Association of handgrip strength and walking pace with incident Parkinson's disease

We aimed to quantify the association of handgrip strength and self-reported walking pace with incident Parkinson's disease (PD) in the general population.

A total of 419 572 participants (54.1% females, mean age: 56.1 years [SD, 8.2]) without prior PD were included from UK Biobank. Handgrip strength was assessed by dynamometer. Walking pace was self-reported as slow, average or brisk. The study outcome was incident PD, determined by self-report data, hospital admission records or death records.

The mean handgrip strength was 23.5 (SD, 6.3) and 39.6 (SD, 8.9) kg for females and males, respectively. A total of 33 645 (8.0%), 221 682 (52.8%) and 164 245 (39.2%) participants reported slow, average and brisk walking pace, respectively. Over a median follow-up duration of 12.5 years, 2152 participants developed incident PD. When handgrip strength was assessed as sex-specific tertiles, compared with those in the third tertile, the adjusted hazard ratios (HRs) (95% confidence interval [CI]) of incident PD for participants in the second and first tertiles were 1.23 (1.09-1.39) and 1.60 (1.42-1.79), respectively. Compared with brisk walking pace, average (HR, 1.33; 95% CI: 1.20-1.47) or slow (HR, 1.84; 95% CI: 1.57-2.15) walking pace was associated with a higher risk of incident PD. A lower grip strength (Tertiles 1 and 2) and an average/slow walking pace accounted for 23.8% and 19.9% of PD cases, respectively. When handgrip strength and walking pace were considered together, the highest risk of incident PD was observed in participants with both lowest handgrip strength and slow walking pace (HR, 2.89; 95% CI: 2.30-3.64). Genetic risks of PD did not significantly modify the relation of handgrip strength (P for interaction = 0.371) or walking pace (P for interaction = 0.082) with new-onset PD.

Low handgrip strength and slow walking pace were significantly associated with a higher risk of incident PD, regardless of the individuals' genetic risk profile.