Associations Between Personality Traits and Longitudinal Change in Physical Function in Survivors of Childhood Cancer

OBJECTIVE: Exercise interventions for survivors of childhood cancer (survivors) focus on improving cardiovascular fitness and muscle strength. We aimed to examine associations between personality traits and change in physical function outcomes in survivors who completed a resistance training (RT) intervention. METHODS: Participants were 5+ year survivors in the St. Jude Lifetime Cohort. Personality traits were assessed using the Big Five Inventory 2 (BFI-2). Grip strength was measured using hand-held dynamometry. Quadriceps strength was measured using isokinetic dynamometry. Walking speed was measured with the Six-Minute Walk Test (6MWT). Associations between personality traits and grip strength, quadriceps strength, and walking speed were evaluated using multivariable regression adjusted for gender, age at assessment, race, primary cancer diagnosis, and grade 3-4 chronic health conditions (National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03). RESULTS: Among 43 survivors (mean age 34.6 ± 7.0 years, 55.8% female, 67.4% white, 41.9% leukemia/lymphoma, 3.84 ± 2.02 years post-intervention), mean trait scores were: agreeableness 4.2 ± 0.5, conscientiousness 3.9 ± 0.7, extraversion 3.4 ± 0.7, negative emotionality 2.6 ± 0.9, and open-mindedness 3.9 ± 0.7. Mean change post-intervention to follow-up in grip strength was -2.1 ± 11.9 kg, quadriceps strength -25.5 ± 27.2 Nm/kg, and walking speed 2.5 ± 14.0 m per minute. Survivors who scored higher in conscientiousness had greater positive change in walking speed from post-intervention to follow-up (β = 11.35, SE = 3.50, p = 0.003). CONCLUSION: Personality traits may impact the maintenance of physical function in survivors past intervention windows. Further interventions should consider personality and potentially tailor follow-up to preserve functioning.