Biomedical follow-up of 1958 Birth Cohort Study members at age 60

The increase in human life expectancy over the last century has been one of the greatest achievements in public health. However, it also poses new challenges in health and social care, in particular the increased burden of ill health associated with older age, including cognitive impairment and frailty. Understanding the occurrence of these ageing outcomes and their determinants has become a global research priority with considerable policy implications. Several influential studies have been established in middle- and older-aged populations in the UK and in other countries with the capacity to offer much-needed insights into these issues. It has recently become evident, however, that the processes that underlie ageing states begin much sooner in the life course than originally thought, in some cases as early as birth or preconception.
It is in such studies that cover the lifespan that the UK excels. The 1958 Birth Cohort Study in the UK is the largest long-running study of this type. Its study members are approaching 60 years of age, when problems of ageing typically begin to emerge. We will therefore carry out a detailed survey which captures key domains of healthy ageing incorporating multiple dimensions of health (for example, cardiometabolic, cognitive, and physical health) combined with genetic and environmental factors that have been collected across the lifetime of the cohort. Uniquely, this new information will allow us to answer a series of important research questions of public health importance. These include the role of infection in early life in CVD, explaining why individuals remain undiagnosed or inadequately treated for CVD and diabetes, the extent to which CVD risk in early older age can be reversed by physical activity initiated in midlife, how physical function and co-ordination in childhood are related to physical function measures at age 60, and whether the duration and quality of employment over the lifetime is protective of cognitive decline. We will also be able to run a series cross-cohort comparisons, to allow us to highlight where such disease and ageing processes are changing across generations. These data will become publically available to scientists soon after collection, so providing an unparalleled resource for the scientific community to investigate a range of policy-relevant issues. This improved understanding will ultimately lead to changes in individual behaviour and improvements in public policy and professional practice that will lead to better public health and healthier longer lives.
In summary, what affects health and how fast we age was originally thought to be a result of what we did as adults, such as how much we smoked, drank, exercised, and our weight, as well as our genes. Research is now beginning to show that factors in our childhood may also have an impact on later illness and ageing. Financial help from the Medical Research Council will allow us to track the health of people who were born in the 1950s in the UK as they reach 60 years of age, to show how lifelong factors affect how we age, and to recommend policies that will improve the health of the older population.

This application proposes an ambitious programme of work to inform key public health concerns among generations now transitioning between midlife and early older age, a critical time when major chronic disease events and other health concerns of older age accumulate.
Our work conceptualizes healthy ageing within a life-course framework in which we investigate the socioeconomic, biological, and psychological determinants of healthy ageing over a lifetime and their contribution to transitions in health outcomes measured objectively from midlife (44/45 years) to early older age (60 years). Our approach incorporates multiple interrelated dimensions of health and encompasses flexibly the mechanisms through which such exposures operate. Within such a framework, a set of interrelated hypotheses are set out concerning cardiometabolic health, physical function, cognitive decline, and biological ageing.
These scientific aims will be achieved through a major biomedical enhancement of the 1958 Birth Cohort Study, through collection of data on 9,600 study members when they reach 60 years of age. Proposed domains of data for collection include physical measurements (height, weight, body-fat, waist and hip circumference); physical functioning (grip strength, balance, chair rises, gait speed); blood pressure, pulse rate; the effect of static and dynamic exercise on blood pressure; the collection and storage of whole bloods; cognitive assessments (memory, processing speed, executive function). Data will be deposited with the UK Data Service for the widest possible use by bona fide researchers after collection and data cleaning, under exemplary access arrangements, and alongside a strong communications campaign to raise awareness of the new data.

The benefits to the public of the proposed work will centre on identifying life-course factors that improve population health in the period between mid-forties and early older age (60), setting the course for healthy ageing trajectories thereafter. It will also enable a better understanding of how health has changed among a nationally representative sample of 60 year olds born in 1958 (in 2018) compared with those born in 1946 (in 2006). This in turn will inform the development of preventative health policies across the whole of life that will expand healthy life expectancy, and reduce the burden of ill health and disease at older ages.

The strongest impacts will relate to the major domains of the proposed data collection, covering cardiometabolic health, physical function, cognition, and biological ageing. Our work focuses both on identifying the early life risk factors for subsequent health, and on identifying whether such effects can be reversed. This will provide valuable information about which stages in the life course remediation of key risks for unhealthy ageing are possible, and ultimately enables the relative costs and benefits of prevention measures at different life stages to be assessed. For example, if it is found that early life conditions affect ageing risks in a largely irreversible way, this will demonstrate that preventive interventions are essential in early life, while where reversal of such risk is found to be possible later, then targeted remedial interventions might still be effective in promoting healthy ageing. One example of the potential benefit of our work is in cardiometabolic health, where current clinical practice is dominated by relatively short term risk perspectives (e.g., 10 year risk) which in effect favours late intervention, when irreversible damage may have already accrued. Our research will highlight the way in which the determinants of CVD/diabetes act over the life course, including in childhood (for example highlighting the potential benefits of influenza immunisation during pregnancy) and in adult life (focussing on polices to reduce dietary salt, and physical activity), thus providing vital information about the benefits of preventative strategies from birth and throughout life.

Intermediate beneficiaries will be policymakers such as those in the Department of Health, Public Health England, NHS Commissioning, Clinical Commissioning Groups, Health and Wellbeing Boards, and the Association of Directors of Public Health, as well as those in local government, who require evidence on where to invest vital resources (e.g., the relative benefit to investment in behaviour change at different life stages); third-sector campaigning agencies (representing the older population, patient groups); and medical practitioners.

The timing of the realisation of benefits is not known precisely since it relies on future funding of research based on the new data. Previous experience suggests a surge of initial papers in peer reviewed journals at three years from data collection, with the number of publications building strongly thereafter, and continuing to grow even after more than a decade. The benefits of the proposed data collection will be sustained over many years as they are used as a baseline against which health at older ages is judged.