Are family factors universally related to metabolic outcomes in adolescents with Type 1 diabetes?

AIMS: To assess the importance of family factors in determining metabolic outcomes in adolescents with Type 1 diabetes in 19 countries. METHODS: Adolescents with Type 1 diabetes aged 11-18 years, from 21 paediatric diabetes care centres, in 19 countries, and their parents were invited to participate. Questionnaires were administered recording demographic data, details of insulin regimens, severe hypoglycaemic events and number of episodes of diabetic ketoacidosis. Adolescents completed the parental involvement scale from the Diabetes Quality of Life for Youth--Short Form (DQOLY-SF) and the Diabetes Family Responsibility Questionnaire (DFRQ). Parents completed the DFRQ and a Parental Burden of Diabetes score. Glycated haemoglobin (HbA(1c)) was analysed centrally on capillary blood. RESULTS: A total of 2062 adolescents completed a questionnaire, with 2036 providing a blood sample; 1994 parents also completed a questionnaire. Family demographic factors that were associated with metabolic outcomes included: parents living together (t = 4.1; P < 0.001), paternal employment status (F = 7.2; d.f. = 3; P < 0.001), parents perceived to be over-involved in diabetes care (r = 0.11; P < 0.001) and adolescent-parent disagreement on responsibility for diabetes care practices (F = 8.46; d.f. = 2; P < 0.001). Although these factors differed between centres, they did not account for centre differences in metabolic outcomes, but were stronger predictors of metabolic control than age, gender or insulin treatment regimen. CONCLUSIONS: Family factors, particularly dynamic and communication factors such as parental over-involvement and adolescent-parent concordance on responsibility for diabetes care appear be important determinants of metabolic outcomes in adolescents with diabetes. However, family dynamic factors do not account for the substantial differences in metabolic outcomes between centres.

Panhypopituitarism: genetic versus acquired etiological factors.

OBJECTIVE: Mutations in the genes encoding pituitary transcription factors (mainly PROP1, POUF1 and HESX1) are responsible for familial combined pituitary hormone deficiency (CPHD) and septo-optic dysplasia (SOD) while only a low percentage of mutations are the cause of sporadic forms. Indeed, it has been suggested that environmental rather than genetic factors could be important in the pathogenesis of CPHD. PATIENTS AND METHODS: Thirty-six sporadic patients diagnosed with CPHD or SOD were included in the study. All coding exons and intron-exon boundary regions of PROP1, POUF1 and HESX1 were amplified by PCR and subsequently sequenced. RESULTS: Two novel missense mutations in the HESX1 gene (Q117P, K176T) were identified in two patients. Polymorphisms in PIT1 and PROP1 were also detected. A higher percentage of breech delivery in male patients with CPHD versus females was observed. CONCLUSIONS: The low percentage of mutations found in the most common transcription factors involved in CPHD show that a better characterization of hormonal and morphological phenotypes is necessary for patients with CPHD included in genetic studies, and other genetic or non-genetic factors have to be taken into account.

Heterogeneity of vitamin D receptor gene association with celiac disease and type 1 diabetes mellitus.

OBJECTIVE: Vitamin D has been shown to exert multiple immunomodulatory effects and is known to suppress T-cell activation by binding to the vitamin D receptor (VDR). To determine whether VDR gene polymorphisms are related to the susceptibility to celiac disease, we investigated its implication as a candidate gene in the Basque population. Because celiac disease and type 1 diabetes share common susceptibility loci, we also analyzed families with type 1 diabetes mellitus. METHODS: A total of 37 families with celiac disease and 64 type 1 diabetic families of Basque origin with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (Fok I, Bsm I, Apa I and Taq I). The AFBAC approach was used to test for association. RESULTS: Comparison of VDR genotypes of the patients with those of 88 healthy individuals identified "ff" as a risk genotype for celiac disease [p = 0.01; OR = 3.45 (1.12-10.79)]. On the other hand, a significantly higher frequency of haplotype "fBAt" was observed in the type 1 diabetic group [p(c) = 0.02; OR = 4.4 (1.5-15.3)]. CONCLUSION: Our findings suggest that polymorphisms within the vitamin D receptor gene are markers of susceptibility to or protection from autoimmune diseases, although, at least in the Basque population, association of VDR variants with celiac disease and type 1 diabetes seems to be heterogeneous.

Circulating non-22 kDa growth hormone isoforms after a repeated GHRH stimulus in normal subjects.

The aim of this study was to evaluate the proportion of non-22 kDa GH isoforms in relation to total GH concentration after a repeated GHRH stimulus in healthy subjects. We studied 25 normal volunteers (12 males and 13 females, mean age 13.1 years, range 6-35), who received two GHRH bolus (1.5 mug/kg body weight, i.v.) administered separately by an interval of 120 minutes. The proportion of non-22 kDa GH was determined by the 22 kDa GH exclusion assay (GHEA), which is based on immunomagnetic extraction of monomeric and dimeric 22 kDa GH from serum, and quantitation of non-22 kDa GH isoforms using a polyclonal GH assay. Samples were collected at baseline and at 15-30 min intervals up to 240 min for total GH concentration. Non-22 kDa GH isoforms were measured in samples where peak GH after GHRH was observed. Total GH peaked after the first GHRH bolus in all subjects (median 37.2 ng/ml; range: 10.4-94.6). According to GH response to the second GHRH stimulus, the study group was divided in "non-responders" (n=7; 28%), with GH peak levels lower than 10 ng/ml (median GH: 8.7 ng/ml; range 7.3-9.6) and "responders" (n=18; 72%), who showed a GH response greater than 10 ng/ml (median 17 ng/ml; range 10.1-47.0). The median proportion of non-22 kDa GH on the peak of GH secretion after the first GHRH administration was similar in both groups ("responders" median: 8.6%, range 7-10.9%; "non-responders" median: 8.7%, range 6.7-10.3%), independently of the type of response after the second GHRH. In contrast, the median proportion of non-22 kDa GH was greater at time of GH peak after the second GHRH bolus in the "non-responders" (median 11.4%; range 9.1-14.3%) in comparison with the "responders" (median 9.1%; range 6.7-11.9%; p=0.003). A significant negative correlation between the total GH secreted and the percentage of non-22 kDa isoforms was seen in the "non-responders" (p=0.003). These differences in GH response to repeated GHRH stimulation and in the pattern of GH isoforms at GH peak among subjects might be due to distinct recovery patterns of somatrotrophic function and/or differences in metabolic clearance of GH isoforms.

Persistent differences among centers over 3 years in glycemic control and hypoglycemia in a study of 3,805 children and adolescents with type 1 diabetes from the Hvidøre Study Group.

OBJECTIVE: Twenty-one international pediatric diabetes centers from 17 countries investigated the effect of simple feedback about the grand mean HbA(1c) level of all centers and the average value of each center on changes in metabolic control, rate of severe hypoglycemia, and insulin therapy over a 3-year period. RESEARCH DESIGN AND METHODS: Clinical data collection and determination of HbA(1c) levels were conducted at a central location in 1995 (n = 2,780, age 0-18 years) and 1998 (n = 2,101, age 11-18 years). RESULTS: Striking differences in average HbA(1c) concentrations were found among centers; these differences remained after adjustment for the significant confounders of sex, age, and diabetes duration. They were apparent even in patients with short diabetes duration and remained stable 3 years later (mean adjusted HbA(1c) level: 8.62 +/- 0.03 vs. 8.67 +/- 0.04 [1995 vs. 1998, respectively]). Three centers had improved significantly, four centers had deteriorated significantly in their overall adjusted HbA(1c) levels, and 14 centers had not changed in glycemic control. During the observation period, there were increases in the adjusted insulin dose by 0.076 U/kg, the adjusted number of injections by 0.23 injections per day, and the adjusted BMI by 0.95 kg/m(2). The 1995 versus 1998 difference in glycemic control for the seven centers could not be explained by prevailing insulin regimens or rates of hypoglycemia. CONCLUSIONS: This study reveals significant outcome differences among large international pediatric diabetes centers. Feedback and comparison of HbA(1c) levels led to an intensification of insulin therapy in most centers, but improved glycemic control in only a few.

Good metabolic control is associated with better quality of life in 2,101 adolescents with type 1 diabetes.

OBJECTIVE: It is unclear whether the demands of good metabolic control or the consequences of poor control have a greater influence on quality of life (QOL) for adolescents with diabetes. This study aimed to assess these relations in a large international cohort of adolescents with diabetes and their families. RESEARCH DESIGN AND METHODS: The study involved 2,101 adolescents, aged 10-18 years, from 21 centers in 17 countries in Europe, Japan, and North America. Clinical and demographic data were collected from March through August 1998. HbA(1c) was analyzed centrally (normal range 4.4-6.3%; mean 5.4%). Adolescent QOL was assessed by a previously developed Diabetes Quality of Life (DQOL) questionnaire for adolescents, measuring the impact of diabetes, worries about diabetes, satisfaction with life, and health perception. Parents and health professionals assessed family burden using newly constructed questionnaires. RESULTS: Mean HbA(1c) was 8.7% (range 4.8-17.4). Lower HbA(1c) was associated with lower impact (P < 0.0001), fewer worries (P < 0.05), greater satisfaction (P < 0.0001), and better health perception (P < 0.0001) for adolescents. Girls showed increased worries (P < 0.01), less satisfaction, and poorer health perception (P < 0.01) earlier than boys. Parent and health professional perceptions of burden decreased with age of adolescent (P < 0.0001). Patients from ethnic minorities had poorer scores for impact (P < 0.0001), worries (P < 0.05), and health perception (P < 0.01). There was no correlation between adolescent and parent or between adolescent and professional scores. CONCLUSIONS: In a multiple regression model, lower HbA(1c) was significantly associated with better adolescent-rated QOL on all four subscales and with lower perceived family burden as assessed by parents and health professionals.

Corticoid-induced growth hormone (GH) secretion in GH-deficient and normal children.

Acute administration of corticoids is a potent stimulus of GH secretion in man. To ascertain their mechanism and point of action as well as the suitability of this novel test in the diagnosis of GH-deficient states, normal controls and GH-deficient children were studied. They were selected based on auxological criteria and the GH response to provocative stimuli. The GH-deficient children presented a blunted GH (mean +/- SEM; microgram/L) discharge after insulin-induced hypoglycemia (2.9 +/- 0.4), propranolol-exercise (7.4 +/- 1.5), and clonidine (6.5 +/- 0.8) compared with values in the normal children (7.2 +/- 2.2, 15.8 +/- 2.4, and 15.6 +/- 1.8, respectively). As expected, GH-releasing hormone (GHRH)-induced GH discharge in GH-deficient children (33.2 +/- 4.9) was similar to that in the control children (35.1 +/- 6.0). Administration of 2 mg/m2 body surface dexamethasone, iv, to normal children induced, 3 h later, a mean GH peak of 14.1 +/- 1.2 micrograms/L. This was significantly higher that the corticoid-induced GH peak in GH-deficient children (6.7 +/- 1.1 micrograms/L). The corticoid-induced areas under the secretory curve were 1130 +/- 55 and 616 +/- 54 for the control and GH-deficient children, respectively. GH release in children after dexamethasone administration followed the pattern previously described for adults, i.e. there were no modifications of basal GH levels in the first 2 h, the GH peak appeared around the third hour, and the GH levels remained increased until the fourth hour after dexamethasone administration. Individually considered, practically all control children, but only 2 of 12 GH-deficient children, presented a dexamethasone-induced GH peak over the 10 micrograms/L level. In both normal and GH-deficient patients, corticoids appeared just as potent a stimulus as propranolol-exercise and clonidine, and more potent than hypoglycemia. This new stimulus showed a pattern similar to that of the hypothalamic stimuli, but clearly different with respect to the pituitary one (GHRH), suggesting that corticoids activate GH secretion by acting at hypothalamic level. In conclusion, acute administration of corticoids could be a suitable test in the diagnostic armamentaria of GH-deficient states.

Oral dexamethasone administration: new pharmacological test for the assessment of growth hormone secretion.

Acute intravenous (i.v.) dexamethasone administration has been described recently as a new test for the diagnosis of growth hormone (GH) deficiency. In the present study, a new protocol of dexamethasone administration was evaluated. Twelve normal adults and 18 normal prepubertal children were studied. The dexamethasone i.v. test was performed in six adults at a dose of 4 mg and 12 children at a dose of 2 mg/m2. Blood samples were collected 15 min before, at time zero and every 15 or 30 min during 5 h, resulting in a total of 16 samples. In the remaining six adults and six children, 8 and 4 mg, respectively, of dexamethasone were administered orally at the subject's home, and blood sampling started 90 min later when they arrived at the hospital. Plasma GH was measured by radioimmunoassay. The dexamethasone-induced GH response (mean +/- SEM, micrograms/l) to the i.v. or oral protocol did not differ in either the adults (i.v. 8.2 +/- 2.1; oral 8.0 +/- 1.6) or the children (i.v. 14.9 +/- 1.3; oral 13.6 +/- 1.8). It is concluded that the simpler protocol of acute oral dexamethasone administration hereby presented can be a safe and suitable test of GH secretion.

Childhood-onset congenital adrenal hyperplasia: long-term outcome and optimization of therapy.

Congenital adrenal hyperplasia is a general term applied to several disorders caused by inherited recessive defects of cortisol synthesis. The most common form is 21-hydroxylase deficiency, accounting for 95% of cases. The classical forms have an incidence of one in 15,000 and the non-classical forms about one in 1,000. The classical or severe phenotype presents in the newborn period or early infancy with virilization and adrenal insufficiency, with or without salt-losing; the non-classical or mild phenotype presents in late childhood or early adulthood with signs of hyperandrogenism. This wide range of clinical expression is explained by genetic variation. Although there is a certain amount of genotype-phenotype correlation, discrepancies have been described. During the last 30 years there has been a substantial improvement in diagnosis and treatment of this disease, and patients with CAH now reach adulthood. Treatment of this condition is intended to reduce excessive corticotropin secretion and replace glucocorticoids and mineralocorticoids as physiologically as possible. Clinical management is often complicated by periods of inadequately treated hyperandrogenism, iatrogenic hypercortisolism, or both. Long-term consequences in adult life may include short stature, obesity, diminished bone mass, gonadal dysfunction with low fertility rates and psychosexual dysfunction in females. New treatment approaches are under investigation, such as the use of anti-androgens, inhibitors of estrogen production and adrenalectomy for severely resistant cases.

Molecular analysis of Frasier syndrome: mutation in the WT1 gene in a girl with gonadal dysgenesis and nephronophthisis.

The Wilms' tumor gene (WT1) encodes a protein that is believed to exert transcriptional and tumor-suppressor activities. Mutations in this gene have occasionally been associated with Wilms' tumor (<15% patients) and, more consistently, with three syndromes characterized by urogenital abnormalities (WAGR, Denys-Drash and Frasier syndromes). We report 17 years follow-up of a 29 year-old phenotypic female with 46,XY karyotype, gonadal dysgenesis and nephronophthisis in order to identify possible germline alterations of the WT1 gene. Frasier syndrome was suspected and confirmed by genetic analysis. Sequence analysis permitted the identification of an A40-->G mutation in position +5 in the donor splice site of intron 9. During surgery for streak gonads extirpation, a microscopic gonadoblastoma was found, a typical complication of Frasier syndrome.

Molecular analysis of hereditary hyperferritinemia-cataract syndrome in a large Basque family.

Hereditary hyperferritinemia-cataract syndrome is a genetic condition characterized by constitutively increased serum ferritin values in the absence of iron overload and by bilateral cataract. It has been demonstrated that mutations in the stem loop structure of the iron regulatory element (IRE) located in the 5'-untranslated region of the ferritin L-subunit gene (19q13.1) are responsible for the anomalous expression of this protein. Although not clearly explained, cataract formation seems secondary to the increased levels of ferritin in the lens. We analyzed a large Basque family in order to identify possible germline alterations of the iron regulatory element of the ferritin-L gene in affected individuals and first-degree relatives. All members of the family presented hyperferritinemia and cataract except a young child who had hyperferritinemia but did not present cataract. Sequence analysis permitted the identification of an A40-->G mutation in all members, including this child. This could demonstrate that cataract formation is a consequence of ferritin accumulation in the lens.

Role of glucocorticoids in the neuroregulation of growth hormone secretion.

Elevated glucocorticoid (GC) levels produce a marked impairment in somatic growth in both rodents and primates. In addition, GC play an important role in the regulation of growth hormone (GH) synthesis and secretion. Blunted GH response to stimulation tests in conditions of chronic exposure to excessive cortisol secretion or administration are well documented. In contrast, acute administration of GC to normal human subjects induces a transient increase in plasma GH levels. This dual action of GC on GH secretion is probably due to the fact that they act at different loci; i.e. in the regulation of GH transcription and GHRH and somatostatin receptors at the pituitary level as well as GHRH, somatostatin and GH receptor gene expression at the hypothalamic level.

Dual growth hormone (GH) response to repeated GH releasing hormone stimulus in children and adults.

Several authors have demonstrated that plasma growth hormone (GH) levels as response to acute GH releasing hormone (GHRH) stimulation in adults are decreased by a previous GHRH injection whereas they are maintained in children. Probably the most accepted hypothesis for this finding is the increase in the somatostatinergic tone. The aim of the present study was to evaluate the dual GH response to repeated GHRH stimuli to clarify the possible influence of somatostatinergic activity in the type of response. Eighteen healthy prepubertal children, mean age 9.2 years (range: 6.0-12.9 years) and 19 healthy adult volunteers, mean age 25.5 years (range: 17-35 years) were studied with the GHRH test. An additional group of 10 normal adults with similar characteristics (mean age 31 years, range 25-35 years) were also recruited as a control group for somatostatinergic assessment. The GH response to the first GHRH bolus was similar in both children and adults. However, while children showed a preserved response to the second stimulus, it was diminished in adults. As expected, thyroid stimulating hormone (TSH) was within the normal range in all subjects. When the evolution of TSH was compared between the group of non-responders and the control group, no significant differences were found either at basal time or at 120 min, showing a similar decreasing trend for serum TSH level. The variation of TSH levels were also expressed as the proportion of TSH response after 2 hours compared to the basal level (TSH-120/TSH-0) but no significant differences were found (GHRH non-responders group mean: 73.6%, range: 51.3-93.7; control group mean: 70.7%, range: 62.9-92.5). In conclusion, the results confirm that in adults but not in children, the somatotrope responsiveness to GHRH is inhibited by a previous bolus of GHRH. The finding that the plasma TSH level diminishes in a similar manner in both non-responders and the control group is in agreement with the rejection of the hypothesis of the influence of somatostatin.

Decreased growth hormone response to dexamethasone stimulation test in obese children.

Acute administration of glucocorticoids is a recently described stimulus for growth hormone secretion. The aim of the present study was the assessment of dexamethasone-induced growth hormone secretion in obese children. Dexamethasone iv tests were carried out in 14 normal control and 8 obese children. Growth hormone was measured by radioimmunoassay up to 5 h after dexamethasone administration. Dexamethasone elicited clear growth hormone secretion in normal children (mean peak 12.3 +/- 1.6; area under the curve 682.3 +/- 74.3). In the obese children, dexamethasone induced a slight but significant (p < 0.01) increase in growth hormone over basal values. However, the growth hormone response in this group was significantly lower than in the normal controls, when comparing both mean peak (5.5 +/- 2.3, mean +/- SEM) (p < 0.01) and area under the curve (306.8 +/- 44.5) (p < 0.001).

[Diabetic ketoacidosis: results with two different patterns of insulin administration (author's transl)]. / Cetoacidosis diabética: resultados con dos pautas distintas de terapéutica insulinica.

The response to insulin treatment in 15 children with diabetic ketoacidosis is studied. Insulin continous infusion was administered to nine patients. The other six patients received insulin subcutaneously except one half of the first dose injected by vein as a bolus. Both patterns of insulin administration proved to be equally effective. Anyway the insulin continuous infusion appears as a simple and easier method for a good general control and to prevent hypoglycemic episodes. To prevent a hyperglycemic rebound it is suggested that a dose of subcutaneous insulin must be injected immediately after the insulin infusion is discontinued. A discordance between hyperglycemia correction and the degree of acidosis has been noticed in some patients; this can be corrected decreasing insulin infusion rate.

[Infantile cushing's disease with paradoxical response to dexamethasona due to a probable periodic hormogenesis (author's transl)]. / Enfermedad de Cushing infantil con respuesta paradójica a la dexametasona por probable hormogénesis periódica.

A case of Cushing's disease in a ten year old girl with bilateral diffuse hyperplasia of the adrenal cortex and postoperative enlargment of the sella turcica is presented. The administration of dexamethasone elicited a paradoxical response with a clear elevation of the already high excretion of 17-hydroxycorticoids. The possible mechanisms for this previously described, but infrequent, response to dexamethasone are discussed. It is concluded that: 1) Interpretation of the classical dexamethasone suppression test can occasionally be misleading; and 2) Periodic hormonogenesis may account for this type of paradoxical response.