Background: Pediatric organ transplant recipients may have elevated cardiovascular (CV) risk. Low cardiorespiratory fitness (CRF) may contribute to CV risk; however, studies of CRF in children following kidney transplantation (KTx) and liver transplantation (LTx) are limited.
Methods: Laboratory testing included assessment of CRF (VO2peak), muscle strength, and body composition (%fat). Field testing (FITNESSGRAM) included the PACER, curl-up, and sit-and-reach tests. Values obtained were compared to sex- and age-based criterion-referenced standards (Healthy Fitness Zone, HFZ). The Previous Day Physical Activity Recall was used to assess after-school physical activity (PA) participation. Independent t tests were used to compare groups.
Results: Twenty-five KTx and 11 LTx recipients were tested. The groups were similar in all measures. Both groups demonstrated below normative values for VO2peak and muscle strength. Only 4% of the KTx and 9% of the LTx recipients achieved the HFZ for the PACER and 24% of the KTx and 45% of the LTx attained the HFZ for the curl-up test. Approximately 44% of both groups had percent fat greater than the upper criterion value of the HFZ. Both groups reported spending only 8% of their after-school time participating in physical activity.
Conclusions: Pediatric KTx and LTx recipients have significantly reduced CRF, muscle strength, and physical activity. Routine counseling and encouragement for increased physical activity is recommended as a part of routine care. A randomized clinical exercise intervention trial after pediatric solid organ transplantation is warranted to determine the impact of such lifestyle intervention on improving physical fitness and cardiovascular health.