Endocrine and Metabolic Complications in Children and Adolescents with Sickle Cell Disease: An Italian Cohort Study

Background: Children with Sickle Cell Disease (SCD) show endocrine complications and metabolic alterations. The physiopathology of these conditions is not completely understood: iron overload due to chronic transfusions, ischemic damage, and inflammatory state related to vaso-occlusive crises may be involved. Aims of this study were to evaluate the growth pattern and the endocrine and metabolic alterations in a cohort of children with SCD and to detect the relationship between these conditions and the SCD severity. Methods: Fifty-two children and adolescents with SCD [38 homozygous sickle hemoglobin (HbSS) and 14 heterozygous sickle hemoglobin (HbSC); age range 3-18 years] were recruited. Anthropometric [height, body mass index (BMI), arm span, sitting height, target height (TH), and pubertal status] and laboratory [blood cell counts, hemolysis indices, metabolic and nutritional status indices and hormonal blood levels] data were evaluated. The SCD severity was defined according to hematological and clinical parameters. Results: Height-SDS adjusted for TH and z-score-BMI were significantly higher in HbSC children than in HbSS ones. The 92% (48/52) of the population show at least one metabolic and/or endocrine alteration: insufficiency/deficiency of vitamin D (84.7%), insulin resistance (11.5%), growth hormone deficiency (3.8%), subclinical hypothyroidism (3.8%), and hypogonadism (1.9%). Levels of 25-hydroxy-vitamin D were negatively correlated with clinical indicators of the SCD severity. Subjects with HbSS genotype show significant lower levels of both insulin-like growth factor-I (IGF-1) and insulin-like growth factor binding protein 3 than children with HbSC. In the study group IGF-1 values were positively related with Hb and negatively related with lactate dehydrogenase. Conclusions: Metabolic and endocrine alterations are very common in children and adolescents with SCD. A regular follow-up is necessary to identify subjects at risk for complications, to precociously initiate an appropriate treatment, and to improve the quality of life of SCD patients.