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.

Meta-analysis of the significance of asymptomatic bacteriuria in diabetes

OBJECTIVE

To evaluate whether asymptomatic bacteriuria (ASB) is more common in patients with diabetes than among control subjects. In addition, we wanted to clarify the clinical significance of ASB in patients with diabetes.

RESEARCH DESIGN AND METHODS

We conducted a systematic review and meta-analysis of published data since 1966. Twenty-two studies fulfilled the inclusion criteria of the meta-analysis.

RESULTS

ASB was present in 439 of 3,579 (12.2%) patients with diabetes and in 121 of 2,702 (4.5%) healthy control subjects. ASB was more common both in patients with type 1 diabetes (odds ratio 3.0 [95% CI 1.1-8.0]) and type 2 diabetes (3.2 [2.0-5.2]) than in control subjects. The point prevalence of ASB was higher in both women (14.2 vs. 5.1%; 2.6 [1.6-4.1]) and men (2.3 vs. 0.8%; 3.7 [1.3-10.2]) as well as in children and adolescents (12.9 vs. 2.7%; 5.4 [2.7-11.0]) with diabetes than in healthy control subjects. Albuminuria was more common in patients with diabetes and ASB than those without ASB (2.9 [1.7-4.8]). History of urinary tract infections was associated with ASB (1.6 [1.1-2.3]).

CONCLUSIONS

We were able to show that the prevalence of ASB is higher in all patients with diabetes compared with control subjects. We also found that diabetic subjects with ASB more often had albuminuria and symptomatic urinary tract infections.

Extended family history of diabetes and autoimmune diseases in children with and without type 1 diabetes

OBJECTIVE

To determine the extended family history of diabetes or autoimmune diseases in families with and without children having type 1 diabetes.

RESEARCH DESIGN AND METHODS

Three hundred case families and 381 control families were interviewed using structured questionnaires.

RESULTS

The proportion of case children having at least one relative with type 1 diabetes outside the nuclear family was higher than that of control children (50.3 vs. 31.8%, P < 0.001). The proportions of case and control children having relatives with type 2 diabetes or gestational diabetes were similar. Other autoimmune diseases occurred more frequently among the case children (9.7 vs. 1.1%, P < 0.001), in the case nuclear families (22.0 vs. 12.9%, P = 0.002) and in relatives outside the case nuclear family (72.0 vs. 62.2%, P = 0.007).

CONCLUSIONS

Type 1 diabetes and autoimmune diseases not only cluster in the nuclear families of children with type 1 diabetes but are also overrepresented in their extended families.

Adolescent manifestations of metabolic syndrome among children born to women with gestational diabetes in a general-population birth cohort

The association between maternal gestational diabetes (GDM) and manifestations of metabolic syndrome among Caucasian adolescents was studied with data from the population-based Northern Finland 1986 Birth Cohort. This is a longitudinal cohort study from early pregnancy until offspring age 16 years and includes data from a risk group-based GDM screen of pregnant mothers by an oral glucose tolerance test. Metabolic outcomes were compared between the offspring of women with GDM (OGDM; n = 95) and reference group offspring (n = 3,909). The prevalence of overweight was significantly higher in the OGDM group (18.8 vs. 8.4%; P < 0.001) than in the reference group. The median body mass index (20.8 vs. 20.2 kg/m(2), 95% confidence interval (CI) for the percentage difference adjusted for sex: 3.5%, 9.5%), waist circumference (73.3 vs. 71.5 cm, 95% CI: 3.2%, 7.5%), and fasting insulin (10.20 vs. 9.30 milliunits/L, 95% CI: 5.9%, 26.0%) were higher, and homeostatic model assessment-insulin sensitivity (74.7 vs. 82.3, 95% CI: -20.6%, -5.4%) was lower in the OGDM group. These differences were similar after an additional adjustment for birth weight and gestational age. The differences in waist circumference, insulin, and homeostatic model assessment-insulin sensitivity were attenuated but remained statistically significant after additional adjustment for body mass index at 16 years. These findings highlight the importance of prevention strategies among children born to women with GDM.

[Update on current care guidelines. Eating disorders in children and adolescents]

Eating disorders in childhood and adolescence are considered to involve both somatic and psychological problems. Treatment soon after diagnosis is aimed at correcting the nutritional and somatic status, including psychoeducative guidance and support for the patients and their family. Multi-professional cooperation is needed in the diagnosis and treatment of eating disorders. Once serious undernutrition is corrected, psychotherapy is indicated. Early and active treatment is associated with favourable prognosis.

Maternal type 1 and gestational diabetes: postnatal differences in insulin secretion in offspring at preschool age

BACKGROUND

It is well known that children born to mothers with diabetes in pregnancy are more likely to develop metabolic abnormalities in later life. Most prior studies have not differentiated between offspring of mothers with type 1 diabetes (T1DM) and gestational diabetes (GDM) or lack a control group of non-exposed offspring.

SUBJECTS

Offspring of T1DM (n = 16), GDM (n = 22) and mothers without diabetes (n = 25) born at Oulu University Hospital.

AIM

To assess insulin secretion and insulin resistance in the offspring of T1DM and GDM at preschool age in comparison with offspring of non-diabetic mothers.

METHODS

Anthropometric measurements and intravenous glucose tolerance testing were performed. First-phase insulin response (FPIR) and homoeostasis model assessment (HOMA) values were calculated. Pregnancy and birth data were analysed in relation to later metabolic parameters in all three groups using one-way analysis of variance (ANOVA) and analysis of covariance (ANCOVA).

RESULTS

At a mean age of 4.9 yr, offspring of T1DM had increased fasting serum insulin concentrations (p = 0.044), FPIR (p = 0.034) and HOMA-B values (p = 0.008) compared with offspring of GDM or with offspring of healthy controls (statistically non-significant). The GDM gained least weight during pregnancy, and when adjusted for maternal weight gain during pregnancy, there were no statistically significant differences between study groups.

CONCLUSIONS

Prenatal exposures to maternal type 1 and gestational diabetes may have different effects on postnatal glucose metabolism in the offspring assessed at a mean age close to 5 yr. Maternal weight gain in pregnancy may affect the postnatal glucose metabolism in the offspring.

Prevalence of metabolic syndrome at age 16 using the International Diabetes Federation paediatric definition

OBJECTIVE

We estimated the prevalence of metabolic syndrome (MS) in adolescents, using the new International Diabetes Federation (IDF) paediatric definition and compared this with prevalence estimated using the IDF adult definition and five other previously published definitions.

DESIGN

Cross-sectional survey in the prospective general population-based Northern Finland Birth Cohort 1986 (NFBC 1986) at age 16 years.

SETTING

Birth cohort in Finland.

PARTICIPANTS

5665 adolescents (2862 males and 2803 females) clinically examined in 2001-2002.

MAIN OUTCOME MEASURES

The prevalence of MS using different definitions.

RESULTS

The overall prevalence of MS using the IDF paediatric definition was 2.4% (95% CI 2.0 to 2.8%) at the age of 16 years. Using the IDF adult definition the overall prevalence was lower, 1.7% (CI 1.3 to 2.0%, European cut-offs for waist circumference) and 1.0% (CI 0.7 to 1.3%, North American cut-offs).

CONCLUSION

In 16-year-old adolescents, the paediatric IDF definition rendered a higher prevalence estimate than the adult definition.

Basal insulin switch from NPH to glargine in children and adolescents with type 1 diabetes

BACKGROUND

Insulin glargine is a long-acting insulin analogue increasingly used instead of neutral protamine Hagedorn (NPH) insulin in young subjects with type 1 diabetes.

OBJECTIVE

We evaluated the clinical course of diabetes in children and adolescents who were switched from NPH to insulin glargine.

METHODS

Between August 2003 and November 2004, a total of 76 subjects were switched to glargine in our clinic, treating 340 children with type 1 diabetes. All the subjects had been receiving insulin NPH, and their serum C-peptide levels had been non-detectable for at least 1 yr. Data were collected retrospectively, and 12-18 months after the change, experiences with glargine were inquired using a questionnaire. Seven subjects (9.2%) discontinued glargine before 12 months, and seven refused to participate.

RESULTS

Data for 62 subjects were analyzed. At the switch (0 months), their mean age was 12.7 yr (range 5.1-17.5), mean duration of diabetes was 6.7 yr (range 1.8-14.3), and mean hemoglobin A1c was (HbA1c) 9.2%. Twelve months later (+12 months), the mean HbA1c remained similar (9.2%), the proportion of long-acting insulin was smaller (47.7 vs. 58.1%; p < 0.001), and the daily insulin dose was lower (0.97 vs. 1.05 IU/kg; p < 0.001). The number of injections was lower at +12 months (17.7% with more than five injections vs. 64.5%; p < 0.001). No differences were seen in weight for height or the number of severe hypoglycemias. Most subjects who continued with glargine for > or =12 months considered glargine better than NPH.

CONCLUSIONS

A switch to insulin glargine retains a similar glycemic control and does not change the number of severe hypoglycemias.

Prevalence, segregation, and phenotype of the mitochondrial DNA 3243A>G mutation in children

OBJECTIVE

We studied the prevalence, segregation, and phenotype of the mitochondrial DNA 3243A>G mutation in children in a defined population in Northern Ostrobothnia, Finland.

METHODS

Children with diagnoses commonly associated with mitochondrial diseases were ascertained. Blood DNA from 522 selected children was analyzed for 3243A>G. Children with the mutation were clinically examined. Information on health history before the age of 18 years was collected from previously identified adult patients with 3243A>G. Mutation segregation analysis in buccal epithelial cells was performed in mothers with 3243A>G and their children whose samples were analyzed anonymously.

RESULTS

Eighteen children were found to harbor 3243A>G in a population of 97,609. A minimum estimate for the prevalence of 3243A>G was 18.4 in 100,000 (95% confidence interval, 10.9-29.1/100,000). Information on health in childhood was obtained from 37 adult patients with 3243A>G. The first clinical manifestations appearing in childhood were sensorineural hearing impairment, short stature or delayed maturation, migraine, learning difficulties, and exercise intolerance. Mutation analysis from 13 mothers with 3243A>G and their 41 children gave a segregation rate of 0.80. The mothers with heteroplasmy greater than 50% tended to have offspring with lower or equal heteroplasmy, whereas the opposite was true for mothers with heteroplasmy less than or equal to 50% (p = 0.0016).

INTERPRETATION

The prevalence of 3243A>G is relatively high in the pediatric population, but the morbidity in children is relatively low. The random genetic drift model may be inappropriate for the transmission of the 3243A>G mutation.

Noninvasive diagnosis of focal hyperinsulinism of infancy with [18F]-DOPA positron emission tomography

Congenital hyperinsulinism of infancy (CHI) is characterized by severe hypoglycemia due to dysregulated insulin secretion, associated with either focal or diffuse pathology of the endocrine pancreas. The focal condition is caused by a paternally inherited mutation in one of the genes encoding the subunits of the beta-cell ATP-sensitive potassium channel (SUR1/ABCC8 or Kir6.2/KCNJ11) and somatic loss of maternal 11p15 alleles within the affected area. Until now, preoperative diagnostics have relied on technically demanding and invasive catheterization techniques. We evaluated the utility of fluorine-18 l-3,4-dihydroxyphenylalanine ([(18)F]-DOPA) positron emission tomography (PET) to identify focal pancreatic lesions in 14 CHI patients, 11 of which carried mutations in the ABCC8 gene (age 1-42 months). To reduce bias in PET image interpretation, quantitative means for evaluation of pancreatic [(18)F]-DOPA uptake were established. Five patients had a visually apparent focal accumulation of [(18)F]-DOPA and standardized uptake value (SUV) >50% higher (mean 1.8-fold) than the maximum SUV of the unaffected part of the pancreas. When these patients were operated on, a focus of 4-5 x 5-8 mm matching with the PET scan was found, and all were normoglycemic after resection of the focus. The remaining nine patients had diffuse accumulation of [(18)F]-DOPA in the pancreas (SUV ratio <1.5). Diffuse histology was verified in four of these, and pancreatic catheterization was consistent with diffuse pathology in four cases. In conclusion, [(18)F]-DOPA PET is a promising noninvasive method for the identification and localization of the focal form of CHI.

Serum Androgen Levels and Testicular Structure during Pubertal Maturation in Male Subjects with Epilepsy

PURPOSE

To evaluate reproductive endocrine function in boys and young men with epilepsy taking an antiepileptic drug in a population-based, controlled study.

METHODS

Seventy patients and 70 controls matched for age and pubertal stage participated in this study. Twenty-eight patients were taking carbamazepine (CBZ); five, lamotrigine (LTG); 12, oxcarbazepine (OXC); and 25, valproate (VPA) as monotherapy for epilepsy. All subjects were examined clinically, and their medical histories were obtained. Serum reproductive hormone and sex hormone-binding globulin concentrations were measured, and testicular ultrasonography was performed.

RESULTS

Serum testosterone levels were within the normal range in young male patients with epilepsy. However, the patients taking VPA had high serum androstenedione levels at all pubertal stages. In prepuberty, their serum androstenedione values were already approximately fivefold compared with the values of the controls (8.7 nM; SD, 4.0 vs. 1.8 nM, SD, 1.0; p < 0.0003), and they were elevated in 64% of the VPA-treated patients compared with none of the other patients, p = 0.0006. Serum sex hormone-binding globulin levels were increased, and serum dehydroepiandrosterone sulfate concentrations decreased in the pubertal patients taking CBZ. The mean testicular volumes did not differ between the patients and the controls.

CONCLUSIONS

CBZ and VPA, but not LTG and OXC, are associated with changes in serum sex-hormone levels in boys and young men with epilepsy. However, the long-term health consequences of these reproductive endocrine changes during pubertal development remain to be established.

Insulin-regulated increase of soluble vascular adhesion protein-1 in diabetes

Vascular adhesion protein-1 (VAP-1) is one of the molecules on the endothelial cell membrane, which may guide inflammatory cells into atherosclerotic lesions. This dual function molecule may also contribute to the pathogenesis of atherosclerosis and other vasculopathies via its enzymatic activity that oxidizes primary amines to produce their corresponding aldehydes, hydrogen peroxide, and ammonium. Because VAP-1 also exists in a soluble form, we analyzed its potential usefulness as a biomarker to monitor and predict the extent of ongoing atherosclerotic processes. Soluble VAP-1 (sVAP-1) levels were determined from the sera of 136 Finnish men with established coronary heart disease and in 275 controls using sandwich enzyme immunoassays and correlated to multiple risk factors for coronary events. Intriguingly, sVAP-1 showed a statistically significant correlation with diabetes in both cohorts. We then collected patients with type 1 diabetes and observed that sVAP-1 levels were highly elevated when the patients were metabolically compromised. On normalization of their blood glucose and ketone body levels by exogenous insulin, their sVAP-1 concentration rapidly decreased to control levels. Intravenous glucose tolerance and hyperinsulinemic clamp tests further showed that elevation of blood glucose per se did not increase sVAP-1 levels, but rather, sVAP-1 was inversely correlated with circulating insulin concentrations. In conclusion insulin appears to regulate shedding or clearance of VAP-1, and an increase in sVAP-1 because of absolute or relative insulin deficiency may be directly involved in the pathogenesis of diabetic angiopathy.

Cardiovascular autonomic reactivity is decreased in adolescents with Type 1 diabetes

AIMS

To characterize autonomic nervous system function by means of the heart rate and blood pressure responses to various stimuli in relation to pubertal maturation in patients with Type 1 diabetes mellitus (DM).

METHODS

One hundred out of 138 eligible patients at the Out-patient Diabetes Clinic and 100 healthy control subjects were examined in terms of cardiovascular parameters at rest, during deep breathing and when standing. Heart rate variability was analysed with time domain,frequency domain and fractal dimension parameters. Tanner pubertal staging was performed before the examinations.

RESULTS

The time domain parameters of heart rate variability at rest or during standing did not significantly differ between the patients and controls in total or at pubertal stages. In the spectral analysis of heart rate variability the very low frequency band was decreased in the patients during standing (P = 0.023).The increase in the very low frequency (P = 0.013)and low frequency (P = 0.031) spectral powers upon changing from a supine position to standing was attenuated in the patients in total, while no significant differences were observed within the Tanner pubertal stages between patients and controls. Heart rate variability during deep breathing was decreased in the patients with distal polyneuropathy (P = 0.006).

CONCLUSIONS

Although cardiovascular integrity is in the main well preserved in adolescent patients with Type 1 DM, these patients are prone to attenuated autonomic nervous system reactivity.

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.

Lack of physiological suppression of circulating IGFBP-1 in puberty in patients with insulin-dependent diabetes mellitus

OBJECTIVE

To evaluate the interaction between serum free insulin, insulin-like binding protein (IGFBP)-1 and leptin concentrations during puberty in insulin-dependent diabetes mellitus (IDDM).

DESIGN

Adolescent patients with IDDM (n=101, age >9 years, duration >2 years) from the Outpatient Clinic of the Department of Pediatrics at Oulu University Hospital, and non-diabetic controls, were recruited to the study. Free insulin, IGFBP-1, leptin and insulin antibody concentrations were measured from a fasting serum sample.

RESULTS

Free insulin concentrations were lower in the patients than in the controls (4.3+/-2.3 mU/l compared with 6.5+/-3.1 mU/l, P<0.001), and there was an inverse correlation between free insulin and fasting blood glucose in the boys with diabetes (r=-0.53, P<0.001), whereas a positive correlation was observed between free insulin and leptin concentrations in the girls with diabetes (r=0.30, P=0.020). The IGFBP-1 concentrations were greater in the patients than in the controls (16.5+/-10.6 microg/l compared with 4.0+/-3.3, P<0.001), and they correlated significantly with blood glucose (r=0.63, P<0.001) and free insulin (r=-0.35, P<0.001). No significant difference was observed in the leptin concentrations between the patients and controls overall, despite greater total body fat in the girls with diabetes compared with the control girls.

CONCLUSIONS

Adolescents with IDDM are characterised by morning hypoinsulinaemia and high circulating IGFBP-1 concentrations, which may contribute to insulin resistance and impaired metabolic control during puberty. The mechanism behind the increased total body fat in the postpubertal female patients remains to be determined.

Genetic screening for maternal uniparental disomy of chromosome 7 in prenatal and postnatal growth retardation of unknown cause

OBJECTIVE

Many short-statured children lack an etiologic explanation for their retarded growth. Recently, uniparental disomy (UPD), the inheritance of both chromosomes of a chromosome pair from only 1 parent, has been associated with short stature for many chromosomes. Silver-Russell syndrome (SRS) represents an extreme syndrome of intrauterine growth retardation (IUGR) and slight dysmorphic signs, and maternal UPD of human chromosome 7 (matUPD7) has been observed in approximately 10% of SRS cases. In addition, matUPD7 has been reported in patients with only slight dysmorphic features and prenatal or postnatal growth retardation. The objectives of this study were to study the role of matUPD7 in growth failure of unknown cause and in cases of SRS, and to evaluate the efficiency of genetic testing for matUPD7 as a diagnostic tool.

METHODS

DNA samples were studied from 205 children, 92 girls and 113 boys, with short stature of unknown cause and their parents. The patient cohort included 39 cases of SRS, 91 patients with IUGR and subsequent postnatal short stature, and 75 patients with postnatal growth retardation only. MatUPD7 was screened for by genotyping DNA samples from the patient, mother, and father with 13 chromosome-7-specific polymorphic microsatellite markers.

RESULTS

Six (3%) of 205 matUPD7 cases were observed exclusively among 39 (15%) SRS patients studied. Patients with IUGR and/or postnatal growth retardation and with dysmorphic features did not reveal cases of matUPD7.

CONCLUSIONS

Our results indicate that matUPD7 cases are predominantly observed among patients meeting the criteria of SRS, and matUPD7 is not a common cause for growth retardation. Genetic screening for cases of matUPD7 among growth-retarded patients should be focused on patients with severe IUGR and features of SRS. In addition, matUPD7 screening is advisable in individuals with cystic fibrosis and other recessive disorders mapped to chromosome 7 who have unusually short stature.

Diabetes and elimination of antipyrine in man: an analysis of 298 patients classified by type of diabetes, age, sex, duration of disease and liver involvement

Effects of diabetes on hepatic drug metabolism in man has not yet been adequately clarified. Two hundred ninety-eight diabetic patients, classified by type of the disease, age, gender, duration of therapy and liver involvement, were investigated. The antipyrine plasma clearance rate and cytochrome P450 content determinations in liver biopsies of subjects with diagnostic liver biopsy were used as indices of hepatic drug metabolising capacity. Drug metabolism was reduced as a function of age. Antipyrine elimination rate was dependent on the type of diabetes (type 1 versus type 2) and gender. Untreated type 1 patients eliminated antipyrine rapidly and insulin treatment normalised antipyrine elimination (clearance rates 89.5 +/- 20.3 versus 58.8 +/- 17.2 ml/min.; P<0.001). Males aged 16-59 years, but not over 60, who responded insufficiently to insulin therapy, had a rapid antipyrine elimination, which could be normalised by readjustment of insulin administration. Women with insufficient glucose control on insulin therapy had antipyrine elimination rate comparable to controls. Among type 2 diabetic patients, women metabolised antipyrine normally, but men over 40 years of age showed a reduced antipyrine metabolism.

IN CONCLUSION

Drug metabolism in diabetes is affected by the type of disease, therapy and its effectiveness, and age and gender of the patients. These factors should be taken into account when evaluating overall drug metabolism in diabetic patients. This is especially important when investigating pharmacokinetics of new drugs for diabetic patients at different phases of the disease.

Leptin concentrations are elevated in newborn infants of diabetic mothers

BACKGROUND

Infants of diabetic mothers have been characterized by macrosomia due to hyperinsulinism. A relation has been observed between circulating levels of leptin and the intrauterine growth pattern.

METHODS

We studied the leptin and insulin concentrations in the cord blood of 29 newborn infants of mothers with type 1 diabetes (iT1DM), 70 newborn infants of mothers with gestational diabetes and 105 newborn infants of nondiabetic mothers.

RESULTS

There were significant differences (p < 0.001) between the 3 groups with the highest leptin levels 24.9 microg/l (range 1.7-94.1) in infants of mothers with iT1DM and the second-highest levels 14.0 microg/l (range 2.6-74.9) in infants of mothers with gestational diabetes (iGDM), whereas the control infants had the lowest leptin levels 10.0 microg/l (range 0.10-45.9). Girls had higher leptin concentrations than boys among the iT1DM and control infants. The insulin concentrations were 18.1 mU/l (range 1.9-123.3), 6.1 mU/l (range 1.1-51.4) and 3.6 mU/l (range 0.5-21.5) in the 3 groups (p < 0.001), respectively. A significant correlation was observed between leptin and insulin concentrations in iGDM and control infants (r = 0.51; p < 0.001 and r = 0.25; p < 0.05). Both absolute and relative birth weights correlated with leptin levels in all 3 groups (r = 0.60, p = 0.01 and r = 0.51, p = 0.05 in iT1DM; r = 0.51 and 0.56, p < 0.001 in iGDM and r = 0.42 and 0.59, p < 0.001 in control infants).

CONCLUSION

Our results confirm the relation between leptin concentrations and birth weight. They also suggest that leptin may be involved in the increased accumulation of adipose tissue characteristic of infants of diabetic mothers.

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.

Effect of an oral contraceptive preparation containing ethinylestradiol and gestodene on CYP3A4 activity as measured by midazolam 1'-hydroxylation

AIMS

To characterize the effect of an oral contraceptive (OC) containing ethinylestradiol and gestodene on the activity of CYP3A4 in vivo as measured by the 1'-hydroxylation of midazolam.

METHODS

In this randomised, double-blind, cross-over trial nine healthy female subjects received either a combined OC (30 microg ethinylestradiol and 75 microg gestodene) or placebo once daily for 10 days. On day 10, a single 7.5 mg dose of midazolam was given orally. Plasma concentrations of midazolam and 1'-hydroxymidazolam were determined up to 24 h and the effects of midazolam were measured with three psychomotor tests up to 8 h.

RESULTS

The combined OC increased the mean AUC of midazolam by 21% (95% CI 2% to 40%; P = 0.03) and decreased that of 1'-hydroxymidazolam by 25% (95% CI 10% to 41%; P = 0.01), compared with placebo. The metabolic ratio (AUC of 1'-hydroxymidazolam/AUC of midazolam) was 36% smaller (95% CI 19% to 53%; P = 0.01) in the OC phase than in the placebo phase. There were no significant differences in the Cmax, tmax, t(1/2) or effects of midazolam between the phases.

CONCLUSIONS

A combined OC preparation caused a modest reduction in the activity of CYP3A4, as measured by the 1'-hydroxylation of midazolam, and slightly increased the AUC of oral midazolam. This study suggests that, at the doses used, ethinylestradiol and gestodene have a relatively small effect on CYP3A4 activity in vivo.

Metabolic characteristics and urine albumin excretion rate in relation to pubertal maturation in Type 1 diabetes

BACKGROUND

The objective of this study was to assess the impact of pubertal maturation on urinary albumin excretion rate (AER) and persistent microalbuminuria, and to identify possible factors affecting urinary AER in adolescents with Type 1 diabetes.

METHODS

One hundred patients aged 9.1-19.0 years with a duration of diabetes of >2 years out of 138 eligible adolescents with Type 1 diabetes from an outpatient diabetes clinic participated in the study, together with 100 healthy controls. A timed overnight urine sample was collected in the hospital, where all the adolescents stayed for 22-24 h, and microalbuminuria was confirmed with at least one consecutive positive sample (AER 20-200 microg/min).

RESULTS

The prevalence of persistent microalbuminuria was 6%. All the patients affected were girls: one prepubertal (T I), one in late puberty (T IV) and three postpubertal (T V). These patients had significantly higher HbA(1c) levels than did the normoalbuminuric girls with Type 1 diabetes. Neither duration of diabetes nor age differed significantly between the two groups. AER increased more conspicuously with pubertal maturation in the boys with Type 1 diabetes than in the control boys, while the girls with diabetes had significantly higher body mass index (BMI) and serum total and LDL cholesterol than did the control girls. HbA(1c) was independently associated with AER in a multiple regression model. Diastolic blood pressure (BP) was elevated in both girls and boys with Type 1 diabetes as compared with healthy adolescents, while no difference was observed between the patients with microalbuminuria and normoalbuminuria.

CONCLUSIONS

Persistent microalbuminuria was mainly observed in late puberty and after puberty among adolescents with Type 1 diabetes. Female sex and poor metabolic control predispose such adolescents to this condition during pubertal maturation.

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.

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.

Reduced bone mineral density in long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

Osteoporosis and pathologic fractures are occasionally found in patients with childhood acute lymphoblastic leukemia (ALL). This study was performed to determine the degree of possible osteopenia in long-term survivors of childhood ALL.

PATIENTS AND METHODS

Lumbar spine (L2-L4) and femoral neck bone mineral densities (BMDs) (g/cm2) were measured in 29 survivors (aged 12 to 30 years, median 17) of childhood ALL 2 to 20 (median 8) years after discontinuation of chemotherapy. These results were compared with those from 273 healthy controls and expressed as a percentage of the age- and sex-matched control values (mean +/- standard deviation).

RESULTS

Lumbar and femoral BMDs were significantly reduced in survivors of childhood ALL. Particularly, male gender (lumbar: 91.7 +/- 10.4%, p = 0.008; femoral: 91.9 +/- 11.3%, p = 0.005) and a history of cranial irradiation (lumbar: 93.0 +/- 8.9%, p = 0.005; femoral: 94.4 +/- 13.3%, p = 0.03) were associated with low lumbar and femoral BMDs.

CONCLUSIONS

The detected deficit in bone density in survivors of childhood ALL may predispose these patients to osteoporotic fractures later in adulthood. A follow-up of BMD in survivors of childhood ALL should facilitate the identification of patients who would require specific therapeutic interventions to prevent further decrease of their skeletal mass and preserve their BMD.

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.

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.

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.

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.

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.

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.

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.

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)

Insulin-like growth factor binding protein production in human follicular thyroid carcinoma cells

IGFs and IGF binding proteins (IGFBPs) appear to serve as regulators of non-malignant thyroid cells from several species, but little is known about their role in thyroid malignancy. We have examined IGFBP production and hormonal regulation in two human thyroid follicular carcinoma cell lines; FTC-133 line derived from a local tumor recurrence and FTC-236 cells from a tumor metastasis. Under basal conditions these cell lines produced IGFBP-3, IGFBP-4 and IGFBP-2. In both cell lines, EGF or TPA stimulated IGFBP-3 production while TSH or forskolin inhibited IGFBP-3 production and reduced the stimulation of IGFBP-3 seen with EGF or TPA. IGFBP-4 production was increased in the presence of TSH, forskolin, and EGF and was reduced by TPA. mRNA assessment revealed that IGFBP-3 mRNA, more abundant in FTC-236 than FTC-133 cells, increased in the presence of EGF or TPA, while IGFBP-4 mRNA content was increased in the presence of TSH, EGF, and forskolin. These results indicate that IGFBP production in human thyroid follicular carcinoma clones is under specific hormonal regulation. IGFBP-3 production is increased by dedifferentiation factors such as EGF and TPA and inhibited by TSH and forskolin, which enhance differentiated function. The highly specific regulation of IGFBP-3 and IGFBP-4 suggests a potential role for these peptides in modulating malignant thyroid growth.

Normal stimulated growth hormone secretion but low peripheral levels of insulin-like growth factor I in prepubertal children with insulin-dependent diabetes mellitus

The hypothalamo-pituitary-insulin-like growth factor I (IGF-I) axis was studied in 24 prepubertal children with insulin-dependent diabetes mellitus (IDDM) and 12 non-diabetic children. There were no significant differences between the diabetic and control subjects in basal concentrations of immunoreactive growth hormone releasing hormone (ir-GHRH), growth hormone (GH) or stimulated GH levels, but after exercise ir-GHRH concentrations were higher in the diabetic children. Peripheral IGF-I levels were significantly lower in the diabetic children, and even lower in those with poor metabolic control. A positive correlation was found between IGF-I levels and circulating free insulin concentrations in the diabetic subjects (r = 0.49, p < 0.05). These observations suggest that the GH response to physiological stimulation is normal in prepubertal diabetic children. Exercise-induced GH response may not be mediated by GHRH. IGF-I levels were reduced in prepubertal children with IDDM and even more so in subjects with poor metabolic control. This may be a consequence of transitory hypoinsulineamia, emphasizing the importance of adequate insulinization to facilitate optimal growth in children and adolescents with IDDM.

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.

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)

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)

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.

Evaluation of growth hormone secretion and treatment

The secretion of growth hormone (GH) is regulated by a complex system that includes both neurotransmitters and feedback by hormonal and metabolic substrates. Over the last few years it has been recognized that GH release varies over a wide spectrum from deficient to excessive secretion. The diagnosis of GH deficiency is based on a combination of anthropometric and clinical signs on the one hand and an inadequate stimulated and/or spontaneous GH secretion on the other. There is no distinct boundary between deficient and sufficient GH secretion. The cut-off limit for normal GH release is accordingly relative and has increased over the past decade from 5 to 10 micrograms/l. The effect of GH therapy on growth can be evaluated only after treatment for at least 6 months. There is, therefore, an indisputable need for methods that would reflect growth response soon after the start of treatment. There are several promising biochemical candidates, e.g. the aminoterminal propeptide of type III procollagen, the carboxyterminal propeptide of procollagen I and the bone Gla-protein, which may turn out to be useful early indicators of the growth response to long-term GH therapy.

Accidental astemizole overdose in young children

6 cases of accidental astemizole poisoning in children have been reported to the Finnish Poison Information Center. The children were aged 1 year 7 months to 3 years 4 months and had taken doses of 2.5 to 16.7 mg/kg, at least twelve times that recommended. In 2 children the overdose was verified by measurement of drug concentrations. Despite measures to prevent drug absorption prolonged QTc-interval, a sign of cardiac toxicity, was found in all 5 children on whom an electrocardiogram was available for analysis, and severe ventricular arrhythmias developed in 1. Young children with accidental astemizole overdose should be carefully monitored in hospital. Similar precautions may be justified in cases of overdose with other selective H1-histamine receptor antagonists.

Pulsatile secretion of LH and FSH in prepubertal and early pubertal boys revealed by ultrasensitive time-resolved immunofluorometric assays

Pulsatile secretion of LH and FSH was examined in 10 prepubertal (aged 4.5-12.9 y) and seven early pubertal (aged 12.8-14.5 y) boys with ultrasensitive (0.019 and 0.014 IU/L) time-resolved immunofluorometric assays. Plasma LH and FSH levels were measured every 15 or 20 min for 6 h during the day and night. The lowest mean LH level in a prepubertal boy was 0.02 IU/L and in eight other prepubertal boys mean LH levels were less than 0.4 IU/L. In early pubertal boys the mean LH levels ranged from 0.3 to 6.5 IU/L. The difference in mean FSH level between prepubertal (0.61 IU/L) and early pubertal boys (1.85 IU/L) was smaller than the difference in LH level. All boys had significant LH and FSH pulses. The LH interpulse interval was 135 +/- 86 min (mean +/- SD) and 76 +/- 65 min for the prepubertal and pubertal boys, respectively (p less than 0.01). For FSH, the respective values were 150 +/- 122 and 221 +/- 157 min (p = NS). The mean LH pulse amplitudes were 11-fold greater in the early pubertal boys than in the prepubertal boys, whereas the mean FSH pulse amplitudes were similar between the two groups. The present method shows that the mean LH levels in prepubertal boys are much lower, and the increase during puberty larger, than previously reported. The increase is apparently due to increased pulse frequency and amplitude. The increase in mean FSH level is smaller and evidently not caused by an increase in pulse frequency or pulse amplitude.

Nocturnal release of immunoreactive growth hormone-releasing hormone and growth hormone in normal children

To evaluate the role of growth hormone-releasing hormone (GHRH) in the physiologic release of growth hormone (GH) we studied the nocturnal secretion of immunoreactive GHRH (ir-GHRH) and its relationship to GH release and various stages of sleep in six prepubertal (three boys) and six pubertal children (two boys) with normal stature. Their ages ranged from 8.1 to 14.9 yr and their bone ages from 6.8 to 14.8 yr. Blood was withdrawn continuously between 2200-0600 h at a constant rate of 5 mL/20 min. The EEG was simultaneously registered. The ir-GHRH and GH data were analyzed by a discrete-pulse detection algorithm (Pulsar). The number of nocturnal ir-GHRH pulses varied from 0-8 (median 7) and the number of GH peaks from 2-6 (median 3). Pubertal children had significantly more (p less than 0.05) ir-GHRH pulses and the pulse amplitude was higher (p less than 0.05) than in the prepubertal children. There were no significant differences in the GH parameters between the two groups. The ir-GHRH peaks were not significantly related to any specific sleep stage. The majority of the GH pulses (71%) were associated with slow wave sleep (p less than 0.001). Two-thirds (69%) of the GHRH peaks preceded closely or coincided with GH pulses (p less than 0.02). Pubertal subjects had more isolated ir-GHRH peaks than prepubertal children (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)