Patterns and energy expenditure of free-living physical activity in adolescents with sickle cell anemia

Abstract

Objective: Our purpose was to examine the relationship between physical activity (PA), PA-associated energy expenditure (PAEE), and total daily energy expenditure (TEE) in free-living adolescents with sickle-cell anemia (SCA). Study design: Adolescents with SCA (n = 28) were matched for sex and age with 22 healthy control participants. PA was measured for 6 to 8 consecutive days with a triaxial accelerometer and resting energy expenditure (REE) by whole-room indirect calorimetry. TEE was calculated by summing PAEE and REE. Results: TEE was similar, REE was higher (difference, 209 kcal×day–1; P = .0001), and PAEE was lower (difference, 657 kcal×day–1; P < .001) in patients with SCA than in control participants. In SCA, there was a positive linear relationship between PAEE and hemoglobin concentration (r2 = 0.583). Time spent in PA of moderate and high intensity was lower in patients with SCA than in control participants (18 ± 22 vs 48 ± 31 min/d; P < .0001). Conclusion: In adolescents with SCA under free-living conditions, there is a significant intra and interindividual variability in the amount of PA, PAEE, and PA patterns. Because of a lower PAEE and a higher REE, TEE is similar in adolescents with SCA and healthy adolescents. An association of PAEE with hemoglobin concentration may be a part of an energy saving compensatory mechanism in SCA. (J Pediatr 2002;140:86-92)