Growth, upper arm anthropometry and serum 25-hydroxyvitamin d status of brazilian and nigerian school-aged children with sickle cell disease
Data
2016-10-27
Autores
Adegoke, Samuel Ademola 
Orientadores
Figueiredo, Maria Stella
Tipo
Tese de doutorado
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Resumo
BACKGROUND: Sickle cell disease (SCD) phenotype is very variable and many genetic and environmental modulating factors including nutritional status have been implicated. Comparative studies of patients in different socio-geographic and ecological zones afford an opportunity to investigate potential environmental and other factors that influence the phenotype. OBJECTIVES: To assess the growth parameters, upper arm anthropometry, and serum 25-hydroxyvitamin D (25-OHD) of two cohorts of children with SCD at the University Teaching Hospitals in Ile-Ife/Ilesa, Southwest, Nigeria, and Sao Paulo, Brazil. In addition, the study also sought to determine the influence of hydroxyurea (HU) on growth and nutritional status. Relationship between serum 25-OHD and disease phenotypes (rates of pain episodes, biomarkers of intravascular haemolysis and inflammatory cytokines) was also determined. METHODS: Sociodemographic, clinical, growth and upper arm anthropometry of school-aged Brazilian and Nigerian children with SCD as well as age- and sex-matched haemoglobin AA Nigerian controls were assessed. Haematological and biochemical parameters (serum 25-OHD inclusive); and inflammatory cytokines were determined by standard techniques. Relationships between serum 25-OHD, pain rates and cytokines were determined by statistical tests. Nigerian SCA children with suboptimal 25-OHD were given 2,000 IU of vitamin D3 supplemetation daily for three months and its infuence on cytokine profiles was evaluated. RESULTS: A relatively high proportion of the children in both centers (23.5 percent) were underweight. Weight, BMI-Z score, height for age-Z score, upper arm fat area and fat percentage were significantly lower in the Nigerian than Brazilian cohorts. A higher proportion of Nigerian patients (29.5% against 19.3%) were underweight, and of short stature (12.6% vs. 3.7%), while a higher proportion of Brazilian patients were overweight or obese, (9.2% vs. 4.3%) and taller for age, (16.5% vs. 8.4%). None of the Nigerian patients had severe vitamin D deficiency and only 12.6% had suboptimal vitamin D levels, however, 3.7% of the Brazilian patients had severe deficiency and majority, 79.8% had either vitamin D deficiency or insufficiency. Underweight and severe vitamin D deficiency were more prevalent among Brazilian children who were hydroxyurea-naive than those who had used HU for at least 12 months (30.6% vs. 13.7%, p = 0.036; and 11.4% vs 0%, p = 0.008 respectively). Their mean serum 25-OHD was also lower than the HU group, 20.80 ± 7.48 ng/ ml vs. 24.52 ± 8.26 ng/ml, p = 0.021. All Nigerian children with suboptimal vitamin D compared to 69.7% of those with normal vitamin D experienced vasoocclusive pain episodes in the preceding 12 months, p = 0.037, 95% CI = 0.7 ? 0.9. The mean serum vitamin D of those with at least one pain episode (41.25 ± 10.09 ng/mL), was significantly lower than 45.22 ± 7.71 ng/mL for those without pain episode, p = 0.043, 95% CI = 1.3 ? 7.8. After excluding the potential influence of HU, among Brazilian patients, hemoglobin and hematocrit had significant positive correlations with serum 25-OHD (r = 0.40, p = 0.017 and r = 0.45, 0.006 respectively), while reticulocyte percentage, absolute reticulocyte count and serum lactate dehydrogenase (LDH) had significant inverse correlation (r = -0.44, p = 0.008; r = -0.47, p = 0.007 and r = -0.45, p = 0.007 respectively). Also, the mean hemoglobin of those with suboptimal vitamin D was lower (8.1 ± 0.9g/dl vs. 9.4 ± 1.8g/dl, p = 0.014), while the mean reticulocyte count and serum lactate dehydrogenase were significantly higher, p = 0.047 and 0.003 respectively.Compared to those with normal level, Nigerian patients with suboptimal 25-OHD had significantly higher serum pro-inflammatory cytokines IL-6, 8 and 18 (p = 0.003, 0.010 and 0.002 respectively) and lower levels of anti-inflammatory cytokine IL-11 (p = 0.005). Proinflammatory cytokines IL-2, 6, 8, 17 and 18 were reduced significantly while antiinflammatory cytokines IL-11 was significantly higher at the end of 3 months of vitamin D3 supplementation. CONCLUSIONS: Nigerian children with SCD were lighter, shorter and had less fat than their Brazilian counterparts. On the contrary, more Brazilian children had overweight/ obesity, with majority having suboptimal serum 25-OHD levels. HU therapy tends to protect against growth retardation and vitamin D deficiency. A possible association between depressed serum vitamin D level and increased frequency of acute pain episodes supports the role of vitamin D in musculoskeletal health. Also the correlation between serum 25-OHD levels and biomarkers of intravascular haemolysis and inflammation suggest its role in the pathogenesis of haemolytic and inflammatory phenotypes in children with SCD.
Descrição
Citação
ADEGOKE, Samuel Ademola. Growth, upper arm anthropometry and serum 25-hydroxyvitamin d status of brazilian and nigerian school-aged children with sickle cell disease. 2016. 156 f. Tese (Doutorado em Medicina: Hematologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2016.