Association between serum uric acid and muscle strength in older adults with or without gout diagnosis: NHANES 2011-2014.

Background & Aims: Increased oxidative stress seems to be one of the causes of muscle strength loss during aging. Uric acid (UA) is an important antioxidant that has been positively associated with muscle strength in older adults. However, UA is also a prerequisite for gout, which is a type of arthritis that increases inflammation. The association between UA and muscle strength in individuals with gout is unknown. The aim of the study was to associate muscle strength with UA in older adults with or without gout diagnosis.

Methods: The present study evaluated older adults aged from 60 to 80 years from National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014. A total of 2529 individuals (1249 men and 1280 women) were evaluated, with (n = 201) or without (n = 2328) gout diagnosis. Muscle strength was measured using a handgrip dynamometer. The combined grip strength (sum of highest values of both hands) was evaluated. Linear regression analysis was performed to evaluate the association between UA and strength adjusting for confounders.

Results: Evaluating the individuals without gout, UA was positively associated with muscle strength [(β = 0.66 (CI = 0.08; 1.24); p = 0.028)]. However, this association was not significant in individuals with gout [(β = 0.20 (CI =  - 1.18; 1.58); p = 0.774)].

Conclusion: Serum UA is positively associated with handgrip strength only in older adults without gout diagnosis. These results suggest that the presence of gout may avoid a positive association between UA and muscle strength in older adults.