The endocrine system in treated patients with classical galactosemia

Abstract

Endocrine abnormalities in classical galactosemia, female hypergonadotropic hypogonadism and low thyroxin in neonates, have been reported. Galactosemia is a secondary glycosylation disorder and hypoglycosylation of glycoproteins has a role in this dysfunction. Hypoglycosylation, improves but does not completely disappear with dietary treatment. Our aim was to evaluate the endocrine system in treated patients ( n = 37, 25 females, 12 males, age 5–19 years). Endocrine determinations were compared to age and gender matched reference ranges. Sample t-test (to test differences with reference population) and linear regression analysis between hGH (growth hormone), IGF-1 (insulin-like growth factor), IGFBP-3 (insulin growth factor binding protein), FSH (follicle stimulating hormone), LH (luteinizing hormone) and GALT activity, and soy intake, was carried out. Mean IGF-1 Z-score was −0.98 ± 0.84 (range −2.59 to 1.21) ( P < 0.001) in females and 0.03 ± 0.55 (range −1.0 to 0.89) ( P = 0.84) in males. Mean IGFBP-3 Z-score was −0.98 ± 1.3 (range −3.0 to 2.0) ( P < 0.001) in females and 0.26 ± 0.93 (range −0.94 to 2.0) ( P = 0.35) in males. IGF-1 and IGFBP-3 were positively correlated ( P < 0.001). IGF-1 or IGFBP-3 Z-scores and age, hGH, estradiol, GALT activity or soy intake were not correlated. FSH was elevated in females, other axes were normal. Besides the hypergonadotropic hypogonadism in females, IGF-1 and IGFBP-3 are in the low to normal ranges in girls. Hypoglycosylation in galactosemia is diet dependent and could worsen when galactose intake increases either because of poor compliance or diet liberalization.