Higher Grip Strength Is Associated With Reduced Risk of Incident Symptomatic Hand Osteoarthritis: Data From Two Cohort Studies.

BACKGROUND

Grip strength is increasingly recognized as a modifiable and easily measurable protective factor against chronic diseases. Lower grip strength may compromise joint stability, predisposing periarticular tissues to local inflammation, which has been implicated in hand osteoarthritis (HOA), a condition affecting approximately 189 million people globally and imposing substantial health and socio-economic burden. Whether lower grip strength is a risk factor for clinically relevant symptomatic HOA remains unclear. We aimed to examine the association between grip strength and incident symptomatic HOA to inform targeted preventive strategies.

METHODS

We conducted prospective cohort studies and Mendelian randomization analyses using data from the Xiangya Osteoarthritis (XO) Study and UK Biobank. Individuals without baseline symptomatic or hospital-diagnosed HOA were included. Genetic instruments for grip strength were derived from genome-wide association studies. Symptomatic HOA in the XO Study was defined as the presence of radiographic HOA with symptoms, whereas hospital-diagnosed HOA in the UK Biobank was ascertained through hospital inpatient records.

RESULTS

Among 2869 XO Study participants (5461 hands; 55.9% women; mean age of 63.2 years), 166 (3.0%) hands developed incident symptomatic HOA during a mean follow-up of 3.7 years. Compared with the lowest grip strength quartile, odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) of symptomatic HOA in the second, third and highest quartiles were 0.51 (95% CI, 0.31-0.84), 0.62 (95% CI, 0.39-0.99) and 0.46 (95% CI, 0.28-0.75), respectively (p for trend = 0.003). Similar associations were observed among 481 582 UK Biobank individuals (54.2% women; mean age of 56.4 years). Mendelian randomization analyses showed ORs of genetically determined grip strength of 0.56 (95% CI, 0.40-0.78, p < 0.001) for incident symptomatic HOA in the XO Study and 0.37 (95% CI, 0.25-0.56, p < 0.001) for incident hospital-diagnosed HOA in the UK Biobank.

CONCLUSIONS

Higher grip strength was associated with a lower risk of incident symptomatic HOA. These findings offer empirical evidence that interventions aimed at enhancing grip strength may help prevent symptomatic HOA and reduce its individual and societal burden.