Bone Area and Bone Mineral Content Deficits in Children With Sickle Cell Disease

Abstract

Objective. Children with sickle cell disease (SCD) experience poor growth, altered body composition, and delayed maturation. Deficits in bone mineral content (BMC) and bone area (BA) have not been well characterized. The objectives of this study were to assess whole-body BMC (WBBMC) and WBBA in children with SCD, type SS (SCD-SS), compared with healthy control subjects, adjusted for growth and body composition, and to determine the relationships of WBBMC and WBBA to bone age and hematologic parameters in children with SCD-SS. Methods. WBBMC, WBBA, and lean mass were measured by dual-energy x-ray absorptiometry in children who were aged 4 to 19 years. Growth, sexual development, and bone age were assessed. Gender-specific z scores for WBBMC relative to age and height were generated from control data. Results. Ninety children with SCD-SS and 198 healthy control subjects were evaluated. SCD-SS was associated with poor growth. WBBMC was significantly decreased in SCD-SS compared with control subjects, adjusted for age, height, pubertal status, and lean mass. WBBMC relative to age and WBBMC relative to height z scores were −0.95 ± 0.99 and −0.54 ± 0.97, respectively, and were associated with hemoglobin and hematocrit levels and history of delayed bone age. Conclusions. Children with SCD-SS have significant deficits in WBBMC that persist despite adjustment for poor growth and decreased lean mass. These children may be at increased risk for fragility fractures and suboptimal peak bone mass.