Handgrip strength predicts longitudinal changes in clock drawing test performance. An observational study in a sample of older non-demented adults

Objective Impairment of physical performance might identify older people at higher risk of dementia over time. The present study evaluated handgrip strength as independent predictor of cognitive decline. Design Observational, prospective. Follow-up duration: 11.2 ± 0.8 months. Setting and participants Geriatric outpatients center. 104 consecutive stroke- and dementia-free older adults (44% men, ages 80.2±5.4 years). Methods The Clinical Dementia Rating scale and the Clock Drawing Test (CDT) were administered. Handgrip strength was assessed using a Jamar hand dynamometer. Brain magnetic resonance imaging studies at 1.5 T were performed. White matter damage was expressed as severity of white matter hyperintensities (WMHs). Longitudinal changes in cognitive function were expressed as 1-year decline in CDT performance. Results A robust association was observed between baseline handgrip strength and 1-year cognitive decline after multiple adjustment. Of note, the strength of such association was only minimally attenuated after adjusting for deep WMHs extent (β coefficient for handgrip strength = 0.183, SE= 0.038, p= 0.007, R2= 0.58). Conclusions Handgrip strength predicted accelerated 1-year decline in cognitive function, assessed by CDT, in a sample of older adults. Future studies are needed to elucidate the causal mechanisms linking limitations in physical function with dementia risk.