[Growth and endocrine function in major thalassemia].

Background: The risk of secondary endocrine dysfunction in patients with thalassemia major remains high, despite improvements in the care of hematologic problems.

Population and methods: 31 patients (15 males, 16 females) with thalassemia major were studied. 28 of them had been regularly given blood transfusions since the age of 3.7 +/- 3.6 years. Iron chelation therapy had started before the age of 10 years in 9 patients, after this age in 15 patients; it was not performed or the time not specified in the 7 others. The mean dosage of deferoxamine was 20 +/- 6 mg/kg/day (9.6-34 mg/kg/day). Endocrine functions were evaluated at a mean age of 11.8 +/- 4.9 years and were monitored for 6.1 +/- 4.6 years (0 to 19 years). The hormones assay were: growth hormone (GH), thyroid, adrenal cortex, parathyroid and gonadal functions.

Results: The GH peak after stimulation was normal, but plasma somatomedin CIGFI was low and did not increase at puberty. 6 patients had peripheral hypothyroidism. Plasma cortisol was normal in the 16 patients examined, but plasma dehydroepiandrosterone sulfate was low in 24; this might be partly responsible for the delayed development of pubic hair. 2 patients aged 20 and 27 years was suffered from diabetes mellitus. Hypoparathyroidism occurred in 7 patients and 12 of the 24 patients with impuberism had a gonadotropin deficiency. The mean final height was -1.3 +/- 1.0 SD in boys (n = 7, mean age: 20 +/- 1 yr) and -1.3 +/- 0.9 SD in girls (n = 7; mean age: 19 +/- 1 yr), whether puberty was spontaneous or induced.

Conclusions: The most frequent endocrine complications in these patients are delayed puberty because of gonadotropin deficiency, hypoparathyroidism and peripheral hypothyroidism. Substitution therapy, using sex steroids at an appropriate age, can induce the pubertal growth spurt.