Exercise Capacity, Physical Activity, Fatigue, and Neurocognitive Function in Adult Survivors of Childhood Acute Lymphoblastic Leukemia

ABSTRACT Background Adult survivors of childhood acute lymphoblastic leukemia (ALL) are at risk of reduced exercise capacity, decreased physical activity levels, persistent fatigue, and neurocognitive deficits. The aim was to investigate exercise capacity and physical activity levels of adult survivors of childhood ALL and their associations with neurocognitive outcomes, including processing speed and functional frontal cortical brain connectivity. Methods This cross‐sectional study included 47 adult survivors of childhood ALL; 29 (61.7%) were male, with a median age of 29 years (min–max 21–47). Participants completed questionnaires, a graded exercise test on a cycle ergometer, neurocognitive tests, and frontal cortical brain imaging with functional near‐infrared spectroscopy. Associations between predicted peak exercise capacity and fatigue (Fatigue Severity Scale [FSS]), processing speed (Processing Speed Composite), and functional frontal cortical network connectivity (global efficiency and modularity) were analyzed using linear regression. Parallel analyses were performed with physical activity level as the independent variable. Results Participants achieved a mean peak exercise capacity corresponding to 83.8% (standard deviation [SD] = 13.1) of the age‐ and sex‐predicted value ( p < 0.001), and 42.2% did not meet WHO‐recommended levels of physical activity. Statistically significant associations were identified between higher predicted peak exercise capacity and lower fatigue (FSS total score β = −0.33, 95% CI [confidence interval] −0.66 to −0.05, p = 0.02) and between higher physical activity levels and lower fatigue (FSS total score β = −0.4, 95% CI −1.8 to −0.2, p = 0.015). No other significant associations were found. Conclusion Adult survivors of childhood ALL had reduced exercise capacity, and a substantial proportion did not meet recommended physical activity levels. Exercise capacity and physical activity levels were associated with fatigue. No significant associations were observed with functional frontal cortical network connectivity or cognitive measures.