Chest
Volume 148, Issue 4, October 2015, Pages 986-994
Journal home page for Chest

Original Research
COPD
Longitudinal Changes in Handgrip Strength, Hyperinflation, and 6-Minute Walk Distance in Patients With COPD and a Control Group

https://doi.org/10.1378/chest.14-2878Get rights and content

BACKGROUND

In COPD, a decreased inspiratory capacity to total lung capacity ratio (IC/TLC) is associated with dynamic hyperinflation and poor exercise capacity. The association with upper-extremity force measured by handgrip strength (HGS) and 6-min walk distance (6MWD) has not been previously described. We hypothesized that IC/TLC affects muscle strength in the upper and lower extremities, affecting HGS and 6MWD.

METHODS

We prospectively measured lung function, HGS, and 6MWD in 27 patients with COPD and 12 healthy nonsmokers twice, 1 year apart. The patients were classified according to level of hyperinflation: IC/TLC > 25% or IC/TLC ≤ 25%.

RESULTS

Patients with COPD had reduced lung function, static hyperinflation, and reduced HGS and 6MWD compared with the control subjects on both evaluations (P < .01). There was a statistically significant deterioration in HGS, IC/TLC, and 6MWD after 1-year follow-up in the COPD compared with the control group (P < .001). More hyperinflation (IC/TLC < 0.25) was associated with lower HGS and 6MWD (P < .001). Changes in IC/TLC correlated with changes in HGS (r = 0.429, P < .05). Multivariate analysis determined that IC/TLC is an independent factor associated with HSG and 6MWD.

CONCLUSIONS

HGS and 6MWD are reduced in patients with COPD, particularly in those with hyperinflation and evidence of longitudinal deterioration not seen in control subjects. This finding suggests that resting hyperinflation may exert a detrimental effect on cardiac function and plays a role in reduced exercise performance in patients with COPD.

Section snippets

Results

Patients and control subjects were similar in age, sex, height, weight, and BMI (Table 1). As expected, the patients with COPD presented with significantly (P < .01) lower values of FEV1, FEV1/FVC, and diffusing capacity of lung for carbon monoxide than the control subjects, without significant changes after 1-year follow-up. HGS was reduced in the COPD group compared with the control group at visit 1 (32 ± 11.1 kg vs 53 ± 2.6 kg; P «.01) and visit 2 (28 ± 9.2 kg vs 53 ± 2.7 kg; P < .01).

Discussion

This study of patients with COPD has three novel findings. First, a strong association exists between upper- and lower-extremity muscle impairment and static hyperinflation depicted by IC/TLC. Second, the degree of hyperinflation and muscle function impairment worsens over 1 year of observation, with relative preservation of the obstructive degree of lung function (FEV1). Third, decline in HGS and 6MWD and worsened IC/TLC were associated with increased heart rate at rest, showing that patients

Acknowledgments

Author contributions: V. P.-P. 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, including and especially any adverse effects. F. C. and B. C. contributed to the study design, data analysis and interpretation, and writing of the manuscript; M. D. contributed to the data collection, data analysis and interpretation, and review of the manuscript; and V. P.-P. contributed to the study design, data

References (28)

  • DE O'Donnell et al.

    Dynamic hyperinflation and exercise intolerance in chronic obstructive pulmonary disease

    Am J Respir Crit Care Med

    (2001)
  • DE O'Donnell

    Ventilatory limitations in chronic obstructive pulmonary disease

    Med Sci Sports Exerc

    (2001)
  • JM Marin et al.

    Inspiratory capacity, dynamic hyperinflation, breathlessness, and exercise performance during the 6-minute-walk test in chronic obstructive pulmonary disease

    Am J Respir Crit Care Med

    (2001)
  • C Casanova et al.

    Inspiratory-to-total lung capacity ratio predicts mortality in patients with chronic obstructive pulmonary disease

    Am J Respir Crit Care Med

    (2005)
  • Cited by (25)

    View all citing articles on Scopus

    FUNDING/SUPPORT: The authors have reported to that no funding was received for this study.

    originally published Online First May 21, 2015.

    View full text