Biomedical subjects

A Ruokonen

Publications and source records attributed to A Ruokonen.

At least 37 records · Page 2Linked to original sources

PubMed2000

Effects of seasonal photoperiod on serum 25-hydroxycholecalciferol and calcium in reindeer, Rangifer tarandus tarandus.

In order to understand the effects of solar irradiance on calcium metabolism we measured serum 25-hydroxycholecalciferol and total calcium levels monthly in 6 female nonpregnant reindeer maintained in the Oulu area (65 degrees N). Mean monthly serum total calcium levels varied slightly and the highest levels were seen in October. Serum 25-hydroxycholecalciferol levels were highest in October but the monthly variation was also slight. The small monthly variation of the analytes' abundance and the fact that they peaked not until 4 months after the longest day, (i.e. the main stimulus for vitamin D synthesis) could have something to do with the supplementation of this vitamin in the diet of the captive reindeer.

Animals↗

PubMed1999

Low serum inhibin B concentrations in male survivors of childhood malignancy.

The aim of this study was to assess the value of serum inhibin B in detecting male gonadal dysfunction in childhood cancer survivors. 27 male postpubertal (Tanner's pubertal stage G5 or P6) and 12 pubertal (> or = G2) patients were drawn from the endocrine follow-up protocol of childhood cancer patients at the Paediatric Clinic of Turku University Hospital, Turku, Finland. The average time (mean +/- S.D.) between the diagnosis and this study was 11.7 +/- 4.5 years in the postpubertal and 7.0 +/- 3.9 years in the pubertal group. Serum samples for the determination of follicle-stimulating hormone (FSH), luteinising hormone (LH), oestradiol, testosterone, and inhibin A and B dimers were collected. The demographic factors, pubertal stage and testicular size of the patient were measured at the same routine outpatient visit. Serum inhibin concentrations were correlated to testicular volume and gonadotrophin concentrations. Strong correlations were observed between testicular size (r = 0.80, P < 0.001) or FSH (r = -0.58, P = 0.002) and inhibin B concentration in the postpubertal group. Inhibin A was not detectable (< 2 pg/ml). Testicular volume measurement was accurately documented in 21 postpubertal subjects. Patients with small testicles (< 10 ml) had inhibin B concentrations under 42 pg/ml and those whose testicular size was over 13 ml had inhibin B concentrations exceeding 100 pg/ml. In all 12 pubertal survivors, serum inhibin B levels were > or = 94 pg/ml, except in one case of testicular cancer where inhibin B was 8.1 pg/ml and the FSH concentration was elevated. Inhibin B seems to be an indicator of male gonadal function in postpubertal childhood cancer survivors and could be used in the estimation of gonadal function of male survivors earlier than testicular volume or semen analyses would be routinely possible. However, the correct cut-off level of serum inhibin B, as well as the details of inhibin B physiology during puberty, remain to be determined before semen analysis can be replaced by the measurement of inhibin B.

Adolescent↗

PubMed1999

Neuroendocrine responses to psychological workload of instrument flying in student pilots.

BACKGROUND: Information processing and stress tolerance are necessary features for instrument flying (IFR), especially among student pilots. Psychological workload of IFR flight may lead to stress reactions such as neuroendocrine activity. METHODS: Neuroendocrine responses to an IFR flight with Vinka piston-engined primary trainer were studied in 35 male volunteers who participated in the basic military flying course of the Finnish Air Force (FAF). The student pilots performed a 40-min IFR flight mission and a control session on land in randomized order between 11.00 h and 15.00 h. The IFR flight included 3 NDB approaches and was evaluated by flight instructors. Blood samples were collected 15 min before, 5 min and 60 min after the flight as well as control session, and. Plasma ACTH, beta3-endorphin (BE), cortisol, prolactin, adrenaline (A) and noradrenaline (NA) were measured. Psychological evaluations included psychomotor test (Wiener), Multi Coordination and Attention Test, ability tests and personality tests (CMPS and 16 PF). The overall psychological evaluation was made by an aviation psychologist. RESULTS: Plasma ACTH was significantly higher before and 5 min after the flight compared with control levels, but plasma BE increased significantly only before the flight. Plasma cortisol was significantly elevated before and 5 min after the flight. Plasma prolactin, NA and A increases were significant 5 min after the flight. High A levels after the flight correlated significantly with poor IFR flight performance as well as with poor psychomotor test results. CONCLUSIONS: The plasma prolactin and NA increases after the flight represented a direct type of stress reaction to the flight situation. The plasma BE response to IFR flight was an anticipatory stress reaction, but plasma ACTH, cortisol and A responses included both anticipatory and direct types of stress reactions. Psychological factors, flight performance and neuroendocrine responses to IFR flight appear to be associated with each other. Therefore, neuroendocrine reactions as a response to the psychological workload of military flying could be used for identifying stress tolerance in military pilots.

Adrenocorticotropic Hormone↗

PubMed1999

Neuroendocrine responses and psychomotor test results in subjects participating in military pilot selection.

BACKGROUND: Military flying sets high demands on the mental performance and stress tolerance of pilots. Neuroendocrine responses could be a method for evaluating stress tolerance. METHODS: Psychological workload and neuroendocrine responses associated with the psychomotor Wiener's test were studied in 80 male volunteers. These personnel had applied for the basic military flying program of the Finnish Air Force (FAF). After the first blood sample at 0930 h, the subjects were randomly assigned to test (n = 40) and control groups (n = 40). The test group performed the psychomotor test, which lasted 10 min. The second blood sample was collected 1 min after the test. The control group was clinically examined and the blood sample was taken in the same way. RESULTS: A high plasma ACTH level before the psychomotor test predicted (r = 0.36, p = 0.02) a poor overall result in the psychomotor test. After the psychomotor test, plasma adrenocorticotropin (ACTH) and beta-endorphin levels were significantly higher than before the test. They were also higher than in the control group. Plasma cortisol and prolactin levels increased after the psychomotor test, but the increase was not statistically significant. High ACTH, cortisol and prolactin increments were specific to a high amount of delayed (over 2 s) psychomotor responses, as a marker of information overload. CONCLUSIONS: Elevated plasma ACTH, cortisol and prolactin levels, after the psychomotor test, were associated with a high amount of the delayed responses. This indicates that high neuroendocrine responses were connected with problems in stress tolerance during information processing. High neuroendocrine reactions under information load could, therefore, be used for identification of lowered stress tolerance.

Adolescent↗

PubMed1998

Elevated serum inhibin and tumor-associated trypsin inhibitor concentrations in a young woman with dysgerminoma of the ovary.

We describe a patient with dysgerminoma who had elevated serum inhibin, tumor-associated trypsin inhibitor (TATI), and CA 125 concentrations, which increased progressively during follow-up of the advancing disease. Inhibin levels correlated closely with disease behavior. In contrast to inhibin, serum TATI and CA 125 failed to reveal the presence of silent disease.

Adult↗

PubMed1998

Metformin therapy improves the menstrual pattern with minimal endocrine and metabolic effects in women with polycystic ovary syndrome.

OBJECTIVE: To determine the clinical, hormonal, and biochemical effects of 4-6 months of metformin therapy in obese patients with polycystic ovary syndrome (PCOS). DESIGN: Prospective study. SETTING: The Gynecological Endocrine Unit of University Central Hospital, Oulu, Finland. PATIENT(S): Twenty obese patients with PCOS. INTERVENTION(S): Patients were treated with 0.5 g of metformin three times daily for 4-6 months. MAIN OUTCOME MEASURE(S): Clinical symptoms, menstrual pattern, and hirsutism, as well as serum concentrations of sex steroids, sex hormone-binding globulin (SHBG), gonadotropins, and lipids were assessed during the treatment. RESULT(S): Eleven women (68.8% of the women with menstrual disturbances) experienced more regular cycles during therapy. No changes in hirsutism, body mass index, or blood pressure occurred. The mean testosterone level was decreased significantly after 2 months of treatment but returned to the starting level by 4-6 months. Free testosterone levels decreased significantly during the treatment. There was no significant change in the levels of other sex steroids or lipids measured at 4-6 months of treatment. CONCLUSION(S): Metformin therapy is well tolerated by the majority of patients and may be clinically useful, especially in obese patients with PCOS and menstrual disturbances.

17-alpha-Hydroxyprogesterone↗

PubMed1998

Decreased serum leptin concentrations during metformin therapy in obese women with polycystic ovary syndrome.

Previous studies have suggested that metformin is clinically useful in the treatment of polycystic ovary syndrome (PCOS). The aim of this study was to evaluate whether the improvement of ovarian function achieved by metformin therapy is associated with changes in leptin concentrations. Twenty-six obese women with PCOS were treated with 500 mg metformin, x 3 daily, for 2 months; and 12 women continued the therapy for 4-6 months. A significant decrease in the serum leptin level was observed after 2 months of treatment in the whole study group (29.2 +/- 12.7 ng/mL vs. 25.7 +/- 10.9 ng/mL, P = 0.03). In the 12 women treated for 4-6 months, the mean serum leptin concentration decreased after 2 months (38.6 +/- 9.3 ng/mL vs. 30.2 +/- 8.1 ng/mL; P = 0.004) but slightly increased after 4-6 months of treatment (33.4 +/- 15.7 ng/mL; not significant). These results indicate that insulin sensitizing therapy with metformin decreases the leptin concentrations in obese PCOS women.

Adult↗

PubMed1998

Pituitary function in children with hydrocephalus before and after the first shunting operation.

OBJECTIVE: Children with shunted hydrocephalus experience slow linear growth in prepuberty, accelerated pubertal maturation and a reduced final height. A substantial proportion of these patients have a poor growth hormone (GH) response to stimulation and reduced pituitary volume. The basic mechanisms behind these phenomena are still unknown, but one can hypothesize that an unphysiological intracranial pressure (ICP) may be involved. This study was undertaken to investigate the effect of increased ICP on pituitary function. DESIGN: Twenty-one children (nine males) aged 4 months to 15 years were evaluated for pituitary function before and after their first shunting operation. METHODS: A clinical examination was performed, bone age was determined and a combined pituitary stimulation test was performed to evaluate GH, luteinizing hormone, follicle-stimulating hormone, cortisol, thyrotropin and prolactin secretion. RESULTS: GH concentrations were significantly higher 10 and 15 min before the operation (P=0.04 and P=0.03 respectively) than after it. The basal levels of insulin-like growth factor-I (IGF-I) tended to be higher before the operation than afterwards and those of its binding protein-3 (IGFBP-3) were significantly so (P<0.01). CONCLUSIONS: The higher GH response to GH releasing hormone and circulating IGFBP-3 levels in children with hydrocephalus before compared with after their first shunting operation raise the possibility that the reduced GH secretion and retarded linear growth observed in children with shunted hydrocephalus may be a consequence of decreased ICP and/or the lack of physiological pressure variations.

Adolescent↗

PubMed1998

Pro-opiomelanocortin activation and simulated interceptor combat flight.

METHODS: To investigate the influence that psychological workload, associated with simulated combat military flight, has on secretion of stress hormones we measured concentrations of plasma corticotropin-releasing hormone (CRH), pro-opiomelanocortin (POMC) related adrenocorticotropin (ACTH), beta-endorphin (BE), and cortisol in 10 Finnish Air Force (FAF) military interceptor pilots. They performed the same 20-min combat flight mission in a Saab J35 Draken S simulator, including four radar attacks during one-on-one situations with increasing cognitive tasks and psychological strain. Blood samples were collected -35 min, 1 min, 30 min and 60 min after the flight mission. Control blood samples were collected from the subjects at the same time of day in randomized order before or after the flight mission. During the control period the subjects were allowed to perform ground duties. RESULTS: Plasma CRH was undetectable in samples drawn before or after the flight and control period. Plasma ACTH was significantly (p < 0.05) elevated before the simulated combat flight when compared with the respective value in the control experiment. This is an anticipatory type of stress reaction. Plasma BE did not change significantly after the simulated flight. Plasma cortisol increased significantly (p < 0.05) 1 min after the simulated flight. One of the ten pilots had an extreme POMC and cortisol activation after the flight mission, suggesting that the pilot's stress tolerance was less than average. CONCLUSIONS: We conclude that stress, produced during simulated combat military flight, increases POMC and cortisol secretion. An anticipatory-type stress reaction was found to be associated with the simulated combat flight, as judged from the increased preflight plasma ACTH.

Adrenocorticotropic Hormone↗

PubMed1998

Polycystic ovary syndrome and hyperandrogenism as a risk factor for cardiovascular disease.

About 30% of infertility is caused by anovulation, associated most commonly with the polycystic ovary syndrome (PCOS). PCOS is a common endocrinopathy in women, especially at the age of 30 to 35 years, characterized by irregular menses, infertility and signs of hyperandrogenism. The pathogenetic mechanisms leading to PCOS are not fully understood, although several theories have been proposed. PCOS patients commonly have hyperinsulinemia and insulin resistance which are also known risk factors for the development of diabetes mellitus, hypertension and cardiovascular disease. However, it is not known, how well the presence of PCOS symptoms would predict the appearance of the long-term sequelae of insulin resistance. Also more data is needed e.g. of the role of intrauterine factors and birth weight in the development of PCOS and hyperandrogenism.

Adult↗

PubMed1997

Pituitary size and function in children and adolescents with shunted hydrocephalus.

OBJECTIVE: Most previous reports of endocrine disorders in children with shunted hydrocephalus have been case reports and there is a lack of systematic information on pituitary anatomy and function among these children. We have obtained these data in a large group of individuals with shunted hydrocephalus. DESIGN: A controlled cross-sectional study. PATIENTS: Fifty-four children and adolescents with shunted hydrocephalus were studied for pituitary anatomy and function. They had 54 age- and sex-matched controls (group I). The mean age of the patients and controls was 12.6 years and the mean shunting period 10.6 years. There was a second control group (II) for the magnetic resonance imaging (MRI) and a third control group (III) for the radiography of the sella turcica. MEASUREMENTS: The anatomy was visualized by MRI of the pituitary gland and by radiography of the sella turcica. The functional evaluation included an arginine-insulin test and a combined stimulation test with corticotrophin releasing factor (CRF), GnRH and TRH. RESULTS: The patients were shorter (height 148.4 cm vs 153.7 cm, P < 0.05 and relative height -0.5 SDS vs 0.4 SDS, P < 0.05) and had a higher BMI than the control group I (20.6 kg/m2 vs 18.0 kg/m2, P < 0.001). They had also a greater pituitary height than the control group II (5.8 mm vs 5.1 mm, P < 0.01). The patients had significantly lower basal GH levels (P < 0.001) than controls I. Sixteen patients (30%) had a poor GH response (< 20 mU/l) in the arginine-insulin test. Pituitary height was significantly lower among these patients than in those with a normal response (4.7 mm vs 6.3 mm, P < 0.01), who had an increased pituitary height compared to controls II (5.1 mm, P < 0.01). The area under the curve (AUC) for GH correlated with the pituitary volume (r = 0.50, P < 0.001). The patients had higher basal FSH and LH concentrations than controls I (P < 0.001). The peak to basal ratios of FSH and LH were increased in the prepubertal patients and that of LH at Tanner pubertal stage II in the females. The basal FSH and LH levels correlated with the pituitary volume (r = 0.50 and r = 0.54, P < 0.001 for), as did FSH AUC and LH AUC (r = 0.48 and r = 0.75, P < 0.001 for both). CONCLUSIONS: These observations indicate that children with shunted hydrocephalus have an increased pituitary size on average. About one-third of these patients had signs of reduced GH secretion and significantly lower pituitary height, which probably contributes to their poor linear growth. Increased pituitary size was associated with enhanced gonadotrophin secretion, which may result in early puberty in children with shunted hydrocephalus.

Adolescent↗

PubMed1997

Insulin-like growth factors and their binding proteins in the venous effluents of ovary and adrenal gland in severely hyperandrogenic women.

Insulin and insulin-like growth factors (IGF) are thought to play an important role in the pathogenesis of excessive androgen production. To explore this question further we measured the concentrations of IGF-I and -II and their binding proteins (IGFBP-1 and-3) in adrenal and ovarian vein samples of severely hyperandrogenic women (serum testosterone > 5 nmol/l) collected as part of their diagnostic work-up. The concentration of IGF-II was slightly but not significantly higher in the ovarian vein than in the adrenal and peripheral veins. The concentrations of IGF-I and IGFBP were identical in both the adrenal and ovarian veins and did not differ from those in the peripheral circulation. The concentration of IGFBP-1 was negatively correlated (r = -0.60, P > 0.05) with insulin and IGFBP-3 showed a strong positive correlation with IGF-1 (r = 0.90, P > 0.01). These results indicate that neither the ovary nor the adrenal gland contributes significantly to the circulating pool of IGF or their binding proteins in severely hyperandrogenic subjects. Hyperinsulinaemia is associated with low circulating IGFBP-1 concentrations and IGFBP-3 seems to be an excellent indicator of the peripheral IGF-I concentration. The concentrations of IGF-I suggested decreased somatotrophic activity in these obese, hyperinsulinaemic subjects.

Adrenal Glands↗

PubMed1997

Reduced levels of growth hormone, insulin-like growth factor-I and binding protein-3 in patients with shunted hydrocephalus.

OBJECTIVE: Children with hydrocephalus are characterised by slow linear growth in prepuberty, accelerated physical maturation during puberty, and reduced final height. We aimed to study the possible roles of growth hormone, insulin-like growth factor-I (IGF-I), and IGF binding protein-3 (IGFBP-3) in this growth pattern. STUDY DESIGN: One hundred and fourteen patients with shunted hydrocephalus (62 males) aged 5 to 20 years, of whom 17 had spina bifida (six males), and 73 healthy controls (38 males) were studied. Anthropometric measures, body mass index, and body fat mass were assessed and the stage of puberty was determined. Serum growth hormone and plasma IGF-I and IGFBP-3 concentrations were measured. RESULTS: The patients comprised 44 (26 males) who were prepubertal and 70 (36 males) pubertal or postpubertal, while 32 of the controls (19 males) were prepubertal and 41 (19 males) pubertal or postpubertal. The prepubertal children with hydrocephalus had lower IGF-I (p = 0.002) and IGFBP-3 concentrations (p < 0.001) than the controls, and the pubertal children had four times lower basal growth hormone concentrations (p < 0.001). There was a correlation between height SD score and IGF-I levels in the total patient population (r = 0.23; p = 0.01). Peripheral IGF-I concentrations peaked at pubertal stages 2-3 in the female patients and at stage 4 in the controls. The prepubertal patients on antiepileptic treatment, carbamazepine in most cases (73%), had higher IGF-I (p = 0.01) and IGFBP-3 concentrations (p = 0.03) than those who had never been treated with antiepileptic drugs, but still lower IGFBP-3 levels than the controls (p = 0.01). CONCLUSION: Based on these findings, it can be concluded that reduced growth hormone secretion may contribute to the pattern of slow linear growth and reduced final height observed in these patients.

Adolescent↗

PubMed1997

Isotretinoin, tetracycline and circulating hormones in acne.

Isotretinoin, used to treat severe acne, has been shown to induce hormonal changes, especially to reduce 5 alpha-reductase in the production of the tissue-derived dihydrotestosterone (DHT) metabolite 3 alpha-Adiol G. However, the effects of isotretinoin on other pituitary, adrenal or gonadal hormones have not been thoroughly elucidated. In the present study, isotretinoin administered at a dose of 0.5 mg/kg/day for 4 weeks caused no marked changes in the serum levels of pituitary, adrenal or gonadal hormones or 3 alpha-Adiol G in patients with severe papulopustulotic acne (n = 19). After 12 weeks of therapy, there was a decrease in the levels of the precursor androgens androstenedione, testosterone and 3 alpha-Adiol G in 6/9 patients. Acne improved after 4.5 months in all but 2 male patients, who had very low serum hormone binding globulins (SHBG) and a high free androgen index (FAI). Isotretinoin did not affect the elevated LH/FSH ratio in a patient with the polycystic ovarian syndrome (PCOS); nor did it change the high FAI or low SHBG in the male patients. For comparison, tetracycline had no effects on the serum hormonal levels of patients with mild acne (n = 19) after 7 days of treatment. This study confirms that the effects of isotretinoin on the serum hormone levels are small and unlikely to be of relevance for the resolution of acne or the suppression of sebum excretion.

Acne Vulgaris↗

PubMed1996

Seasonal changes in pituitary function: amplification of midfollicular luteinizing hormone secretion during the dark season.

OBJECTIVE: To analyze the effect of season on the pulsatility of gonadotropin secretion in women living in an area with a large annual variability in daylight length. DESIGN: A prospective study. Pulse studies were carried out in each subject during both the dark and light season. SETTING: The gynecologic endocrine research unit of the University Central Hospital of Oulu. PARTICIPANTS: Eleven ovulatory, healthy women volunteering for the study. INTERVENTIONS: Serum samples were collected at 10-minute intervals for 6 hours on days 7 to 9 of the cycle. MAIN OUTCOME MEASURES: Serum LH and FSH concentrations were measured and the data were analyzed with an algorithm computer-based program. RESULTS: The mean area of LH pulses analyzed was significantly higher during the dark season than the light season (49.1 +/- 3.1 versus 38.5 +/- 1.7 mIU/mL; conversion factor to SI unit, 1.00), while in the amplitude (1.9 +/- 0.1 versus 1.8 +/- 0.1 mIU/mL), number of pulses (5.2 +/- 0.3 versus 4.4 +/- 0.6), and the mean level (9.6 +/- 0.5 versus 9.4 +/- 0.9 mIU/mL) the difference did not reach statistical significance. The number (5.2 +/- 0.5 versus 5.2 +/- 0.4,), amplitude (1.0 +/- 0.05 versus 1.1 +/- 0.07 mIU/mL; conversion factor to SI unit, 1.00), area (29.9 +/- 2.4 versus 29.6 +/- 3.1 mIU/mL), and the mean level of FSH (5.4 +/- 0.6 versus 6.0 +/- 0.8 mIU/mL) during the dark and light seasons were identical, showing no seasonal variability. CONCLUSIONS: The results indicate increased pituitary LH secretion in the midfollicular phase during the dark season that may be related to increased melatonin secretion and decreased ovarian activity at this time of the year.

Adult↗

PubMed1996

Adrenal steroidogenesis is related to insulin in hyperandrogenic women.

OBJECTIVE: To evaluate ovarian and adrenal steroid secretion in women with severe hyperandrogenism. DESIGN: A prospective study. SETTING: The Gynecological Endocrine Research Unit of the University Central Hospital, Oulu, Finland. PATIENTS: Thirteen obese, hirsute women with severe hyperandrogenism. INTERVENTIONS: Adrenocorticotropin hormone stimulation and dexamethasone suppression tests and selective catheterizations of the left ovarian and adrenal veins were performed. MAIN OUTCOME MEASURES: The concentrations of insulin, P, 17-hydroxyprogesterone (17-OHP), androstenedione (A), T, DHEA, DHEAS, and cortisol were measured. RESULTS: The secretory gradients of T and its precursors, P, 17-OHP, A, and DHEA in the selective catheterizations showed the adrenal to be the main source of excessive steroid production in these patients. The concentrations of P (r = 0.82), 17-OHP (r = 0.89), A (r = 0.84), T (r = 0.86), and cortisol (r = 0.87) in the adrenal vein showed a strong correlation with insulin measured from the same samples. CONCLUSIONS: Excessive androgens were secreted mainly by the adrenals in these obese hyperinsulinemic women. Correlation analyses suggested that insulin stimulates adrenal androgen and cortisol secretion, which may constitute an important component of the pathogenetic mechanisms of hyperandrogenism and the polycystic ovary syndrome.

Adolescent↗

PubMed1996

Accelerated pubertal development in patients with shunted hydrocephalus.

OBJECTIVE: To evaluate pubertal development and peripheral concentrations of gonadotrophins and sex hormones in children with shunted hydrocephalus compared with healthy controls. STUDY DESIGN: 114 patients (52 females, 62 males) and 73 healthy controls (35 females, 38 males) aged 5 to 20 years were analysed for stage of puberty, age at menarche, testicular volume, basal serum follicle stimulating hormone (FSH), luteinising hormone (LH), sex hormone binding globulin (SHBG), testosterone and oestradiol concentrations, and free androgen index. RESULTS: Male gonadal and male and female pubic hair development occurred significantly earlier in the patients than in the controls. The mean age at menarche was significantly lower in the female patients than in their controls (11.7 v 13.2 years; p < 0.001), and lower than it had been for their mothers (v 13.1 years; p < 0.001). Relative testicular volume was higher in the male patients than in their controls (1.2 standard deviation score (SDS) v 0.2 SDS; p < 0.001). The prepubertal patients had higher basal LH (0.13 U/l v 0.08 U/l; p < 0.001) and SHBG (132.3 nmol/l v 109.1 nmol/l; p < 0.01) than the controls. Both the prepubertal and pubertal females had significantly higher basal FSH than their controls (1.57 U/l v 1.03 U/l; p < 0.05, and 4.0 U/l v 2.9 U/l; p < 0.01, respectively). CONCLUSIONS: Hydrocephalic children experience accelerated pubertal maturation, reflected in a younger age at menarche in females and an increased testicular volume in males. This may be because of enhanced gonadotrophin secretion, possibly resulting from unphysiological variations in intracranial pressure.

Adolescent↗

PubMed1996

Ethanol decreases nocturnal plasma levels of thyrotropin and growth hormone but not those of thyroid hormones or prolactin in man.

Previous studies on the effects of ethanol on circulating pituitary hormones have been carried out mostly during daytime when the secretion of these hormones is generally at a nadir. Therefore, we studied the effects of ethanol on the nocturnal secretion of GH, PRL, TSH, and thyroid hormones (protocol I, nine healthy subjects, five women) and on the TSH and PRL responses to synthetic TRH (protocol II, healthy subjects, four women). Ethanol was given in doses of 0, 0.5 or 1.0 g/kg of BW(protocol I) and 0 or 1.0 g/kg (protocol II) and ingested po at 1900-1945 h. In protocol I, plasma GH rose from 0.6 +/- 0.2 microgram/L (mean +/- SE) at 2200 h to 25.0 +/- 4.3 micrograms/L at 0100 h in control subjects and was almost completely inhibited at 4.5 +/- 1.7 micrograms/L at 0100 h in subjects receiving 1.0 g/kg ethanol (P < 0.01). In subjects receiving 0.5 g/kg ethanol, the inhibition was also significant (P < 0.01), plasma GH being 8.2 +/- 2.5 micrograms/L at 0100 h. Plasma GHRH was measured after solid phase separation in RIA, but it did not show any ethanol-related changes. Plasma PRL exhibited a clear diurnal rhythm in control subjects and rose from 77 +/- 16 at 1800 h to 248 +/- 62 micrograms/L at 0700 h (P < 0.01). The plasma PRL profile was not affected by ethanol. Plasma TSH was 1.4 +/- 0.2 mU/L at 1800-2200 h and rose to 2.3-2.4 mU/L for 0100-0700 h (P < 0.001) in the control subjects. Ethanol 1.0 g/kg suppressed plasma TSH to 1.4 +/- 0.2 mU/L (P < 0.05 at 0100 h and P < 0.01 at 0200 h). According to the area under the curve analyses, the suppression in the nocturnal TSH was 32% in the 0.5 g/kg group and 45% in the 1.0 g/kg group (P < 0.05 for both cases). Circulating free or total T3 and T4 did not show any statistically significant changes that could explain the ethanol-induced inhibition in the nocturnal TSH peak. In protocol II, synthetic TRH (1 microgram/kg BW) was given intravenously, and blood samples were collected before, at 20 and 60 min. TRH significantly stimulated plasma TSH and PRL, but ethanol (1.0 g/kg BW) had no effect on these responses. In conclusion, small amounts of ethanol have unexpectedly great effects on nocturnal surges of TSH, and especially on those of GH, that are apparently mediated by suprapituitary mechanisms. On the other hand, ethanol did not affect the nocturnal PRL surge. These inhibitory effects of ethanol may have unfavorable effects on growth and metabolism in adolescent drinkers.

Adult↗