Epidemic of breast enlargement in an Italian school

Pubertal gynecomastia incidence among 530,000 boys: a cross sectional population based study

Background

Adolescent gynecomastia, a benign proliferation of male breast tissue, can lead to psychological issues during adolescence. The prevalence varies widely (4%-69%). The incidence peaks are during neonatal, pubertal, and senescent periods. Its affect on emotional well-being necessitates understanding and occasional intervention. This study aimed to determine the incidence of gynecomastia among male adolescents aged 12-15 years.

Methods

A retrospective cross-sectional study utilized the Clalit Health Care Services database (2008-2021) with a population of approximately 4.5 million. Participants aged 12-15 years were included if diagnosed with gynecomastia (International classification of diseases-9 code 611.1) and having a body mass index (BMI) measurement and no obesity diagnosis (ICD9 code 278.0). Data analysis included incidence rates and associations with ethnicity, age, BMI, and socioeconomic status.

Results

531,686 participants included with an incidence of 1.08%. Of all participants, 478,140 had a BMI ≤ 25 with an incidence of 0.7%, and 0.25%-0.35% yearly, and 70% of gynecomastia patients were aged 13-14 years. The prevalence of gynecomastia differed between Jews (1.28%) and Arabs (0.67%), but the disparity diminished when socioeconomic status was considered.

Conclusions

This unprecedented Population study establishes a definitive rate of true pubertal gynecomastia, revealing a lower yearly incidence as compared to previous reports. The higher observed prevalence among Jewish adolescents, may be caused due to complex interactions between different influencing factors. Understanding these dynamics can aid in formulating more targeted interventions and policy strategies to address gynecomastia's affect on adolescent well-being.

Short-term serum and urinary changes in sex hormones of healthy pre-pubertal children after the consumption of commercially available whole milk powder: a randomized, two-level, controlled-intervention trial in China

Progesterone was found in commercial milk. After consuming this milk, compared with the control, serum progesterone levels after 3 h and urinary pregnanediol levels within 4 h increased, but those in urine after 48 h had no significant change.

Phytoestrogens (Resveratrol and Equol) for Estrogen-Deficient Skin-Controversies/Misinformation versus Anti-Aging In Vitro and Clinical Evidence via Nutraceutical-Cosmetics

The overarching theme for this review is perspective. Superfoods (a marketing term for fruits and vegetables, etc.) have a positive connotation, while many superfoods contain phytoestrogens, a term that is alarming to the public and has a negative connotation because phytoestrogens are endocrine-disruptors, even though they are strong antioxidants that have many health benefits. To understand phytoestrogens, this paper provides a brief summary of the characteristics of: (a) estrogens, (b) estrogen receptors (ER), (c) estrogen-deficient skin, (d) how perspective(s) get off track, (e) phytoestrogen food sources, and (f) misconceptions of phytoestrogens and food safety, in general, that influence person(s) away from what is true. Finally, a brief history of cosmetics to nutraceuticals is covered plus the characteristics of phytoestrogens, resveratrol and equol on: (g) estrogen receptor binding, (h) topical and oral dosing, and (i) in vitro, molecular mechanisms and select clinical evidence, where both phytoestrogens (resveratrol and equol) demonstrate promising applications to improve skin health is presented along with future directions of nutraceuticals. Perspective is paramount in understanding the controversies associated with superfoods, phytoestrogens, and endocrine-disruptors because they have both positive and negative connotations. Everyone is exposed to and consumes these molecules everyday regardless of age, gender, or geographic location around the world, and how we understand this is a matter of perspective.

The pharmacokinetics of letrozole and its effect on gonadotropins in anestrous ewes

The aim of this study was to determine the pharmacokinetics of letrozole and its effect on FSH and LH concentrations after single (IV, IM, SC) and repeated IV doses in anestrous ewes. This study was conducted in experiments 1 and 2 by randomly dividing 24 healthy Akkaraman ewes in anestrus into two equal groups. In experiment 1, the pharmacokinetics of letrozole following single IV, IM, and SC administration at 1 mg/kg dose and its effect of a single IV dose on plasma FSH and LH concentration were determined. In experiment 2, the effect of repeated IV doses of letrozole on FSH and LH concentrations was established. Plasma concentration of letrozole was measured using high-performance liquid chromatography, and pharmacokinetic parameters were calculated by non-compartmental analysis. FSH and LH concentrations were quantified using ELISA. The elimination half-life (t_1/2ʎz) for IV, IM, and SC routes were 9.94, 37.29, and 41.07 h, respectively. The IV route for letrozole had a total clearance of 0.11 L/h/kg and a volume of distribution at a steady state of 1.50 L/kg. The peak plasma concentration was 0.11 μg/mL for the IM route and 0.14 μg/mL for the SC routes. The bioavailability was 55.18% for the IM route and 75.34% for the SC route. Letrozole following single and repeated (every 24 h for 3 days) IV administrations at 1 mg/kg dose did not affect LH concentration in anestrous ewes but caused an increase in the FSH concentration. This increase in FSH concentration may create a potential for the use of letrozole in ovarian superstimulation protocols. Favorable pharmacokinetic properties (long t_1/2ʎz and good bioavailability) of letrozole for IM and SC routes require further investigation before use in estrus induction or estrus synchronization protocols in sheep.

The Fate of Synthetic and Endogenous Hormones Used in the US Beef and Dairy Industries and the Potential for Human Exposure

PURPOSE OF REVIEW

Growth-enhancing chemicals used by the beef and dairy industries may be bioavailable to humans via milk, meat, and other environmental matrices. This review evaluates the potential for environmental transport and bioavailability of the active chemical to humans.

RECENT FINDINGS

Bovine somatostatin is detectable in milk; however, there is no evidence that the protein persists in the environment nor that it is active in humans. In contrast, steroids are transported through milk and meat to humans where they may exert biological activity. Furthermore, environmental matrices such as raw water and dust may also allow for the environmental transport and bioavailability of steroids to humans. Endogenous and exogenous steroids can be found in the meat, milk, and waste materials produced by cattle. While the concentrations may be low, exposure to these matrices, most notably dairy products made with whole milk, can be a source of exogenous steroids to humans.

Premature Thelarche

Premature thelarche is a benign condition that affects young girls and may be interpreted as a sign of central precocious puberty (CPP). Parental concern is common when breast development is noted in a young girl. It is important to differentiate premature thelarche from CPP, as the latter is a more serious disorder that may affect final adult height and menarcheal age, and may have psychological implications as well. Distinguishing between the two conditions clinically may help the patients avoid unnecessary testing. Pediatricians can play a pivotal role by providing reassurance to families and helping alleviate parental anxiety. This article reviews the clinical presentation of premature thelarche, its usual course, and implications. [Pediatr Ann. 2018;47(1):e12-e15.].

Xenoestrogens Ethinyl Estradiol and Zearalenone Cause Precocious Puberty in Female Rats via Central Kisspeptin Signaling

Xenoestrogens from synthetic or natural origin represent an increasing risk of disrupted endocrine functions including the physiological activity of the hypothalamo-pituitary-gonad axis. Ethinyl estradiol (EE2) is a synthetic estrogen used in contraceptive pills, whereas zearalenone (ZEA) is a natural mycoestrogen found with increasing prevalence in various cereal crops. Both EE2 and ZEA are agonists of estrogen receptor-α and accelerate puberty. However, the neuroendocrine mechanisms that are responsible for this effect remain unknown. Immature female Wistar rats were treated with EE2 (10 μg/kg), ZEA (10 mg/kg), or vehicle for 10 days starting from postnatal day 18. As a marker of puberty, the vaginal opening was recorded and neuropeptide and related transcription factor mRNA levels were measured by quantitative real time PCR and in situ hybridization histochemistry. Both ZEA and EE2 accelerated the vaginal opening, increased the uterine weight and the number of antral follicles in the ovary, and resulted in the increased central expression of gnrh. These changes occurred in parallel with an earlier increase of kiss1 mRNA in the anteroventral and rostral periventricular hypothalamus and an increased kisspeptin (KP) fiber density and KP-GnRH appositions in the preoptic area. These changes are compatible with a mechanism in which xenoestrogens overstimulate the developmentally unprepared reproductive system, which results in an advanced vaginal opening and an enlargement of the uterus at the periphery. Within the hypothalamus, ZEA and EE2 directly activate anteroventral and periventricular KP neurons to stimulate GnRH mRNA. However, GnRH and gonadotropin release and ovulation are disrupted due to xenoestrogen-mediated inhibitory KP signaling in the arcuate nucleus.

Physiologically-based toxicokinetic modeling of zearalenone and its metabolites: application to the Jersey girl study

Zearalenone (ZEA), a fungal mycotoxin, and its metabolite zeranol (ZAL) are known estrogen agonists in mammals, and are found as contaminants in food. Zeranol, which is more potent than ZEA and comparable in potency to estradiol, is also added as a growth additive in beef in the US and Canada. This article presents the development and application of a Physiologically-Based Toxicokinetic (PBTK) model for ZEA and ZAL and their primary metabolites, zearalenol, zearalanone, and their conjugated glucuronides, for rats and for human subjects. The PBTK modeling study explicitly simulates critical metabolic pathways in the gastrointestinal and hepatic systems. Metabolic events such as dehydrogenation and glucuronidation of the chemicals, which have direct effects on the accumulation and elimination of the toxic compounds, have been quantified. The PBTK model considers urinary and fecal excretion and biliary recirculation and compares the predicted biomarkers of blood, urinary and fecal concentrations with published in vivo measurements in rats and human subjects. Additionally, the toxicokinetic model has been coupled with a novel probabilistic dietary exposure model and applied to the Jersey Girl Study (JGS), which involved measurement of mycoestrogens as urinary biomarkers, in a cohort of young girls in New Jersey, USA. A probabilistic exposure characterization for the study population has been conducted and the predicted urinary concentrations have been compared to measurements considering inter-individual physiological and dietary variability. The in vivo measurements from the JGS fall within the high and low predicted distributions of biomarker values corresponding to dietary exposure estimates calculated by the probabilistic modeling system. The work described here is the first of its kind to present a comprehensive framework developing estimates of potential exposures to mycotoxins and linking them with biologically relevant doses and biomarker measurements, including a systematic characterization of uncertainties in exposure and dose estimation for a vulnerable population.

Increased serum estrogenic bioactivity in girls with premature thelarche: a marker of environmental pollutant exposure?

The aim of the work was to investigate the pathophysiology of isolated premature thelarche (IPT) by determining the impact of pre/postnatal exposure to endocrine disrupting chemicals (EDCs) through evaluation of total serum estrogenic bioactivity (EBA). The pathophysiology remains elusive, although recent investigations suggested the role of EDCs in premature female breast development. We investigated 15 girls with IPT. Plasma estradiol, follicle-stimulating hormone, and luteinizing hormone were measured in basal state and after gonadotropin-releasing hormone testing; bone age and uterine length were also assessed for all patients. Total EBA of patient serum was analyzed with an ultrasensitive bioassay that we previously developed and compared with that of 18 age-matched control girls. Parents were interviewed about their environmental/occupational exposure to EDCs during the patient's prenatal/postnatal life. Nine families reported parental occupational/environmental EDCs exposure during prenatal/postnatal patient life; the mean total EBA found in these 9 IPT girls was significantly elevated (12.31 ± 6.64 pg/mL) in comparison with that of the 6 patients without exposure (2.53 ± 0.73 pg/mL) and the 18 age-matched controls (3.53 ± 2.23 pg/mL; p < 0.01). The significant increase in total EBA in these 9 girls with IPT suggests that premature female breast development may be related in some cases to higher pre/postnatal contamination by EDCs.

Endocrine disruptors and the breast: early life effects and later life disease

Breast cancer risk has both heritable and environment/lifestyle components. The heritable component is a small contribution (5-27 %), leaving the majority of risk to environment (e.g., applied chemicals, food residues, occupational hazards, pharmaceuticals, stress) and lifestyle (e.g., physical activity, cosmetics, water source, alcohol, smoking). However, these factors are not well-defined, primarily due to the enormous number of factors to be considered. In both humans and rodent models, environmental factors that act as endocrine disrupting compounds (EDCs) have been shown to disrupt normal mammary development and lead to adverse lifelong consequences, especially when exposures occur during early life. EDCs can act directly or indirectly on mammary tissue to increase sensitivity to chemical carcinogens or enhance development of hyperplasia, beaded ducts, or tumors. Protective effects have also been reported. The mechanisms for these changes are not well understood. Environmental agents may also act as carcinogens in adult rodent models, directly causing or promoting tumor development, typically in more than one organ. Many of the environmental agents that act as EDCs and are known to affect the breast are discussed. Understanding the mechanism(s) of action for these compounds will be critical to prevent their effects on the breast in the future.

ZEN and the art of breast health maintenance

Zearalenone (ZEN) is a non-steroidal mycoestrogen that widely contaminates agricultural products. ZEN and its derivatives share similar molecular mechanisms and activity with estrogens and interact with ERα and ERβ leading to changes in the reproductive system in both animals and humans. The reduced form of ZEN, α-ZEA ralenol, has been used as an anabolic agent for animals and also proposed as hormonal replacement therapy in postmenopausal women. Furthermore, both zearelanol ZEN and derivatives have been patented as oral contraceptives. ZEN has been widely used in the United States since 1969 to improve fattening rates in cattle by increasing growth rate and feed conversion efficiency. Evidence of human harm from this practice is provided by observations of central precocious puberty. As a result, this practice has been banned by the European Union. As ZEN has been associated with breast enlargement in humans, it has been included in many bust-enhancing dietary supplements but epidemiological evidence is lacking with regard to breast cancer risk. Extensive work with human breast cancer cell lines has shown estrogenic stimulation in those possessing ER but a reduction in DMBA-induced breast cancers in rodents given ZEN. Protein disulfide isomerase provides a molecular biomarker of dietary exposure to ZEN and its derivatives allowing the detection and control of harmful food intake. The interaction of ZEN with anti-estrogens, anticancer agents and antioxidants requires further investigation.

Urinary mycoestrogens, body size and breast development in New Jersey girls

BACKGROUND

Despite extensive research and interest in endocrine disruptors, there are essentially no epidemiologic studies of estrogenic mycotoxins, such as zeranol and zearalenone (ZEA). ZEA mycoestrogens are present in grains and other plant foods through fungal contamination, and in animal products (e.g., meat, eggs, dairy products) through deliberate introduction of zeranol into livestock to enhance meat production, or by indirect contamination of animals through consumption of contaminated feedstuff. Zeranol is banned for use in animal husbandry in the European Union and other countries, but is still widely used in the US. Surprisingly, little is known about the health effects of these mycoestrogens, including their impact on puberty in girls, a period highly sensitive to estrogenic stimulation.

OBJECTIVES AND METHODS

We conducted a cross-sectional analysis among 163 girls, aged 9 and 10 years, participating in the Jersey Girl Study to measure urinary mycoestrogens and their possible relationship to body size and development.

RESULTS

We found that mycoestrogens were detectable in urine in 78.5% of the girls, and that urinary levels were predominantly associated with beef and popcorn intake. Furthermore, girls with detectable urinary ZEA mycoestrogen levels tended to be shorter and less likely to have reached the onset of breast development.

CONCLUSIONS

Our findings suggest that ZEA mycoestrogens may exert anti-estrogenic effects similar to those reported for isoflavones. To our knowledge, this was the first evaluation of urinary mycoestrogens and their potential health effects in healthy girls. However, our findings need replication in larger studies with more heterogeneous populations, using a longitudinal approach.

Peripheral precocious puberty in a 4-month-old girl: role of pesticides?

A 4-month-old girl presented with sexual development, including breast enlargement, menstruation, uterine length of 69 mm at ultrasonography, and dramatically high estrogen bioactivity, but no growth acceleration, pubic hair, pelvis masses or adrenal tumors. Gas chromatography with an electron capture detector and mass spectrometry detected pesticides (p,p'-DDD, p,p'-DDT, lindane and endosulfan sulfate) in plasma from the infant, the mother, and the 38-year-old father, who reported a dramatic decrease in libido, and in soil samples from their farm. The precocious sexual development was probably caused by the estrogen activity of the environmental contamination by tons of pesticides stored in the family farm.

The relationship between pubertal gynecomastia, prostate specific antigen, free androgen index, SHBG and sex steroids

OBJECTIVE

To investigate the relationships between pubertal gynecomastia, prostate-specific antigen (PSA), free androgen index (FAI), sex hormone-binding globulin (SHBG) and sex steroids.

METHODS

A total of 61 male adolescents (10-17 years old; mean: 13.67 +/- 1.08) with gynecomastia were enrolled into the study group. A total of 65 healthy age-matched adolescents were included in the control group. Body mass index (BMI), Tanner staging, testis volume, stretched penis length (SPL) and bone age were evaluated. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), testosterone, free testosterone, SHBG, PSA levels were determined and FAI was calculated.

RESULTS

In the study group, free testosterone (p = 0.012) and FAI (p = 0.05) were significantly lower than the control group. In the control group, SHBG levels decreased (p < 0.05) and FAI increased (p < 0.05) significantly with increasing Tanner stages; however, no such difference was observed in the study group (p > 0.05). High FAI was found to decrease the risk of gynecomastia (odds ratio: 0.211, 95% confidence interval: 0.064-0.694, p = 0.01). PSA showed a positive correlation with FAI, free testosterone, Tanner staging, testosterone, E2 and LH levels.

CONCLUSIONS

PSA is a good indicator of androgen activity during puberty. However, owing to FAI remaining as the single significant variable for pubertal gynecomastia, we suggest that it is still the best parameter to elucidate the etiopathogenesis of gynecomastia as well as other pubertal developmental abnormalities in male adolescents, and further longitudinal studies are needed to investigate the relationships between PSA and FAI in puberty.

Estrogen exposure in a child from hair lotion used by her mother: clinical and hair analysis data

Premature estrogenic effects may result from exogenous exposure to estrogenic substances. We report the case of a 36-month-old girl who presented with vaginal bleeding, uterus enlargement, and thelarche. Questioning of the parents revealed that the child's mother had used hormone-based hair lotions on her own scalp and that the child was in the habit of playing with her mother's hair while falling asleep, and that the girl played with her mother's combs and the empty lotion vials. The onset of hyperestrogenic syndrome was temporally related to the handling of lotions containing ethynylestradiol 0.5%. Analysis of long scalp hairs from the girl and her mother identified ethynylestradiol in concentrations of 10.6 and 46.6 microg/g, respectively. Six months after the mother discontinued use of the estrogen-containing hair lotion, the girl's hyperestrogenic signs resolved. This case highlights the importance of obtaining histories of possible food and non-food environmental sources of contamination, the suitability of hair sampling to identify the origin of the contamination, and the opportunity to warn parents about hazards related not only to oral contraceptives, but also custom-compounded topical hormone preparations.

High growth rate of girls with precocious puberty exposed to estrogenic mycotoxins

OBJECTIVE

To test the hypothesis that human puberty timing can be advanced by environmental estrogen exposure.

STUDY DESIGN

We analyzed serum mycoestrogen contamination via high-performance liquid chromatography (HPLC) in 32 girls affected by central precocious puberty (CPP) and in 31 healthy female control subjects. All 32 patients received triptorelin (TR) for more than 12 months after diagnosis.

RESULTS

Increased serum levels of zearalenone (ZEA; 933.7 +/- 200.3 pg/mL; 95% CI, 723.5-1143.9) and of its congener alpha-zearalenol (106.5 +/- 1.9 pg/mL; 95% CI, 104.5-108.5) contaminated 6 girls with CPP, who were from a bounded Tuscany area. At diagnosis, ZEA levels correlated with patient height (r = 0.906, P < .05) and weight (r = 0.887, P < .05), but not with bone age. In patients who were mycotoxin-positive, height (F = 4.192; P < .01), weight (F = 3.915; P < .01), and height velocity (F = 2.777, P < .05) were higher than patients who were mycotoxin-negative during 12-months TR treatment. Height correlated with weight both in patients who were mycotoxin-positive (r = 0.986, P < .001) and in patients who were mycotoxin-negative (r = 0.994, P < .001). Body mass index, bone age, and gonadal secretion was not different in patient groups before and during TR treatment (P > .05).

CONCLUSIONS

Mycoestrogenic zearalenone is suspected to be a triggering factor for CPP development in girls. Because of its chemical resemblance to some anabolic agents used in animal breeding, ZEA may also represent a growth promoter in exposed patients.

Detrimental Psychological Outcomes Associated with Early Pubertal Timing in Adolescent Girls

Though often discussed as though it were a discrete event, puberty comprises one segment of a larger developmental continuum and is notable for rapid transformation across a multitude of domains. Research suggests that an earlier rate of pubertal maturation in girls correlates with a number of detrimental outcomes compared with on-time or later maturation. The present review synthesizes the research on negative psychological sequelae of early pubertal timing in adolescent girls. Emphasis is on three theoretical perspectives by which precocious development is believed to affect the emergence of adverse outcomes: biological, psychosocial, and selection effects.

Exposição ambiental a interferentes endócrinos com atividade estrogênica e sua associação com distúrbios puberais em crianças

A substância exógena que causa efeitos adversos na saúde de um organismo ou sua descendência, como resultado de distúrbios na função hormonal, é denominada interferente endócrino. Nos últimos anos, produtos ambientais com atividades hormonais têm sido documentados como causadores de anormalidades puberais ou reprodutivas em animais. Os poucos casos comprovados em humanos foram aqueles relacionados a exposições acidentais. Apesar disso, pediatras e pais recomendam a suspensão de todos os alimentos potencialmente contaminados, em especial carne (aves, gado) e derivados da soja quando a criança apresenta alguma alteração puberal. Estas recomendações, se não embasadas cientificamente, podem ter conseqüências deletérias, não apenas pela eliminação de fontes protéicas da dieta, como também por retardar a investigação de causas tratáveis. Por outro lado, a não investigação dos efeitos adversos destes produtos é da mesma forma danosa. Esta revisão descreve os principais interferentes endócrinos responsáveis por alterações puberais em humanos e conclui que, excetuando exposições acidentais a altas quantidades destes produtos, mais estudos são necessários para responsabilizar a ação crônica e em baixas doses destas substâncias na alteração do tempo de desenvolvimento puberal em nossa espécie.

Personal care products that contain estrogens or xenoestrogens may increase breast cancer risk

Established models of breast cancer risk, such as the Gail model, do not account for patterns of the disease in women under the age of 35, especially in African Americans. With the possible exceptions of ionizing radiation or inheriting a known genetic mutation, most of the known risk factors for breast cancer are related to cumulative lifetime exposure to estrogens. Increased risk of breast cancer has been associated with earlier onset of menses or later age at menopause, nulliparity or late first parity, use of hormonal contraceptives or hormone replacement therapy, shorter lactation history, exposure to light at night, obesity, and regular ingestion of alcohol, all of which increase circulating levels of unbound estradiol. Among African Americans at all ages, use of hormone-containing personal care products (PCPs) is more common than among whites, as is premature appearance of secondary sexual characteristics among infants and toddlers. We hypothesize that the use of estrogen and other hormone-containing PCPs in young African American women accounts, in part, for their increased risk of breast cancer prior to menopause, by subjecting breast buds to elevated estrogen exposure during critical windows of vulnerability in utero and in early life. These early life and continuing exposures to estrogenic and xenoestrogenic agents may also contribute to the increased lethality of breast cancer in young women in general and in African American women of all ages. Public disclosure by manufacturers of proprietary hormonally active ingredients is required for this research to move forward.

The sensitivity of the child to sex steroids: possible impact of exogenous estrogens

The current trends of increasing incidences of testis, breast and prostate cancers are poorly understood, although it is assumed that sex hormones play a role. Disrupted sex hormone action is also believed to be involved in the increased occurrence of genital abnormalities among newborn boys and precocious puberty in girls. In this article, recent literature on sex steroid levels and their physiological roles during childhood is reviewed. It is concluded that (i) circulating levels of estradiol in prepubertal children are lower than originally claimed; (ii) children are extremely sensitive to estradiol and may respond with increased growth and/or breast development even at serum levels below the current detection limits; (iii) no threshold has been established, below which no hormonal effects can be seen in children exposed to exogenous steroids or endocrine disruptors; (iv) changes in hormone levels during fetal and prepubertal development may have severe effects in adult life and (v) the daily production rates of sex steroids in children estimated by the Food and Drug Administration in 1999 and still used in risk assessments are highly overestimated and should be revised. Because no lower threshold for estrogenic action has been established, caution should be taken to avoid unnecessary exposure of fetuses and children to exogenous sex steroids and endocrine disruptors, even at very low levels.

Leptin levels in boys with pubertal gynecomastia

BACKGROUND

It has been reported that there is a relationship between circulating leptin and sex steroid hormones and leptin is able to stimulate estrogen secretion by increasing aromatase activity in adipose stromal cells and breast tissue. Leptin receptors have been also shown in mammary epithelial cells and it has been suggested that leptin is involved in the control of the proliferation of both normal and malignant breast cells.

AIM

To investigate circulating leptin levels in boys with pubertal gynecomastia.

METHODS

Twenty boys with pubertal gynecomastia who were in early puberty and had no obesity, and 20 healthy individuals matched for age, pubertal stage and body mass index (BMI) with the study group, were enrolled in the study. Body weight, height and left midarm circumference (MAC) and left arm triceps skinfold thickness (TSF) were measured and BMI was calculated. A fasting blood sample was collected and routine hormonal parameters including prolactin, beta-human chorionic gonadotropin (betaHCG), total and free testosterone, estradiol, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, androstenedione (AS) and dehydroepiandrosterone sulfate (DHEAS) levels were studied. Serum leptin levels were analyzed using radioimmunoassay.

RESULTS

The mean ages of the study and control group were not different (13.9 +/- 0.89 and 14.2 +/- 0.66, respectively). No significant difference was found for BMI, MAC and TSF values between the two groups. There was no significant difference for hormonal parameters including FSH, LH, total and free testosterone, estradiol, AS, DHEAS and estradiol/total testosterone ratio between boys with pubertal gynecomastia and the controls. Serum leptin levels were found significantly higher in the study group compared with the healthy controls (5.58 +/- 0.81 and 2.39 +/- 0.29 ng/ml, respectively; p <0.001). No correlation could be determined between serum leptin levels and hormonal parameters.

CONCLUSION

The presence of higher leptin levels in boys with pubertal gynecomastia indicates that leptin may be involved in the pathogenesis of pubertal gynecomastia. The role of circulating leptin in pubertal gynecomastia is probably related to increase in estrogen and/or estrogen/ androgen ratio by the stimulating effect of leptin on aromatase enzyme activity in both adipose and breast tissues, or a direct growth stimulating effect of leptin on mammary epithelial cells, or increase in sensitivity of breast epithelial cells to estrogen with inducing functional activation of estrogen receptors by leptin in breast tissue.

High incidence of central precocious puberty in a bounded geographic area of northwest Tuscany: an estrogen disrupter epidemic?

The potential health consequences of human exposure to environmental estrogen disrupters are not known. Because many chemical compounds are environmentally persistent, toxic and estrogen-active, they can dysregulate the hypothalamic-pituitary-gonadal axis, potentially inducing reproductive disorders such as central precocious puberty (CPP). We performed a multi-center analysis of CPP distribution in northwest Tuscany (NWT), an area of 5990 km2 with 1,280,895 inhabitants. Study criteria consisted of recorded CPP diagnoses and prescriptions of gonadotropin-releasing hormone analogs from January 1, 1998 to December 1, 2003. Although similar CPP prevalences were found in four major cities of NWT (Livorno, Lucca, Massa and Pisa) (mean 30.4 per 100,000 children, standard deviation 18.6; p > 0.05), Viareggio area (< 300 km2) with 19,219 child inhabitants (0-14 years of age) had the highest CPP prevalence: more than 161 CPP cases per 100,000 children. Living in Viareggio area significantly increased the risk of CPP (relative risk (RR) 5.73, 95% confidence interval (CI) 3.5-9.3; rate/risk difference 0.133%, p < 0.05). Annual CPP incidence in the Viareggio area was relatively constant and significantly higher than in other NWT areas (RR 5.04, 95% CI 2.3-11.2; rate/risk difference 0.03%, p < 0.05). Indeed, 47% of total NWT cases were distributed in the countryside (300?km2) surrounding Viareggio. Specifically, three villages - Camaiore, Pietrasanta and Stazzema - in Viareggio presented the highest CPP frequency: 216.1, 393.5 and 274.0 CPP cases per 100,000 children, respectively (RR 9.59, 95% CI 1.71-16.6; rate/risk difference 0.26%, p < 0.05). Owing to the definite geographic distribution of CPP and because increasing distance (km) from Pietrasanta rarefied CPP frequency, we suggest environmental factors (e.g. estrogen disrupter pollution) as major CPP determinants in NWT.

Prepubertal gynaecomastia: aetiology, course and outcome

BACKGROUND

Palpable and measurable glandular breast tissue is a rare finding in prepubertal boys and warrants thorough evaluation to rule out an underlying pathology.

OBJECTIVE

To characterize the course and outcome of prepubertal gynaecomastia, examine its effect on puberty, and try to identify its underlying cause.

PATIENTS AND METHODS

Twenty-nine out of 581 (5%) boys referred to our clinic for evaluation of gynaecomastia between 1980 and 2000 were prepubertal at diagnosis. Data on age at appearance of gynaecomastia, general and endocrine evaluation, course of growth and puberty, and treatment were collected from the medical files.

RESULTS

Prepubertal gynaecomastia was diagnosed at mean age of 8.9 +/- 2.2 years. In 27 of the 29 boys (93.2%) no underlying cause was identified. The remaining two boys (6.8%) had hyperaromatase syndrome. Nine boys (31%) were obese. Spontaneous resolution was recorded in six boys (20.5%), no change in 15 (52%), and further breast enlargement in eight (including the two with hyperaromatase syndrome) (27.5%). Accelerated growth and bone maturation rates were noted only in the two boys with hyperaromatase syndrome. Pubertal onset was documented in 13 boys at 11.8 +/- 1.1 years.

CONCLUSIONS

According to our large single tertiary care centre experience, 5% of boys referred for evaluation of gynaecomastia were prepubertal. The development of gynaecomastia was the only abnormality and was not associated with other pubertal signs or accelerated growth rate. In most cases, the gynaecomastia was idiopathic. Further prospective studies are needed to evaluate the pathophysiological mechanisms responsible for this phenomenon.

Technologies for the control of fat and lean deposition in livestock

When the ratio of lean to fat deposition is improved, so is feed conversion efficiency. Net benefits may include lower production costs, better product quality, less excretion of nitrogenous wastes into the environment, decreased grazing pressure on fragile landscapes, and reduced pressure on world feed supplies. However, finding a way to achieve these goals that is reliable, affordable, and acceptable to the majority of consumers has proved to be a major challenge. Since the European Union banned hormonal growth promoters (HGPs) 15 years ago, countries such as Australia and the United States have licensed new products for livestock production, including bovine growth hormone (GH), porcine and equine GH, and the beta-agonist ractopamine. There has also been considerable research into refining these products, as well as developing new technologies. Opportunities to improve beta-agonists include lessening their effects on meat toughness, reducing adverse effects on treated animals, and prolonging their duration of action. In the last regard, the combined use of a beta-agonist with GH, which upregulates beta-adrenoceptors, can produce an outstanding improvement in carcass composition and feed efficiency. Insulin-like growth factor-1 (IGF-1) mediates many of the actions of GH, but has proved to be of more use as a growth reporter/selection marker in pigs, than as a viable treatment. However, a niche for this product could exist in the manipulation of neonatal growth, causing a life-long change in lean:fat ratio. Another significant advance in endocrinology is the discovery of hormones secreted by muscle and fat cells, that regulate feed intake, energy metabolism, and body composition. Leptin, adiponectin and myostatin were discovered through the study of genetically obese, or double-muscled animals. Through genetic manipulation, there is potential to exploit these findings in a range of livestock species, although the production of transgenic animals is still hampered by the poor level of control over gene expression, and faces an uphill battle over consumer acceptance. There are several alternatives to HGPs and transgenics, that are more likely to gain world-wide acceptance. Genetic selection can be enhanced by using markers for polymorphic genes that control fat and lean, such as thyroglobulin, or the callipyge gene. Feed additives of natural origin, such as betaine, chromium and conjugated linoleic acid, can improve the fat:lean ratio under specific circumstances. Additionally, 'production vaccines' have been developed, which alter the neuro-endocrine system by causing an auto-immune response. Thus, antibodies have been used to neutralise growth-limiting factors, prolong the half-life of anabolic hormones, or activate hormone receptors directly. Unfortunately, none of these technologies is sufficiently well advanced yet to rival the use of exogenous HGPs in terms of efficacy and reliability. Therefore, further research is needed to find ways to control fat and lean deposition with due consideration of industry needs, animal welfare and consumer requirements.

Epidemic of Gynecomastia among Haitian Refugees: Exposure to an Environmental Antiandrogen

OBJECTIVE

To investigate an observed epidemic of gynecomastia among Haitian refugees in US detention centers in 1981 and 1982.

METHODS

All identifiable environmental exposures were investigated for estrogenic and antiandrogenic activity.

RESULTS

A high incidence of gynecomastia was observed among Haitian refugees in five detention centers in the United States. Of 284 men screened, 20 (from 18 to 53 years old) demonstrated new-onset gynecomastia (Tanner stages 2 to 5) in June 1982. The mean onset of gynecomastia was 130 +/- 12 days after arrival in the United States. Other symptoms included loss of libido (in all 20 patients) and decreased beard growth (in 10). Plasma concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, and estradiol were not significantly different from those in 20 age-matched control subjects. Environmental substances, including tap water and the delousing agents Kwell shampoo and R&C Spray (applied to bedding and clothing), were tested for estrogenicity and androgenicity. None of these substances bound to cytosol estrogen receptors. The delousing agents were assayed for androgen binding by using genital skin fibroblasts. R&C Spray competed equally with testosterone for androgen-binding sites. Phenothrin, the "multi-cide" component of R&C Spray, reproduced this competitive binding result. When tested for antiandrogenic effects on prostate growth by using immature male rats treated with testosterone-filled Silastic capsules, phenothrin antagonized androgen action, as demonstrated by decreased prostate weights.

CONCLUSION

The antiandrogenic activity of phenothrin may explain this unusual epidemic of gynecomastia.

Causes of gynaecomastia in young adult males and factors associated with idiopathic gynaecomastia

Gynaecomastia is a common clinical condition. Persistent pubertal or late onset idiopathic gynaecomastia is the leading cause of gynaecomastia in different series. The aim of this study was the assessment of the prevalence and characteristics of different causes of gynaecomastia in young adult males, and evaluation of the factors associated with idiopathic gynaecomastia. Fifty-three male patients (mean age 22.04 +/- 2.22, range 19-29), who had been admitted to our outpatient clinics with gynaecomastia as the main presenting symptom were enrolled in the study. Patients were evaluated with breast palpation, breast ultrasonography, anthropometric measurements and sex steroid levels. Secondary causes of gynaecomastia were ruled out. Thirty age-matched healthy individuals were also studied as healthy control group. Idiopathic gynaecomastia was diagnosed in 31 of 53 patients (58%), with 17 (32%) persistent pubertal and 14 (24%) late onset course. Other causes of gynaecomastia were hypogonadism in 13 cases (25%), hyperprolactinaemia in five (9%), chronic liver disease in two (4%), and drug induced (prolonged use of H2 antagonists) in two (4%). Patients with idiopathic gynaecomastia, either pubertal or late onset, were compared with the healthy control group in order to find out associated factors. Anthropometric measurements revealed a significant increase in body weight and body mass index (BMI) in the patient group compared with healthy controls (72.4 +/- 13.3 vs. 63.6 +/- 7.9 kg, p = 0.0086 and 25.2 +/- 4.0 vs. 21.5 +/- 2.7 kg/m2, p = 0.0001). Total skin fold thickness (SFT) of four different regions were also higher in the patient group (50.9 +/- 22.1 vs. 32.6 +/- 10.2 mm, p = 0.0006) indicating a higher body fat percentage. Total serum testosterone (4.76 +/- 1.31 vs. 5.70 +/- 1.06 microg/mL, p = 0.0038) and luteinizing hormone (LH) (4.80 +/- 1.92 vs. 7.32 +/- 1.90 mIU/mL, p < 0.0001) levels were significantly lower in the patient group while oestradiol levels were similar. There was a significant correlation between total testosterone and LH levels (r = 0.27, p = 0.0445). Total testosterone and LH levels were negatively correlated with BMI and total SFT. As a result most common form of gynaecomastia is idiopathic gynaecomastia either as persistent pubertal or late onset forms in young adult males. Idiopathic gynaecomastia is closely correlated with generalized obesity, reduced LH and testosterone levels which may be the result of increased conversion of testosterone to oestradiol in increased adipose tissue mass.

Effects of processing on zearalenone

Zearalenone (ZEN), a common contaminant of all major cereal grains worldwide, is produced by some plant pathogenic molds including Fusarium graminearum and F. culmorum. The biological activity of this mycotoxin is mainly attributed to its estrogenic activity that modulates/disrupts endocrine function in animals and possibly humans. Efforts have been made to reduce the level of ZEN by various chemical, physical, and biological processing methods. Some chemical treatments were shown to be effective in reducing zearalenone content in artificially or naturally contaminated foods. During physical processing, the fate of ZEN depended on its distribution in the food matrix and its chemical properties such as heat stability and solubility. For example, wet milling of contaminated corn resulted in starch that was essentially toxin-free. In contrast, animal feed fractions such as bran and germ, by-products of the wet milling process, tended to concentrate ZEN. Extrusion cooking, a complex process where food is subjected to heat, high pressures and shear stress, reduced ZEN levels in food as well as its estrogenic activity. Fermentation of foods with bacteria and yeast resulted in reduction in ZEN levels. However, fermentation can result in the conversion of ZEN to more potent derivatives such as cc-zearalenol. Further efforts are needed to identify effective methods for removing/detoxifying ZEN in foods.

Putative effects of endocrine disrupters on pubertal development in the human

Pubertal development is regulated by gonadotrophins and sex hormones. There has been a clear secular trend in the timing of puberty during the last century, puberty becoming earlier. Although improved nutrition is assumed to be the cause, this could partly be associated with exposure to so-called endocrine disrupters. Precocious puberty has been described in several case reports of accidental exposure to oestrogenic compounds in cosmetic products, food and pharmaceuticals. Local epidemics of premature thelarche have also been suggested to be linked to endocrine disrupters. Children adopted from developing countries to industrialized countries often develop precocious puberty. Not only precocious puberty, but also delayed puberty can, theoretically, be associated with exposure to endocrine disrupters. While it is very plausible that endocrine disrupters may disturb pubertal development, there is very little research on this and, therefore, we do not yet have any clear cause-effect relationships in humans.

Descriptive studies: what they can and cannot do

Descriptive studies often represent the first scientific toe in the water in new areas of inquiry. A fundamental element of descriptive reporting is a clear, specific, and measurable definition of the disease or condition in question. Like newspapers, good descriptive reporting answers the five basic W questions: who, what, why, when, where. and a sixth: so what? Case reports, case-series reports, cross-sectional studies, and surveillance studies deal with individuals, whereas ecological correlational studies examine populations. The case report is the least-publishable unit in medical literature. Case-series reports aggregate individual cases in one publication. Clustering of unusual cases in a short period often heralds a new epidemic, as happened with AIDS. Cross-sectional (prevalence) studies describe the health of populations. Surveillance can be thought of as watchfulness over a community; feedback to those who need to know is an integral component of surveillance. Ecological correlational studies look for associations between exposures and outcomes in populations-eg, per capita cigarette sales and rates of coronary artery disease-rather than in individuals. Three important uses of descriptive studies include trend analysis, health-care planning, and hypothesis generation. A frequent error in reports of descriptive studies is overstepping the data: studies without a comparison group allow no inferences to be drawn about associations, causal or otherwise. Hypotheses about causation from descriptive studies are often tested in rigorous analytical studies.

Multi-residue analysis of anabolics in calf urine using high-performance liquid chromatography with diode-array detection

We describe the development of an HPLC method with diode-array detection (DAD) for the analysis and identification of 20 substances with anabolic properties, that are considered as potential growth promoters, to be used for the analysis of extracts of calf urine samples. The substances are separated on an RP-Select B column using a mobile phase consisting of a mixture of acetonitrile and water. Gradient elution from 43-76% acetonitrile in water with a concave curve was used to achieve a good separation of the compounds with an acceptable analysis time. For the identification, a retention parameter and the UV spectrum were used. The retention parameter was the retention time corrected with a reference mixture. The latter reduced the standard deviations to about 25% of their original values. The limits of detection of the HPLC system ranged from 0.5-5 ng injected amount for the androgens, progestagens, stilbenes and resorcylic acid lactones and to 5-10 ng injected amount for the oestrogens. After extraction from urine the limits of detection were increased by the presence of matrix components, but they were between 5 and 10 ng injected amount for most of the substances.

Center for Veterinary Medicine's perspective on the beef hormone case

Steroidal sex hormones and synthetic derivatives are used in the US to enhance growth in food-producing animals. The European Economic Community has banned use of these same substances, reportedly on the grounds of food safety. The US maintains that this ban was and is a disguised restriction on trade. The technical grounds for bringing this case and the impact of the findings of the World Trade Organization on the regulation of animal drugs in the US is discussed.

Isoflavones, soy-based infant formulas, and relevance to endocrine function

For more than 60 years, soy-based infant formulas have been fed to millions of infants worldwide and studied in controlled clinical research. These products provide essential nutrients required for normal growth and development. The safety of isoflavones in soy-based products, including infant formulas, has been questioned recently owing to reports of possible endocrine effects in animals and in cultured cells. The literature offers no evidence of endocrine effects in humans from infant consumption of modern soy-based formulas. Growth is normal and no changes in the timing of puberty or in fertility rates have been reported in humans who consumed soy formulas as infants. Consequently, soy-based infant formulas continue to be a safe, nutritionally complete feeding option for most infants.

Incidence of gynaecomastia in 954 young males and its relationship to somatometric parameters

The incidence of gynaecomastia was evaluated in 954 healthy young men aged 18-26 years, and was correlated with several somatometric parameters (height, weight, testes size, eye colour, scalp hair colour, scalp hair density, acne, density and extent of body hair). Gynaecomastia (> 2 cm breast tissue) was found in 40.5% (bilateral 85%, left 7.8%, right 7.2%) of the subjects. Highly statistically significant differences were found between subjects with or without gynaecomastia in their weight (79.7 +/- 10.7 kg versus 69.1 +/- 7.8 kg respectively; p < 0.001) and in their body hair (subjects with gynaecomastia had more dense and extensive body hair than those without; p < 0.001). When the density and extent of body hair was analysed separately for each age, it was found that subjects with gynaecomastia had completed the development of body hair earlier, since 80% of them had completed their body hair by the age of 23 years versus only 45% of those without gynaecomastia. This observation leads to the assumption that obesity and/or an earlier maturation of the subjects with gynaecomastia may play a role in the development of breast tissue, although the possibility of an increased tissue sensitivity to hormonal action cannot be excluded.

Southwestern Internal Medical Conference: New developments in the diagnosis and treatment of sexual precocity

This article covers considerations in the etiology of various forms of precocious puberty and premature sexual development. The normal pubertal process with maturation of the hypothalamic pituitary gonadal axis is reviewed. The differential diagnosis of precocious puberty is discussed with particular emphasis on the difference between gonadotropin-dependent and gonadotropin-independent processes. Established therapies and newer medical treatments with their pathophysiologic rationale are considered in detail.

Adolescent gynecomastia. Differential diagnosis and management

Gynecomastia signifies a transient or permanent disturbance in steroid hormone physiology and occurs when the male breast is exposed to a decreased ratio of androgen to estrogen. This article discusses pubertal and pathologic gynecomastia, diagnostic approach, and treatment.

An epidemic of precocious development in Puerto Rican children

An alarming incidence of premature sexual development has been reported in Puerto Rico during the last 7 years. A significant increment of premature thelarche, premature pubarche, prepubertal breast enlargement in boys, and precocious pseudopuberty in girls has been observed throughout the island. Several food specimens analyzed by chromatography and cytosol receptor assay revealed significant levels of estradiol equivalent in some meat samples. We suspect that the early sexual development is caused by exogenous estrogen contamination in the food ingested by the children and by their mothers.