The relationship between pulmonary function, and hand grip strength among young adults: a cross-sectional study

Pulmonary function and skeletal muscle strength are key indicators of physiological health, yet evidence describing their relationship in young, healthy populations remains underexplored in Saudi Arabia. This study aimed to examine the association between pulmonary function and handgrip strength (HGS) in healthy young adults while controlling demographic, anthropometric and lifestyle factors.

In this cross-sectional study, 71 healthy young adults (18-25 years) were recruited from the central region of Saudi Arabia. Pulmonary function test (PFT) was assessed using spirometry, including forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), FEV₁/FVC ratio, and peak expiratory flow (PEF). HGS was measured using a Jamar dynamometer. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). Unadjusted associations were examined using Spearman's correlation coefficients. Hierarchical multiple linear regression was performed to evaluate the independent association between pulmonary function parameters and HGS, adjusting for age, sex, height, weight, physical activity, and smoking status.

Unadjusted analyses showed moderate positive correlations between HGS and absolute spirometry indices, including FVC (r = 0.53), FEV₁ (r = 0.54), and PEF (r = 0.53; all p < 0.001). Associations with percentage-predicted spirometry values were weak and nonsignificant. In hierarchical multiple linear regression analysis, age, sex, height, weight, physical activity, and smoking status explained 34.3% of the variance in HGS (p < 0.001). After adjustment for these covariates, the addition of FVC (ΔR² = 0.003, p = 0.597), FEV₁ (ΔR² = 0.019, p = 0.203), and PEF (ΔR² = 0.002, p = 0.702) did not significantly improve model fit. The final model explained 36.7% of the variance in HGS.

Pulmonary function was positively associated with HGS in unadjusted analyses; however, this association was attenuated after adjustment for demographic, anthropometric, and lifestyle factors. These findings suggest that factors, such as sex and body size, may partially account for the association between pulmonary function and HGS in healthy young adults.