Thyroid function in preterm infants 27-29 weeks of gestational age during the first four months of life: results from a prospective study comprising 80 preterm infants

AIM

Assessment of thyroid function in preterm neonates (PTN) 27-29 weeks of gestational age.

PATIENTS AND METHODS

80 PTN, gestational age 27 weeks in 24, 28 weeks in 28, and 29 weeks in 28. Neonates were classified as healthy (n=17) or sick (n=63). Measurement of serum TSH, free T4, T4, T3 and rT3 in the mother and in the cord at the time of delivery, and in the infant at 1 hour, 24 hours, 1 week, 3 weeks, and 2 and 4 months of postnatal age.

RESULTS

In healthy and sick preterms, TSH values peaked at 1 hour and decreased thereafter. Healthy PTN presented a peak in free T4 values at 24 hours that was not observed in sick neonates. Sick PTN had a lower TSH peak and lower free T4 values at 24 hours and 1 week than healthy ones (p < 0.05). Healthy PTN 27-29 weeks had lower TSH peak at 1 hour and lower free T4, T3 and T4 values during the first 2 months than healthy PTN 30-35 weeks (PTN30-35w) previously evaluated (p < 0.05). However, at all postnatal times healthy preterms had free T4 values above -2 SD of the mean values of healthy PTN30-35w. A wide range of free T4 values was observed in the sick group. Free T4 values above -2 SD of the mean values of healthy PTN30-35w were detected in a high proportion of sick PTN (58.3% at 24 hours, 73.5% at 1 week, 93.9% at 3 weeks, 85.1% at 2 months and 100% at 4 months).

CONCLUSIONS

Prematurity and disease influence thyroid function, and consequently thyroid function should be individually assessed in preterms 27-29 weeks of gestation during the first 2 months of life.

A lesser postprandial suppression of plasma ghrelin in Prader-Willi syndrome is associated with low fasting and a blunted postprandial PYY response

OBJECTIVE

Ghrelin and polipeptide YY (PYY) are involved in the regulation of food intake. We evaluated these two peptides and their possible relationship in adult patients with Prader-Willi syndrome (PWS).

PATIENTS

Seven patients with PWS, 16 age-sex-BMI matched obese and 42 age-sex matched lean subjects.

DESIGN AND MEASUREMENTS

Fasting plasma PYY and ghrelin levels were measured in all subjects and, postprandially until 6 h, in seven matched subjects of each group.

RESULTS

Fasting ghrelin levels were higher in PWS than in the other two groups. Fasting PYY levels were lower in patients with PWS than in lean subjects but similar to those in obese subjects. The postprandial decrease in ghrelin concentrations was lower in PWS as compared to the other two groups and therefore the 6-h-postprandial area under the curve (AUC) for ghrelin was higher in PWS than in obese subjects. PYY response after the meal was blunted in patients with PWS, but not in the other two groups that showed a peak at 60 min The AUC for PYY was lower in PWS as compared to the other two groups. Fasting PYY levels correlated negatively with fasting ghrelin levels and with ghrelin AUC and they were the only predictor for ghrelin AUC (beta = -0.464, P = 0.034). The increase in PYY correlated negatively with the decrease in ghrelin at times 60 min and 120 min in PWS.

CONCLUSIONS

In PWS, the low decrease in postprandial ghrelin levels could be related to the low fasting PYY concentrations and their blunted postprandial response.

Hypoglycaemia-Insulin Test: Discordant Growth Hormone and Cortisol Response in Paediatric Patients Regarding Recovery from Hypoglycaemia with or without Oral Glucose Solution

BACKGROUND

Hypoglycaemia-insulin test (HIT) is the 'gold standard' for the diagnosis of adrenal-pituitary-hypothalamic axis disorders. Controversy exists on the convenience of recovery from an insulin-induced hypoglycaemia since this test is not risk-free.

OBJECTIVE

To ascertain whether recovery from insulin-induced hypoglycaemia with an oral glucose solution produces a different response of growth hormone (GH) and cortisol at different times of the study compared with spontaneous recovery from hypoglycaemia.

PATIENTS AND METHODS

Prospective study of 100 children and adolescents with growth delay who underwent an HIT. Patients were consecutively assigned to two groups of 50. In one group recovery from hypoglycaemia occurred spontaneously and in the other recovery was achieved with an oral glucose solution (20 g of glucose) when glycaemia was under 30 mg/dl. The two groups did not differ in age, sex, pubertal status, weight, height and IGF-I levels.

RESULTS

The response of GH at 30, 60, 90 and 120 min and cortisol at 10, 60, 90 and 120 min was lower and statistically significant in patients with recovery from hypoglycaemia with oral glucose solution. GH deficiency was diagnosed more frequently in patients recovered with glucose solutions (94%) compared to those with spontaneous recovery (68%).

CONCLUSIONS

Oral glucose solution administration when glycaemia was under 30 mg/dl in HIT produced a lower GH and cortisol response to insulin stimulus and a greater frequency of GH deficit diagnosis.

Functional study of a novel single deletion in the TITF1/NKX2.1 homeobox gene that produces congenital hypothyroidism and benign chorea but not pulmonary distress

CONTEXT

We studied two sisters with congenital hypothyroidism and choreoathetosis but not respiratory distress.

OBJECTIVE

The aim of this study was to establish the genetic defect that causes this phenotype and study the molecular mechanisms of the pathology by means of functional analysis.

DESIGN

Sequencing of DNA, expression vectors generation, EMSAs, transfections experiments as well as bioinformatics analysis were performed.

RESULTS

We found a new single deletion (825delC) in one allele of the TITF1/NKX2.1 gene. The mutation located in the C-terminal domain generates a nonsense thyroid transcription factor 1 (TTF1) protein, with 22 amino less and rich in positive charges. This protein shows diminished binding to DNA, does not interfere with wild-type (wt) TTF1 binding, and fails to activate reporter genes harboring the thyroglobulin (Tg), thyroperoxidase (TPO), or surfactant protein B (SP-B) promoters. In addition, the mutant (mut) protein has a dominant-negative effect on the transcriptional activity of wt TTF1 in a promoter-specific manner, inhibiting the transcription of Tg and TPO but not of SP-B. Using a Gal4 reporter system, we demonstrate that the mut protein is not transcriptionally active and does not likely compete with the wild type for coactivators. Interestingly, the mut protein impairs the wt capacity to synergize with paired box 8 (PAX8). This cooperation is necessary for Tg and TPO transcription but dispensable for SP-B expression.

CONCLUSION

These results are concordant with the phenotype of the two sisters studied and demonstrate a differential role for TTF1 in the different tissues in which it is expressed.

Postprandial Adiponectin Levels Are Unlikely to Contribute to the Pathogenesis of Obesity in Prader-Willi Syndrome

AIM

To investigate fasting and postprandial adiponectin levels in PWS patients as compared to obese and lean subjects and whether they could contribute to the pathogenesis of obesity in this syndrome.

METHODS

We studied 7 patients with PWS, 16 obese patients and 42 lean subjects for the fasting study. From this group, we evaluated 7 patients with PWS, 7 age-sex-BMI-matched obese non-PWS patients and 7 age-sex-matched lean subjects before and after the administration of 3,139.5 kJ (750 kcal) of a standard liquid meal (53.2% carbohydrate, 30% fat, 16.7% protein) after an overnight fast. Blood samples were obtained every 15 min for the first hour and every 30 min thereafter until 6 h. Adiponectin, IGF-I, glucose, triglycerides, cholesterol, and insulin were measured.

RESULTS

Fasting plasma adiponectin levels were lower in PWS than in lean subjects (5.24+/-2.56 vs. 8.28+/-4.63 microg/ml, p=0.041) but higher than in obese patients (4.01+/-1.27 microg/ml, p=0.047). After the meal, adiponectin concentrations mildly decreased in PWS at time point 240 min, while in obese and lean subjects no changes were observed. However, 6-hour postprandial AUC for adiponectin was similar in all three groups.

CONCLUSION

Fasting adiponectin levels are low in PWS, but they are so mildly modulated postprandially that these changes do not seem significant for the pathogenesis of obesity in this syndrome.

Intolerancia a la glucosa en niños y adolescentes obesos

BACKGROUND AND OBJECTIVE

The rise in the prevalence of glucose intolerance and type 2 diabetes mellitus in childhood and adolescence in recent decades appears to be closely related to the increase in the incidence of obesity in developed countries. We decided to establish the frequency of glucose intolerance and type 2 diabetes mellitus in a population of obese children and adolescents evaluated at our hospital.

PATIENTS AND METHOD

Prospective study of 145 obese patients (60 boys: BMI 29.5 (4.9), BMI z score 4.4 (1.7); and 85 girls: BMI 28.8 (4.6), BMI z score 3.8 (1.4); age range: (4-18 years) who underwent an oral glucose tolerance test (OGTT) between 1998 and 2003. OGTT results were evaluated according to WHO criteria. Insulin secretion and sensitivity parameters (HOMA, QUICKI, area under the curve for glycemia, area under the curve for insulin and insulinogenic index) were also calculated.

RESULTS

The frequency of glucose intolerance in the whole population was 19.2%. However, this prevalence varied with age and maturation stage (prepuberty 7.0%, puberty 28.2% and postpuberty 26.5%), and with the obesity degree (BMI z-score between +2 and +3: 8.9%; between +3 and +4: 21.9% and higher than +4: 25%). No type 2 diabetes mellitus cases were observed.

CONCLUSIONS

Obese children and adolescents display an elevated incidence of glucose intolerance which seems to be related to the degree of adiposity.

Circulating ghrelin in thyroid dysfunction is related to insulin resistance and not to hunger, food intake or anthropometric changes

OBJECTIVE

Ghrelin is a gastric peptide that plays a role in appetite stimulation, energy balance and possibly in insulin resistance. Hyperthyroidism is a situation where negative energy balance and insulin resistance coexist, while in hypothyroidism a positive energy balance and normal insulin sensitivity predominate. We investigated ghrelin levels and their relationship with hunger, food intake and both anthropometric and insulin resistance parameters in patients with thyroid dysfunction.

DESIGN AND METHODS

We studied 24 hyperthyroid and 17 hypothyroid patients before and after normalisation of thyroid hormone levels and their respective body mass index (BMI)-matched control group. We measured plasma ghrelin levels, homeostasis model assessment of insulin resistance (HOMA-IR) index, a hunger score, mean three-day calorie intake and anthropometric parameters.

RESULTS

In hyperthyroidism, HOMA-IR index was higher (3.21 +/- 0.60 vs 1.67 +/- 0.15 mMmU/l; P = 0.014, t test for independent data) and ghrelin levels were lower (463.6 +/- 36.4 vs 561.1 +/- 32.1 pg/ml; P = 0.041, Mann-Whitney U-test) than in its control group and both normalised after treatment (HOMA-IR: 2.28 +/- 0.38 mMmU/l; P = 0.106, t test for independent data, and ghrelin: 539.7 +/- 45.4 pg/ml; P = 0.549, Mann-Whitney U-test). Glucose, as a component of HOMA-IR index was the only predictor for ghrelin levels (beta = -0.415, P = 0.044, stepwise multiple regression analysis). In hypothyroidism, HOMA-IR index and ghrelin levels were similar to those in its control group both before and after treatment. In both thyroid dysfunction states, no correlations were observed between changes in ghrelin levels and in free T4, free T3, anthropometric parameters, total calorie intake and hunger score.

CONCLUSIONS

In thyroid dysfunction states, ghrelin levels seemed to be in relation to insulin resistance and not to energy balance and food intake regulation, as seen in other physiological and pathological states.

Thyroid function in seventy-five healthy preterm infants thirty to thirty-five weeks of gestational age: a prospective and longitudinal study during the first year of life

Thyroid function was evaluated in 75 healthy preterm infants, 30-35 weeks of gestational age. Serum thyrotropin (TSH), thyroxine (T(4)), triiodothyronine (T(3)), free T(4) (immunochemoluminescence) and reverse triiodothyronine (rT(3)) (radioimmunoassay) were measured in the mother and in the cord at delivery and in the preterm infants at 1 hour, 24 hours, 1 week, 3 weeks, 2 months, 4 months, 6 months, and 12 months of postnatal age. These values were compared to those of healthy full-term infants of the same postnatal age (22 at 24 hours from our hospital and from previously reported data at others times). Mean 24-hour TSH values were significantly lower (p < 0.001) in preterm than in full-term infant populations (12.38 +/- 6.13 microIU/mL versus 22.02 +/- 13.28 microIU/mL); however, all TSH values of preterm infants were in the range of the full-term values. Mean 24-hour free T(4) values were similar in preterm and full-term infants (1.88 +/- 0.46 ng/dL versus 2.01 +/- 0.54 ng/dL) and all preterm infants had free T(4) values within the range of those of full-term infants at 24 hours. Mean T(4) and T(3) values were significantly lower in preterm than in full-term neonates at 1 hour and 24 hours of age. Mean 24-hour rT(3) values were significantly higher in preterm than in full-term newborns. From 1 week onwards, all thyroid function values were in the same range in both populations. In conclusion, individual thyroid function was similar in healthy preterms and full-terms from the first 24 hours of life. Normative data in preterm infants during the first year of life applying the latest luminescence techniques currently used worldwide are reported.

Opposing influences of prenatal and postnatal weight gain on adrenarche in normal boys and girls

Associations between low birth weight and higher adrenal androgen secretion before puberty have yet only been reported in case-control studies in girls. We examined the influence of birth weight and early postnatal weight gain on overnight-fasting adrenal androgen and cortisol levels in 770 children from a large normal United Kingdom birth cohort at age 8 yr. In univariate analyses, adrenal androgen levels were inversely related to birth weight sd score in each sex [dehydroepiandrosterone sulfate in boys: regression coefficient (B) = -2.5 microg/dl/SD; 95% confidence interval (CI), -4.7 to -0.2; in girls: B = -3.8 microg/dl/SD; 95% CI, -6.2 to -1.4; androstenedione in boys: B = -0.15 nmol/liter/sd, 95% CI, -0.25 to -0.6; in girls: B = -0.13 nmol/liter/SD; 95% CI, -0.24 to -0.02). In multivariate analyses, both lower birth weight and larger current body weight predicted higher adrenal androgen levels (P < 0.005 for all comparisons). Allowing for current weight, children who showed rapid postnatal weight gain between 0 and 3 yr had higher dehydroepiandrosterone sulfate (P = 0.002) and androstenedione (P = 0.004) levels at 8 yr. In contrast, cortisol levels were unrelated to birth weight or current body size. In summary, the relationship between lower birth weight and higher childhood adrenal androgen levels was continuous throughout the range of normal birth weights, and was similar in boys and girls. Adrenal androgen levels were highest in small infants who gained weight rapidly during early childhood. We suggest that higher adrenal androgen secretion could contribute to links between early growth and adult disease risks, possibly by enhancing insulin resistance and central fat deposition.

Fasting insulin sensitivity and post-oral glucose hyperinsulinaemia related to cardiovascular risk factors in adolescents with precocious pubarche

OBJECTIVE

Adolescents and young women with a history of precocious pubarche (PP, appearance of pubic hair before 8 years) exhibit hyperlipidaemia, and ovarian hyperandrogenism, indicating increased risk of coronary heart disease in the long term. The aim of this study was to determine the relative contribution of fasting insulin sensitivity, and post oral glucose tolerance test (OGTT) measures of insulin secretion to metabolic risk markers of adult disease.

PATIENTS AND DESIGN

We have analysed data from 51 young women presenting with isolated PP (age range, 5.9-19.0 years) in early, mid and late puberty and 68 puberty-matched controls (age range, 6.2-16.8 years). Body composition data from a further 67 girls with PP are also presented.

MEASUREMENTS

The homeostasis model of assessment insulin sensitivity index (HOMA Si) based on fasting glucose and insulin measurements and MSI120 based on insulin levels over the first 120 min following standard oral glucose load were selected as measures of fasting insulin sensitivity and 0-120-min insulinaemia, respectively. ISI30 was used as an index of insulin secretion 30 min following oral glucose load.

RESULTS

The physiological decrease in fasting insulin sensitivity, 30-min insulin secretion and 0-120-min insulinaemia during puberty were exaggerated in PP girls. The relationship between fasting insulin sensitivity and 0-120-min insulinaemia was similar in PP girls and in controls but at each level of fasting insulin sensitivity the PP girls had a higher level of insulin secretion in response to an oral glucose load (P < 0.001). Fasting insulin sensitivity and 0-120 minute insulinaemia but not 30-min insulin secretion were strongly related to known cardiovascular risk factors. In a multivariate model incorporating fasting insulin sensitivity, 0-120-min insulinaemia, pubertal stage and body mass index (BMI) SDS as covariates, 0-120-min insulinaemia was strongly associated with elevated free androgen index, total cholesterol and truncal fat mass (P < 0.001) whereas fasting insulin sensitivity was associated only with reduced free androgen index (P < 0.02).

CONCLUSIONS

Chronic exposure to insulin as reflected by 0-120 min hyperinsulinaemia, rather than 30 min insulin secretion, or fasting insulin senstivity, was most closely related cardiovascular disease risk in girls with PP.

Hypergonadotrophinaemia with reduced uterine and ovarian size in women born small-for-gestational-age

BACKGROUND

Fetal growth restraint has been associated with FSH hypersecretion in early infancy and in early post-menarche, and with reduced uterine and ovarian size in adolescence. It is unknown whether these reproductive anomalies persist, respectively, into late infancy and into the reproductive age range.

METHODS

We report follow-up findings in two age groups of girls. A cohort of infants [n=26; n=10 born appropriate-for-gestational-age (AGA) and n=16 born small-for-gestational-age (SGA)], who had been studied at the age of approximately 4 months, was assessed again at the age of 12 months. A cohort of teenagers (n=28), who had been studied at the age of approximately 14 years, was assessed again at the age of approximately 18 years; this group was complemented by a transversal cohort of similar age (n=19) for a total of 47 young women (n=27 AGA; n=20 SGA). In infants, only serum FSH was measured; adolescents underwent endocrine-metabolic screening, ultrasound assessment of uterine-ovarian size, and evaluation of body composition by dual X-ray absorptiometry.

RESULTS

Serum FSH levels were higher in SGA than AGA infant girls at 4 and 12 months, and higher in SGA than AGA adolescents at 14 and 18 years (all P<0.01). Longitudinal ultrasound assessments disclosed a late-adolescent increment of uterine size that was less obvious in SGA than AGA girls. In contrast, ovarian volume remained stable in both subgroups. Compilation of longitudinal and transversal results at 18 years of age corroborated the persistent reduction in the uterine size of SGA girls (by approximately 20%; P<0.005) and in their ovarian volume (by approximately 40%; P<0.0001); moreover, SGA girls displayed not only a persistent elevation of FSH (by approximately 50%; P<0.001), but also a rise of LH and fasting insulin, as well as an excess of abdominal fat (all P<0.01).

CONCLUSIONS

The gynaecology of young women born SGA was found to be characterized by hypergonadotrophinaemia and by a reduced uterine and ovarian size.

Anovulation in eumenorrheic, nonobese adolescent girls born small for gestational age: insulin sensitization induces ovulation, increases lean body mass, and reduces abdominal fat excess, dyslipidemia, and subclinical hyperandrogenism

Adolescent girls born small for gestational age (SGA) are at risk for anovulation, hyperinsulinism, subclinical hyperandrogenism, dyslipidemia, and central adiposity. Hyperinsulinemic insulin resistance has been proposed as a key pathogenetic factor underpinning these associations. We have tested this hypothesis in an intervention study by assessing the effects of insulin sensitization (metformin treatment, 850 mg/d for 3 months) in eumenorrheic, nonobese, anovulatory SGA adolescents [n = 13; mean birth weight, 2.3 kg; age, 15 yr; body mass index (BMI), 20.5 kg/m(2); >or=3 yr post-menarche] who were in a steady state (over approximately 6 months) for BMI, hyperinsulinism, subclinical hyperandrogenism, and dyslipidemia, and who presented a deficit of lean body mass and an excess of (truncal and abdominal) fat mass. Metformin treatment was accompanied by a drop in fasting insulin and serum androgens and by a less atherogenic lipid profile (all P <or= 0.01). After 3 months on metformin, all identified aberrations in body composition were attenuated, the most marked changes (P < 0.0001) being a reduction of the excess in abdominal fat and of the deficit in lean body mass; BMI remained unaltered. Finally, 6 of 13 girls became ovulatory after about 6 wk on metformin, and 9 of 13 (69%) ovulated within 11 wk on metformin. In conclusion, these observations corroborate the notion that anovulation, an excess of abdominal fat mass, and a deficit of lean mass in nonobese SGA adolescents are essentially underpinned by hyperinsulinemic insulin resistance, and that sensitization to insulin is an effective approach to correct these abnormalities and, conceivably, to prevent them.

Increased frequency of the G972R variant of the insulin receptor substrate-1 (irs-1) gene among girls with a history of precocious pubarche

To test the hypothesis that lower sex hormone-binding globulin (SHBG) concentrations are associated with heterozygosity for the G972R variant of the IRS-1 gene among adolescent girls with a history of precocious pubarche (PP) and hyperinsulinemic ovarian hyperandrogenism.Association study. Academic research environment. Adolescent girls with a history of PP and healthy adolescent female control subjects. Determine body mass index; measure serum androgen, insulin-like growth factor (IGF)-binding protein 1, lipids, IGF-1, and SHBG concentrations; perform glucose tolerance tests; and assay for G972R variant of the IRS-1 gene. Serum androgen, IGFBP-1, and SHBG concentrations; IRS-1 genotypes.Twenty-five of 54 (45%) girls with a history of PP developed hyperinsulinemic ovarian hyperandrogenism at adolescence. Frequency of heterozygosity for G972 was 31% among girls with a history of PP, 40% among girls with hyperinsulinemic ovarian hyperandrogenism, and 19% among healthy control subjects. Sex hormone-binding globulin concentrations were lower among girls heterozygous for G972R variant. Predictors of progression from PP to hyperinsulinemic ovarian hyperandrogenism included chronological age, insulin, low-density lipoprotein cholesterol, and IGFBP-1 concentrations. The low mean SHBG concentration found among G972R carriers suggests that this variant may be a minor locus associated with development of hyperinsulinemic insulin resistance and ovarian androgen excess in girls with a history of PP.

Molecular defects of the CYP21 gene in Spanish girls with isolated precocious pubarche

OBJECTIVE

To determine the frequency of mutant alleles in the CYP21 gene in Spanish girls presenting with precocious pubarche (PP) and to assess the relationships between genotype and endocrine-metabolic variables.

DESIGN

Fifty-three unrelated girls with a history of PP (14 prepubertal, 8 pubertal and 31 postmenarcheal) and 35 controls were studied.

METHODS

Genomic DNA was extracted from peripheral blood leukocytes. After selection against the pseudogen, an allele-specific PCR was used to identify 14 known mutations in the CYP21 gene. The mutations studied were Pro30Leu, splice intron 2, Ilel72Asn, Cluster E(6), Glyl92Ser, Ins T, GT-CT, Gln318-stop, Arg357Trp, Trp406-stop, Pro453Ser, Arg483Pro, Arg483 frameshift and Val281Leu. A standard 2-h oral glucose tolerance test was performed in all PP girls. Ovarian 17-hydroxyprogesterone (17-OHP) responses to gonadotrophin-releasing hormone-agonist stimulation was assessed in postmenarcheal PP girls.

RESULTS

Thirteen PP girls and eight control girls were heterozygous for one of the mutations studied. The frequency of the carrier status was 25% and 23% in the PP and control groups respectively. Severe mutations were found in 33% of the carrier girls. Serum 17-OHP responses to ACTH stimulation were similar in carriers and non-carriers (351+/-65 vs 334+/-22 ng/dl). The presence of ovarian hyperandrogenism and/or hyperinsulinism was also not related to the carrier status.

CONCLUSION

The incidence of molecular defects in the CYP21 gene in the present study was comparable in the PP and control groups. We found no relationship between the presence of carrier status and endocrine-metabolic abnormalities. Prospective studies of larger cohorts of PP girls are needed to ascertain the long-term clinical relevance of CYP21 heterozygosity.

Hyperinsulinemia in pre- and post-pubertal children born small for gestational age

BACKGROUND

Reduced fetal growth is a potential risk factor for development of metabolic abnormalities in later life. The relationship between low birthweight and impaired glucose tolerance, type 2 diabetes and insulin resistance in adulthood has been well documented.

PURPOSE

Assuming that fetal undernutrition is associated with insulin resistance in middle age, we elected to study whether this process may already be present in young adults and adolescents born small for gestational age (SGA).

SUBJECTS AND METHODS

Children born in Vall d'Hebron Hospital Infantil, Barcelona, between 1986 and 1989 and between 1978 and 1983 with birthweights below the third centile for the local standard values, were invited to participate in the present study. Of those, 51 (22 girls and 29 boys) were pre-pubertal with 9.4 +/- 0.2 years of age and 49 (29 girls and 20 boys ) were post-pubertal, with 17.3 +/- 0.3 years of age. All patients underwent a standard, 2-hour oral glucose tolerance test. Insulin and glucose responses were compared with our previously published data in control children with normal birthweight.

RESULTS

The insulin response at 30 min after glucose load was significantly higher (p < 0.001) in pre- and post-pubertal girls and boys formerly SGA than in controls. In addition, the girls also had a higher insulin response at 60 and 120 min. Mean serum insulin (MSI), the area under the insulin curve during the glucose challenge, was statistically increased in pre- and post-pubertal boys and girls born SGA when compared to controls.

CONCLUSION

The presence of high insulin levels after an oral glucose challenge in children and adolescents born SGA might be considered as an early marker of subsequent insulin resistance in adulthood. Furthermore, our population offers the opportunity to study the natural course of hyperinsulinemia and its outcome. Follow-up of this cohort may be helpful in distinguishing a subset of young children and adolescents in whom therapeutic intervention could be done.

Reduced ovulation rate in adolescent girls born small for gestational age

FSH and insulin are key hormones involved in spontaneous ovulation. Adolescent girls born small for gestational age (SGA) are at risk for FSH and insulin resistance. We have assessed whether ovulation rate is reduced in SGA girls. Ovulatory function was assessed by weekly filter paper progesterone measurements, obtained by finger-stick auto-sampling for 3 consecutive months in matched populations of asymptomatic, nonobese girls (mean age, 15.5 yr; > or =3 yr postmenarche) who were either born with an appropriate weight for gestational age (AGA; n = 24; mean birthweight, 3.3 kg) or born small for gestational age (SGA; n = 25; mean birthweight, 2.3 kg). The prevalence of anovulation was higher among SGA than AGA girls (40% vs. 4%; P = 0.002). Moreover, in the relatively small fraction of ovulating SGA girls, the ovulation rate was lower than in AGA adolescents (average number of ovulations during the study, 1.4 vs. 1.9; P < 0.01). In conclusion, the endocrine correlates of prenatal growth restraint are herewith extended to include oligo-ovulation and anovulation in adolescence. It remains to be verified whether this SGA-related phenomenon persists into the reproductive age range. If it does, then fetal growth restraint may prove to be one of the enigmatic components underpinning hitherto unexplained female subfertility.

Plasminogen activator inhibitor-1 in girls with precocious pubarche: a premenarcheal marker for polycystic ovary syndrome?

In both obese and nonobese women, polycystic ovary syndrome (PCOS) is essentially a disorder of hyperinsulinemic insulin resistance, and it may be heralded by precocious pubarche (PP; appearance of pubic hair in girls aged <8 y). The risk of progression from PP to PCOS is related to low birth weight, but there are no early biochemical markers of this risk. As increased plasminogen activator-inhibitor type 1 (PAI-1) activity (act) is an early marker of cardiovascular risk in PCOS, we have sought abnormalities in young girls with PP. In 33 young PP girls (age range 6-11 y), PAI-1-act was increased (mean + SEM: 15.6 +/- 1.5 IU/mL) compared with age-, sex-, and pubertal stage-matched controls (n = 13, 10.7 +/- 1.9, p < 0.05). PAI-1-act levels were inversely related to birth weight SD score (r = -0.33, p < 0.05), and PAI-1-act levels were therefore higher in PP girls with low birth weights (n = 14, 19.5 +/- 2.5 IU/mL) than normal birth weights (n = 19, 12.8 +/- 1.5, p < 0.01). During longitudinal observation in 10 PP girls (mean time interval 2.7 y), PAI-1-act levels in early puberty were positively related to postmenarcheal insulin levels (mean serum insulin SDS postoral glucose, r = 0.65, p < 0.05), and showed a similar relationship to postmenarcheal testosterone levels (r = 0.61, p = 0.06). Together with low birth weight, increased plasma PAI-1-act levels in early pubertal PP girls may indicate those girls with greater risk of developing hyperinsulinemic-hyperandrogenism features of PCOS.

Insulin gene variable number of tandem repeat genotype and the low birth weight, precocious pubarche, and hyperinsulinism sequence

Low birth weight associations with hyperinsulinemia and other adulthood disease risk factors have been described in several cohorts, including girls who present with precocious pubarche (pubic hair <8 yr). We hypothesized that these associations might be influenced by the insulin gene (INS) variable number of tandem repeat (VNTR), a common polymorphism related to INS transcription levels. In 141 Caucasian girls, who presented with precocious pubarche, hyperinsulinemia was assessed from mean insulin levels during an oral glucose load (MSI), and insulin sensitivity was determined from fasting glucose and insulin levels. Fasting blood lipid profiles were also measured. DNA was genotyped for INS VNTR allele class (I or III) in precocious pubarche girls and in 140 age- and body mass index-matched control girls. INS VNTR genotype distribution was similar in precocious pubarche and control girls. However among precocious pubarche girls, INS VNTR genotype was related to the severity of phenotype; I/I and I/III genotypes had lower birth weights (P < 0.01), higher MSI (P < 0.005), and lower insulin sensitivity (P < 0.005) than III/III girls. In precocious pubarche girls, birth weight was also inversely related to MSI (r = -0.29; P < 0.0005), total cholesterol (r = -0.38; P < 0.0005), and low density lipoprotein cholesterol (r = -0.44; P < 0.0005). Using logistic regression, additive adverse effects of I/* genotype and low birth weight were seen on MSI (P = 0.03 and P = 0.004, respectively) and total cholesterol levels (P = 0.01 and P < 0.0001). In summary, in girls who presented with precocious pubarche, hyperinsulinemia and dyslipidemia were related to both low birth weight and INS VNTR class I alleles. A similar interaction between genotype and intrauterine growth restraint may underlie other reported links between low birth weight and adulthood disease risks.

Polycystic ovary syndrome after precocious pubarche: ontogeny of the low-birthweight effect

OBJECTIVE

Young girls with precocious pubarche (PP) are at increased risk of developing polycystic ovary syndrome (PCOS), including hyperinsulinism, dyslipidaemia and ovarian hyperandrogenism, particularly if PP itself was preceded by a low birthweight. Resistance to insulin is thought to be a key factor in the pathogenesis of this sequence. We aimed to elucidate the peripubertal ontogeny of the low birthweight effect on hyperinsulinism, dyslipidaemia and ovarian dysfunction after PP.

PATIENTS AND DESIGN

We obtained fully longitudinal data from 51 girls with a history of PP and compared normal-birthweight (n = 26) with low-birthweight (n = 25) girls (birthweight SD score 0.0 +/- 0-2 vs. - 2.4 +/- 0.2) for measurements obtained at diagnosis of PP (mean age 7.0 years), in early puberty (10.4 years) and after menarche (14.3 years).

MEASUREMENTS

Fasting serum lipids and lipoproteins, together with insulin responses to an oral glucose load, were assessed at diagnosis of PP, in early puberty and after menarche; serum gonadotropins were measured in early puberty and after menarche; ovarian function was examined postmenarche.

RESULTS

Comparisons of endocrine-metabolic results between normal- and low-birthweight PP girls showed no detectable differences before puberty. The hypertriglyceridaemia and elevated LDL-cholesterol levels characterizing low-birthweight PP girls became detectable by early puberty; reduced insulin sensitivity was not evident until postmenarche, when the tendency to ovarian dysfunction also became obvious. Body mass indices of normal- and low-birthweight subgroups were identical in early puberty and postmenarche.

CONCLUSIONS

These longitudinal data show that, in PP girls, the endocrine-metabolic risk conferred by prenatal growth restraint is not readily detectable until puberty or postmenarche, and is not attributable to a higher body mass index.

Increased bone mineral density and serum leptin in non-obese girls with precocious pubarche: relation to low birthweight and hyperinsulinism

BACKGROUND

Hyperinsulinism and hyperandrogenism have the capacity to increase bone mineral density (BMD) and serum leptin, independently of body fat mass. We therefore assessed lumbar BMD and serum leptin in girls with the sequence of a low birthweight and precocious pubarche (PP) in childhood, in whom hyperinsulinism and hyperandrogenism have been described.

METHODS

Fifty-two non-obese PP girls were studied (age range 6.9-14.9 years). Serum leptin was also measured in 42 control girls, matched for age, body mass index and pubertal stage.

RESULTS

BMD SDS, measured by dual-energy X-ray absorptiometry, was elevated in PP girls compared to the population reference (0.39 +/- 0.18 SDS; p = 0.03) and bone age, assessed from hand radiographs, was significantly advanced compared to chronological age (1.2 +/- 0.1 years; p < 0.0005).

CONCLUSION

Compared to control girls, PP girls had higher leptin levels for degree of body mass index (PP girls: 9.4 +/- 0.6 ng/ml; controls: 7.8 +/- 0.6 ng/ml; p = 0.01). In PP girls, serum leptin was inversely related to birthweight (r = -0.32, p = 0.01) and positively related to free androgen index (FAI) (r = 0.71, p < 0.0005). BMD SDS was also inversely related to birthweight (r = -0.26, p < 0.05) and positively related to serum leptin (r = 0.42, p < 0.05), FAI (r = 0.45, p < 0.05) and mean serum insulin during oral glucose tolerance testing (MSI) (r = 0.59, p < 0.0005). In multiple regression, MSI was the strongest determinant of BMD SDS (beta = 0.50, p = 0.002). In conclusion, elevated BMD and serum leptin in non-obese PP girls were related to degrees of low birthweight, hyperinsulinism and hyperandrogenism. The characteristic hyperinsulinism of PP girls is proposed to be the key variable in this constellation.

Pronounced adrenarche and precocious pubarche in boys

In girls, pronounced adrenarche with precocious pubarche (PP) has been related to reduced fetal growth and to a cluster of endocrine-metabolic abnormalities. We examined whether these associations are also evident in boys with PP. The study population consisted of matched groups of boys (n = 58; age range 5-15 years) without or with a history of PP. After stratification for pubertal development, non-PP and PP boys displayed comparable results for the studied variables, including serum insulin-like growth factor I, sex hormone binding globulin, insulin-like growth factor binding proteins 1 and 3, indices of circulating glucose and insulin responsiveness to an oral glucose load, and birth weight SD score. In conclusion, the present results indicate that adrenarche-driven PP in boys is, in contrast to PP in girls, not associated with a cluster of endocrine-metabolic abnormalities and is not related to reduced fetal growth. These observations support the view that adrenarche-driven PP in boys may be regarded as a variant of normal development. Copyrightz1999S.KargerAG,Basel

Premature adrenarche--normal variant or forerunner of adult disease?

Adrenarche is the puberty of the adrenal gland. The descriptive term pubarche indicates the appearance of pubic hair, which may be accompanied by axillary hair. This process is considered premature if it occurs before age 8 yr in girls and 9 yr in boys. The chief hormonal product of adrenarche is dehydroepiandrosterone (DHEA) and its sulfated product DHEA-S. The well documented evolution of adrenarche in primates and man is incompatible with either a neutral or harmful role for DHEA and implies most likely a positive role for some aspect of young adult pubertal maturation and developmental maturation. Premature adrenarche has no adverse effects on the onset and progression of gonadarche in final height. Both extra- and intraadrenal factors regulate adrenal androgen secretion. Recent studies have shown that premature adrenarche in childhood may have consequences such as functional ovarian hyperandrogenism, polycystic ovarian syndrome, and insulin resistance in later life, sometimes already recognizable in childhood or adolescence. Premature adrenarche may thus be a forerunner of syndrome X in some children. The association of these endocrine-metabolic abnormalities with reduced fetal growth and their genetic basis remain to be elucidated.

Adrenal hyperandrogenism in adolescent girls with a history of low birthweight and precocious pubarche

OBJECTIVE

Girls with precocious pubarche (PP) are at increased risk for ovarian dysfunction, hyperinsulinism and dyslipidaemia in adolescence, in particular when PP is preceded by reduced fetal growth. However, it is not known whether PP girls still have adrenal hyperandrogenism after puberty and if so, which fraction of PP girls develops so-called functional adrenal hyperandrogenism (FAH), an entity characterized by ACTH-dependent 17-ketosteroid excess.

PATIENTS AND DESIGN

Data were longitudinally collected from 47 girls with PP: at birth (weight for gestational age), at diagnosis of PP (age 6.7+/- 1.1 years) and in adolescence (age 15.0+/-1.9 years).

MEASUREMENTS

Serum dehydroepiandrosterone sulphate (DHEAS) and androstenedione were measured at PP diagnosis, as well as the 17-hydroxyprogesterone (17-OHP) response to ACTH; postpubertal evaluation included assessment of adrenal and ovarian function, and of insulin responses to a glucose load. PP girls were considered to have FAH in adolescence if both DHEA and androstenedione responses to ACTH were excessive (> 1500 ng/dl and > 350 ng/dl, respectively).

RESULTS

At diagnosis of PP, girls had high DHEAS and androstenedione levels, as well as high 17-OHP responses to ACTH. In adolescence, PP girls had a normal BMI, presented with mild hirsutism and had high baseline and post-ACTH concentrations of most adrenal androgens, low SHBG levels and tended to have hyperinsulinemia and to present biological signs of ovarian hyperandrogenism. More than a third of the PP cohort developed FAH in adolescence. Neither baseline DHEAS, androstenedione, nor post-ACTH 17-OHP values at diagnosis of PP predicted the development of FAH in adolescence. In PP girls, only a low weight at birth was found to be significantly associated with subsequent FAH.

CONCLUSIONS

These longitudinal findings in girls with PP point to the possibility of an endocrine sequence of prenatal onset: low weight at birth, PP in childhood and adrenal hyperandrogenism in adolescence. The pathophysiological mechanisms underpinning this newly recognized sequence remain to be identified.

Sensitization to insulin in adolescent girls to normalize hirsutism, hyperandrogenism, oligomenorrhea, dyslipidemia, and hyperinsulinism after precocious pubarche

Precocious pubarche in girls is often preceded by low weight at birth and followed by hirsutism, ovarian hyperandrogenism, and oligomenorrhea in adolescence, the latter usually being accompanied by dyslipidemia and hyperinsulinism, which are, in turn, two major risk factors for cardiovascular disease in later life. We hypothesized that insulin resistance may be a key pathogenetic factor in this sequence. We tested the hypothesis by assessing the effects of an insulin-sensitizing agent, metformin, given at a daily dose of 1275 mg for 6 months to 10 nonobese adolescent girls (mean age, 16.8 yr; body mass index, 21.9 kg/m2; birth weight, 2.7 kg) with hirsutism, ovarian hyperandrogenism (diagnosis by GnRH agonist test), oligomenorrhea, dyslipidemia, and hyperinsulinemia after precocious pubarche. Before the metformin trial, longitudinal studies in these girls had shown that hyperinsulinism was present at prepubertal diagnosis of precocious pubarche, and that it increased markedly in late puberty or early postmenarche. Metformin treatment was well tolerated and was accompanied by a marked drop in hirsutism score, insulin response to oral glucose tolerance test, free androgen index, and baseline testosterone, androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate levels (all P < 0.01). During metformin treatment, the LH and 17-hydroxyprogesterone hyperresponses to GnRH agonist were attenuated (P < 0.01); serum triglyceride, total cholesterol, and low density lipoprotein cholesterol levels decreased; and high density lipoprotein cholesterol rose. All girls reported regular menses within 4 months. Withdrawal of metformin treatment was followed, within 3 months, by a consistent reversal toward pretreatment conditions. In conclusion, metformin treatment reduced hyperinsulinemia, hirsutism, and hyperandrogenism; attenuated the LH and 17-hydroxyprogesterone hyperresponses to GnRH agonist; improved the atherogenic lipid profile; and restored eumenorrhea in nonobese adolescent girls with a history of precocious pubarche. These observations corroborate the idea that insulin resistance may indeed be a prime factor underpinning the sequence from reduced fetal growth, through precocious pubarche, to adolescent endocrinopathies that are reminiscent of so-called polycystic ovary syndrome.

Treatment of hirsutism, hyperandrogenism, oligomenorrhea, dyslipidemia, and hyperinsulinism in nonobese, adolescent girls: effect of flutamide

Functional ovarian hyperandrogenism, a variant of polycystic ovary syndrome, is often associated with hyperinsulinism and dyslipidemia. The mechanisms interlinking this triad are poorly understood; both hyperandrogenism and hyperinsulinism have been proposed as factors involved in the pathogenesis of the dyslipidemia. Precocious pubarche (PP) in girls is a risk factor for subsequent anovulation, ovarian and adrenal hyperandrogenism, hyperinsulinism and dyslipidemia. Flutamide, a nonsteroidal antiandrogen, is known to be effective in reducing hirsutism in patients with ovarian hyperandrogenism. However, the effects of flutamide on the endocrine-metabolic correlates of hyperandrogenism are uncertain. We assessed the effects of low dose flutamide treatment (250 mg daily for 18 months) on hormonal and metabolic variables in 18 nonobese adolescent girls (age, 16.8 +/- 0.3 yr) with functional ovarian hyperandrogenism (diagnosis by GnRH agonist test) after PP. Flutamide treatment was accompanied by a marked decrease in the hirsutism score, free androgen index, and testosterone, androstenedione, and dehydroepiandrosterone levels and by an increase in sex hormone-binding globulin concentrations. However, there were no substantial changes in the pattern of menstrual cycles, gonadotropin, estradiol, or dehydroepiandrosterone sulfate concentrations, and there was no detectable effect on the 17-hydroxyprogesterone response to GnRH agonist. Serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol levels decreased markedly during flutamide therapy, whereas high-density lipoprotein cholesterol, fasting glycemia/insulinemia, and the insulin response to a glucose load remained unchanged. Flutamide was well tolerated. In conclusion, low dose flutamide treatment was found to be an effective and safe approach to reduce hirsutism and circulating androgen, low-density lipoprotein cholesterol, and triglyceride levels in girls with functional ovarian hyperandrogenism after PP. However, flutamide failed to increase high-density lipoprotein cholesterol levels or decrease hyperinsulinemia, i.e. to affect two major risk factors for subsequent cardiovascular disease.

Leptin values in placental cord blood of human newborns with normal intrauterine growth after 30-42 weeks of gestation

OBJECTIVE

To evaluate leptin values in placental cord blood of newborns with normal intrauterine growth after 30-42 weeks of gestation.

DESIGN

Leptin, a protein encoded by the ob gene, plays an important role in the regulation of feeding behaviour and energy balance in rodents, primates and humans. The presence of leptin in human amniotic fluid and cord blood has recently been reported in human gestations at term and the possible role of leptin in human fetal growth suggested. However, little is known of leptin synthesis during human foetal development. Thus, the aim of our work was to measure leptin (RIA, Linco Research, Inc.) in placental cord blood of human newborns at different fetal ages.

PATIENTS

One hundred and twenty-six healthy newborns with normal intrauterine growth were studied. Twenty-nine were preterm (15 males and 14 females; gestational age: 30-36 weeks) and 99 were at term (49 males and 48 females; gestational age: 37-42 weeks).

RESULTS

Leptin values increase progressively throughout gestation from 1.30 +/- 0.53 ng/ml at 30 weeks of gestation to 7.98 +/- 4.96 ng/ml (mean +/- SD) at term, and correlate positively with birth weight (r = 0.56, p < 0. 005, n = 126), length (r = 0.37, p < 0.005, n = 126), BMI (r = 0.57, p < 0.005, n = 126), head circumference (r = 0.37, p < 0.005, n = 126), gestational age (r = 0.48, p < 0.005, n = 126) and placental weight (r = 0.38, p < 0.003, n = 59). Leptin values are statistically significantly lower (p < 0.005) preterm (median: 2.05 ng/ml; range: 0.7-8.3 ng/ml) than at term (median: 7.0 ng/ml; range: 1.1-28.1 ng/ml). Leptin values are also significantly (p < 0.005) higher in females (median: 7.2 ng/ml; range: 0.9-23.6 ng/ml, n = 62) than in males (median: 4.8 ng/ml; range: 0.7-28.1 ng/ml, n = 64), although there are no differences in weight (2,864 +/- 536 g in females vs. 2,937 +/- 744 g in males). Multiple regression analysis shows weight to be a positive sex-independent predictor of serum leptin values (p < 0.0005). Sex also proves to be a predictor of leptin, independently of weight and is higher in females than in males (p < 0.003).

CONCLUSION

Leptin is present in placental human cord blood after 30-42 weeks of gestation. Newborn weight and sex are independent predictors of leptin values.

Ovarian hyporesponsiveness to follicle stimulating hormone in adolescent girls born small for gestational age

Girls with reduced prenatal growth are known to have, at birth, a small ovarian fraction of primordial follicles and, in adolescence, a uterus and ovaries of small size. We have now examined whether reduced prenatal growth is also followed by changes in the relationships among FSH, inhibin B and estradiol in adolescent girls. We studied 48 post-menarcheal girls (age 13.6 +/- 1.4 yr) who were either born with an appropriate weight for gestational age (AGA; n=33; mean weight 3.3 Kg) or born small for gestational age (SGA; n=15; mean weight 2.4 Kg). Serum FSH, inhibin B and estradiol concentrations were measured in the early follicular phase (range: day 5 +/- 3). SGA girls had, compared to AGA girls, elevated serum FSH (7.2 +/- 0.7 vs 4.5 +/- 0.3 IU/mL; p=0.0002), similar inhibin B (62.1 +/- 8.1 vs 60.7 +/- 6.5 pg/mL) and lower estradiol concentrations (12.1 +/- 1.5 vs 21.2 +/- 2.4 pg/mL; p=0.02). SGA girls thus displayed, early after menarche, a pattern that points to hyporesponsiveness of the ovarian granulosa cell fraction and that is reminiscent of reproductive aging. In conclusion, the gynecological correlates of prenatal growth restriction are herewith extended to include ovarian hyporesponsiveness to FSH in adolescence.

Reduced uterine and ovarian size in adolescent girls born small for gestational age

Reduced fetal growth is known to be associated with a reduced ovarian fraction of primordial follicles, with ovarian hyperandrogenism and anovulation in late adolescence. In this study, we examined whether adolescent girls born small for gestational age also present an abnormality in uterine or ovarian size. Standardized ultrasound measurements of the internal genitalia were performed in 36 healthy post-menarcheal girls (mean age 14 y) born with a size that was either appropriate for gestational age (AGA) or small (SGA), birth weight averaging 0.1 and -3.0 SD, respectively; clinical and endocrine characteristics were documented concomitantly. Compared with AGA girls, the SGA girls had a smaller uterus (mean difference of 20%; p < 0.006) and a reduced ovarian volume (mean difference of 38%; p < 0.0002). In conclusion, the gynecological correlates of prenatal growth restriction are herewith extended to include a reduced size of the uterus and the ovaries.

Precocious pubarche in girls and the development of androgen excess

The prevalence of ovarian hyperandrogenism, hyperinsulinism and dyslipidemia is increased among adolescent girls with a history of premature pubarche (defined as the appearance of pubic hair before the age of 8 yr). The ovarian hyperandrogenism is characterized by clinical signs of androgen excess and by an exaggerated ovarian 17-hydroxyprogesterone response to GnRH agonist stimulation. The hyperinsulinism and dyslipidemia are detectable before and during pubertal development, and are commonly accompanied by low serum levels of insulin-like growth factor binding-protein 1 (IGFBP-1) and sex hormone-binding globulin (SHBG), and by an increased prevalence of anovulation from late adolescence onwards, even in the absence of clinical signs of androgen excess. In girls, premature pubarche, hyperinsulinism, low IGFBP-1, dyslipidemia, anovulation and hyperandrogenism--and some combinations of these--have been related to reduced fetal growth, indicating that these constellations or sequences may have a prenatal origin. Together, these findings suggest that premature pubarche in girls should no longer be merely regarded as a normal variant of development, but rather as a childhood marker pointing to an increased risk for a polyendocrine-metabolic disorder of prenatal origin.

Identification of three novel mutations in the insulin receptor gene in type A insulin resistant patients

Type A insulin resistance syndrome is characterized by the association of ovarian hyperandrogenism, acanthosis nigricans, and severe insulin resistance. We have identified three novel mutant alleles of the insulin receptor gene in 3 patients with type A syndrome, a severe form of insulin resistance. Two of the patients were sisters (A1, A2), 1 of them was a compound heterozygote for a mutation at the 3'-splice acceptor site of intron 21 (AG-->AA), and a missense mutation Val140Leu in exon 2. Her sister was a simple heterozygote for the 3'-splice acceptor mutation. The third patient (A3) was heterozygous for the missense mutation Ala1028Val in exon 17, in the consensus sequence for ATP binding.

Endocrinology and metabolism after premature pubarche in girls

The prevalence of functional ovarian hyperandrogenism, hyperinsulinism and dyslipidaemia is increased in adolescent girls with a history of premature pubarche, defined as the appearance of pubic hair before the age of 8 years. The ovarian hyperandrogenism is characterized by clinical signs of androgen excess and an exaggerated ovarian 17-hydroxyprogesterone response to gonadotrophin-releasing hormone agonist stimulation. The hyperinsulinism and dyslipidaemia are detectable before and during pubertal development, and they are commonly accompanied by low serum levels of insulin-like growth factor binding protein-1 (IGFBP-1) and sex hormone binding globulin, and by an increased prevalence of anovulation from late adolescence onwards. In girls, premature pubarche, hyperinsulinism, low serum levels of IGFBP-1, dyslipidaemia, anovulation and hyperandrogenism (or various combinations of these conditions) have been related to reduced fetal growth, indicating that these constellations or sequences may have a prenatal origin. These findings suggest that premature pubarche in girls should no longer be regarded as merely a normal variant of development, but rather as a childhood marker pointing to an increased risk of a polyendocrine-metabolic disorder of prenatal origin.

Corticotropin-releasing hormone: a potent androgen secretagogue in girls with hyperandrogenism after precocious pubarche

CRH is an adrenal androgen secretagogue in men and has been proposed as a candidate regulator of adrenarche. CRH also affects androgen production by theca cells and may be involved in the pathogenesis of ovarian hyperandrogenism (OH). Precocious pubarche (PP) in girls can precede adolescent OH, a condition characterized by a high ovarian 17-hydroxyprogesterone (17-OHP) response 24 h after GnRH agonist challenge. In adolescent girls with a history of PP, we assessed the early androgen response to CRH, as well as the CRH effect on the late ovarian response to GnRH agonist. Within a randomized cross-over design, saline or CRH (human CRH 1 microg/kg x h in saline) was infused over 3-h (1100-1400 h) into 12 adolescent girls (age 17+/-2 yr; body mass index 21.4+/-0.9 Kg/m2) who had been pretreated with dexamethasone (1 mg at 0 h) and GnRH agonist (leuprolide acetate 500 microg sc at 0800 h = time 0). All adolescents had hirsutism, irregular menses, hyperandrogenemia, and hyperinsulinemia after PP. Serum LH, FSH, androstenedione, dehydroepiandrosterone (DHEA), and DHEA-sulfate (DHEAS) were measured at time 0, 3, 6, and 24 h, and ACTH and 17-OHP were measured at time 0, 6, and 24 h. ACTH concentrations at the end of saline or CRH infusions were less than 45 pg/mL; neither saline nor CRH infusions evoked early changes in 17-OHP levels. Within 3 h of CRH infusion, DHEAS increased by 46%, on average; androstenedione increased 2.5-fold and DHEA increased 5-fold duringCRH infusion (all P < 0.0001 compared with saline). There was no detectable CRH effect on the responses of LH, FSH, DHEA, DHEAS, 17-OHP, androstenedione, testosterone, and estradiol 24 h after GnRH agonist administration; five of 12 girls had elevated 17-OHP responses suggestive of OH. In conclusion, CRH was found to be a potent adrenal androgen secretagogue in adolescent girls with hyperandrogenism after PP. In this study, CRH failed to detectably affect the ovarian androgen response to gonadotropins.

Exaggerated adrenarche and hyperinsulinism in adolescent girls born small for gestational age

Serum dehydroepiandrosterone-sulfate (DHEAS) is a classic marker for adrenarche and, subsequently, for the individual hormonal milieu. We have tested the hypothesis that prenatal growth reduction is followed by exaggerated adrenarche. Serum DHEAS, androstenedione and insulin concentrations were determined together with fasting glycemia in matched populations of asymptomatic, non-obese, post-menarcheal girls (mean age 14 yr) who were born either with a strictly appropriate weight for gestational age (AGA) or small for gestational age (SGA). When compared to AGA girls, the SGA girls had identical glucose levels, higher values for insulin and androstenedione (p<0.01), and a two-fold rise of DHEAS concentrations (p<0.0001). In conclusion, girls with prenatal growth reduction were found to be prone to develop, besides hyperinsulinism, a variant of exaggerated adrenarche. It remains to be verified whether the exaggerated adrenarche in adolescence is followed by adrenal hyperandrogenism throughout adulthood and senescence.

Increased prevalence of type 2 diabetes mellitus and impaired glucose tolerance in first-degree relatives of girls with a history of precocious pubarche

OBJECTIVE

To assess whether abnormal responses to an oral glucose load, dyslipidaemia and hyperandrogenaemia, which are commonly found in girls with a history of precocious pubarche, can also be detected in first-degree relatives of these patients.

PATIENTS AND DESIGN

Sixty first-degree relatives (age, 41.4 +/- 4.4 years; BMI, 26.9 +/- 3.3 kg/m2) of girls diagnosed with precocious pubarche were studied. The prevalence of gestational diabetes mellitus and the hirsutism score were assessed in the females. The study was performed during the early follicular phase of the menstrual cycle in females and at random in males.

MEASUREMENTS

All subjects underwent a standard 75 g 2-h oral glucose tolerance test (OGTT). Serum lipids and lipoproteins were measured in baseline blood samples in all subjects, while serum testosterone, sex hormone-binding globulin (SHBG) levels and the free androgen indices were determined only in females. Impaired glucose tolerance (IGT) and type 2 diabetes mellitus were diagnosed according to the criteria of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus.

RESULTS

Seven subjects (11.6%) had type 2 diabetes while a further 14 (23.3%) had IGT; prevalences significantly higher than those reported for the present population of the same age (type 2 diabetes, 2.5% and IGT, 7. 5%; P < 0.001 and P < 0.001, respectively). BMIs were similar in patients with either normal or abnormal glucose tolerance. Abnormal levels of at least two lipid parameters were found in 40% of subjects. Four out of 10 hirsute women and six non-hirsute women reported gestational diabetes. Mean serum SHBG levels were lower in female relatives compared with population controls (P < 0.0005).

CONCLUSIONS

First-degree relatives of girls with precocious pubarche are at a higher risk of impaired glucose tolerance and type 2 diabetes which, in most cases, is accompanied by an unfavourable lipid profile. Hyperandrogenism and an increased prevalence of gestational diabetes mellitus are frequent among females. These data may prove useful in identifying a specific subset of the population at increased risk of developing metabolic disturbances known to predispose to cardiovascular disease.

Corticotropin-releasing hormone as adrenal androgen secretagogue

The regulation of adrenarche is one of the enigmas of pediatric endocrinology. Adrenarche is thought to be governed by a dual control mechanism in which an adrenal androgen secretagogue acts upon a zona reticularis primed by ACTH. We hypothesized that corticotropin-releasing hormone (CRH) may serve as adrenal androgen secretagogue. We tested the concept by infusing either saline or human (h) CRH (1 microg/kg/h in saline) over 3 h, after overnight dexamethasone pretreatment, into eight young men within a randomized, cross-over study design. Serum ACTH and dehydroepiandrosterone-sulfate were measured once hourly; DHEA, androstenedione and 17-hydroxy-progesterone were determined at baseline and after 3 h of saline/hCRH infusion. ACTH levels remained unaltered during saline infusion and average ACTH responses amounted to 13 pg/mL (3.3 pmol/L) during hCRH infusion. Neither saline nor hCRH infusion altered 17-hydroxy-progesterone levels. Serum dehydroepiandrosterone-sulfate rose swiftly within 3 h of hCRH infusion and remained unchanged after saline (mean increase 37 versus 1%; p < 0.01). On average, serum DHEA doubled and androstenedione tripled during hCRH infusion, although no changes were observed during saline infusion (p < 0.01). In conclusion, CRH appears to have the capacity to act as adrenal androgen secretagogue. We suggest that the enigma of adrenarche may have an elegant solution, with CRH and ACTH coupled in sequence at the hypothalamic-pituitary level, and in parallel within the zona reticularis, just as they presumably are within the fetal adrenal, which is exposed to CRH of placental origin.

Precocious pubarche, dyslipidemia, and low IGF binding protein-1 in girls: relation to reduced prenatal growth

An increasing series of pediatric endocrinopathies and metabolic anomalies has been recognized as related to reduced prenatal growth. We have tested whether the association of precocious pubarche (PP), dyslipidemia, and low serum IGF binding protein-1 in girls is also related to reduced prenatal growth. Fasting serum lipids, lipoproteins, and IGFBP-1 concentrations were measured in 187 girls (83 without PP and 104 with PP; mean age, 11.8 y; range, 5-18 y) with known birthweight and gestational age, the latter being transformed into birthweight SD scores. Birthweight SD scores of girls with PP were lower than those of girls without PP. Within the group of PP girls, those with dyslipidemia and low IGFBP-1 had lower (p < 0.0001) birth-weight SD scores (-2.02+/-0.23; mean +/- SEM) than those with normal lipids, lipoproteins, and IGFBP-1 (-0.37+/-0.15), whereas girls with an intermediate number of abnormalities had intermediate birthweight SD scores (-0.80+/-0.18). In conclusion, dyslipidemia and low serum IGFBP-1 in girls with PP were found to be related to reduced prenatal growth, an observation pointing to the prenatal origin of these metabolic abnormalities.

Anovulation after precocious pubarche: early markers and time course in adolescence

Adolescent girls with a history of precocious pubarche (PP) are known to be at increased risk for ovarian hyperandrogenism, an endocrinopathy related to reduced fetal growth, but the characteristics of their ovulatory function have not been fully documented. We assessed ovulatory function by weekly urinary LH and salivary progesterone measurements over 3 consecutive months in 85 adolescent girls with known weight and gestational age at birth: 49 girls had no history of PP (age, 14.7+/-1.7 yr), and 36 had a history of PP (age, 14.4+/-2.0 yr); 55 girls were in the early postmenarcheal phase (0-3 yr after menarche), and 30 were in the late postmenarcheal phase (> 3 yr after menarche). In girls with PP, the 17-hydroxyprogesterone (17-OHP) response to ACTH was determined at prepubertal diagnosis of PP, and serum androgen and gonadotropin concentrations were measured in adolescence together with insulin responses to an oral glucose load. Early postmenarche, the fraction of girls with ovulations was similar in the non-PP and PP subgroups (61% vs. 62%), as was the fraction of ovulatory cycles (25% vs. 22%). Late postmenarche, however, the fractions of ovulating girls and ovulatory cycles were strikingly higher (P < or = 0.001) in the non-PP than in the PP subgroup (91% vs. 20% and 47% vs. 12%). Within the PP subgroup, anovulatory girls were found to have a lower weight SD score at birth (mean+/-SEM) than ovulatory girls (-1.22+/-0.3 vs. -0.36+/-0.3; P = 0.03), a higher 17-OHP response to ACTH before puberty (333.1+/-31 vs. 203.8+/-26 ng/dL; P < 0.002), and, in adolescence, lower serum sex hormone-binding globulin levels and higher circulating LH, free androgen indexes, and insulin responses. In conclusion, these findings indicate that girls with PP are at increased risk for anovulation from late (not early) adolescence onward, particularly those girls with a low weight at birth and/or a high 17-OHP response to ACTH at prepubertal diagnosis of PP.

Sexual dimorphism in the maturation of the pituitary-gonadal axis, assessed by GnRH agonist challenge

OBJECTIVE

To assess whether the maturational changes of the pituitary--gonadal axis in a healthy population show gender-specific changes and to establish normative data for the different Tanner stages.

DESIGN

Prospective, cross-sectional study.

METHODS

The GnRH agonist leuprolide acetate (500 microgram) was administered s.c. to 60 boys and 81 girls (age range, 5--17 years). Serum steroids and gonadotropins were determined at 0 and 24 h and at 0, 3 and 24 h after GnRH agonist challenge respectively, whereas IGF-I, IGF-binding protein-1 (IGFBP-1), IGFBP-3 and sex hormone-binding globulin were measured at baseline.

RESULTS

Baseline and peak LH responses to the agonist in late puberty, and basal and peak FSH levels at all Tanner stages, were higher in girls than in boys. Girls showed higher IGF-I levels than boys throughout puberty, sharper decreases in IGFBP-1 and earlier and greater increases in 17-hydroxypregnenolone, dehydroepiandrosterone (DHEA) and DHEA-sulfate. Testosterone responses to the agonist increased during puberty in males, and showed no changes in females. Conversely, estradiol responses rose throughout puberty in females and remained unchanged until late puberty in males.

CONCLUSION

Leuprolide acetate stimulates gonadotropin and gonadal steroid secretion during puberty in both sexes and increases FSH levels in prepubertal girls. Pubertal maturation of gonadotrope function is gender specific, as it appears to involve increases in both the releasable and reserve pools of LH in males, and of LH and FSH in females. The earlier increase in Delta(5)-steroids in girls may suggest a sharper rise in ovarian cytochrome P450c17 activity along the Delta(5)-steroid pathway, while the failure of estradiol to increase in response to leuprolide acetate in early pubertal males suggests a late maturation of aromatase activity.

[The effectiveness of recombinant growth hormone in height deficiency due to intrauterine growth retardation]

BACKGROUND

Intrauterine growth retardation (IUGR) is considered to be responsible for approximately 20% of short stature in adulthood. Although GH secretion is normal in the majority of cases, excellent results have been published by some authors using GH to treat children with height deficiency due to IUGR.

PATIENTS AND METHODS

Thirty children with a history of IUGR with chronological ages between 2 and 7 years and height less than 2 SD were randomized in two groups for one year: a) control group, no treatment, 14 cases, and b) treatment group, 1 U/kg/week of recombinant GH, 16 cases. Growth and maturation were analysed periodically in both groups. In addition, serum levels of GH, IGF-I, IGFBP3 and GHBP were measured before and under treatment and adverse events were assessed in treatment group.

RESULTS

In the treated group significant increments in growth rate, cm/year (median = 6.91 vs 9.94), improvement in height SDS (median = -2.19 vs -1.63) and positivation of growth rate (median = -0.13 vs 3.17) were observed compared with the control group. Bone age evolved parallelly to chronological age and the height age/bone age ratio increased throughout the study under GH therapy. Hormonal findings in the treated group showed a significant increase in IGF-I and IGFBP3 values. Glycaemia levels increased without exceeding upper normal levels in the treated group.

CONCLUSION

GH was effective in promoting growth in this short-term study in children with height deficiency due to IUGR. Close follow-up is required to detect any adverse event, particularly those related to carbohydrate metabolism.

A limited repertoire of mutations of the luteinizing hormone (LH) receptor gene in familial and sporadic patients with male LH-independent precocious puberty

Herein, we report mutation analysis of the LH receptor gene in 17 males with LH-independent precocious puberty, of which 8 were familial and 9 had a negative family history. A total of 7 different mutations (all previously reported) were detected in 12 patients. Among 10 European familial male-limited precocious puberty (FMPP) patients who had a LH receptor gene mutation, none had the Asp578Gly mutation, which is responsible for the vast majority of cases in the U.S. The restricted number of activating mutations of the LH receptor observed in this and other studies of FMPP strongly suggests that an activating phenotype is associated with very specific sites in the receptor protein. Clinical follow-up of the 5 patients who did not have LH receptor mutations shows that such cases most likely do not have true FMPP. LH receptor mutation analysis provides a sensitive tool for distinguishing true FMPP from other causes of early-onset LH-independent puberty in males.

Protein in infant formulas. Future aspects of development

Cow's milk protein intolerant infants (CMPI), shifted to a cow's milk protein hydrolysate based formula, often experience an improvement in signs of malabsorption; on the other hand, they also present a pattern of watery stools. In an attempt to find high levels of some gastrointestinal hormones that might induce hypermotility, motilin and neurotensin levels were studied in infants on starting formula and in cow's milk protein intolerant infants, on a cow's milk protein hydrolysate based formula. In 12 infants on unmodified cow's milk based formula (starting formula), motilin levels were: mean 71.66 pmol/L (s: 17); neurotensin 26.53 (s: 10.9). In 19 cow's milk protein intolerant infants on a cow's milk protein hydrolysate based formula, motilin levels were: mean 163.65 pmol/L (s: 70.06) (p<0.05); neurotensin: 31.76 pmol/L (s: 15.03) (p>0.05). Motilin (but not neurotensin) is higher in cow's milk protein intolerant infants on a cow's milk protein hydrolysate based formula. We conclude that high motilin levels can induce a different pattern of motility, and can be a pathogenetic factor in the persistence of loose and watery stools in infants with CMPI on a protein hydrolysate based formula.

Premature pubarche, ovarian hyperandrogenism, hyperinsulinism and the polycystic ovary syndrome: from a complex constellation to a simple sequence of prenatal onset

Adolescent girls with a history of premature pubarche have an increased incidence of functional ovarian hyperandrogenism [a form of polycystic ovary syndrome (PCOS)] at adolescence, which is usually associated with hyperinsulinemia and dyslipemia. The hyperinsulinemia and lipid disturbances can often be detected in the prepubertal period and throughout puberty, and are associated with an exaggerated ovarian androgen synthesis. Birthweight SD scores are lower in premature pubarche girls than in control girls, and particularly so in those girls who show hyperinsulinemia and subsequently develop ovarian hyperandrogenism. Therefore, although the mechanisms interlinking the triad of premature pubarche, hyperinsulinism and ovarian hyperandrogenism remain enigmatic, these data indicate that the triad may result, at least in part, from a common early origin, rather than from a direct interrelationship later in life.

Precocious pubarche, hyperinsulinism, and ovarian hyperandrogenism in girls: relation to reduced fetal growth

Pronounced adrenarche with precocious pubarche (PP) in girls has been associated with hyperinsulinism and subsequent functional ovarian hyperandrogenism (FOH). Recently, pronounced adrenarche and insulin resistance have each been related to low birth weight. We have now tested the hypothesis that the frequent concurrence of PP with pronounced adrenarche, FOH, and hyperinsulinemia in girls may be secondary to separate relationships between these conditions and low birth weight. A total of 185 girls (aged 5-18 yr) without endocrinopathy or with PP and pronounced adrenarche with or without FOH were studied; mean serum insulin (MSI) concentrations were determined after a standardized oral glucose tolerance test. Birth weight SD scores [mean (SEM)] of control girls (0.38+/-0.08; n = 83) were higher (P < 0.0001) than those of PP girls (-0.81+/-0.13; n = 102). Among postmenarcheal PP girls, birth weight SD scores of girls without FOH (-0.25+/-0.19; n = 25) were higher (P < 0.0001) than those in girls with FOH (-1.51+/-0.28; n = 23). In pubertal girls (n = 145), MSI levels correlated negatively with birth weight SD scores (r = -0.48; P < 0.05), independently of PP. MSI levels in girls with birth weight below 1 SD (93+/-9 mU/L; n = 33) were higher (P < 0.0001) than those in girls with birth weight between -1 and +1 SD (52+/-2 mU/L; n = 94), whereas glycemia profiles were comparable. Integration of the aforementioned data suggests that there may be a sequence in the associations between reduced fetal growth and components of the postnatal endocrine system; minor fetal growth reduction appears to be associated with amplified adrenarche, whereas more pronounced prenatal growth restriction seem to precede FOH and hyperinsulinemia during adolescence. In conclusion, these findings corroborate the hypothesis that the frequent concurrence of PP (with pronounced adrenarche), FOH, and hyperinsulinemia in girls may result from a common early origin (low birth weight serving as a marker), rather than from a direct interrelationship later in life.

Hyperinsulinaemia, dyslipaemia and cardiovascular risk in girls with a history of premature pubarche

Girls with a history of premature pubarche, i.e. appearance of pubic hair before 8 years of age, show hyperinsulinism in response to an oral glucose tolerance test. As hyperinsulinaemia has a major role in dyslipaemia, and is considered an independent risk factor for cardiovascular disease, we assessed the patterns of plasma insulin concentration after a standard oral glucose tolerance test as well as fasting serum lipid, lipoprotein, and sex hormone-binding globulin concentrations in girls (n = 81) with premature pubarche compared with girls (n = 55) matched with them for stage and bone age to ascertain their metabolic states to identify those potentially at risk for the development of premature cardiovascular disease. Mean serum insulin concentrations were higher in patients at all pubertal stages, and associated with elevated serum triglyceride, very low density cholesterol and very low density triglyceride concentrations (p value range 0.04 to < 0.0001) but reduced sex hormone-binding globulin. Premature pubarche patients also displayed higher low density to high density lipoprotein cholesterol ratios compared with control subjects (p = 0.004 to 0.008). In conclusion, hyperinsulinaemia, decreased sex hormone-binding globulin concentrations and an unfavourable lipid pattern are common features in premature pubarche girls supporting the contention that atherogenic abnormalities composing the metabolic syndrome could start in childhood. To determine the clinical sequelae of such clustering of metabolic deviations, girls who were identified need to be followed up for the potential development of premature cardiovascular disease.

Changes in growth, growth hormone, and insulin-like growth factor-I (IGF-I) after orthotopic liver transplantation

Growth failure is an important consequence of chronic liver disease in childhood. Insulin-like growth factor-I (IGF-I), which is synthesized and released by the liver, plays an important role as a growth regulator in humans. We examined the growth hormone (GH)/IGF-I axis before and after orthotopic liver transplantation (LT) in 14 children aged between 2 and 11 years (mean 5.6 +/- 1.1 years). Pre-transplantation serum GH levels (7.5 +/- 1.2 ng/ml) were significantly higher (P < 0.001) compared with controls (5 +/- 0.5 ng/ml). However, post-transplantation levels (1.8 +/- 0.8 ng/ml) did not differ from those in the control group. Serum IGF-I levels showed a statistically significant increase after LT (20.1 +/- 9.4 vs 190 +/- 66.2 ng/ml; P < 0.001) and became indistinguishable from the levels in the control group (180 +/- 96 ng/ml). In comparison with pre-transplantation data (z - 2.70), there was an increase in height 4 years postoperatively (z - 1.68). Catch-up growth was highly significant, in particular during the 1st year after LT (z -1. 58 +/- 1.63 vs 2.59 +/- 5.29; P < 0.01). We conclude that a GH resistance state found in patients with severe chronic liver disease reverted following LT. Given that IGF-1 depends upon liver function, this could be one of the main factors in the significant catch-up growth in pediatric LT recipients.

Diagnosis and treatment in utero of goiter with hypothyroidism caused by iodide overload

A fetal goiter was detected by ultrasonography in a woman receiving potassium iodide. After this medication was discontinued at 29 weeks, a fetal hypothyroidism was confirmed by cordocentesis, and two doses of levothyroxine were administered by amniocentesis. At 34 weeks repeated cordocentesis showed fetal euthyroidism and ultrasonography shrinkage of the goiter. Growth and development normal at 1 year.

Insulin resistance, premature adrenarche, and a risk of the Polycystic Ovary Syndrome (PCOS)

Timing of puberty and final height are usually normal in girls with a history of premature adrenarche. However, these patients show an increased frequency of ovarian hyperandrogenism, hyperinsulinism and dyslipemia at adolescence. The hyperinsulinemia and lipid disturbances can often be detected in the prepubertal period, recommending long-term follow-up of these patients into adulthood.