Medical Research Council National Survey Research Articles

Characterising and differentiating cognitive and motor speed in older adults: structural equation modelling on a UK longitudinal birth cohort

ObjectivesInformation processing speed (IPS) has been proposed to be a key component in healthy ageing and cognitive functioning. Yet, current studies lack a consistent definition and specific influential characteristics. This...

Rest and stress aortic flow analysis by CMR in MyoFit46

Abstract Background Aortic stiffness is a strong predictor of future cardiovascular events and all-cause mortality. Aortic stiffness has never been measured during adenosine stress perfusion before, and may provide valuable relationship about this relationship. Aim To investigate if there are differences between aortic stiffness and conditions of rest and stress perfusion, in an older age-homogenous population-based cohort. Methods 203 participants from the longitudinal 1946 Medical Research Council National Survey of Health and Development British birth cohort were included. Cardiovascular Magnetic Resonance (CMR) imaging was performed at rest and during adenosine stress perfusion. 3 established and validated biomarkers of aortic stiffness were reported - pulse wave velocity, distensibility and beta stiffness, at rest and stress perfusion. All variables were non-normally distributed, therefore the Wilcoxon signed-rank test was used to look for significant differences between rest and stress. Results Aortic stiffness increased significantly during adenosine stress perfusion, shown by all biomarkers of aortic stiffness used: pulse wave velocity (p = <0.001), distensibility (p = <0.001), and beta stiffness (p = <0.001). However, the aortas of participants with a higher resting aortic stiffness at baseline were less dynamic (little if any aortic stiffness change with stress) when compared to those with low resting aortic stiffness. Conclusion It is feasible to measure aortic stiffness during adenosine stress perfusion. In healthy aortas, aortic stiffness increases in the acute phase of adenosine stress suggesting a new potential mechanism for the body response to adenosine – peripheral chemoreceptor reflex activation. Stiffer arteries at baseline are less modifiable and stress aortic flow CMR has the potential to identify these persons permitting early targeted therapy. Change in aortic stiffness, measured by stress aortic flow CMR is therefore a potential non-invasive biomarker of aortic health.

Skylark Wiki: Accessing research data of the MRC National Survey of Health and Development

Background & IntroductionThe Medical Research Council National Survey of Health and Development (NSHD) is the oldest and longest-running of the British birth cohort studies. In 2018 we launched the Skylark Wiki, a central metadata repository and the first port of call for any data sharing queries. In 2023 we utilised the HDRUK funding initiative to work with our advisory group and research community to improve the transparency of our data access process and make the content more accessible. MethodsWe conducted a focus group session with the NSHD Participant Advisory Panel to understand their views on the data sharing process and whether the information we provided them, sufficiently explained how their data are shared. We also sent out a questionnaire to all Skylark Users to identify areas of improvement. Lastly, we undertook an audit of the website’s content and used Google Analytics to see how Users navigated across the site. Combining all this information we identified areas requiring improvements, from the point of view of our stakeholders, and comparing these to the requirements indicated in the HDRUK Transparency Standards we mapped out updates to the Skylark Wiki. The work was carried out by an external agency (Aubergine262 Ltd). ResultsTo increase transparency and searchability, we improved the flow diagram of the data sharing process to include links to the relevant web pages. We also created guidance to explain why the information in the data request application form is being asked. As feedback from Skylark Users suggested difficulties in finding the required information, the navigation has been updated. We have also changed the layout of the front page to include navigation boxes that takes users straight to the content. The NSHD Advisory Panel reinforced the notion of trust that study participants place in the study and its approach to data sharing. They confirmed the information provided on data sharing was adequate and appreciated that this information was placed on the main study website (https://nshd.mrc.ac.uk/) for their benefit. Initial feedback from Users indicates that it is easier to find information on the website. We will keep monitoring access to the website, the number of queries, and data access requests to evaluate long-term benefits. We have changed the sitemap and added in large link boxes, to make it easier to find the different sections. We hope this will improve the searchability of the site so users can find information they required. We hope this will therefore lead to fewer emails and correspondence between the data sharing team and users. We have also updated the flow diagram of the data sharing process to include links to the web pages which are related to that section. We hope this will help the users find the information they require. ConclusionsThe new Skylark data-sharing website supports easier navigation providing a better User experience. In return, this should lead to fewer queries from Users. The website will be easier to maintain having changed the content management system from a Wiki to WordPress. WordPress requires less technical knowledge, allowing more staff to contribute to regular maintenance. References Skylark data-sharing website: https://skylark.ucl.ac.uk/NSHD/ Aubergine: https://www.aubergine262.com/

Associations Between Midlife Anticholinergic Medication Use and Subsequent Cognitive Decline: A British Birth Cohort Study.

Anticholinergic medication use is associated with cognitive decline and incident dementia. Our study, a prospective birthcohortanalysis, aimed to determine if repeated exposure to anticholinergic medicationswas associated with greater decline, and whether decline was reversed with medication reduction. From the Medical Research Council (MRC) National Survey of Health and Development, a British birth cohort with all participants born in a single week of March 1946, we quantified anticholinergic exposure between ages 53 and 69 years using the Anticholinergic Cognitive Burden Scale (ACBS). We used multinomial regression to estimate associations with global cognition, quantified bythe Addenbrooke's Cognitive Examination, 3rd Edition (ACE-III). Longitudinal associations between ACBS and cognitive test results (Verbal memory quantifiedby theWord Learning Test [WLT], and processing speed quantified by theTimed Letter Search Task [TLST]) at three time points (age 53, 60-64 and 69) were assessed using mixed and fixed effects linear regression models. Analyses were adjusted for sex, childhood cognition, education, chronic disease count and severity, and mental health symptoms. Anticholinergic exposure was associated cross-sectionally with lower ACE-III scores at age 69, with the greatest effects in those with high exposure at ages 60-64 (mean difference - 2.34, 95% confidence interval [CI] - 3.51 to - 1.17). Longitudinally, both mild-moderate and high ACBS scores were linked to lower WLT scores, again with high exposure showing larger effects (mean difference with contemporaneous exposure - 0.90, 95% CI - 1.63 to - 0.17; mean difference with lagged exposure - 1.53, 95% CI - 2.43 to - 0.64). Associations remained in fixed effects models (mean difference with contemporaneous exposure -1.78, 95% CI -2.85 to - 0.71; mean difference with lagged exposure - 2.23, 95% CI - 3.33 to - 1.13). Associations with TLST were noted only in isolated contemporaneous exposure (mean difference - 13.14, 95% CI - 19.04 to - 7.23; p<0.01). Anticholinergic exposure throughout mid and later life was associated with lower cognitive function. Reduced processing speed was associated only with contemporaneous anticholinergic medication use, and not historical use. Associations with lower verbal recall were evident with both historical and contemporaneous use of anticholinergic medication, and associations with historical use persisted in individuals even when their anticholinergic medication use decreased over the course of the study.

Associations between life course longitudinal growth and hip shapes at ages 60–64 years: evidence from the MRC National Survey of Health and Development

ObjectiveWe sought to examine associations between height gain across childhood and adolescence with hip shape in individuals aged 60–64 years from the Medical Research Council National Survey of Health and...

Investigating associations of multiple common infections with brain structure and white matter lesions: findings from prospective neuroimaging studies

AbstractBackgroundEvidence for a role of common infections in neurodegenerative and cerebrovascular diseases is conflicting, and the extent to which pathogen exposure associates with subclinical imaging markers of these diseases is unclear. We aimed to investigate associations between a panel of serological measures characterising exposure to common pathogens – selected based on their relevance to public health – and brain volume, hippocampal volume, and white matter lesions in two population‐based cohorts in the UK.MethodSerology and imaging data were available for 1371 participants across two studies: the UK Biobank (N = 935, mean age(SD)[years] = 55.3(7.7) at serology; 63.8(7.7) at imaging) and the Medical Research Council National Survey of Health and Development [N = 436, mean age(SD) [years] = 63.3(1.1) years at serology; 70.7(0.7) years at imaging). Serology measures included a) serostatuses of 17 pathogens, b) total proportion of 17 pathogens exposed to, and c) total proportion of 11 neurotropic pathogens exposed to (Table 1). Associations between serology measures and outcomes (brain volume, hippocampal volume, and white matter lesion volume) were tested using linear regression. Regression models included adjustments for total intracranial volume and clinic information (basic models), and age, sex, ethnicity, education, socioeconomic position and lifestyle factors (Figure 1). Findings across cohorts were meta‐analysed using random‐effects models. The present study will be expanded to include an additional cohort (Southall and Brent Revisited,N≤1200) to add more precision for identifying associations.ResultSeropositivity to seven pathogens associated with an outcome in basic models, and four in fully‐adjusted models: seropositivity to JC virus was associated with smaller brain volumes, Epstein‐Barr virus with larger brain volumes, Merkel cell virus with larger hippocampal volumes and fewer white matter lesions, and C.trachomatis with fewer white matter lesions (Figure 2). Neurotropic pathogen burden scores associated with smaller hippocampal volumes in basic models, but no associations were seen for either pathogen burden score in fully‐adjusted models.ConclusionWe found some evidence of both positive and negative associations between common infections and imaging markers of subclinical cerebrovascular disease and neurodegeneration, with no evidence of relationships with pathogen burden. This work highlights key relationships for further investigation, which may reveal novel pathways associated with brain structure and cerebrovascular pathology.

Associations between diabetes status and grip strength trajectory sub-groups in adulthood: findings from over 16 years of follow-up in the MRC National Survey of Health and Development

BackgroundCross-sectional studies suggest a relationship between diabetes status and weaker grip strength (GS) in adulthood and limited evidence from longitudinal studies has focussed on the association with average change in GS. We aimed to investigate whether diabetes status was related to membership of distinct GS trajectories in mid-to-late adulthood in 2,263 participants in the Medical Research Council National Survey of Health and Development.MethodsGrip strength (kg) was measured at 53, 60–64 and 69 years. Pre-/diabetes was defined at 53 years based on HbA1c > 5.6% and/or doctor-diagnosis of diabetes. Sex-specific latent class trajectory models were developed and multinomial logistic regression was used to investigate the association between pre-/diabetes status and membership into GS trajectory classes.ResultsFor both males and females, a 3-class solution (‘High’, ‘Intermediate’, ‘Low’) provided the best representation of the GS data and the most plausible solution. There was no evidence that pre-/diabetes status was associated with class membership in either sex: e.g., adjusted odds ratios of being in the ‘Low’ class (vs. ‘High’) for males with pre-/diabetes (vs. no-diabetes) was 1.07 (95% CI:0.45,2.55).ConclusionUsing a flexible data-driven approach to identify GS trajectories between 53 and 69 years, we observed three distinct GS trajectories, all declining, in both sexes. There was no association between pre-/diabetes status at 53 years and membership into these GS trajectories. Understanding the diabetes status―GS trajectories association is vital to ascertain the consequences that projected increases in pre-/diabetes prevalence’s are likely to have.

Early childhood lower respiratory tract infection and premature adult death from respiratory disease in Great Britain: a national birth cohort study

Lower respiratory tract infections (LRTIs) in early childhood are known to influence lung development and lifelong lung health, but their link to premature adult death from respiratory disease is unclear. We aimed to estimate the association between early childhood LRTI and the risk and burden of premature adult mortality from respiratory disease. This longitudinal observational cohort study used data collected prospectively by the Medical Research Council National Survey of Health and Development in a nationally representative cohort recruited at birth in March, 1946, in England, Scotland, and Wales. We evaluated the association between LRTI during early childhood (age <2 years) and death from respiratory disease from age 26 through 73 years. Early childhood LRTI occurrence was reported by parents or guardians. Cause and date of death were obtained from the National Health Service Central Register. Hazard ratios (HRs) and population attributable risk associated with early childhood LRTI were estimated using competing risks Cox proportional hazards models, adjusted for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and smoking at age 20-25 years. We compared mortality within the cohort studied with national mortality patterns and estimated corresponding excess deaths occurring nationally during the study period. 5362 participants were enrolled in March, 1946, and 4032 (75%) continued participating in the study at age 20-25 years. 443 participants with incomplete data on early childhood (368 [9%] of 4032), smoking (57 [1%]), or mortality (18 [<1%]) were excluded. 3589 participants aged 26 years (1840 [51%] male and 1749 [49%] female) were included in the survival analyses from 1972 onwards. The maximum follow-up time was 47·9 years. Among 3589 participants, 913 (25%) who had an LRTI during early childhood were at greater risk of dying from respiratory disease by age 73 years than those with no LRTI during early childhood (HR 1·93, 95% CI 1·10-3·37; p=0·021), after adjustment for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and adult smoking. This finding corresponded to a population attributable risk of 20·4% (95% CI 3·8-29·8) and 179 188 (95% CI 33 806-261 519) excess deaths across England and Wales between 1972 and 2019. In this prospective, life-spanning, nationally representative cohort study, LRTI during early childhood was associated with almost a two times increased risk of premature adult death from respiratory disease, and accounted for one-fifth of these deaths. National Institute for Health and Care Research Imperial Biomedical Research Centre, Royal Brompton and Harefield National Health Service (NHS) Foundation Trust, Royal Brompton and Harefield Hospitals Charity and Imperial College Healthcare NHS Trust, UK Medical Research Council.

A comprehensive assessment of age at menopause with well-characterized cognition at 70 years: A population-based British birth cohort

ObjectivesAssociations between age at menopause and cognition post-menopause are examined to determine whether relationships are stronger for certain cognitive domains. Study designWomen from the Medical Research Council National Survey of Health and Development and its neuroscience sub-study, Insight 46, were included if they had known age at menopause (self-reported via questionnaire) and complete cognitive outcome data at age 69 (n = 746) or at Insight 46 wave I (n = 197). Multivariable linear regression analyses adjusting for life course confounders were run; interactions with menopause type (natural/surgical) and APOE-ε4 status were examined; and the potential contribution of hormone therapy was assessed. Main outcome measuresCognitive measures were standardized Addenbrooke's Cognitive Examination - third edition total and sub-domain scores at age 69 (whole cohort) and Preclinical Alzheimer's Cognitive Composite total and sub-test scores at age ~70 (Insight 46). ResultsOlder age at menopause was associated with better performance across all outcomes, most strongly for the Addenbrooke's Cognitive Examination memory and visuospatial function sub-domains, and the Preclinical Alzheimer's Cognitive Composite digit-symbol substitution test and face-name associative memory examination sub-tests. Adjusting for early-life factors attenuated all effect estimates, driven by childhood cognition, and accounting for menopause type revealed negative confounding for some outcomes. No significant interactions with menopause type or APOE-ε4 status were detected. Further adjustment for hormone therapy did not meaningfully alter the estimated effects. ConclusionsOlder age at menopause is associated with better later-life cognitive performance, particularly for visual processing and associative learning and memory domains. Childhood cognition was an important contributor.

One-Legged Balance Performance and Fall Risk in Mid and Later Life: Longitudinal Evidence From a British Birth Cohort

The one-legged balance test is widely used as a fall risk screening tool in both clinical and research settings. Despite rising fall prevalence in midlife, there is little evidence examining balance and fall risk in those aged <65 years. This study investigated the longitudinal associations between one-legged balance and the number of falls between ages 53 and 68 years. The study included 2,046 individuals from the Medical Research Council National Survey of Health & Development, a British birth cohort study. One-legged balance times (eyes open, maximum: 30 seconds) were assessed at ages 53 years (1999) and 60-64 years (2006-2010). Fall history within the last year (none, 1, ≥2) was self-reported at ages 60-64 years and 68 years (2014). Multinomial logistic regressions assessed the associations between balance and change in balance with subsequent falls. Models adjusted for anthropometric, socioeconomic, behavioral, health status, and cognitive indicators. Analysis occurred between 2019 and 2022. Balance performance was not associated with single falls. Better balance performance at age 53 years was associated with decreased risk of recurrent falls at ages 60-64 years and 68 years, with similar associations between balance at age 60-64 years and recurrent falls at age 68 years. Those with consistently lower balance times (<15 seconds) were at greater risk (RRR=3.33, 95% CI=1.91, 5.80) of recurrent falls at age 68 years in adjusted models than those who could balance for 30 seconds at ages 53 years and 60-64 years. Lower balance and consistently low or declining performance were associated with a greater subsequent risk of recurrent falls. Earlier identification and intervention of those with poor balance ability can help to minimize the risk of recurrent falls in aging adults.

Moderating Role of Cognitive Reserve Markers Between Childhood Cognition and Cognitive Aging: Evidence From the 1946 British Birth Cohort.

As the population ages, differences in cognitive abilities become more evident. We investigated key genetic and life course influences on cognitive state at age 69 years, building on previous work using the longitudinal Medical Research Council National Survey of Health and Development (the British 1946 birth cohort). Multivariable regressions investigated the association between 4 factors: (1) childhood cognition at age 8 years; (2) a Cognitive Reserve Index (CRI) composed of 3 markers: (i) educational attainment by age 26 years, (ii) engagement in leisure activities at age 43 years, and (iii) occupation up to age 53 years; (3) reading ability assessed by the National Adult Reading Test (NART) at age 53 years; and (4) APOE genotype in relation to cognitive state measured at age 69 years with Addenbrooke's Cognitive Examination, third edition (ACE-III). We then investigated the modifying role of the CRI, NART, and APOE in the association between childhood cognition and the ACE-III. The analytical sample comprised 1,184 participants. Higher scores in childhood cognition, CRI, and NART were associated with higher scores in the ACE-III. We found that the CRI and NART modified the association between childhood cognition and the ACE-III: for 30 additional points in the CRI or 20 additional points in the NART, the simple slope of childhood cognition decreased by approximately 0.10 points (CRI = 70: marginal effects (MEs) 0.22, 95% CI 0.12-0.32, p < 0.001 vs CRI = 100: MEs 0.12, 95% CI 0.06-0.17, p < 0.001; NART = 15: MEs 0.22, 95% CI 0.09-0.35, p = 0.001, vs NART = 35: MEs 0.11, 95% CI 0.05-0.17, p < 0.001). The association between childhood cognition and the ACE-III was nonsignificant at high levels of the CRI or NART. Furthermore, the e4 allele of the APOE gene was associated with lower scores in the ACE-III (β = -0.71, 95% CI -1.36 to -0.06, p = 0.03) but did not modify the association between childhood cognition and cognitive state in later life. The CRI and NART are independent measures of cognitive reserve because both modify the association between childhood cognition and cognitive state.

Milk intake across adulthood and muscle strength decline from mid- to late life: the MRC National Survey of Health and Development.

Milk is a source of several nutrients which may be beneficial for skeletal muscle. Evidence that links lower milk intake with declines in muscle strength from midlife to old age is lacking. We used data from the Medical Research Council National Survey of Health and Development to test sex-specific associations between milk consumption from age 36 to 60-64 years, low grip strength (GS) or probable sarcopenia, and GS decline from age 53 to 69 years. We included 1340 men and 1383 women with at least one measure of both milk intake and GS. Milk intake was recorded in 5-d food diaries (aged 36, 43, 53 and 60-64 years), and grand mean of total, reduced-fat and full-fat milk each categorised in thirds (T1 (lowest) to T3 (highest), g/d). GS was assessed at ages 53, 60-64, and 69 years, and probable sarcopenia classified at the age of 69 years. We employed logistic regression to examine the odds of probable sarcopenia and multilevel models to investigate decline in GS in relation to milk intake thirds. Compared with T1, only T2 (58·76-145·25 g/d) of reduced-fat milk was associated with lower odds of sex-specific low GS at the age of 69 years (OR (95 % CI): 0·59 (0·37, 0·94), P = 0·03). In multilevel models, only T3 of total milk (≥ 237·52 g/d) was associated with stronger GS in midlife in men (β (95 % CI) = 1·82 (0·18, 3·45) kg, P = 0·03) compared with T1 (≤ 152·0 g/d), but not with GS decline over time. A higher milk intake across adulthood may promote muscle strength in midlife in men. Its role in muscle health in late life needs further examination.

Declining Levels and Bioavailability of IGF-I in Cardiovascular Aging Associate With QT Prolongation-Results From the 1946 British Birth Cohort.

BackgroundAs people age, circulating levels of insulin-like growth factors (IGFs) and IGF binding protein 3 (IGFBP-3) decline. In rat cardiomyocytes, IGF-I has been shown to regulate sarcolemmal potassium channel activity and late sodium current thus impacting cardiac repolarization and the heart rate-corrected QT (QTc). However, the relationship between IGFs and IGFBP-3 with the QTc interval in humans, is unknown.ObjectivesTo examine the association of IGFs and IGFBP-3 with QTc interval in an older age population-based cohort.MethodsParticipants were from the 1946 Medical Research Council (MRC) National Survey of Health and Development (NSHD) British birth cohort. Biomarkers from blood samples at age 53 and 60–64 years (y, exposures) included IGF-I/II, IGFBP-3, IGF-I/IGFBP-3 ratio and the change (Δ) in marker levels between the 60–64 and 53y sampled timepoints. QTc (outcome) was recorded from electrocardiograms at the 60–64y timepoint. Generalized linear multivariable models with adjustments for relevant demographic and clinical factors, were used for complete-cases and repeated after multiple imputation.ResultsOne thousand four hundred forty-eight participants were included (48.3% men; QTc mean 414 ms interquartile range 26 ms). Univariate analysis revealed an association between low IGF-I and IGF-I/IGFBP-3 ratio at 60–64y with QTc prolongation [respectively: β −0.30 ms/nmol/L, (95% confidence intervals −0.44, −0.17), p < 0.001; β−28.9 ms/unit (-41.93, −15.50), p < 0.001], but not with IGF-II or IGFBP-3. No association with QTc was found for IGF biomarkers sampled at 53y, however both ΔIGF-I and ΔIGF-I/IGFBP-3 ratio were negatively associated with QTc [β −0.04 ms/nmol/L (−0.08, −0.008), p = 0.019; β −2.44 ms/unit (-4.17, −0.67), p = 0.007] while ΔIGF-II and ΔIGFBP-3 showed no association. In fully adjusted complete case and imputed models (reporting latter) low IGF-I and IGF-I/IGFBP-3 ratio at 60–64y [β −0.21 ms/nmol/L (−0.39, −0.04), p = 0.017; β −20.14 ms/unit (−36.28, −3.99), p = 0.015], steeper decline in ΔIGF-I [β −0.05 ms/nmol/L/10 years (−0.10, −0.002), p = 0.042] and shallower rise in ΔIGF-I/IGFBP-3 ratio over a decade [β −2.16 ms/unit/10 years (−4.23, −0.09), p = 0.041], were all independently associated with QTc prolongation. Independent associations with QTc were also confirmed for other previously known covariates: female sex [β 9.65 ms (6.65, 12.65), p < 0.001], increased left ventricular mass [β 0.04 ms/g (0.02, 0.06), p < 0.001] and blood potassium levels [β −5.70 ms/mmol/L (−10.23, −1.18) p = 0.014].ConclusionOver a decade, in an older age population-based cohort, declining levels and bioavailability of IGF-I associate with prolongation of the QTc interval. As QTc prolongation associates with increased risk for sudden death even in apparently healthy people, further research into the antiarrhythmic effects of IGF-I on cardiomyocytes is warranted.

Study protocol: MyoFit46\u2014the cardiac sub-study of the MRC National Survey of Health and Development

BackgroundThe life course accumulation of overt and subclinical myocardial dysfunction contributes to older age mortality, frailty, disability and loss of independence. The Medical Research Council National Survey of Health and Development (NSHD) is the world’s longest running continued surveillance birth cohort providing a unique opportunity to understand life course determinants of myocardial dysfunction as part of MyoFit46–the cardiac sub-study of the NSHD.MethodsWe aim to recruit 550 NSHD participants of approximately 75 years+ to undertake high-density surface electrocardiographic imaging (ECGI) and stress perfusion cardiovascular magnetic resonance (CMR). Through comprehensive myocardial tissue characterization and 4-dimensional flow we hope to better understand the burden of clinical and subclinical cardiovascular disease. Supercomputers will be used to combine the multi-scale ECGI and CMR datasets per participant. Rarely available, prospectively collected whole-of-life data on exposures, traditional risk factors and multimorbidity will be studied to identify risk trajectories, critical change periods, mediators and cumulative impacts on the myocardium.DiscussionBy combining well curated, prospectively acquired longitudinal data of the NSHD with novel CMR–ECGI data and sharing these results and associated pipelines with the CMR community, MyoFit46 seeks to transform our understanding of how early, mid and later-life risk factor trajectories interact to determine the state of cardiovascular health in older age.Trial registration: Prospectively registered on ClinicalTrials.gov with trial ID: 19/LO/1774 Multimorbidity Life-Course Approach to Myocardial Health- A Cardiac Sub-Study of the MCRC National Survey of Health and Development (NSHD).

Childhood bradycardia associates with atrioventricular conduction defects in older age: a longitudinal birth cohort study

Abstract Background A high resting heart rate (RHR) has been associated with cardiovascular morbidity and mortality. However, little is known about the long-term effects of childhood bradycardia. Purpose This study aimed to explore the association between childhood bradycardia and later-life cardiac phenotype using longitudinal data from the 1946 Medical Research Council National Survey of Health and Development (NSHD) birth cohort. Methods RHR was recorded at ages 6 and 7 to provide the bradycardia exposure defined as a childhood RHR&amp;lt;75. Three outcomes were studied: i) echocardiographic data at 60–64 consisting of ejection fraction (EF), left ventricular mass index (LVmassi), myocardial contraction fraction index (MCFi) and E/e'; ii) electrocardiographic (ECG) evidence of atrio-ventricular (AV) conduction defects (Minnesota categories: 6-1, 6-2-1, 6-2-2, 6-2-3, 6-3, 6-8, 8-5-1, 8-5-2, 8-6-1, 8-6-2, 8-6-3 and 8-6-4) or ventricular conduction defects (any Minnesota group 7) by age 60–64; and iii) all-cause and cardiovascular mortality. Generalized linear models (glm) with gamma distribution were used for echocardiographic analyses, glms with binomial distribution for ECG analyses and Cox proportional hazards models for mortality. Adjustment was made for relevant demographic and health-related covariates, and for multiple testing. In order to account for within-subject correlated repeated measures at 6 and 7 years of age, mixed glms (glmms) were used as a sensitivity analysis. To explore any nonlinear relationships, we modeled each outcome as a sum of best fitting fractional polynomials of RHR at 6 and 7 (as continuous variables) and covariates using a “closed test procedure” with backward elimination. Results The number of participants included was: 4381 for mortality, 1631 for ECG and 1617 for echocardiography analyses. Childhood bradycardia was associated with male sex (p&amp;lt;0.0001) and higher BMI (p=0.009). In fully adjusted models, childhood bradycardia was associated with 2.91 higher odds of AV conduction defects (95% confidence interval [CI] 1.59–5.31, p=0.0005), even at a false discovery rate of 0.05. Associations persisted in random coefficients glmm models (odds ratio 2.50, 95% CI 1.01–4.31). The fractional polynomials analyses revealed that the log odds of AV conduction defects at 60–64 years of age were linearly associated with RHR at 7 years. There was no association between bradycardia in childhood and ventricular conduction defects, echocardiographic parameters or mortality outcomes. Conclusions Longitudinal data indicate that childhood bradycardia trebles the odds of having AV conduction defects, but does not influence mortality or heart size and function in older age. As one in three older adults with AV conduction defects will have been bradycardic in childhood, future research should concentrate on identifying children at risk, the potential mechanisms involved and whether AV blocking drugs accelerate nodal dysfunction. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): British Heart Foundation (MyoFit46 Special Programme Grant SP/20/2/34841)

Sex-related differences in whole brain volumes at age 70 in association with hyperglycemia during adult life

Longitudinal studies of the relationship between hyperglycemia and brain health are rare and there is limited information on sex differences in associations. We investigated whether glycosylated hemoglobin (HbA1c) measured at ages of 53, 60–64 and 69 years, and cumulative glycemic index (CGI), a measure of cumulative glycemic burden, were associated with metrics of brain health in later life.Participants were from Insight 46, a substudy of the Medical Research Council National Survey of Health and Development (NSHD) who undertook volumetric MRI, florbetapir amyloid-PET imaging and cognitive assessments at ages of 69–71. Analyses were performed using linear and logistic regression as appropriate, with adjustment for potential confounders. We observed a sex interaction between HbA1c and whole brain volume (WBV) at all 3 time points. Following stratification of our sample, we observed that HbA1c at all ages, and CGI were positively associated with lower WBV exclusively in females. HbA1c (or CGI) was not associated with amyloid status, white matter hyperintensities (WMHs), hippocampal volumes (HV) or cognitive outcomes in either sex.Higher HbA1c in adulthood is associated with smaller WBV at 69–71 years in females but not in males. This suggests that there may be preferential target organ damage in the brain for females with hyperglycemia.

Childhood growth and development and DNA methylation age in mid-life

BackgroundIn the first study of its kind, we examine the association between growth and development in early life and DNAm age biomarkers in mid-life.MethodsParticipants were from the Medical Research Council National Survey of Health and Development (n = 1376). Four DNAm age acceleration (AgeAccel) biomarkers were measured when participants were aged 53 years: AgeAccelHannum; AgeAccelHorvath; AgeAccelLevine; and AgeAccelGrim. Exposure variables included: relative weight gain (standardised residuals from models of current weight z-score on current height, and previous weight and height z-scores); and linear growth (standardised residuals from models of current height z-score on previous height and weight z-scores) during infancy (0–2 years, weight gain only), early childhood (2–4 years), middle childhood (4–7 years) and late childhood to adolescence (7–15 years); age at menarche; and pubertal stage for men at 14–15 years. The relationship between relative weight gain and linear growth and AgeAccel was investigated using conditional growth models. We replicated analyses from the late childhood to adolescence period and pubertal timing among 240 participants from The National Child and Development Study (NCDS).ResultsA 1SD increase in relative weight gain in late childhood to adolescence was associated with 0.50 years (95% CI 0.20, 0.79) higher AgeAccelGrim. Although the CI includes the null, the estimate was similar in NCDS [0.57 years (95% CI − 0.01, 1.16)] There was no strong evidence that relative weight gain and linear growth in childhood was associated with any other AgeAccel biomarker. There was no relationship between pubertal timing in men and AgeAccel biomarkers. Women who reached menarche ≥ 12 years had 1.20 years (95% CI 0.15, 2.24) higher AgeAccelGrim on average than women who reached menarche < 12 years; however, this was not replicated in NCDS and was not statistically significant after Bonferroni correction.ConclusionsOur findings generally do not support an association between growth and AgeAccel biomarkers in mid-life. However, we found rapid weight gain during pubertal development, previously related to higher cardiovascular disease risk, to be associated with older AgeAccelGrim. Given this is an exploratory study, this finding requires replication.

Bi-directional associations between religious attendance and mental health: findings from a British birth cohort study

BackgroundThere is evidence that religious attendance is associated with positive outcomes for mental health; however, there are few longitudinal studies, and even fewer, which take into account the possibility of...

Letter to the Editor: Landsbergis et al (2019) Titled "Work Exposures and Musculoskeletal Disorders Among Railroad Maintenance-of-Way Workers".

Letter to the Editor: Landsbergis et al (2019) Titled "Work Exposures and Musculoskeletal Disorders Among Railroad Maintenance-of-Way Workers".

From cohort to community: The emotional work of birthday cards in the Medical Research Council National Survey of Health and Development, 1946-2018.

The Medical Research Council National Survey of Health and Development (NSHD) is Britain’s longest-running birth cohort study. From their birth in 1946 until the present day, its research participants, or study members, have filled out questionnaires and completed cognitive or physical examinations every few years. Among other outcomes, the findings of these studies have framed how we understand health inequalities. Throughout the decades and multiple follow-up studies, each year the study members have received a birthday card from the survey staff. Although the birthday cards were originally produced in 1962 as a method to record changes of address at a time when the adolescent study members were potentially leaving school and home, they have become more than that with time. The cards mark, and have helped create, an ongoing evolving relationship between the NSHD and the surveyed study members, eventually coming to represent a relationship between the study members themselves. This article uses the birthday cards alongside archival material from the NSHD and oral history interviews with survey staff to trace the history of the growing awareness of importance of emotion within British social science research communities over the course of the 20th and early 21st centuries. It documents changing attitudes to science’s dependence on research participants, their well-being, and the collaborative nature of scientific research. The article deploys an intertextual approach to reading these texts alongside an attention to emotional communities drawing on the work of Barbara Rosenwein.