Is grip strength a useful single marker of frailty?

Background: chronological age is widely used as a marker of frailty in clinical practice. However there can be wide variation in frailty between individuals of a similar age. Grip strength is a powerful predictor of disability, morbidity and mortality which has been used in a number of frailty scores but not as a single marker of frailty. Objective: to investigate the potential of grip strength as a single marker of frailty in older people of similar chronological age. Design: cross-sectional study with prospective collection of mortality data. Setting: North Hertfordshire, UK. Subjects: 717 men and women, aged 64-74, born and still living in North Hertfordshire, who took part in a previous study to investigate the relationship between size at birth and ageing processes in later life. Methods: the number of significant associations between grip strength and the ageing markers was compared with numbers between chronological age and the ageing markers. Results: in men, lower grip strength correlated significantly with ten ageing markers compared to chronological age which was significantly associated with seven. In women, there were six significant relationships for grip compared to three for age. The greater number of relationships between grip strength and ageing markers was not explained by the association between grip strength and age, and remained after adjustment for adult size. Conclusions: grip strength was associated with more markers of frailty than chronological age within the narrow age range studied. Grip strength may prove a more useful single market of frailty for older people of similar age than chronological age alone. Its validity in a clinical setting needs to be tested.