Early life factors and grip strength at older ages in two distinct populations in China and England

BACKGROUND: Early life factors are associated with poor physical and mental outcomes in late life. However how these are associated with grip strength, an objective measure of physical capacity and therefore morbidity and mortality in late life unclear. This analysis therefor explores the long-term effects of adverse childhood socioeconomic experiences and health on grip strength in late life, and how these are mediated by adult factors. METHODS: Data on early life events, health and socioeconomic factors and grip strength were collected from the China Health and Retirement Longitudinal Study (CHARLS) and English Longitudinal Study of Ageing (ELSA). Participants’ first entry into the survey from waves 1-3 in CHARLS and waves 1-9 in ELSA were included in the analysis. Sex stratified linear regression models were used to explore how early life factors affect grip strength. Childhood events included parental socioeconomic position and childhood health. RESULTS: 17,205 participants from CHARLS and 6,692 participants from ELSA were included in this analysis. Unlike ELSA, participants from CHARLS were younger, had lower education, low-income occupation and obese. Low parental education and poor child health perception were negatively associated with grip strength even after controlling for childhood and adult factors (adult socioeconomic position, adult body size, adult health and lifestyle) in men from both studies. While parental occupation was associated with grip strength for both males and females in both studies. Association of SEP and health in childhood with grip strengths at older ages were however explained by body size and adult health factors, and not adult SEP. KEY MESSAGES: • Early life socioeconomic position has a persistent effect of late physical health, even after considering adult health, socioeconomic position and lifestyle. • Early intervention in socioeconomic inequalities might improve health outcomes across the life course.