribution may help identify those at risk of unintentional weight loss in early old age. Their benefit in interventions to prevent age-associated weight loss needs to be further investigated.

Polypharmacy in African American Adults: A National Epidemiological Study

Background: Despite the association between polypharmacy and undesired health outcomes being well established, very little is known about epidemiology of polypharmacy in the African American community. We are not aware of any nationally representative studies that have described the socioeconomic, behavioral, and health determinants of polypharmacy among African Americans. Aims: We aimed to investigate the socioeconomic and health correlates of polypharmacy in a national sample of African American adults in the US. Methods: The National Survey of American Life (NSAL, 2003⁻2004) included 3,570 African American adults. Gender, age, socioeconomic status (SES; education attainment, poverty index, and marital status), access to the healthcare system (health insurance and having a usual source of care), and health (self-rated health [SRH], chronic medical disease, and psychiatric disorders) in addition to polypharmacy (5 + medications) as well as hyper-polypharmacy (10 + medications) were measured. Logistic regressions were applied for statistical analysis. Results: that About 9% and 1% of all African American adults had polypharmacy and hyper-polypharmacy, respectively. Overall, higher age, higher SES (education and poverty index), and worse health (poor SRH, more chronic medical disease, and psychiatric disorders) were associated with polypharmacy and hyper-polypharmacy. Individuals with insurance and those with a routine place for healthcare also had higher odds of polypharmacy and hyper-polypharmacy. Conclusions: Given the health risks associated with polypharmacy, there is a need for systemic evaluation of medication use in older African Americans with multiple chronic conditions. Such policies may prevent medication errors and harmful drug interactions, however, they require effective strategies that are tailored to African Americans.

Social relationship adversities throughout the lifecourse and risk of loneliness in later life

Understanding how social experiences throughout life shape later loneliness levels may help to identify how to alleviate loneliness at later lifestages. This study investigates the association between social relationship adversities throughout the lifecourse and loneliness in later life. Using prospective data from the Medical Research Council National Survey of Health and Development (N = 2,453), we conducted multivariable analyses to investigate independent, cumulative and moderated effects between the number of social relationship adversities experienced in childhood, mid-adulthood and later adulthood and the feeling of loneliness at age 68. We examined interactions between social relationship adversities and current quantity and quality aspects of social relationships. We found evidence of a step-dose response where greater exposure to social relationship adversities experienced at three earlier lifestages predicted higher loneliness levels in later life with more recent social relationship adversities more strongly related to loneliness. The results also demonstrated support for exacerbation and amelioration of earlier adverse social relationship experiences by current social isolation and relationship quality, respectively. This study suggests that social relationship adversities experienced throughout the lifecourse continue to influence loneliness levels much later in life. A key finding is that adverse social relationship experiences in earlier life may explain why otherwise socially similar individuals differ in their levels of loneliness. Implications for policy and research are discussed.

Factors across life associated with remaining free from functional limitations despite lifelong exposure to socioeconomic adversity

BACKGROUND

There are substantial socioeconomic inequalities in functional limitations in old age. Resilience may offer new insights into these inequalities by identifying constellations of factors that protect some individuals from developing functional limitations despite socioeconomic adversity.

METHODS

Data from 1973 participants in the Medical Research Council National Survey of Health and Development (Great Britain), followed from birth until age 60-64, were used. Functional limitations were defined as reporting difficulty with at least 1 of 16 activities at age 60-64. Lifetime socioeconomic adversity was based on socioeconomic trajectories, categorised into three adversity levels. Analysis of covariance and regression models were used to compare psychosocial factors and health-related behaviours between a 'Resilient' group (high adversity but no functional limitations) and five groups with other combinations of adversity and limitations.

RESULTS

Prevalence of functional limitations in high, intermediate and low adversity groups was 44%, 30% and 23% in men, and 61%, 55% and 49% in women, respectively. Compared with the other high adversity group, the resilient group had a lower prevalence of childhood illness (12% vs 19%) and obesity throughout ages 43-64 (70% vs 55%). Partially adjusted models also showed higher adolescent self-management, lower neuroticism, higher prevalence of volunteer work and physical activity (age 60-64) and lower prevalence of smoking (age 43) in the resilient. Marital status and contact frequency were not associated with resilience.

CONCLUSION

Results suggest protection against childhood illness, health-behavioural factors and self-regulation as targets for interventions across life that may particularly benefit those with long-term exposure to socioeconomic adversity.

Metabolomic correlates of central adiposity and earlier-life body mass index

BMI is correlated with circulating metabolites, but few studies discuss other adiposity measures, and little is known about metabolomic correlates of BMI from early life. We investigated associations between different adiposity measures, BMI from childhood through adulthood, and metabolites quantified from serum using ¹H NMR spectroscopy in 900 British men and women aged 60-64. We assessed BMI, waist-to-hip ratio (WHR), android-to-gynoid fat ratio (AGR), and BMI from childhood through adulthood. Linear regression with Bonferroni adjustment was performed to assess adiposity and metabolites. Of 233 metabolites, 168; 126; and 133 were associated with BMI, WHR, and AGR at age 60-64, respectively. Associations were strongest for HDL, particularly HDL particle size-e.g., there was 0.08 SD decrease in HDL diameter (95% CI: 0.07-0.10) with each unit increase in BMI. BMI-adjusted AGR or WHR were associated with 31 metabolites where there was no metabolome-wide association with BMI. We identified inverse associations between BMI at age 7 and glucose or glycoprotein at age 60-64 and relatively large LDL cholesteryl ester with postadolescent BMI gains. In summary, we identified metabolomic correlates of central adiposity and earlier-life BMI. These findings support opportunities to leverage metabolomics in early prevention of cardiovascular risk attributable to body fatness.

Linking local labour market conditions across the life course to retirement age: Pathways of health, employment status, occupational class and educational achievement, using 60 years of the 1946 British Birth Cohort

Several studies have documented that older workers who live in areas with higher unemployment rates are more likely to leave work for health and non-health reasons. Due to tracking of area disadvantage over the life course, and because negative individual health and socioeconomic factors are more likely to develop in individuals from disadvantaged areas, we do not know at what specific ages, and through which specific pathways, area unemployment may be influencing retirement age. Using data from the MRC National Survey of Health and Development, we use structural equation modelling to investigate pathways linking local authority unemployment at three ages (4y, 26y and 53y) to age of retirement (right-censored). We explored five hypothesized pathways: (1) residential tracking, (2) health, (3) employment status, (4) occupational class, and (5) education. Initially, pathways between life course area unemployment, each pathway and retirement age were assessed individually. Mediation pathways were tested in the full model. Our results showed that area unemployment tracked across the life course. Higher area unemployment at ages 4 and 53 were independently associated with earlier retirement age [1% increase = mean -0.64 (95% CI: -1.12, -0.16) and -0.25 (95% CI: -0.43, -0.06) years]. Both were explained by adjustment for individual employment status at ages 26 and 53 years. Higher area unemployment at age 26 was associated with poorer health and lower likelihood of employment at aged 53; and these 2 individual pathways were identified as the key mediators between area unemployment and retirement age. In conclusion, these results suggest that interventions designed to create local employment opportunities for young adults should lead to extended working through improved employment and health at mid-life.

Lifetime socioeconomic circumstances and chronic pain in later adulthood: findings from a British birth cohort study

OBJECTIVES

To investigate associations between a range of different indicators of socioeconomic position (SEP: occupational class, education, household overcrowding and tenure, and experience of financial hardship) across life and chronic widespread and regional pain (CWP and CRP) at age 68.

DESIGN

Prospective birth cohort; the Medical Research Council National Survey of Health and Development.

SETTING

England, Scotland and Wales.

PARTICIPANTS

Up to 2378 men and women who have been followed-up since birth in 1946 to age 68.

PRIMARY OUTCOME MEASURES

On the basis of their self-report of pain at age 68, participants were classified as: CWP (American College of Rheumatology criteria), CRP (pain of at least 3 months' duration but that does not meet the definition of CWP), other pain (<3 months in duration) or no pain.

RESULTS

At age 68, the prevalence of CWP was 13.3% and 7.8% in women and men, respectively, and that of CRP was 32.3% and 28.7% in women and men, respectively. There was no clear evidence that indicators of SEP in childhood or later adulthood were associated with pain. Having experienced (vs not) financial hardship and being a tenant (vs owner-occupier) in earlier adulthood were both associated with an increased risk of CWP; for example, moderate hardship adjusted relative risk ratio (RRR_adj) 2.32 (95% CI: 1.19 to 4.52) and most hardship RRR_adj 4.44 (95% CI: 2.02 to 9.77). Accumulation of financial hardship across earlier and later adulthood was also associated with an increased risk of CWP.

CONCLUSIONS

Consideration of socioeconomic factors in earlier adulthood may be important when identifying targets for intervention to prevent CWP in later life.

Adherence to a Dietary Approaches to Stop Hypertension (DASH)-type diet over the life course and associated vascular function: a study based on the MRC 1946 British birth cohort

Little is known about long-term associations between the Dietary Approaches to Stop Hypertension (DASH) diet and conventional cardiovascular (CV)-risk factors as well as novel measures of vascular function. This study aimed to examine whether long-term adherence to a DASH-type diet in a British birth cohort is associated with conventional CV-risk factors and two vascular function markers, carotid intima-media thickness (cIMT) and pulse wave velocity (PWV). Data came from 1409 participants of the Medical Research Council (MRC) National Survey of Health and Development. Dietary intake was assessed at 36, 43, 53 and 60-64 years using 5-d estimated food diaries. The DASH-type diet score was calculated using the Fung index. Conventional CV-risk factors (blood pressure (BP) and lipids), cIMT in the right and/or left common carotid artery and PWV was measured when participants were 60-64 years. Associations between the DASH-type diet score and outcomes were assessed using multiple regression models adjusted for socioeconomic position, BMI, smoking and physical activity. Participants in higher sex-specific quintiles (Q) of the long-term DASH-type diet had lower BP (P≤0·08), higher HDL-cholesterol (P<0·001) and lower TAG (P<0·001) compared with people in Q1. Participants in Q5 of the long-term DASH-type diet had lower PWV (-0·28 sd; 95 % CI -0·50, -0·07, P trend=0·01) and cIMT (-0·24 sd; 95 % CI -0·44, -0·04, P trend=0·02) compared with participants in the Q1. This association was independent of the conventional CV-risk factors. Greater adherence to a DASH diet over the life course is associated with conventional CV-risk factors and independently associated with cIMT and PWV.

Polypharmacy and Psychological Distress May Be Associated in African American Adults

Background: Compared to Whites, African Americans are at a higher risk of multiple chronic conditions, which places them at a higher risk of polypharmacy. Few national studies, however, have tested whether polypharmacy is associated with psychological distress—the net of socioeconomic status, health status, and stress—in African Americans. Aims: In a national sample of African Americans in the US, this study investigated the association between polypharmacy and psychological distress. Methods: The National Survey of American Life (NSAL, 2003) included 3570 African American adults who were 18 years or over. This number was composed of 2299 women and 1271 men. Polypharmacy (using ≥ 5 medications) and hyper-polypharmacy (using ≥ 10 medications) were the independent variables. Psychological distress was the dependent variable. Age, gender, socioeconomic status (education attainment, income, employment, and marital status), health care access (insurance status and usual place of care), and health status (multimorbidity and psychiatric disorders) were the covariates. Linear multivariable regression was applied to perform the data analysis. Results: Both polypharmacy and hyper-polypharmacy were associated with psychological distress. This association was significant after controlling for all the covariates. Conclusions: African Americans with polypharmacy, particularly those with hyper-polypharmacy, are experiencing higher levels of psychological distress, which itself is a known risk factor for poor adherence to medications. There is a need for a comprehensive evaluation of medications as well as screening for psychopathology in African Americans with multiple medical conditions.

Midlife Psychological Well-Being and its Impact on Cognitive Functioning Later in Life: An Observational Study Using a Female British Birth Cohort

BACKGROUND

There is growing interest in public health strategies to modify dementia risk in midlife to reduce the burden of cognitive impairment in subsequent decades. Risk reduction messages should include key recommendations for women in response to the high prevalence of dementia observed in this population. Midlife is a critical period for dementia-related brain changes and psychosocial crises. Psychological well-being can improve resilience to crises, yet it is not well understood with respect to dementia risk reduction.

OBJECTIVE

This study aimed to examine the association between midlife psychological well-being and cognitive function in later life in women.

METHODS

The study included 703 women from the British 1946 birth cohort in the Medical Research Council's National Survey of Health and Development. Psychological well-being at 52 years was assessed using the Ryff Scales of Psychological Well-being over six dimensions: autonomy, environmental mastery, personal growth, positive relations with others, purpose in life, and self-acceptance. Cognitive function at 69 years was measured using the Addenbrooke's Cognitive Examination, Third Edition.

RESULTS

After controlling for cognitive ability at eight years, educational attainment by 26 years, occupational attainment and marital status by 53 years, depression, smoking, and physical exercise at 60-64 years, there was a significant association between greater personal growth and lower self-acceptance at 52 years, and better cognition at 69 years. However, there was no association between cognition and the other four Ryff scales.

CONCLUSION

Most aspects of midlife psychological well-being, except for personal growth and self-acceptance, were not prospectively associated with cognition.

Dietary glycaemic index and cognitive function: prospective associations in adults of the 1946 British birth cohort

Objective

Evidence suggests that the rate of glucose release following consumption of carbohydrate-containing foods, defined as the glycaemic index (GI), is inversely associated with cognitive function. To date, most of the evidence stems from either single-meal studies or highly heterogeneous cohort studies. We aimed to study the prospective associations of diet GI at age 53 years with outcomes of verbal memory and letter search tests at age 69 years and rate of decline between 53 and 69 years.

Design

Longitudinal population-based birth cohort study.

Setting

MRC National Survey for Health and Development.

Participants

Cohort members (n 1252).

Results

Using multivariable linear and logistic regression, adjusted for potential confounders, associations of higher-GI diet with lower verbal memory, lower letter search speed and lower number of hits in a letter search test were attenuated after adjustments for cognitive ability at age 15 years, educational attainment, further training and occupational social class. No association was observed between diet GI at 53 years and letter search accuracy or speed–accuracy trade-off at 69 years, or between diet GI at 53 years and rate of decline between 53 and 69 years in any cognitive measure.

Conclusions

Diet GI does not appear to predict cognitive function or decline, which was mainly explained by childhood cognitive ability, education and occupational social class. Our findings confirm the need for further research on the association between diet and cognition from a life-course perspective.

Using a birth cohort to study brain health and preclinical dementia: recruitment and participation rates in Insight 46

OBJECTIVE

Identifying and recruiting people with early pre-symptomatic Alzheimer's disease to neuroimaging research studies is increasingly important. The extent to which results of these studies can be generalised depends on the recruitment and representativeness of the participants involved. We now report the recruitment and participation patterns from a neuroscience sub-study of the MRC National Survey of Health and Development, "Insight 46". This study aimed to recruit 500 participants for extensive clinical and neuropsychological testing, and neuroimaging. We investigate how sociodemographic factors, health conditions and health-related behaviours predict participation at different levels of recruitment.

RESULTS

We met our target recruitment (n = 502). Higher educational attainment and non-manual socio-economic position (SEP) were consistent predictors of recruitment. Health-related variables were also predictive at every level of recruitment; in particular higher cognition, not smoking and better self-rating health. Sex and APOE-e4 status were not predictors of participation at any level. Whilst recruitment targets were met, individuals with lower SEP, lower cognition, and more health problems are under-represented in Insight 46. Understanding the factors that influence recruitment are important when interpreting results; for Insight 46 it is likely that health-related outcomes and life course risks will under-estimate those seen in the general population.

Childhood adversity and DNA methylation in two population-based cohorts

Childhood adversity affects later health, but the underlying molecular mechanisms are unclear. Although there is some evidence from animal models and case-control studies of a role for DNA methylation, evidence from human population-based studies is limited. In two cohorts (mothers from the Avon Longitudinal Study of Parents and Children, ALSPAC, n = 780 and women from the MRC National Survey of Health and Development, NSHD, n = 552), we assessed the association of seven adverse childhood experiences (ACEs: parental physical illness, parental mental illness, parental death, parental separation, suboptimal maternal bonding, childhood illness and child maltreatment) as well as their combination (ACE score) with genome-wide DNA methylation levels measured using the Illumina Infinium HumanMethylation450 BeadChip in peripheral blood at mean age 47 years (ALSPAC) and in buccal cells at age 53 years (NSHD). CpG sites with a genome-wide false discovery rate (FDR) below 0.05 and differentially methylated regions (DMRs) with one-step Šidák correction p-values below 0.05 in each cohort were examined in the other cohort. No individual CpG sites replicated across cohorts. However, nine DMRs replicated across cohorts respectively associated with the ACE score (one region), parental mental illness (two regions), parental physical illness (three regions) and parental death (three regions). These observations indicate that some adverse childhood experiences, notably those related to parental health, may leave imprints on peripheral DNA methylation that persist to mid-life.

Lifetime affective problems and later-life cognitive state: Over 50 years of follow-up in a British birth cohort study

BACKGROUND

Affective problems increase the risk of dementia and cognitive impairment, yet the life course dimension of this association is not clearly understood. We aimed to investigate how affective problems across the life course relate to later-life cognitive state.

METHODS

Data from 1269 participants from the Medical Research Council National Survey of Health and Development (NSHD, the British 1946 birth cohort) were used. Prospectively-assessed measures of affective symptoms spanning ages 13-69 and categorised into case-level thresholds. Outcomes consisted of a comprehensive measure of cognitive state (Addenbrooke's Cognitive Examination (ACE-III)), verbal memory, and letter search speed and accuracy at age 69.

RESULTS

Complementary life course models demonstrated that having 2 or more case-level problems across the life course was most strongly associated with poorer cognitive outcomes, before and after adjusting for sex, childhood cognition, childhood and midlife occupational position and education.

LIMITATIONS

A disproportionate loss to follow-up of those who had lower childhood cognitive scores may have led to underestimation of the strength of associations.

DISCUSSION

Using a population-based prospective study we provide evidence that recurrent lifetime affective problems predicts poorer later-life cognitive state, and this risk can be already manifest in early old age (age 69). Our findings raise the possibility that effective management to minimise affective problems reoccurring across the life course may reduce the associated risk of cognitive impairment and decline.

Assessing the relative importance of correlates of loneliness in later life. Gaining insight using recursive partitioning

OBJECTIVES

Improving the design and targeting of interventions is important for alleviating loneliness among older adults. This requires identifying which correlates are the most important predictors of loneliness. This study demonstrates the use of recursive partitioning in exploring the characteristics and assessing the relative importance of correlates of loneliness in older adults.

METHOD

Using exploratory regression trees and random forests, we examined combinations and the relative importance of 42 correlates in relation to loneliness at age 68 among 2453 participants from the birth cohort study the MRC National Survey of Health and Development.

RESULTS

Positive mental well-being, personal mastery, identifying the spouse as the closest confidant, being extrovert and informal social contact were the most important correlates of lower loneliness levels. Participation in organised groups and demographic correlates were poor identifiers of loneliness. The regression tree suggested that loneliness was not raised among those with poor mental wellbeing if they identified their partner as closest confidante and had frequent social contact.

CONCLUSION

Recursive partitioning can identify which combinations of experiences and circumstances characterise high-risk groups. Poor mental wellbeing and sparse social contact emerged as especially important and classical demographic factors as insufficient in identifying high loneliness levels among older adults.

Lifetime cognition and late midlife blood metabolites: findings from a British birth cohort

Maintenance of healthy cognitive ageing is vital for independence and wellbeing in the older general population. We investigated the association between blood metabolites and cognitive function and decline. Participants from the MRC National Survey of Health and Development (NSHD, the British 1946 birth cohort) were studied; 233 nuclear magnetic resonance circulating metabolite measures were quantified in 909 men and women at ages 60-64. Short-term and delayed verbal memory and processing speed were concurrently assessed and these tests were repeated at age 69. Linear regression analyses tested associations between metabolites and cognitive function at ages 60-64, and changes in these measures by age 69, adjusting for childhood cognition, education, socio-economic status and lifestyle factors. In cross-sectional analyses, metabolite levels, particularly fatty acid composition and different lipid sub-classes, were associated with short-term verbal memory (4 measures in females and 11 measures in the whole sample), delayed verbal memory (2 measures in females) and processing speed (8 measures in males and 2 measures in the whole sample) (p < 0.002). One metabolite was associated with change in cognition in females. Most of the observed associations were attenuated after adjustment for childhood cognition and education. A life course perspective can improve the understanding of how peripheral metabolic processes underlie cognitive ageing.

Expectations for future care provision in a population-based cohort of baby-boomers

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Over 2000 baby-boomers were asked who they expect will provide their social care, should they need it in the future.

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3 in 4 people with a living child expect them to meet any future care needs.

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1 in 5 expect their needs to be met by a friend or by formal care services, rising to 3 in 4 people without a child.

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Low mid-life social contact is linked with greater expectation of formal care.

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Chronic conditions and functional limitations are not related to expectations.

Objective

We describe sources expected to provide for future care needs among baby-boomers in their late sixties and examine how expectations vary according to earlier health and social experiences. We hypothesised that greater integration in social relationships across adulthood is associated with greater expectation of informal care, and that greater morbidity over a longer time period is associated with greater expectation of formal care.

Method

The MRC National Survey of Health and Development, a population-based birth cohort study set in mainland Britain, provided data on care expectations for 2135 participants aged 68–69. The outcome was who, besides the partner or spouse, is expected to provide for the future care needs, coded as adult children, other relatives, friends/neighbours, paid/professional care, or no one. Adult children were taken as the reference category and the latter two categories were combined as ‘formal care’ in the multiple regression analysis.

Results

91% had an adult child, of whom 74% expected them to provide care if needed, and 11% expected formal care. The latter rose to 33% of those with no adult children. Geographical distance to adult children (over 25 miles) was strongly correlated with expectations but, independently of this, lack of someone to help in a crisis from midlife onwards and low social contact were associated with expecting formal care. Expectations did not differ by number of chronic conditions, functional limitations or longstanding illness from age 60 + .

Conclusion

Those lacking social relationships in midlife onwards and those living further from adult children are more likely to expect formal help with their future care needs. As personal care needs are projected to rise with population ageing and families are increasingly expected to provide for these needs, initiatives to remove barriers to smaller distances between ageing parents and their children and to support and maintain high-quality family relationships across the life course should be considered.

Lifetime cigarette smoking and chronic widespread and regional pain in later adulthood: evidence from the 1946 British birth cohort study

OBJECTIVE

To examine whether different lifetime patterns of cigarette smoking are associated with chronic widespread pain (CWP) and chronic regional pain (CRP) at age 68.

DESIGN

Prospective cohort study.

SETTING

England, Scotland and Wales.

PARTICIPANTS

Up to 2347 men and women from the Medical Research Council National Survey of Health and Development, who have been followed up since birth in 1946 and provided sufficient information on cigarette smoking across adulthood to be classified as never smoker, predominantly non-smoker, predominantly smoker or lifelong smoker and pain assessment at age 68.

PRIMARY OUTCOME MEASURES

Pain was self-reported at age 68, and CWP was defined according to American College of Rheumatology criteria. Participants who reported having pain for ≥3 months but who did not meet the CWP definition were classified as having CRP; those who reported pain which had lasted for <3 months were classified as 'other' pain. No pain was the reference group.

RESULTS

Findings from multinomial logistic regression models indicated that compared with never smokers, predominantly non-smokers, predominantly smokers and lifelong smokers all had an increased risk of CWP; relative risk ratios=1.70(95% CI 1.16 to 2.49); 2.10(95% CI 1.34 to 3.28) and 1.88(95% CI 0.99 to 3.57), respectively, after adjusting for sex, own occupational class, educational level, body mass index, leisure time physical activity, alcohol intake, long-standing illness and symptoms of anxiety and depression. No association was observed between smoking history and CRP or other pain.

CONCLUSIONS

These results suggest that exposure to cigarette smoking at any stage in adulthood was associated with higher risk of CWP in later adulthood; highlighting the ongoing importance of smoking prevention programmes. It also suggests that assessment of lifetime smoking behaviour may be more useful in identifying those at greater risk of CWP in later life than assessment of current smoking status.

Adolescent affective symptoms and mortality

BACKGROUND

Little is known about the relationship between adolescent affective problems (anxiety and depression) and mortality.AimsTo examine whether adolescent affective symptoms are associated with premature mortality, and to assess whether this relationship is independent of other developmental factors.

METHOD

Data (n = 3884) was from Britain's oldest birth cohort study - the National Survey of Health and Development. Adolescent affective symptoms were rated by teachers at ages 13 and 15 years: scores were summed and classified into three categories: mild or no, moderate and severe symptoms (1st-50th, 51st-90th and 91st-100th percentiles, respectively). Mortality data were obtained from national registry data up to age 68 years. Potential confounders were parental social class, childhood cognition and illness, and adolescent externalising behaviour.

RESULTS

Over the 53-year follow-up period, 12.2% (n = 472) of study members died. Severe adolescent affective symptoms were associated with an increased rate of mortality compared with those with mild or no symptoms (gender adjusted hazard ratio 1.76, 95% CI 1.33-2.33). This association was only partially attenuated after adjustment for potential confounders (fully adjusted hazard ratio 1.61, 95% CI 1.20-2.15). There was suggestive evidence of an association across multiple causes of death. Moderate symptoms were not associated with mortality.

CONCLUSIONS

Severe adolescent affective symptoms are associated with an increased rate of premature mortality over a 53-year follow-up period, independent of potential confounders. These findings underscore the importance of early mental health interventions.Declaration of interestNone.

Motor performance in early life and participation in leisure-time physical activity up to age 68 years

BACKGROUND

This study examined associations between motor performance in early life and leisure-time physical activity (LTPA) participation across adulthood, and whether these changed with age.

METHODS

Data were from 2526 participants from the Medical Research Council National Survey of Health and Development. Motor indicators were mother-reported ages at first standing and walking, teacher-rated games ability at age 13, and finger- and foot-tapping speed at age 15. LTPA was reported at ages 36, 43, 53, 60-64, and 68 years and classed at each age as none, moderate (1-4/mo), or regular (≥5/mo). Associations were examined using mixed-effects Poisson regression models with robust error variance.

RESULTS

Better ability at games and faster tapping speed were associated with more frequent participation in LTPA across adulthood, for example, fully adjusted relative risk of regular LTPA across adulthood (vs none) for above-average ability (vs below average or average) = 1.46 (95% CI 1.32, 1.61); and per 10-unit higher number of finger-taps/15 seconds = 1.04 (95% CI 1.02, 1.07). These associations did not vary by age (P ≥ .33 for interactions with age at LTPA). Ages at reaching motor milestones were not associated with LTPA (eg, fully adjusted relative risk of regular LTPA across adulthood for walking ≤10 and ≥18 months (vs 11-17 months) were 1.01 (95% CI 0.86, 1.20) and 0.89 (95% CI 0.75, 1.06) respectively.

CONCLUSIONS

Better ability at games and faster tapping speed in adolescence were associated with greater participation in LTPA throughout adult life; from age 36 up to age 68. Childhood motor skill interventions may therefore have the potential to promote lifelong LTPA.

A dietary pattern derived using B-vitamins and its relationship with vascular markers over the life course

Background

Diet may influence vascular function through elevated homocysteine (Hcy) concentrations. However the relationship between dietary patterns (DP), characterised by Hcy and its associated nutrients is unknown.

Objective

To identify a DP characterised by plasma Hcy, dietary folate and dietary vitamin B12, and examine its associations with two markers of vascular function: carotid intima-media thickness (cIMT) and pulse wave velocity (PWV).

Methods

1562 participants of the MRC National Survey of Health and Development (NSHD), a British birth cohort, with dietary data measured at least once between 36 and 60–64 years, and cIMT or PWV measured at 60–64 years were included. DPs were derived using reduced rank regression with three intermediate variables: 1) plasma Hcy (μmol/L) 2) folate intake (μg/1000 kcal) 3) vitamin B12 intake (μg/1000 kcal). Multiple regression models assessed associations between the derived DP z-scores and vascular function adjusting for dietary misreporting, socioeconomic position, BMI, smoking, physical activity and diabetes.

Results

A DP explaining the highest amount of shared variation (4.5%) in plasma Hcy, dietary folate and dietary vitamin B12 highly correlated with folate (r = 0.96), moderately correlated with vitamin B12 (r = 0.27), and weakly correlated with Hcy (r = 0.10). This “high B-vitamin” DP (including folate) was characterised by high intakes of vegetables, fruit and low fibre breakfast cereal, and low intakes of processed meat, white bread, sugar and preserves. No associations were observed between DP z-scores and vascular function at any time point following adjustment for covariates.

Conclusion

This study explored a specific hypothesised pathway linking diet to vascular function. Although we found no consistent evidence for an association between a high B-vitamin DP and vascular function, we did observe an association with CRP and triglycerides in secondary analyses. Further analyses using strongly correlated and biologically relevant intermediate variables are required to refine investigations into diet and CVD in longitudinal cohort data.

Can measures of physical performance in mid-life improve the clinical prediction of disability in early old age? Findings from a British birth cohort study

BACKGROUND

Poor performance in physical tests such as grip strength and walking speed is a risk factor for disability in old age, although whether such measures improve the discrimination of clinical prediction models when traditional clinical risk factors are already known is not clear. The prevalence of disability in mid-life is relatively low and hence screening in this age group may present an opportunity for early identification of those at increased future risk who may benefit most from preventative interventions.

METHODS

Data were drawn from two waves of the Medical Research Council National Survey of Health and Development. We examined whether several chronic conditions, poor health behaviours and lower scores on three measures of physical performance (grip strength, chair rise speed and standing balance time) at age 53 were associated with self-reported mobility and/or personal care disability at age 69. We used the area under the curve statistic (AUC) to assess model discrimination.

RESULTS

At age 69, 44% (826/1855) of participants reported mobility and/or personal care disability. Our final clinical prediction model included sex, knee osteoarthritis, taking 2+ medications, smoking, increased BMI and poor performance in all three physical tests, with an AUC of 0.740 compared with 0.708 for a model which did not include the performance measures.

CONCLUSION

Measures of physical performance in midlife improve discrimination in clinical prediction models for disability over 16 years. Importantly, these and similar measures are also potential targets of future diet, exercise and pharmacological intervention in mid-life.

Are BMI and inflammatory markers independently associated with physical fatigability in old age?

Background

Obesity and chronic low-grade inflammation have both been implicated in the onset of physical fatigue. However, few studies have investigated the independence of these associations in older community-dwelling populations. We therefore aimed to investigate the associations of body mass index (BMI) and inflammatory markers at age 60–64 with perceived physical fatigability at age 68 and to assess whether any such associations were independent of each other and potential confounding factors. A secondary aim was to investigate whether any association with BMI extended back into earlier adulthood.

Methods

Participants of the MRC National Survey of Health and Development (N = 1580) had BMI and levels of interleukin-6 (IL-6) and C-reactive protein (CRP) measured during clinical assessments at age 60–64. These were related to self-perceived physical fatigability assessed at age 68 using the Pittsburgh Fatigability Scale (PFS) (total score:0 (no physical fatigue)–50 (extreme physical fatigue)).

Resuts

Women had higher mean PFS scores than men (mean (SD): 16.0 (9.1) vs 13.2 (8.9), p < 0.01). In sex-adjusted models, BMI, CRP and IL-6 were each associated with PFS scores. When all three factors were included in the same model, BMI and IL-6 remained associated with PFS scores whereas CRP did not. After adjustment for a range of potential confounders, associations of BMI and IL-6 with PFS scores were still evident; fully adjusted differences in mean PFS score = 3.41 (95% CI: 0.59, 6.24) and 1.65 (0.46, 2.84) for underweight and obese participants when compared with normal weight and, 2.78 (1.65, 3.91) when comparing those with an IL-6 of 2.51–8.49 pg/mL with levels <1.50.

Conclusions

BMI and inflammation may both be suitable targets for intervention to reduce the burden of physical fatigability in later life. Further, interventions that target both obesity and elevated levels of IL-6 are likely to be more effective than those focusing on only one.