Evidence for hypermetabolism in boys with constitutional delay of growth and maturation

Approach to the Peripubertal Patient With Short Stature

CONTEXT

The assessment and treatment of children with growth retardation is increasingly complex, and due to availability of targeted genetic sequencing, an ever-expanding number of conditions impeding growth are being identified. Among endocrine-related etiologies of short stature amenable to hormonal treatment, defects in the growth hormone (GH)-insulin-like growth factor I axis remain pre-eminent, with a multiplicity of disorders causing decreased secretion or insensitivity to GH action. Sex steroids in puberty increase epiphyseal senescence and eventual growth plate closure. This is mediated mostly via estrogen receptor (ER)α in males and females, effects that can greatly limit time available for growth.

EVIDENCE ACQUISITION

Extensive literature review through PubMed and other search engines.

EVIDENCE SYNTHESIS

Therapeutic strategies to be considered in peripubertal and pubertal children with disordered growth are here discussed, including daily and weekly GH, low-dose sex steroids, gonadotropin hormone releasing hormone (GnRH) analogues in combination with GH, aromatase inhibitors (AIs) alone and in combination with GH in boys. When used for at least 2 to 3 years, GnRH analogues combined with GH can result in meaningful increases in height. AIs used with GH permit puberty to progress in boys without hindrance, selectively decreasing estrogen, and resulting in taller height. With more than 20 years of cumulative experience in clinical use of these medications, we discuss the safety profile of these treatments.

CONCLUSION

The approach of growth retardation in the peripubertal and pubertal years must consider the sex steroid milieu and the tempo of bone acceleration. Treatment of affected children in this period must be individualized.

Circulating Liver-Enriched Antimicrobial Peptide-2 Decreases during Male Puberty

Objective

Circulating levels of liver-enriched antimicrobial peptide 2 (LEAP2), a ghrelin receptor antagonist, decrease under caloric restriction and increase in obesity. The role of LEAP2 in male puberty, a phase with accelerated energy demand, is unclear.

Methods

We determined circulating LEAP2 levels in 28 boys with constitutional delay of growth and puberty (CDGP) who participated in a randomized controlled trial (NCT01797718), and were treated with letrozole (n=15) or intramuscular low-dose testosterone (T) (n=13) for 6 months. Blood sampling and dual-energy x-ray absorptiometry-measured body composition were performed at 0, 6, and 12 month visits.

Results

Serum LEAP2 levels decreased significantly during pubertal progression (0-6 mo: mean decrease -4.3 [10.3] ng/ml, p=0.036 and 0-12mo: -3.9 [9.3] ng/ml, p=0.033). Between 0 and 6 months, the changes in serum LEAP2 levels correlated positively with changes in percentage of body fat (rs=0.48, p=0.011), and negatively with growth velocity, and estradiol levels (rs=-0.43, p=0.022, rs=-0.55, p=0.003, respectively). In the T group only, the changes in serum LEAP2 correlated negatively with changes in testosterone and estradiol levels. Between 0 and 12 months, the change in LEAP2 levels correlated negatively with the change in HDL levels (rs= -0.44, p=0.022) and positively with the change in insulin (rs=0.50, p=0.009), and HOMA-IR (rs=0.51, p=0.007) levels.

Conclusions

Circulating LEAP2 levels decreased after induction of puberty reciprocally with increased growth rate and energy demand reflecting the metabolic state of the adolescent. Further, the results suggest that estradiol levels may have a permissive role in downregulating circulating LEAP2 levels.

Effect of a nutritional supplementation on growth and body composition in short and lean preadolescent boys: A randomised, double-blind, placebo-controlled study

AIM

To evaluate the effect of nutritional supplementation on height, weight and body composition in short and lean male preadolescents.

METHODS

A randomised, double-blinded, placebo-controlled trial of nutritional supplementation of short and lean prepubertal 10-14.5-year-old boys. Primary outcomes included Δheight-SDS and Δweight-SDS. Secondary outcomes included changes in body composition and BMI-SDS.

RESULTS

Of 160 boys enrolled, 126 (80%) completed 6 months' intervention. Baseline age, height-SDS, weight-SDS, BMI-SDS, body composition and dietary intake were similar in the formula and placebo groups. 'Good' formula consumers (intake of ≥50% of the recommended dose, n = 30) gained significantly more in weight-SDS, BMI-SDS, fat-free-mass and muscle mass (p < 0.05) than did 'poor' consumers (n = 35) and the placebo group (n = 61). Only in the formula group, positive dose-response correlations were found between consumption of the formula and changes in the outcome parameters examined, including Δheight-SDS (r = 0.301, p = 0.015). Boys aged >11.4 years who were 'good' formula consumers maintained their Δheight-SDS, while Δheight-SDS declined in 'poor' consumers and the placebo group of the same age (p = 0.033).

CONCLUSION

Intervention with a multi-nutrient, protein-rich formula was effective in increasing weight-SDS, fat-free-mass, muscle mass and BMI-SDS in short and lean prepubertal male adolescents. Good consumption of the formula prevented Δheight-SDS decline in the older participants.

ESR1 gene polymorphism (rs827421) as a potential genetic marker for constitutional delay of growth and puberty in Egyptian adolescents

Constitutional delay of growth and puberty (CDGP) is a variant of normal pubertal timing and progress. It is the most common form of delayed puberty in both genders. The genetic director of CDGP is ill-understood despite the positive family history result noted in those patients. The current study aimed at assessing the role of estrogen receptor 1 (ESR1) gene variant (rs827421) in Egyptian adolescents with CDGP. A cross-sectional study with follow-up part was carried out on 6760 children aged 4 to15 years. The study focused generally on children aged 13-15 years in order to evaluate the prevalence of delayed puberty in relation to all ages in general and to their peers in specific. Assessment of serum TSH, FSH, and LH was conducted on all participants, along with the measurement of serum-free testosterone for males and estradiol for females. Genotyping of ESR1 (rs827421) was done to all subjects through the use of TaqMan discrimination assay by real-time PCR. ESR1 (rs827421) GG genotype and G allele were significantly dominant among CDGP adolescents in comparison with controls (OR = 25.67 and 6.90). As regards follow-up of testicular size, AA genotype was significantly associated with increased size in the right and left testis compared to other genotypes (P = 0.021 and 0.006, respectively). Moreover, AA genotype showed significantly higher Tanner stage in both males and females in comparison with other genotypes. Serum estradiol level was significantly higher in AA genotype group than other genotypes groups. ESR1 gene polymorphism can be considered a potential genetic marker for CDGP in both sexes in a sample of Egyptian adolescents.

Differential diagnosis between constitutional delay of growth and puberty, idiopathic growth hormone deficiency and congenital hypogonadotropic hypogonadism: a clinical challenge for the pediatric endocrinologist

INTRODUCTION

Differential diagnosis between constitutional delay of growth and puberty (CDGP), partial growth hormone deficiency (pGHD) and congenital hypogonadotropic hypogonadism (cHH) may be difficult. All these conditions usually present with poor growth in pre- or peri-pubertal age and they may recur within one familial setting, constituting a highly variable, but somehow common, spectrum of pubertal delay.

EVIDENCE ACQUISITION

Narrative review of the most relevant English papers published between 1981 and march 2020 using the following search terms "constitutional delay of growth and puberty," "central hypogonadism," "priming," "growth hormone deficiency," "pituitary," "pituitary magnetic resonance imaging," with a special regard to the latest scientific acquisitions.

EVIDENCE SYNTHESIS

CDGP is by far the most prevalent entity in boys and recurs within families. pGHD is a rare, often idiopathic and transient condition, where hypostaturism presents more severely. Specificity of pGHD diagnosis is increased by priming children before growth hormone stimulation test (GHST); pituitary MRI and genetic analysis are recommended to personalize future follow-up. Diagnosing cHH may be obvious when anosmia and eunuchoid proportions concomitate. However, cHH can either overlap with pGHD in forms of multiple pituitary hormone deficiencies (MPHD) or syndromic conditions either with CDGP in family pedigrees, so endocrine workup and genetic investigations are necessary. The use of growth charts, bone age, predictors of adult height, primed GHST and low dose sex steroids (LDSS) treatment are recommended.

CONCLUSIONS

Only a step-by-step diagnostic process based on appropriate endocrine and genetic markers together with LDSS treatment can help achieving the correct diagnosis and optimizing outcomes.

Characteristic dynamics of height and weight in preschool boys with constitutional delay of growth and puberty or hypogonadotropic hypogonadism

OBJECTIVE

Constitutional delay of growth and puberty (CDGP) is a frequent variant of the normal leading to short stature and/or pubertal delay. To distinguish CDGP from hypogonadotropic hypogonadism (HH), we evaluated height, growth and weight pattern of CDGP and HH in the first 5 years of life.

DESIGN AND PATIENTS

We studied retrospectively height and weight in the first 5 years (y) of life in 54 boys with CDGP and 8 boys with HH.

RESULTS

In boys with CDGP, height-SDS decreased (change -0.94 (interquartile range [IQR] -1.69 to -0.05); P < 0.001) between birth and 2 years. BMI-SDS decreased (change -0.38 (IQR -1.21-0.16); P < 0.001) in the same time period. There were no significant changes in height-SDS or BMI-SDS between 2 years and 5 years, while height-SDS (change + 1.49 (IQR 1.02-1.95); P < 0.001) and BMI-SDS (change + 0.91 (IQR 0.12-1.69); P < 0.001) increased between pubertal and adult age. In boys with HH, height-SDS and BMI-SDS did not change significantly in the first 5 years of life. Height-SDS decreased (change -1.39 (IQR -1.96 to -0.67); P = 0.018) significantly between 5 years of life and puberty, while there were no significant changes in BMI-SDS in this time period. At pubertal age, BMI-SDS was significantly (P = 0.001) higher in boys with HH compared with boys with CDGP.

CONCLUSION

Height deflection and weight deflection in CDGP occur already during the first two years of life in contrast to HH. This different pattern of growth and weight might be helpful to distinguish CDGP from HH.

Randomized Trial of Aromatase Inhibitors, Growth Hormone, or Combination in Pubertal Boys with Idiopathic, Short Stature

CONTEXT

Growth of short children in puberty is limited by the effect of estrogen on epiphyseal fusion.

OBJECTIVES

To compare: 1) the efficacy and safety of aromatase inhibitors (AIs) vs GH vs AI/GH on increasing adult height potential in pubertal boys with severe idiopathic short stature (ISS); and 2) differences in body composition among groups.

DESIGN

Randomized three-arm open-label comparator.

SETTING

Outpatient clinical research.

PATIENTS

Seventy-six pubertal boys [mean (SE) age, 14.1 (0.1) years] with ISS [height SD score (SDS), -2.3 (0.0)].

INTERVENTION

Daily AIs (anastrozole or letrozole), GH, or AI/GH for 24-36 months.

OUTCOMES

Anthropometry, bone ages, dual x-ray absorptiometry, spine x-rays, hormones, safety labs.

RESULTS

Height gain [mean (SE)] at 24 months was: AI, +14.0 (0.8) cm; GH, +17.1 (0.9) cm; AI/GH, +18.9 (0.8) cm (P < .0006, analysis of covariance). Height SDS was: AI, -1.73 (0.12); GH, -1.43 (0.14); AI/GH, -1.25 (0.12) (P < .0012). Those treated through 36 months grew more. Regardless of treatment duration, height SDS at near-final height [n = 71; age, 17.4 (0.2) years; bone age, 15.3 (0.1) years; height achieved, ∼97.6%] was: AI, -1.4 (0.1); GH, -1.4 (0.2); AI/GH, -1.0 (0.1) (P = .06). Absolute height change was: AI, +18.2 (1.6) cm; GH, +20.6 (1.5) cm; AI/GH, +22.5 (1.4) cm (P = .01) (expected height gain at -2.0 height SDS, +13.0 cm). AI/GH had higher fat free mass accrual. Measures of bone health, safety labs, and adverse events were similar in all groups. Letrozole caused higher T and lower estradiol than anastrozole.

CONCLUSIONS

Combination therapy with AI/GH increases height potential in pubertal boys with ISS more than GH and AI alone treated for 24-36 months with a strong safety profile.

Constitutional delay of puberty: presentation and inheritance pattern in 48 familial cases

Background

The mechanism that initiates the onset of puberty is largely unknown but the age of onset is mainly under genetic control and influenced by environmental factors including nutrition. Familial forms of constitutional delay of puberty (CDP) suggest the involvement of genetic factors. The purpose of this study is to describe the presentation and the mode of inheritance of CDP in a series of familial cases.

Methods

A retrospective, single center study was carried out over 10 years on 48 probands (14 girls and 34 boys) from 48 families seen for CDP with a familial component.

Results

Of the 48 probands, 46 (96 %) had at least one affected 1^st degree relatives and 2 (4 %, 2 boys) had only 2^nd degree relatives affected.

In girls, 11 families (79 %) exhibited exclusive maternal inheritance, 1 (7 %) paternal inheritance and 2 (14 %) both maternal and paternal inheritance. In boys, 14 families (41 %) exhibited exclusive maternal inheritance, 12 (35 %) paternal inheritance and 8 (24 %) both maternal and paternal inheritance.

In the boys with bilineal inheritance, the ages at onset of puberty (16 ± 1.41 years) and at evaluation (16.05 ± 2.47 years) were higher than in those with unilineal inheritance (15.25 ± 0.35 and 15.1 ± 0.42 years respectively), but the difference was not significant.

Conclusions

In girls exclusive maternal inheritance seems to be the major mode of inheritance whereas for boys the mode of inheritance was almost equally maternal, paternal or bilineal. Clinical phenotype of boys with bilineal inheritance seems to be more severe, but the difference did not reach statistical significance, perhaps because of the small sample size. This greater severity of the phenotype in boys with bilineal inheritance is likely due to inheriting different puberty timing genes from each parent. Future research should be directed at identifying such genes.

Causes of short stature identified in children presenting at a tertiary care hospital in Multan Pakistan

OBJECTIVE

To determine the frequency of common causes of short stature in children presenting to the Children's Hospital & the Institute of Child Health, Multan.

METHODOLOGY

This cross sectional study was done in Pediatric Endocrinology department, the Children's Hospital & the Institute of Child Health, Multan, from March to September, 2011. One hundred and sixty nine children with short stature presenting to the outpatient department meeting inclusion criteria were recruited after taking an informed consent. The detailed history, physical examination including anthropometric measurements and relevant investigations were recorded. Causes of short stature (outcome variable) were recorded on a predesigned proforma for final analysis.

RESULTS

The common causes of short stature identified were; familial short stature (FSS) 36 cases (21.3%), hypothyroidism 29(17.2%), growth hormone deficiency (GHD) 18(10.7%), insulin dependent diabetes mellitus (IDDM) 16(9.5%) and constitutional delayed growth and maturation (CDGM) 11(6.5%) cases. This was followed by primary malnutrition 8(4.7%), celiac disease 6(3.6%),Turner syndrome 5(3%) cases and unknown syndromes 4(2.4%) followed by other rare causes.

CONCLUSION

Common causes of short stature identified in this study were endocrine diseases followed by normal variant short stature (NVSS), while nonendocrine causes were the least.

Kearns-Sayre syndrome presenting as isolated growth failure

Failure to thrive arises from a heterogeneous group of paediatric disorders including defects in energy metabolism such as mitochondrial diseases. Illustrating this, we describe a girl with poor growth who eluded diagnosis until she developed characteristics of Kearns-Sayre syndrome. Her history emphasises that defects of energy metabolism can present as isolated growth failure.

An approach to constitutional delay of growth and puberty

Constitutional delay of growth and puberty is a transient state of hypogonadotropic hypogonadism associated with prolongation of childhood phase of growth, delayed skeletal maturation, delayed and attenuated pubertal growth spurt, and relatively low insulin-like growth factor-1 secretion. In a considerable number of cases, the final adult height (Ht) does not reach the mid-parental or the predicted adult Ht for the individual, with some degree of disproportionately short trunk. In the pre-pubertal male, testosterone (T) replacement therapy can be used to induce pubertal development, accelerate growth and relieve the psychosocial complaints of the adolescents. However, some issues in the management are still unresolved. These include type, optimal timing, dose and duration of sex steroid treatment and the possible use of adjunctive or alternate therapy including: oxandrolone, aromatase inhibitors and human growth hormone.

Resting energy expenditure in short-stature children

It is not clear what dietary intake standards should be used for children with abnormal body size. To investigate the energy requirements of short-stature children with no underlying diseases, their resting energy requirements (REE) were measured by indirect calorimetry. The short-stature group consisted of 30 prepubertal children with short stature and with no underlying diseases (age 6y±2) and the control group consisted of 13 age-matched children with standard stature. Fasting REE and the respiration quotient (RQ) with subjects in the supine position were measured by canopy indirect calorimetry. Actual measurements and body-size-adjusted REEs were compared between the groups. Also, REE measurements were compared with the basal metabolic rate (BMR) calculated using the Dietary Reference Intakes for Japanese (Dietary Reference Intakes). REE in the control group was significantly higher than that in the short-stature group. However, body-size-adjusted REEs were significantly higher for the short-stature group. When the actual REE was compared with the calculated BMR within both the control group and the short-stature group, which was acquired using the Dietary Reference Intakes, there was no difference within the control group but the actual REE measurements were significantly higher than the calculated BMR in the short-stature group. The same pattern was seen within the short-stature group when subjects were matched for height. There were no significant differences in RQ between the two groups.

Effects of growth hormone and nutritional therapy in boys with constitutional growth delay: a randomized controlled trial

OBJECTIVE

To examine whether supplemental nutrition augments the anabolic actions of growth hormone (GH) in boys with constitutional delay of growth and maturation (CDGM).

STUDY DESIGN

We conducted a randomized, controlled trial at an outpatient clinical research center. Subjects were 20 prepubertal boys (age, 9.3 ± 1.3 years) with CDGM (height standard deviation score, -2.0 ± 0.5; bone age delay, 1.8 ± 0.8 years; body mass index standard deviation score, -1.2 ± 1.0; peak stimulated GH, 15.7 ± 7.7 ng/mL), who were randomized (n = 10/group) to 6 months observation or daily nutritional supplementation, followed by additional daily GH therapy in all for another 12 months. t tests and repeated measures analyses of variance compared energy intake, total energy expenditure (TEE), growth, hormones, and nutrition markers.

RESULTS

Energy intake was increased at 6 months within the nutrition group (P = .04), but not the observation group, and TEE was not statistically different within either group at 6 months. Addition of 6 months GH resulted in higher energy intake and TEE in the GH/nutrition group at 12 months (P < .01), but not in the GH group versus baseline. Height, weight, lean body mass, hormones, and nutrition markers increased comparably in both groups throughout 18 months.

CONCLUSION

Boys with CDGM use energy at an accelerated rate, an imbalance not overcome with added nutrition. GH therapy increases growth comparably with or without added nutrition in these patients.

Variable dietary management of methylmalonic acidemia: metabolic and energetic correlations

BACKGROUND

Isolated methylmalonic acidemia (MMA) is managed by dietary protein restriction and medical food supplementation. Resting energy expenditure (REE) can be depressed in affected individuals for undefined reasons.

OBJECTIVE

The objective was to document the spectrum of nutritional approaches used to treat patients with MMA, measure REE, and analyze the dependence of REE on body composition, biochemical, and nutritional variables.

DESIGN

Twenty-nine patients with isolated MMA (22 mut, 5 cblA, 2 cblB; 15 males, 14 females; age range: 2-35 y) underwent evaluation. REE was measured with open-circuit calorimetry and compared with predicted values by using age-appropriate equations.

RESULTS

Nutritional regimens were as follows: protein restriction with medical food (n = 17 of 29), protein restriction with medical food and supplemental isoleucine or valine (n = 5 of 29), or the use of natural protein alone for dietary needs (n = 7 of 29). Most mut patients had short stature and higher percentage fat mass compared with reference controls. Measured REE decreased to 74 ± 13.6% of predicted (P < 0.001) in the ≤ 18-y group (n = 22) and to 83 ± 11.1% (P = 0.004) in patients aged >18 y (n = 7). Linear regression modeling suggested that age (P = 0.001), creatinine clearance (P = 0.01), and height z score (P = 0.04) accounted for part of the variance of measured REE per kilogram of fat-free mass (model R² = 0.66, P < 0.0001).

CONCLUSIONS

There is wide variation in the dietary treatment of MMA. Standard predictive equations overestimate REE in this population primarily due to their altered body composition and decreased renal function. Defining actual energy needs will help optimize nutrition and protect individuals from overfeeding. This trial is registered at clinicaltrials.gov as NCT00078078.

Association of ghrelin and leptin with reproductive hormones in constitutional delay of growth and puberty

BACKGROUND

Constitutional delay of growth and puberty (CDGP) is a variation of the onset and timing of pubertal development without a defined endocrine abnormality. Recently published studies indicate that leptin and ghrelin play a role in puberty initiation and progress. They have been implicated in regulation of GnRH secretion, with ghrelin having inhibitory and leptin, facilitatory effects. We hypothesized that elevated ghrelin and reduced leptin concentrations could be implicated in altering the tempo of puberty in adolescents with CDGP. So in the current study we evaluate variations in leptin and ghrelin levels in adolescent boys with CDGP, the relationships between both hormones and reproductive hormones including LH, FSH and testosterone were also evaluated.

METHODS

The study enrolled 23 adolescent boys with CDGP and 20 healthy controls matched for age and sex. Weight, height, BMI, testicular volume, bone age, bone age delay, serum FSH, LH, testosterone, leptin and ghrelin were assessed.

RESULTS

Adolescent boys with CDGP had significantly lower leptin and higher ghrelin than normal controls. Leptin was positively correlated with BMI, bone age, testicular volume, FSH, LH and testosterone and negatively correlated with delayed bone age and ghrelin. Ghrelin was negatively correlated with BMI, bone age, testicular volume, FSH, LH and testosterone. With multiple regression analysis BMI, FSH, LH, testosterone and ghrelin remained independently correlated with leptin while BMI, LH and testosterone remained independently correlated with ghrelin.

CONCLUSION

Elevated serum ghrelin and decreased leptin concentrations and their associations with reproductive hormones may explain the sexual immaturity in adolescent boys with CDGP.

Enhanced insulin sensitivity in prepubertal children with constitutional delay of growth and development

OBJECTIVE

To test the hypothesis that prepubertal children with presumed constitutional delay of growth and development (CDGD) have enhanced insulin sensitivity and, therefore, insulin sensitivity is associated with later onset of puberty.

STUDY DESIGN

Twenty-one prepubertal children with presumed CDGD and 23 prepubertal control children, underwent a frequently sampled intravenous glucose tolerance test to evaluate insulin sensitivity and other markers of insulin, glucose, and growth regulation.

RESULTS

Children in the CDGD group were shorter and leaner than control subjects. Children with presumed CDGD were 40% more insulin sensitive (17.0 x 10(-4) min(-1)/[mU/L] versus 12.1 x 10(-4) min(-1)/[mU/L]; P = .0006) and had reduced acute insulin response, thus maintaining euglycemia (216 mU/L versus 330 mU/L; P = .02) compared with control subjects. In addition, the CDGD group had lower serum insulin-like growth factor binding protein 3 levels (3333 ng/mL versus 3775 ng/mL; P = .0004) and a trend toward lower serum insulin-like growth factor-II levels (794 ng/mL versus 911 ng/mL; P = .06).

CONCLUSION

Prepubertal children with presumed CDGD have enhanced insulin sensitivity, supporting the hypothesis that insulin sensitivity is associated with timing of puberty. It may signify long-term biological advantages with lower risk of metabolic syndrome and malignancy.

The female Gaucher patient: the impact of enzyme replacement therapy around key reproductive events (menstruation, pregnancy and menopause)

BACKGROUND

The principal manifestations of type 1 Gaucher disease (GD) (increased risk of bleeding, anaemia, splenomegaly, hepatomegaly and bone disease) are likely to affect females during reproductive events such as menarche and menstruation; fertility, pregnancy, parity, delivery and lactation; and menopause. In order to determine the optimal management of female Gaucher patients based on available data, we examine reproductive events and GD in untreated and alglucerase and/or imiglucerase-treated females.

METHODS

A panel of international clinicians experienced in the management of GD reviewed and presented evidence from peer-reviewed literature, a pharmacovigilance database on imiglucerase, and their own clinical experience to support discussions and recommendations. Nine panel members completed a 130-item-questionnaire on the outcomes of the management of female patients in their clinical practice. Results, covering menarche (137 females), menstruation (261 reports), fertility (295 females), pregnancy (416 pregnancies in 247 women) and menopause (45 women) were analysed. Data from a recent Canadian survey on 50 patients with 39 pregnancies, the imiglucerase pharmacovigilance database (100 pregnancies), and relevant literature (56 items covering 398 pregnancies in 205 women) were also reviewed.

KEY RESULTS

Menarche: May be delayed in girls with GD. Menorrhagia: Appears to be more common in GD than in the non-Gaucher population and may be ameliorated by alglucerase and/or imiglucerase treatment (menorrhagia in 67/133 (50.4%) untreated females compared with 37/128 (28.9%) treated; Mann-Whitney U test: p=0.001). Fertility: There is no evidence of decreased fertility in GD. Pregnancy: Pregnancy in GD may be complicated by haematological disease, organomegaly and bone involvement. GD diagnosis occurs frequently during pregnancy. Questionnaire results demonstrate: a reduced risk of spontaneous abortion in women treated with alglucerase and/or imiglucerase (untreated: 26/189 (13.8%); treated 1/58 (1.7%) chi(2)p=0.010); reduced risk of Gaucher-related complications during delivery (untreated 43/109 (39.4%); treated 3/46 (6.5%) chi(2)p<0.0005): and a reduced risk of Gaucher-related complications during the post partum period (untreated 15/71 (21.1%); treated 3/43 (7%) chi(2)p=0.014). There is no evidence to date of any untoward effect of alglucerase and/or imiglucerase on the fetus, or on infants breast fed by mothers receiving alglucerase and/or imiglucerase. Menopause: The impact of GD on menopause requires further study especially in relation to bone pathology.

CONCLUSIONS

On the basis of this review, GD may have an impact on reproductive events in affected women. Enzyme therapy may have benefits in reducing menorrhagia, spontaneous abortions and complications associated with delivery and the postpartum period.

Idiopathic short stature: conundrums of definition and treatment

Children with idiopathic short stature (ISS) are statistically defined by height SDS < −2 for their bone age and should be distinguished from children with familial short stature for whom height SDS corresponds to mean parental SDS and from the most common explanation for short stature referred to pediatric endocrinologists, constitutional delay in growth and maturation (CDGM), in which there is normal height for bone age and predicted normal adult stature. Low IGF-I levels reported in ISS may be the result of subtle undernutrition or reference to standards appropriate for chronologic age but not osseous maturation in CDGM inappropriately labeled as ISS. While growth hormone (GH) treatment of ISS may add 4-5 cm to adult height, meta-analysis indicates that there is no documented evidence that such treatment improves health related quality of life or psychological adaptation. Thus, the estimated cost of US$52 000/inch gained is difficult to justify. Absence of data regarding efficacy of the use of IGF-I for treatment of ISS has been noted in a recent consensus statement from the North American and European pediatric endocrinology societies. This report further emphasizes the importance of discouraging the expectation that taller stature from GH treatment will improve quality of life.

Insulin-like growth factor-I (rhIGF-I) therapy of short stature

The United States Food and Drug Administration (FDA) approved the use of subcutaneously injected rhIGF-I in late 2005 for treatment of children with severe short stature from growth hormone (GH) insensitivity due to genetic defects in the GH receptor or postreceptor mechanisms or from the development of GH inactivating antibodies. The approval was based on 15 years experience treating these rare conditions with rhIGF-I. Because of the very small numbers of children with these conditions, there has been an effort to justify and promote broader use for rhIGF-I. Attempts to identify GH unresponsiveness in children with idiopathic short stature (ISS) have yielded only a handful of patients with rare genetic disorders. IGF-I treatment for unequivocal GH insensitivity improves but does not correct growth failure, in contrast to the typical experience with GH replacement of GH deficiency. This emphasizes the importance of direct effects of GH at the growth plate, including the stimulation of maturation of cartilage precursor cells and local production of IGF-I, effects that cannot be duplicated by exogenous administration of rhIGF-I. Adverse effects testify to the more than adequate delivery of administered rhIGF-I to other tissues; these include lymphoid hyperplasia, coarsening of the facies, and increased percentage body fat. The absence of convincing evidence of GH insensitivity in a substantial number of children with ISS, the limited ability of endocrine IGF-I to restore normal growth in those with unequivocal GH unresponsiveness, the suppression of endogenous GH (and thereby, local GH effects on growth) that occurs with IGF-I administration, the risk profile, and the absence of data on efficacy in other than proven severe GH insensitivity, led the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society to conclude that rhIGF-I use is only justified in conditions approved by the FDA and that other growth promotional use should only be investigational. Nonetheless, substantial numbers of children are being treated with rhIGF-I off-label, exuberant estimates of potentially eligible patients are projected, and several uncontrolled clinical trials have been undertaken which are not based on sound preliminary data or established growth principles, and a single four-arm study begun comparing monotherapy with rhGH to combination rhGH with three dosages of rhIGF-I as a single daily injection, a means of administration of rhIGF-I that has not been tested.

Patterns of inheritance of constitutional delay of growth and puberty in families of adolescent girls and boys referred to specialist pediatric care

CONTEXT AND OBJECTIVE

Constitutional delay of growth and puberty (CDGP), more commonly observed in boys than girls, often has a familial background. We characterized the occurrence of CDGP in relatives of CDGP patients to elucidate the mechanisms influencing timing of puberty.

PARTICIPANTS AND DESIGN

We identified 492 subjects with CDGP from hospital records of two pediatric clinics in Finland; 95 male and 29 female subjects and their first-degree relatives participated. In family members, CDGP was defined by use of growth charts (growth spurt taking place 2 sd beyond the mean). One third of the families was expanded to include also second-degree relatives with an interview-based assessment of pubertal timing.

RESULTS

Of males, 80%, and of female probands, 75% had first-degree relatives with CDGP. Of all probands, 45% had one parent (unilineal families) and 32% had two parents affected. In 2% of the families, only siblings were affected. The prevalence of CDGP in male first-degree relatives was only slightly higher than in female relatives: 79 of 148 (53%) vs. 64 of 164 (39%), respectively (P=0.01); male to female ratio was 1.2:1. In 74% of extended unilineal pedigrees (17 of 23), the inheritance pattern of CDGP was consistent with autosomal dominant inheritance.

CONCLUSIONS

CDGP clusters in families. Although its inheritance likely is complex, some predisposing genetic factors may have a dominant effect. CDGP was almost as common in male and female relatives of the CDGP subjects seen at specialist care, challenging the view of a marked overall male preponderance of CDGP.

Amino-terminal propeptide of C-type natriuretic peptide and linear growth in children: effects of puberty, testosterone, and growth hormone

CONTEXT

C-type natriuretic peptide (CNP), a paracrine factor of the growth plate, plays a key role in stimulating bone growth. The amino-terminal propeptide of CNP (NTproCNP) is produced in equimolar amounts with CNP and is measurable in plasma, providing a potential biomarker for growth plate activity and, hence, linear growth.

OBJECTIVE

We explored the effects of puberty, testosterone, and GH treatment on NTproCNP levels in normal and short-statured children.

DESIGN

This was a retrospective analysis of samples obtained during previous studies.

SETTING

The study was conducted at a pediatric clinical research center.

SUBJECTS

Children with short stature due to GH deficiency, idiopathic short stature (ISS), or constitutional delay of growth and maturation (CDGM) were studied (n = 37). A cohort of normal-statured adolescent boys was also studied (n = 23).

INTERVENTIONS

Children with GH deficiency and ISS were studied before and during testosterone and/or GH treatment. Boys with CDGM and healthy controls were studied once.

MAIN OUTCOME MEASURES

The main outcomes were NTproCNP levels before and during growth-promoting therapy and during pubertal growth.

RESULTS

Children with short stature due to GH deficiency, ISS, or CDGM had comparable baseline levels of NTproCNP, and levels increased markedly in response to GH or testosterone treatment. In boys with CDGM, levels were comparable with height-matched controls but were less than those from age-matched controls. In healthy boys, NTproCNP appears to peak with the pubertal growth spurt.

CONCLUSIONS

NTproCNP levels increase during growth-promoting therapy and are increased during puberty in boys. This novel biomarker of growth may have clinical utility in the evaluation of children with short stature and for monitoring growth-promoting therapy.

The role of recombinant insulin-like growth factor I in the treatment of the short child

PURPOSE OF REVIEW

Commercial preparations of recombinant human insulin-like growth factor I became available in 2005. Off-label use has been promoted because of the paucity of patients having approved indications; I review the background and rationale for such use.

RECENT FINDINGS

Attempts to identify growth hormone unresponsiveness in children with idiopathic short stature have been nonproductive. Treatment with insulin-like growth factor I for unequivocal growth hormone insensitivity improves but does not correct growth failure, in contrast to the typical experience with growth hormone replacement of growth hormone deficiency. This emphasizes the importance of direct effects of growth hormone at the growth plate, which cannot be duplicated by administration of recombinant insulin-like growth factor I. Adverse effects testify to the more than adequate delivery of administered recombinant human insulin-like growth factor I to other tissues, including lymphoid hyperplasia, coarsening of the facies, and increased body fat.

SUMMARY

In view of the risk profile, the limited ability of endocrine insulin-like growth factor I to restore normal growth, and the suppression of endogenous growth hormone (and therefore local effects on growth) that occurs with insulin-like growth factor I administration, the use of recombinant insulin-like growth factor I should be limited to those with well-documented growth hormone unresponsiveness and severe short stature.