Association between handgrip strength and lung function indices in the UK Biobank.

<bold>Background:</bold> While findings from pulmonary rehabilitation programs and clinical cohorts have highlighted positive health effects of physical fitness in lung disease, there is little evidence on the association of physical fitness, including handgrip strength, with lung function among lung-healthy individuals. <bold>Objective:</bold> Therefore, this study investigated the association between physical fitness measured by handgrip strength with spirometric parameters. <bold>Methods:</bold> This research has been conducted using the UK Biobank Resource. Handgrip strength measurements and lung function testing by spirometry were performed during the baseline assessment. After exclusion of participants with lung diseases, handgrip strength and valid spirometry were available for 193,501 adults aged 39-72 years. Associations between mean values of handgrip strength and spirometric parameters were analyzed using linear regression models adjusted for confounding factors and stratified by sex. <bold>Results:</bold> Handgrip strength was significantly associated with lung function parameters. Forced vital capacity (FVC) increased by 12.4 ml (95% CI 11.9-12.9) in both males and females whereas forced expiratory volume in 1 second (FEV1) increased by 9.7 ml (95% CI 9.2-10.1) in males and 10.0 ml (95% CI 9.6-10.4) in females per 1 kg increase in handgrip strength. FEV1/FVC and peak expiratory flow also showed a direct association with handgrip strength. Effect modification by smoking status could be observed among males with smaller effects for former and current smokers compared to never smokers. <bold>Conclusion:</bold> Muscle strength, measured by handgrip strength, is positively associated with lung function parameters in adults without lung diseases.