by Kate Birnie, Rachel Cooper, Richard M. Martin, Diana Kuh, Avan Aihie Sayer, Beatriz E. Alvarado, Antony Bayer, Kaare Christensen, Sung-il Cho, Cyrus Cooper, Janie Corley, Leone Craig, Ian J. Deary, Panayotes Demakakos, Shah Ebrahim, John Gallacher, Alan J. Gow, David Gunnell, Steven Haas, Tomas Hemmingsson, Hazel Inskip, Soong-nang Jang, Kenya Noronha, Merete Osler, Alberto Palloni, Finn Rasmussen, Brigitte Santos-Eggimann, Jacques Spagnoli, John Starr, Andrew Steptoe, Holly Syddall, Per Tynelius, David Weir, Lawrence J. Whalley, Maria Victoria Zunzunegui, Yoav Ben-Shlomo, Rebecca Hardy, on behalf of the HALCyon study team
Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood. Methods and Findings
Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N?=?17,215 for chair rise time to N?=?1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations. Conclusions
Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.