Growth hormone therapy of Turner's syndrome: beneficial effect on adult height

OBJECTIVE

To carry out a multicenter, prospective, randomized trial of human growth hormone (GH), alone or in combination with oxandrolone (OX), in patients with Turner's syndrome (TS).

METHODS

In an initial phase lasting 12 to 24 months, 70 girls with TS, verified by karyotype, were randomly assigned to one of four groups: (1) observation, (2) OX, (3) GH, or (4) GH plus OX. After completion of the first phase, group 3 subjects continued to receive GH only. All other subjects were treated with GH plus OX. Subjects were followed up until attainment of adult height and/or cessation of treatment. Data from this trial were compared with growth characteristics of 25 American historical subjects with TS (matched for age, height, parental target height, and karyotype) who never received either GH or androgens.

RESULTS

Of the 70 subjects enrolled, 60 completed the clinical trial. The 17 subjects receiving GH alone all completed the trial and reached a height of 150.4+/-5.5 cm (mean +/- SD), 8.4+/-4.5 cm taller than their mean projected adult height at enrollment (95% confidence interval [CI]: 6.3 to 10.6 cm). The 43 subjects receiving GH plus OX attained a mean height of 152.1+/-5.9 cm, 10.3+/-4.7 cm taller than their mean projected adult height (95% CI: 8.9 to 11.7 cm). The historical control subjects had a mean adult height of 144.2+/-6.0 cm, precisely matching their original projected adult height of 144.2+/-6.1 cm.

CONCLUSIONS

GH, either alone or in combination with OX, is capable of stimulating short-term growth and augmenting adult height in girls with TS. With early diagnosis and initiation of treatment, an adult height of more than 150 cm is a reasonable goal for most girls with TS.

Five years experience with recombinant human growth hormone treatment of children with chronic renal failure

11 males, aged 2.5-16.3 years (6.8 +/- 4.1) with growth retardation (Standard Deviation Score--SDS > -2.00) consequent to chronic renal failure (CRF) received recombinant human growth hormone (rhGH) for 18 to 60 mo (40.9 +/- 15.4). Growth velocity (GV) increased from 5.4 +/- 2.2 for the year prior to rhGH to 8.9 +/- 1.6 (p = 0.00001), 7.4 +/- 1.7 (p < 0.03), 7.6 +/- 1.6 (p < 0.006), 6.5 +/- 1.0 (p < 0.05) and 7.5 +/- 1.3 (p = NS) cm/yr following 12, 24, 36, 48 and 60 mo respectively of treatment. The mean SDS for height decreased from -3.21 at baseline to -0.85 at 60 mo (p = 0.0004); 7 of 8 pts treated for > 36 mo had a SDS more positive than -2.00; 3 reached the 50th percentile on the growth curve. In 2 patients the dosage was doubled to achieve the increase in GV; in one patient it took 5 yrs to reach a SDS more positive than -2.00. A significant increase in weight gain and mid-arm muscle circumference over baseline values were indicative of the anabolic effect of rhGH. The mean increase in bone age was similar to the increase in chronologic age; the delta bone age-delta height age was not significant indicating no loss of growth potential following rhGH. Although 3 patients required the initiation of dialysis following rhGH treatment, the mean calculated creatinine clearance did not decrease significantly. No significant adverse effects were noted. These data indicate that long-term rhGH treatment is effective in improving the GV of children with CRF and facilitating catch-up growth without loss of growth potential.

Factors predicting the response to growth hormone (GH) therapy in prepubertal children with GH deficiency

To identify factors influencing the response to GH therapy, we used a multiple regression model to analyze data from 632 naive prepubertal children with GH deficiency (GHD). There were 523 children with idiopathic and 109 children with organic GHD. They were treated with the same preparation of biosynthetic methionyl GH (somatrem, Protropin) for at least 1 yr. In children with idiopathic GHD, six variables predicted 40% of the response to treatment. They were (listed in relative importance, all P < 0.0001): age, log maximum GH, weight adjusted for height, dosing schedule, dose, and midparental height. Three variables, pretreatment growth rate, log maximum GH, and age, predicted 20% of the GH response in children with organic GHD. When data for all children were analyzed using analysis of covariance, children with idiopathic GHD grew better than those with organic GHD (mean +/- SD, 9.2 +/- 2.4 vs. 8.8 +/- 2.6 cm/yr; P < 0.0001). The children (both organic and idiopathic GHD) who did not respond well to treatment were younger and thinner than those who did. Early diagnosis and initiation of therapy should be beneficial to ultimate height attainment. The best response to GH therapy should be in young children with severe idiopathic GHD who receive daily weight-adjusted doses. The use of GH daily in higher doses would be expected to be most beneficial in older children with acquired and/or less severe GHD or in children who are underweight for height.

Conventional and nonconventional uses of growth hormone

Although GH has been available as a therapeutic agent for the GH-deficient child for more than 30 years, the conditions of its use have yet to be optimized. The availability of biosynthetic material has provided researchers with the opportunity to develop the protocols necessary to begin to finally answer the most fundamental questions pertaining to dose, frequency, and duration of treatment. It has also permitted the initiation of prospective trials in a large number of conditions that result in childhood short stature, with the expectation that some or many of them will be treated effectively and safely. Finally, it has opened the door to an entire spectrum of potentially new uses of GH and other growth factors for so-called nonconventional indications. That these have implications that range from the short-term rapid healing of a burn graft site, to the more efficient induction of ovulation, to the long-term preservation of lean body mass has excited the interest of investigators in many fields of medicine and physiology. Thus, the recent progress reported in this paper is really the beginning of the new research that will take place with GH and growth factors.

Six-year results of a randomized, prospective trial of human growth hormone and oxandrolone in Turner syndrome

Seventy girls with Turner syndrome, verified by karyotype, were randomly assigned to observation or treatment with human growth hormone (hGH), oxandrolone, or a combination of hGH plus oxandrolone for a period of 12 to 24 months, to assess the effect of treatment on growth velocity and adult height. Subsequently, all subjects received either hGH alone or hGH plus oxandrolone. Data are presented for 62 subjects treated for a period of 3 to 6 years. When compared with the anticipated growth rate in untreated patients, the growth rate after treatment with hGH, both alone and in combination with oxandrolone, showed a sustained increase for at least 6 years. Treatment is continuing in over half of the subjects; at present, 14 (82%) of 17 girls receiving hGH alone and 41 (91%) of 45 girls receiving combination therapy exceeded their expected adult heights. Thirty girls have completed treatment; mean height for these 30 patients is 151.9 cm, compared with their mean original projected adult height of 143.8 cm. We conclude that therapy with hGH, alone and in combination with oxandrolone, can result in a sustained increase in growth rate and a significant increase in adult height for most prepubertal girls with Turner syndrome.

Pediatric germ cell and human chorionic gonadotropin-producing tumors. Clinical and laboratory features

Germ cell tumors may cause various aberrations in pubertal development. In prepubertal boys, these tumors may secrete human chorionic gonadotropin, resulting in precocious puberty. Human chorionic gonadotropin and alpha-fetoprotein are both useful as germ cell tumor markers in the diagnosis and detection of recurrence. Pregnancy-specific beta 1-glycoprotein, another oncoplacental antigen, has been used as a tumor marker for trophoblastic neoplasms, but not previously for human chorionic gonadotropin-producing tumors associated with precocious puberty. Patients with germ cell tumors may also have abnormal karyotypes. Herein, we describe six male pediatric patients with germ cell tumors and pubertal derangements seen during an 8-year period. We confirm the high incidence of associated sexual precocity, the usefulness of alpha-fetoprotein, human chorionic gonadotropin, and pregnancy-specific beta 1-glycoprotein as tumor markers in the diagnosis and follow-up of these patients, and the occurrence of sex chromosomal abnormalities.

Recombinant human growth hormone treatment of children with chronic renal failure: long-term (1- to 3-year) outcome

Treatment of nine boys, aged 2.8-16.3 years, with growth retardation consequent to chronic renal failure (CRF), with recombinant human growth hormone (rhGH) for 12-36 months demonstrated a significant improvement in growth velocity at each 12-month interval compared with that achieved the year prior to treatment. Despite the acceleration in growth velocity the bone age did not increase more than the increase in chronological age during the period of treatment. The mean calculated creatinine clearance did not decrease significantly during the 36 months of treatment; however, two patients required institution of dialysis at 18 and 30 months following the initiation of rhGH treatment. There was no exacerbation of the glucose intolerance of uremia following rhGH treatment. Currently, six of seven patients who have been treated for more than 24 months have achieved sufficient acceleration of growth velocity to attain a standard deviation score that was more positive than -2.00, and are above the 5th per centile for chronological age on the growth curve. These data indicate that rhGH treatment of growth-retarded children with CRF results in accelerated growth velocity during the 2nd and 3rd years of treatment, and demonstrate the potential for such children to achieve normal stature for chronological age despite the continued presence of renal failure.

Growth hormone mediates the growth of T-lymphoblast cell lines via locally generated insulin-like growth factor-I

It has become evident that locally produced insulin-like growth factors-I and -II (IGF-I and IGF-II) play an important role in the medication of GH action upon tissues. To explore this concept with respect to immunocompetent cells, we analyzed IGF production and clonogenic responsiveness of immortalized human T-cell lines established from seven normal controls and four Laron dwarfs. While the normal T-cell lines showed significant augmentation of basal colony formation in response to both IGF-I and GH, little increase in clonogenesis in response to GH was seen with the Laron T-cell lines. Assay of basal and GH-stimulated conditioned media demonstrated low, but measurable, levels of IGF-I and IGF-II from both normal and Laron T-cells. Under serum-free incubation conditions, GH stimulation of normal T-cell lines failed to generate significant increases in mean IGF-I or IGF-II concentration and no increase in the mean IGF-II concentration in conditioned medium were observed after GH stimulation of Laron T-cell lines. Nevertheless, the increased cloning efficiency of the normal T-cell lines in response to either GH or IGF-I was nearly completely abrogated by preincubation of cells with antibodies to either IGF-I or the type I IGF receptor. These studies, thus, support a role for locally generated IGF-I in the mediation of GH action on T-lymphocytes and indicate that this effect is mediated via the type I IGF receptor.

Growth hormone treatment in the United States: demographic and diagnostic features of 2331 children

Demographic, diagnostic, and baseline clinical data were collected for a large cohort (N = 2331) of children who started treatment with biosynthetic human growth hormone (GH) between October 1985 and October 1987. Eighty-one percent met classic criteria for GH deficiency and were classified as having idiopathic GH deficiency (59%), organic GH deficiency (18%), or septo-optic dysplasia (4%). The remaining 19.8% had short stature of varied causes. Height standard deviation score at diagnosis, maximum GH response to stimulation, and heights of parents were examined according to gender, race, age at diagnosis, and previous treatment history. The predominance of boys in all subgroups except septooptic dysplasia, and the observation that girls with idiopathic GH deficiency were comparatively shorter than boys at diagnosis, suggest ascertainment bias. Black children with idiopathic GH deficiency were shorter than white children at diagnosis, and their low overall representation (6.0%) compared with their percentage in the at-risk population (12.9%) also suggest ascertainment bias among races. These data provide a profile of GH deficiency as it is currently defined and expose possible inherent biases in the diagnostic process. Now that GH supply is no longer limited, criteria for its use should be formulated to avoid apparent underascertainment or late diagnosis of GH deficiency in girls and black children.

T-lymphoblast cell lines from Laron dwarfs augment basal colony formation in response to extremely high concentrations of growth hormone

The clinical entity of Laron dwarfism is characterized by resistance to both endogenous and exogenous GH and may be due to a deficiency or absence of functional GH receptors. We previously showed that two types of hematopoietic cells derived from these patients are resistant to the in vitro growth-promoting action of GH at concentrations below 500 micrograms/L. In the current study we found that Laron T-cell lines had a mean peak augmentation of basal colony formation of 22 +/- 3.4% above baseline in response to a GH concentration of 10,000 micrograms/L. Since cloned cDNAs for human and rabbit GH receptors and rat PRL receptors show a high degree of sequence homology, we undertook studies of PRL action in cells from patients with Laron dwarfism to determine if the Laron defect was also associated with PRL unresponsiveness. Quantitating the augmentation of colony formation by T-lymphoblast cell lines established from three Laron dwarfs, we found normal responsiveness to PRL at concentrations of 25-10,000 micrograms/L. It is, thus, possible that the responsiveness of Laron T-cell lines to very high concentrations of GH could be mediated through an intact PRL (or other lactogenic) receptor based on the known affinity of GH for these receptors in other systems. These data suggest that cells from patients with Laron dwarfism have normal in vitro responsiveness to PRL and that the defect in Laron dwarfism appears to be specific to the GH receptor-effector pathway. It remains to be determined whether intact alternative lactogenic receptor mechanisms subserve any clinical effects of GH in patients with Laron dwarfism.

Absence of nonclassical congenital adrenal hyperplasia in patients with precocious adrenarche

We studied 31 patients (28 girls and 3 boys), ranging in age from 3.2-7.9 yr, with precocious adrenarche defined by the presence of early sexual hair development, no signs of virilization, and bone age within +3 SD of the mean for chronological age. To determine if this symptom complex stemmed from any form of nonclassical (late-onset) congenital adrenal hyperplasia, an ACTH stimulation test was performed on each patient using a standard 0.25-mg dose of Cortrosyn, given as an iv bolus. Twelve pubertal children (7 girls and 5 boys) and 18 prepubertal children (11 girls and 7 boys) served as normal controls. Baseline and stimulated 17-hydroxypregnenolone (17-OHPreg), 17-hydroxyprogesterone, (17-OHP), 11-deoxycortisol, dehydroepiandrosterone, androstenedione, testosterone, and cortisol levels were measured. Using published nomogram standards for serum 17-OHP response to ACTH, no child with precocious adrenarche was diagnosed as having nonclassical 21-hydroxylase deficiency. Eight girls, however, had a stimulated 17-OHP value that exceeded the mean response for pubertal and prepubertal controls by more than +2 SD [range, 295-670 ng/dL (8.94-20.3 nmol/L)]. Stimulated 11-deoxycortisol values [less than 400 ng/dL (11.6 nmol/L)] ruled out any cases of nonclassical 11 beta-hydroxylase deficiency. No patient had nonclassical 3 beta-hydroxysteroid dehydrogenase deficiency, as defined by both the stimulated 17-OHPreg and the 17-OHPreg/17-OHP ratio to be more than +2 SD above the mean for pubertal children [1354 ng/dL (41.0 nmol/L) and 10.4, respectively]. In conclusion, we could not provide any biochemical evidence for nonclassical congenital adrenal hyperplasia in a large group of children with precocious adrenarche.

Accelerated growth after recombinant human growth hormone treatment of children with chronic renal failure

We studied the effect of recombinant human growth hormone treatment on five boys, aged 4.6 +/- 1.8 years, who had chronic renal failure secondary to congenital renal diseases (mean creatinine clearance (+/- SD): 18.3 +/- 6.3 ml/min/1.73 m2 (0.32 +/- 0.11 ml/sec/1.73 m2]. Patients received 0.125 mg/kg of growth hormone three times per week for 1 year. Before beginning treatment, the children had a mean annual growth velocity of 4.9 +/- 1.4 cm/yr (range 3.0 to 6.3 cm/yr), with a mean standard deviation score for a height of -2.98 +/- 0.73 (range -2.16 to -3.59). At the end of therapy, the mean growth velocity had increased to 8.9 +/- 1.2 cm/yr (range 7.5 to 10.7 cm/yr), and the mean height standard deviation score improved to -2.36 +/- 0.83 (range -1.15 to -3.18). Bone age advancement was consistent with the period of growth. Routine laboratory determinations, including results of glucose tolerance testing, did not vary significantly from pretreatment levels. These preliminary data indicate that growth-retarded children with chronic renal failure can respond to exogenous growth hormone therapy with a marked acceleration in growth velocity.

Leprechaunism: in vitro insulin action despite genetic insulin resistance

We recently identified a female leprechaun infant with marked hyperinsulinemia [as high as 10,975 microU/ml (78,746 pmol/liter)], presumably secondary to insulin resistance. She had two physical findings suggestive of possible insulin action: cystic ovarian enlargement with gonadotropin-independent steroid secretion and persistent, severe myocardial hypertrophy. To examine the pathophysiology of this disorder we measured the in vitro sensitivity to insulin and other growth factors of erythroid progenitors and a T-lymphoblast cell line derived from her peripheral blood. Resistance to insulin was demonstrated by failure of her circulating erythroid progenitor cells to augment proliferation in response to physiologic concentrations of insulin (1-10 ng/ml). An immortalized T lymphoblast cell line was established by transforming the cells with the human retrovirus human T cell leukemia virus II. This cell line showed little or no response to physiologic concentrations of insulin contrary to consistently observed stimulation of colony formation by cell lines similarly derived from normals. The patient's T lymphoblasts, however, showed normal sensitivity to insulin-like growth factor I. In response to supraphysiologic insulin concentrations (25-1000 ng/ml), leprechaun T lymphoblasts showed significant augmentation of colony formation (peak 189% above baseline at 50 ng/ml); normal T lymphoblasts also showed responsiveness at these high insulin concentrations. Preincubation with a monoclonal antibody against the insulin-like growth factor I receptor (alpha IR-3 at 5000 ng/ml) blocked the in vitro effect of physiologic concentrations of insulin-like growth factor and supraphysiologic concentrations of insulin on leprechaun and control T lymphoblast colony formation, but had no clear effect upon the response to physiologic insulin concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperthyroidism in children treated with long term medical therapy: twenty-five percent remission every two years

We use an antithyroid drug for the treatment of hyperthyroidism due to Graves' disease in children and adolescents for as long as the patients are willing to comply and/or tolerate the drug. In more than 60 patients treated since 1961, the remission rate was 25% in the first 2 yr. This report looks at these same patients again, followed for an additional 5 yr. Survival analysis methods applied to the follow-up data on 63 children confirm our original statistical findings and suggest a continuing remission rate of 25% every 2.1 +/- 0.4 (+/- SE) yr regardless of the duration of previous therapy. The median time to remission was 4.3 +/- 1.5 yr, and 75% of patients are predicted to be in remission in 10.9 +/- 2.3 yr. Of 36 patients who went into remission, defined by their being euthyroid for 1 yr after cessation of therapy, 1 relapsed, and 2 developed spontaneous hypothyroidism; the remainder are euthyroid 1-11.7 yr after therapy was discontinued. Of 14 who switched from medical therapy, 2 of 7 treated surgically and 4 of 7 treated with 131I are hypothyroid. Only 1 patient had a significant adverse reaction to both methimazole and propylthiouracil. While medical therapy may have some direct effect on the autoimmune response in hyperthyroidism, its role in affecting the time to ultimate remission is unknown. These data, however, describe the course of children so treated and allow us to present therapeutic options initially or during treatment based on statistically derived probabilities of outcome.

Tissues of the Laron dwarf are sensitive to insulin-like growth factor I but not to growth hormone

Tissues from patients with Laron dwarfism are resistant to the actions of endogenous or exogenous GH. As a result, insulin-like growth factor I (IGF-I) levels are low, possibly contributing to the severe growth deficiency that occurs in patients with this syndrome. In this study, we found that erythroid progenitor cells and permanently transformed T-cell lines from two patients with Laron dwarfism responded in vitro to added IGF-I in concentrations ranging between 1-10 ng/mL despite no stimulatory response to added GH in concentrations of up to 500 ng/mL. Normal or near-normal responsiveness to insulin was also demonstrated. The persistence of GH resistance in the cultured T-cell lines confirms the primary genetic nature of the defect in Laron dwarfism. The preservation of in vitro growth responsiveness to IGF-I in hematopoietic tissue from the Laron dwarfs suggests that affected individuals are sensitive to this factor and may respond to it in vivo.

The role of immunotherapy in type I diabetes mellitus

Type I diabetes mellitus appears to result from an insidious immunologic destruction of pancreatic beta-cells in genetically susceptible persons exposed to one or a series of environmental insults. This genetic susceptibility is related to alleles located on the sixth chromosome in the HLA-DR or an adjacent region. With superimposition of a viral or other environmental triggering event, cell-and antibody-mediated events are activated that lead to the specific autorejection of beta-cells and consequent insulin deficiency. Immunosuppressive strategies to impede or halt complete destruction of beta-cells, using cyclosporine, have already been initiated in both animals and humans with diabetes mellitus. Because of the potential toxicity of all current immunosuppressive regimens, such therapies cannot, at this time, be considered for wide-scale use in persons with type I diabetes. Reported inductions, however, of insulin independence in patients with newly diagnosed type I diabetes using cyclosporine or other agents underscore the role of the immune system in the pathogenesis of the disease and highlight the need to develop safer, more specific immunomodulation designed to avoid complete beta-cell destruction.

Aortic dilation, dissection, and rupture in patients with Turner syndrome

We report two patients with Turner syndrome who had aortic dissection and rupture, one with prior repair of coarctation. We also note the high incidence (8.8%) of unrecognized aortic root dilation in a group of 57 patients with Turner syndrome whom we prospectively evaluated by echocardiography. Our analysis and review of previously reported cases suggests that multiple risk factors may exist for aortic dissection, including coarctation, bicuspid aortic valve, and systemic hypertension, but that these need not be present. Aortic root dilation may be an additional finding that suggests the patient with Turner syndrome is also at risk. When it is present, magnetic resonance imaging visualizes the entire aorta and allows quantification of the site and degree of dilation. In patients with dissection, the aorta often exhibits pathologic evidence of cystic medial necrosis similar to the finding in patients with Marfan syndrome. Therapeutic methods to decrease risk, such as those directed toward prevention of bacterial endocarditis, blood pressure control, and perhaps prophylactic beta blockade or surgical reconstruction, may need to be considered. Patients with Turner syndrome, their families, and the physicians who care for them should be aware of the significance of unexplained chest pain, dyspnea, or hypotension as potential manifestations of aortic dissection or rupture.

Growth without growth hormone: evidence for a potent circulating human growth factor

A potent growth factor was detected in the serum of a child with growth hormone (GH) deficiency and early growth delay whose growth velocity spontaneously increased to supranormal levels despite persistent GH deficiency by both radioimmunoassay (RIA) and radioreceptor assay. Thyroid function, prolactin, insulin response to oral glucose, glucose response to intravenous insulin, and computerised tomography of the head were all normal. Whilst somatomedin-C levels measured by RIA were low or low-normal, in vitro somatomedin bioactivity measured by bioassay was normal, suggesting the presence of a growth factor other than somatomedin-C. By way of confirmation, the patient's serum was incubated with erythroid progenitor cells from peripheral blood of a normal individual and a Laron dwarf. In this system, proliferation of normal erythroid progenitors was almost double that obtained with physiological concentrations of GH or control sera, and Laron erythroid progenitors, which were completely resistant to added GH, also responded strongly to the patient's serum. The patient's growth is therefore independent of GH and other known growth factors.

Insulin resistance in total lipodystrophy: evidence for a pre-receptor defect in insulin action

The cause of insulin resistance in lipodystrophic diabetes is unknown but has generally been ascribed to dysfunction at either the receptor or post receptor level. In a 14 year-old girl with total acquired lipodystrophy, subcutaneous and intravenous insulin requirements approximated 600 units daily. However, circulating total and free insulin levels were not increased, and during testing by the euglycemic clamp method, the glucose response to increasing free insulin concentrations was within the range found in eight subjects with insulin-dependent diabetes. Insulin clearance during the euglycemic clamp was 43, 98, 115, and 116 mL/kg/min at each of four insulin infusion rates compared to means of 13, 13, 12, and 11 in the control subjects with diabetes. No detectable degrading activity was present in serum, and serum inhibited insulin degradation normally. Binding of insulin to IgG, IgM, and IgE was not increased, insulin binding to monocytes and erythrocytes was not sufficiently abnormal to account for the the insulin resistance, and insulin receptor increased insulin clearance or accelerated degradation of insulin by tissues.

Diminished in vitro responsiveness of circulating erythroid progenitor cells to insulin as an indicator of insulin resistance

While insulin resistance is considered characteristic of extreme obesity, it may be more difficult to demonstrate in less severe forms of obesity. We studied five moderately obese individuals [mean body mass index (MBMI), 34.1 +/- 1.85 (+/- SE) kg/m2], one massively obese patient (BMI, 50.2 kg/m2), and seven age-matched normal subjects (MBMI, 22.4 +/- 0.93 kg/m2). While two of the obese patients had normal glucose tolerance, all had fasting hyperinsulinemia (P less than 0.02 vs. normal subjects) and exaggerated insulin responses after oral glucose challenge, as defined by area under the 3-h insulin response curve (P less than 0.01 vs. normal subjects). That this hyperinsulinemia represented in vivo insulin resistance was supported by the glucose and insulin responses in four individuals to an iv glucose bolus analyzed by the minimal modeling technique. Study of monocyte insulin receptors revealed no reduction in total insulin binding in the four obese patients tested. Since physiological concentrations of insulin stimulate the in vitro growth of normal human erythroid progenitor cells (EPC), we reasoned that this response might be blunted in cells from individuals with endogenous insulin resistance. The mean peak EPC proliferative response (26.7 +/- 9.11% above baseline) in the obese hyperinsulinemic group was significantly less than the corresponding mean value in the control group (92.6 +/- 5.24% above baseline, P less than 0.001). These results suggest that the minimal modeling technique is a sensitive method for the in vivo demonstration of insulin resistance in moderately obese individuals and that EPC responsiveness to physiological concentrations of insulin reflects in vivo insulin sensitivity and may be used as an in vitro indicator of insulin resistance.

Carbohydrate tolerance in cystic fibrosis is closely linked to pancreatic exocrine function

We evaluated carbohydrate tolerance in nine thin cystic fibrosis (CF) patients and in six controls, measuring responsiveness to the following insulinotropic secretagogues: oral glucose, IV glucose, and IV tolbutamide. Glucose responses segregated patients into two groups: Group I with normal carbohydrate tolerance associated with normal to slightly increased insulin responses, and Group II with impaired carbohydrate tolerance associated with insulinopenia. This latter group included one patient with frank diabetes. The CF patients demonstrated a significant positive correlation between insulin secretion, in response to each secretagogue, and pancreatic exocrine function as measured by serum pancreatic amylase isoenzyme concentration. Pancreatic alpha-cell function, as reflected by basal plasma glucagon concentrations, also correlated well with exocrine function in the CF patients, excluding the diabetic individual. The enteroinsular axis of the CF group was intact as reflected by normal plasma gastric inhibitory polypeptide concentrations in Group I and by elevated levels, basally and in response to oral glucose, in the insulinopenic Group II patients. Furthermore, those patients with impaired tolerance demonstrated a greater magnitude of insulinopenia compared to controls following IV glucose and possibly IV tolbutamide, than following oral glucose. Thus, these data suggest that loss of carbohydrate tolerance in patients with CF, like that seen with classical chronic pancreatitis, 1) parallels the loss of exocrine function, 2) is associated with appropriate enteroinsular signaling, and 3) can be detected earlier or more easily following testing with direct IV secretagogues than following oral glucose stimulation.

Insulin resistance in a young man with cystic fibrosis

An 18-year-old man had cystic fibrosis (CF) and insulin-resistant carbohydrate intolerance characterized by (1) obesity, basal hyperinsulinemia, and hyperglucagonemia; (2) impaired oral glucose tolerance; (3) hyperinsulinemia in response to oral and intravenous (IV) administration of glucose and to IV administration of tolbutamide; (4) exaggerated gastric inhibitory polypeptide secretion following orally administered glucose; and (5) diminished sensitivity to insulin administered IV compared with other patients with CF. Both parents also demonstrate basal and stimulated hyperinsulinemia in response to orally administered glucose. The long-term outlook for patients with CF is improving, and more patients are surviving childhood. Thus, it should be recognized that an insulin-resistant form of carbohydrate intolerance may develop in patients with CF with obesity and/or genetic risk factors.

Precocious puberty and chronic renal failure

A 7 1/2-year-old boy with chronic renal failure (CRF) experienced transient central isosexual precocious puberty. Simultaneously, he demonstrated hyperprolactinemia with galactorrhea and apparent secondary or tertiary hypothyroidism. These findings could have been a consequence of an unexplained hypothalamic dysregulation. During this period, marked linear growth ensued (8.7 cm during nine months) associated with rapid bone age advancement (four years during a 21-month period). Whereas most boys with CRF demonstrate delayed pubertal development and suppressed linear growth, our patient's transient condition demonstrated that both growth and puberty can occur in the presence of uremia.

Self-monitoring of blood glucose levels and intensified insulin therapy. Acceptability and efficacy in childhood diabetes

Prospective studies have shown that children and adolescents with diabetes have a high prevalence of serious complications and a sharp reduction in life expectancy. Recently, self-monitoring of blood glucose levels has become available and, for the first time, provides a method for determining the concentration of blood glucose with considerable accuracy. We have introduced this method of control assessment to our pediatric diabetic patient population in conjunction with a program of intensified insulin administration (two or more injections per day). This is a report of the ready acceptance of these methods by children and adolescents and their parents (53/63, or 84%). The effectiveness of this program is evidenced by a progressive and significant reduction in the percentage of glycosylated hemoglobin during a period of 18 months in a majority of the subjects. These observations suggest that improved glycemic control can be achieved in young diabetics by using multiple insulin injections and self-monitoring of blood glucose levels. Whether such control can lead to a better long-term outlook for diabetics remains to be seen.

Early-morning hyperglycemia in diabetic individuals treated with continuous subcutaneous insulin infusion

Significantly early-morning hyperglycemia was observed in insulin-dependent diabetic individuals who were otherwise well controlled while receiving a continuous subcutaneous insulin infusion (CSII) at standard doses. We measured the levels of the five key counterregulatory hormones (CRH) throughout the night for a total of 10 patient-nights in four such patients. No abnormalities in the patterns of glucagon, cortisol, growth hormone, epinephrine, or norepinephrine secretion were observed. Stepping up the daytime basal infusion rate in six affected patients before bedtime by 37.0 +/- 7.5% and maintaining the increased infusion until breakfast significantly blunted this early-morning hyperglycemia without causing significant early nighttime hypoglycemia. Plasma glucose concentrations before breakfast averaged 106.8 +/- 13.0 mg/dl after increase of the overnight basal infusion rate as compared with 269.8 +/- 39.1 mg/dl while receiving a single basal rate over 24 h (P less than 0.02). Thus, the "dawn phenomenon" may occur in patients receiving CSII by an unmodified algorithm and may be obviated by a carefully determined step-up in nocturnal basal infusion rate. The mechanism responsible for this phenomenon of increased early-morning insulin need remains to be elucidate.

Echocardiography reveals a high incidence of bicuspid aortic valve in Turner syndrome

The most common cardiac defect in Turner syndrome has been described previously as coarctation of the aorta. We have evaluated 35 consecutive patients with Turner syndrome by clinical examination and by M-mode and two-dimensional echocardiography. Twelve patients (34%) had isolated, nonstenotic bicuspid aortic valve. A high correlation (82%) existed between the presence of a systolic ejection click and echocardiographic evidence of a bicuspid aortic valve. These data indicate that bicuspid aortic valve may be the most common cardiac anomaly in Turner syndrome.

The use of theophylline as an in vivo probe of adrenocortical function

The first step in the stimulatory action of most polypeptide hormones, including ACTH, is interaction with a specific target organ plasma membrane receptor. Theophylline, a nonspecific stimulus of several endocrine processes, does so presumably by circumventing the receptor step and directly increasing cAMP by inhibiting phosphodiesterase-mediated hydrolysis. Five patients with adrenal insufficiency, documented by a lack of cortisol secretion in response to exogenous ACTH, underwent a 4-h iv infusion of theophylline. In three of the five individuals, a significant concentration of cortisol was measured in serum for the first time. The patients who responded included one patient with the syndrome of ACTH insensitivity, one with ACTH deficiency, and one with idiopathic primary adrenal failure. Two patients with autoimmune adrenalitis failed to respond to theophylline, although one was tested very early in the course of her disease. We also noted that theophylline stimulated renin secretion and, in one patient with an intact zona glomerulosa, evoked a secondary rise in aldosterone equal to that produced by diuresis and upright posture. These studies suggest that the preservation of cortisol responsiveness to theophylline, after the loss of sensitivity to ACTH, may be relate to either the duration of the adrenal insufficiency or to the etiological mechanism. Patients with autoimmune adrenalitis may undergo more rapid and complete adrenocortical destruction, therapy losing sensitivity to both ACTH and theophylline, whereas patients with insufficient or ineffective ACTH stimulation may have receptor failure before the loss of intracellular function. Thus, responsiveness to iv theophylline may serve not only as a probe of potential adrenocortical reserve, but also as an indicator of pathogenesis.

Prepubertal gynecomastia caused by an adrenal tumor. Diagnostic value of ultrasonography

Prepubertal gynecomastia is a rare disorder that may be associated with adrenal or testicular tumors. An adrenal tumor causing a mixed feminizing-virilizing syndrome in a 6-year-old boy was identified by ultrasonography, whereas excretory urography failed to show any abnormality. Highly elevated estrone concentrations were found in the plasma, as were more modestly increased levels of estradiol, testosterone, androstenedione, and 11-deoxycortisol. After removal of the tumor, all hormonal concentrations returned to normal prepubertal levels.

Diabetes mellitus

Diabetes mellitus is classified into two major categories: type I, which is insulin dependent, and type II, which is not. Insulin resistance in type II diabetes may be related to impaired receptor binding in some forms of the disorder. In the past, diabetes in pregnant women resulted in high rates of maternal and infant mortality. During the past 10 years, however, better management of maternal diabetes has led to a significant sharp reduction in maternal and fetal morbidity and mortality. The long-term outcome of insulin-dependent diabetes remains gloomy, probably because adequate control of the disease has rarely been achieved. Recently, more stringent efforts have been made to achieve tighter control. Frequent monitoring of blood glucose levels at home and use of constant infusion insulin pumps may help to achieve this end until successful islet transplantation is feasible.

Androgens and sexual behavior

Sexual behavior in humans may be classified according to gender role, gender identity, and gender orientation. Sexually dimorphic behavior in humans is generally felt to be determined by postnatal socialization. Recent work in laboratory animals shows that sexual behavior is a function of circulating steroid hormones, particularly androgens. Testosterone given during a critical period in prenatal or immediate postnatal life causes permanent organizational effects on brain structure and function in laboratory animals. Studies in human patients with testicular feminization, 5-alpha-reductase deficiency, congenital adrenal hyperplasia, or prenatal steroid hormone exposure, provide clinical examples of possible effects of prenatal hormone action in the brain as opposed to postnatal socialization. However, these studies do not permit a clear assessment of the role played by either prenatal steroid hormones or postnatal socialization factors in the ultimate expression of sexual behavior in humans.

Urinary and serum steroid concentrations in the management of congenital adrenal hyperplasia. Lack of physiologic correlations

Serum concentrations of 17-hydroxyprogesterone, dehydroepiandrosterone, dehydroepiandrosterone sulfate, progesterone, testosterone, and androstenedione and 24-hour excretion of 17-ketosteroids and pregnanetriol were measured serially in 18 children with congenital adrenal hyperplasia (21-hydroxylase deficiency) during a two-year period. Correlations were sought between results of measurements of these steroids and clinical progress assessed by physical examination and skeletal maturity to determine if measurement of concentration of these substances at a single point in time could be used to gauge the dose of corticosteroids for optimum treatment. We found that these measurements of steroids were generally not useful indicators of optimum control of the disease. Repeated careful clinical examination and assessment of changes in growth velocity and skeletal maturation seem to be the best criteria on which to base dosage of corticosteroids used for therapy.

A dose-response curve for human growth hormone

Although human GH (hGH) has been administered to GH-deficient patients for over 20 yr, there are minimal published data on the relationship of response to dose. We have given hGH on the basis of body weight to 93 prepubertal GH-deficient patients over an initial 12 months of therapy. Their annual growth rate while receiving hGH was 5.58 +/- 2.30 (+/- SD) cm at a dose of 30 mIU/kg, three times a week (tiw; n = 27); 7.31 +/- 1.75 (+/- SD) cm at a dose of 60 mIU/kg, tiw (n = 38); 7.22 +/- 3.12 (+/- SD) cm at a dose of 80 mIU/kg, tiw (n = 12); and 8.94 +/- 1.19 cm (+/- SD) at a dose of 100 mIU/kg, tiw (n = 16). Doubling the dose from 30 to 60 mIU increased the mean rate of growth 1.3 times, and increasing the 30 mIU dose by a factor of 3.3 increased the mean rate of growth 1.6 times. The response (y) as a function of the log-dose (x) is defined by the equation y = -3.12 + 5.80 log x. When the effect of hGH is expressed as the increase in growth rate while receiving therapy, the log-dose relationship is defined by the equation y = -6.09 + 5.67 log x. This dose-response curve provides data which are useful in choosing the best dose of hGH for an individual patient. It also allows a more accurate projection of the costs and benefits of hGH therapy.

Insulin binding to erythrocytes of normal infants, children, and adults: variation with age and sex

The assay of insulin receptors on erythrocytes requires only small amounts of blood and has made it possible to characterize insulin binding in infancy and childhood. To establish normal insulin-binding criteria, we studied 125I binding to insulin receptors on erythrocytes from a large number of normal subjects, including 15 term deliveries, 45 prepubertal children (aged 2 months-12 yr), 15 adult women, and 15 adult men. Insulin binding to cord erythrocytes was significantly higher at tracer and physiological insulin concentrations than binding to cells from any other age group (P less than 0.001). In the prepubertal children after the newborn period, insulin binding was not related to age or sex and did not differ significantly from the binding to cells from adult women. Erythrocytes from adult males, however, bound significantly higher amounts of insulin than did those from adult women or prepubertal children at all insulin concentrations tested (P less than 0.01). Increased binding to cord erythrocytes appeared to be due to an increase in receptor affinity, while the increased binding in adult males was primarily a result of increased receptor concentration. The data confirm previous reports of increased insulin binding to fetal cells and indicate that erythrocyte insulin binding stabilizes at levels similar to those in adult females by the age of 2 months. The increased binding of insulin to erythrocytes from adult males compared to binding to erythrocytes from children or adult females suggests that androgens may increase erythrocyte insulin binding over prepubertal levels.

Monocyte insulin receptors in infants of strictly controlled diabetic mothers

Infants of diabetic mothers have hyperinsulinism at birth, presumably resulting from maternal hyperglycemia or some other derangement of maternal metabolism, and are extremely sensitive to insulin. Such infants have significantly greater numbers of insulin receptors on cord blood monocytes compared to normal infants. To assess the role of maternal diabetic control, nine infants of insulin-dependent diabetic mothers, who were intensively treated during pregnancy, were studied. Maternal blood glucose values were measured during weekly out-patient visits throughout pregnancy, and insulin therapy was given to maintain fasting blood glucose values below 100mg/dl. When necessary, the patients were hospitalized early in pregnancy in order to achieve glucose control, and all patients were hospitalized for up to 2 weeks before delivery for strict glucose control. The mean birth weight (+/- SD) of these infants (3.23 +/- 0.23 kg) was lower than that of nine infants of mothers with gestational diabetes not receiving insulin or intensive efforts at maintenance of normoglycemia (3.99 +/- 0.12; P less than 0.01) and was not significantly different from that of normal infants (3.51 +/- 0.37 kg). Mean cord blood C-peptide levels (+/- SD), determined by RIA, were 1.6 +/- 0.78 ng/ml for infants of these strictly controlled diabetic mothers and 1.4 0.1 ng/ml for normal infants. Scatchard analysis of [125]insulin binding to cord blood monocytes yielded mean receptor numbers for infants of diabetic mothers of 22,500 vs. 105,000 sites/cell for infants of diabetic mothers (P less than 0.001) and 26,600 sites/cell for normal infants. We conclude that the strict control of maternal diabetes during the last trimester of pregnancy prevents fetal hyperinsulinemia and is associated with the development of normal numbers of insulin receptors on the infants' monocytes.

Anorexia nervosa

The clinical and physiologic features of anorexia nervosa seem to be consequences of a complex interaction among psychologic abnormalities, endocrine disturbances, and malnutrition. Although a spectrum of psychologic disorders has been observed, distortion of body image, weight phobia, disordered perception of hunger and satiety, and a sense of ineffectiveness are encountered most frequently. The impaired secretion of luteinizing hormone-releasing factor, release of gonadotropins, and production of estrogens reflect a defect in the hypothalamic-anterior pituitary-gonadal axis. Because most of the endocrine abnormalities are reversible with improved nutrition, they are probably secondary to malnutrition rather than to hypothalamic dysfunction. Hypercarotenemia observed in 16 of 21 patients studied recently seems useful in differentiating anorexia nervosa from other forms of malnutrition and weight loss. A combined medical and psychiatric approach has been successful in drastically reducing the mortality of this disorder.

Hypothalamic atrophy with progressive hypopituitarism in an adolescent girl

The present report describes a 19-yr-old female with progressive hypopituitarism and diabetes insipidus. Pneumoencephalography demonstrated gross atrophy of the hypothalamus and a small pituitary gland. In the face of documented hypothyroidism and hypogonadism, basal pituitary trophic hormones were consistently detectable and responded briskly to releasing factor administration. This combination of an atrophic lesion of the hypothalamus with gradually evolving hypopituitarism but detectable and stimulable anterior pituitary hormones appears to represent a unique form of hypothalamic failure.