Abstract
Low grip strength in later life, a marker of sarcopenia, is an established risk factor for subsequent disability, morbidity and mortality. The principal determinants of low grip strength have been established as: older age; shorter stature; low physical activity; poor nutrition; socioeconomic disadvantage and comorbidity. Little is known about risk factors for accelerated loss of grip strength in later life. We investigated determinants of level and loss of grip strength using data from 1650 men and 2053 women (aged 50 to 89 years), who had grip strength measured at waves 2, 4 and 6 of the English Longitudinal Study of Ageing. Loss of grip strength was characterised using a residual multilevel-modelling approach and analysed for men and women combined in relation to participant characteristics. Older age, shorter stature, physical inactivity and comorbidity were associated with lower level, and accelerated loss, of grip strength (p≤0.001 for all associations). Lower levels of physical activity, household wealth (p<0.001) and never having married (p=0.02) were all associated with lower level of grip strength, but not with rate of loss. Our data suggest that peak muscle strength and the rate of involutional muscle weakness contribute in approximately equivalent proportion to the muscle strength of older people (75–89 years). Our results further suggest that each of these components may have different determinants during growth and older age. Further research is required to replicate our results and to inform development of interventions to promote maintenance and prevent loss of muscle strength in later life.