Groeiremming Met Oestrogenen Bij Constitutioneel Te Lange Meisjes

Childhood growth and exposure to dichlorodiphenyl dichloroethene and polychlorinated biphenyls

OBJECTIVES

Dichlorodiphenyl dichloroethene (DDE) and polychlorinated biphenyls (PCB), toxic contaminants known to be persistent in the environment, may affect growth. We investigated whether growth from birth to 10 years of age is associated with blood concentrations of DDE and PCB taken at 8 years of age.

STUDY DESIGN

We ambispectively followed up a cohort of 343 German children. DDE and PCB blood concentrations were determined in 1995. Height measurements were conducted prospectively between 1994 and 1997 and obtained retrospectively from each Child's Health Card. Linear regression models for repeated measurements, controlling for confounding factors, were applied.

RESULTS

Growth was significantly reduced by an average of 1.8 cm (P <.0275) for girls in the highest DDE concentration quartile (>.44 microg/L in whole blood) compared with girls in the lowest quartile (0.08-0.2 microg/L). There was no observed growth effect of DDE in boys. PCB blood concentrations were not related to growth reduction in either girls or boys.

CONCLUSIONS

Background level concentrations to DDE, but not PCB, during childhood are associated with a small reduction in growth for girls evident through the age of 8 years. The observed differences narrow at the year 9 examination and disappear at the year 10 examination. No effects on boys' heights were observed.

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.

MATERIALS AND 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.

Short-term effects of high dose estrogen on tibiae of growing male rats

The short-term effects of estrogen at a single high dose (4 mg/kg body weight/day for 14 days) were determined on tibiae in the normal (noncastrate) growing male rat. In cortical periosteal bone, at a middiaphyseal site devoid of resorbing activity, estrogen suppressed periosteal bone formation and apposition rates, resulting in a smaller cross-sectional area. In middiaphyseal endocortical bone, estrogen had no effect on apposition and formation rates and, because medullary area was unchanged, probably had no effect on endocortical bone resorption. In the proximal tibial metaphysis, estrogen greatly suppressed longitudinal growth rate. In a site within the metaphysis adjusted for the effects of growth, cancellous mineral apposition was greatly reduced by the hormone. Estrogen-treated rats retained more of a fluorochrome label deposited in cancellous bone at the beginning of the study than vehicle-treated animals, indicating a reduced net bone loss. As a result of the lowered resorption induced by estrogen, cancellous bone mass (area and perimeter) were both significantly higher in estrogen-treated rats. No evidence was found for an anabolic action of the hormone in the male rat; indeed, estrogen reduced indices of bone formation.