Headache in children with sickle cell disease: prevalence and associated factors.

OBJECTIVE: To compare the prevalence of frequent headache in children with sickle cell disease (SCD) to that of black control subjects and to assess factors associated with headache in SCD. STUDY DESIGN: In this cross-sectional study, a headache questionnaire was administered to subjects with SCD and black control subjects. Subjects answered supplementary questions about SCD complications. Clinical and radiographic information were abstracted from medical charts for subjects with SCD. RESULTS: Children (n = 241) with SCD and 141 control subjects were studied; 32.4% (95% CI 26.5%-38.7%) of subjects with SCD reported having headaches at least weekly, similar to control subjects at 27% (95% CI 19.8%-35.1%, P = NS); however, in children <13 years, headache was more common in subjects with SCD than in control subjects (24% vs 9.7%, P = .013). The prevalence of headache was similar among the different SCD genotypes. Factors associated with frequent headaches in subjects with SCD included older age, frequent vaso-occlusive pain episodes, symptoms of obstructive sleep apnea, and cerebral vessel stenosis detected by magnetic resonance angiography. CONCLUSION: The prevalence of headaches in children with SCD is similar to the general population; however, younger children with SCD report headaches more frequently than control subjects. The cause of headache is likely multifactorial, and SCD-specific factors may contribute.

Low vitamin D status in children with sickle cell disease.

OBJECTIVES: To examine vitamin D status in children with sickle cell disease (SCD)-SS and its relation to season and dietary intake. STUDY DESIGN: Growth, dietary intake, 25-hydroxyvitamin D (25-OHD), and parathyroid hormone levels were measured. Children with low and normal vitamin D status were compared. Low vitamin D status was defined as a serum concentration of 25-OHD <27.5 nmol/L. Serum 25-OHD and parathyroid hormone levels were compared among children with SCD-SS and healthy children. RESULTS: Children with SCD-SS (n=65), 5 to 18 years of age, were evaluated. Mean (+/-SD) serum 25-OHD concentration was 25.5 +/- 12.8 nmol/L; 65% of subjects had low vitamin D status. Low vitamin D prevalence was highest during spring (100%). Children with SCD-SS were at higher risk for low vitamin D status than healthy children. Vitamin D intake was lower in subjects with SCD-SS and low vitamin D than those with normal serum vitamin D status (P <.05). CONCLUSIONS: Low serum vitamin D status was highly prevalent in black children with SCD-SS. Vitamin D status was associated with season and dietary intake.

Vitamin A status, hospitalizations, and other outcomes in young children with sickle cell disease.

OBJECTIVE: To determine the relation of serum vitamin A status to growth, nutritional and hematologic status, and to the number of hospitalizations in children with sickle cell disease-SS (homozygous for the S allele, SCD-SS). STUDY DESIGN: Children (2-9.9 years of age) with SCD-SS were assessed for serum retinol, hemoglobin, hematocrit, reticulocyte count, height, weight, body mass index, and recalled dietary intake. Vitamin A status was defined on the basis of serum retinol concentration as suboptimal (<30 microg/dL) and normal (> or =30 microg/dL). Hospitalizations were determined for 1 year after vitamin A assessment. RESULTS: Mean serum retinol was 26.7 +/- 6.8 microg/dL in 66 subjects (39 girls) and was suboptimal in 66% of children. Compared with those with normal status, children with suboptimal vitamin A had significantly lower body mass index z score (-0.7 +/- 1.0 vs -0.1 +/- 0.6) and hemoglobin (7.9 +/- 1.1 vs 8.5 +/- 1.1), and hematocrit (23.3 +/- 3.0 vs 25.1 +/- 3.8) and significantly more hospitalizations (2.8 +/- 2.0 vs 0.7 +/- 0.8). After adjusting for age and sex, suboptimal vitamin A status was associated with a 10-fold increased risk for hospitalization (OR, 10.5; 95% CI, 2.3, 48.6) and with increased pain (OR,5.3; 95% CI, 1.3, 21.6) and fever episodes (OR, 6.4; 95% CI, 1.7, 24.9) requiring hospitalization. CONCLUSIONS: Suboptimal vitamin A status was prevalent in US children with SCD-SS and was associated with increased hospitalizations and poor growth and hematologic status.

Risk of recurrent stroke in children with sickle cell disease receiving blood transfusion therapy for at least five years after initial stroke.

OBJECTIVE: To test the hypothesis that children with sickle cell disease (SCD) who have an initial stroke temporally unrelated to another medical event are at higher risk for recurrent stroke than are children who had strokes temporally related to medical events. METHODS: A retrospective cohort study of children with SCD and stroke who received regularly scheduled blood transfusions for a minimum of 5 years was conducted. Medical records were examined for the documentation of antecedent or concurrent medical events (hypertension, acute chest syndrome, aplastic crisis, fever associated with infection, exchange transfusion) associated with physician contact within 14 days before the initial stroke. RESULTS: A total of 137 pediatric patients from 14 centers were studied. Mean age at first stroke was 6.3 years (1.4 to 14.0 years) with mean follow-up of 10.1 years (5 to 24 years). Thirty-one (22%) patients had a second stroke (2.2 per 100 patient years); 26 patients had an identified medical or concurrent event associated with their initial stroke. None of these patients had recurrent stroke 2 or more years after the initial event. The remaining 111 patients had an ongoing risk of recurrent stroke (1.9 per 100 patient-years) despite long-term transfusions (P =.038). CONCLUSIONS: The absence of an antecedent or concurrent medical event associated with an initial stroke is a major risk factor for subsequent stroke while receiving regular transfusions.

Effect of hydroxyurea on growth in children with sickle cell anemia: results of the HUG-KIDS Study.

OBJECTIVES: Although hydroxyurea is effective in treating adults with sickle-cell anemia (SCA), there is concern that it may adversely affect growth in children. We report the growth characteristics of patients in the Phase I-II pediatric hydroxyurea trial (HUG-KIDS) before and during treatment at the maximum tolerated dose for one year. STUDY DESIGN: Children and adolescents with SCA (n = 68), aged 5 to 16 years at baseline, reached the maximum tolerated dose and had serial height, weight, and Tanner stage measurements. Data from the Cooperative Study of Sickle Cell Disease (CSSCD) were used for comparison. Mixed-effects models were used to compare serial measurements as a function of age and group. RESULTS: In girls, there were no significant differences in height or weight among the pretreatment, on-treatment, and CSSCD groups. Compared with the CSSCD group, HUG-KIDS boys were heavier starting at age 9 years, and pretreatment HUG-KIDS boys were taller starting at age 7 years. The Tanner stage transitions took place at appropriate ages. CONCLUSIONS: Hydroxyurea treatment had no adverse effect on height or weight gain or pubertal development in school-aged children with SCA.