Bone age progression during five years of substitutive therapy for the induction of puberty in thalassemic girls--effects on height and sitting height.
It is known that in thalassemic patients there is a disproportion between lower and upper segments whose causes have not yet been identified. We evaluated whether the administration of estrogens to induce puberty in hypogonadic thalassemic girls caused an inappropriate acceleration of bone maturation and whether this had a negative influence on final and sitting height.


METHODS
Twelve thalassemic patients with spontaneous puberty (Group A) and seven patients with hypogonadism (Group B) were studied. The mutations of the beta gene were identified by DNA analysis. We took into account four observations, ranging from the onset of spontaneous puberty in group A or the start of substitutive therapy in group B, to 5 years later. At each observation we considered: chronological age (CA), bone age (BA), height (Ht) expressed in cm and as standard deviation score (HtSDS) calculated with respect to CA (HtSDSCA) and BA (HtSDSBA), growth spurt, sitting height, expressed as SDS (SH-SDS), and height gain (HG). The delta BA and delta CA were calculated between the first and the final observation values to evaluate the bone age acceleration (delta BA/delta CA).


RESULTS
No acceleration of BA was noted. delta BA/delta CA was 0.98 +/- 0.1 in group A and 0.89 +/- 0.1 in group B (p > 0.05). All patients in group B had the most severe form (beta degree/beta degree) of thalassemia. During the final observation, SH-SDS was -1.43 +/- 1.2 and -2.9 +/- 0.6 in group A and B respectively (p < 0.002), while no difference between the two groups for HtSDSCA and HtSDSBA was observed. HG was greater in group A than in group B (17.7 +/- 5.4 cm vs 10.8 +/- 5.2 cm) (p < 0.002), such as the spurt 8.6 +/- 1.4 cm (group A) and 6.1 +/- 2.6 cm (group B) (p < 0.05).


CONCLUSIONS
Girls with hypogonadism did not show an inappropriate acceleration of BA, as they reached near final height similar to girls with spontaneous puberty. The auxological parameters showed a more severe body disproportion with the prevalence of the lower segment in the hypogonadic girls. This could be explained by a higher degree of bone marrow hyperplasia related to the most severe form of thalassemia and a higher blood consumption. As a consequence, damage at the vertebral level might determine an inability of the bone tissue to respond to estrogens. We suggest beginning estrogen therapy earlier in order to obtain better truncal growth.
Filosa
A
A
XXIX Paediatric Division, Cardarelli Hospital, Naples, Italy.
Di Maio
S
S
Lamba
M
M
Baron
I
I
Saviano
A
A
Esposito
G
G
D000293:Adolescent; D000328:Adult; D000365:Age Determination by Skeleton; D001827:Body Height; D002614:Chelating Agents / Q000009:adverse effects / Q000627:therapeutic use; D003676:Deferoxamine / Q000009:adverse effects / Q000627:therapeutic use; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007006:Hypogonadism / Q000188:drug therapy / Q000209:etiology; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000627:therapeutic use; D011187:Posture; D011628:Puberty, Delayed / Q000188:drug therapy* / Q000209:etiology; D017086:beta-Thalassemia / Q000150:complications* / Q000188:drug therapy
D002614:Chelating Agents; D004997:Ethinyl Estradiol; D017258:Medroxyprogesterone Acetate; D003676:Deferoxamine