INTRODUCTION: The relationships between grip strength asymmetry and cardiovascular, respiratory, and cancer outcomes and all-cause mortality remain unclear. METHODS: Among 443,132 UK Biobank participants enrolled from 2006 to 2010, grip strength asymmetry was defined as the ratio of left-hand grip strength (kg) to right-hand grip strength (kg) <
0.9 or >
1.1. The Cox proportional model was employed to assess the associations of grip strength asymmetry with cardiovascular, respiratory, and cancer outcomes and all-cause mortality. Net reclassification improvement was assessed to evaluate the improvement in risk discrimination for outcomes after adding grip strength asymmetry to the model with established office-based risk factors. RESULTS: After a mean follow-up of 12.1 years, 28,478 (6.4%) deaths occurred. grip strength asymmetry was significantly associated with all-cause (hazard ratio: 1.096
95% CI=1.070, 1.122), cardiovascular disease (hazard ratio: 1.141
95% CI=1.071, 1.216), respiratory disease (hazard ratio: 1.183
95% CI=1.076, 1.301), chronic obstructive pulmonary disease (hazard ratio: 1.284
95% CI=1.087, 1.516), and cancer (hazard ratio: 1.051
95% CI=1.017, 1.086) mortality. Significant associations of grip strength asymmetry with cardiovascular disease (hazard ratio: 1.029
95% CI=1.004, 1.054), respiratory disease (hazard ratio: 1.074
95% CI=1.051, 1.103), chronic obstructive pulmonary disease (hazard ratio: 1.123
95% CI=1.038, 1.215), and colorectal cancer (hazard ratio: 1.051
95% CI=1.037, 1.066) incidence were observed. Moreover, adding grip strength asymmetry to a model with established office-based risk factors significantly improved the ability to predict all-cause, cardiovascular disease, and respiratory disease mortality. CONCLUSIONS: Grip strength asymmetry was associated with a range of adverse health outcomes and may have clinical use in predicting all-cause, cardiovascular disease, and respiratory disease mortalities. Further studies are warranted to validate the clinical value of the grip strength asymmetry assessment.