Reference ranges for serum concentrations of lutropin (LH), follitropin (FSH), estradiol (E2), prolactin, progesterone, sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS), cortisol and ferritin in neonates, children and young adults

Pubertal maturation and programming of hypothalamic-pituitary-adrenal reactivity

Modifications in neuroendocrine function are a hallmark of pubertal development. These changes have many short- and long-term implications for the physiological and neurobehavioral function of an individual. The purpose of the present review is to discuss our current understanding of how pubertal development and stress interact to affect the hypothalamic-pituitary-adrenal (HPA) axis, the major neuroendocrine axis that controls the hormonal stress response. A growing body of literature indicates that puberty is marked by dramatic transitions in stress reactivity. Moreover, recent studies indicate that exposure to stressors during pubertal maturation may result in enduring changes in HPA responsiveness in adulthood. As puberty is marked by a substantial increase in many stress-related psychological and physiological disorders (e.g., depression, anxiety, drug abuse), it is essential to understand the factors that regulate and modulate HPA function during this crucial period of development.

Early life stress, the development of aggression and neuroendocrine and neurobiological correlates: what can we learn from animal models?

Early life stress (child and adolescent abuse, neglect and trauma) induces robust alterations in emotional and social functioning resulting in enhanced risk for the development of psychopathologies such as mood and aggressive disorders. Here, an overview is given on recent findings in primate and rodent models of early life stress, demonstrating that chronic deprivation of early maternal care as well as chronic deprivation of early physical interactions with peers are profound risk factors for the development of inappropriate aggressive behaviors. Alterations in the hypothalamic-pituitary-adrenocortical (HPA), vasopressin and serotonin systems and their relevance for the regulation of aggression are discussed. Data suggest that social deprivation-induced inappropriate forms of aggression are associated with high or low HPA axis (re)activity and a generally lower functioning of the serotonin system in adulthood. Moreover, genetic and epigenetic modifications in HPA and serotonin systems influence the outcome of early life stress and may even moderate adverse effects of early social deprivation on aggression. A more comprehensive study of aggression, neuroendocrine, neurobiological and (epi)genetic correlates of early life stress using animal models is necessary to provide a better understanding of the invasive aggressive deficits observed in humans exposed to child maltreatment.

Hydrocortisone treatment in girls with congenital adrenal hyperplasia inhibits serum dehydroepiandrosterone sulfate and affects the GH-IGF-I system

Sex hormones are modulators of the GH/ IGF-I system. We have hypothesized that the inhibition of DHEAS in treated girls with congenital adrenal hyperplasia (CAH) might affect this modulation. We analyzed serum IGF-I, IGFBP-3 and DHEAS in 17 prepubertal (Pp) and 32 pubertal (Pu) girls with CAH, under hydrocortisone replacement therapy, in the presence of normal (Gr1) or high (Gr2) serum testosterone (T) and androstenedione (A) levels. All groups had appropriate normal controls. Serum DHEAS in patients with CAH was significantly lower than in the respective controls (p < 0.04), except for Pp CAH Gr2. Serum IGF-I, but not serum IGFBP-3, in CAH subgroups was significantly higher than in the respective controls (p < 0.05), except for Pp CAH Gr2. It is concluded that glucocorticoid treatment of girls with CAH results in hypofunction of the adrenal zona reticularis. Low levels of serum DHEAS could be involved in the regulation of IGF-I biological response in target tissues. Additional studies are necessary to confirm these findings.

Stress response and the adolescent transition: performance versus peer rejection stressors

Little is known about normative variation in stress response over the adolescent transition. This study examined neuroendocrine and cardiovascular responses to performance and peer rejection stressors over the adolescent transition in a normative sample. Participants were 82 healthy children (ages 7-12 years, n = 39, 22 females) and adolescents (ages 13-17, n = 43, 20 females) recruited through community postings. Following a habituation session, participants completed a performance (public speaking, mental arithmetic, mirror tracing) or peer rejection (exclusion challenges) stress session. Salivary cortisol, salivary alpha amylase (sAA), systolic and diastolic blood pressure (SBP, DBP), and heart rate were measured throughout. Adolescents showed significantly greater cortisol, sAA, SBP, and DBP stress response relative to children. Developmental differences were most pronounced in the performance stress session for cortisol and DBP and in the peer rejection session for sAA and SBP. Heightened physiological stress responses in typical adolescents may facilitate adaptation to new challenges of adolescence and adulthood. In high-risk adolescents, this normative shift may tip the balance toward stress response dysregulation associated with depression and other psychopathology. Specificity of physiological response by stressor type highlights the importance of a multisystem approach to the psychobiology of stress and may also have implications for understanding trajectories to psychopathology.

Twenty-four hours secretion pattern of serum estradiol in healthy prepubertal and pubertal boys as determined by a validated ultra-sensitive extraction RIA

BACKGROUND

The role of estrogens in male physiology has become evident. However, clinically useful normative data for estradiol secretion in boys has not previously been established due to the insensitivity of current methods used in clinical routine. By use of a validated ultra-sensitive extraction RIA, our aim was to establish normative data from a group consisting of healthy boys in prepuberty and during pubertal development.

METHODS

Sixty-two 24-hours serum profiles (6 samples/24 hours) were obtained from 44 healthy boys (ages; 7.2-18.6 years) during their pubertal development, classified into five stages: prepuberty (testis, 1-2 mL), early (testis, 3-6 mL), mid (testis, 8-12 mL), late-1 (testis,15-25 mL, not reached final height) and late-2 (testis,15-25 mL, reached final height). Serum estradiol was determined by an ultra- sensitive extraction radioimmunoassay with detection limit 4 pmol/L and functional sensitivity 6 pmol/L.

RESULTS

Mean estradiol concentrations during 24-hours secretion increased from prepuberty (median: <4 (5-95 percentiles: <4 - 7) pmol/L) to early puberty (6 (<4 - 12 pmol/L) but then remained relatively constant until a marked increase between mid-puberty (8 (4 - 17) pmol/L) and late-1 (21 (12 - 37) pmol/L) puberty, followed by a slower increase until late-2 puberty (32 (20 - 47) pmol/L). The diurnal rhythm of serum estradiol was non-measurable in pre- and early puberty, but discerned in mid-puberty, and become evident in late pubertal stages with peak values at 0600 to 1000 h.

CONCLUSION

With the use of an ultra-sensitive extraction RIA, we have provided clinically useful normative data for estradiol secretion in boys.

Stress, aggression, and puberty: neuroendocrine correlates of the development of agonistic behavior in golden hamsters

During puberty, agonistic behaviors undergo significant transitions. In golden hamsters, puberty is marked by a transition from play fighting to adult aggression. During early puberty, male golden hamsters perform play-fighting attacks. This response type is gradually replaced by adult attacks over the course of puberty. Interestingly, this behavioral transition does not appear to be controlled by changes in gonadal steroids. Instead, the shift from play fighting to adult aggression in male golden hamsters is driven by pubertal changes in glucocorticoid levels. Specifically, the transition from play fighting to adult aggression coincides with developmental increases in glucocorticoid levels, and external manipulations such as social stress or treatment with corticosteroid receptor agonists accelerate this behavioral shift. Moreover, the consequences of social stress differ greatly between juvenile and adult male golden hamsters. Although a single defeat during adulthood causes severe and long lasting behavioral and neuroendocrine consequences, socially subjugated juveniles show only transient behavioral effects. As such, it is likely that pubertal changes in the HPA axis are not only linked to the maturation of offensive responses but also determine the consequences of social stress. Combined, these studies in golden hamsters provide a novel mechanism for the development of agonistic behavior and suggest that age related differences in behavioral plasticity are mediated by the development of the HPA axis.

Serum sex hormone-binding globulin levels in healthy children and girls with precocious puberty before and during gonadotropin-releasing hormone agonist treatment

CONTEXT

The regulation of SHBG is complex and influenced by sex steroids and insulin.

OBJECTIVE

Our objective was to describe serum levels and evaluate determinants of SHBG levels in healthy children and in girls with central precocious puberty (CPP) before and during GnRH analog (GnRHa) treatment.

DESIGN

We conducted a cross-sectional study on healthy subjects and a 2-yr longitudinal study in girls with CPP.

SETTING

The study took place at a tertiary referral center for pediatric endocrinology.

PARTICIPANTS/PATIENTS

A total of 903 healthy schoolchildren served as healthy subjects, and 25 girls with precocious/early puberty participated.

INTERVENTIONS

Girls with CPP were treated with the long-acting GnRHa triptorelin.

RESULTS

SHBG levels declined with increasing age in both sexes until adulthood. In healthy children, SHBG was significantly negatively correlated with testosterone, estradiol, dehydroepiandrosterone sulfate, and body mass index (BMI) in boys (total model R(2) = 0.71) but only with dehydroepiandrosterone sulfate and BMI in girls (total model R(2) = 0.26). Body fat percentage was significantly negatively correlated with SHBG levels (P < 0.001) in both boys (R(2) = 0.18) and girls (R(2) = 0.23). Girls with CPP had significantly lower pretreatment SHBG levels compared with age-matched controls [SHBG sd score, -1.29 (-4.48; 0.01)], which declined even further during GnRHa treatment [-2.75 (-5.9; 0.53); P < 0.001]. Even after adjustment for BMI and pubertal stage, girls with CPP had lower SHBG levels (P < 0.001) compared with healthy controls.

CONCLUSIONS

SHBG levels were strongly dependent on body composition and sex steroid levels in children with normal and precocious puberty. Studies on insulin sensitivity and SHBG in puberty are needed to better understand the interaction between body composition and gonadal maturation.

Salivary cortisol and DHEA levels in the Korean population: age-related differences, diurnal rhythm, and correlations with serum levels

PURPOSE

The primary objective of this study was to examine the changes of basal cortisol and DHEA levels present in saliva and serum with age, and to determine the correlation coefficients of steroid concentrations between saliva and serum. The secondary objective was to obtain a standard diurnal rhythm of salivary cortisol and DHEA in the Korean population.

MATERIALS AND METHODS

For the first objective, saliva and blood samples were collected between 10 and 11 AM from 359 volunteers ranging from 21 to 69 years old (167 men and 192 women). For the second objective, four saliva samples (post-awakening, 11 AM, 4 PM, and bedtime) were collected throughout a day from 78 volunteers (42 women and 36 men) ranging from 20 to 40 years old. Cortisol and DHEA levels were measured using a radioimmunoassay (RIA).

RESULTS

The morning cortisol and DHEA levels, and the age- related steroid decline patterns were similar in both genders. Serum cortisol levels significantly decreased around forty years of age (p < 0.001, when compared with people in their 20s), and linear regression analysis with age showed a significant declining pattern (slope=-2.29, t=-4.297, p < 0.001). However, salivary cortisol levels did not change significantly with age, but showed a tendency towards decline (slope=-0.0078, t=-0.389, p=0.697). The relative cortisol ratio of serum to saliva was 3.4-4.5% and the ratio increased with age (slope=0.051, t=3.61, p < 0.001). DHEA levels also declined with age in saliva (slope=-0.007, t=-3.76, p < 0.001) and serum (slope=-0.197 t=-4.88, p < 0.001). In particular, DHEA levels in saliva and serum did not start to significantly decrease until ages in the 40s, but then decreased significantly further at ages in the 50s (p < 0.001, when compared with the 40s age group) and 60s (p < 0.001, when compared with the 50 age group). The relative DHEA ratio of serum to saliva was similar throughout the ages examined (slop=0.0016, t=0.344, p=0.73). On the other hand, cortisol and DHEA levels in saliva reflected well those in serum (r=0.59 and 0.86, respectively, p < 0.001). The highest salivary cortisol levels appeared just after awakening (about two fold higher than the 11 AM level), decreased throughout the day, and reached the lowest levels at bedtime (p < 0.001, when compared with PM cortisol levels). The highest salivary DHEA levels also appeared after awakening (about 1.5 fold higher than the 11 AM level) and decreased by 11 AM (p < 0.001). DHEA levels did not decrease further until bedtime (p=0.11, when compared with PM DHEA levels).

CONCLUSION

This study showed that cortisol and DHEA levels change with age and that the negative slope of DHEA was steeper than that of cortisol in saliva and serum. As the cortisol and DHEA levels in saliva reflected those in serum, the measurement of steroid levels in saliva provide a useful and practical tool to evaluate adrenal functions, which are essential for clinical diagnosis.

Glucocorticoid therapy for hypotension in the cardiac intensive care unit

In recent years, it has been our practice to treat persistent hypotension in the cardiac intensive care unit with glucocorticoids. We undertook a retrospective review in an attempt to identify predictors of a hemodynamic response to steroids and of survival in these patients. Patients who had received glucocorticoids for hypotension over a 2-year period were identified retrospectively. Summary measures of blood pressure, heart rate, urine output, inotrope score, and volume of infused fluid were calculated for the 12 hours before and the 24 hours following initiation of glucocorticoid therapy. A hemodynamic response was defined as a > or =20% increase in mean blood pressure without an increase in inotrope score following initiation of steroid therapy. Fifty-one patients were included, of whom 6 (11.8%) died. Serum cortisol was measured in 43 patients (84.3%) and was below the lower limit of normal (<5 microg/dl) in 20 of these (46.5%). Following initiation of steroid therapy, blood pressure and urine output increased, whereas heart rate, inotrope score, and infused volume decreased. There were 21 (41.1%) hemodynamic responders, all of whom survived, whereas 6 of 30 (20%) nonresponders died (p = 0.036). No predictors of a hemodynamic response to steroid were identified. Some critically ill children with cardiac disease and inotrope refractory hypotension demonstrated hemodynamic improvement following glucocorticoid administration. An improvement in blood pressure following administration of glucocorticoid was associated with survival, but we were unable to identify predictors of that response.

The neurobiology of stress and development

Stress is a part of every life to varying degrees, but individuals differ in their stress vulnerability. Stress is usefully viewed from a biological perspective; accordingly, it involves activation of neurobiological systems that preserve viability through change or allostasis. Although they are necessary for survival, frequent neurobiological stress responses increase the risk of physical and mental health problems, perhaps particularly when experienced during periods of rapid brain development. Recently, advances in noninvasive measurement techniques have resulted in a burgeoning of human developmental stress research. Here we review the anatomy and physiology of stress responding, discuss the relevant animal literature, and briefly outline what is currently known about the psychobiology of stress in human development, the critical role of social regulation of stress neurobiology, and the importance of individual differences as a lens through which to approach questions about stress experiences during development and child outcomes.

Cortisol controls the pubertal development of agonistic behavior in male golden hamsters via type II corticosteroid receptors

In male golden hamsters, agonistic behavior undergoes a pubertal transition from play fighting to adult aggression. Previous studies have shown that this aspect of behavioral development is associated with pubertal increases in glucocorticoids and that daily social stress or injections of a synthetic glucocorticoid accelerate the transition. The goals of this study were to confirm the effects of cortisol on the development of agonistic behavior and to investigate the role of type II corticosteroid receptors in this process. First, animals treated with cortisol during early puberty [from postnatal days 31 (P-31) to P-36] showed an accelerated transition from play fighting to adult aggression. In a second experiment, the behavioral effects of cortisol were blocked by a co-treatment with a type II corticosteroid receptor antagonist. These findings are the first to show a facilitating role for type II corticosteroid receptors in the pubertal development of a social behavior. As such, these findings provide new insights into the neuroendocrine mechanisms controlling behavioral development during puberty.

Reference intervals for follicle-stimulating hormone, luteinizing hormone and prolactin in children and young adults on the bioMérieux Mini-Vidas system

We measured serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin concentrations on a bioMérieux Mini Vidas system in a pediatric population ranging in age from 1 to 19 years. Reference intervals were established separately for females and males, with stratification by age group and by Tanner's pubertal stage. FSH values were higher in females than in males, and were lowest in both sexes of age class 2 (4–8 years), increasing thereafter to the upper limit for stage PIV (females) and stage PV (males). LH values showed a similar pattern of change: concentrations were lowest for class 1 (1–3 years) and class 2 (4–8 years), and highest for stage PII (females) and stage PV (males). No significant difference was observed according to gender. Prolactin values did not differ markedly according to gender or pubertal status.

Clin Chem Lab Med 2007;45:541–5.

The relationship between red blood cell and reticulocyte indices and serum markers of iron status in the cord blood of newborns

BACKGROUND

The aims of this study were to assess the relationship between red blood cell and reticulocyte indices and biochemical iron status measurements, and to define reference values of these markers in the cord blood of newborns.

METHODS

In cord blood samples from 199 full-term newborns, cellular indices were assessed using an ADVIA 120 hematology system and iron status was analyzed by measurement of serum iron, transferrin, transferrin saturation (TfSat), transferrin receptor (TfR) and ferritin.

RESULTS

Cellular hemoglobin in red blood cells or reticulocytes was independent of serum iron markers such as TfSat, TfR and ferritin. The percentage of hypochromic red blood cells (%HYPOm) and reticulocytes (%HYPOr) correlated significantly with TfSat and TfR-F index (TfR/log ferritin). Importantly, %HYPOm and %HYPOr were also positively correlated with the high immature reticulocyte fraction (IRF-H) and the mean cell volume of red or reticulocytes.

CONCLUSIONS

In newborns, accelerated erythropoiesis is a major contributor to red blood cell and reticulocyte indices, which provide conflicting results when compared with serum markers of iron status. Apparently, the serum proteins ferritin, transferrin and TfR are more appropriate tools for the diagnosis of iron status in newborns.

Developmental and geographic variation in stress hormones in wild Belding's ground squirrels (Spermophilus beldingi)

Extensive research has been conducted on the role of glucocorticoids in regulating growth, mobilizing energy, responding to stressors and modulating learning and memory. However, little is known about the production of corticoids during early development in free-living animals, particularly during sensitive periods of acquisition of important behaviors. In a four-year study of Belding's ground squirrels, Spermophilus beldingi, a non-invasive assay of glucocorticoids was used to quantify age and population differences among juveniles from three California locations. Fecal-cortisol metabolites are elevated during a short period when juveniles first emerge aboveground from their natal burrows at about 4 weeks of age. This period of cortisol elevation coincides with when young are learning survival behaviors such as anti-predator responses and foraging strategies. Population differences in juvenile cortisol levels, which may reflect local variation in habitat quality and predator environments, were not evident until 2 weeks after emergence. Elevated cortisol at the age of emergence was also observed in juveniles born and reared in captivity without exposure to typical stressors that occur around the age of emergence. These results indicate that corticoids are regulated during early development, and the possible functions of age-related corticoid levels are discussed, including mobilization of glucose for natal emergence and later facilitation of growth and energy storage during the short summer before hibernation. In some species, elevated corticoids can also facilitate learning and memory, and current work is exploring whether the higher cortisol observed in all three S. beldingi populations just after emergence function to promote rapid acquisition of survival behaviors.

Estradiol levels and secretory dynamics in normal girls and boys as determined by an ultrasensitive bioassay: a 10 year experience

We utilized an ultrasensitive recombinant cell bioassay to measure serum estradiol in 800 normal children from birth through puberty. 105 children had repeat samples every 4 months as they approached puberty. We measured estradiol levels every hour for 24 hours in 55 children. Estradiol increased with age and pubertal stage in girls and boys, and was higher in girls than boys at each stage. Prepubertal girls have estradiol levels of 1.6 +/- 2.6 pg/ml. Prepubertal boys have estradiol levels of 0.4 + 1.1 pg/ml. Estradiol had a diurnal variation in girls and boys, with the trough occurring 08.00-20.00 h in girls, and 12.00-20.00 h in boys. We confirm that estradiol levels are higher in girls than boys even before physical signs of puberty, and that estradiol increases throughout puberty in girls and boys. This 10-year experience in 800 children shows the range and variability of estradiol by an ultrasensitive bioassay.

Steroid hormone levels in pregnancy and 1 year postpartum using isotope dilution tandem mass spectrometry

OBJECTIVE

To establish normal, trimester-specific reference intervals for serum 17beta-estradiol, progesterone (P), 17alpha-hydroxyprogesterone, cortisol, 11-deoxycortisol, androstenedione, DHEA, and DHEAS, measured simultaneously using isotope dilution tandem mass spectrometry.

DESIGN

Sequential cohort study.

PATIENT(S)

Healthy women undergoing a normal pregnancy (age, 25-38 years; mean, 30 years) attending a prenatal well clinic at gestation weeks 12, 22, and 32 and approximately 1 year postpartum.

MAIN OUTCOME MEASURE(S)

Trimester-specific reference intervals of endogenous steroid hormones analyzed using an isotope dilution tandem mass spectrometer equipped with an atmospheric pressure photoionization source with deuterium-labeled internal standards.

RESULT(S)

Serum estradiol, P, 17alpha-hydroxyprogesterone, and 11-deoxycortisol increased throughout pregnancy; cortisol increased up to the second trimester and then remained steady, while androstenedione increased by 80 percent by gestation week 12, then remained constant. Serum DHEA-S decreased by 50% by the third trimester.

CONCLUSION(S)

Trimester-specific reference intervals are reported for eight serum steroids. The ratios of individual serum hormone concentrations during pregnancy relative to their 1-year postpartum concentrations illustrate the expected normal trends of changes in hormone concentrations during pregnancy.

Glucocorticoids and the development of agonistic behaviour during puberty in male golden hamsters

During puberty, the agonistic behaviour of male golden hamsters undergoes a transition from play fighting to adult aggression. Repeated exposure to social stress early in puberty accelerates this transition. The present study investigated the possible role of glucocorticoids on the maturation of agonistic behaviour. First, we compared serum cortisol levels following a 20-min restraint stress during early puberty, mid-puberty or adulthood. Across puberty, animals exhibited a two-fold increase in post-restraint cortisol levels. We also compared corticotrophin-releasing hormone (CRH) immunoreactive fibres projecting to the median eminence between animals in early puberty and adulthood. The CRH fibre density was two-fold greater in adults compared to juveniles. Furthermore, we investigated the effects of stress hormones on the maturation of agonistic behaviour. Male hamsters were injected daily with dexamethasone, a corticosteroid receptor type II agonist (0, 10 or 40 microg/100 g), early in puberty from postnatal day 31 (P-31) to P-36. When paired with a smaller and younger intruder on P-37, attack frequency did not differ between groups. However, dexamethasone-treated animals showed a dose-dependent decrease in the percentage of play-fighting attacks and an increase in the percentage of adult attacks. In summary, puberty can be described as a period of increasing hypothalamic-pituitary-adrenal activity in male golden hamsters. Moreover, increasing glucocorticoid levels influence the maturation of agonistic behaviour. These data shed new light on the neuroendocrine mechanisms that regulate the maturation of social behaviours during puberty.

Coming of age: steroid hormones of wild immature baboons (Papio cynocephalus)

Large gaps exist in our knowledge about common patterns and variability in the endocrinology of immature nonhuman primates, and even normal hormonal profiles during that life stage are lacking for wild populations. In the present study we present steroid profiles for a wild population of baboons (Papio cynocephalus) from infancy through reproductive maturation, obtained by noninvasive fecal analyses. Fecal concentrations of glucocorticoid (fGC) and testosterone (fT) metabolites for males, and of fGC, estrogen (fE), and progestin (fP) metabolites for females were measured by radioimmunoassay (RIA). In males, infancy was characterized by high and declining levels of fGC and fT, whereas steroid concentrations were low during the juvenile years. During the months immediately prior to testicular enlargement, fT (but not fGC) concentration tended to increase. Males that matured early consistently had higher fT and fGC concentrations than those that matured late, but not significantly so at any age. Individual differences in fT concentrations were stable across ages, and average individual fT and fGC concentrations were positively correlated. For females, high and declining levels of fE characterized infancy, and values increased again after 3.5 years of age, as some females reached menarche by that age. Both fP and fGC were relatively low and constant throughout infancy and the juvenile period. During the months immediately prior to menarche, fGC concentration significantly decreased, while no changes were observed for fE levels. fP exhibited a complicated pattern of decrease that was subsequently followed by a more modest and nonsignificant increase as menarche approached. Early- (EM) and late-maturing (LM) females differed only in fP concentration; the higher fP concentrations in EM females reached significance at 4-4.5 years of age. Maternal rank at offspring conception did not predict concentrations of any hormone for either sex. Our results demonstrate the presence of individual endocrine variability, which could have important consequences for the timing of sexual maturation and subsequently for individual reproductive success. Further evaluation of the factors that affect hormone concentrations during the juvenile and adolescent periods should lead to a better understanding of mechanisms of life-history variability.

Effect of diet and red wine consumption on serum total antioxidant capacity (TAC), dehydroepiandrosterone-sulphate (DHEAS) and insulin-like growth factor-1 (IGF-1) in Italian centenarians

The traditional mediterranean diet is associated with a hope for longer survival. It has also been shown that the red wine possesses a protective effect against the oxidative stress. We studied TAC, the DHEAS and the IGF-1 in a group of 26 healthy centenarians, 17 women and 9 men, of the age range of 100--105 years. Furthermore, we analyzed also serum urate and bilirubin levels between drinkers and abstainers. Most of centenarian subjects have been moderate wine consumers (<500 ml/day of red wine). These subjects were subdivided as follows: (i) Group A: those who had maintained the style of their dietary habits as compared to the previous years (n=3 males, 10 females); (ii) Group B: those who actually consumed a diet being deficient compared to that of the previous years, but remained moderate drinkers of red wine (n=3 males, 4 females); and (iii) Group C: those who actually consumed a diet being deficient compared to that of the previous years, and at the same time, were abstainers in wine consumption (n=3 males, 3 females). The results show that in men three of the studied parameters decreased from Group A to C to considerable extents, as follows (mean+/-S.D.). TAC: 302.4+/-32.3; 142.0+/-24.1 and 96.4+/-20.1 micromol/l; DHEAS: 3.35+/-0.81; 2.52+/-0.18 and 1.34+/-0.14 micromol/l; IGF-1: 85.7+/-6.7; 76.6+/-6.7 and 65.6+/-2.6 ng/ml, respectively. For the same parameters, the results in the women were: TAC: 258.4+/-12.2; 182.1+/-14.0 and 107.6+/-10.0 micromol/l; DHEAS: 3.85+/-0.16; 2.34+/-0.19 and 2.05+/-0.04 micromol/l; IGF-1: 89.7+/-6.7; 76.6+/-4.7 and 64.2+/-2.7 ng/ml, respectively. We did not find any significant difference in the other serum parameters between drinkers (n=14) and abstainers (n=3) (urate: 267.6+/-52.9, and 289.5+/-80.1; bilirubin: 9.81+/-4.29 and 7.18+/-2.89 micromol/l, respectively). Our data suggest that the deteriorated diet caused a reduction of TAC, DHEAS and IGF-1 in the centenarians. However, red vine consumption exerted a protective effect against this trend, even if this protection is not reaching statistical significance in some cases (in men), which is due most probably to the lower number of male subjects in the study.

Pediatric reference intervals for FSH, LH, estradiol, T3, free T3, cortisol, and growth hormone on the DPC IMMULITE 1000

BACKGROUND

We studied serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), triiodothyronine (T3), free T3 (FT3), cortisol and growth hormone (GH) concentrations in a population of pediatric patients. The reference intervals were determined separately for females and males stratified by age groups to assess age- and sex-related differences. Our objective was to obtain reference intervals for the 7 serum analytes for our pediatric population using the IMMULITE 1000 system.

METHODS

Serum samples of 800 in- and out-patients, newborn to 19 years old were analyzed using the DPC IMMULITE 1000 chemiluminescent immunoassay system.

RESULTS AND CONCLUSIONS

We report pediatric reference intervals for FSH, LH, E2, T3, FT3, cortisol, and GH. These reference intervals provide the basis for clinical interpretation of laboratory results using the IMMULITE 1000 system and the assessment of child development.

Evaluation of a new automated electrochemiluminescent sex hormone-binding globulin (SHBG) immunoassay

Serum sex hormone-binding globulin (SHBG) regulates the cellular bioavailability of SHBG-bound steroid hormones. Since variations in SHBG levels may affect the concentration of free, i.e., biologically active testosterone in serum, SHBG levels are commonly measured as a supplement to total testosterone determination. The recently developed electrochemiluminescence Elecsys SHBG immunoassay was evaluated analytically on a Modular E170 (Roche Diagnostics, Mannheim, Germany) immunoanalyzer. Major differences in SHBG concentrations have been described among the commercially available methods; we therefore compared the new method with an established SHBG immunoradiometric assay (IRMA) in 99 routine serum samples. To provide reference values to clinicians, SHBG concentration was measured by Elecsys in 304 serum samples from healthy volunteers and several relevant clinical subgroups. The within-run and total imprecision coefficients of variation were </=2.9% and </=3.3%, respectively. Functional sensitivity was at least 0.74 nmol/L. Recoveries after dilution of high-concentration samples in low-titer human serum or in assay diluent were within the range of 85-110%. The Elecsys SHBG assay correlated well (r=0.98) with the SHBG immunoradiometric assay, but values were higher for the Elecsys assay (Passing Bablok regression analysis: slope 1.14, intercept +2.5). In healthy subjects and clinical subgroups, we confirmed the differences in SHBG values reported in the literature. The Elecsys SHBG immunoassay provides precision and reliability in combination with reduced turnaround time.

Clinical evidence that hyperinsulinaemia independent of gonadotropins stimulates ovarian growth

OBJECTIVE

Ovarian enlargement is a constant feature of syndromes of extreme insulin resistance. The objective of this study is to show the role of insulin on ovarian growth in the presence of low gonadotropin levels.

PATIENTS

Seven young patients with syndromes of extreme insulin resistance (five with lipodystrophy, one with Type B syndrome and one with Rabson-Mendenhall syndrome) were studied.

MEASUREMENTS

Baseline LH concentrations and luteinizing hormone releasing hormone (LHRH) tests were performed. Total testosterone, insulin and C-peptide values were measured. Pelvic ultrasounds were performed.

RESULTS

Four patients were prepubertal (age range 7-10 years old) and had prepubertal gonadotropin levels, and 2 of the 4 who were tested did not respond to LHRH (NIH 10 and RM-PAL). Three patients were Tanner stage 4 (age range 13-17 years old) and had low gonadotropins that did not respond to LHRH stimulation test. All seven patients had marked hyperinsulinaemia and 6 of 7 had at least one enlarged ovary. Testosterone values were increased in 4 of 7 patients.

CONCLUSION

This represents the first example of the pathologic role of insulin to stimulate ovarian growth with low circulating gonadotropins. Thus, while ovarian growth and steroidogenesis are normally stimulated by gonadotropins at puberty, hyperinsulinaemia stimulates pathologic growth of the ovary and an androgenic steroid profile that is active at all ages. We suggest that these patients constitute a model to separate the effect of insulin from gonadotropin in stimulating ovarian growth and/or steroidogenesis.

Estradiol levels in prepubertal boys and girls--analytical challenges

Increasing evidence points at an important function of low concentrations of estradiol (E2) in prepubertal boys and girls. E2 serum levels in prepubertal children are, however, often immeasurable in conventional E2 assays. This strongly hampers further investigation of the physiological relevance of E2 in children. In addition, there is an increasing concern of the potential effect of exposure to endocrine disrupters with estrogenic or antiandrogenic activity on pubertal development. A requirement of assessing the instance for this concern, adds further to the demands for applicable methodologies for the evaluation of the sensitivity of the organism to low E2 concentrations. Traditionally, E2 is measured by use of the radioimmunoassay (RIA). As an ultrasensitive alternative to the RIA, a recombinant cell bioassay has been developed. In this review, methodological aspects for these methods of analysis are examined and their applicability for evaluation of low E2 serum concentrations in children is estimated. Furthermore, available data on E2 levels in prepubertal boys and girls are evaluated and discussed, taking into consideration the limitations of the methods of analysis. In conclusion, there is a pronounced demand for new and improved methods of analysis for accurate and sensitive evaluation of low concentrations of E2.

Dysregulation of the Hypothalamic-Pituitary-Gonadal Axis with Menopause and Andropause Promotes Neurodegenerative Senescence

Senescence is characterized neurologically by a decline in cognitive function, which we propose is the result of degenerative processes initiated by the dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis with menopause and andropause. Compelling epidemiologic evidence to support this assertion includes the increased prevalence of Alzheimer disease (AD) in women, the correlation of serum HPG hormones with disease and the decreased incidence, and delay in the onset of AD following hormone replacement therapy. Dysregulation of the axis at this time leads to alterations in the concentrations of all serum HPG hormones (decreased neuronal sex steroid signaling, but increased neuronal gonadotropin releasing hormone, luteinizing hormone, and activin signaling). Hormones of the HPG axis, receptors for which are present in the adult brain, are important regulators of cell proliferation and differentiation during growth and development. Based on this, we propose that dysregulated HPG hormone signaling with menopause/andropause leads to the abortive reentry of differentiated neurons into the cell cycle via a process we term "dyosis." Interestingly, the major biochemical and neuropathologic changes reported for the AD brain also are intimately associated with neuron division: altered AbetaPP metabolism, Abeta deposition, tau phosphorylation, mitochondrial alterations, chromosomal replication, synapse loss, and death of differentiated neurons. Recent evidence supports the premise that AD-related biochemical changes are likely the combined result of increased mitotic signaling by gonadotropins and GnRH, decreased differentiative and neuroprotective signaling via sex steroids, and increased differentiative signaling via activins. This results in a hormonal milieu that is permissive of cell cycle reentry but does not allow completion of metaphase. Partial resetting of the axis following administration of normal endogenous sex steroids delays the onset and decreases the incidence of AD. Ideally, supplementation with HPG hormones should mimic closely the serum concentrations of all HPG hormones in reproductive men and cycling women to prevent dyotic signaling and attempted neuron division.

Timing of pubertal maturation in girls: an integrated life history approach

Life history theory provides a metatheoretical framework for the study of pubertal timing from an evolutionary-developmental perspective. The current article reviews 5 middle-level theories--energetics theory, stress-suppression theory, psychosocial acceleration theory, paternal investment theory, and child development theory--each of which applies the basic assumptions of life history theory to the question of environmental influences on timing of puberty in girls. These theories converge in their conceptualization of pubertal timing as responsive to ecological conditions but diverge in their conceptualization of (a) the nature, extent, and direction of environmental influences and (b) the effects of pubertal timing on other reproductive variables. Competing hypotheses derived from the 5 perspectives are evaluated. An extension of W. T. Boyce and B. J. Ellis's (in press) theory of stress reactivity is proposed to account for both inhibiting and accelerating effects of psychosocial stress on timing of pubertal development. This review highlights the multiplicity of (often unrecognized) perspectives guiding research, raises challenges to virtually all of these, and presents an alternative framework in an effort to move research forward in this arena of multidisciplinary inquiry.

Physical Growth and Endocrinal Disorders during Pubertal Maturation in Girls with Epilepsy

PURPOSE

This study investigated the effect of epilepsy and/or antiepileptic drugs (AEDs) on the physical growth, pubertal development, and androgenic status of girls with epilepsy between ages 8 and 18 years.

METHODS

Sixty-six female patients with epilepsy, their mean ages 13.47 +/- 3.5 years, were included. Anthropometric measurements, staging of pubertal maturation, and clinical manifestations of hyperandrogenism were assessed, as well as measurement of serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), and free androgen index (FAI). Of the included patients, 44 had transabdominal ultrasonic examination of the ovaries and fasting serum insulin levels were measured. Forty healthy age-matched females served as a control group.

RESULTS

Patients showed reduced mean height percentile compared with controls (z = 2.07; p = 0.04), which was negatively correlated with the duration of their epilepsy. Patients showed increased frequency of obesity, especially postpubertal girls taking valproate (VPA; 67%), who also showed higher insulin levels (t = 8.01; p = 0.0003). Patients showed increased frequency of clinical hyperandrogenemia in the different stages of puberty. High levels of testosterone and DHEAS were found in female patients with epilepsy, especially pubertal and postpubertal girls. Hyperandrogenism (clinical and/or laboratory) was most affected by the types of AEDs, with higher incidence in patients taking VPA compared with those taking enzyme-inducing AEDs (chi2= 9.16; p = 0.01). Eighteen percent of the patients were diagnosed as having polycystic ovary syndrome (PCOS). No difference was found in the types of seizures, degree of seizure control, type of AEDs, or insulin levels between patients with and those without PCOS.

CONCLUSIONS

Longer duration of the disease has a negative impact on the stature of female patients with epilepsy. Postpubertal girls taking VPA are more liable to obesity, which is associated with increased incidence of hyperinsulinemia. Clinical and/or laboratory evidence of hyperandrogenism is seen at a high frequency in patients, especially with the use of VPA. Furthermore, female patients with epilepsy especially in the postpubertal stage of sexual maturation, have a high prevalence of PCOS, independent of the type of AED or the characteristics of the epilepsy disorder.

The early dehydroepiandrosterone sulfate rise of adrenarche and the delay of pubarche indicate primary ovarian failure in Turner syndrome

Pubarche without thelarche has been taken as clinical evidence that adrenarche is independent of gonadarche in females. This study examines whether the course of adrenarche [rise of serum dehydroepiandrosterone sulfate (DHEAS)] and pubarche (Tanner stage PH2) is independent from ovarian function. Serum DHEAS levels (n = 867) were longitudinally measured in 111 girls with Turner syndrome between 1990 and 2002. Of these, 22 had spontaneous puberty onset (Tanner stage B2), and 45 had primary ovarian failure (POF). Serum DHEAS levels were assayed by chemiluminescence and compared with those of healthy girls (n = 322; age range, 3-17 yr in both groups). Between the ages of 7 and 17 yr, girls with Turner syndrome had significantly higher age-related DHEAS levels than normal girls (P </= 0.02). Moreover, in the 9- to 15-yr-old girls, DHEAS levels were significantly higher in girls with Turner syndrome and POF than in Turner syndrome girls with spontaneous puberty onset (P </= 0.02). This discrepancy was caused by an earlier adrenarche (DHEAS levels reaching 1.1 micro mol/liter) in Turner syndrome girls with POF, which occurred at a median age of 8.3 yr (80% confidence interval, 6.5-10.4 yr) vs. 10.5 yr (8.6-12.2) and 11.0 yr (8.9-12.6) in Turner syndrome girls with spontaneous puberty onset and normal girls, respectively (P = 0.003). In contrast, pubarche was delayed in Turner syndrome girls with POF [median age, 13.0 yr (80% confidence interval, 10.6-15.0) vs. 11.9 yr (10.5-13.2) in Turner syndrome girls with spontaneous puberty onset (P = 0.02) and 11.6 yr (10.6-12.5) in normal girls]. Primary gonadal failure in Turner syndrome is associated with an earlier onset of adrenarche, but delayed pubarche. These data demonstrate that normal timing of adrenarche is dependent on gonadal function and suggest that normal pubarche is the clinical manifestation of the ovarian conversion of DHEAS to active androgens.