Evaluación del desempeño cognitivo en escolares y adolescentes con diabetes mellitus tipo 1

The study aimedto evaluate the cognitive functioning of children and adolescents with type 1 diabetes mellitus (T1DM) recruited from the IAHULA Endocrinology Outpatient Unit and to compare it to that of non-diabetics as to investigate the influence on cognition of factors re-lated to the disease. An analytical, cross-sectional observational study was carried out on a group of 30 patients with T1DM between 8 and 16 years of age and on a control group of 30 individuals matched by age, gender, education, and socioeconomic status. Interrogation and review of medi-cal records to obtain data on the clinical characteristics and treatment of T1DM were conducted. The WISC IV test was then applied to evaluate cognition and intellectual coefficient (IQ). The average age of the diabetic patients was 13.27±2.31 years, and half of them were male. Lower scores were found in the different domains of the WISC IV in the group with T1DM (p<0.01). The IQ was found to be lower in children with T1DM than in con-trols (75.47±13.87 vs. 88.57±11.06; p=0.0001). Likewise, a higher fre-quency of IQ scores below the 10th percentile was observed in the diabetic children (63.3% vs. 33.3%; p=0.02; Odds ratio: 3.45; 95%CI: 1.19-9.99). It was concluded that T1DM negatively impacts the cognitive performance of children and adolescents. Cognitive evaluation of these patients is recom-mended, as it could affect their daily life.

Metabolic Syndrome as a Risk Factor for Sensorineural Hearing Loss in Adult Patients with Turner Syndrome

Background and purpose

Metabolic syndrome (MetS) is a disorder associated with an increased risk of cardiovascular disease. The frequency of each component of MetS in Turner syndrome (TS) subjects is high. An elevated incidence of hearing loss has also been reported in TS. Sensorineural hearing loss (SNHL) affects at least half of young women with TS. The association between MetS and SNHL has not been previously considered in TS. The aim of this study is to evaluate the association between these two conditions.

Patients and Methods

Cross-sectional anthropometric, cardio-metabolic and audiological data were obtained from a cohort consisting of unrelated TS subjects (>20 years of age; n = 93). Metabolic syndrome was defined according to the International Diabetes Federation criteria. Types and severity of hearing loss were based on the American Speech Hearing Association guidelines.

Results

Hearing loss was detected in 74% of ears from adult TS subjects and SNHL was observed in half of our TS subjects. The prevalence of MetS in TS subjects with or without SNHL was 64% and 11%, respectively (P < 0.05). After adjusting for age, MetS was related to a ninefold increase in the odds of SNHL. This odds increased in a stepwise manner as the number of MetS components increased.

Conclusion

MetS and its individual components were associated factors for SNHL in TS subjects. A reduction in the number and severity of the components of MetS might potentially contribute to decreasing the progression of SNHL at younger ages, but further studies will be needed to explain the underlying pathological mechanism connecting MetS and SNHL.

Near Adult Height in Girls with Turner Syndrome Treated with Growth Hormone Following Either Induced or Spontaneous Puberty

OBJECTIVE

To understand whether spontaneous vs induced puberty and the type and route of estrogen influence the height of girls with Turner syndrome on growth hormone (GH).

STUDY DESIGN

Search of an international database of children treated with GH revealed 772 girls with Turner syndrome followed from GH initiation to near adult height. Data from girls with sustained spontaneous puberty (n = 145) were compared with those requiring estrogens for induction or maintenance of puberty (n = 627).

RESULTS

At GH start, mean age (7.5 vs 7.9 years), weight (-1.7 vs -1.7 SDS), and body mass index (0.2 SDS vs 0.1 SDS) were similar for girls with spontaneous puberty and with induced puberty. Although those girls with spontaneous puberty were shorter than those with induced puberty, when midparental height was taken into consideration, starting heights in both groups averaged -2.8 SDS. Both groups received approximately 0.3 mg/kg/week of GH. Girls with spontaneous puberty initiated puberty and reached near adult height earlier than girls with induced puberty (12.6 ± 1.8 years vs 13.4 ± 1.4 years and 16.0 ± 1.3 years vs 16.9 ± 1.4 years, respectively). Although girls with spontaneous puberty grew more in the first year of GH therapy and between the onset of puberty and near adult height (11.0 cm vs 9.3 cm), height SDS at near adult height and the length of time in puberty before reaching near adult height were comparable. A 45,X karyotype was detected in 22.1% of girls with spontaneous puberty and in 58.4% of girls with induced puberty. Patients receiving transdermal estrogens did not grow better than those on oral estrogens. Adverse event reporting was comparable between groups.

CONCLUSIONS

Girls with Turner syndrome with spontaneous puberty tended to grow better in response to GH than girls with induced puberty, but not enough to produce a difference in height SDS at near adult height.

Anthropometric variables as cardiovascular risk predictors in a cohort of adult subjects with Turner syndrome

BACKGROUND AND PURPOSE

Excessive adiposity is associated with cardiometabolic complications in Turner syndrome (TS) subjects. Reference data for predictive anthropometric indices of overweight/obesity and metabolic syndrome (MetS) are lacking for subjects with TS. The purpose of this study was to identify the best anthropometric predictor of cardiometabolic risk in a Latin-American cohort of TS subjects.

PATIENTS AND METHODS

This was a cross-sectional correlational study conducted in adult TS subjects (n=88) over the past seven years. Anthropometric parameters, body composition and biochemical variables were evaluated in a study and in a reference (n=57) group. Overweight/obesity and MetS were diagnosed using international consensus. The area under the ROC curve (AUC-ROC) was then used to determine the value of each anthropometric variable in predicting MetS or overweight/obesity.

RESULTS

The prevalence of MetS and overweight/obesity in TS subjects was 40% and 48%, respectively. All anthropometric and cardiometabolic variables were significantly increased in TS subjects when compared to the reference group, except for body mass index (BMI) and HDL-c. To detect MetS and overweight/obesity, waist to height ratio (WHtR) was found to have a higher correlation with cardiometabolic variables (TC, LDL-c, HDL-c levels and the LDL-c/HDL-c ratio), and to have a higher AUC-ROC and odds ratio than BMI, waist circumference (WC) and the waist to hip ratio (WHR).

CONCLUSION

The prevalence of MetS and overweight/obesity is elevated in TS subjects. WHtR was the most useful variable in predicting the presence of MetS and overweight and obesity in this TS cohort. A combination of WHtR with BMI or with WC could have the best clinical utility in identifying adult TS subjects with overweight/obesity and MetS, respectively.

Epigenetics in Turner syndrome

Background

Monosomy of the X chromosome is the most frequent genetic abnormality in human as it is present in approximately 2% of all conceptions, although 99% of these embryos are spontaneously miscarried. In postnatal life, clinical features of Turner syndrome may include typical dysmorphic stigmata, short stature, sexual infantilism, and renal, cardiac, skeletal, endocrine and metabolic abnormalities.

Main text

Turner syndrome is due to a partial or total loss of the second sexual chromosome, resulting in the development of highly variable clinical features. This phenotype may not merely be due to genomic imbalance from deleted genes but may also result from additive influences on associated genes within a given gene network, with an altered regulation of gene expression triggered by the absence of the second sex chromosome. Current studies in human and mouse models have demonstrated that this chromosomal abnormality leads to epigenetic changes, including differential DNA methylation in specific groups of downstream target genes in pathways associated with several clinical and metabolic features, mostly on autosomal chromosomes. In this article, we begin exploring the potential involvement of both genetic and epigenetic factors in the origin of X chromosome monosomy. We review the dispute between the meiotic and post-zygotic origins of 45,X monosomy, by mainly analyzing the findings from several studies that compare gene expression of the 45,X monosomy to their euploid and/or 47,XXX trisomic cell counterparts on peripheral blood mononuclear cells, amniotic fluid, human fibroblast cells, and induced pluripotent human cell lines. From these studies, a profile of epigenetic changes seems to emerge in response to chromosomal imbalance. An interesting finding of all these studies is that methylation-based and expression-based pathway analyses are complementary, rather than overlapping, and are correlated with the clinical picture displayed by TS subjects.

Conclusions

The clarification of these possible causal pathways may have future implications in increasing the life expectancy of these patients and may provide informative targets for early pharmaceutical intervention.

Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy

Growth hormone deficiency (GHD) in adulthood is associated with an increased risk of developing adverse cardiovascular events and with reduced life expectancy. Cardiovascular and metabolic abnormalities have so far been evaluated only in a small number of children with GHD and adolescents. In this article we review these abnormalities and their underlying mechanisms and discuss the beneficial effect of growth hormone treatment in subjects with GHD.

Elevated second-trimester maternal serum β-human chorionic gonadotropin and amniotic fluid alpha-fetoprotein as indicators of adverse obstetric outcomes in fetal Turner syndrome

AIM

The objective of this study was to determine the ability of biochemical analytes to identify adverse outcomes in pregnancies with Turner syndrome.

METHODS

Maternal serum and amniotic fluid (AF) marker concentrations were measured in 73 singleton pregnancies with Turner syndrome (10-22 weeks of gestation). Fetal Turner syndrome was definitively established by cytogenetic analysis. Two subgroups, fetuses with hydrops fetalis versus fetuses with cystic hygroma, were compared. Receiver operating characteristic curves and relative risk were established for a cut-off multiples of the median ≥3.5 for β-subunit of human chorionic gonadotropin (hCG) or AF alpha-fetoprotein (AFP).

RESULTS

Forty-nine (67%) of 73 pregnant women had an abnormal maternal serum. While levels of pregnancy-associated plasma protein-A and free β-subunit (fβ)-hCG were not different to those of the control group, AFP, unconjugated estriol and β-hCG concentrations were significantly different in the study group (P < 0.05), when compared to those of unaffected pregnancies. Levels of β-hCG in pregnancies with hydrops fetalis were significantly higher than in those with cystic hygroma (P <0.0001), as were AF-AFP concentrations (P <0.0015). In addition, abnormalities in both maternal serum β-hCG and AF-AFP predicted fetal death. The relative risk of adverse obstetric outcome was 10.667 (P = 0.0004; 95% confidence interval [CI]: 1.554-73.203) for β-hCG and 2.19 (P = 0.0256; 95% CI: 1.001 to 4.779), for AF-AFP.

CONCLUSION

Maternal serum β-hCG and AF-AFP levels may preferentially identify those Turner syndrome pregnancies with the highest risk of fetal death.

Higher prevalence of obesity and overweight without an adverse metabolic profile in girls with central precocious puberty compared to girls with early puberty, regardless of GnRH analogue treatment

OBJECTIVES

1. To determine BMI, obesity/overweight rates, glucose and lipids at baseline, during GnRHa treatment and shortly after therapy discontinuation in female children with CPP and EP. 2. To compare this response to that seen in a similar group of untreated patients.

METHODS

A retrospective analysis of 71 children with either CPP (n = 37) or EP (n = 34) was undertaken. Forty three were treated with a GnRHa for at least 2 years, while 28 were followed without treatment.

RESULTS

At the time of diagnosis, a higher BMI (z-score of 1.1 ± 0.8 vs. 0.6 ± 0.7, p = 0.004) and a higher prevalence of obesity/overweight (72.9 vs. 35.3%, p = 0.001) was observed in subjects with CPP when compared to those with EP. Children with EP had higher fasting glucose and total cholesterol than those with CPP. BMI z-score, obesity/overweight rates, fasting glucose and lipids did not change significantly in girls with CPP or EP during 3 yrs of follow up, regardless of treatment. Weight z-scores were higher at 3 years in treated than in untreated girls with CPP (p = 0.02), while it was higher in untreated than in GnRHa-treated patients with EP at baseline, 1, 2 and 3 years (p = 0.007, p = 0.002, p = 0.02 and p = 0.04, respectively) and remained so shortly after stopping therapy (p = 0.03).

CONCLUSIONS

There is a high prevalence of obesity/overweight in girls with CPP and EP at diagnosis. However, this risk is greater in CPP than in EP girls. BMI, Obesity/overweight rates, fasting glucose and lipids remained stable in CPP and EP girls regardless of therapy. Weight z-scores were found to be higher in treated CPP girls and in untreated girls with EP.

Effect of the parental origin of the X-chromosome on the clinical features, associated complications, the two-year-response to growth hormone (rhGH) and the biochemical profile in patients with turner syndrome

Background

It is possible that genes on the X chromosome are expressed differently depending of its parental origin. The objective of this study was to determine the influence of the parental origin of the X-chromosome on phenotypic variability, response to rhGH and on the biochemical profile of TS patients.

Methods

This was a cross-sectional multicenter correlational study carried out over three years in six Latin-American university hospitals. Unrelated 45,X TS patients (n =  93; 18.3 ± 8.5 years )) were evaluated. A subgroup (n =  34) of the patients were prospectively treated with rhGH over two years. DNA profiles of patients and their mothers were compared to determine the parental origin of the retained X-chromosome through 10 polymorphic X-chromosome-STRs. The association with clinical features, biochemical profiles and anthropometric data at the beginning and after two years of rhGH treatment was determined.

Results

Seventy two percent of patients retained the maternal X chromosome (Xm). A trend towards significance between maternal height and patients final height (p ≤ 0.07) in 45,Xm subjects was observed. There was no correlation between paternal height and patient height. No differences were detected between both groups in regard to dysmorphic features, classical malformations or increase in the height-SDS after rhGH. There were higher levels of triglycerides, total and LDL cholesterol in patients >20 years who retained the Xm.

Conclusions

The parental origin of the retained X chromosome may influence lipid metabolism in TS patients, but its effect on growth seems to be minimal. No parental-origin-effect on the phenotypic features, associated anomalies and on the growth response to rhGH was found in 45,X TS individuals.

Is the growth outcome of children with idiopathic short stature and isolated growth hormone deficiency following treatment with growth hormone and a luteinizing hormone-releasing hormone agonist superior to that obtained by GH alone?

AIM

The aim of this study was to evaluate the effect of combined therapy with growth hormone (GH) and luteinizing hormone-releasing hormone agonist (LHRHa) on the near-final height (NFH) of children with idiopathic short stature (ISS) and growth hormone deficiency (GHD) in early puberty.

METHODS

A retrospective analysis of 20 patients with ISS and 9 patients with GHD treated with combined therapy was undertaken. Twelve children with ISS and ten with GHD, treated with GH alone, served as controls. Patients were matched at baseline for chronological age, bone age, height standard deviation score (SDS), and pubertal development.

RESULTS

Patients with ISS or GHD treated with combined therapy improved both their predicted adult height (PAH) at 2 years of therapy (ISS, p < 0.001; GHD, p = 0.03) and their NFH (ISS, p < 0.05; GHD, p = 0.05). Treatment with combined therapy did not generate additional benefits on the PAH after 2 years of therapy (ISS children, an increase of 7.9 +/- 4.9 cm with combined therapy vs. 7.3 +/- 6.0 cm with GH; GHD children, an increase of 6.8 +/- 7.8 cm with combined therapy vs. 5 +/- 5.9 cm with GH). The total height gain SDS was higher in patients treated with GH alone compared with those with combined therapy, but the difference was not significant (ISS children, a gain of 2.4 SDS with GH vs. 0.8 SDS with combined therapy; GHD children, a gain of 1.8 SDS with GH vs. 0.6 SDS with combined therapy).

CONCLUSIONS

Although 2 years of combined treatment with GH and LHRHa improved the PAH and the NFH of ISS and GHD patients in early puberty, this improvement was not significant compared with that observed in similar subjects treated with GH alone.

Latin American consensus: children born small for gestational age

BACKGROUND

Children born small for gestational age (SGA) experience higher rates of morbidity and mortality than those born appropriate for gestational age. In Latin America, identification and optimal management of children born SGA is a critical issue. Leading experts in pediatric endocrinology throughout Latin America established working groups in order to discuss key challenges regarding the evaluation and management of children born SGA and ultimately develop a consensus statement.

DISCUSSION

SGA is defined as a birth weight and/or birth length greater than 2 standard deviations (SD) below the population reference mean for gestational age. SGA refers to body size and implies length-weight reference data in a geographical population whose ethnicity is known and specific to this group. Ideally, each country/region within Latin America should establish its own standards and make relevant updates. SGA children should be evaluated with standardized measures by trained personnel every 3 months during year 1 and every 6 months during year 2. Those without catch-up growth within the first 6 months of life need further evaluation, as do children whose weight is ≤ -2 SD at age 2 years. Growth hormone treatment can begin in SGA children > 2 years with short stature (< -2.0 SD) and a growth velocity < 25th percentile for their age, and should continue until final height (a growth velocity below 2 cm/year or a bone age of > 14 years for girls and > 16 years for boys) is reached. Blood glucose, thyroid function, HbA1c, and insulin-like growth factor-1 (IGF-1) should be monitored once a year. Monitoring insulin changes from baseline and surrogates of insulin sensitivity is essential. Reduced fetal growth followed by excessive postnatal catch-up in height, and particularly in weight, should be closely monitored. In both sexes, gonadal function should be monitored especially during puberty.

SUMMARY

Children born SGA should be carefully followed by a multidisciplinary group that includes perinatologists, pediatricians, nutritionists, and pediatric endocrinologists since 10% to 15% will continue to have weight and height deficiency through development and may benefit from growth hormone treatment. Standards/guidelines should be developed on a country/region basis throughout Latin America.

GHR and VDR genes do not contribute to the growth hormone (GH) response in GH deficient and Turner syndrome patients

We have prospectively assessed the influence of GHR and VDR gene polymorphisms on the response to rhGH therapy in Venezuelan children with growth hormone deficiency (GHD, n=28) and Turner syndrome (TS, n=25). Clinical data during rhGH treatment were compared in GH and TS patients with different genotypes. PCR amplifications were performed to obtain the genotype frequencies of the polymorphisms. Clinical data at the start of treatment and rhGH doses were indistinguishable among patients with GHD or TS with different GHR or VDR genotypes. After the first two years of rhGH treatment, clinical data in both GHD and TS patients were not different according GHR or VDR genotypes. In addition, there was no significant difference among the subjects when both these genotypes were combined. Gene polymorphisms in low penetrance genes do not contribute to the rhGH therapy response in patients with GHD and TS.

The triglyceride/HDL-cholesterol ratio as a marker of cardiovascular risk in obese children; association with traditional and emergent risk factors

OBJECTIVES

To determine the presence of traditional and emergent cardiovascular risk factors and to evaluate the triglyceride/high-density lipoprotein cholesterol (Tg/HDL-C) ratio as a marker for cardiovascular disease and metabolic syndrome (MS) in obese children.

MATERIAL AND METHODS

Sixty-seven prepubertal children of both sexes, between the ages of 6 and 12 yr, 20 normal-weight children, 18 overweight, and 29 obese subjects, were studied. Anthropometric measures, blood pressure, body mass index (BMI), and fat mass (FM), were measured. Plasma glucose, serum insulin, lipid profile, C-reactive protein (CRP), and leptin concentrations were quantified. Glucose and insulin concentrations 2 h post-glucose load were determined. The Tg/HDL-C ratio, homeostasis model assessment index (HOMA), and quantitative insulin sensitivity check index (QUICKI) were calculated.

RESULTS

Systolic, diastolic, and mean blood pressures (MBP), low-density lipoprotein cholesterol (LDL-C), Tg/HDL-C, total cholesterol/HDL-C, LDL-C/HDL-C ratios, basal and 2 h postload insulin, CRP, and leptin were significantly higher and the QUICKI index were lower in the obese group. MBP, Tg/HDL-C ratio, HOMA, CRP, and leptin levels showed a positive and significant correlation and QUICKI a negative correlation with abdominal circumference, BMI, and FM. The Tg/HDL-C ratio correlated positively with MBP. The frequency of MS in the obese group was 69%. While Tg/HDL-C ratio, CRP, and leptin were higher and the values of QUICKI were lower in subjects with MS, it was the Tg/HDL-C ratio and the BMI that significantly explained the MS.

CONCLUSIONS

Obesity increases the cardiovascular risk in childhood. The Tg/HDL-C ratio could be a useful index in identifying children at risk for dyslipidemia, hypertension, and MS.

Circulating levels of high-sensitivity C-reactive protein and soluble markers of vascular endothelial cell activation in growth hormone-deficient adolescents

BACKGROUND/AIMS

Significant endothelial dysfunction as determined by lower flow-mediated vasodilation of the brachial artery was recently reported by us in growth hormone-deficient (GHD) adolescents. The circulating concentrations of markers of vascular endothelial cell and platelet activation and their relationship to inflammatory markers have not been previously evaluated in this group of patients.

OBJECTIVE

To assess the relationship between circulating levels of high-sensitivity C-reactive protein (CRP) and soluble markers of vascular endothelial cell activation in GHD adolescents.

DESIGN/METHODS

Twenty-eight GHD children on GH treatment with a chronological age of 15.7 +/- 2.6 years and 16 untreated GHD adolescents with a chronological age of 16.6 +/- 3.3 years were studied. Concentrations of CRP, as an inflammatory marker, were measured in all patients and the association between CRP and the fasting soluble markers of vascular endothelial cell activation intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin and P-selectin levels was evaluated. Sixteen healthy adolescents with a mean chronological age of 15.1 +/- 2.2 years served as controls.

RESULTS

CRP and P-selectin levels were significantly higher in untreated GHD adolescents than in treated GHD subjects or in healthy controls (p < 0.02), while VCAM-1 concentrations were increased in both untreated and treated GHD adolescents when compared to controls (p < 0.007). E-selectin and ICAM-1 levels were similar in all three groups. CRP was found to be associated with BMI (r: 0.62; p < 0.001), P-selectin (r: 0.43; p < 0.01), E-selectin (r: 0.27; p < 0.03), ICAM-1 (r: 0.23; p < 0.05) and VCAM-1 (r: 0.40; p < 0.001) concentrations in untreated GHD adolescents and with P-selectin (r: 0.88; p < 0.001) and E-selectin (r: 0.29; p < 0.01) in treated GHD subjects. A weak inverse association was observed in a subgroup of patients between brachial artery endothelium-dependent dilation and P-selectin (r: -0.56; p < 0.07).

CONCLUSIONS

Low-grade inflammation as manifested by increased circulating levels of CRP seems to be associated with the early activation of vascular endothelial cells in GHD adolescents.

Is testosterone and estrogen priming prior to clonidine useful in the evaluation of the growth hormone status of short peripubertal children?

AIM

To determine the usefulness of priming with gonadal steroids prior to growth hormone (GH) stimulation with clonidine in the evaluation of the GH status of short peripubertal children.

CHILDREN AND METHODS

Thirty-nine children, eight females and 31 males, were studied, with a mean chronological age of 12.37 +/- 2.24 years (range 8-15 years), mean bone age 9.58 +/- 2.21 years, Tanner stage 1-2, with height 134.12 +/- 11.27 cm (Ht-SDS -2.24 +/- 0.95), growth velocity (GV) 4.2 cm/yr (GV SDS -2.12 +/- 1.32) and an inadequate response to an initial GH stimulation test with clonidine (peak GH <10 microg/l). A second stimulation test with clonidine was performed in the same patients after gonadal steroid priming: 100 mg i.m. testosterone enanthate 5-8 days prior to GH stimulation in the males, and 1 mg estradiol valerate daily for 3 days in the females. GH, IGF-I, and testosterone/estradiol were measured before and after priming.

RESULTS

Twenty-one of 39 children (53.8%) increased their GH response to a level of >10 microg/l following priming with gonadal steroids. Mean peak GH after priming was 12.32 +/- 8.7 microg/l compared to a peak GH level of 4.87 +/- 2.72 microg/l prior to gonadal steroid priming (peak GH 17.42 +/- 8.46 microg/l in the responders versus 5.95 +/- 2.76 microg/l in the non-responders). Although a significant increase in GH and IGF-I concentrations was noted following priming, we were unable to find a correlation between IGF-I concentrations and peak GH following priming. IGF-I levels were not different in the responders and non-responders to clonidine following priming. There was no correlation between pubertal staging and testosterone/estradiol concentrations before priming with the peak GH after priming.

CONCLUSIONS

Priming with gonadal steroids significantly improves GH secretion following GH stimulation with clonidine and diminishes the possibility of a false diagnosis of GH deficiency. Gonadal steroid priming should therefore be considered in the evaluation of the GH status of short children close to or during the early stages of puberty.

Growth hormone deficiency, low levels of adiponectin, and unfavorable plasma lipid and lipoproteins

OBJECTIVE

To examine the impact of adolescent growth hormone deficiency (GHD) on circulating adiponectin levels and the relation between adiponectin, fasting insulin, plasma lipid, and lipoprotein levels.

STUDY DESIGN

Twelve children with GHD on GH treatment with a chronological age (CA) of 14.4 +/- 2.0 years and 12 untreated adolescents with GHD with a CA of 14.9 +/- 2.3 years were studied. Adiponectin concentrations were measured in all patients, and the association of adiponectin with fasting insulin, total, LDL, and HDL cholesterol, triglycerides, apolipoprotein A-1, and apolipoprotein B was evaluated. Twelve healthy adolescents served as control subjects.

RESULTS

Adiponectin levels were significantly lower in untreated GHD adolescents than in treated GHD subjects or in control subjects (P < .008). Total and LDL cholesterol, triglycerides, and Apo B concentrations were increased in untreated GHD adolescents, whereas HDL cholesterol levels were similar in all three groups. Insulin levels were significantly increased in treated GHD adolescents when compared with control subjects (P < .05) but similar to those with untreated GHD. Adiponectin was found to be negatively associated with body mass index, waist-to-hip ratio, and with Apo B, total cholesterol, triglycerides, and LDL cholesterol concentrations in untreated GHD adolescents, whereas a positive correlation between adiponectin and HDL cholesterol was noted in both untreated and treated GHD subjects. Adiponectin correlated inversely with fasting insulin levels in untreated and treated GHD adolescents.

CONCLUSIONS

GHD in adolescence is associated with low levels of adiponectin and with an unfavorable plasma lipid and lipoprotein profile. Our data suggest that treatment with GH may improve the abnormalities seen.

Coronary artery calcification, serum lipids, lipoproteins, and peripheral inflammatory markers in adolescents and young adults with type 1 diabetes

OBJECTIVE

To determine whether coronary artery calcification (CAC), elevated fasting lipids, and lipoproteins and peripheral inflammatory markers are present in insulin-dependent diabetic adolescents and young adults several years after diagnosis.

STUDY DESIGN

Hispanic insulin-dependent diabetics (n = 32) diagnosed a mean of 7.8 +/- 4.5 years ago (range, 3 to 16 years), with a mean glycosylated hemoglobin concentration at the time of the study of 8.8% +/- 2.3% and a mean chronological age of 16.1 +/- 4.4 years, were evaluated. Healthy patients (n = 15) with a chronological age (CA) of 15.2 +/- 2.2 years served as control subjects. CAC was assessed by multiple slice computed tomography, and total CAC score in Agatston units was calculated. Fasting lipids, C-reactive protein, apolipoprotein (Apo) A, Apo B, and metalloproteinase-9 (MMP-9) concentrations were measured in all subjects.

RESULTS

Neither adolescents with type 1 diabetes nor healthy control subjects presented with evidence of CAC. Fasting lipids, Apo A, Apo B, CRP, and MMP-9 concentrations were similar between diabetic subjects and control subjects. However, 34.4% and 25.0% of our type 1 diabetic subjects had elevated total and LDL cholesterol levels (>200 and >130 mg/dL, respectively), whereas 15.6% and 28.1% had elevated triglyceride and Apo B concentrations (>150 mg/dL and >100 mg/dL, respectively). In addition, 28.1% and 34.4% presented with elevated CRP and MMP-9 levels (>2 mg/L and >80 ng/mL, respectively). Total, LDL and HDL cholesterol, triglycerides, Apo B, CRP, and MMP-9 concentrations correlated positively with duration of the disease and with glycosylated hemoglobin levels.

CONCLUSIONS

Although the study adolescents with type 1 diabetes did not present any radiologic evidence of CAC at this stage of the disease, they remain a high-risk group for the development of microvascular and macrovascular artery disease, as risk factors such as elevated lipoproteins and proinflammatory markers are already present in a significant percentage of patients studied.

Relationship between different fasting-based insulin sensitivity indices in obese children and adolescents

OBJECTIVES

To evaluate insulin sensitivity from data obtained from baseline values and from an oral glucose tolerance test (OGTT) in normal and obese children and adolescents.

STUDY DESIGN

We recruited 89 children 4-10 years old and 82 adolescents 11-18 years old divided into moderately obese (Mod OB), severely obese (Severe OB), and non-obese (Non-OB) controls. We evaluated the relationship between four simple measures of insulin sensitivity: homeostatic model assessment (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), fasting glucose to insulin ratio (FGIR), and fasting insulin resistance index (FIRI), with an insulin sensitivity measure derived from the standard 2-hour OGTT, the composite whole body insulin sensitivity index (ISI Comp).

RESULTS

The strongest correlation was between QUICKI and ISI Comp and between FGIR and ISI Comp, (correlations [r] 0.81-0.85 in the Mod OB and 0.63-0.67 in the Severe OB). The relationship between HOMA-IR and ISI Comp and between FIRI and ISI Comp did not appear to be as strong (correlations [r] -0.36 and -0.53 in Mod OB and Severe OB, respectively). Moderately obese and severely obese children had fasting and 2-hour insulin levels 2-3 fold higher than the control group.

CONCLUSIONS

QUICKI and FGIR, are strongly correlated with OGTT measures of insulin sensitivity in children and adolescents with different degrees of obesity. These simple fasting-based indices may help the pediatrician identify patients at risk of developing insulin resistance.

Endothelial function, carotid artery intima-media thickness, epicardial adipose tissue, and left ventricular mass and function in growth hormone-deficient adolescents: apparent effects of growth hormone treatment on these parameters

OBJECTIVE

The purpose of this study was to determine whether GH-deficient (GHD) adolescents have abnormalities of cardiac and vascular function detectable during the teenage years.

DESIGN/METHODS

Ten GHD children on GH treatment with a chronological age (CA) of 14.6 +/- 1.7 yr and 12 untreated GHD adolescents with a CA of 15.0 +/- 3.0 yr were studied. Cardiac mass and function, carotid artery intima-media thickness, flow-mediated endothelium-dependent vasodilation (percent change from baseline diameter during hyperemia), and hyperemia-induced blood flow increase of the brachial artery (percent change from baseline) and epicardial adipose tissue were evaluated by echocardiography. Fourteen healthy adolescents served as controls.

RESULTS

Untreated GHD adolescents present with a reduced left ventricular mass when compared with controls (P < 0.05) and a lower flow-mediated endothelium-dependent increase in the diameter of the brachial artery during hyperemia than both controls and treated GHD subjects (P < 0.02), whereas their epicardial adipose tissue is significantly higher than that of healthy controls (P < 0.02). Interventricular septum thickness, posterior wall thickness, left ventricular ejection fraction, and carotid artery intima-media thickness were similar in all three groups. Hyperemia-induced blood flow increase was greater in treated GHD adolescents than both untreated subjects and controls (P < 0.001). Body mass index correlated positively with epicardial adipose tissue in all three groups and with carotid intima-media thickness in treated and untreated GHD adolescents.

CONCLUSIONS

GHD adolescents have a reduced left ventricular mass and vascular abnormalities manifested by lower flow-mediated endothelium-dependent vasodilation. These findings together with an increase in epicardial adipose tissue, a good indicator of abdominal/visceral fat, may contribute to an increased cardiovascular risk in the long term. An improvement in endothelial function and a reduction in arterial stiffness appear to occur after GH replacement.

Long-term outcome of growth hormone therapy in children and adolescents

Growth hormone (GH) has been available for more than 4 decades for the treatment of GH deficiency. Initially, GH was extracted from the pituitary glands of human cadavers, but its use was discontinued following the transmission of the Creutzfeldt-Jakob virus. After the development of recombinant GH (somatropin) in 1985, an 'unlimited' commercial source of GH has been available, allowing for the treatment of a large number of short GH-deficient and -sufficient children. Refinements in both the dosage and the frequency of administration of GH have allowed GH-deficient children to reach nearly normal final heights, although mostly they are still below their target heights. Decreased bone mineral densities and increased concentrations of fasting and postprandial lipids, coagulation factors, and several independent cardiovascular risk factors have been reported in GH-deficient children and adolescents and appear to improve with GH administration. The short-term administration of GH to mostly non-GH-deficient short children with Turner syndrome, chronic renal insufficiency (CRI), intrauterine growth retardation (IUGR), and idiopathic short stature (ISS) has resulted in increased growth velocities. In addition, the final height of patients with Turner syndrome and CRI appears to improve with the long-term administration of GH. Final height data are still lacking in adolescents with IUGR, but height standard deviation score and final height predictions appear to improve with therapy. Based on the incomplete and inconclusive available data, one must conclude that GH treatment of children with ISS cannot be advised. The use of GH at replacement doses in children with GH deficiency has resulted in rare and generally reversible adverse effects. The long-term administration of pharmacologic GH doses to short, mostly non-GH-deficient children must, however, still be viewed with caution, as long-term complications cannot as yet be fully evaluated. GH therapy must be individualized and should be limited only to children with severe short stature or a significantly decreased growth velocity, to children under considerable stress due to their short stature, and to patients in whom low GH or low insulin-like growth factor-1 secretion might be the rate-limiting factors for growth. The cost of the medication and the inconvenience of daily GH injections to otherwise mostly healthy short children must also be taken into account.

Metabolic abnormalities in growth hormone deficiency

Growth hormone has been implicated in the regulation of cardiovascular function and growth hormone deficiency (GHD) has been postulated to be one of the main factors responsible for the increased morbidity and mortality from cardiovascular disease in both young and older patients with childhood- and adulthood-onset GHD. Growth hormone also influences bone turnover and mineral deposition. Subjects with growth hormone deficiency have been shown to have an increased cardiovascular risk as manifested by elevated fasting and postprandial lipids and by increased body fat. In addition, premature atherosclerosis, decreased fibrinolytic activity, increased peripheral insulin resistance, abnormal cardiac structure and impaired cardiac performance have also been reported in this group of patients. Short and long term growth hormone treatment has been shown to exert beneficial effects on several of these parameters. While most of these abnormalities have been reported in adult GHD patients, metabolic changes in GHD children and adolescents have only recently begun to be investigated in more detail.

Female pseudohermaphroditism with phallic urethra in the offspring of a mother with an adrenal tumor

BACKGROUND

Female pseudohermaphroditism is a disorder in which 46,XX females with ovaries do not develop as normal women. This disorder is caused by overexposure of a female fetus to androgens during intrauterine life. We describe a masculinized female infant who was born to a mother who had virilizing signs.

PATIENT REPORT

The patient had a normally formed phallus and a completely fused scrotum. Baseline as well as stimulated adrenal hormones and testosterone values were in the normal range in the infant. No androgens were given to the mother during pregnancy. Serum 17-OHP, DHEA-S, and testosterone levels were all elevated in the mother. Imaging studies revealed a tumor mass over the left kidney pole. Histologically it was an adrenal tumor.

CONCLUSIONS

Although a maternal adrenal tumor is a rare cause of female pseudohermaphroditism, the physician must bear this in mind when confronted with a newborn or infant with 46,XX karyotype and cryptorchidism with a phallic urethra.

Peripheral inflammatory and fibrinolytic markers in adolescents with growth hormone deficiency: relation to postprandial dyslipidemia

OBJECTIVE

To determine whether peripheral inflammatory and fibrinolytic markers are elevated in growth hormone-deficient (GHD) adolescents and associated with increased postprandial lipoproteins.

STUDY DESIGN

Fifteen GHD children on GH treatment with a chronologic age of 12.7 +/- 2.5 years and 10 untreated GHD adolescents with a chronologic age of 13.0 +/- 2.6 years were studied. Triglycerides (TG), C-reactive protein (CRP), fibrinogen, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were measured in the fasting state and 4 hours after ingesting a high-fat meal; 15 healthy adolescents served as controls.

RESULTS

Fasting and postprandial TG of untreated GHD children were higher than those in treated subjects and healthy controls. Fasting TNF-alpha, CRP, and fibrinogen concentrations of untreated GHD adolescents were higher than those in healthy controls, but similar to those of GH-treated GHD adolescents. Although fibrinogen levels increased after a high-fat meal in GHD adolescents, CRP, TNF-alpha, and IL-6 concentrations did not increase further. Fasting and postprandial TG of untreated GHD adolescents were positively associated with fasting and postprandial CRP, and with postprandial TNF-alpha and IL-6 concentrations. Fasting TG also correlated positively with fasting fibrinogen concentrations in untreated and treated GHD adolescents.

CONCLUSIONS

The pronounced inflammatory response seen in GHD adolescents seems to be associated with the presence of elevated levels of fasting and postprandial TG, which may result in an increased susceptibility for premature atherosclerosis.

Decreased final height of children with growth deceleration secondary to poor weight gain during late childhood

Eighteen healthy, short children with normal growth during most of their childhood were evaluated after a sustained fall in weight and reduced linear growth. Growth was followed after nutritional counseling until final height. This report demonstrates the need for an appropriate-for-age weight gain in growing children as a relatively minor but prolonged caloric restriction, leading to a sustained fall in weight centiles, will affect growth velocities long term and may lead to reduced final heights.

Accelerated versus slowly progressive forms of puberty in girls with precocious and early puberty. Gonadotropin suppressive effect and final height obtained with two different analogs

OBJECTIVES

To distinguish which children with precocious puberty (PP) and early puberty (EP) should be treated and which followed without therapy. To determine the effect of GnRH analog treatment on the final height of treated patients and compare the effect of two different analogs on gonadotropin suppression and final height.

STUDY DESIGN

Sixteen females with PP or EP with a mean chronological age (CA) of 8.8 +/- 1.4 years and a mean bone age (BA) of 10.8 +/- 1.3 years were treated for a mean of 2.7 +/- 1.0 years with a GnRH analog (triptorelin or leuprolide acetate; group A), while 21 girls with a mean CA of 8.5 +/- 1.0 years, a mean BA of 9.7 +/- 1.4 years and a predicted adult height of >155 cm were followed without therapy (group B). Criteria for treatment were one of: a. predicted adult height (PAH) of <155 cm initially or at any time during follow up; b. PAH over 155 cm with a dramatic decrease in PAH over a 6-month follow-up period; c. advanced and rapidly progressing breast development for age (Tanner 3 before the age of 9 years).

RESULTS

GnRHa therapy suppressed gonadotropins in group A, while gonadotropins increased gradually in group B. Height velocity (HV) decreased in group A, while it remained accelerated in group B; BA increased a mean of 1.7 +/- 0.5 years in group A and 3.2 +/- 0.3 years in group B. This resulted in a height increase in group A from a baseline PAH of 153.7 +/- 1.2 cm to a final height (FH) of 160.9 +/- 4.0 cm (p <0.001), clearly above their target height (TH) of 157.7 +/- 4.2 cm. The height of group B children did not change over time (164.1 +/- 4.1 cm before therapy and 166.0 +/- 6.0 cm at FH), both above their TH. The mean leuprolide acetate dose utilized in this study decreased during treatment, while both the initial and final triptorelin dose remained unchanged. Adequate gonadotropin suppression (peak level of LH and FSH of <2 IU/l after i.v. GnRH stimulation) was noted with both leuprolide acetate and triptorelin, although LH suppression was slightly more pronounced with triptorelin. BA advanced 1.8 +/- 0.4 years during leuprolide acetate treatment and 1.5 +/- 0.3 years with triptorelin, so that FH increased a mean of 5.5 +/- 1.3 cm with leuprolide acetate and 8.7 +/- 2.2 cm with triptorelin.

CONCLUSIONS

PAH of <155 cm before or during therapy, PAH of >155 cm with a dramatic decrease in predicted height over a 6-month follow-up period and/or advanced and rapidly progressing breast development in girls with PP or EP were useful parameters in deciding which patients to treat. GnRHa therapy suppressed gonadotropins, HV and bone maturation in children with an accelerated form of PP or EP, resulting in a significant height increase. Final height remained stable over time in untreated patients. Adequate gonadotropin suppression was noted with both analogs, although with the doses of analog used in our study, LH and BA suppression were more pronounced with triptorelin, resulting in a larger height gain.

Cardiovascular Risk of Young Growth-Hormone-Deficient Adolescents

OBJECTIVE

To determine whether postprandial lipids, coagulation factors and homocysteine levels are abnormal in young growth hormone (GH)-deficient (GHD) adolescents.

METHODS

Fifteen GHD adolescents on GH replacement were studied. Ten untreated GHD adolescents and 15 healthy subjects served as controls. Fasting lipids, lipoprotein(a), fibrinogen, plasminogen activator inhibitor-1, homocysteine, folate and vitamin B12 levels were measured. Cholesterol and triglycerides were measured 4 h after a high fat meal.

RESULTS

Fasting and postprandial triglycerides and homocysteine levels of untreated GHD patients were increased compared to those of GH-treated GHD subjects and healthy controls; fibrinogen concentrations were elevated in both treated and untreated adolescents.

CONCLUSIONS

GHD adolescents present an abnormal fasting and postprandial lipid profile. In addition, the increased fibrinogen and homocysteine levels are suggestive of the accumulation of cardiovascular risk factors early on in life.

Molecular analysis in Turner syndrome

OBJECTIVE

The frequency of Y-chromosome material is high in Turner syndrome (TS), but the ocurrence of gonadoblastoma seems to be low. We performed a study to evaluate whether DNA analysis might be a useful tool in the evaluation of patients with TS.

SUBJECTS

Unrelated patients with TS (n = 52) of Venezuelan mestizo ethnic origin were diagnosed by cytogenetic analysis as having TS.

METHODS

Clinical assessment, karyotyping, endocrine evaluation, fluorescence in situ hybridization, and polymerase reaction chain analysis of the Y-chromosome loci.

RESULTS

We found that 7.69% (4 of 52) patients with TS had Y-chromosome material. A low occurrence of gonadoblastoma was also found (2 of 52 [3.85%]). Two patients showed a 45,X/46,XY karyotype, and gonadoblastoma in the gonadal biopsy specimen was not found. Two patients had no Y chromosome on initial karyotype; they were positive on lymphocyte DNA to Y-sequences specific. Both patients (45,X) had bilateral gonadoblastoma. The four patients with Y-chromosome material in peripheral blood lymphocytes had Y-chromosome sequences on gonadal DNA. Fluorescence in situ hybridization confirmed their Y-chromosome origin.

CONCLUSIONS

Our results suggest that the detection of Y-chromosome material should be carried out in all patients with TS and not be limited to patients with TS with cytogenetically identifiable Y chromosome and/or virilization.

The effect of short- and long-term growth hormone treatment on bone mineral density and bone metabolism of prepubertal children with idiopathic short stature: a 3-year study

OBJECTIVE

We recently reported that children with idiopathic short stature (ISS) have decreased lumbar spine bone mineral density (BMD) that increases after 1 year of GH therapy. The aim of this study was to confirm these short-term results and to evaluate the effect of long-term GH therapy on the BMD of children with ISS.

PATIENTS AND DESIGN

We treated a group of 16 short, slow-growing but otherwise healthy non-GH-deficient prepubertal children (8 girls and 8 boys) with a chronological age of 9.5 +/- 0.9 years, a bone age of 8.1 +/- 1.2 years and a height of 124.3 +/- 6.3 cm (height-SDS of -2.1 +/- 0.6) with GH at a dose of 0.1 IU/kg/day for 3 consecutive years.

MEASUREMENTS

Height was determined at 3-month intervals and annual growth velocities were calculated. Bone ages and BMD were measured every 12 months by dual-energy X-ray absorptiometry, as were serum concentrations of the carboxy-terminal propeptide of type 1 collagen (PICP) and the carboxy-terminal cross-linked telopeptide of type 1 collagen (ICPT).

RESULTS

Growth velocity increased from 4.0 +/- 0.8 cm/year to 8.7 +/- 1.5 and 8.0 +/- 1.7 cm/year at 12 and 36 months of GH therapy, respectively, while height-SDS improved from -2.1 +/- 0.6 to -1.6 +/- 0.4 after 36 months of GH (P < 0.0001). Baseline lumbar spine BMD was decreased when compared to that of a control group of healthy children paired for gender, bone age and height (0.640 +/- 0.08 g/cm2vs. 0.730 +/- 0.08 g/cm2; P < 0.003). Lumbar spine BMD increased after 1 year of GH from 0.640 +/- 0.08 to 0.749 +/- 0.08 g/cm2 (P < 0.05), reaching levels similar to that of controls followed for 1 year without therapy (0.749 +/- 0.04 g/cm2vs. 0.760 +/- 0.08 g/cm2). During this period lumbar spine BMD increased 14.5% in the ISS subjects and 3.9% in the controls. Over the following 2 years of GH therapy the lumbar spine BMD of our ISS patients increased at a rate similar to that of the control population, so that after 3 years of consecutive GH therapy the lumbar spine BMD of ISS children was comparable to that of the controls (0.784 +/- 0.12 g/cm2vs. 0.785 +/- 0.09 g/cm2). Femoral neck BMD of our patients was similar to that of the controls at baseline and at 36 months. Following 1 year of GH treatment serum concentrations of PICP increased from 229.6 +/- 63.5 to 358.6 +/- 87.9 micro g/l, while levels of ICTP increased from 9.6 +/- 5.9 to 13.7 +/- 2.1 micro g/l. After 36 months of GH therapy, PICP and ICTP values had decreased to 303.3 +/- 67.2 micro g/l and 11.3 +/- 3.3 micro g/l, respectively, and were no longer significantly different from baseline.

CONCLUSIONS

Children with ISS have decreased lumbar spine BMD, which normalized after 1 year of GH. Over the next 2 years of therapy lumbar spine BMD increased at a normal rate, so that after 3 consecutive years of GH the lumbar spine BMD of children with ISS was similar to that of controls. Bone turnover increased with treatment as indicated by a rise in bone formation and bone resorption markers.

Is insulin-like growth factor-1 monitoring useful in assessing the response to growth hormone of growth hormone-deficient children?

OBJECTIVE

To assess the relationship between insulin-like growth factor-1 (IGF-1), the growth hormone (GH) dose utilized to treat GH-deficient children and the changes noticed in height-standard deviation score (H-SDS) and height velocity (HV).

STUDY DESIGN

We studied 24 prepubertal GH-deficient patients with a mean age of 10.5 +/- 1.8 years and a mean bone age (BA) of 8.4 +/- 2.1 years. H-SDS for chronologic age (CA) and BA before therapy were -2.6 +/- 0.8 and -1.2 +/- 0.8, whereas height velocity (HV)-SDS was -1.1 +/- 1.5. Serum IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels were measured before, after 6 and 12 months of GH, and correlated with the GH dose used. Based on the increment of IGF-1 used during treatment, patients were divided into 2 groups: G1 (>1 SDS) and G2 (<1 SDS). HV-SDS and interval height increases were analyzed.

RESULTS

HV-SDS, as well as H-SDS for CA and BA during the first year of treatment, were significantly greater than before therapy. IGF-1 SDS increased significantly during the first 6 months of therapy (P <.0003), but increased no further at 12 months despite the use of a higher GH dose (0.1 vs 0.14 IU/kg/day), whereas IGFBP-3 SDS increased at both 6 and 12 months. There was no correlation between the GH dose used and IGF-1 and IGFBP-3 levels. When patients were divided according to their IGF-1 increment during therapy, a significant increase in H-SDS for BA and in HV-SDS was noted only in group 2.

CONCLUSIONS

The increment in IGF-1 SDS during therapy did not correlate with the interval height increase. IGF-1 measurement may be helpful in monitoring compliance and safety, but seems to be less useful in adjusting the GH dose needed to treat prepubertal GH-deficient children.

Cardiac mass and function, carotid artery intima-media thickness and lipoprotein (a) levels in children and adolescents with type 1 diabetes mellitus of short duration

OBJECTIVE

To evaluate cardiac mass and function, carotid intima-media thickness, and serum lipid and lipoprotein (a) (Lpa) levels in children and adolescents with type 1 diabetes mellitus (DM) of short duration.

BACKGROUND

Diabetes mellitus has been found to be an important risk factor for macrovascular disease in adults. Increased serum lipids and Lpa levels have been reported in adolescents with type 1 DM; atherosclerotic vascular lesions involving a combination of fatty degeneration and vessel stiffening of the arterial wall and myocardial involvement impairing diastolic function may be present in adolescents and young adults with type 1 DM.

DESIGN/METHODS

Twenty children and adolescents (10 males, 10 females) diagnosed with type 1 DM before 3.4 +/- 3.3 years with a mean age of 11.9 +/- 3.6 years were studied; their HbA1c levels were 8.0 +/- 1.9%. Twenty healthy non-diabetic controls, 10 males and 10 females, aged 12.1 +/- 3.4 years, matched for height and weight, participated in the study. Fasting blood samples were obtained for lipid and Lpa analysis. Patients underwent transthoracic M-mode and two-dimensional echocardiographic evaluation for measurement of left atrial and ventricular dimensions and left ventricular (LV) wall thickness and mass. Stroke volume and cardiac output were measured using pulsed Doppler echocardiography; carotid intima-media thickness was measured using high-resolution mode B ultrasound.

RESULTS

Interventricular septal thickness (7.1 +/- 1.8 vs 7.0 +/- 1.5 mm), LV posterior wall thickness (7.1 +/- 1.4 vs 7.5 +/- 2.0 mm) and LV mass after correction for body surface area (70.6 +/- 27.4 vs 70.7 +/- 18.0 g/m2) were similar in patients and controls. Similarly, the LV ejection fraction at rest was similar in patients and controls (69.9 +/- 2.3 vs 70.0 +/- 0.6%), as were pulmonary venous flow velocities (0.56 +/- 0.09 vs 0.55 +/- 0.10 m/s for diastolic peak velocity, 0.54 +/- 0.08 vs 0.50 +/- 0.09 m/s for systolic peak velocity and 0.17 +/- 0.07 vs 0.19 +/- 0.05 m/s for atrial reversal filling). Carotid intima-media thickness (0.60 +/- 0.02 and 0.59 +/- 0.02 mm for the right and left carotid artery) was similar to that of controls (0.60 +/- 0.03 and 0.61 +/- 0.02 mm for the right and left carotid artery). Low density lipoprotein cholesterol and Lpa levels were increased in patients compared to controls (113.2 +/- 26.0 mg/dl and 20.1 +/- 11.7 mg/dl in patients vs 90.4 +/- 14.3 mg/dl and 9.8 +/- 2.9 mg/dl in controls; p <0.01), while total cholesterol, HDL cholesterol and serum triglyceride concentrations were similar to those in controls.

CONCLUSIONS

Although children and adolescents with type 1 DM seem not to show alterations in cardiac mass and function or early atherosclerotic changes in the first few years after diagnosis, their cardiovascular risk is increased as they present with dyslipidemia at an early stage of the disease.

Decreased bone mineral density and bone formation markers shortly after diagnosis of clinical type 1 diabetes mellitus

We recently demonstrated that children with type 1 diabetes mellitus (DM) have decreased lumbar spine bone mineral density (BMD) as early as four years after clinical diagnosis of the disease. In order to determine whether osteopenia is already present in patients very early on after diagnosis of clinical DM, we evaluated the bone mineral status of a group of newly diagnosed children (5.8 +/- 1.5 mo after diagnosis). We studied 23 prepubertal children (7 M, 16 F) with a mean chronological age of 9.5 +/- 2.2 yr and a mean glycosylated hemoglobin of 8.9 +/- 2.4%. Lumbar spine and femoral neck BMD were measured by dual X-ray absorptiometry, while bone turnover was assessed by the determination of the serum concentration of the carboxy-terminal propeptide of type I collagen (PICP) and the carboxy-terminal cross-linked telopeptide of type I collagen (N-telopeptide). Results were compared to those of age, height, and pubertal status matched controls. Lumbar spine BMD Z-scores were decreased in patients compared to controls (Z-scores of -0.89 +/- 1.2, with 10 of 22 patients showing values >1 SD below the mean). When lumbar spine Z-scores were analyzed in those patients with <3 months or > or =3 months since diagnosis of DM a significant difference was noticed between groups (-0.648 +/- 1.12 vs -1.267 +/- 1.17; p <0.02). No significant differences were noted in femoral neck BMD and total BMD between groups. Serum PICP levels were decreased when compared to controls (233.6 +/- 39.3 vs 375.9 +/- 50.7 microg/l; p <0.002), while serum N-telopeptide concentrations, although increased, were not significantly different (9.3 +/- 1.3 vs 5.7 +/- 1.5 microg/l). In summary, early on after the diagnosis of type 1 DM, children present with decreased lumbar spine BMD and decreased bone formation markers.

Cardiac mass and function, carotid artery intima-media thickness, and lipoprotein levels in growth hormone-deficient adolescents

The objective of our study was to evaluate whether cardiac mass and function, carotid artery intima-media thickness, and serum lipid and lipoprotein(a) levels are abnormal in adolescents with GH deficiency. Young adults with childhood-onset and adulthood-onset GH deficiency have been found to have a higher cardiovascular risk, as manifested among other factors by reduced left ventricular mass, impaired systolic function, significant increase in arterial intima-media thickness, and dyslipidemia. Twelve adolescents (seven males and five females) with GH deficiency (10 idiopathic and 2 organic), with an age of 14.2 +/- 2.8 yr and a height of 140.6 +/- 17.9 cm (height SD score, -2.6 +/- 0.3), were studied. Six children had received GH in the past but were off therapy for several years, whereas six patients had never been treated with GH. Fasting blood samples were obtained for serum lipids and lipoprotein(a) analysis. Patients underwent transthoracic M-mode and two-dimensional echocardiographic evaluation for measurement of interventricular septal thickness, left ventricular posterior wall thickness, and left ventricular mass, as well as left ventricular ejection fraction at rest and pulmonary venous flow velocities; carotid artery intima-media thickness was measured using high-resolution mode B ultrasound. Seven GH-deficient (GHD) adolescents on GH at the time of the study and 19 healthy adolescents, all comparable for age, pubertal status, height, weight, blood pressure, and pulse, participated in this study as controls. Interventricular septal thickness (6.5 +/- 1.3 vs. 7.0 +/- 1.5 mm), left ventricular posterior wall thickness (7.0 +/- 1.8 vs. 7.5 +/- 2.0 mm), and left ventricular mass after correction for body surface area (71.2 +/- 21.8 vs. 70.7 +/- 18.0 g/m(2)) were similar in untreated GHD patients and healthy controls. Similarly, the left ventricular ejection fraction at rest was similar in untreated GHD subjects and controls (70.0 +/- 0.7 vs. 70.0 +/- 0.6%), as were the pulmonary venous flow velocities (0.54 +/- 0.16 vs. 0.55 +/- 0.10 m/s for diastolic peak velocity; 0.51 +/- 0.16 vs. 0.50 +/- 0.09 m/s for systolic peak velocity; and 0.19 +/- 0.06 vs. 0.19 +/- 0.05 m/s for atrial reversal filling). Carotid artery intima-media thickness (0.60 +/- 0.02 mm and 0.59 +/- 0.02 mm for the right and left carotid arteries, respectively) was also normal in our untreated GHD patients when compared with healthy controls. In addition, all echocardiographic measurements were similar in GHD subjects on or off GH at the time of the study. Low-density lipoprotein cholesterol levels were increased in untreated GHD patients when compared with healthy controls (3.17 +/- 0.70 vs. 2.33 +/- 0.36 mmol/L; P < 0.01), whereas total cholesterol, high-density lipoprotein cholesterol, and triglyceride concentrations were similar to that of controls. Total cholesterol levels were increased in our untreated GHD adolescents when compared with GHD subjects receiving GH therapy at the time of the study, while low-density lipoprotein cholesterol and triglyceride levels were also elevated, although not significantly. Lipoprotein(a) levels were elevated in untreated GHD adolescents when compared with healthy controls, and untreated GHD subjects had higher lipoprotein(a) concentrations than GH-treated patients. GHD adolescents, regardless of whether or not they received GH therapy, do not seem to show alterations in cardiac mass and function or early atherosclerotic changes. They must, however, be followed carefully because they already present cardiovascular risk factors such as dyslipidemia, which may increase their cardiovascular morbidity over time.

Acipimox, a nicotinic acid analog, stimulates growth hormone secretion in short healthy prepubertal children

Recent studies in adult volunteers have demonstrated that the free fatty acid reduction induced by acipimox, a nicotinic acid analog, stimulated GH secretion per se and enhanced in an additive manner the GH secretion elicited by such different stimuli as pyridostigmine, GHRH and GHRP-6. In order to evaluate whether acipimox administration stimulates GH secretion in prepubertal children, we administered a single oral dose of acipimox (100 mg for children weighing <30 kg and 200 mg for those >30 kg) to 14 healthy prepubertal children with a mean age of 8.2 +/- 1.9 years, a mean bone age of 6.2 +/- 3.0 years, growing along the 5-10th percentiles, and with normal thyroid function and IGF-I levels. Acipimox administration elicited a sustained increase in GH from a mean baseline level of 0.6 +/- 0.4 to 6.7 +/- 2.4 microg/l at the end of the test (p<0.05), with a mean GH peak of 10.5 +/- 3.5 microg/l. GH release was delayed so that peak GH levels were achieved 180 minutes after acipimox administration. In order to determine whether acipimox was capable of enhancing the GH secretion elicited by levodopa (L-Dopa), we administered either oral L-Dopa (250 mg for children weighing <30 kg and 500 mg for those >30 kg) or oral acipimox plus L-Dopa to the same children on different days. GH concentrations increased in a similar fashion following either of these tests (from a baseline level of 1.2 +/- 0.4 and 0.7 +/- 0.4 microg/l to 8.4 +/- 2.7 and 9.3 +/- 2.9 microg/l at the end of the test (p<0.001), with peak GH concentrations of 13.1 +/- 4.1 and 11.8 +/- 3.3 microg/l after L-Dopa or acipimox plus L-Dopa, respectively). Although the peak GH concentrations obtained after the combined administration of acipimox plus L-Dopa were similar to those obtained after either acipimox or L-Dopa administration, a larger number of our patients reached a GH cut-off point of >7 microg/l following combined therapy than with either stimulus alone (13/14 patients with combined therapy and 10/14 with acipimox alone). No side effects other than mild facial flushing were noted after acipimox administration. These results indicate that: 1) following the administration of a single oral dose of acipimox, significant GH secretion was elicited in healthy short prepubertal children; 2) the combined administration of acipimox plus L-Dopa did not, however, enhance the GH secretion of this group of children; 3) acipimox was well tolerated with minimal side effects; and 4) further studies in both GH sufficient and GH deficient children are necessary to evaluate acipimox's usefulness in assessing GH reserve.

Growth velocity, final height and bone mineral metabolism of short children treated long term with growth hormone

Since human recombinant growth hormone (GH) became available a large number of short GH deficient and GH-sufficient children have been treated with growth hormone. Growth hormone deficient patients have been followed to final height and several studies have shown that even when treated with GH from very early on in life they tend to end up shorter than their target height. There is, however, a clear increase in their growth velocities particularly during the first 4-5 years of GH therapy so that patients end up with a height-SD score of aproximately -0.8. Recent studies have demonstrated decreased bone mineral densities (BMD) in children with growth hormone deficiency, both by areal and volumetric analysis. Therapy with growth hormone clearly increases their BMD with an increase in bone formation markers, as will be reviewed in detail. Growth hormone therapy of non-growth hormone deficient short children has increased their growth velocity short term, particularly in girls with Turner's syndrome and in children with chronic renal insuficiency. Recent final height data by Rosenfeld et al. and by Swedish and Dutch groups have demonstrated a gain of 8-12 cm in girls with Turner's syndrome treated with GH or with a combination of GH and oxandrolone. Neely et al. and we have demonstrated that growth hormone treated prepubertal age girls and adolescents with Turner's syndrome have normal BMD and Shaw et al. has suggested that they have normal BMD despite GH or estrogen therapy. However, we found the BMD of a group of previously GH treated young women with Turner's syndrome on estrogen replacement to be decreased compared to both age and gender matched controls and to controls of the same weight and pubertal status. Growth hormone therapy increases the growth velocity and the final height of children with chronic renal insuficiency, particularly in prepubertal children treated with GH before dialysis. We have demonstrated how the BMD of these patients, which at baseline is low when compared to healthy age matched controls, but normal when compared to height and bone age matched controls, increases with growth hormone treatment significantly, moreso than in untreated uremic controls or in untreated healthy controls paired for height and bone age. Short, slowly growing, non growth hormone deficient patients (idiopathic short stature) have been treated for prolonged periods of time with GH. We and others have demonstrated a clear increase in their growth velocity short term, but improvement of their final height remains unclear and controversial. After 4-8 years of GH treatment, Hintz et al. have found a 5-6 cm increase in final height compared to the predicted adult height before beginning therapy, but most patients did not reach their target heights. Other studies, however, have found no improvement in final height and Kawai et al. even suggests that GH therapy diminishes the final height of treated children due to an earlier puberty and a shorter pubertal growth spurt. We, have found decreased BMD in children with idiopathic short stature when compared to controls of their same height and bone age with a significant increase in BMD following 12 months of GH and with an increase in bone turnover as measured by bone formation and resorption markers. Recent short term studies in patients with hypophosphatemic rickets and osteogenesis imperfecta treated with rhGH have also yielded similar results which will be specified in the review. Some 10-20% of children born with intrauterine growth retardation (IUGR) end up short and we had already demonstrated 20 years ago how 2 years of GH therapy were capable of increasing their growth velocities significantly with an improvement of their height-SD scores. Recent studies mainly from Europe have corroborated this data long term, so that IUGR children have been shown by de Zegher et al. to increase their growth velocities and their height for age after 6 years of treatment, entering into the low normal centiles of their growth curves for age. Long term studies of these children to final height will be necessary to determine the usefulness and safety of this form of therapy.

Multiple endocrine abnormalities in a child with Blackfan-Diamond anemia and hemochromatosis. Significant improvement of growth velocity and predicted adult height following growth hormone treatment despite liver damage

We evaluated a short, prepubertal 13.9 year-old boy with Blackfan-Diamond anemia and significant liver iron stores due to multiple blood transfusions and found him to have several endocrine abnormalities, including hypothyroidism, hypoparathyroidism, primary and secondary hypogonadism and IGF-I insufficiency. Growth velocity was poor despite treatment with levothyroxine, calcitriol, calcium and aggressive therapy with chelating agents. After 25 months of treatment with rhGH his growth velocity, height for age and PAH increased significantly, suggesting a degree of sensitivity to GH despite his liver damage.

Decreased bone mass despite long-term estrogen replacement therapy in young women with Turner's syndrome and previously normal bone density

OBJECTIVE

To determine whether young women with Turner's syndrome who had normal bone mineral density (BMD) before the induction of puberty maintain normal BMD in young adulthood.

DESIGN

Controlled clinical study.

SETTING

A private hospital clinical research setting.

PATIENTS

Young women with Turner's syndrome in Tanner stage V of puberty with previously normal BMD.

INTERVENTIONS

Oral conjugated estrogens and progesterone acetate were administered continuously for a mean (+/-SD) of 4.1+/-1.0 years. Bone mineral densities and blood samples were evaluated.

MAIN OUTCOME MEASURE(S)

The BMD of the lumbar spine and the femoral neck was determined during young adulthood. The change in BMD over the previous 6 years also was evaluated. Serum concentrations of the carboxy-terminal propeptide of type 1 collagen and of the carboxy-terminal cross-linked telopeptide of type 1 collagen were measured.

RESULT(S)

The BMD of the lumbar spine was reduced significantly in our patients. There was no change in the BMD of the femoral neck or lumbar spine over a period of 6.1 years. Concentrations of the carboxy-terminal propeptide of type 1 collagen were decreased, whereas concentrations of the carboxy-terminal cross-linked telopeptide of type 1 collagen were increased.

CONCLUSION(S)

Young women with Turner's syndrome do not attain normal peak bone mass even when estrogen replacement therapy is begun in adolescence. Their low BMD seems to be due to decreased bone formation and increased bone resorption.

Decreased trabecular bone mineral density in children with idiopathic short stature: normalization of bone density and increased bone turnover after 1 year of growth hormone treatment

Patients with growth hormone (GH) deficiency have impaired bone mineral metabolism; treatment with GH leads to an improvement in their bone mineral density (BMD). The effect of GH on the BMD of children with idiopathic short stature is unknown. We studied 14 short, slowly growing, otherwise healthy, prepubertal children without GH deficiency (7 girls and 7 boys) with a chronological age of 10.9 +/- 1.4 years, bone age of 8.8 +/- 1.5 years, and height of 127.8 +/- 8.5 cm (height SD score of -2.2 +/- 0.5). Growth velocity increased from 3.9 +/- 1.1 cm/y to 8.0 +/- 1.9 cm/y, and height SD score improved from -2.2 +/- 0.5 to -1.8 +/- 0.5 after 12 months of GH treatment (P <.007 and P <.001, respectively). Baseline lumbar spine BMD was decreased when compared with that of a control group of children matched for bone age and height (0.645 +/- 0.09 g/cm(2) vs 0.730 +/- 0.08 g/cm(2); P <.003). Lumbar spine BMD increased in subjects with ISS after 1 year of GH treatment from 0.645 +/- 0.09 g/cm(2) to 0.808 +/- 0.04 g/cm(2) (P <.05), reaching levels similar to those of control subjects, followed up without therapy (0.808 +/- 0.04 g/cm(2) vs 0.760 +/- 0.08 g/cm(2)); lumbar spine BMD increased 25.3% in the subjects with ISS and 4.1% in the control subjects. Femoral neck BMD did not change during treatment. Serum concentrations of the carboxy-terminal propeptide of type 1 collagen increased from 231.6 +/- 65.5 microg/L to 351.6 +/- 87.2 microg/L, and levels of the carboxy-terminal cross-linked telopeptide of type 1 collagen increased from 9.9 +/- 5.9 microg/L to 13.9 +/- 2.4 microg/L. Children with ISS have decreased lumbar spine BMD, which increases with GH therapy, reaching levels similar to those of control subjects. Bone turnover increased as indicated by a rise in bone formation and bone resorption markers.

Final height after combined growth hormone and gonadotrophin-releasing hormone analogue therapy in short healthy children entering into normally timed puberty

OBJECTIVE

Combined gonadotrophin-releasing hormone analogue and recombinant human growth hormone therapy has been used in an attempt to improve the final height of short non-GH deficient adolescents with normally timed puberty; its use, however, is still controversial as only short-term studies in a very limited number of patients have been undertaken, with either improvement in height prognosis or no beneficial effect on predicted growth. We have treated a group of extremely short healthy children with very low predicted adult heights entering into normally timed puberty with combined therapy, in order to determine whether we could improve their final height above their pretreatment predicted adult height.

PATIENTS

We treated 10 healthy adolescent short children (7 girls and 3 boys) simultaneously for 30.0 +/- 5.2 months with the GnRH analogue leuprolide acetate (0.3 mg/kg im every 28 days) and with rhGH (0.1 U/kg/day, sc, 6 days a week). The mean chronological age of our patients was 11.8 +/- 1.3 years, with a mean bone age of 11.2 +/- 0.9 years, height of 128.9 +/- 7.5 cm (-2.4 +/- 0.4 SD below the mean) and a predicted adult height of 150.7 +/- 9.8 cm; they were all in Tanner stage II-III of puberty. Ten healthy short children (7 girls and 3 boys) in the early stages of puberty with a mean chronological age of 11.4 +/- 1.0 years, a mean bone age of 11.0 +/- 0.8 years, height of 128.9 +/- 7.8 cm (-2.3 +/- 0.4 SD below the mean) and a mean adult predicted height of 151.8 +/- 10.1 cm served as controls and were simultaneously followed without therapy for the same study period.

MEASUREMENTS

Height and pubertal status were followed every 3 months during combined therapy and until final height of our patients was reached; bone ages were obtained every 6 months. Growth hormone deficiency was ruled out in all our subjects prior to beginning of the study by a normal response to oral clonidine and normal IGF-1 levels. Basal serum testosterone and/or oestradiol levels, as well as LH and FSH following administration of LH-releasing hormone were obtained before treatment and after 6 weeks and 4 months of combined therapy and every 6 months thereafter. Routine biochemistry as well as thyroid function tests were obtained at each visit.

RESULTS

Combined treatment resulted in an interruption of pubertal development with a suppression of gonadal steroids and of the LH response to LH-releasing hormone. Growth velocity decreased from 6.5 +/- 1.6 cm/year before treatment to 5.5 +/- 1.5 cm/year and 3.9 +/- 1.3 cm/year during the first and second year of treatment (P < 0.02 and P < 0.05, respectively) resulting in a height Z score reduction, declining from -2.4 +/- 04 to -2.6 +/- 0.7 SD. Bone age maturation declined averaging 0.75 bone age year/year of treatment but height SDS for bone age declined from -1.7 +/- 0.7 to -2.2 +/- 0.5 at the end of the second year of therapy with no improvement in predicted adult height (150.7 +/- 9.8 cm before and 150.0 +/- 8.0 after 2 years of therapy). After discontinuing treatment growth velocity did not improve and bone maturation advanced more rapidly (averaging 2.0 +/- 0.4 year/year of follow up) and the mean final height of our patients was 151 +/- 2.4 cm (-2.6 +/- 0.6 SD below the mean) which was not greater than the mean pretreatment predicted adult height and well below their target height; these results were also similar to those of the control population in whom the predicted adult height at the beginning of the study and after 2 years of follow up, was not different from their final height and well below their target height.

CONCLUSIONS

We conclude that combined rhGH and GnRH analogue therapy in short adolescents with normally timed puberty does not contribute to increase their final height above their pretreatment predicted adult height; we can therefore not recommend this form of therapy for this group of patients given the poor results obtained, as well as the cost of these medications and the

[High- and low-risk molecular sequences in autoimmune diseases. An analysis of type I diabetes in Latin America]

Type I diabetes is an autoimmune and a polygenic disease, in which MHC-class II genes contribute to 48% of the disease. The aim of the present study, is to provide a guideline to understanding the molecular association of these genes, through the immunogenetic analysis of 3 Latin american mestizo populations. We included 606 individuals, 349 patients with DMDI and 257 healthy controls coming from 3 geographical areas: Mexico City, Mexico; Caracas, Venezuela and Medellin, Colombia. The results clearly indicate that in mestizo groups, the diabetogenic haplotypes are from mediterranean ancestry, while protection is due to Amerindian genes. It was demonstrated that the relevant sequences for IDDM expression are located to DRB1 and DQB1 loci with a minimal contribution of DQA1 residues. The sequences determining peptide recognition and the induction of TH1 cells mediating the cellular autoimmune response are in positions DRB1-57 and 74 (an aspartic acid and a glutamic acid respectively, confer protection), modulated by D-57 in the DQ, 8 chain. These data show that DRB1-DQB1 haplotypes are central for IDDM expression and open new pathways for the disease management.