Let’s get physical: Aerobic capacity, muscle strength, and muscle endurance in pediatric transplant recipients

  • Author / Creator
    Allan, Chantal J
  • Pediatric heart and kidney transplant recipients appear to have lower physical fitness than healthy children. This study sought to quantify the fitness level of transplant recipients and investigate clinical and lifestyle factors that may affect physical fitness. First, a systematic review and meta-analysis of existing literature about fitness after pediatric transplantation was conducted. Several databases were searched for peer-reviewed publications since 1990. Articles were selected for their relevance to age (0-18 years), condition (heart, lung, kidney, liver, or bone marrow transplant), methodology (at least one fitness assessment), and comparator (healthy control or normative values). Transplant recipients were compared to healthy children, and were analyzed in sub-groups of type of organ transplant and type of fitness test. Thirty-two studies were included in the final qualitative synthesis, and 24 of those were included in the meta-analysis. There were 13 studies in heart transplant (HTx) recipients, 11 in kidney transplant (KTx) recipients, 5 in liver transplant (LiTx) recipients, 4 in bone marrow transplant (BMT) recipients, and 0 in lung transplant recipients. VO2max was not significantly different between types of organ transplant. The mean difference in VO2max between studies in BMT was 12.18 (10.23, 14.12) ml/kg/min, in HTx was 11.89 (10.85, 12.94) ml/kg/min, in KTx was 11.74 (10.22, 13.25) ml/kg/min, and in LiTx was 9.87 (7.14, 12.60) ml/kg/min. There were no consistent methods for measuring muscle function in transplant recipients, except curl-ups were measured in LiTx, and there was no difference between LiTx and controls for this test. Next, a prospective trial was developed to address gaps in the literature, and gain a deeper understanding of the underlying causes of fitness impairment in children living with transplants. Aerobic capacity (6MWT), muscle strength (hand-held dynamometry), muscle endurance (push-ups, curl-ups, wall-sit), physical activity level (PAQ), and quality of life (PedsQL 4.0) of HTx and KTx recipients were measured at a one-time, 1.5-hour fitness assessment. Clinical variables were collected from patient charts. Twenty controls, 22 HTx, and 6 KTx recipients were included in the study. All groups were similar in age, but the KTx group was shorter (125.8 (110.5-150.9) cm) than the control (150.6 (116.5-187.9) cm) and HTx groups (137.9 (110.0-180.7) cm). The age at transplant and time post-transplant were similar in HTx and KTx groups. 6MWT percent predicted distance was shorter in HTx (87.2 (69.9-118.6) %) than controls (99.9 (80.4-120) %). Muscle strength was lower in the upper body of HTx (6.15 (4.35-11.3) kg/m2) versus controls (8.48 (4.80-10.8) kg/m2), and in the lower body of KTx (9.27 (8.65-19.1) kg/m2) versus controls (15.4 (11.7-21.3) kg/m2). Muscle endurance was lower in the upper body of both HTx (28.6 (0.00-250) %) and KTx (8.35 (0.00-150) %) versus controls (112 (48.9-400) %), in the core of HTx (115 (0.00-450) %) versus controls (167 (46.7-500) %), and in the lower body of KTx (18.5 (10.0-54.0) s) versus controls (62.0 (11.0-203) s). 6MWT percent predicted distance was moderately correlated with stroke (R=-0.562, P<0.01), but not persisting neuromotor deficits from stroke (R=-0.351, P=0.11), when analyzed by rank bivariate analysis. No other clinical variables were correlated with 6MWT percent predicted distance or wall-sit time. Recipients of different types of transplant have similar changes in aerobic capacity, but different changes in muscle function as compared to healthy children. This finding would suggest that transplantation has a similar effect on overall fitness level, but different effects on muscle function depending on the type of transplant and duration of corticosteroid use. Further studies are needed to provide more information about the differences in muscle strength and endurance in different types of pediatric transplant. In the interim, physical therapy or physical activity interventions may help to improve the fitness level of pediatric transplant recipients.

  • Subjects / Keywords
  • Graduation date
    Fall 2018
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.