Peripheral nerve function is increasingly impaired during puberty in adolescents with type 1 diabetes.

OBJECTIVE: To evaluate the impact of puberty on peripheral nerve function in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS: Of 138 eligible patients with type 1 diabetes, 100 patients (age >9 years and diabetes duration >2 years) attending an outpatient diabetes clinic and 100 age- and sex-matched healthy control subjects took part in this cross-sectional study. Peripheral motor and sensory nerve conduction tests, cardiovascular reflex tests on the autonomic nervous system, and measurements of vibration-perception threshold (VPT) were performed. RESULTS: Nerve conduction velocity (NCV) in the distal motor and sensory nerves, the motor nerve distal latency, and the sensory nerve action potential (SNAP) amplitude were impaired in the adolescent patients with type 1 diabetes. The deterioration in motor NCV, H-reflex latency, and SNAP amplitude became more conspicuous in late puberty and postpuberty and was related to poor metabolic control. A total of 10 patients had distal diabetic polyneuropathy (DP) neurophysiologically, and these patients had significantly lower heart-rate variation in the deep breathing test than the other patients. Three of the patients with DP had peripheral neurological signs or symptoms. A slight difference in the VPT between the patients and control subjects was observed after puberty. CONCLUSIONS: Increasing subclinical motor nerve impairment can be detected during late puberty and after puberty, and sensory NCV and SNAP amplitude are reduced in adolescents with type 1 diabetes. Poor metabolic control during puberty appears to induce deteriorating peripheral neural function in young patients with type 1 diabetes.

Administration of growth hormone (GH), but not insulin-like growth factor-I (IGF-I), by continuous infusion can induce the formation of the 150-kilodalton IGF-binding protein-3 complex in GH-deficient rats.

In the adult circulation, 70-90% of the serum insulin-like growth factors (IGFs) are carried by IGF-binding protein-3 (IGFBP-3), which exists as part of a 150-kilodalton (kDa) ternary complex including IGF and an acid-labile subunit (ALS). We have examined the hormonal regulation and molecular distribution of IGFBP-3 in the circulation of a uniquely GH-deficient (GHD) rat model. For 7 days, GHD rats were given GH by either twice daily injections (1 mg/kg) or continuous infusion (2.4 mg/kg.day) or IGF-I by continuous infusion (1.4 mg/kg.day). Each day, weight and feed and water intake were monitored, and on day 7, liver, kidney, spleen, heart, and lung were weighted, and sera were collected. Serum IGF-I was analyzed by immunoassay, and the molecular distribution of the IGFBPs was determined by neutral size-exclusion chromatography combined with Western ligand blot and Western immunoblot. The GHD rats were 40-60% lighter than their normal littermates, and all organs examined were proportionately smaller. Serum IGF-I and IGFBP-3 levels were less than 10% of those in normal rats. Incubation of serum from GHD rats with [125I]IGF-II showed that radiolabel was incorporated only into a 44-kDa IGFBP region that contained the smaller IGFBPs. IGFBP-3 eluted around 60 kDa. No 150-kDa IGFBP region was detected. The administration of GH or IGF-I to GHD rats resulted in significant increases in weight gained, although food and water intake remained unaltered. Weight gain was observed in all three treatments groups. Both GH treatment regimens significantly increased liver, spleen, and lung weight, whereas IGF-I therapy increased spleen, kidney, and heart. Administration of GH twice daily did not increase serum IGF-I or IGFBP-3 concentrations, and the molecular distribution of IGFBP-3 remained unchanged. In contrast, continuous infusion of GH resulted in 5-fold increases in serum IGF-I and increases in IGFBP-3 levels. Size-exclusion chromatography combined with Western ligand blot analysis revealed that radioligand was incorporated into 150- and 60-kDa regions, and that IGFBP-3 was detectable in both regions. Thus, GH infusion was able to induce formation of the 150-kDa ternary complex by increasing circulating levels of IGF-I, IGFBP-3, and presumably ALS. Administration of IGF-I also increased serum IGF-I and IGFBP-3 levels, although the increase in IGFBP-3 was only in the 60-kDa region of the chromatograph, suggesting that IGF-I can induce neither ALS nor formation of the 150-kDa complex.(ABSTRACT TRUNCATED AT 400 WORDS)

Heat exposure elevates plasma immunoreactive growth hormone-releasing hormone levels in man.

The effects of heat exposure on plasma levels of GH and GHRH were studied in six younger (31-46 yr) and six older (49-66 yr) normal men. For the GHRH RIA, 2-mL plasma samples were purified on Sep-Pak C18 cartridges, from which the mean recovery of synthetic GHRH-(1-44) was 62 +/- 10% (+/- SD; n = 8). Heat exposure (15 min) in a Finnish sauna bath at an ambient temperature of 72 C, led to an increase in plasma GH levels from 2 to 5 micrograms/L (P less than 0.01) at 30 min in the younger men. Their rectal temperature had risen by 0.2 C at 15 min. Plasma immunoreactive GHRH increased from 9 to 36 ng/L (P less than 0.05) 5 min after heat exposure, and it gradually fell to the initial levels by 45 min. The older men did not have a significant increase in plasma GH or GHRH levels in response to the heat exposure. Reverse phase high pressure liquid chromatography studies of plasma immunoreactive GHRH suggested that the major circulating GHRH immunoreactivity was GHRH-(1-40). We conclude that heat exposure-stimulated GH release in young adult men is mediated by GHRH, but in older men, GHRH and GH responses do not occur.

Variable plasma growth hormone (GH)-releasing hormone and GH responses to clonidine, L-dopa, and insulin in normal men.

The effects of synthetic GHRH-(1-44) (1 microgram/kg, iv), clonidine (0.15 mg/m2, orally), L-dopa (0.5 g, orally), and insulin (0.1 IU/kg, iv) on plasma immunoreactive (ir) GHRH and GH levels were determined in normal men, aged 31-46 yr (n = 4-8). In addition, plasma ir-GHRH and GH concentrations were determined before and after the administration of clonidine in six younger men, aged 19-25 yr. GHRH was extracted from plasma using Sep-Pak C18 cartridges and measured with a mid-portion-specific GHRH antiserum. The mean plasma ir-GHRH and GH levels ranged from 9-11 ng/L and 0.5-1.5 microgram/L, respectively, in the older men during a 2-h control study. After GHRH administration, the mean plasma ir-GHRH concentration increased to a peak of 512.5 ng/L at 3 min and GH to a peak of 9.2 micrograms/L at 10 min. Clonidine resulted in a significant increase in mean plasma GH levels (P less than 0.05) in the younger men, but not in the older men. Plasma ir-GHRH concentrations did not change after clonidine. L-Dopa increased plasma ir-GHRH at 60 min (P less than 0.05) and GH at 60-120 min (P less than 0.05). Insulin-induced hypoglycemia increased plasma GH levels (to a mean of 23.8 micrograms/L at 60 min; P less than 0.001), whereas plasma ir-GHRH levels did not change. We conclude that the mechanisms of the various GH stimulation tests differ. Some GH responses, including those induced by insulin, do not appear to be mediated by GHRH.

Serum aminoterminal propeptide of type III procollagen: a potential predictor of the response to growth hormone therapy.

The circulating concentrations of insulin-like growth factor I (IGF-I) and immunoreactive aminoterminal propeptide of type III procollagen (PIIINP) were measured in 12 children with short stature (8 GH deficient and 4 non-GH deficient) before and after 1 week, 5 weeks, and 3, 6, and 12 months of treatment with biosynthetic hGH. Seven children had a growth response (increase in relative growth velocity greater than 1.5 SD during the initial 6 months) to GH therapy (responders), whereas 5 failed to respond (nonresponders). No relationship was found between the pretreatment plasma IGF-I levels or their changes during therapy and the growth response. Serum PIIINP levels increased considerably in all but 3 children, after as little as 1 week of GH administration. After 5 weeks, all responders had an increase in their serum PIIINP concentrations of 40% or more, whereas the nonresponders had less or no increments. There was a close correlation between the GH-induced increase in serum PIIINP levels at 5 weeks and growth velocity after 6 months of GH therapy (r = 0.77; P less than 0.01). The correlation was even stronger with the growth velocity at 12 months (r = 0.83; P less than 0.001). The serum PIIINP response to short-term GH administration could be an early predictor of the growth response to long-term GH therapy. In contrast to plasma IGF-I, the PIIINP response may be useful both in GH deficient and non-GH deficient children.

Long-term survivors of childhood cancer have an increased risk of manifesting the metabolic syndrome.

Survivors of childhood cancer have been reported to have a severalfold increased risk of death from cardiovascular disease. A cluster of metabolic abnormalities, including obesity, insulin resistance, hyperinsulinemia, glucose intolerance, hypertension, and dyslipidemia, have been designated as forming a metabolic syndrome that is associated with increased cardiovascular mortality. We studied 50 survivors (23 males) of childhood cancer, aged 10.5-31.2 yr, an average of 12.6 yr (range, 7.9-21.3 yr) after their diagnosis and compared them with 50 age- and sex-matched controls for signs of the metabolic syndrome by examining clinical and anthropometric measures, serum lipid profile, and fasting plasma insulin and glucose concentrations. Spontaneous nocturnal GH secretion was also evaluated in the cancer survivors. The patients had increased relative weight (P = 0.03) and body fat mass (P < 0.001), decreased serum high density lipoprotein (HDL) cholesterol (P < 0.001), and a reduced ratio of HDL to total cholesterol (P = 0.01). Fasting plasma glucose and insulin levels were higher (P < 0.001 and P = 0.003, respectively) in the cancer survivors than in the controls. The patients had an increased risk [odds ratio (OR), 4.5; 95% confidence interval (CI), 1.3-15.8; P = 0.01] of obesity (relative weight, > 120%), fasting hyperinsulinemia ( > 111 pmol/L; OR, 3.0; 95% CI, 1.0-8.6; P = 0.04), and reduced HDL cholesterol ( < 1.07 mmol/L; OR, 7.9; 95% CI, 2.2 to 29.6; P < 0.001). A combination of obesity, hyperinsulinemia, and low HDL cholesterol was seen in eight cancer survivors (16%), but in none of the controls (P = 0.01). This high risk group was characterized by reduced spontaneous GH secretion (P = 0.02). Long term survivors of childhood cancer appear to have an increased risk of manifestations of the metabolic syndrome. Decreased GH secretion may contribute to these metabolic abnormalities.

Pituitary size assessed with magnetic resonance imaging as a measure of growth hormone secretion in long term survivors of childhood cancer.

We investigated 37 long term survivors of childhood cancer to study the relationship among growth, GH secretion, and pituitary size. The median follow-up time after diagnosis was 13.2 yr. The pituitary gland was visualized with magnetic resonance imaging. Radiated patients (n = 25) had a reduced relative height and showed a greater reduction in relative height after diagnosis than nonradiated patients (n = 12). The patients had lower spontaneous nocturnal GH secretion than controls due to a reduced peak amplitude. Spontaneous GH secretion was lower in radiated patients than in nonradiated subjects. The patients had lower plasma insulin-like growth factor-I (IGF-I) and serum IGF-binding protein-3 (IGFBP-3) concentrations than the controls. Radiated subjects had decreased IGF-I and IGFBP-3 concentrations compared to nonradiated subjects. Half of the patients (20 of 37) evaluated with magnetic resonance imaging had a reduced pituitary size (pituitary height, < -2 SD score). Radiated subjects had smaller pituitary glands than nonradiated ones. Seventeen of 20 patients (85%) with reduced pituitary size had decreased nocturnal GH release. There was a positive correlation between nocturnal GH secretion, plasma IGF-I, and serum IGFBP-3 levels, on the one hand, and pituitary height, on the other. These results indicate that cranial radiation may result in tissue damage, leading to decreased pituitary size, reduced spontaneous GH secretion, and impaired linear growth. The finding of reduced IGF-I levels in both radiated and nonradiated patients combined with decreased IGFBP-3 concentrations in radiated patients, indicates that cytotoxic chemotherapy may induce hepatic damage resulting in decreased IGF-I synthesis.

Urinary insulin-like growth factors (IGF) and IGF-binding proteins in normal subjects, growth hormone deficiency, and renal disease.

Recent studies in our laboratories have shown that urine from healthy adults contains immunoreactive and intact insulin-like growth factor-binding protein-3 (IGFBP-3). The aim of this study was to assess urinary IGF-I, IGF-II, and IGFBP-3 in a cross-sectional study of healthy subjects, as well as characterize urinary IGFBPs (uIGFBps) in patients with GH deficiency (GHD) and renal disease, such as, Alport syndrome, immunoglobulin A nephropathy, focal segmental glomerulosclerosis, and systemic lupus erythematosus. Urinary concentrations of IGF-I and IGF-II in pooled spot morning urines of healthy subjects, measured by RIA, were low and relatively unaltered throughout age, when expressed as either nanograms per milliliter or nanograms per milligram creatinine. To determine the complement of IGFBPs in urine of healthy subjects, spot morning urine samples were subjected to Western ligand blot and immunoblot analysis. IGFBP-3 was detected at 40-50 kDa, possibly due to variable glycosylation of uIGFBP-3. In addition, a 32-kDa IGFBP-2 and smaller unclassified IGFBPs were detected. Unlike uIGFs, urinary concentrations of IGFBP-3 (uIGFBP-3; nanograms per milligram creatinine) were age-, but not sex-related. Levels of uIGFBP-3 ranged from 40-60 ng/mL in children between 4 and 10 yr of age. After 11 yr, immunoreactive uIGFBP-3 progressively declined, attaining a plateau after 26 yr of age to approximately 18 ng/mg creatinine. uIGFBP-3 did not correlate with uIGF levels. Regulation of IGFBP-3 in the urine of normal subjects and of renal disorders was examined by RIA, Western ligand blot (WLB), and protease assay. Intact uIGFBP-3 was consistently found in normal urine and little urinary protease was identified. In GHD patients, IGFBP-3 by WLB was low or undetectable, whereas RIA levels of uIGFBP-3 were normal or high, consistent with the presence of IGFBP-3 proteolytic activity. In Alport syndrome, both RIA measures and WLB analysis were high, as was the IGFBP-3 proteolytic activity. Patients with immunoglobulin A nephropathy, focal segmental glomerulosclerosis and systemic lupus erythematosus measured low-normal levels of IGFBP-3 by WLB and RIA, and displayed little protease activity. This study provides normative data concerning radioimmunoassayable levels of IGFBP-3 in urine. The presence of normal-elevated levels of uIGFBP-3 by RIA in GHD indicates that uIGFBP-3 levels are not under GH control and are unlikely to represent filtered serum IGFBP-3.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute insulin response tests for the differential diagnosis of congenital hyperinsulinism.

Mutations in genes encoding the two subunits of the beta-cell ATP-sensitive potassium channel (K(ATP)) channel (SUR1 and Kir6.2) are the major cause of congenital hyperinsulinism (CHI). In this study, the K(ATP) channel genes were screened in a population-based study that included all verified Finnish CHI patients (n = 43) in a 27-yr period. Seven different mutations were identified, which accounted for 60% of all cases. The functional consequences of the major missense mutations were studied in vivo by determining acute (1-3 min) plasma insulin and C-peptide responses to calcium (n = 18), glucose (n = 12), and tolbutamide (n = 11) in those CHI patients who were able to take part in these studies. C-peptide and insulin responses to calcium were significantly higher in the patients with SUR1-E1506K mutation, compared with patients without K(ATP) channel mutations. The patients with SUR1-V187D mutation showed a reduced response to tolbutamide but unexpectedly did not show any response to calcium stimulation. A compound heterozygous patient with Kir6.2-(-54)/K67N mutations responded to calcium but also to tolbutamide. In conclusion, our results show that a positive response in the calcium test is indicative of a K(ATP) channel mutation, but all mutations cannot be identified with this method. The insulin response to tolbutamide in patients with SUR1 mutations is impaired to different extents, depending on the genotype. The combination of calcium and tolbutamide tests is a useful tool for the detection of CHI patients with K(ATP) channel dysfunction. Our results, however, also demonstrate the complexity of these responses and the difficulties in their interpretation.

Plasma tacrine concentrations are significantly increased by concomitant hormone replacement therapy.

BACKGROUND: In vitro results suggest that the synthetic hormones used in postmenopausal hormone replacement therapy (HRT) may be significant inhibitors of oxidative drug metabolism. Moreover, HRT has been reported to enhance response to tacrine in postmenopausal patients with Alzheimer's disease, but the mechanism of this interaction remains unclear. OBJECTIVE: To examine the effect of HRT with 2 mg estradiol valerate and 0.25 mg levonorgestrel once daily on the pharmacokinetics of tacrine. METHODS: Ten healthy female volunteers received treatment for 10 days with once-daily HRT or placebo in a randomized, double-blind crossover study. One hour after the last HRT or placebo capsule on day 10, the subjects received a single 40-mg dose of tacrine. Plasma samples were collected for 30 hours and urine samples were collected for 24 hours after tacrine intake for the measurement of tacrine and 1-hydroxytacrine concentrations. RESULTS: HRT increased the mean plasma concentration-time curve calculated from zero to infinity (AUC) of tacrine by 60% (P = .009); the greatest individual increase in the AUC was about threefold. Similarly, the mean peak concentration in plasma of tacrine was 46% (P = .031) higher in the HRT phase compared with the placebo phase. HRT reduced the mean apparent oral clearance of tacrine by 31% (P = .014), but no significant difference was found in the elimination half-life or the renal clearance of tacrine between the HRT phase and the placebo phase. The metabolic ratio (1-hydroxytacrine AUC/tacrine AUC) was significantly (mean, 26%; P < .001) reduced in all 10 subjects. CONCLUSIONS: HRT with estradiol and levonorgestrel significantly increased plasma tacrine concentrations. This interaction between tacrine and HRT involves reduced metabolic conversion of tacrine to its main metabolite 1-hydroxytacrine by CYP1A2 during the first-pass phase. The interaction may be clinically important with regard to both enhanced efficacy and increased likelihood of concentration-dependent adverse effects of tacrine in the long-term treatment of patients with Alzheimer's disease. Accordingly, smaller doses of tacrine may be appropriate when coadministered with HRT.

Pregnancy in growth hormone-deficient rats: assessment of insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs) and IGFBP protease activity.

Pregnancy in rodents is associated with important maternal metabolic changes. Early pregnancy is considered to be an anabolic phase of nutrient storing, while in late pregnancy, a catabolic phase develops to help meet the metabolic demands of the rapidly growing conceptus. Similarly, major changes also occur in the IGFs, IGF-binding proteins (IGFBPs) and GH axis. In the rat, maternal serum IGF-I levels increase from early to mid-pregnancy, after which IGF-I levels decline. Conversely, as IGF-I levels decline, pituitary-derived rat GH increases twofold. This coincides with a decrease in IGFBP-3 and the appearance of an IGFBP protease. However, the physiological role of these changes is unclear. The aim of our study was to examine the roles of GH, IGFs and IGFBPs during pregnancy in a unique isolated GH-deficient rat model, spontaneous dwarf rats. Pregnancy in GH-deficient dams resulted in a significantly reduced litter number, and maternal weight gain (day 21-day 1) was reduced by 28% when compared with dams with normal GH levels (GH-normal dams). In the sera of GH-normal dams, IGF-I levels increased 2.6-fold by day 4 of pregnancy and then progressively declined to below non-pregnant levels. Serum IGF-II levels were low and remained unchanged. Western-ligand blot analysis showed that IGFBP-3 was present in non-pregnancy and early pregnancy sera, but declined dramatically after day 12. This decline in IGFBP-3 coincided with the detection of an IGFBP protease. In contrast, in non-pregnancy sera from GH-deficient rats, serum IGF-I concentrations were 10% of the levels seen in GH-normal females, and neither IGF-I nor IGF-II concentrations changed with pregnancy. Furthermore, in GH-deficient dams, serum IGFBP-3 (as assessed by Western-ligand blot analysis) was low in non-pregnancy and early pregnancy sera, and became undetectable by day 12 of pregnancy. The low concentrations of IGFBP-3 in early pregnancy serum from GH-deficient rats coincided with IGFBP-proteolytic activity, and the decline in serum IGFBP-3 after day 16 was the result of increased protease activity. In conclusion, isolated GH deficiency results in: (1) reduced maternal weight gain and correspondingly smaller litter sizes; (2) low and unchanged maternal serum IGF-I levels; (3) low, but declining, serum IGFBP-3 levels; and (4) activity of IGFBP protease(s) detectable in early and late pregnancy, which may modulate the bioavailability and bioactivity of IGFs by regulating IGFBP-3.

Insulin-like growth factor binding proteins in prepubertal children with insulin-dependent diabetes mellitus.

To study the possible role of insulin-like growth factor binding proteins (IGFBPs) in the discrepancy between normal or only slightly retarded growth and substantially reduced concentrations of insulin-like growth factor I (IGF-I) in prepubertal children with insulin-dependent diabetes mellitus (IDDM), we measured the plasma concentrations of IGF-I, IGFBP-1, IGFBP-2 and IGFBP-3 and free insulin in 24 prepubertal diabetic subjects and 12 control children. In addition, the growth hormone response to exercise was evaluated. The diabetic children had significantly decreased peripheral IGF-I levels (8.2 + 1.1 (SEM) vs 16.7 + 2.5 nmol/l; p < 0.001), whereas the concentrations of free insulin were increased (217 + 14 vs 103 + 21 pmol/l; p < 0.001). The concentrations of IGFBP-1 and IGFBP-3 were of the same magnitude in both groups. The diabetic children had significantly increased levels of IGFBP-2 (465 + 13 vs 416 + 14 micrograms/l; p = 0.029), which were inversely related to the circulating IGF-I levels (r = -0.35; p = 0.034). The diabetic and control children had comparable growth hormone responses to exercise. Diabetic children with poor glucose control had even lower IGF-I levels than those with moderate metabolic control (6.0 + 0.8 vs 10.3 + 1.7 nmol/l; p = 0.037). No differences could be observed in the plasma concentrations of various IGFBPs between these two groups of diabetic subjects. The absence in prepubertal diabetic children of increased IGFBP-1 levels observed in adolescent and adult patients with IDDM may contribute to their maintained linear growth, despite definitely decreased IGF-I concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Collagen metabolites in the prediction of response to GH therapy in short children.

To evaluate the role of collagen metabolites in the prediction of the response to GH treatment we measured the serum concentrations of the C-terminal propeptide of type I procollagen (PICP) and the N-terminal propeptide of type III procollagen (PIIINP) with specific RIAs in 35 short children (16 boys) before and after 5 days, 5 weeks and 3 months of GH therapy. The mean age of the children was 10.3 years (range 1.9-16.4 years) and the bone age ranged from 1.2 to 12.5 years (mean 7.6 years). The initial mean relative height (RH) was -3.6 SDS (range -6.6 to -2.4 S.D.). Nineteen children were found to have GH deficiency (GHD; peak GH responses in two pharmacological tests < 10 micrograms/l), while the remaining 16 were considered to have undefined short stature (USS). The children were treated with recombinant human GH (0.1 U/kg given subcutaneously at bedtime 6-7 times/week). The increases in RHI over the first 6 and 12 months of therapy were used as response measures. There was already a significant increase (P < 0.001) in both the serum PICP and PIIINP levels at 5 days, and the concentrations continued to rise up to 3 months, PICP levels rising less than the PIIINP levels. In the whole group the RHI over 6 months correlated most strongly with the absolute PICP concentrations at 3 months (rS = 0.59; P < 0.05), while the absolute PIIINP concentrations at 3 months showed the strongest relation to the one year RHI (rS = 0.69; P < 0.001). In the GHD group the 6 month RHI was most strongly related to the absolute PICP concentration at 3 months (rS = 0.59; P < 0.05). In the USS group the absolute PICP concentrations at 3 months correlated most strongly with the one year RHI (rS = 0.82; P < 0.01). Significant correlations were also observed between the absolute PIIINP levels at 3 months and the 6 month RHI (rS = 0.60; P < 0.05) and 12 month RHI (rS = 0.76; P < 0.01) in this group. These results show that GH therapy results in an unequivocal increase in circulating concentrations of PICP and PIIINP. The serum PICP and PIIINP concentrations may be of value in the prediction of the long-term response to GH therapy.

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.

Impaired androgen production in female adolescents and young adults after total body irradiation prior to BMT in childhood.

Pubertal development and androgen production were evaluated 1-10 years after bone marrow transplantation (BMT) in 15 females aged 14-23 (mean 17) years. Before BMT, these patients had received combination chemotherapy for hematologic malignancy, and all had had a transplant program including total body irradiation (TBI). Of the nine patients who were pre-menarcheal at BMT, two had subsequently experienced spontaneous menarche at 11.5 and 13.3 years of age. Six were post-menarcheal, but became amenorrheic after BMT. Menstruation subsequently started spontaneously in one of them 6 years after BMT. At the time of the study, three patients were early to mid-pubertal and 12 late pubertal or post-pubertal. Twelve patients were receiving sex steroid substitution therapy. Serum concentrations of testosterone, androstenedione, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) were determined. Androgen levels of late pubertal and post-pubertal transplanted patients were compared with 19 post-menarcheal patients aged 14-21 (mean 17) years who had been treated for hematologic malignancy with conventional chemotherapy. Testosterone levels of 52 healthy post-menarcheal females aged 14-29 (mean 19) years were measured as controls. Androgen levels of the BMT patients were lower than those of the conventionally treated patients. Differences in testosterone, androstenedione and DHEA levels were significant. Three spontaneously menstruating BMT patients had normal androgen levels. Testosterone levels of the conventionally treated patients and healthy controls were similar. Subnormal androgen production might be one factor behind the problems in pubertal development and sex life experienced by females after BMT. The use of these hormone levels for follow-up purposes and the potential value of androgen replacement therapy in females after TBI merit further study.

Growth in children with poor-risk neuroblastoma after regimens with or without total body irradiation in preparation for autologous bone marrow transplantation.

Impaired growth after TBI prior to BMT has been a constant finding in children with leukemia. The growth of poor-risk neuroblastoma (NBL) survivors treated with myeloablative preparative regimens and ABMT at the Hospital for Children and Adolescents, University of Helsinki, since 1982 is reported. Two separate groups were analyzed: (1) The TBI- patients (n = 15) were conditioned with high-dose chemotherapy only. They had been treated at the age of 1.0-6.3 (mean 3.0) years and the post-ABMT follow-up time was 1.5-14.5 (mean 7.7) years. (2) The TBI+ patients (n = 16) had received TBI in addition to high-dose chemotherapy. They had been treated at the age of 1.3-4. 8 (mean 3.0) years, and the post-ABMT follow-up time was 1.5-8.0 (mean 4.7) years. The height standard deviation score (SDS) was similar for the two groups at the time of diagnosis, -0.3 +/- 1.2 (mean +/- s.d.), and at the time of ABMT, -0.7 +/- 1.1. After transplantation, the height SDS continued to decrease in the TBI+ group, the mean being -2.0 SDS at 5 years after ABMT. In the TBI-group, the mean height SDS remained within -0.7 to -0.9 to the 10 years of follow-up. Five patients received growth hormone (GH) therapy starting 2-6 years after ABMT. They all had low GH secretion in provocative tests. All showed some response to GH therapy. The mean height SDS increased 0.4 SDS during the 3 years following the start of GH therapy, while in the untreated patients a decrease of 0. 8 SDS during the corresponding time (P = 0.009) was observed. We conclude that NBL patients grow poorly following ABMT when TBI is included in the conditioning regimen, but close to normally when treated without TBI. The need for GH therapy should be evaluated early to avoid an unnecessary decrease in final height.

Regulation of human granulosa-luteal cell progesterone production and proliferation by gonadotropins and growth factors.

The effects of human chorionic gonadotropin (hCG), follicle-stimulating hormone (FSH), fibroblast growth factor (FGF), and epidermal growth factor (EGF) on human granulosa-luteal cell proliferation and progesterone (P) production were studied in vitro. The cells were obtained from an in vitro fertilization protocol and were cultured for 2 to 12 days on plastic culture dishes or on dishes coated with extracellular matrix (ECM). During the first 2 to 4 days of culture, basal P production was high and could not be further stimulated with gonadotropins. Thereafter, basal P production decreased and could be stimulated by both hCG and FSH. The cells growing on ECM produced less P than the cells growing on plastic. EGF and FGF significantly increased cell proliferation on both substrates. FGF did not influence P production, while EGF clearly increased basal P production of the cells cultured on plastic. The high P production in cultured human granulosa cells obtained from follicles stimulated in vivo indicates that at least some of the cells were luteinized. The present data also demonstrate that EGF and FGF are mitogenic for human granulosa-luteal cells, and EGF regulates their biosynthesis in vitro. These results suggest that growth factors may also regulate granulosa cell function in vivo.

A comparison of different definitions of growth response in short prepubertal children treated with growth hormone.

BACKGROUND: How to define poor growth response in the management of short growth hormone (GH)-treated children is controversial. AIM: Assess various criteria of poor response. SUBJECTS AND METHODS: Short GH-treated prepubertal children [n = 456; height (Ht) SD score (SDS) ≤-2] with idiopathic GH deficiency (IGHD, n = 173), idiopathic short stature (ISS, n = 37), small for gestational age (SGA, n = 54), organic GHD (OGHD, n = 40), Turner syndrome (TS, n = 43), skeletal dysplasia (n = 15), other diseases (n = 46) or syndromes (n = 48) were evaluated in this retrospective multicenter study. Median age at GH start was 6.3 years and Ht SDS -3.2. RESULTS: Median [25-75 percentile] first-year gain in Ht SDS was 0.65 (0.40-0.90) and height velocity (HtV) 8.67 (7.51-9.90) cm/year. Almost 50% of IGHD children fulfilled at least one criterion for poor responders. In 28% of IGHD children, Ht SDS gain was <0.5 and they had lower increases in median IGF-I SDS than those with Ht SDS >0.5. Only IGHD patients with peak stimulated growth hormone level <3 µg/l responded better than those with ISS. A higher proportion of children with TS, skeletal dysplasia or born SGA had Ht SDS gain <0.5. CONCLUSION: Many children respond poorly to GH therapy. Recommendations defining a criterion may help in managing short stature patients.

Management of polycystic ovary syndrome in childhood and adolescence.

INTRODUCTION: Polycystic ovary syndrome (PCOS) is a common endocrinopathy in women. It may manifest as early as in the first decade of life. Most often it becomes clinically apparent during adolescence with maturation of the hypothalamic-pituitary-ovarian axis. CLINICAL FEATURES: Typical features in adolescence include irregular menstrual cycles, acne, hirsutism, obesity and signs of insulin resistance such as acanthosis nigricans. Biochemical hyperandrogenism and polycystic ovaries are often present. However, some adolescents have no evidence of clinical and biochemical hyperandrogenism despite dysfunctional polycystic ovaries. PATHOGENESIS: The pathogenesis of PCOS is uncertain, however, both genetic and environmental factors play a role, resulting in key features of the syndrome; disordered gonadotropin release, dysregulated steroidogenesis, ovarian and adrenal hyperandrogenism and hyperinsulinism. PCOS is often accompanied by metabolic syndrome, with abnormalities in lipid and glucose metabolism. TREATMENT: Treatment of PCOS is symptomatic. Lifestyle changes are a first-line intervention, however, increasing evidence suggests that metformin and estrogen-progestin combination pill may be beneficial. CONCLUSIONS: PCOS is a lifelong condition that carries long-term health risks. Several risk factors for PCOS have been identified and clinicians should be alert for this condition already in childhood and adolescence. Early intervention and counseling might be the key for prevention of co-morbidities of PCOS.