An improvement in hemoglobin of 1.1 g/dL in patients with sickle cell disease (SCD) may be sufficient to significantly improve neurocognitive and educational outcomes, according to a study published in PLoS One. 

Patients with SCD have to contend with lifelong complications, among them painful vaso-occlusive crises and the increased risk of life-threatening conditions such as silent cerebral infarcts. Studies also indicate that SCD reduces intellectual function and impedes academic achievement. 

There is some evidence to suggest that increasing hemoglobin levels and oxygen saturation levels may positively impact intelligence, but data on this are scarce. The authors of the study conducted a study to assess how hemoglobin-improving therapies impact academic performance and educational attainment. 

The research team built a cohort simulation model to reflect the pediatric population with SCD. Intelligence and cognitive function was measured in terms of intelligent quotient (IQ), which in turn impacts academic results. The pediatric SCD cohort was designed to mirror that of real-world individuals with SCD (by, for example, having a greater proportion of individuals with African American/Hispanic descent). The model had 2 key stages: childhood, defined as those under 10 years of age, and adolescence, defined as children 10 years of age and above. 

Read more about SCD etiology 

In the first stage of the study, researchers assigned a rise in hemoglobin and oxygen saturation levels to the group receiving therapy. This directly and independently improved IQ and prevented it from deteriorating over time. Among individuals not receiving these therapeutics, the opposite was the case. The researchers also reported that the therapy group had a significantly lower risk of stroke compared with the nontherapy group.

In the second stage of the study, IQ was assigned as a determinant of academic performance and achievement, as indicated by the Armed Forces Qualification Test scores, years of education completed, and cognitive and noncognitive skills. The researchers reported that all of these parameters improved among members of the treatment group. 

“These [neurocognitive and educational] improvements may also generate benefits not captured by our model, including improved quality of life, employment, and income among individuals with SCD,” the authors concluded. 


MacEwan JP, King AA, Nguyen A, Mubayi A, Agodoa I, Smith-Whitley K. Cognition and education benefits of increased hemoglobin and blood oxygenation in children with sickle cell diseasePLoS One. Published online August 8, 2023. doi:10.1371/journal.pone.0289642