A CROSS-SECTIONAL STUDY OF GROWTH, PUBERTY AND ENDOCRINE FUNCTION IN PATIENTS WITH THALASSEMIA MAJOR IN HONG-KONG

Methodology: A cross-sectional study of growth, puberty and endocrine function was performed on 35 girls and 33 boys with thalassaemia major. Results: Despite regular transfusion and chelation therapy, 75% of the girls and 62% of the boys over the age of 12 years were below the third percentile for height. Hypogonadotropic hypogonadism was found in a similar percentage of patients. Moderate to marked zinc deficiency secondary to chelation therapy was considered unlikely because normal serum zinc levels were found in all but three of our patients, but we could not exclude the possibility of a marginal status of zinc nutrition causing growth failure. Growth hormone deficiency and diabetes mellitus were sometimes encountered but hypothyroidism, hypoparathyroidism and adrenal insufficiency were rare among our patients. Most of the patients with growth failure had normal growth hormone (GH) response to insulin induced hypoglycaemia. The serum insulin-like growth factor-1 (IGF-I) levels were low in our patients and no significant difference in the serum IGF-I levels was found between prepubertal children with or without growth failure (0.4 +/- 0.1 mU/mL vs 0.37 +/- 0.11 mU/mL, P = 0.39). Similarly, no difference in the serum IGF-I levels was found between pubertal children with or without growth failure (0.48 +/- 0.2 U/mL vs 0.56 +/- 0.14 U/mL, P = 0.26). Conclusions: Delayed sexual maturation and a possible defect in growth unrelated to the GH-IGF-I axis may be responsible for the growth failure in adolescent children with thalassaemia major.