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Luteinizing hormone and follicle stimulating hormone secretion patterns in boys throughout puberty measured using highly sensitive immunoradiometric assays.

Pulsatile gonadotrophin secretion patterns were studied in 32 normal boys (chronological age, CA 7.2-14.6 years) at different stages of pubertal development (5 in stage G1, 11 in G2, 5 in G3, 4 in G4, 7 in G5). Plasma LH and FSH concentrations were measured at 10 min intervals from 1200 to 1800 h and from 2400 to 0600 h using an immunoradiometric assay with a lower limit of detection of 0.15 IU/l for both LH and FSH. Plasma testosterone (T) was measured hourly. In the young prepubertal boys plasma LH was not detectable during day or night. In contrast, plasma FSH ranged from 0.7 to 1.4 IU/l. Plasma T was not detectable either (less than 0.25 nmol/l). In the older prepubertal boys a discrete pulsatile LH pattern (2 per 6 h) became discernible only during the night (range 0.1-0.4 IU/l). Plasma FSH also revealed a pulsatile pattern only during the night (2 per 6 h), while plasma T still remained undetectable. In the early pubertal boys (G2) a median daytime LH value of 0.37 IU/l was determined with 1 pulse per 6 h and at night definite LH pulses (4 per 6 h) were found in all boys (range 0.4-4.7 IU/l). Plasma FSH increased considerably to a median level of 2.50 IU/l during the day; most boys had a pulsatile FSH pattern (one per 6 h). Plasma T became detectable during the day (median 0.54 nmol/l) and night (median 1.16 nmol/l). With the progression of puberty the mean plasma level of LH and FSH, the LH/FSH pulse number and the LH/FSH pulse amplitude increased; plasma T rose as well, more obviously during the night. In G5, however, the LH pulse number decreased, while the LH level and pulse amplitude still increased, presumably as a result of the increased negative feedback action of sex steroids. Simultaneous LH/FSH pulses developed during the night at onset of puberty but during the day only towards the end of pubertal development. The use of these novel highly sensitive IRMA methods demonstrated nocturnal LH and both diurnal and nocturnal FSH pulsatility to be present in older prepubertal boys. The early detectable FSH level plus the existence of solitary FSH pulses throughout puberty as well as in adult men support the hypothesis of the existence of a GnRH-independent FSH secretion in men. Our results are in accordance with the following hypotheses: (1) puberty is brought about by GnRH secretion increasing with time, both in frequency and amplitude, and first appearing during the night.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Luteinizing hormone and follicle stimulating hormone secretion patterns in girls throughout puberty measured using highly sensitive immunoradiometric assays.

Pulsatile gonadotrophin secretion patterns were studied in 36 healthy girls by measuring every 10 min and applying immunoradiometric assays (IRMA). Different stages of puberty were associated with significant changes in the plasma LH and FSH levels, pulse numbers (Pno) and pulse amplitudes (pA). Plasma LH was not detectable by day or night in young prepubertal girls (B1), neither was plasma oestradiol (E2); however, plasma FSH was detectable in a pulsatile pattern. In the older prepubertal girls (B1-onset) a discrete pulsatile LH pattern became detectable only during the night; plasma FSH tended to rise, while E2 became just detectable. In the early pubertal girls (B2) most daytime LH values were above the detection limit, in some with low-amplitude pulses. At night, pulses with a wide range of pulse amplitudes were detected. Plasma FSH increased further, plasma E2 only slightly. With the progression of puberty the plasma LH and FSH levels, Pno and pA increased significantly from stage B2 to B3 during the day (P less than or equal to 0.05) and close to significance during the night (0.05 less than or equal to P less than or equal to 0.1). However, in stage B4 the secretory characteristics tended to decline, while from stage B3 onwards plasma E2 started to rise rapidly (P less than or equal to 0.05, during the night from stage B2 to B3, during the day from B3 to B4m-). Simultaneous LH and FSH pulses were observed throughout puberty, usually during the night. Using these IRMA methods nocturnal LH in older prepubertal girls and both diurnal and nocturnal FSH pulsatility could be demonstrated in young prepubertal girls. From this study we conclude that (1) puberty in girls, as in boys, may be brought about by an increasing GnRH secretion both in frequency and amplitude, first appearing during the night. This increased GnRH stimulation results in LH secretion only during the night; (2) a cyclical pulsatile LH pattern including an LH surge can be established before the menarche; the capacity for positive feedback activity is not the final maturation characteristic to achieve an ovulatory menstrual cycle.

Adolescent↗

Biliary cholesterol saturation in non-obese women and non-obese men before and after puberty.

The lipid composition of gallbladder bile was determined in forty-seven normal, non-obese subjects (twenty females and twenty-seven males) without gallstones ranging in age from seven months to twenty-nine years. Before puberty, bile was undersaturated with cholesterol in both sexes to the same extent. After puberty a marked increase in cholesterol saturation was observed in females but not in males (138% vs 88%; P less than 0.01). A significant correlation between age and cholesterol saturation could be observed in females (r = 0.546; P less than 0.05) but not in males. In addition a significant correlation between absolute weight and cholesterol saturation in all females (r = 0.827; P less than 0.001) and those after puberty (r = 0.659; P less than 0.05) could be demonstrated. In neither sex was saturation related to body mass index or ideal body weight. These findings suggest that saturation of bile raises in women during puberty but not in men, and this sex-related difference in cholesterol saturation probably contributes to the more common occurrence of gallstones in women than in men.

Adolescent↗

Mental illness and cognition in relation to age at puberty: a hypothesis.

Onset of puberty is usually considered to coincide with the last major step in brain development: the elimination of some 40% of neuronal synapses. Mean pubertal age has declined by some 4 years during the last 100 years. There is a relation between age at puberty and body build, and between body build and mental illness. The difference in body build between schizophrenia (S) and manic-depressive psychosis (MDP) is similar to that between late and early maturers. It is suggested that S affects late-maturing individuals and MDP very early maturers. The observed marked rise in MDP and decline in the most malignant forms of S (non-paranoid) are in agreement with MDP and S as neurodevelopmental disorders occurring at the extremes of maturation. Maturational irregularities are most likely to occur at the extremes, and it is suggested that abbreviation of the regressive process may have led to persistent redundancy of neuronal synapses in MDP and that prolongation of the process past the optimal has yielded an inadequate synaptic density in S. The lack of cerebral abnormality in the majority of MDP and the presence of only subtle structural deficits in S, are in agreement with this. The two disorders are probably as old as mankind, and early puberty is the necessary factor for the development of MDP and late puberty is the necessary factor for that of S. There is an inverse relation between spatial ability and rate of maturation, whereas verbal ability is unaffected by maturational rate. From a previous predominance in both sexes, spatial ability (Performance IQ scores) has been reduced to below verbal ability (Verbal IQ scores) in the female sex and in early maturing males.

Aging↗

Effects of puberty on seizure frequency.

Seizure frequency was documented before, during and in some cases after puberty for 12 patients with continuing generalised tonic-clonic seizures (GTCS) and for 14 with complex partial seizures (CPS) who were receiving anti-epileptic drugs. For the patients with GTCS there was a significant increase in seizure frequency during the pubertal growth-spurt, with a subsequent decrease after growth ceased. There appeared to be no relationship between puberty and the frequency of CPS. Both groups were more likely to have suboptimal plasma drug-levels during puberty, suggesting that medication was not the cause of the increased GTCS frequency. Further examination of hormonal levels in relation to frequency of GTCS during puberty could provide a better understanding of the influence of hormones.

Adolescent↗

Serum ferritin level as a predictor of impaired growth and puberty in thalassemia major patients.

OBJECTIVE: Previous studies suggested that in patients with thalassemia major, initiating deferoxamine (DFO) therapy before puberty can prevent iron-induced failure of growth and puberty. However, early initiation of chelation has also been associated with DFO toxicity. The aim of this retrospective study was to determine the prevalence rates of endocrine complications and DFO bone toxicity in our thalassemia major patients and to correlate them with the degree of iron chelation. METHODS: Thirty-nine patients with thalassemia major were followed for a median of 16.3 yr (range 2-28). Individual mean serum ferritin level during the study period was calculated using repeated annual measurements. Bone DFO toxicity was assessed by wrist and spine radiographs; endocrine dysfunction by anthropometric measurements and pubertal stage; and hypogonadotropic hypogonadism by lack of luteinizing hormone response to gonadotropin-releasing hormone. RESULTS: Chelation therapy was initiated at median age 4.9 yr. Mean serum ferritin level during the study period was 2698 +/- 1444 ng/mL. Hypogonadism was noted in 59% of the patients who reached pubertal age, and short stature was found in 36% of patients who reached final height. Mean ferritin level of 2500 ng/mL during puberty was the cut-off for hypogonadism, and ferritin level of 3000 ng/mL during prepuberty was the cut-off for final short stature. None of the patients who attained final height had signs of DFO bone toxicity. CONCLUSIONS: High serum ferritin levels during puberty are a risk factor for hypogonadism, and high serum ferritin levels during the first decade of life predict final short stature. It remains to be determined whether improving chelation by earlier initiation of DFO or by the combined use of DFO and deferiprone will lead to better growth and sexual development without DFO toxicity.

Adolescent↗

Blood pressure and body size in precocious puberty.

Blood pressure increases with age in normal children. This increase appears to be related to body size. To assess the role of body size as a determinant of blood pressure in precocious puberty, we compared the blood pressure of 81 children with precocious puberty with the blood pressure standards for normal children from the NHLBI Task Force on Blood Pressure Control in Children. Children with precocious puberty had significantly increased blood pressure for chronologic age (p less than 0.05) but generally appropriate blood pressure for height age or weight age. These data are consistent with the hypothesis that increased body size causes the increased blood pressure for chronologic age in children with precocious puberty. Physicians who evaluate such children should assess whether blood pressure is appropriate for height age rather than chronologic age.

Age Determination by Skeleton↗

Management of growth hormone deficiency through puberty.

As a model of the growth hormone (GH) dependence of growth in prepuberty and puberty, the growth of 182 children (93 boys, 89 girls) who survived in first remission for treatment of acute lymphoblastic leukaemia was examined. Chemotherapy regimens, including intrathecal methotrexate, were similar in all patients, but CNS treatment differed, in that one group received 2400 cGy cranial irradiation, while the other received 1800 cGy. There was a significant decrease in height SDS during prepuberty, which was equivalent in both sexes, whereas there was a much greater decrease in pubertal growth in girls than in boys. Girls treated with the lower dose regimen of cranial irradiation had their onset of pubertal maturation significantly advanced, to a mean of 9.9 years (p less than 0.001). Previous studies have indicated that the duration of puberty is shortened by GH treatment in patients with idiopathic multiple pituitary hormone deficiency or isolated GH deficiency (GHD). To determine whether an increase in the dose of GH administered during the adolescent growth spurt would improve final height, a prospective randomized trial was performed in 32 children (25 boys, 7 girls) with isolated GHD treated with a GH dose regimen of 15 IU/m2/week as daily s.c. injections. At the onset of the pubertal growth spurt, the patients were randomized either to an unchanged dose or to 30 IU/m2/week. There was no significant change in height velocity with the doubled dose of GH, but there was a trend in the advancement of pubertal maturation which was considered to be dose related. It is suggested that these findings are of relevance to the treatment of GHD in puberty, especially in girls with early or precocious puberty occurring as a consequence of low-dose cranial irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

X-linked agammaglobulinemia, growth hormone deficiency and delay of growth and puberty.

Coinheritance of X-linked agammaglobulinemia and growth hormone deficiency (XLA/GHD) has been classified as an independent primary immune deficiency. We evaluated the pattern of growth and endocrine function in seven XLA subjects (ages 10.9-20.1 years); four belonged to two different XLA pedigrees and three represented sporadic XLA cases. Three had reached adulthood (final stature 176.0, 173.5 and 165.0 cm, respectively) and their retrospective growth showed delay in growth and puberty during adolescence. In the other four subjects, growth hormone production was measured by growth hormone pharmacological stimulation tests (clonidine, arginine): three of four patients had insufficient growth hormone responses (peak growth hormone < 10 micrograms/l); all three had delayed puberty; their growth hormone responses increased after "priming" with testosterone, reaching values > 10 micrograms/l in two of them and allowing diagnosis of "true" growth hormone deficiency in the third. The fourth was a normally growing subject who showed a normal growth hormone response both before and after testosterone priming. Six out of the seven subjects showed a growth pattern consistent with delay in growth and puberty. Our results suggest that true XLA/GHD is rarer than previously supposed and that subnormal responses to growth hormone stimulation tests may be found without sex steroid priming of the test in adolescence. The most probable growth pattern in XLA appears to be delay in growth and puberty, as has already been described for other chronic diseases.

Adult↗

Insulin: the other anabolic hormone of puberty.

To determine the effect of puberty on insulin action, we used the euglycaemic-hyperinsulinaemic clamp technique in combination with stable isotopes and indirect calorimetry in lean pre-adolescents, adolescents and adults. These studies indicated that the insulin resistance induced by normal puberty alters glucose metabolism but is insufficient to adversely affect insulin-stimulated protein metabolism or to inhibit lipolysis. Using the hyperglycaemic clamp technique, we evaluated the impact of the insulin resistance on insulin secretion in pre-adolescents, adolescents and young adults. These studies revealed that the insulin and C-peptide responses to a standardized intravenous hyperglycaemic stimulus were two- to threefold greater in adolescents than in pre-adolescent children and adults. As growth hormone (GH), insulin-like growth factor I (IGF-I) and insulin levels normally peak during puberty, we examined the influence of insulin on IGF-I regulation by measuring basal GH, total and free IGF-I, and IGF binding protein (IGFBP) levels in lean adolescents and young adults. During the clamp studies, the adolescents exhibited low levels of IGFBP-1 and -2 as well as a reduced insulin-induced suppression of IGFBP-1, compared with lean adults. Thus, we postulate that the insulin resistance of puberty induces compensatory hyperinsulinaemia, which in turn suppresses circulating levels of IGFBP-1, which in turn leads to increased levels of free IGF-1.

Adolescent↗

Precocious puberty in girls: early diagnosis of a slowly progressing variant.

An attempt was made to identify the less severe cases of precocious puberty and to describe their natural course. A group of 17 girls with precocious puberty and a bone age advance over chronological age of less than two years (group 1) was compared with a group of 19 patients with severe precocious puberty and bone age advance of two years or more (group 2). Mean (SEM) plasma oestradiol concentrations were 82 (30) pmol/l and 164 (21) pmol/l (p less than 0.05), vaginal maturation indexes were 16 (5) and 41 (4), and plasma somatomedin C concentrations were 1.0 (0.2) U/ml (n = 8) and 2.1 (0.3) U/ml (n = 16) in groups 1 and 2, respectively. The time between onset and diagnosis of secondary sexual characteristics was about one year in both groups. After two years' follow up the untreated patients in group 1 had maintained their predicted final height. These changes were in contrast to those observed at first examination in patients in group 2 who had a mean (SD) predicted final height of -1.3 (0.2) and a mean bone age advance of 3.0 (0.2) years. These data show that bone age advance to chronological age, and plasma somatomedin C concentrations measured at initial evaluation are helpful in identifying less severe and potentially slow progressing forms of central precocious puberty.

Age Determination by Skeleton↗

Oral treatment for constitutional delay of growth and puberty in boys: a randomised trial of an anabolic steroid or testosterone undecanoate.

Thirty three boys (mean 14.6 years old, range 12.8-16.2 years) with constitutional delay of growth and puberty were randomised into two groups to determine which form of oral treatment would give the better anthropometric response. The two drugs were administered by mouth (one tablet/day) for a mean of 3.5 months (range 3-7 months). At randomisation, 17 boys received testosterone undecanoate (40 mg/day) and 16 oxandrolone (2.5 mg/day). At the start of treatment they were prepubertal or in early puberty, their height SD score was -1.97 in boys treated with testosterone and -2.21 in those treated with oxandrolone, and their growth rates were 4.3 and 4.2 cm/year respectively. Both sex steroid and anabolic steroid treatments induced a significant growth acceleration in all patients except four (three treated with testosterone and one with oxandrolone). When treated with the alternative sex steroid, all four non-responders had a significant anthropometric response. In all boys the induced growth acceleration was sustained when treatment was interrupted. There was no significant difference in the induced growth spurt and bone maturation between the two groups. Spontaneous progress into puberty was achieved in all boys with an increase in testicular volume from a mean of 4.6 to 8.5 ml. The rate of development in secondary sexual characteristics was also similar in the two groups. These data suggest that oral testosterone and oxandrolone are equally effective in the treatment of growth delay in boys with constitutional delay of growth and puberty.

Administration, Oral↗

Changes in the male voice at puberty.

The changes in the male voice in relation to the biological characteristics of puberty were assessed longitudinally in 26 boys. Speaking and singing fundamental frequencies were analysed in relation to the Tanner staging of puberty, saliva testosterone levels, and the Cooksey classification of voice analysis. There were abrupt changes in voice characteristics between Tanner stages G3 and G4 and more gradually from stages C3 to C5 of Cooksey. Although testosterone concentrations were not predictive of the changes, there was a correlation with testis volume. Voice fundamental frequencies were seen to change abruptly in late puberty, in contrast with previous studies. There is a good correlation between the Tanner and Cooksey methods of classification during male puberty.

Adolescent↗

Outcome of premature thelarche: relation to puberty and final height.

BACKGROUND: There is a debate about the possible progression of idiopathic premature thelarche towards precocious or early puberty. OBJECTIVE: To evaluate height and age at onset of puberty in a group of girls with a history of idiopathic premature thelarche. STUDY DESIGN: The height and age at onset of puberty of 42 girls now over 10 years of age who were diagnosed with isolated premature thelarche before the age of 3 years were evaluated. RESULTS: Menarche was reached before or at 11 years of age in 13.5% of this group of girls. This percentage of early menarche was higher than would be expected from historical controls in the general population, but was consistent with maternal age of menarche. The mean (SD) height of the girls (n = 15) who achieved adult height was 162.9 (6.3) cm, which was slightly higher than the mean (SD) relative mid-parental height (160.7 (6.7) cm). CONCLUSIONS: Isolated premature thelarche with onset before 3 years of age progresses towards precocious puberty, although this was consistent with the maternal age of menarche. Furthermore, adult height was normal when compared with population norms in all patients.

Adolescent↗

An increase in in vivo release of LHRH and precocious puberty by posterior hypothalamic lesions in female rhesus monkeys (Macaca mulatta).

We have previously shown that a decrease in gamma-aminobutyric acid (GABA) tone and a subsequent increase in glutamatergic tone occur in association with the pubertal increase in luteinizing hormone releasing hormone (LHRH) release in primates. To further determine the causal relationship between developmental changes in GABA and glutamate levels and the pubertal increase in LHRH release, we examined monkeys with precocious puberty induced by lesions in the posterior hypothalamus (PH). Six prepubertal female rhesus monkeys (17.4 +/- 0.1 mo of age) received lesions in the PH, three prepubertal females (17.5 +/- 0.1 mo) received sham lesions, and two females received no treatments. LHRH, GABA, and glutamate levels in the stalk-median eminence before and after lesions were assessed over two 6-h periods (0600-1200 and 1800-2400) using push-pull perfusion. Monkeys with PH lesions exhibited external signs of precocious puberty, including significantly earlier menarche in PH lesion animals (18.8 +/- 0.2 mo) than in sham/controls (25.5 +/- 0.9 mo, P<0.001). Moreover, PH lesion animals had elevated LHRH levels and higher evening glutamate levels after lesions, whereas LHRH changes did not occur in sham/controls until later. Changes in GABA release were not discernible, since evening GABA levels already deceased at 18-20 mo of age in both groups and morning levels remained at the prepubertal levels. The age of first ovulation in both groups did not differ. Collectively, PH lesions may not be a good tool to investigate the mechanism of puberty, and, taking into account the recent findings on the role of kisspeptins, the mechanism of the puberty onset in primates is more complex than we initially anticipated.

Aging↗

Diabetic kidney disease: impact of puberty.

Puberty accelerates microvascular complications of diabetes mellitus, including nephropathy. Animal studies confirm a different renal hypertrophic response to diabetes before and after puberty, probably due to differences in the production of transforming growth factor-beta (TGF-beta). Many of the complex physiological changes during puberty could affect potentially pathogenic mechanisms of diabetic kidney disease. Increased blood pressure, activation of the growth hormone-insulin-like growth factor I axis, and production of sex steroids could all play a role in pubertal susceptibility to diabetic renal hypertrophy and nephropathy. These factors may influence the effects of hyperglycemia and several systems that ultimately control TGF-beta production, including the renin-angiotensin system, cellular redox systems, the polyol pathway, and protein kinase C. These phenomena may also explain gender differences in kidney function and incidence of end-stage renal disease. Normal changes during puberty, when coupled with diabetes and superimposed on a genetically susceptible milieu, are capable of accelerating diabetic hypertrophy and microvascular lesions. A better understanding of these processes may lead to new treatments to prevent renal failure in diabetes mellitus.

Adolescent↗

Gonadotrophin-independent puberty in a boy with a beta-HCG-secreting brain tumour.

We report on a short-statured boy in whom therapy with recombinant human growth hormone was initiated at the age of 9.7 years for assumed idiopathic growth hormone deficiency. On recombinant human growth hormone, height improved from -1.9 (standard deviation score) to -0.9 within 1 year, and the patient entered puberty spontaneously at 10.7 years. At 11.6 years he showed low morning cortisol and thyroxine levels, but was otherwise well. He showed an inconspicuous growth, and puberty progressed adequately until the age of 13.4 years, when he developed signs of an increased intracranial pressure, and a suprasellar choriocarcinoma was diagnosed. This case confirms the fact that beta chorionic gonadotrophin secreting tumours will not be diagnosed by the characteristic clinical manifestation of gonadotrophin-independent puberty if they occur at a time when normal puberty is expected. Particularly, it raises the question of how often the CNS should be re-evaluated by magnetic resonance imaging in children with growth hormone deficiency and normal initial neuroradiological imaging, when they develop additional hormonal deficiencies but no other clinical symptoms of an intracranial process.

Adolescent↗

Effect of puberty on the relationship between bone markers of turnover and bone mineral density in Turner's syndrome.

It has been suggested that the appropriate timing of puberty is necessary for normal bone mineral acquisition which may not be achieved amongst patients with Turner's syndrome (TS). The aim of this study was to assess bone mineral density (BMD) and bone turnover in 34 patients with TS (age range 2.2-39.0 years). The areal BMD (aBMD) was determined by dual-energy X-ray absorptiometry, and the volumetric BMD was calculated. Blood and second voided urine samples were taken the morning after an overnight fast for evaluation of the biochemical markers of bone turnover: bone-specific alkaline phosphatase (BAP) and N-telopeptides of type I collagen (NTX), respectively. Both were determined by enzyme-linked immunosorbent assay. The patients were divided into three groups: group 1 (n = 13; prepubertal; age range 2.2-19.0 years), group 2 (n = 10; teenagers; age range 12.4-19.0 years), and group 3 (n = 11; adults; chronological age >20 years). They were also grouped by breast development according to Tanner stage into B1 (n = 12), B2-3 (n = 9), and B4-5 (n = 13). The aBMD was significantly lower in group 1 and was higher at Tanner stages 4 and 5 as compared with patients at Tanner stage 1. The bone turnover markers were significantly higher in group 1 (NTX: p = 0.002; BAP: p = 0.0005) and declined, as puberty progressed. A negative correlation was observed between aBMD and biochemical bone markers at the lumbar spine (NTX: r = -0.54, p = 0.05; BAP: r = -0.44, p = 0.01) and in the whole body (NTX: r = -0.60, p = 0.0008; BAP: r = -0.19, p = 0.002). We conclude that the negative relationships between aBMD and biochemical markers suggest a high bone turnover, mainly in prepubertal patients and that the results observed in relation to aBMD and puberty are imputed to the delayed puberty which occurs amongst TS patients.

Absorptiometry, Photon↗