The Comprehensive Assessment of Physical Fitness in Children Following Kidney and Liver Transplantation

Abstract

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. 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. 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. 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.