Eugen J. Schoenle

Apparently Normal Ovarian Differentiation in a Prepubertal Girl with Transcriptionally Inactive Steroidogenic Factor 1 (NR5A1/SF-1) and Adrenocortical Insufficiency

Steroidogenic factor 1 (NR5A1/SF-1) plays an essential role in the development of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes, controlling expression of their many important genes. The recent description of a 46,XY patient bearing a mutation in the NR5A1 gene, causing male pseudohermaphroditism and adrenal failure, demonstrated the crucial role of SF-1 in male gonadal differentiation. The role of SF-1 in human ovarian development was, until now, unknown. We describe a phenotypically and genotypically normal girl, with signs and symptoms of adrenal insufficiency and no apparent defect in ovarian maturation, bearing a heterozygote G-->T transversion in exon 4 of the NR5A1 gene that leads to the missense R255L in the SF-1 protein. The exchange does not interfere with protein translation and stability. Consistent with the clinical picture, R255L is transcriptionally inactive and has no dominant-negative activity. The inability of the mutant (MUT) NR5A1/SF-1 to bind canonical DNA sequences might offer a possible explanation for the failure of the mutant protein to transactivate target genes. This is the first report of a mutation in the NR5A1 gene in a genotypically female patient, and it suggests that NR5A1/SF-1 is not necessary for female gonadal development, confirming the crucial role of NR5A1/SF-1 in adrenal gland formation in both sexes.

Insulin management and metabolic control of Type 1 diabetes mellitus in childhood and adolescence in 18 countries

Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross‐sectional, non‐population‐based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4–6.3 %, mean 5.4 %). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 ± 1.3 % (mean ± SD) compared with 8.9 ± 1.8 % in those aged 12–18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg−124 h−1) in children aged 2–9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37 % (n = 1071) used three or more. Of those on two or three injections daily, 37 % used pre‐mixed insulins, either alone or in combination with short‐ and intermediate‐acting insulin. Pre‐adolescent children on pre‐mixed insulin showed similar HbA1c levels to those on a combination of short‐ and long‐acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long‐acting insulin. Among adolescent boys, lower HbA1c was related to use of more short‐acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few.

Continuing Stability of Center Differences in Pediatric Diabetes Care: do advances in diabetes treatment improve outcome? The Hvidoere Study Group on Childhood Diabetes

OBJECTIVE—To reevaluate the persistence and stability of previously observed differences between pediatric diabetes centers and to investigate the influence of demography, language communication problems, and changes in insulin regimens on metabolic outcome, hypoglycemia, and ketoacidosis. RESEARCH DESIGN AND METHODS—This was an observational cross-sectional international study in 21 centers, with clinical data obtained from all participants and A1C levels assayed in one central laboratory. All individuals with diabetes aged 11–18 years (49.4% female), with duration of diabetes of at least 1 year, were invited to participate. Fourteen of the centers participated in previous Hvidoere Studies, allowing direct comparison of glycemic control across centers between 1998 and 2005. RESULTS—Mean A1C was 8.2 ± 1.4%, with substantial variation between centers (mean A1C range 7.4–9.2%; P < 0.001). There were no significant differences between centers in rates of severe hypoglycemia or diabetic ketoacidosis. Language difficulties had a significant negative impact on metabolic outcome (A1C 8.5 ± 2.0% vs. 8.2 ± 1.4% for those with language difficulties vs. those without, respectively; P < 0.05). After adjustement for significant confounders of age, sex, duration of diabetes, insulin regimen, insulin dose, BMI, and language difficulties, the center differences persisted, and the effect size for center was not reduced. Relative center ranking since 1998 has remained stable, with no significant change in A1C. CONCLUSIONS—Despite many changes in diabetes management, major differences in metabolic outcome between 21 international pediatric diabetes centers persist. Different application between centers in the implementation of insulin treatment appears to be of more importance and needs further exploration.

Inhibition of the Action of Nonsuppressible Insulin-Like Activity on Isolated Rat Fat Cells by Binding to its Carrier Protein

Nonsuppressible insulin-like activity extracted and purified from human serum (NSILA-S) mimics all insulin-like effects in vitro and, after injection, in vivo in the presence of excess insulin antibodies. However, there is no evidence that it exerts acute insulin-like effects in its native form in the circulation, where it is almost completely bound to a specific large molecular weight carrier protein. In this paper we show that partially purified NSILA-S-carrier protein, devoid of endogenous insulin-like activity, inhibits the stimulatory effect of NSILA-S, but not of insulin, on 3-0-methylglucose transport and on lipogenesis from [U-(14)C]glucose in isolated rat fat cells. Concomitantly, it prevents binding of (125)I-labeled NSILA-S to the insulin receptor and to the NSILA-S-binding site. The following explanation is, therefore, offered for the absence of acute insulin-like effects of native NSILA-S in vivo: In native serum NSILA-S occurs almost exclusively as NSILA-S-carrier complex. According to recent findings the passage of this complex through blood capillaries is restricted. The present results indicate that, in addition, it is metabolically inactive, or, at least, possesses reduced metabolic activity. The well-known phenomenon that whole serum, nevertheless, exerts pronounced nonsuppressible insulin-like effects on adipose tissue in vitro seems, therefore, to be mainly caused by the presence of a large molecular weight insulin-like protein not identical to the NSILA-S-carrier complex.

Insulin injection regimens and metabolic control in an international survey of adolescents with type 1 diabetes over 3 years: Results from the Hvidore study group

Abstract. The optimal insulin regimen for paediatric patients with type 1 diabetes remains controversial. Therefore this multicentre study was performed in adolescents over a 3-year period to assess metabolic control, severe hypoglycaemia, and weight gain in relation to insulin injection regimens. Out of 2873 children and adolescents in an international survey in 1995, 872 adolescents (433 boys, 439 girls, mean age in 1995 11.3±2.2 years) were restudied in 1998, relating insulin regimens to HbA1c measured in a central laboratory. In addition, the daily dose of insulin, changes in body mass index (BMI), and events of severe hypoglycaemia were evaluated. Over 3 years, the use of multiple injection regimens increased from 42% to 71%: 251 patients remained on twice daily insulin, 365 remained on multiple injections and 256 shifted from twice daily insulin to multiple injections. In all three subgroups an increase in insulin dose, a deterioration of metabolic control, and an increase in BMI were observed. Metabolic control deteriorated less than expected over 3 years during adolescence (HbA1c 1995: 8.7±1.6%; 1998 observed: 8.9±1.6%, HbA1c expected for 1998: 9.0%). BMI increased more than expected, the increase was greatest in patients switching from twice daily to multiple injections, and higher in females compared to males. Conclusion: in this international study, metabolic control was unsatisfactory in many adolescents with type 1 diabetes irrespective of the insulin regimen. No improvement in metabolic control was observed in this cross-sectional survey, over 3 years in any of the subgroups. Even the group switching from twice to multiple injections did not improve blood glucose control and the increase in body mass index was most pronounced in this group. Conclusive evidence, however, should be based on prospectively planned, randomised therapeutic trials in paediatric patients.

Ovaries and Female Phenotype in a Girl with 46,XY Karyotype and Mutations in the CBX2 Gene

A girl with a prenatal 46,XY karyotype was born with a completely normal female phenotype, including uterus and histologically normal ovaries. In mice with a similar phenotype, the ablation of M33, an ortholog of Drosophila Polycomb, causes male-to-female sex reversal. The analysis of the human homolog of M33, Chromobox homolog 2 (CBX2), in this girl revealed loss-of-function mutations that allowed us, by placing CBX2 upstream of SRY, to add an additional component to the still incomplete cascade of human sex development.

Recombinant human insulin-like growth factor I (rhIGF I) reduces hyperglycaemia in patients with extreme insulin resistance

SummaryThe syndrome of type A insulin resistance is encountered in young women and is characterized by glucose intolerance or frank diabetes mellitus, endogenous hyperinsulinism, insensitivity to insulin administration, acanthosis nigricans and virilization. The insulin resistance is due to reduced cellular insulin binding because of a lack of or defective binding sites and/or because the interaction with the tyrosine kinase of the β-subunit is hindered. This study was undertaken to find out whether hyperglycaemia in these patients may be influenced by the administration of recombinant human insulin-like growth factor I which exerts insulin like effects through the insulin receptor as well as the type 1 insulin-like growth factor I receptor. Recombinant human insulin-like growth factor I was intravenously administered in two subsequent doses of 100 μg/kg body weight to three women with type A insulin resistance. An immediate but slow fall of blood glucose was observed. The glucose disappearance rate was 28.0 μmol/min, i.e. considerably lower than that seen in healthy subjects. The markedly elevated insulin and C-peptide levels fell in a parallel manner to blood glucose but not to normal levels. The results show that recombinant human insulin-like growth factor I, presumably by reacting with the type 1 insulin-like growth factor receptor, can normalize serum glucose levels in patients with severe insulin resistance at least for several hours. We suggest that the potential of recombinant human insulin-like growth factor I to control hyperglycaemia in type A insulin resistant patients should be explored in more depth.

New definition for the partial remission period in children and adolescents with type 1 diabetes

OBJECTIVE To find a simple definition of partial remission in type 1 diabetes that reflects both residual β-cell function and efficacy of insulin treatment. RESEARCH DESIGN AND METHODS A total of 275 patients aged <16 years were followed from onset of type 1 diabetes. After 1, 6, and 12 months, stimulated C-peptide during a challenge was used as a measure of residual β-cell function. RESULTS By multiple regression analysis, a negative association between stimulated C-peptide and A1C (regression coefficient −0.21, P < 0.001) and insulin dose (−0.94, P < 0.001) was shown. These results suggested the definition of an insulin dose–adjusted A1C (IDAA1C) as A1C (percent) + [4 × insulin dose (units per kilogram per 24 h)]. A calculated IDAA1C ≤9 corresponding to a predicted stimulated C-peptide >300 pmol/l was used to define partial remission. The IDAA1C ≤9 had a significantly higher agreement (P < 0.001) with residual β-cell function than use of a definition of A1C ≤7.5%. Between 6 and 12 months after diagnosis, for IDAA1C ≤9 only 1 patient entered partial remission and 61 patients ended partial remission, for A1C ≤7.5% 15 patients entered partial remission and 53 ended, for a definition of insulin dose ≤0.5 units · kg−1 · 24 h−1 5 patients entered partial remission and 66 ended, and for stimulated C-peptide (>300 pmol/l) 9 patients entered partial remission and 49 ended. IDAA1C at 6 months has good predictive power for stimulated C-peptide concentrations after both 6 and 12 months. CONCLUSIONS A new definition of partial remission is proposed, including both glycemic control and insulin dose. It reflects residual β-cell function and has better stability compared with the conventional definitions.

Deletion of Fas in adipocytes relieves adipose tissue inflammation and hepatic manifestations of obesity in mice.

Adipose tissue inflammation is linked to the pathogenesis of insulin resistance. In addition to exerting death-promoting effects, the death receptor Fas (also known as CD95) can activate inflammatory pathways in several cell lines and tissues, although little is known about the metabolic consequence of Fas activation in adipose tissue. We therefore sought to investigate the contribution of Fas in adipocytes to obesity-associated metabolic dysregulation. Fas expression was markedly increased in the adipocytes of common genetic and diet-induced mouse models of obesity and insulin resistance, as well as in the adipose tissue of obese and type 2 diabetic patients. Mice with Fas deficiency either in all cells or specifically in adipocytes (the latter are referred to herein as AFasKO mice) were protected from deterioration of glucose homeostasis induced by high-fat diet (HFD). Adipocytes in AFasKO mice were more insulin sensitive than those in wild-type mice, and mRNA levels of proinflammatory factors were reduced in white adipose tissue. Moreover, AFasKO mice were protected against hepatic steatosis and were more insulin sensitive, both at the whole-body level and in the liver. Thus, Fas in adipocytes contributes to adipose tissue inflammation, hepatic steatosis, and insulin resistance induced by obesity and may constitute a potential therapeutic target for the treatment of insulin resistance and type 2 diabetes.

Comparative trial between insulin glargine and NPH insulin in children and adolescents with type 1 diabetes mellitus.

The objective of this study was to compare the efficacy and safety of insulin glargine, a long-acting insulin analog, with NPH insulin in children and adolescents with type 1 diabetes mellitus (T1DM). In a multicenter, open-label, randomized, 6-month study, 349 patients with TIDM, aged 5-16 years, received insulin glargine once daily or NPH insulin either once or twice daily, based on their prior treatment regimen. Although there was no significant difference between the NPH insulin and insulin glargine treatment groups with respect to baseline to endpoint change in HbA1c levels, fasting blood glucose (FBG) levels decreased significantly more in the insulin glargine group (-1.29 mmol/l) than in the NPH insulin group (-0.68 mmol/L, p = 0.02). The percentage of symptomatic hypoglycemic events was similar between groups; however, fewer patients in the insulin glargine group reported severe hypoglycemia (23% vs 29%) and severe nocturnal hypoglycemia (13% vs 18%), although these differences were not statistically significant (p = 0.22 and p = 0.19, respectively). Fewer serious adverse events occurred in the insulin glargine group than in the NPH insulin group (p < 0.02). A once-daily subcutaneous dose of insulin glargine provides effective glycemic control and is well tolerated in children and adolescents with T1DM.