Long-term results of growth hormone therapy in Turner syndrome

Epidemiology of Disorders Associated with Short Stature in Childhood: A 20-Year Birth Cohort Study in Finland

Background

Many primary and secondary disorders disturb growth and cause short stature (height below −2 SDS) in childhood. Growth monitoring programs aim at their early detection but are not evidence-based: epidemiology of childhood growth disorders is poorly characterized, and no consensus exists on priority target conditions. Herein, we describe population-based epidemiological data on several primary and secondary growth disorders associated with short stature in childhood.

Materials and Methods

This retrospective population-based 20-year birth cohort study examined 1 144 503 children (51% boys) born in Finland between 1998 and 2017, with 16.5 million care notifications including medical diagnoses. The first occurrences of key primary or secondary growth disorders were identified in multiple registers. Median ages at diagnosis (MAD), and age- and sex-specific cumulative incidences (CMI) from birth until 16 years of age were determined.

Results

Turner syndrome was the most common primary growth disorder (CMI 52 per 100 000 at 16 years, MAD 4.0 years). Most primary growth disorders were diagnosed before the age of 4 years, and thereafter, secondary growth disorders increased in number. MAD of growth hormone deficiency (GHD) was 8.7 (boys) and 7.2 years (girls). At 16 years, the CMI of GHD was higher in boys than in girls (127 versus 93 per 100 000, respectively), whereas the CMI of hypothyroidism was higher in girls (569 versus 306 per 100 000). Celiac disease was the most common secondary growth disorder and more common in girls than in boys (988 versus 546 per 100 000 at 16 years, respectively).

Conclusion

These population-based epidemiological data indicate that childhood growth monitoring should be age- and sex-specific. In the early childhood, the focus should be on primary growth disorders, and from preschool age also on secondary growth disorders. These results provide evidence for improving growth monitoring programs and diagnostic practices targeting on Turner syndrome, GHD, hypothyroidism, and celiac disease.

Validation of growth charts for girls with Turner syndrome

Growth charts, which describe the natural course of growth in Turner syndrome (TS) patients, are commonly used in studies in lieu of control groups. While analysing data, various charts produce different final height estimations and height-gain predictions. The choice of an appropriate chart should be the first task when assessing effects of growth hormone treatment. The purpose of this study was to establish the most appropriate growth chart for the subsequent analysis of growth rate in the patients with TS observed initially for a short time without treatment in our clinic. We propose the criteria that a standardised chart should meet. The obtained height-standardised values (height standard deviation score -- Ht SDS) should represent normal distribution with a mean of 0 and standard deviation of 1; their initial mean value and mean change in these values during observation without treatment should not be different from 0. We studied 62 untreated girls with TS using three different growth charts. The values of Ht SDS based on the Lyon chart showed a significant difference from normal distribution (p < 0.05). Only the mean value of an initiaent from 0 (p = 0.088). The mean change of the Ht SDS value based on Lyon and Ranke charts during the follow-up period was not statistically different from 0 (p > 0.05), whereas the difference was statistically significant when the Wisniewski chart was used. Only the Ranke chart correctly characterised TS girls in our clinic. This analysis indicates the importance of careful selection of an appropriate growth chart for an observed population, before applying it to evaluate the effects of hormonal therapy.

VEGF, bFGF, and their receptors in the endometrium of rhesus monkey during menstrual cycle and early pregnancy

A number of cytokines and growth factors are known to modulate proliferation and differentiation of human endometrium. In this study, the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and VEGF receptors, fms-like tyrosine kinase (Flt1) and kinase insert domain-containing region (KDR), and bFGF receptor 1 (Flg) were examined in the endometrium of rhesus monkey on Day 5, 10, 16, 20, 25 of menstrual cycle and on Day 19 of early pregnancy. Western blot analysis showed the specificity of the anti-human antibodies with the monkey tissue. The expression of mRNA and protein of VEGF was correlated with that of its receptor KDR, which was detected in epithelial, vascular, and myometrial cells. The localization of bFGF and its receptor Flg was similar to that of VEGF, except that the Flg was absent in the endothelial cells. Strong expression of VEGF and bFGF in the glandular epithelial cells was observed in the proliferative phase, declined in the secretory phase during the cycle. Stronger staining of these factors was also observed in the decidual cells of the pregnant uterus, as compared with the stromal cells of cycling uterus. No expression of Flt1 was detected in the tissue examined in this study. These data suggest that VEGF, bFGF, and their receptors play important roles in epithelial and stromal development, angiogenesis, and blood vessel function in the endometrium during the menstrual cycle and early pregnancy of the rhesus monkey.

Fas, FasL, Bcl-2, and Bax in the endometrium of rhesus monkey during the menstrual cycle

To study possible role and regulation of apoptosis occurred in primate endometrium, the expression of apoptosis-related molecules, Fas, FasL, B cell lymphoma/leukaemia-2 (Bcl-2), and Bax were analyzed in relation to occurrence of apoptosis and proliferation in the cycling endometrium of the rhesus monkey using immunohistochemistry and Western blot. The cell apoptosis and proliferation were evaluated by means of in situ 3'-end labeling and Ki67 immunostaining, respectively. The results showed that the expressions of Fas, Fas ligand (FasL), Bcl-2, and Bax were co-localized predominantly in the epithelial cells of the endometrium. Modest Fas staining with no obvious change was detected throughout the menstrual cycle, while the levels of FasL and Bax protein in the epithelial cells increased in the secretory phase when apoptosis was most prevalent. In contrast, epithelial immunostaining for Bcl-2 was maximal during the proliferative phase and decreased in the secretory phase. Bcl-2 immunoreactivity was also detected in some immunocytes. The coordinated expression of Fas, FasL, Bcl-2, and Bax in the cycling endometrium of the rhesus monkey suggests that the cyclic changes in endometrial growth and regression may be regulated by the balance of these factors under the action of ovary steroids.