Physical fitness and cardiac function in childhood cancer survivors.

Abstract

Objectives: Childhood cancer treatment has long-term health sequelae but there is more controversy for physical fitness. We compared fitness and echocardiographic variables in childhood cancer survivors (CCSs) and controls. A secondary aim was to determine the potential role of previous enrollment in inpatient exercise, and of current physical activity (PA) levels.

Design: Cross-sectional.

Methods: CCSs (age = 5-18 yrs, ≥4 yrs since diagnosis) and controls (no cancer history) were recruited. Outcomes included anthropometric, cardiorespiratory fitness (CRF)-related variables, upper/lower-body muscle strength (5-repetition maximum), functional mobility (timed up and down stairs [TUDS] test), and echocardiography. We performed sub-analyses attending to previous enrollment in supervised exercise training during intensive treatment and current accelerometer-determined PA.

Results: 126 CCSs (12.8 ± 3.2 yrs, 41 % female) and 497 controls (11.2 ± 3.3 yrs, 40 % female) were studied. CCSs had a higher body mass index (+1.6 kg/m², p < 0.001). Despite no significant differences in peak oxygen uptake (-0.5 %, p = 0.900), CCSs had lower ventilatory threshold (-9.8 %, p = 0.018), strength (-42.9 to -52.2 % depending on the analyzed exercise, p < 0.001 for most exercises) and TUDS performance (-23 %, p < 0.001) values than controls. CCSs showed a higher prevalence of left-ventricle hypertrophy and concentric cardiac remodeling. These results were independent of inpatient exercise background. CCSs showed lower levels of moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) (p < 0.005). In CCSs, a positive correlation was found between MVPA/VPA levels and CRF or strength-related variables (all r > 0.4, p < 0.05).

Conclusions: CCSs showed impairments in some physical fitness and cardiac parameters ≥4 yrs posttreatment, which seemed independent of previous inpatient exercise background but not of MVPA/VPA levels after treatment.