OP09 Childhood cognitive ability and standing balance in mid to later life: findings from the mrc national survey of health and development

Background Physical performance indicators, such as standing balance, grip strength and walking speed, are increasingly being used as markers of healthy ageing. This is based on growing evidence that poor performance on these tests is associated with adverse health outcomes including falls, disability, hospitalisation and mortality. Individual variation in the levels of performance on each of these tests may be due to diverse contributing factors across life. Previous research has suggested that neurodevelopmental pathways may be particularly important for balance performance; however the few published studies on this have only examined balance at one age. We aimed to examine the associations between childhood cognitive ability, a marker of neurodevelopment, and standing balance at three ages in mid and later life. Methods Up to 2785 participants from the MRC National Survey of Health and Development, a British cohort study followed since birth in 1946, were included in analyses. Standing balance was assessed at ages 53, 60–64 and 69 using the one-legged stand test with eyes closed up to a maximum of 30 s. Childhood cognitive ability was assessed using a set of standardised tests at age 15. Linear regression models estimated the association between childhood cognitive ability and log-transformed balance at each age. Adjustments were made for sex, childhood socioeconomic position, current physical activity, height and weight. Analyses were performed using STATA v14.1. Results Men had better median balance times than women at age 53 [Men: 5 (interquartile range: 3–10); Women: 4 (3–7)], 60–64 [M: 3.7 (2.5–5.6); W: 3.3 (2.3–4.8)], and 69 [M: 3.0 (2.0–5.0); W: 2.9 (1.9–4.3)], but a decline in median balance times with age was observed in both sexes. In sex-adjusted and fully-adjusted models, higher childhood cognitive ability was associated with better balance times, although this association weakened with increasing age. A one standard deviation increase in childhood cognitive ability was associated with fully-adjusted mean differences in log-balance times (ln(s)) of 0.12 (95% CI: 0.08–0.15), 0.05 (95% CI: 0.02–0.09) and 0.04 (95% CI: 0.001–0.08) at ages 53, 60–64 and 69, respectively. Conclusion Balance performance decreased with age, and was consistently lower in women than men. Higher childhood cognitive ability was associated with better balance performance at all ages but the strength of this association weakened over time. Further research should examine how the associations of other neurodevelopmental factors with balance change with age. Interventions earlier in life may help to maintain balance performance from midlife.