Adrenarche and polycystic ovary syndrome: a tale of two hypotheses

Higher Prepubertal IGF-1 Concentrations Associate to Earlier Pubertal Tempo in Both Sexes

INTRODUCTION

Pubertal onset is triggered by multiple neuroendocrine interactions. The role of prepubertal IGF-1 in this process has not been explored in both sexes. Our objective was to analyze the association of prepubertal IGF-1 concentration with age at thelarche (B2) and menarche (M) in girls and age at gonadarche (G2) in boys.

METHODS

This is a longitudinal study (n = 1,196 boys and girls) within the Growth and Obesity Chilean Cohort Study (GOCS). At age ≈ 6.7 years, blood sample was taken for IGF-1. Subjects were divided into 4 groups according to the onset age of the pubertal event.

RESULTS

Higher prepubertal IGF-1 levels were observed at earlier ages of B2 (p = 0.003) and M onset (p = 0.041). A taller prepubertal height was observed at younger ages of B2 and M (p=<0.001 and 0.002, respectively). The hazard proportional regression models (HR) showed that with an increase of 1 SD in IGF-1, the HR of presenting B2 at younger ages was 1.25, and this association was maintained when adjusted for confounding variables. Similarly, the HR of presenting M at earlier ages was 1.21. This association was maintained only when adjusting for body mass index but not using further confounders. In boys, prepubertal IGF-1 showed a tendency to be significantly higher in children with earlier G2 and taller height (both p < 0.001). The HR of presenting G2 at younger ages was 1.22, and this association was maintained after adjusting for confounders.

CONCLUSIONS

Higher IGF-1 levels in mid-childhood are associated with earlier puberty onset. The role of IGF-1 in the onset of puberty requires further investigation.

Premature Adrenarche and its Association with Cardiovascular Risk in Females

Early activation of the adrenal zona reticularis, leading to adrenal androgen secretion, mainly dehydroepiandrosterone sulfate (DHEAS), is called premature adrenarche (PA). The fact that adrenal hyperandrogenism in females has been linked to a cluster of cardiovascular (CV) risk factors, even in prepubertal children, warrants investigation. Controversial results have been obtained in this field, probably due to genetic, constitutional, and environmental factors or differences in the characteristics of participants. In an attempt to understand, in depth, the impact of PA as a potential activator of CV risk, we critically present available data stratified according to pubertal status. It seems that prepubertally, CV risk is increased in these girls, but is somewhat attenuated during their second decade of life. Furthermore, different entities associated with PA, such as polycystic ovary syndrome, non-classical congenital adrenal hyperplasia, heterozygosity of CYP21A2 mutations, and the impact of DHEAS on CV risk, are reviewed. At present, firm and definitive conclusions cannot be drawn. However, it may be speculated that girls with a history of PA display a hyperandrogenic hormonal milieu that may lead to increased CV risk. Accordingly, appropriate long-term follow-up and early intervention employing a patient-oriented approach are recommended.

Hyperandrogenism during puberty in the development of polycystic ovary syndrome

The hormonal events of puberty, from adrenarche to menarche and beyond, include the secretion of androgens as well as estrogen and P. This normal pubertal process is briefly reviewed and a physiologic role for pubertal androgens proposed. It is further suggested that the hyperandrogenic state we call polycystic ovary syndrome is a maladaptation of the advantageous role of normal pubertal androgens.

Clinical characteristics of polycystic ovary syndrome in Indian women

BACKGROUND

Polycystic ovary syndrome (PCOS) is common diagnosis in women presenting with infertility. All the dimensions of PCOS have not been completely explored. Many studies have tried to characterize the exact presentation of the disease. In this study we studied clinical features of PCOS in Indian women to characterize different phenotypes of this syndrome. Prevalence of acanthosis nigricans (AN) as surrogate marker of insulin resistance, obesity, hirsutism and hypothyroidism in PCOS women have been simultaneously studied.

MATERIALS AND METHODS

Present work is a non comparative cross-sectional open label study carried out over a period of 18 months in an endocrinology hospital in western Maharashtra, India.

RESULTS AND CONCLUSION

Authors conclude that PCOS occurs both in obese and non-obese women; AN and hirsutism occur in equal proportion of patients. AN is correlated with obesity. Hormonal dysfunctions in PCOS manifested together or independently. PCOS women can be sub grouped based on clinical features suggestive of endocrinological malfunctions and can be investigated accordingly for selection of appropriate treatment modalities.

Adrenarche in nonhuman primates: the evidence for it and the need to redefine it

Adrenarche is most commonly defined as a prepubertal increase in circulating adrenal androgens, dehydroepiandrosterone (DHEA) and its sulfo-conjugate (DHEAS). This event is thought to have evolved in humans and some great apes but not in Old World monkeys, perhaps to promote brain development. Whether adrenarche represents a shared, derived developmental event in humans and our closest relatives, adrenal androgen secretion (and its regulation) is of considerable clinical interest. Specifically, adrenal androgens play a significant role in the pathophysiology of polycystic ovarian disease and breast and prostate cancers. Understanding the development of androgen secretion by the human adrenal cortex and identifying a suitable model for its study are therefore of central importance for clinical and evolutionary concerns. This review will examine the evidence for adrenarche in nonhuman primates (NHP) and suggest that a broader definition of this developmental event is needed, including morphological, biochemical, and endocrine criteria. Using such a definition, evidence from recent studies suggests that adrenarche evolved in Old World primates but spans a relatively brief period early in development compared with humans and some great apes. This emphasizes the need for frequent longitudinal sampling in evaluating developmental changes in adrenal androgen secretion as well as the tenuous nature of existing evidence of adrenarche in some species among the great apes. Central to an understanding of the regulation of adrenal androgen production in humans is the recognition of the complex nature of adrenarche and the need for more carefully conducted comparative studies and a broader definition in order to promote investigation among NHP in particular.

Higher levels of IGF-I and adrenal androgens at age 8 years are associated with earlier age at menarche in girls

CONTEXT

Earlier age at menarche is associated with rapid infancy weight gain and childhood obesity. The role of hormone levels in mediating these associations is unclear.

OBJECTIVE

The aim of this study was to identify childhood hormone levels at age 8 yr that are associated with early menarche, independent of body size.

DESIGN, SETTINGS, AND SUBJECTS

A total of 329 girls from a prospective United Kingdom birth cohort study provided blood samples at mean age 8.1 yr (range, 8.0-8.5) for hormone measurements and were followed longitudinally to establish age at menarche.

MAIN OUTCOME MEASURES

Fasting plasma levels of IGF-I, androstenedione, dehydroepiandrosterone sulfate (DHEAS), leptin, insulin, IGF binding protein-1, and SHBG were measured. Age at menarche was reported by questionnaire and categorized as before 12.0, 12.0-13.0, or later than 13 yr.

RESULTS

Earlier menarche was associated with greater body weight, height, and body mass index at age 8 yr (all P-trend <0.001). Before adjustment for body size, earlier menarche was associated with higher levels of IGF-I, androstenedione, DHEAS, leptin, and fasting insulin, and with lower levels of IGF binding protein-1 and SHBG at age 8 yr (all P < 0.01). After adjustment for body mass index and height at age 8 yr, only IGF-I (P = 0.004), androstenedione (P = 0.01), and DHEAS (P = 0.01) remained associated with earlier menarche.

CONCLUSIONS

Associations between higher levels of IGF-I and adrenal androgens at age 8 yr with earlier menarche, independent of body size, support functional roles of these hormones in regulating puberty timing in girls. Higher levels of these hormones reported in children who exhibited rapid weight gain during infancy may indicate their role in developmental pathways leading to earlier sexual maturation.

Adrenal androgen concentrations increase during infancy in male rhesus macaques (Macaca mulatta)

This study investigated adrenal androgens (AA), gonadotropins, and cortisol in castrated and gonad-intact male rhesus macaques from birth through infancy. Blood samples were collected longitudinally from castrated (n = 6; weekly, 1-40 wk) and intact (n = 4; every other week, 1-17 wk) males. Plasma concentrations of AA were determined by liquid chromatography-tandem mass spectrometry, and plasma concentrations of cortisol and gonadotropins were determined by RIA. Dehydroepiandrosterone sulfate (DHEAS) concentrations increased almost threefold (to 8 wk), dehydroepiandrosterone (DHEA) increased more than eightfold (to 11 wk), and androstenedione doubled (to 15 wk) in five castrated infant males and declined continuously thereafter. A sixth castrated male had markedly different temporal patterns and concentrations (many times more than 2 SDs from the cohort mean) of AA and gonadotropins from first sampling (3 wk) and was excluded from analysis. Cortisol increased over 16 wk but correlated poorly with DHEAS. Luteinizing and follicle-stimulating hormones increased to peaks at 3 and 7 wk, respectively. Testis-intact males exhibited similar profiles, but with earlier peaks of DHEAS (5 wk) and DHEA and androstenedione (7 wk). Peak concentrations of DHEAS were lower and those of DHEA and androstenedione were higher in intact than castrated infants. Testosterone was undetectable in castrated males and >0.5 ng/ml in intact males but was not correlated with DHEA or DHEAS. These are the first data documenting a transient increase in AA secretion during infancy in an Old World primate and are consistent with the previously documented time course of zona reticularis development that accompanies increases in androgen synthetic capacity of the adrenal. The rhesus is a promising model for androgen secretion from the human adrenal cortex.

Prepubertal adrenarchal androgens and animal protein intake independently and differentially influence pubertal timing

CONTEXT

Whether adrenarche impacts on pubertal development is controversial.

OBJECTIVE

The objective of the study was to examine the associations of adrenal androgen (AA) secretion with early and late pubertal markers, independent of potential influences of dietary animal protein intake.

DESIGN AND PARTICIPANTS

This was a prospective cohort study of healthy free-living Caucasian children (n = 109) who provided both 24-h urine samples and 3-d weighed dietary records 1 and 2 yr before the biological age at take-off of the pubertal growth spurt (ATO).

MEASUREMENTS

Twenty-four-hour excretion rates of androgen (C19) metabolites quantified by gas chromatography-mass spectrometry were measured.

MAIN OUTCOMES

ATO, age at peak height velocity (APHV), age at menarche/voice break, duration of pubertal growth acceleration, and ages at Tanner stage 2 for breast (girls) and genital (boys) development (B2-G2) and pubic hair (PH2).

RESULTS

Higher adrenarchal C19 steroids predicted earlier ages at Tanner stage 2 for pubic hair (P < 0.0001) and B2-G2 (P = 0.009) as well as a shorter pubertal growth acceleration period (P = 0.001), independently of animal protein intake. Children with a higher AA secretion had a 1.5-yr earlier beginning of pubarche and a 0.8-yr earlier beginning of B2-G2 than those with a lower AA excretion. Furthermore, animal protein intake was independently negatively associated with ATO and APHV (P < 0.05 each) and tended to be negatively associated with age at menarche/voice break (P = 0.07).

CONCLUSION

A higher animal protein intake may be involved in an earlier attainment of ATO and APHV, whereas a more intensive adrenarchal process may precipitate a shorter pubertal growth spurt and a notably earlier onset of breast and genital development in girls and boys, respectively.

Reproductive endocrinology: live birth prediction in polycystic ovary syndrome

Anovulatory infertility is common in polycystic ovary syndrome (PCOS). Clinicians who provide first-line treatment have to decide how best to induce ovulation with the desired outcome of live birth, a decision often complicated by the phenotypic heterogeneity of PCOS. could a new livebirth prediction model of different ovulation induction methods developed from basic clinical parameters help select infertility treatments?

Interventional studies for polycystic ovarian syndrome in children and adolescents

Polycystic ovarian syndrome (PCOS) is characterized by chronic anovulation, clinical and/or biochemical hyperandrogenism, which can be associated with altered insulin action. Symptoms usually begin around menarche, but onset after puberty may also occur as a result of environmental modifiers such as weight gain. The consequences of PCOS extend beyond the reproductive axis; there is a substantial risk for development of metabolic and cardiovascular abnormalities similar to the metabolic syndrome. Currently, the treatment is targeted to the patient's primary complaint such as hirsutism, restoration of regular menses or pregnancy. Pharmacological agents available for the treatment of hirsutism include androgen suppressors and peripheral androgen blockers. Recently, our understanding of the role of insulin resistance has led to the use of insulin-sensitizing medications as first-choice therapy. In conjunction with weight reduction and exercise, a pharmacologic reduction in insulin levels by either metformin or thiazolidinediones ameliorates both hyperinsulinemia and hyperandrogenism.

Polycystic ovary syndrome in the adolescent

Polycystic ovary syndrome (PCOS) is now recognized as a heterogeneous disorder that results in overproduction of androgens, primarily from the ovary, leading to anovulation and hirsutism and is associated with insulin resistance. Long-term sequellae of PCOS include higher risk for diabetes, obesity, metabolic syndrome, endometrial hyperplasia, and anovulatory infertility. Symptoms in the adolescent include oligomenorrhea, hirsutism, acne, and weight gain. Insulin resistance, impaired glucose tolerance, and diabetes have also been demonstrated in adolescents who have PCOS. Treatment should be instituted early to decrease symptoms and long term sequellae of PCOS. Weight loss, oral contraceptives, and antiandrogens are effective in treating the symptoms of this disorder. Insulin-sensitizing medications have been shown to be effective but should be used with caution until larger randomized trials have shown short- and long term benefits and efficacy over traditional therapies in the adolescent population.

Adrenal function during childhood and puberty in daughters of women with polycystic ovary syndrome

CONTEXT

In some patients, PCOS may develop as a consequence of an exaggerated adrenarche during pubertal development.

OBJECTIVE

The aim of the study was to assess adrenal function during childhood and pubertal development in daughters of women with PCOS (PCOSd).

DESIGN

We included 98 PCOSd [64 during childhood (ages 4-8 yr) and 34 during the peripubertal period (ages 9-13 yr)] and 51 daughters of control women (Cd) [30 during childhood and 21 during the peripubertal period]. In both groups, an acute ACTH-(1-24) stimulation test (0.25 mg) and an oral glucose tolerance test were performed. Bone age and serum concentrations of cortisol, androstenedione, 17-hydroxyprogesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), glucose, and insulin were determined.

RESULTS

PCOSd and Cd were similar in age and body mass index. During the peripubertal period, basal and poststimulated DHEAS concentrations were higher in PCOSd compared to Cd. Among PCOSd, 12.5% of girls in childhood and 32.4% in peripuberty presented biochemical evidence of exaggerated adrenarche. Stimulated insulin was higher in PCOSd compared to Cd during childhood (P = 0.03) and peripuberty (P = 0.03). An advancement of 8 months between bone and chronological age was observed in peripubertal PCOSd compared to Cd.

CONCLUSIONS

In PCOSd, basal and stimulated DHEAS concentrations were higher during the onset of puberty. Around 30% of the PCOSd demonstrated an exacerbated adrenarche, which may reflect increased P450c17 activity. In addition, a modest advance in bone age was observed, probably secondary to the hyperinsulinemia and/or adrenal hyperandrogenism.

Treatment for polycystic ovary syndrome: a critical appraisal of treatment options

The management of polycystic ovary syndrome (PCOS) usually spans a woman's reproductive years. While the treatment of symptoms is a primary concern, given its long-term nature, the benefits and potential risks need to be assessed and balanced. The variability of presentation coupled with the phenotypic diversity of this patient population, requires the individualization of treatment to each patient. Periodically, the regimen has to be modified owing to a desire for pregnancy, necessitating ovulation induction in this anovulatory group of women. Finally, for any treatment offered, consideration should be given to potential adverse effects on the fetus should spontaneous ovulation and unplanned pregnancy occur. This review highlights the current issues surrounding PCOS and provides a critical appraisal of treatment options.