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.