1,721,045 research outputs found
Glucose Metabolism in Children With Growth Hormone Deficiency
Full text linkBackgroundThe growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis has a fundamental impact on glucose metabolism. Therefore, both untreated GH deficiency (GHD) and GH treatment (GHT) may be associated with some metabolic alterations, although the abnormalities of glucose metabolism have been investigated by relatively few studies as main outcomes.AimThe present review summarizes the available data on glucose metabolism in children with GHD, providing an overview of the current state of the art in order to better clarify the real metabolic impact of GHD and GHT.MethodsAmong all the existing studies, we evaluated all original studies that fulfilled our criteria for analysis reporting parameters of glucose metabolism as the primary or secondary objective.ResultsThe reported impact of GHD per se on glucose metabolism is quite homogeneous, with the majority of studies reporting no significant difference in metabolic parameters between GHD children and controls. Conversely, GHT proves to be more frequently associated with a subtle form of insulin resistance, while both fasting glucose and HbA1c levels remain almost always within the normal range.ConclusionThe different methods to study glucose metabolism, the heterogeneity of the populations evaluated, the different doses of GH used together with the variable duration of follow-up may be responsible for discrepancy in the results. Long-term longitudinal studies having glucose homeostasis as their primary outcome are still needed in order better to clarify the real metabolic impact of GHD and GHT in children
Circulating Irisin Levels in Children with GH Deficiency before and after 1 Year of GH Treatment
Full text linkPurpose To evaluate circulating irisin levels in children with GH deficiency (GHD) and any relation with clinical and metabolic parameters. Patients Fifty-four prepubertal children (mean age, 7.4 ± 0.8 years) with idiopathic GHD treated with GH for at least 12 months and 31 healthy short children as control subjects. Methods Body height, body mass index (BMI), waist circumference (WC), IGF-I, HbA1c, lipid profile, fasting and after-oral glucose tolerance test glucose and insulin, insulin sensitivity indices, and irisin levels were evaluated at baseline and after 12 months of GH replacement (GHR). Results At baseline, children with GHD, in addition to having lower growth velocity (P < 0.001), GH peak after stimulation tests (both P < 0.001), and IGF-I (P < 0.001), showed significantly lower irisin (P < 0.001) and higher BMI (P < 0.001) and WC (P = 0.001), without any difference in metabolic parameters, than control subjects. After GHR, children with GHD showed a significant increase in height (P < 0.001), growth velocity (P < 0.001), IGF-I (P < 0.001), fasting glucose (P = 0.002) and insulin (P < 0.001), homeostasis model assessment estimate of insulin resistance (P < 0.001), and irisin (P = 0.005), with a concomitant decrease in BMI (P = 0.001) and WC (P = 0.003). In multivariate analysis, the independent variables significantly associated with irisin were BMI (P = 0.002) and GH peak (P = 0.037) at baseline and BMI (P = 0.005), WC (P = 0.018), and IGF-I (P < 0.001) during GHR. Conclusions We report that GHR leads to an increase in irisin levels, strongly related to a decrease in BMI and WC, and to an increase in IGF-I; these changes are among the main goals of GHR. These data confirm the favorable effects of GHR in children
Comparison between euglycemic hyperinsulinemic clamp and surrogate indices of insulin sensitivity in children with growth hormone deficiency
Full text linkObjective: Data about the impact of growth hormone treatment (GHT) on insulin sensitivity in children are quite controversial, due to the different surrogate indices that have been used. Design: We evaluated insulin sensitivity through the euglycemic hyperinsulinemic clamp, considered the gold standard technique, in 23 children affected by growth hormone deficiency (GHD) at baseline and after 12. months of GHT and in 12 controls with short stature at baseline, and we compared the clamp-derived index (M-value) with the most commonly used surrogate index of insulin sensitivity, as ISI Matsuda, and with circulating plasma markers of insulin sensitivity, as adiponectin and resistin levels. Results: At baseline, no significant difference in all metabolic parameters between GHD children and control subjects was found. After 12. months of GHT, GHD children showed a significant increase in fasting insulin (p <. 0.001) and resistin (p = 0.028) and a decrease in ISI Matsuda (p <. 0.001) and M-value (p. <. 0.001), without significant change in fasting glucose, HbA1c and adiponectin. In GHD children, M-value showed a significant but weak correlation with ISI Matsuda (rho 0.418, p = 0.047) at baseline, while no correlation with other parameters was found. After 12. months of GHT, M-value did not show any significant correlation with any other metabolic parameter analyzed. Conclusions: This study highlights the limit of the evaluation of insulin sensitivity performed through surrogate indices or circulating markers, which may lead to controversial data and do not correlate with the gold standard technique to evaluate insulin sensitivity
Improved insulin sensitivity and secretion in prediabetic patients with adrenal insufficiency on dual-release hydrocortisone treatment: a 36-month retrospective analysis
Full text linkObjective: Dual-release hydrocortisone (DR-HC) provides physiological cortisol exposure, leading to an improvement of anthropometric and metabolic parameters. The aim of the study was to evaluate the effects of DR-HC on insulin secretion and sensitivity and cardiometabolic risk, indirectly expressed by the visceral adiposity index (VAI). Design and Patients: Retrospective analysis of 49 patients, 13 with primary and 36 with secondary adrenal insufficiency (AI), respectively, on conventional glucocorticoid treatment at baseline and switched to DR-HC for 36 months. Overall, 24 patients had AI-pre–diabetes (impaired fasting glucose, impaired glucose tolerance and the combination), and 25 had AI-normal glucose tolerance (NGT). Measurements: Clinical and metabolic parameters, including VAI, insulin secretion and sensitivity indexes (fasting insulinaemia, AUC2 h insulinaemia, oral disposition index [Dio] and ISI-Matsuda), were evaluated. Results: In patients with AI-NGT and AI-prediabetes, a significant decrease in BMI (P =.017 and P <.001), waist circumference (P =.008 and P <.001), HbA1c (P =.034 and P =.001) and a significant increase in HDL-C (P =.036 and P =.043) was, respectively, observed. In addition, in prediabetic patients, only we found a significant decrease in insulinaemia (P =.014), AUC2 h insulinaemia(P =.038) and VAI (P =.001), in concomitance with a significant increase in DIo (P =.041) and ISI-Matsuda (P =.038). Conclusions: Long-term DR-HC therapy is associated with an improvement in insulin secretion and sensitivity in patients with prediabetes. However, all patients appear to benefit from the treatment in terms of improvement of metabolic and anthropometric parameters. Larger studies are required to confirm our preliminary data
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Higher cardiometabolic risk in idiopathic versus autoimmune type 1 diabetes: A retrospective analysis
Full text linkBackground: Idiopathic type 1 diabetes mellitus (IDM) is characterized by an onset with insulinopenia and ketoacidosis with negative β-cell autoimmunity markers and lack of association with HLA. The aim of the study is to compare the clinical and metabolic parameters, the macro and microvascular complications, the adipose tissue dysfunction and the insulin secretion and sensitivity indexes in patients with IDM and autoimmune type 1 diabetes mellitus (ADM) at clinical onset. Methods: Thirty patients with IDM and 30 with ADM, matched for age and gender, were retrospectively analyzed. BMI, waist circumference, lipids, glycemia, HbA1c, insulin requirement, glutamic oxaloacetic and glutamic pyruvic transaminases (GOT and GPT), glucagon stimulated c-peptide (GSC-pep) test levels, M value during hyperinsulinemic euglycemic clamp and Visceral Adiposity Index (VAI) were obtained from our database. Results: Patients with IDM showed a significantly higher BMI (p 0.012), WC (p 0.07), VAI (p 0.004), LDL-cholesterol (p 0.027), GOT (p 0.005), GPT (p 0.001), M value (p 0.006) and GSC-pep peak (p 0.036), with concomitant lower HDL-cholesterol (p < 0.001), than patients with ADM. In addition, patients with IDM showed a more marked familial history for diabetes (p 0.005) and a higher percentage of hepatic steatosis (p 0.001), visceral obesity (p 0.032) and hypercholesterolemia (p 0.007) compared to patients with ADM. Conclusions: Patients with IDM show many metabolic complications at onset, such as visceral obesity, hepatic steatosis and hypercholesterolemia and a higher cardiometabolic risk, than patients with ADM, similarly to patients with type 2 diabetes at onset
The metabolic outcomes of growth hormone treatment in children are gender specific
Full text linkOBJECTIVE:
To evaluate the impact of gender on the clinical and metabolic parameters in prepubertal growth hormone deficiency (GHD) children at diagnosis and during GH treatment (GHT).
DESIGN:
The data of 105 prepubertal children (61 males, 44 females, mean age 6.8 ± 0.7 years) affected by idiopathic GHD were retrospectively evaluated.
METHODS:
Body height, BMI, waist circumference (WC), IGF-I, HbA1c, lipid profile, fasting and after-OGTT glucose and insulin levels, insulin sensitivity and secretion indices were evaluated at baseline and after 24 months of GHT.
RESULTS:
At baseline, no significant difference was found in all clinical, hormonal and metabolic parameters between males and females. After 24 months of GHT, both males and females showed a significant increase in height (both P < 0.001), BMI (both P < 0.001), WC (P < 0.001 and P = 0.004, respectively), IGF-I (both P < 0.001), fasting glucose (P < 0.001 and P = 0.001, respectively), fasting insulin (both P < 0.001) and Homa-IR (both P < 0.001), with a concomitant significant decrease in insulin sensitivity index (ISI) (both P < 0.001) and oral disposition index (DIo) (P = 0.001 and P < 0.001, respectively). At 24 months of GHT, females showed significantly higher BMI (P = 0.027), lower ISI (P < 0.001) and DIo (P < 0.001), in concomitance with a significant greater change from baseline to 24 months of BMI (P = 0.013), WC (P < 0.001), ISI (P = 0.002) and DIo (P = 0.072), although the latter does not reach statistical significance.
CONCLUSIONS:
Twenty-four months of GHT in prepubertal children leads to different metabolic outcomes according to gender, with a greater reduction in insulin sensitivity in females, regardless of auxological and hormonal parameters. Therefore, prepubertal GHD females should probably need a more proper monitoring in clinical practice
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