Long acting analogs of gonadotropin releasing hormone (GnRHas) have been the gold standard for the treatment of central precocious puberty (CPP) worldwide, and have an enviable track record of safety and efficacy. Recent years have witnessed significant growth in the availability of longer acting and sustained release forms of GnRHas. While all available agents appear promising, limited long-term follow up and/or comparative data are available. In this review, important issues pertaining to the treatment of children with CPP will be discussed. In addition to an assessment of the newer extended release GnRHa formulations, a delineation of factors essential in determining which children should be treated will be offered. Outstanding uncertainties in clinical management will be highlighted, and areas in need of future research identified. Literature searches for this review were performed in PubMed and OVID with a focus on English language publications utilizing the terms “central precocious puberty” and “treatment”.
1 June 2019 in Best Practice & Research Clinical Endocrinology & Metabolism
Concerns about psychological distress are often used to justify treatment of girls with precocious puberty, but there is little evidence to support these concerns. The extent to which psychological problems are associated with central precocious puberty (CPP) compared with other forms of early puberty in girls has likewise not been established. Girls presenting with untreated CPP, premature adrenarche (PA) or early normal puberty (ENP) were recruited from our pediatric endocrine clinic along with their mothers. Child psychological adjustment was assessed by child self-report and parent report. Parent self-reported personality, anxiety, and depression were also assessed. Differences between groups were explored using one-way ANOVA and Dunnett's T3 test. Sixty-two subjects (aged 7.5 ± 1.4 years, range 4.8-10.5) were enrolled, of whom 19 had CPP, 22 had PA, and 21 had ENP. Girls with ENP were significantly older (8.9 ± .9 years) than girls with CPP (6.9 ± 1.1 years, p < .001) and PA (6.6 ± 1.0 years, p < .001). Girls with PA had significantly higher BMI z-scores (1.7 ± .8) than girls with CPP (1.1 ± .6, p = .01) and ENP (1.2 ± .6, p = .04). More girls with PA and ENP were from racial minorities (47% and 50% respectively) than girls with CPP (32%). No group differences were found for any child measure of psychological adjustment. However, mothers of girls with PA scored significantly higher than mothers of girls with ENP on one measure of depression (p = .04) and stress (p = .01). While mothers of girls with PA report increased psychological distress on some measures, no differences in psychological adjustment were found at baseline amongst the girls themselves. Whether these results will change as puberty progresses in the PA and ENP groups or with treatment of CPP is unknown. Long-term prospective studies are needed in order to further investigate psychological correlates of early puberty in girls.
Sex differences in behavior are widespread and often caused by hormonal differences between the sexes. In addition to hormones, the composition and numbers of the sex chromosomes also affect a variety of sex differences. In humans, X-chromosome genes are implicated in neurobehavioral disorders (i.e. fragile-X, autism). To investigate the role of X-chromosome genes in social behavior, we used a mouse model that has atypical sex chromosome configurations resembling Turner (45, XO) and Klinefelter syndromes (47, XXY). We examined a number of behaviors in juvenile mice. Mice with only one copy of most X-chromosome genes, regardless of gonadal sex, were less social in dyadic interaction and social preference tasks. In the elevated plus maze, mice with one X-chromosome spent less time in the distal ends of the open arms as compared to mice with two copies of X-chromosome genes. Using qRTPCR, we noted that amygdala from female mice with one X-chromosome had higher expression levels of vasopressin (Avp) as compared to mice in the other groups. Finally, in plasma from girls with Turner syndrome we detected reduced vasopressin (AVP) concentrations as compared to control patients. These novel findings link sex chromosome genes with social behavior via concentrations of AVP in brain, adding to our understanding of sex differences in neurobehavioral disorders.
Introduction: In the randomized “Toddler Turner” study, girls who received growth hormone (GH) starting at ages 9 months to 4 years (early-treated [ET] group) had marked catch-up growth and were 1.6 ± 0.6 SD taller than untreated (early-untreated [EUT]) control girls after 2 years. However, whether the early catch-up growth would result in greater near-adult height (NAH) was unknown. Therefore, this extension study examined the long-term effects of toddler-age GH treatment on height, pubertal development, and safety parameters. Methods: Toddler Turner study participants were invited to enroll in a 10-year observational extension study for annual assessments of growth, pubertal status, and safety during long-term GH treatment to NAH for both ET and EUT groups. Results: The ET group was taller than the EUT group at all time points from preschool to maturity and was significantly taller at the onset of puberty (p = 0.016), however, the difference was not significant at NAH. For the full cohort (ET + EUT combined, n = 50) mean (± SD) NAH was 151.2 ± 7.1 cm at age 15.0 ± 1.3 years. NAH standard deviation score (SDS) was within the normal range (>−2.0) for 76% of ET and 60% of EUT subjects (68% overall) and correlated strongly with height SDS at GH start (r = 0.78; p < 0.01), which in turn had a modest inverse correlation with age at GH start (i.e., height SDS declined with increasing age in untreated girls [r = −0.30; p = 0.016]). No new safety concerns arose. Conclusion: Although the ET group was taller throughout, height SDS at NAH was not significantly different between groups due to catch-down growth of ET girls during lapses in GH treatment after the Toddler study and similar long-term GH exposure overall. Early initiation of GH by age 6 years, followed by uninterrupted treatment during childhood, can prevent ongoing growth failure and enable attainment of height within the normal range during childhood, adolescence, and adulthood.