Childhood cognition and risk factors for cardiovascular disease in midadulthood: the 1958 British Birth Cohort Study

A longitudinal study of learning difficulties in adolescence and biomarkers of cardiometabolic risk in adulthood: A gendered pathways approach

OBJECTIVES

Little is known about the relationship between learning difficulties (LD) in adolescence and physical health in adulthood. This study investigates the gender-specific pathways through which LD is longitudinally associated with cardiometabolic risk in adulthood.

STUDY DESIGN

We used data from the National Longitudinal Study of Adolescent to Adult Health (N = 11,342). To assess cardiometabolic risk, 11 biomarkers related to cardiovascular functioning, glucose metabolism, lipid metabolism, and inflammation were utilized.

METHODS

We first estimated the association between LD in adolescence and cardiometabolic risk in adulthood. Then, we examined whether this association is mediated by educational attainment and body mass index (BMI). Finally, we employed a moderated mediation model to determine whether gender moderates these mediation patterns.

RESULTS

LD in adolescence was positively associated with cardiometabolic risk in adulthood (b = 0.165, p < 0.001). LD also predicted lower educational attainment (b = -0.724, p < 0.001) and higher BMI (b = 0.589, p < 0.05). Educational attainment and BMI explained 18 and 25 percent of the positive association between LD and cardiometabolic risk, respectively. A moderated mediation model revealed that indirect effects of LD on cardiometabolic risk via educational attainment and BMI were more pronounced among women than men.

CONCLUSION

LD in adolescence is a significant predictor of cardiometabolic risk in adulthood. Interventions focusing on the academic and health behaviors of girls with LD may be effective in improving their adult physical health.

The mediating pathways between parental separation in childhood and offspring hypertension at midlife

Social life course determinants of adult hypertension are relatively unknown. This paper examines how parental separation before age 10 relates to hypertension at age 46. Adjusting for parental confounders and considering the role of adult mediators, we aim to quantify unexplored mediating pathways in childhood using prospectively collected data. Data from the 1970 British Birth Cohort Study are utilised. Hypertension is measured by health care professionals at age 46. Potential mediating pathways in childhood include body mass index (BMI), systolic and diastolic blood pressure, illness, disability, family socioeconomic status (SES) and cognitive and developmental indicators at age 10. Additionally, we explore to what extent childhood mediators operate through adult mediators, including health behaviours, family SES, BMI and mental wellbeing. We also test for effect modification of the relationship between parental separation and hypertension by gender. Nested logistic regression models test the significance of potential mediating variables. Formal mediation analysis utilising Karlson Holm and Breen (KHB) method quantify the direct and indirect effect of parental separation on offspring hypertension at midlife. There was an association between parental separation and hypertension in mid-life in women but not men. For women, family SES and cognitive and behavioural development indicators at age 10 partly mediate the relationship between parental separation and hypertension at age 46. When adult mediators including, health behaviours, family SES, BMI and mental wellbeing are included, the associations between the childhood predictors and adult hypertension are attenuated, suggesting that these childhood mediators in turn may work through adult mediators to affect the risk of hypertension in midlife. We found family SES in childhood, cognitive and behaviour development indicators at age 10, including disruptive behaviour, coordination and locus of control in childhood, to be important mediators of the relationship between parental separation and midlife hypertension suggesting that intervening in childhood may modify adult hypertension risk.

Associations Between Blood Pressure and Arterial Stiffness With Cognition: Neuroaggression or Neuroselection?

See Article by Lamballais et al.

Association of Early-Life Factors With Life-Course Trajectories of Resting Heart Rate: More Than 6 Decades of Follow-up

IMPORTANCE

Higher resting heart rate (RHR) is associated with increased risk of cardiovascular and all-cause mortality. Limited attention has been paid to early-life determinants of life-course RHR.

OBJECTIVE

To describe trajectories of RHR in the same individuals from age 6 to 69 years.

DESIGN, SETTING, AND PARTICIPANTS

Data were from the Medical Research Council National Survey of Health and Development population-based cohort of individuals who were followed up from birth in 1946 until 2015. Analysis was conducted between September 2016 and June 2017. Multilevel models were used to estimate life-course mean RHR trajectory by sex and to investigate associations with early childhood factors. The maximal sample included participants who had at least 1 measure of RHR since study entry and a measure of birth weight (N = 4779; observations = 26 182).

EXPOSURES

Information on early-life factors was ascertained prospectively: childhood socioeconomic position, birth weight, body mass index (calculated as weight in kilograms divided by height in meters squared) change from age 2 to 6 years (conditioned on body mass index at age 2 years), duration of breastfeeding, and markers of neurodevelopment (age at first walking independently and cognitive ability at age 8 years).

MAIN OUTCOMES AND MEASURES

Resting heart rate measured on 8 occasions between age 6 and 69 years (3 occasions in childhood and 5 in adulthood).

RESULTS

Of 4779 participants, 2492 (52.1%) were women, and 2287 (47.9%) were men. Mean estimated RHR decreased with increasing age and plateaued in adulthood. In sex-adjusted analyses, higher birth weight and conditional body mass index change were associated with lower RHR at age 6 years and across the life course (-0.56 bpm [95% CI, -0.95 to -0.17] per 1 kg higher birth weight and -0.30 bpm [95% CI, -0.48 to -0.13] per 1 kg/m2 change in body mass index). Associations between socioeconomic position and breastfeeding on RHR trajectory emerged in adulthood such that by age 69 years, RHR was 1.48 bpm (95% CI, 0.45 to 2.51) higher in participants from a disadvantaged vs advantaged background and -1.34 bpm (95% CI, -2.39 to -0.29) lower for those who were breastfed for 8 months or longer vs never. A later age at first walking was associated with higher RHR at age 6 years (1.49 bpm [95% CI, 0.39 to 2.59] higher for those 18 months or older vs those younger than 12 months) but with lower RHR in adulthood (-1.18 bpm [95% CI, -2.75 to 0.39] at age 69 years).

CONCLUSIONS AND RELEVANCE

Early life is a key period in determining future RHR trajectories with associations with potentially modifiable factors persisting into the seventh decade of life.

DO BIOMARKERS VARY BY SOCIAL CLASS, EDUCATION AND REGION AND IS MIGRATION IMPORTANT? EVIDENCE FROM A COHORT OF BRITISH ADULTS

The aim of this study was to test whether Body Mass Index (BMI), waist circumference, systolic and diastolic blood pressure, Forced Expiratory Volume (FEV1) and Peak Expiratory Flow (PEF) vary in relation to social class at birth and adulthood, educational level and region of residence, and also with inter-generational social, educational and regional mobility/migration. The study used 5702 adults (2894 males and 2718 females) from the longitudinal British National Child Development Study (all children born in England, Scotland and Wales during the first week in March 1958 with follow-up throughout childhood and adulthood, most recently at 55 years of age). In both sexes BMI and waist circumference tended to increase from social classes I+II to IV+V and higher social class was associated with higher mean FEV1 and PEF. Better-educated adults tended to have lower BMI and waist circumference, and higher mean FEV1 and PEF. Women from Wales had the highest mean BMI and waist circumference but the lowest mean PEF, while women in Scotland had the highest mean systolic blood pressure and the lowest mean FEV1. For men only, FEV1 and PEF showed regional variation and the lowest mean FEV1 was in Wales and the lowest PEF in Yorkshire & Humberside. Inter-generational social mobility was not found to be associated with any of the biomarkers, while educational mobility was related only to FEV1 and PEF. In both sexes, in unadjusted regression analysis regional migrant cohort members tended to have a lower mean BMI than sedentes. Regional male migrants also tended to have a lower waist circumference and a higher FEV1 and PEF than sedentes.

Updating the Evidence on the Association between Serum Cholesterol and Risk of Late-Life Dementia: Review and Meta-Analysis

BACKGROUND

Cohort studies have reported that midlife high total serum cholesterol (TC) is associated with increased risk of Alzheimer's disease (AD) in late-life but findings have been based on few studies and previous reviews have been limited by a lack of compatible data.

OBJECTIVE

We synthesized all high quality data from cohort studies reporting on the association between total serum cholesterol measured and late-life cognitive outcomes including Alzheimer's disease (AD), vascular dementia (VaD), any dementia, mild cognitive impairment (MCI), and cognitive decline.

METHODS

The literature was searched up to October 2016 using a registered protocol. Thirty-four articles meeting study criteria were identified. Seventeen studies published from 1996 to 2014, including 23,338 participants were included in meta-analyses.

RESULTS

Relative risk of developing AD for adults with high TC in midlife was 2.14 (95% CI 1.33-3.44) compared with normal cholesterol. Individual studies that could not be pooled also reported high TC in midlife increased the risk of MCI and cognitive decline in late-life. High TC in late-life was not associated with MCI, AD, VaD, any dementia, or cognitive decline. Late-life measured HDL cholesterol and triglycerides were not associated with increased risk of VaD, and HDL was not associated with risk of MCI, AD, or any dementia. There were insufficient data to examine other cholesterol sub-fractions, sex differences, or APOE interactions.

CONCLUSIONS

Significant gaps in the literature regarding TC and late-life dementia remain. Evidence suggests that high midlife TC increases risk of late-life AD, and may correlate with the onset of AD pathology.

Absence of Association between Behavior Problems in Childhood and Hypertension in Midlife

BACKGROUND

It is known that behavior in childhood is associated with certain physical and mental health problems in midlife. However, there is limited evidence on the role of childhood behavior problems in the development of hypertension in adulthood. The present study aimed to examine whether behavior problems in childhood influenced the risk of hypertension in midlife in the United Kingdom 1958 birth cohort.

METHODS

The 1958 British birth cohort comprised 17,638 individuals born in the first week of March 1958 in the United Kingdom. Behavior problems were assessed at 7, 11, and 16 years of age by parents and teachers. At age 45, blood pressure was measured and hypertension was recorded if blood pressure was ≥140/90 mm Hg or if the participants were informed by their health professionals that they had high blood pressure. Behavioral information was reported according to the Rutter Children's Behaviour Questionnaire (RCBQ) and the Bristol Social Adjustment Guide (BSAG). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine behavior problems in childhood in relation to hypertension at 45 years of age according to logistic regression analysis, with adjustment for sex, social class in childhood and adulthood, childhood cognition, birth weight, gestational age at birth, body mass index (BMI), smoking, alcohol consumption, and physical activity.

RESULTS

Behavior problems reported by parents at 7, 11, and 16 years were not associated with hypertension in midlife (OR, 0.93; 95% CI, 0.81, 1.07; OR, 0.95; 95% CI, 0.81, 1.11; OR, 0.98; 95% CI, 0.85, 1.12, respectively). Similarly, teacher-reported behavior problems at 7, 11, and 16 years were not associated with hypertension in midlife (OR, 0.92; 95% CI, 0.72, 1.18; OR, 0.92; 95% CI, 0.84, 1.02; OR, 1.03; 95% CI, 0.92, 1.15, respectively). Further separate analyses showed similar results for males and females.

CONCLUSION

There is no association between behavior problems in childhood and hypertension in midlife.

Is mid-life social participation associated with cognitive function at age 50? Results from the British National Child Development Study (NCDS)

Background

Some studies have indicated that social engagement is associated with better cognitive outcomes. This study aimed to investigate associations between life-course social engagement (civic participation) and cognitive status at age 50, adjusting for social networks and support, behavioural, health, social and socio-economic characteristics.

Methods

The vehicle for the study was the National Child Development Study (1958 Birth Cohort Study), which is a general population sample in England, Scotland and Wales (9119: 4497 men and 4622 women) participating in nationally representative, prospective birth cohort surveys. The primary outcome variable was cognitive status at age 50, measured by memory test (immediate and delayed word recall test) and executive functioning test (word fluency and letter cancelation tests). The influence of hypothesised predictor variables was analysed using linear multiple regression analysis.

Results

Cognitive ability at age 11 (β = 0.19;95% CI = 0.17 to 0.21), participation in civic activities at ages 33 (0.12; 0.02 to 0.22) and 50 (0.13; 0.07 to 0.20), frequent engagement in physical activity (sport) (β from 0.15 to 0.18), achieving higher level qualifications (β from 0.23 to 1.08), and female gender (β = 0.49;95% CI = 0.38 to 0.60) were positively, significantly and independently associated with cognitive status at age 50. Having low socio-economic status at ages 11 (β from -0.22 to -0.27) and 42 (β from -0.28 to -0.38), and manifesting worse mental well-being at age 42 (β = -0.18; 95% CI = -0.33 to -0.02) were inversely associated with cognitive status at age 50. The proportion of explained variance in the multiple regression model (18%), while modest, is impressive given the multi-faceted causal nature of cognitive status.

Conclusions

The results indicate that modest associations between adult social engagement and cognitive function at age 50 persist after adjusting for covariates which included health, socio-economic status and gender, supporting theories of neuroplasticity. In addition to the continuing emphasis on physical activity, the encouragement of civic participation, at least as early as mid-life, should be a targeted policy to potentially promote and protect cognitive function in later mid-life.

Electronic supplementary material

The online version of this article (doi:10.1186/s40359-016-0164-x) contains supplementary material, which is available to authorized users.

Associations Between Childhood Cognition and Cardiovascular Events in Adulthood: A Systematic Review and Meta-analysis

BACKGROUND

The success of behavioural interventions to optimize cardiovascular health is dependent on adequate cognitive functioning beginning in early life. In this study we aimed to systematically review studies that examined associations between childhood cognition and cardiovascular disease (CVD) events in adulthood.

METHODS

This study followed the Meta-analysis Of Observational Studies in Epidemiology guidelines to systematically examine associations between childhood cognition and adult CVD, coronary heart disease, and stroke hospitalization or mortality events. Literature was retrieved from EMBASE, MEDLINE, PsycInfo, and CINAHL.

RESULTS

Five longitudinal studies that examined links between childhood cognition and CVD in adulthood were included. Pooled estimates of unadjusted CVD events indicated a relative risk of 1.23 (95% confidence interval, 1.12-1.34) per standard deviation decrease in childhood IQ, whereas the pooled estimate adjusted for biopsychosocial confounding factors indicated an overall relative risk of 1.16 (95% confidence interval, 1.07-1.26).

CONCLUSIONS

Lower childhood IQ is associated with an increased risk of cardiovascular events in adulthood, even after adjustment for confounding variables. Future research should examine the behavioural mechanisms by which these risks are mediated to optimize cardiovascular health.

Metabolic syndrome in schizophrenia patients associated with poor premorbid school performance in early adolescence

OBJECTIVE

More than 40% of patients with schizophrenia have an additional diagnosis of the metabolic syndrome (MS), possibly related to poor cognition. This study investigated premorbid and current cognitive functioning in schizophrenia and co-occurrence of MS.

METHOD

A total of 104 participants with schizophrenia with MS and 142 without MS were included. Neuropsychological assessment was carried out using the Wechsler Adult Intelligence Scale-III, Word Learning Task, and Continuous Performance Test-HQ. Premorbid functioning was assessed retrospectively with the Premorbid Adjustment Scale. anovas were used to examine differences between participants with and without MS.

RESULTS

Subjects with and without MS did not differ concerning current, lifetime and amount substance use, duration/severity of illness, parental socioeconomic status (SES), and type/amount of antipsychotic medication. We found that poor school performance between the ages 12 and 16 is associated with MS in schizophrenia. Educational level and current cognitive functioning in participants with MS deviate as compared to those without MS.

CONCLUSION

Subjects with MS had impaired premorbid cognition in adolescence and lower educational achievement, irrespective of parental SES. This suggests poor premorbid cognitive functioning is a risk factor for metabolic complications later in life. Future studies are needed to examine whether cognitive interventions have beneficial effects on general health in schizophrenia.

Economic gradients in early child neurodevelopment: a multi-country study

Little is known about the importance of household wealth for child neurodevelopment very early in life including during infancy. Previous studies have focused on specific developmental domains instead of more holistic multi-domain measures of neurodevelopment and on economic effects for the "average" child instead of evaluating the heterogeneity in economic gradients by different levels of developmental ability. Furthermore, not much is known about whether economic gradients in early child neurodevelopment are country-specific or generalizable between populations. We evaluate wealth gradients in child neurodevelopment, an important predictor of future health and human capital, between ages 3 and 24 months in four South American countries. We also assess the heterogeneity in these gradients at different locations of the neurodevelopment distribution using quantile regression. Employing a unique dataset of 2032 children with neurodevelopment measures obtained by physicians in 2005-2006, we find a large positive wealth gradient in neurodevelopment in Brazil. The wealth gradient is larger for children at higher neurodevelopment rankings, suggesting that wealth is associated with child development inequalities in the form of a wider gap between low and high achievers on neurodevelopment in Brazil. This result highlights the need to target poverty in Brazil as a key factor in health and human capital disparities earlier in life rather than later as early developmental deficits will be carried forward and possibly multiplied later in life. More importantly, small or insignificant wealth gradients are generally found in the other countries. These results suggest that wealth gradients in child neurodevelopment are country-specific and vary with population demographic, health, and socioeconomic characteristics. Therefore, findings from previous studies based on specific populations may not be generalizable to other countries. Furthermore, wealth gradients in child neurodevelopment appear to be dynamic rather than fixed and sensitive to population characteristics that modify their intensity.

Dementia and Alzheimer's disease: a new direction.The 2010 Jay L. Foster Memorial Lecture

BACKGROUND

The modern era of Alzheimer's disease (AD) research began in the early 1980s with the establishment of AD research centers and expanded research programs at the National Institute on Aging.

METHODS

Over the past 30 years, there has been success in defining criteria for AD and dementia, association of important genetic disorders related to premature dementia in families, the association of apolipoprotein-E(4), and measurement of incidence and prevalence and selected risk factors. However, prevention and treatment have been elusive.

RESULTS

The development of new technologies, especially magnetic resonance imaging, positron emission tomography to measure amyloid in vivo in the brain and glucose metabolism, cerebrospinal fluid examination, better genetic markers, large-scale longitudinal epidemiology studies, and preventive clinical trials has rapidly begun a new era of research that offers opportunities to better understand etiology, that is, determinants of amyloid biology in the brain, neurofibrillary tangles, synaptic loss, and dementia.

CONCLUSIONS

There are three major hypotheses related to dementia: amyloid deposition and secondary synaptic loss as a unique disease, vascular injury, and "aging." New research must be hypothesis-driven and lead to testable approaches for treatment and prevention.

The association between childhood cognitive ability and adult long-term sickness absence in three British birth cohorts: a cohort study

OBJECTIVES

The authors aimed to test the relationship between childhood cognitive function and long-term sick leave in adult life and whether any relationship was mediated by educational attainment, adult social class or adult mental ill-health.

DESIGN

Cohort study.

SETTING

The authors used data from the 1946, 1958 and 1970 British birth cohorts. Initial study populations included all live births in 1 week in that year. Follow-up arrangements have differed between the cohorts.

PARTICIPANTS

The authors included only those alive, living in the UK and not permanent refusals at the time of the outcome. The authors further restricted analyses to those in employment, full-time education or caring for a family in the sweep immediately prior to the outcome. 2894 (1946), 15 053 (1958) and 14 713 (1970) cohort members were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

receipt of health-related benefits (eg, incapacity benefit) in 2000 and 2004 for the 1958 and 1970 cohorts, respectively, and individuals identified as 'permanently sick or disabled' in 1999 for 1946 cohort.

RESULTS

After adjusting for sex and parental social class, better cognitive function at age 10/11 was associated with reduced odds of being long-term sick (1946: 0.70 (0.56 to 0.86), p=0.001; 1958: 0.69 (0.61 to 0.77), p<0.001; 1970: 0.80 (0.66 to 0.97), p=0.003). Educational attainment appeared to partly mediate the associations in all cohorts; adult social class appeared to have a mediating role in the 1946 cohort.

CONCLUSIONS

Long-term sick leave is a complex outcome with many risk factors beyond health. Cognitive abilities might impact on the way individuals are able to develop strategies to maintain their employment or rapidly find new employment when faced with a range of difficulties. Education should form part of the policy response to long-term sick leave such that young people are better equipped with skills needed in a flexible labour market.

Intelligence

Individual differences in human intelligence are of interest to a wide range of psychologists and to many people outside the discipline. This overview of contributions to intelligence research covers the first decade of the twenty-first century. There is a survey of some of the major books that appeared since 2000, at different levels of expertise and from different points of view. Contributions to the phenotype of intelligence differences are discussed, as well as some contributions to causes and consequences of intelligence differences. The major causal issues covered concern the environment and genetics, and how intelligence differences are being mapped to brain differences. The major outcomes discussed are health, education, and socioeconomic status. Aging and intelligence are discussed, as are sex differences in intelligence and whether twins and singletons differ in intelligence. More generally, the degree to which intelligence has become a part of broader research in neuroscience, health, and social science is discussed.

Association between attention-deficit/hyperactivity disorder symptoms and obesity and hypertension in early adulthood: a population-based study

Objective

To examine associations between attention-deficit/hyperactivity disorder (ADHD) symptoms, obesity and hypertension in young adults in a large population-based cohort.

Design, Setting, and Participants

The study population consisted of 15,197 respondents from the National Longitudinal Study of Adolescent Health, a nationally representative sample of adolescents followed from 1995 – 2009 in the United States. Multinomial logistic and logistic models examined the odds of overweight, obesity, and hypertension in adulthood in relation to retrospectively reported ADHD symptoms. Latent curve modeling was used to assess the association between symptoms and naturally occurring changes in body mass index (BMI) from adolescence to adulthood.

Results

Linear association was identified between the number of inattentive (IN) and hyperactive/impulsive (HI) symptoms and waist-circumference, BMI, diastolic blood pressure, and systolic blood pressure (all ps for trend < .05). Controlling for demographic variables, physical activity, alcohol use, smoking, and depressive symptoms, those with 3 or more HI or IN symptoms had the highest odds of obesity (HI 3+ OR, 1.50; 95% CI, 1.22-2.83; IN 3+ OR, 1.21; 95% CI, 1.02-1.44) compared to those with no HI or IN symptoms. HI symptoms at the 3+ level were significantly associated with a higher OR of hypertension (HI 3+ OR, 1.24; 95% CI 1.01-1.51; HI continuous OR, 1.04; 95% CI 1.00-1.09), but associations were non-significant when models were adjusted for BMI. Latent growth modeling results indicated that compared to those reporting no HI or IN symptoms, those reporting more 3 or symptoms had higher initial levels of BMI during adolescence. Only HI symptoms were associated with change in BMI.

Conclusion

Self-reported ADHD symptoms were associated with adult BMI and change in BMI from adolescence to adulthood, providing further evidence of a link between ADHD symptoms and obesity.