Handgrip Strength-Related Factors Affecting Health Outcomes in Young Adults: Association with Cardiorespiratory Fitness

OBJECTIVES: Handgrip strength (HS) is a risk factor of all-cause mortality and cardiovascular diseases. However, the influencing factors and mechanisms contributing to this correlation remain unclear. Therefore, we aimed to explore factors related to HS and investigated the mechanism underlying its risk predictive value. METHODS: This was a prospective, cross-sectional study. One hundred forty-five participants were recruited from December 2019 to November 2020. HS was measured using a hydraulic hand dynamometer and adjusted for body mass index (HS(BMI)) and body surface area (HS(BSA)). Body composition was assessed via bioimpedance spectroscopy. Physical fitness was measured using a cardiopulmonary exercise test system. Univariate, multiple linear regression analyses and receiver operator characteristic curve (ROC) were conducted to evaluate the associations between various participant characteristics and HS. RESULTS: The average participant age was 21.68 ± 2.61 years (42.8% were male). We found positive correlations between HS(BMI)/HS(BSA) and VO(2max), VE(max), Load(max), and MET(max) in both sexes (p < 0.05). Lean-tissue, protein, total water, and inorganic salt percentages were positively correlated, and fat percentage was negatively correlated with HS(BMI) in men and with HS(BMI) and HS(BSA) in women (p < 0.05). Multiple regression revealed that VO(2max) was independently associated with HS(BSA) in both sexes (β = 0.215, 0.173; 95%confidence interval [CI] = 0.032 − 0.398, 0.026-0.321; p = 0.022, 0.022, respectively) and independently associated with HS(BMI) in women (β = 0.016, 95%CI = 0.004 − 0.029, p = 0.011). ROC analysis showed that HS(BMI) and HS(BSA) can moderately identify normal VO(2max) in men (area under curve [AUC] = 0.754, 0.769; p = 0.002, 0.001, respectively) and marginally identify normal VO(2max) in women (AUC = 0.643, 0.635; p = 0.029, 0.042, respectively). CONCLUSIONS: BMI- and BSA-adjusted HS could serve as indicators of physical health, and HS(BSA) may moderately reflect cardiorespiratory fitness levels in healthy young adults, particularly in males. Clinical trials registry site and number: China Clinical Trial Center (ChiCTR1900028228).