Lung transplantation (LTx) is offered to older and more complex patients who may be at higher risk of skeletal muscle dysfunction, but the clinical implications of this remain uncertain. The study aims were to characterize deficits in skeletal muscle mass, strength and physical performance, and examine the associations of these deficits with clinical outcomes.
Fifty LTx candidates (58% men; age, 59 ± 9 years) were prospectively evaluated for skeletal muscle deficits: muscle mass using bioelectrical impedance, quadriceps, respiratory muscle and handgrip strength, and physical performance with the Short Physical Performance Battery. Comparisons between number of muscle deficits (low muscle mass, quadriceps strength and physical performance) and 6-minute walk distance (6MWD), London Chest Activity of Daily Living Questionnaire, and quality of life were assessed using one-way analysis of variance. Associations with pretransplant and posttransplant delisting/mortality, hospital duration, and 3-month posttransplant 6MWD were evaluated using Fisher exact test and Spearman correlation.
Deficits in quadriceps strength (n = 27) and physical performance (n = 24) were more common than muscle mass (n = 8). LTx candidates with 2 or 3 muscle deficits (42%) compared with those without any deficits (26%) had worse 6MWD = −109 m (95% confidence interval [CI], −175 to −43), London Chest Activity of Daily Living Questionnaire = 18 (95% CI, 7-30), and St. George's Activity Domain = 12 (95% CI, 2-21). Number of muscle deficits was associated with posttransplant hospital stay (r = 0.34, P = 0.04), but not with delisting/mortality or posttransplant 6MWD.
Deficits in quadriceps muscle strength and physical performance are common in LTx candidates and further research is needed to assess whether modifying muscle function pretransplant can lead to improved clinical outcomes.
In 50 lung transplant candidates prospectively evaluated for skeletal muscular deficits, the authors describe common deficits in quadriceps muscle strength and physical performance without impact on delisting or mortality.
1 Department of Medicine, Respirology, University of Toronto, Toronto, ON, Canada.
2 Lung Transplant Program, University Health Network, Toronto, ON, Canada.
3 Critical Care, University Health Network, Toronto, ON, Canada.
4 Respirology, West Park Health Care Center, Toronto, ON, Canada.
5 Department of Physical Therapy, University of Toronto, Toronto, ON, Canada.
Received 6 December 2016. Revision received 28 February 2017.
Accepted 17 March 2017.
This work was presented in part at the ISHLT meeting in 2015 (Nice, France). Reference: Rozenberg D, et al. The Journal of Heart and Lung Transplantation, 34 (4), S251, April 2015.
D.R. receives salary support from the University of Toronto, Clinician Scientist Training program. He has received Canadian Institutes of Health Research (CIHR) Master’s Award, Vanier Graduate Scholarship and American Society of Transplant Fellowship. L.G.S., L.W., and S.M. have received research support from the Ontario Thoracic Society.
D.R., L.G.S., M.H., R.G., L.W., N.A.C., and S.M. made substantial contributions to the conception and design of the work. D.R. wrote the first draft of the article and L.G.S., M.H., R.G., L.W., N.A.C., and S.M. revised the article for important intellectual content. All authors made substantial contributions to the analysis or interpretation of data. All authors approved the manuscript and agree to be accountable for all aspects of the work ensuring that questions related to the accuracy or integrity of the work are appropriately investigated and resolved.
Correspondence: Sunita Mathur, PT, PhD, Department of Physical Therapy, University of Toronto, 160-500 University Ave, Toronto, ON, Canada M5G 1V7. (email@example.com).