Energy intake and resting metabolic rate in preschool Jamaican children with homozygous sickle cell disease

Background: A relative energy deficiency consequent to a high resting metabolic rate (RMR) may contribute to growth impairment in persons with homozygous (SS genotype) sickle cell disease (SCD). The growth deficit in SCD emerges at an early age, but few studies have addressed the adequacy of energy intake relative to RMR in young children. Objective: Our objective was to test the hypothesis that energy intake relative to RMR is lower in children with SCD than in control subjects. Design: The dietary intake of 41 children with SCD and 31 control subjects with a normal hemoglobin genotype (AA) aged 3-6 y was assessed by weighing all food consumed during 3 d. RMR was determined with the use of indirect calorimetry. Results: The RMR in the children with SCD ((x) over bar SD: 5.47 +/- 0.93 MJ/d) was higher than that in the control subjects (5.19 +/- 1.3 MJ/d) after adjustment for sex and weight (P = 0.04). Energy intake did not differ significantly between the 2 genotype groups. The ratio of energy intake to RMR was lower in the children with SCD ((x) over bar SD: 1.13 +/- 0.33) than in the control subjects (1.35 +/- 0.38) after adjustment for sex and weight (P = 0.005). Conclusions: Prepubertal children with SCD fail to compensate for their higher RMR by increasing their energy intake. This observation is consistent with a hypothesis of a relative energy deficiency in SCD.