Risk factors in underweight older children with sickle cell anemia: a comparison of low- to high-income countries.

Previously, we demonstrated that older children with sickle cell anemia (SCA) living in Nigeria are at increased risk of death if they are underweight (weight-for-age z score < -1). We now conducted a cross-sectional study in low- and high-income settings to determine the risk factors for being underweight a in children aged 5 to 12 years with SCA. The children from low- and high-income settings were eligible participants for the Primary Prevention of Stroke in Children with Sickle Cell Disease in Nigeria (SPRING; N = 928) and the Silent Cerebral Infarct (SIT, North America/Europe; N = 1093) trials, respectively. The median age in the SPRING and SIT cohorts was 8.1 and 8.5 years, respectively (P < .001). A total of 87.9% (n = 816) of participants in the SPRING trial (low-income) met the study criteria for being underweight (weight-for-age z score < -1), and 22.7% (n = 211) for severely underweight (weight-for-age z score < -3), significantly higher than the SIT (high-income) cohort at 25.7% underweight (n = 281) and 0.7% severely underweight (n = 8; P < .001 for both comparisons). In the combined cohort, older age (odds ratio [OR], 1.24; P < .001) and lower hemoglobin level (OR, 0.67; P < .001) were associated with being underweight. Age and hemoglobin level remained statistically significant in separate models for the SPRING and SIT cohorts. Older age and lower hemoglobin levels in children aged 5 to 12 years with SCA are associated with being underweight in low- and high-income settings.