Leg lean mass correlates with exercise systemic output in young Fontan patients.

TitleLeg lean mass correlates with exercise systemic output in young Fontan patients.
Publication TypeJournal Article
Year of Publication2018
AuthorsAvitabile CM, Goldberg DJ, Leonard MB, Wei ZAlan, Tang E, Paridon SM, Yoganathan AP, Fogel MA, Whitehead KK
JournalHeart
Volume104
Issue8
Pagination680-684
Date Published2018 04
ISSN1468-201X
KeywordsAbsorptiometry, Photon, Adolescent, Adult, Anthropometry, Cross-Sectional Studies, Exercise, Female, Fontan Procedure, Humans, Leg, Male, Muscle, Skeletal, Oxygen Consumption, Prospective Studies, Thinness, Young Adult
Abstract

OBJECTIVE: We previously described lower leg lean mass Z-scores (LLMZ) in Fontan patients associated with worse peak oxygen consumption on metabolic exercise testing. We hypothesised that LLMZ correlates with indexed systemic flow (Qsi) and cardiac index (CI) on exercise cardiac magnetic resonance (eCMR).

METHODS: Thirteen patients had LLM measured by dual-energy X-ray absorptiometry within mean 40 (range 0-258) days of eCMR. LLM was converted to sex and race-specific Z-scores based on healthy reference data. Ventricular volumes and flow measurements of the ascending and descending (DAO) aorta and superior vena cava (SVC) were obtained by CMR at rest and just after supine ergometer exercise to a heart rate associated with anaerobic threshold on prior exercise test. Baseline and peak exercise measures of Qsi (SVC+DAO/BSA) and CI, as well as change in Qsi and CI with exercise, were compared with LLMZ by linear regression.

RESULTS: LLMZ was not correlated with resting flows, stroke volume or CI. There was a strong linear correlation between LLMZ and change in both CI (r=0.77, p=0.002) and Qsi (r=0.73, p=0.005) from rest to exercise. There was also a significant correlation between LLMZ and Qsi at exercise (r=0.70, p=0.008). The correlation between LLMZ and CI at exercise did not reach significance (r=0.3, p=0.07).

CONCLUSIONS: In our cohort, there was a strong linear correlation between LLMZ and change in both CI and Qsi from rest to exercise, suggesting that Fontan patients with higher LLMZ may be better able to augment systemic output during exercise, improving performance.

DOI10.1136/heartjnl-2017-311661
Alternate JournalHeart
PubMed ID28988207
PubMed Central IDPMC7831371
Grant ListK23 HL089647 / HL / NHLBI NIH HHS / United States
R01 HL098252 / HL / NHLBI NIH HHS / United States
T32 HL007915 / HL / NHLBI NIH HHS / United States
UL1 TR000003 / TR / NCATS NIH HHS / United States
K24 DK076808 / DK / NIDDK NIH HHS / United States
UL1 RR024134 / RR / NCRR NIH HHS / United States