We use epidemiological, mechanistic and clinical studies to understand lifecourse influences on sarcopenia and frailty in older age, and to evaluate preventive opportunities.

A series of observational epidemiological studies have linked low birth weight with reduced muscle strength in later life (see figure). This association was first reported in the Hertfordshire Ageing Study (HAS), a retrospective birth cohort study of men and women born in Hertfordshire (1920-30).283 3HAS together with the Hertfordshire Cohort Study (HCS)635 4 have been central to our development of a lifecourse approach to sarcopenia and frailty, both as individual studies and as part of the Healthy Ageing across the Lifecourse (HALCyon) consortium of UK birth and ageing cohorts.309 5,728 6 HAS and HCS continue to be key cohorts in our epidemiological studies.

The associations between early size and grip strength remain after taking account of adult height, suggesting that an adverse early environment may have an effect on both muscle quality and quantity. These findings have led to the Hertfordshire Sarcopenia Study (HSS), that aims to investigate the cellular and molecular mechanisms underlying the association between birth weight and subsequent muscle mass and strength.213 7

We are also using data from other UK cohorts to identify social and psychological factors from across the lifecourse that increase or reduce older people’s risk of becoming frail.   People who are from a more disadvantaged socioeconomic position in adult life are more likely to become frail, but little is known about the effect of socioeconomic deprivation in childhood. Having a lower sense of mental wellbeing in adult life is linked with a higher risk of becoming frail. We now need to understand the biological and behavioural mechanisms by which wellbeing might influence frailty risk, and to explore whether other psychological or social factors such as personality, attitudes to ageing or social engagement play a part in this relationship between happiness and the development of frailty. We also want to discover which characteristics of frail older people increase or reduce their risk of poor outcomes, such as falls or earlier death.

An important part of ongoing research is to determine how our findings can be translated into health improvements, through community interventions as well as changes in the clinical care of older people. Central to these aims are activities to prevent sarcopenia and frailty, as well as the implementation of diagnosis in routine clinical practice.

Our epidemiological, mechanistic and clinical studies are supported by strong links with a number of external organisations, including the NIHR Southampton Biomedical Research Centre.