Hand grip endurance test relates to clinical state and prognosis in COPD patients better than 6-minute walk test distance

Abstract

Purpose

Patients with COPD present peripheral muscle dysfunction and atrophy, expressed as muscle strength and endurance reduction. The goal of this study was direct dynamometric assessment of hand grip endurance and strength in relation to the stage of disease, multidimensional predictors of mortality, and 6-minute walk test (6MWT). To the best of our knowledge, there has been no previous study determining these parameters.

Patients and methods

In this observational study, 58 consecutive outpatients with stable COPD and 25 volunteers without respiratory problems were compared. All COPD subjects underwent a comprehensive examination to determine COPD severity, prognostic scales, and 6MWT. Body composition, basic spirometric parameters, and hand grip strength and endurance were determined in all study participants.

Results

Patients in the COPD group had a 15% decrease in maximum strength (P=0.012) and a 28% decrease in area under the force/time curve (AUC) of the endurance test (P<0.001) compared to the control group. Dynamometric parameters were significantly negatively associated with the stage of disease and values of multivariable prediction indexes, and positively associated with the results of 6MWT. In most cases, closer associations were found with AUC than with 6MWT and in the gender-specific groups.

Conclusion

Both hand grip strength and endurance are impaired in COPD patients in comparison with the control group. In particular, AUC could be considered as an attractive option not only to assess exercise capacity but also as a predictive marker with a better prognostic value than 6MWT in COPD patients. This is the first study to observe the dependence of hand grip endurance on combined COPD assessment.

Keywords:

• dynamometry
• muscle strength
• muscle endurance
• BODE index

Acknowledgments

This work was not supported by sponsors: the Faculty of Pharmacy (SVV/2017/260417), MH CZ – DRO (UHHK, 00179906), and PROGRES Q42 are gratefully acknowledged. The authors are grateful to Ian McColl MD, PhD, for assistance with preparation of the manuscript.

Author contributions

MK served as principal investigator, had full access to all of the data in the study, and takes responsibility for the integrity of the data and the accuracy of the data analysis; MK, VK, ZZ, and MH contributed to study design; MK, VJ, AP, VK, and MH contributed to data collection; MK, VJ, AP, VK, ZZ, and MH contributed to data analysis; MK contributed to statistical analysis; MK, VJ, AP, VK, ZZ, and MH contributed to the writing of the manuscript; ZZ and MH supervised the study. All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.