Gonadal function and pubertal development in patients with Silver-Russell syndrome.

STUDY QUESTION: Is gonadal function affected in males and females with Silver-Russell Syndrome (SRS)? SUMMARY ANSWER: Sertoli cell dysfunction is more common in males with SRS, with 11p15 LOM, but gonadal function seems to be unaffected in females with SRS. WHAT IS KNOWN ALREADY: Males with SRS have an increased risk for genital abnormalities such as cryptorchidism and hypospadias, which could be associated with reproductive problems in later life. In SRS females, an association has been described with Mayer-Rokitansky-Küster-Hauser syndrome, which might compromise their reproductive function. STUDY DESIGN, SIZE, DURATION: Longitudinal follow-up study, involving 154 subjects, over a time period of 20 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Thirty-one SRS patients (14 males) and 123 non-SRS patients born at same gestational age (SGA; 65 males). All received growth hormone and 27.3% received additional gonadotropin-releasing hormone analog treatment (GnRHa). MAIN RESULTS AND THE ROLE OF CHANCE: Mean age at onset of puberty was 11.5 years in SRS males versus 11.6 years in non-SRS males (P = 0.51), and 10.5 years in SRS females versus 10.7 years in non-SRS females (P = 0.50). Four of the 14 SRS males had a post-pubertal inhibin-B level below the fifth percentile compared to healthy controls, and two of them an FSH above the 95th percentile, indicating Sertoli cell dysfunction. One of them had a history of bilateral cryptorchidism and orchiopexy. All SRS females had AMH, LH and FSH levels within the reference range. Pubertal duration to Tanner stage five was similar in SRS and non-SRS. Pubertal height gain was better in SRS patients who additionally received GnRHa (P < 0.01). Mean age at menarche was 13.1 years in SRS versus 13.3 years in non-SRS (P = 0.62). One SRS female had primary amenorrhea due to Müllerian agenesis. LIMITATIONS, REASONS FOR CAUTION: As this is a rare syndrome, the SRS group had a small size. WIDER IMPLICATIONS OF THE FINDINGS: As gonadal function is not affected in females with SRS, it is likely that reproductive function is also not affected. Sertoli cell dysfunction in males with SRS could cause impaired reproductive function and should be assessed during pubertal development. STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for the study. The authors have no conflicts of interest.

New insights into factors influencing adult height in short SGA children: Results of a large multicentre growth hormone trial.

BACKGROUND: Growth hormone (GH) treatment is effective in improving adult height (AH) in short children born SGA. However, there is a wide variation in height gain, even after adjustment for predictive variables. It is therefore important to investigate new factors which can influence the response to GH. OBJECTIVE: To investigate the efficacy of GH treatment (1 mg/m(2/) day) in short SGA children on AH. To assess the relation between spontaneous catch-up growth after birth and growth during puberty on the total height gain SDS to AH. PATIENTS: Longitudinal GH trial in 170 children. RESULTS: Median age at start of GH was 7·1 years and height -3·0 SDS. AH was -1·8 SDS (TH-corrected AH -1·1 SDS) in boys and -1·9 SDS (TH-corrected AH -1·3 SDS) in girls. Spontaneous catch-up growth after birth was ≥0·5 SDS in 42% of children. In contrast to expectation, spontaneous catch-up growth was negatively correlated with total height gain SDS during GH (P = 0·009). During puberty, height SDS declined (-0·4 SDS in boys and -0·5 SDS in girls) resulting in a lower total height gain SDS than expected. Pubertal height gain was 25·5 cm in boys and 15·3 cm in girls, significantly lower compared to AGA children (P < 0·001). At onset of puberty, BA for boys and girls was moderately advanced (P = 0·02 and P < 0·001, respectively). Growth velocity was comparable to AGA children during the first two years of puberty, but thereafter significantly lower until reaching AH (P < 0·001). CONCLUSION: In contrast to our hypothesis, children with greater spontaneous catch-up growth after birth show a lower total height gain SDS during GH. Height SDS declines from mid-puberty, due to a marked early deceleration of growth velocity.

Anti-Mullerian hormone in short girls born small for gestational age and the effect of growth hormone treatment.

Background Fetal growth restriction is thought to negatively influence reproductive function in later life. Serum anti-Müllerian hormone (AMH) is a marker of the primordial follicle pool. The objectives of this study were to evaluate the effect of being born small for gestational age (SGA) on serum AMH levels and to investigate the effect of growth hormone (GH) treatment on serum AMH levels in short SGA girls. METHODS Serum AMH levels were investigated in 246 prepubertal girls aged 3-10 years: 119 untreated short SGA and 127 healthy controls. Associations between AMH levels and clinical characteristics were analysed using multiple regression analyses. In addition, we investigated the effect of GH treatment on serum AMH levels in short SGA girls. RESULTS Serum AMH levels were similar in short SGA and healthy control girls (P= 0.95). In short SGA girls, AMH levels were not significantly influenced by birth weight standard deviation score (SDS), birth length SDS and gestational age, even after adjustment for age, height SDS and body mass index (BMI) SDS at sampling, socio-economic status and maternal smoking during gestation. Serum AMH levels did not change during 4 years of GH treatment in short SGA girls (P= 0.43). ConclusionS Serum AMH levels in prepubertal short SGA girls are similar to healthy controls, indicating that the follicle pool is not compromised due to SGA birth. GH treatment has no effect on AMH levels in short SGA girls.

Long-Term Results of GH Treatment in Silver-Russell Syndrome (SRS): Do They Benefit the Same as Non-SRS Short-SGA?

CONTEXT: Silver-Russell syndrome (SRS) is a genetically heterogeneous syndrome characterized by low birth weight, severe short stature, and variable dysmorphic features. GH treatment is a registered growth-promoting therapy for short children born small for gestational age, including SRS, but there are limited data on the GH response in SRS children and on differences in response among the (epi)genetic SRS subtypes (11p15 aberrations, maternal uniparental disomy of chromosome 7 [mUPD7], and idiopathic SRS). OBJECTIVES: To compare growth and adult height between GH-treated small for gestational age children with and without SRS (non-SRS), and to analyze the difference in GH response among SRS genotypes. DESIGN AND SETTING: A longitudinal study. PARTICIPANTS: Sixty-two SRS and 227 non-SRS subjects. INTERVENTION: All subjects received GH treatment (1 mg/m(2)/d). MAIN OUTCOME MEASURES: Adult height and total height gain. RESULTS: The SRS group consisted of 31 children with 11p15 aberrations, 11 children with mUPD7, and 20 children with idiopathic SRS. At the start of GH treatment, mean (SD) height standard deviation score [SDS] was significantly lower in SRS (-3.67 [1.0]) than in non-SRS (-2.92 [0.6]; P < .001). Adult height SDS was lower in SRS (-2.17 [0.8]) than in non-SRS (-1.65 [0.8]; P = .002), but the total height gain SDS was similar. There was a trend toward a greater height gain in mUPD7 than in 11p15 (P = .12). CONCLUSION: Children with SRS have a similar height gain during GH treatment as non-SRS subjects. All (epi)genetic SRS subtypes benefit from GH treatment, with a trend toward mUPD7 and idiopathic SRS having the greatest height gain.

IGF-1 Levels, Complex Formation, and IGF Bioactivity in Growth Hormone-Treated Children With Prader-Willi Syndrome.

CONTEXT: Children with Prader-Willi syndrome (PWS) attain high-serum immunoreactive IGF-1 levels during a standard-dose GH treatment, which leads to concern, but lowering the dose deteriorates their body composition. OBJECTIVE: The objective of the study was to evaluate serum IGF-1, IGF binding protein (IGFBP)-3, and acid-labile subunit (ALS) levels, complex formation, and IGF bioactivity in GH-treated PWS children. DESIGN: This was a cross-sectional study. SETTING: The setting of the study was a Dutch PWS cohort. PARTICIPANTS: Forty GH-treated PWS children compared with 41 age- and sex-matched healthy controls participated in the study. INTERVENTIONS: Interventions included GH treatment (1.0 mg/m(2) · d = ∼0.035 mg/kg · d). MAIN OUTCOME MEASURES: Serum IGF-1, IGFBP-3, and ALS levels, complex formation, and IGF bioactivity by IGF-1 receptor kinase activation assay were measured. RESULTS: Serum IGF-1, IGFBP-3, and ALS levels and IGF-1 to IGFBP-3 ratio were significantly higher in GH-treated PWS children than in healthy controls. The 150-kDa ternary complex formation was, however, also significantly higher than in controls, indicating that most of serum IGF-1 is sequestered in the ternary 150-kDa complex with ALS and IGFBP-3. Young GH-treated PWS children [median (interquartile range) aged 5.2 (4.3-7.2) y] exhibited higher serum IGF bioactivity than controls, but no difference was observed in IGF bioactivity between older GH-treated PWS children, aged 14.9 (13.8-16.2) years, and controls. The proportion of IGF bioactivity of total serum IGF-1 was, however, lower in GH-treated PWS children than in controls. Serum immunoreactive IGF-1 levels did not correlate with IGF bioactivity in GH-treated children with PWS, in contrast to a strong positive correlation in healthy controls. CONCLUSIONS: In GH-treated PWS children, most serum IGF-1 is sequestered in the 150-kDa complex. Higher IGF bioactivity was found only in young GH-treated PWS children and not in the older ones. IGF bioactivity during GH showed a wide variation, and there was a disrupted correlation with immunoreactive IGF-1 levels, which makes immunoreactive IGF-1 levels an inappropriate indicator for GH dosing in PWS children.

Ternary complex formation and IGFBP-3 proteolytic activity during childhood: age-dependent changes.

BACKGROUND: IGF-I is mainly sequestered in a 150-kDa ternary complex with IGF binding protein (IGFBP)-3 and the acid-labile subunit. Data on complex formation and factors influencing formation have not been established. Dissociation of IGF-I from the ternary complex is in part regulated by proteolysis of IGFBP-3, which reduces its affinity for IGF-I. Short small for gestational age (SGA) children have lower IGF-I and IGFBP-3 levels compared with healthy peers. OBJECTIVE: The objective of the study was to determine complex formation in healthy normal-statured children and assess variables influencing complex formation. Second, we determined complex formation in short SGA children. DESIGN/METHODS: Complex formation was assessed using (125)I-hIGF-I column chromatography in 70 controls (40 boys), median age 10.6 years, and 40 short SGA children (25 boys), median age 8.6 years. IGFBP-3 was determined by Western immunoblotting. RESULTS: (125)I-hIGF-I complex formation showed an age-specific pattern in healthy controls. Variables positively influencing ternary complex formation were higher serum IGF-I levels compared with IGFBP-3 levels (P < .001) and lower serum IGF-II (P < .001) and IGFBP-1 levels (P < .001). In addition, a higher presence of proteolyzed IGFBP-3 negatively influenced 150-kDa complex formation (P = .006). At a young age, healthy children showed considerable IGFBP-3 proteolytic activity, which declined with aging (P < .001). IGFBP-3 proteolytic activity was negatively correlated with IGF-I levels (P < .001). Compared with healthy controls, short SGA children showed reduced IGF-I levels (-1.3 vs 0.1 SD score) and increased proteolyzed IGFBP-3 (35.1% vs 12.2%). CONCLUSION: Age-specific normative values for (125)I-hIGF-I 150-kDa ternary complex formation are presented. A decrease in IGF-I and an increase in IGF-II, IGFBP-1, and IGFBP-3 proteolytic activity associate with reduced (125)I-hIGF-I ternary complex formation. Our results suggest that in conditions in which IGF-I levels are low, such as young age and in short SGA children, IGFBP-3 proteolytic activity is increased to ensure IGF-I bioavailability.

Acid-labile subunit levels and the association with response to growth hormone treatment in short children born small for gestational age.

AIMS: To determine acid-labile subunit (ALS) levels in short small for gestational age (SGA) children and to assess the relationship between ALS levels and several clinical and laboratory characteristics. Also, to assess whether adding ALS levels to a growth prediction model might improve the long-term growth prediction. DESIGN/METHODS: ALS levels were measured in 312 short SGA children at the start of growth hormone (GH) treatment. RESULTS: Median (interquartile range) ALS of all subjects was -0.5 SDS, significantly below the 0 SDS (p < 0.001). In 34 children (11%), ALS levels were ≤-2 SDS. ALS SDS correlated significantly with height SDS (r = 0.24, p < 0.001), weight SDS (r = 0.30, p < 0.001), BMI SDS (r = 0.20, p = 0.001), IGF-I SDS (r = 0.56, p < 0.001) and IGFBP-3 SDS (r = 0.67, p < 0.001). ALS SDS was also positively correlated with fasting insulin (r = 0.41, p < 0.001) and glucose levels (r = 0.33, p < 0.001), and HOMA-IR (r = 0.35, p < 0.001). Baseline ALS levels contributed to the long-term growth prediction of GH treatment (5%, p < 0.001). CONCLUSION: Short SGA children tend to have lower ALS levels compared to controls, albeit less reduced than IGF-I and IGFBP-3 levels. Our data suggest that ALS may be involved in glucose homeostasis. Determination of ALS levels before the start of GH treatment in short SGA children contributes moderately to a more accurate prediction of the growth response to GH treatment.