Exposure to non-persistent pesticides and puberty timing: a systematic review of the epidemiological evidence

BACKGROUND

Numerous modern non-persistent pesticides have demonstrated estrogenic/anti-androgenic activity and have been classified as endocrine-disrupting chemicals (EDCs). Processes involved in puberty development are vulnerable to EDCs, such as compounds that interfere with the metabolism or activity of sex steroids.

OBJECTIVE

To conduct a systematic review of epidemiological studies on the relationship between early-life exposure to non-persistent pesticides and puberty timing and/or sexual maturation in girls and boys.

METHODS

A systematic search was carried out using MEDLINE and SCOPUS databases, including original articles published up to November 2020.

RESULTS

Thirteen studies were selected after excluding non-original and non-human studies. Exposure to different types of pesticides has been associated with altered puberty timing in girls and/or boys in eight studies. In utero exposure to atrazine has been related to earlier age of menarche in girls; exposure to organophosphate (OP) pesticides has been related to delayed sexual development in boys and girls; childhood pyrethroid exposure has been associated with pubertal delay in girls and pubertal advancement in boys; and prenatal/childhood exposure to multiple pesticides has been linked to earlier puberty onset in girls and pubertal delay in boys.

CONCLUSIONS

Most of the reviewed studies describe a relationship between pesticide exposure and changes in the age of puberty onset or sex hormone levels, although the quality of the evidence is generally low. Further well-designed longitudinal studies are warranted on specific classes of pesticides and on possible interactions between different types of compounds.

Pubertal induction in adolescents with DMD is associated with high satisfaction, gonadotropin release and increased muscle contractile surface area

BACKGROUND

Pharmacological doses of glucocorticoids (GC) reduce inflammation and preserve muscle function in boys with Duchenne muscular dystrophy (DMD). Delayed puberty and bone fragility are consequences of GC treatment. The aim of this study was to determine the acceptability of a 2-year pubertal induction regimen using 4-weekly testosterone injections and examine changes in physique, bone integrity, muscle pathology (assessed by MRI) and muscle function.

METHODS

Fifteen prepubertal males with DMD, aged 12-17 years and receiving GC, were treated with an incremental testosterone regimen for 2 years. Participants completed a Treatment Satisfaction Questionnaire (TSQM). Data on BMI, bone density, muscle pathology and function were collected at baseline and 2 years later.

RESULTS

Testosterone injections were well tolerated, with high TSQM scores. Baseline BMI z-score was 2.16 (0.90) and 1.64 (1.35) 2 years later. Median testosterone levels were 9.7 nmol/L (IQR: 5.7-11.1) 6-9 months after the last injection with an associated increase in testicular volume. Lumbar spine z-score was 0.22 (s.d. 2.21) at baseline and 0.35 (s.d. 2.21) after 2 years. Upper and lower limb muscle contractile cross-sectional area increased in all participants during the trial (P = 0.05 and P < 0.01, respectively). There was a reduction in T2 relaxation times in most muscle groups with stable upper limb muscle function.

CONCLUSION

Incremental monthly testosterone injections were well tolerated, promoted endogenous testosterone production and had a positive impact on the skeleton and contractile muscle bulk with evidence suggesting a beneficial impact on the underlying disease process.

Association of phthalate exposure with precocious and delayed pubertal timing in girls and boys: a systematic review and meta-analysis

Exposure to phthalate derivatives has adverse effects on the health and development of humans, especially for children. A growing body of evidence supports the idea that exposure to phthalates can change an individual's physiological set point and the time of puberty in both genders. In this systematic review and meta-analysis, recent studies were evaluated to obtain systematic and regulation results in relation to puberty status and phthalate exposure in girls and boys. We searched English-language papers using Scopus, ISI, and PubMed databases as search engines, with no restriction of time, until the end of July 2019. A comprehensive literature search for an association between phthalate exposure and signs of puberty as well as levels of different types of hormones was carefully performed. Of the 67 studies retained for full-text screening, 39 studies were eligible for data management and extraction. For conducting a meta-analysis, four studies had appropriate effect size and metrics for pooling in the meta-analysis. Our findings revealed that low and high exposure to phthalates could alter pubertal development in both genders; the effects were either early or delayed puberty such as changes in the pubarche, thelarche, and menarche time, as well as in testicular volume. We statistically analyzed the association of pubic-hair development, breast development, and menarche time with exposure to phthalates in girls. For example, the pooled odds ratios of mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) in relation to breast development were (OR: 1.48, 95% CI: 1.11-1.85) and (OR: 1.52, 95% CI: 1.15-1.58) (P-value < 0.001), respectively. In addition, we analyzed the correlation between pubic-hair development and testicular volume with exposure to phthalates in boys. To the best of our knowledge, this is the first systematic review and meta-analysis of its kind for girls and boys. In conclusion, we found that a positive association exists between phthalate exposure and pubertal timing in the pediatric age group. Therefore, prevention of exposure to phthalates and reduction of their use should be underscored in the strategies for primordial prevention of pubertal timing and related consequences.

Chronic dietary changes in n-6/n-3 polyunsaturated fatty acid ratios cause developmental delay and reduce social interest in mice

Polyunsaturated fatty acids (PUFAs) are one of the main cellular building blocks, and dietary changes in PUFA composition are proposed as a potential route to influence brain development. For example, initial studies indicated that there is a relation between blood omega-6(n-6)/omega-3(n-3) PUFA ratios and neurodevelopmental disease diagnosis. To study the consequences of dietary n-6/n-3 PUFA ratio changes, we investigated the impact of a n-3 supplemented and n-3 deficient diet in developing BTBR T + Itpr3tf/J (BTBR) - a mouse inbred strain displaying Autism Spectrum Disorder (ASD)-like symptomatology - and control C57BL/6J mice. This study showed that pre- and postnatal changed dietary n-6/n-3 ratio intake has a major impact on blood and brain PUFA composition, and led to delayed physical development and puberty onset in both strains. The PUFA induced developmental delay did not impact adult cognitive performance, but resulted in reduced social interest, a main ASD behavioral feature. Thus, both chronic dietary n-3 PUFA supplementation and depletion may not be beneficial.

Guidelines for Gender Affirming Healthcare for Gender Diverse and Transgender Children, Young People and Adults in Aotearoa, New Zealand

Internationally and within Aotearoa, New Zealand, there has been a substantial increase in the demand for gender affirming healthcare over the past decade. It is likely that this level of referrals to health services will continue in the foreseeable future. The Guidelines for Gender Affirming Healthcare for Gender Diverse and Transgender Children, Young People and Adults in Aotearoa, New Zealand were developed following the recognition that the previous good practice guide required updating to be in step with current practice and international standards. This article presents a summary of the guideline focusing on puberty blockers, hormonal therapies, access to surgery and other gender affirming healthcare. We hope these guidelines will support the development and provision of services providing gender affirming healthcare around the country and provide helpful guidance to all health professionals involved in the care of trans people.

Psychological evaluation and medical treatment of transgender youth in an interdisciplinary "Gender Management Service" (GeMS) in a major pediatric center

In 2007, an interdisciplinary clinic for children and adolescents with disorders of sex development (DSD) or gender identity disorder (GID) opened in a major pediatric center. Psychometric evaluation and endocrine treatment via pubertal suppressive therapy and administration of cross-sex steroid hormones was offered to carefully selected patients according to effective protocols used in Holland. Hembree et al.'s (2009) Guidelines for Endocrine Treatment of Transsexual Persons published by the Endocrine Society endorsed these methods. A description of the clinic's protocol and general patient demographics are provided, along with treatment philosophy and goals.

Association between lead and cadmium and reproductive hormones in peripubertal U.S. girls

BACKGROUND

Lead (Pb) and cadmium (Cd) are known reproductive toxicants thought to disrupt hormone production throughout sensitive developmental windows, although this has not been previously examined in nationally representative peripubertal children.

OBJECTIVES

We examined the association between blood Pb and urinary Cd concentrations and the reproductive hormones inhibin B and luteinizing hormone (LH) in girls 6-11 years of age who participated in the cross-sectional Third National Health and Nutrition Examination Survey (NHANES III) (1988-1994).

METHODS

Pb (micrograms per deciliter) was measured in whole blood, and Cd was measured in urine (nanograms per milliliter). Inhibin B (picograms per milliliter) and LH (milli-International units per milliliter) were measured in residual sera for 705 girls. Survey logistic regression was used to estimate associations with pubertal onset based on inhibin B concentration > 35 pg/mL or LH concentration > 0.4 mIU/mL, and multinomial logistic regression was used to estimate the association between Pb and increasing categories of hormone concentrations.

RESULTS

High Pb (≥ 5 µg/dL) was inversely associated with inhibin B > 35 pg/mL [odds ratio (OR) = 0.26; 95% confidence interval (CI), 0.11-0.60; compared with Pb < 1 µg/dL]. At 10 and 11 years of age, girls with low Pb (< 1 µg/dL) had significantly higher inhibin B than did girls with moderate (1-4.99 µg/dL) or high Pb (≥ 5 µg/dL). In the subsample of 260 girls with levels of inhibin B above the level of detection and using survey regression modeling, inhibin B levels were lower among girls with both high Pb and high Cd (ß= -0.52; 95% CI, -0.09 to -1.04) than among girls with high Pb alone (ß= -0.35; 95% CI, -0.13 to -0.57), relative to girls with low Pb and low Cd.

CONCLUSIONS

Higher Pb was inversely associated with inhibin B, a marker of follicular development, and estimated effects suggestive of pubertal delays appeared to be stronger in the context of higher Cd concentrations. These data underscore the importance of Pb and Cd as reproductive toxicants for young girls.

IGF-1 administration to prepubertal female rats can overcome delayed puberty caused by maternal Pb exposure

Because prepubertal female rats maternally exposed to lead (Pb) exhibit suppressed serum levels of insulin-like growth factor-1 (IGF-1) and delayed puberty, we investigated the ability of centrally administered IGF-1 to stimulate luteinizing hormone (LH) release in vivo and LH-releasing hormone (LHRH) release in vitro from maternally Pb-exposed prepubertal female rats. Additionally, we assessed whether IGF-1 replacement could affect the timing of female puberty. Results demonstrated that IGF-1 stimulated significantly LH release in both control and Pb-exposed animals. When median eminences from control and Pb-exposed females were incubated with rat IGF-1 in vitro, they responded similarly with significant peptide-induced LHRH release. Lastly, we showed IGF-1 replacement reversed the delay in puberty caused by Pb. These results indicate the central LHRH response to IGF-1 is intact and that Pb-induced delayed puberty is due, at least in part, to suppressed circulating IGF-1 available to the hypothalamus.

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.

Maternal transfer of melatonin alters the growth and sexual maturation of young Indian palm squirrel Funambulus pennanti

To date, the phenomenon of maternal transfer of hormones to the young is an enigma. The present study explains for the first time the maternal transfer of melatonin (MEL) to the young, affecting neonatal growth and sexual maturation. The suckling pups of MEL-treated mothers exhibited significant decreases in body, testicular, vas deferens (male pups), ovarian and uterine (female pups) weights and increases in pineal gland activity along with high plasma MEL levels. The plasma level of testosterone decreased significantly in male pups, while estradiol increased and progesterone decreased in female pups of MEL-treated mothers. These results clearly suggest that MEL could be transported from the mothers to their young postnatally via the milk in order to influence neonatal growth and sexual maturation. Our results support the earlier concept and show for the first time that MEL can be transported from the mother to the young either prenatally through the placenta or postnatally via the milk. Therefore, maternal MEL can act as a biological signal for neonatal growth and sexual maturation.

Increased fetal glucocorticoid exposure delays puberty onset in postnatal life

The fetal environment is now recognized as a key determinant of the adult phenotype, being linked to development of diseases, including hypertension, as well as the timing of puberty. Such links may be related, in part, to the level of fetal exposure to maternal glucocorticoids in utero, which is normally regulated by placental expression of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD). The present study examined whether manipulation of fetal glucocorticoid exposure, either directly or indirectly via 11beta-HSD inhibition, influences the subsequent timing of puberty. Administration of dexamethasone acetate at low (LDEX, 0.25 microg/ml drinking water) or high doses (HDEX, 1 microg/ml) or carbenoxolone (CBX, 2 x 10 mg/day, sc; an inhibitor of 11beta-HSD) to pregnant rats from day 13 to term (day 23) reduced offspring birthweight (LDEX: 9%; HDEX: 27%; CBX: 8%) and resulted in a subsequent delay in the onset of puberty in females (control: 41.4 +/- 0.5; LDEX: 44.8 +/- 0.7; HDEX: 48.5 +/- 0.4; CBX: 43.6 +/- 0.5 days). Importantly, the effects of CBX were not observed in the absence of maternal adrenals, indicating that they were mediated by increased fetal exposure to endogenous maternal glucocorticoids. In contrast, maternal treatment with metyrapone (MET; an inhibitor of glucocorticoid synthesis; 500 microg/ml drinking water from day 13) increased birthweight by 5% and advanced puberty onset in male offspring (control: 48.8 +/- 1.0; MET: 45.7 +/- 0.8 days). Changes in the timing of puberty onset were not attributable to changes in either bodyweight at puberty or peripubertal plasma leptin concentrations. Peripubertal plasma LH was also unaffected in animals with delayed puberty but was elevated in male offspring of MET-treated mothers. Collectively, these results demonstrate that fetal glucocorticoid exposure is an important determinant of the timing of puberty onset in postnatal life, and that this effect is operable within the normal physiological range of glucocorticoid concentrations.

Effects of delaying puberty on bone mineralization in female rats

The effect of delaying puberty on bone mineralization was studied using female rats as a model. Repeated injections of gonadotrophin-releasing hormone antagonist (GnRHa) were used to suppress the onset of puberty from the age of 6-10 weeks. A group of control female rats was given aqueous solution injections at the same age and for the same duration. The effect of delaying puberty on bone mineralization was examined using dual energy X-ray absorptiometry (DXA) and peripheral quantitative computerized tomography (QCT), both methods being adapted for small animals. Bone mineral parameters were measured at baseline and at the ages of 10, 17 and 24 weeks in total body, femur and spine. Compared to controls, bone mineral content (BMC) and bone mineral density (BMD), as measured by DXA, were significantly decreased in GnRHa-treated rats in total body and femur at 10 and 24 weeks of age (P < 0.05). The results were even more significant after adjusting for weight. After this adjustment, spine BMC and BMD at 10, 17 and 24 weeks were significantly lower in the treatment group (P < 0.05). Trabecular BMD at the distal femur in the GnRHa treated group as measured by peripheral QCT was significantly lower (P < 0.05). However, cortical bone in the mid-femur had higher BMD, concurrent with lower cortical thickness in the treatment group. In conclusion, a delay in the onset of sexual maturation may cause prolonged, possibly irreversible defect in bone mineralization.

[Iatrogenic Cushing syndrome and mutatio tarda caused by dexamethasone containing nose drops]

Nasal steroid drops can produce iatrogenic Cushing's syndrome if the recommended dose is exceeded. We now report a 19-year-old male patient for whom dexamethasone nasal drops were prescribed because of nasal obstruction. He had been using these drops for more than 5 years, with a daily dexamethasone dose of 0.7-1.0 mg. It is likely that significant amounts of dexamethasone were swallowed and absorbed by the patient's gastrointestinal tract. As a consequence, the patient developed Cushing's syndrome with panhypopituitarism, growth retardation, osteoporosis and hypertension. A boyish size of the larynx resulted in a fundamental speaking frequency of a child. After discontinuing the intranasal use of the of dexamethasone and adjusting doses of hydrocortisone over 3.5 months a normalization of endocrine function occurred with the beginning of puberty and normal sexual changes. These findings show that the use of nasal steroid drops particularly in children should be limited to a short period and drugs with a low absorption dose employed.

Ovarian function after autologous bone marrow transplantation in childhood: high-dose busulfan is a major cause of ovarian failure

We studied pubertal status and ovarian function in 21 girls aged 11-21 years who had earlier received 1.2-13 years (median 7 years) high-dose chemotherapy and autologous BMT without TBI for malignant tumors. Ten of them were given busulfan (600 mg/m2) and melphalan (140 mg/m2) with or without cyclophosphamide (3.6 g/m2). Eleven others did not receive busulfan. Twelve girls (57%) had clinical and hormonal evidence of ovarian failure. Among nine others who had completed normal puberty, six had normal gonadotropin levels, one had elevated gonadotropin levels and two had gonadotropin levels at the upper limit of normal. The 10 girls who received busulfan all developed severe and persistent ovarian failure. High-dose busulfan is therefore a major cause of ovarian failure even when given in the prepubertal period. These findings emphasize the need for long-term endocrine follow-up of these patients in order to initiate estrogen replacement therapy.

Enzyme therapy for Gaucher disease: the first 5 years

Gaucher disease was first described by Philippe Gaucher in his 1882 medical thesis. Gaucher's original concept was of an unusual epithelioma of the spleen. By the early 1900s, Mandelbaum recognized the systemic nature of the disease. Several children with Gaucher disease were described at the turn of the century, but Rusca described a rapidly progressive fatal neurodegenerative type of disease, i.e. type 2, in the 1920s. The 'juvenile' form (type 3) of the disease was described in Sweden in the 1950s. In 1965, the deficient enzyme, acid beta-glucosidase, was discovered and the lysosomal nature of the disease was elucidated. Currently, three variants of Gaucher disease have been defined clinically and are distinguished by the presence and severity of neuronopathic involvement (Table 1). Each of these clinical types has substantial phenotypic variation, but types 1 and 3 have significantly heterogeneous rates of disease progression and degrees of visceral organs involvement. The neuronopathic involvement in type 3 also has substantial variation in the age of onset and disease progression even within relatively isolated communities. An extensive review of the clinical and pathologic involvement by Gaucher disease is available.

The impact of marrow transplant preparative regimens on subsequent growth and development. The Seattle Marrow Transplant Team

These data demonstrate that endocrine function abnormalities influencing subsequent growth and development in children after marrow transplantation rarely occur after preparation with CY alone. However, after administration of regimens containing TBI, multiple endocrine function abnormalities can occur. Although longer follow-up is needed, it appears that the addition of BU to CY does not result in thyroid function or growth abnormalities. Pubertal development and gonadal function, however, may be adversely influenced by BU and patients may require supplementation with appropriate gonadal hormones.

Growth and endocrine function in steroid sensitive nephrotic syndrome

Longitudinal height data and physical development were assessed in 29 boys and 12 girls taking long term steroid treatment for steroid sensitive nephrotic syndrome. Growth in both boys and girls, assessed by changes in height standard deviation score (delta Ht SDS), worsened significantly with chronological age. There was a significant negative correlation between delta Ht SDS and duration of treatment in boys, but not in girls. There was no correlation between delta Ht SDS and relapse rate or the use of cyclophosphamide. In the boys, Ht SDS decreased significantly only after the age of 10 years and was associated with delay in the appearance of secondary sexual characteristics. Eight adolescent boys were assessed endocrinologically by an overnight hormone profile. Blunting of the pulsatility of growth hormone and gonadotrophins was seen in six. Normal profiles were seen in two subjects who were both off steroid treatment at the time of study. Abnormal endocrine function in adolescent boys treated long term for steroid sensitive nephrotic syndrome corresponded with the clinical picture of delayed onset of puberty, which accounted for severe growth retardation in a substantial proportion of subjects.