Association of physical activity and balance ability with disability:a cross-sectional study based on NHANES
HAN Xuejiao
SHI Jipeng
WEI Jinpeng
ZHU Tianrui
XU Hongqi
HE Muhan
Abstract：Objective To investigate the association of physical activity and balance ability with disability,and to further examine the mediating role of balance ability in the relationship between physical activity and disability.
Methods Based on data from 2021 to 2023 National Health and Nutrition Examination Survey(NHANES)cycle,a mul-tivariable Logistic regression model was constructed to evaluate the independent association of physical activity and balance ability with disability,with covariates adjusted in four steps.An interaction model was further devel-oped to assess the multiplicative interaction between physical activity and balance ability.Mediation analysis was performed using the Baron and Kenny three-step approach to examine the mediating role of balance ability,and the proportion of the mediation effect was calculated.The significance of the mediation effect was assessed using the Delta method,and robustness was verified through the Bootstrap method with a fixed random seed.Multiple sensitivity analyses were conducted to ensure the stability of the results.
Results A total of 3 902 participants were included,with a prevalence of disability of 17.7%.Multivariable regression analysis showed that,after adjusting for all covariates,both light-intensity physical activity(LIPA)(OR=0.489,95%CI 0.380 to 0.629,P<0.001)and high-intensity physical activity(HIPA)(OR=0.493,95%CI 0.371 to 0.656,P<0.001)were significantly associated with a reduced risk of disability,whereas impaired balance ability was significantly associated with an increased risk(OR=1.579,95%CI 1.266 to 1.970,P<0.001).The interac-tion effect analysis showed that the interaction between physical activity and balance ability were not significant(P>0.05),however,the main effect of LIPA remained robust(β=-0.597,SE=0.221,OR=0.550,P=0.007),while impaired balance ability was significantly associated with an increased risk of disability(β=0.577,SE=0.231,OR=1.780,P=0.012).The mediation analysis further indicated that balance ability played a robust medi-ating role in the association between LIPA and disability,with a mediation proportion of 21.1%.The indirect ef-fect(a×b)was statistically significant(P<0.001),and the 95%confidence intervals derived from the bootstrap method did not include zero.
Conclusion Physical activity and balance ability are significantly associated with disability,and balance ability may me-diate the relationship between physical activity and disability,highlighting its potential value in disability risk as-sessment and intervention strategies.
Keywords：physical activitybalance abilitydisabilityNational Health and Nutrition Examination Surveymediation effect
Publication Date：2026-01-25
Online Publishing Date：2026-02-04(First online date of this platform, not the publication date of the document)
Pages：12( 1-12 )