[Endocrine disrupters and male gonads].
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Child↗
Biomedical subjects
M P Guarneri
Publications and source records attributed to M P Guarneri.
Turner's syndrome.
Turner syndrome (TS) is the most common sex-chromosome abnormality in females. Short stature and hypogonadism are the classical clinical findings. The spontaneous final height (FH) ranges between 139 and 147 cm, representing a growth deficit of about 20 cm with respect to the unaffected population. GH therapy improves FH and should be started during childhood at a high dose of about 1 IU/kg/week (range 0.6-2 IU/kg/week). Some authors advocate combined therapy with an anabolic steroid at various doses (e.g. oxandrolone 0.05-0.1 mg/kg/day). This treatment results in a significantly increased FH, a large proportion of treated girls reaching a FH of more than 150 cm. Gonadal function is compromised during adolescence in about 80% of girls with TS, whilst in about 20% pubertal development occurs spontaneously. Oestrogen therapy should be started at the age of 13-14 years in hypogonadic patients; early onset of treatment (before 12 years) seems to compromise FH. Other concerns in these patients are fertility and osteopenia.
Adolescent↗
Etiology of central precocious puberty in males: the results of the Italian Study Group for Physiopathology of Puberty.
We reviewed the hospital records of 45 boys, followed in 13 pediatric departments throughout Italy, who had undergone computed tomography and/or magnetic resonance imaging for central precocious puberty (CPP). Twenty-seven patients (60%) had idiopathic CPP and 18 (40%) neurogenic CPP. A hamartoma of the tuber cinereum was found in six patients (33%). All patients with hypothalamic hamartoma had earlier onset of symptoms than patients with idiopathic CPP. Five patients (27%) were affected by type 1 neurofibromatosis, two had ependymoma and five patients had an intracranial anomaly. Basal LH and basal and peak LH/FSH ratio were greater, but not significantly, in boys with neurogenic CPP than in boys with idiopathic CPP. The highest LH peak levels were observed in patients with hamartoma; however, no correlation was observed between LH peak and the size of the hamartomas. In addition, bone age at diagnosis was more advanced in patients with hamartoma than in patients with other conditions. In conclusion, gonadotrophin-dependent precocious puberty may be of idiopathic origin or may occur in association with any CNS disorder. Further studies are needed in order to evaluate the effects of nutritional, environmental and psychosocial factors on the timing of sexual maturation, to explain the high incidence of idiopathic CPP in our male patients.
Brain Diseases↗
Factors influencing final/near-final height in 12 boys with central precocious puberty treated with gonadotrophin-releasing hormone agonists. Italian Study Group of Physiopathology of Puberty.
Gonadotrophin-releasing hormone agonists (GnRHa) have been demonstrated as the therapy of choice for central precocious puberty (CPP). Few studies have provided male patients' adult height data. In our multicenter study we evaluated long-term effects of different GnRHa preparations and final/near-final height (FH) in 12 boys with CPP and analyzed the factors influencing FH. Patients' mean chronological age at the time of diagnosis was 7.6 +/- 0.9 yr. Three patients were treated only with triptorelin at a mean dose of 90 microg/kg i.m. every 28 days. Nine patients initially received buserelin (at a mean initial dose of 53.4 microg/kg/day i.n. divided into 3-6 equal doses) or buserelin (at a mean dose of 36.7 microg/kg/day s.c.) and were subsequently switched to triptorelin. The GnRHa therapy was continued for 4.1 +/- 0.6 yr (range 2.9-5.4). The mean predicted adult height increased from 169.9 +/- 4.2 cm at diagnosis to 180.7 +/- 6.0 cm at the end of treatment. Mean FH was 176.1 +/- 6.1 cm (170.1-190.7), corresponding to mean SDS(CA) 0.4 +/- 0.8 (-0.6/2.5), mean SDSBA 0.2 +/- 0.9 (-0.6/2.4) and mean corrected SDS for target height of 0.4 +/- 0.6 (-0.8/1.2). Multiple regression analysis revealed that FH was mainly influenced by target height and height at discontinuation of GnRHa therapy. The present data indicate that GnRHa therapy significantly improves growth prognosis in boys with CPP and fully restores genetic height potential.
Body Height↗
Precocious puberty and body composition: effects of GnRH analog treatment.
INTRODUCTION: Body composition changes with age and sex differences become significant only after puberty. Boys and girls before the age of 8 yr do not differ in fat, lean or bone mineral mass. Hormonal influences during pubertal development determine the physiological adult male and female body composition phenotype. AIM: The aim of our study was to evaluate body composition changes due to central precocious puberty (PP) and the specific effects of therapy on these modifications. SUBJECTS AND METHODS: Sixteen patients (14 girls, 2 boys) were included in the study. They were diagnosed as affected by idiopathic PP according to standard hormonal and clinical criteria; anatomic alterations of hypothalamus-hypophysis region were excluded by MRI. Mean age at diagnosis was 5.9 +/- 1.9 yr. All patients received GnRH analog (Leuprolide or Triptorelin) treatment subcutaneously every 4 weeks for at least 1 yr. Mean period of treatment was 3.4 +/- 1.9 yr. Standard anthropometry and body composition analysis were performed at baseline and every 6-12 months. A group of healthy subjects with normal timing of puberty was matched (for age or for pubertal stage) served as the control group (CA or CP, respectively). RESULTS: Patients with PP showed at baseline a significant increase of BMI and relative body weight; lean and fat compartments were also increased but not significantly. During treatment, the PP group showed increased fat mass compared to CA (p<0.05), while no difference was found between PP and CP. Lean mass was similar to CA but lower than in CP (p<0.05). During treatment a significant increase in lean mass (both as total as well as limb mass) was observed. After stopping treatment there was no difference between PP and CP, except for lower lean mass (p<0.04). CONCLUSION: When puberty occurs precociously, lean and fat mass are not significantly different from age-matched control subjects. Data collected during treatment confirm a shortening of prepubertal lean mass development and the block of further lean mass development due to puberty itself, while fat mass accumulation continues. The net result of these modifications determines a typical body composition pattern in PP patients, after the end of therapy: lean mass is reduced by a shortening of the prepubertal growing period and by the "menopausal effect" of treatment itself. Fat mass is increased as a consequence of therapy and could lead to future obesity.
Adipose Tissue↗
Effect of estrogen replacement therapy on bone mineral content in girls with Turner syndrome.
Because a close relationship between estrogen deficiency and osteoporosis has been proven, it is possible that lifelong estrogen deficiency might be the cause of osteopenia in Turner syndrome. This study was done to characterize the effect of estrogen therapy on bone mineralization in girls with Turner syndrome. Radial bone mineral content values were found to be below the 95% normal confidence interval in 44 of 49 untreated patients, aged 10.82 +/- 3.45 years. An inverse correlation was found between the patients' ages and their delta bone mineral content values. The effect of beginning estrogen treatment early or late was studied in 16 girls who started the treatment before and 11 who started after age 12. Although they were still deficient compared with controls, the first group had better mineralization than the second (P = .0005). Finally, nine patients were followed prospectively during replacement therapy; their bone mineral content delta values changed significantly (P = .02) during the follow-up period (3.17 +/- 0.33 years), but the bone mineral content did not normalize. Our data show that estrogen deficiency per se does not cause osteoporosis in young girls with Turner syndrome. In fact, estrogen therapy prevented bone loss but failed to normalize the low bone mineral content values. Early treatment is preferable because it reduces the bone density deficit present in untreated patients.
Adolescent↗
[Changes in dynamic respiratory volumes in obese children and adolescents related to weight loss and sex].
Obesity is associated with various alterations in lung function in adults. These alterations appear to be proportional to the degree of EP and the beneficial effect of weight loss on respiratory function has been reported. Therefore, in 35 children and adolescents affected by essential obesity of medium-severe degree, we have evaluated the following parameters: FVC (forced vital capacity), PEF (peak expiratory flow), FEV1 (forced expiratory volume), FEV75, FEV50, FEV25, before and after six months of dieting. Twelve subjects (34%) showed at least a pathologic value of PEF and/or FEV50 before dieting. All the female patients normalized their parameters after six months of dieting, whilst 5 out of 7 males still showed pathologic respiratory indexes, although a similar weight loss was obtained in the two groups of patients. Our study enhances the presence of respiratory functions derangements in a significant percentage of children with medium-severe degree of obesity. A careful monitoring of these subjects is therefore necessary, in order to prevent further progression of the lung function damage. After dieting the pulmonary function improved in female patients only, suggesting that factors other than the EP are involved in the pathogenesis of the respiratory alterations.
Adolescent↗
Bone mass in young patients with type I diabetes.
We measured bone mineral content (BMC) with single photon absorptiometry in two groups of young patients with type I diabetes: the first group (prospective study) consists of 48 patients followed from onset to the third year of diabetes and the second group (cross-sectional study) consists of 66 long-term diabetics. Bone mineral content at onset of disease was lower than normal in only two cases. After 3 years of diabetes no male revealed BMC below the normal range but two females (6.6%) had low BMC values. In our cross-sectional study we found a BMC reduction in 12% of the cases. We did not find a relationship between bone deficit and duration of diabetes, or bone mass values and HbA1.
Adolescent↗
[Osteopenia in premature children: an emerging problem].
Osteopenia of preterm newborns is a condition of undermineralization which arises during the first years of life in very low birth-weight infants. The pathogenesis of disease is multifactorial, even if its main mechanism is the inadequate mineral intake (overall the inadequate phosphorus intake). A wide spectrum of signs and symptoms may be observed ranging from overt rickets to asymptomatic conditions. Diagnosis is usually based on either photon or biochemical findings (hypophosphoremia, hyper calciuria, hypophosphaturia). There is not agreement about the prevention and the treatment and about the benefit of any form of mineral supplementation. The aim of our study is a review of the recent studies concerning the osteopenia of prematurity to focus this new problem.
Bone Diseases, Metabolic↗
[Analysis of the nutritional behavior of the normal and diabetic population in childhood].
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Adolescent↗
Effect of insulin treatment on osteocalcin levels in diabetic children and adolescents.
To investigate bone mineral metabolism in insulin-dependent diabetes mellitus, serum osteocalcin, a marker of bone formation, was measured in 31 diabetic children at onset of disease and 15 days after metabolic improvement by insulin therapy. As a control group for osteocalcin levels we studied 31 healthy sex- and age-matched children. Mean values of serum osteocalcin at onset of diabetes were significantly lower than in control group (p < 0.001), but we did not find any difference after 15 days of insulin therapy. Osteocalcin and parathyroid hormone concentrations were significantly greater after 15 days of insulin treatment than at onset of disease (p < 0.001 and p < 0.01, respectively). The osteocalcin levels were negatively correlated both with fructosamine and with glycosylated hemoglobin (p < 0.01 and p < 0.001, respectively), and positively correlated with the degree of metabolic acidosis at onset (p < 0.05). Therefore we postulate that during glycometabolic imbalance there is a decrease in bone turnover that could be one of the etiological factors of diabetic osteopenia.
Child↗
[Endocrinological problems in male adolescents].
The male adolescent may present several endocrinological problems, the most frequent of which is the retardation or absence of puberty due to constitutional delay of growth and development. This form does not require therapy and must be distinguished from other forms of hypogonadism (primitive or secondary) by endocrine tests (LHRH test, nightly pulses LH secretion, plasmatic basal level of testosterone and after HCG, cerebral NMR). Hypogonadism treatment consists of replacement therapy with testosterone or testes stimulation with HCG or LHRH. Another frequent disease is gynecomastia, usually due to physiological enlargement of mammary gland during pubertal development, sometimes it may be secondary to hypogonadism, tumors, liver function abnormalities. Severe or psychologically disturbing gynecomastia can be corrected by reductive mammoplasty. Very often, adolescents may present diseases related to incorrect food habits. Obesity is common and anorexia is becoming an important problem also in males.
Adolescent↗
[Endocrinologic problems of the male adolescent].
The male adolescent may present several endocrinological problems, the most frequent of which is the retardation or absence of puberty due to constitutional delay of growth and development. This form does not require therapy and must be distinguished from other forms of hypogonadism (primitive or secondary) by endocrine tests (LHRH test, nightly pulses LH secretion, plasmatic basal level of testosterone and after HCG, cerebral NMR). Hypogonadism treatment consists of replacement therapy with testosterone or testes stimulation with HCG or LHRH. Another frequent disease is gynecomastia, usually due to physiological enlargement of mammary gland during pubertal development, sometimes it may be secondary to hypogonadism, tumors, liver function abnormalities. Severe or psychologically disturbing gynecomastia can be corrected by reductive mammoplasty. Very often, adolescents may present diseases related to incorrect food habits. Obesity is common and anorexia is becoming an important problem also in males.
Adolescent↗