5-Nitroimidazole refractory giardiasis is common in Matanzas, Cuba and effectively treated by secnidazole plus high-dose mebendazole or quinacrine: a prospective observational cohort study

OBJECTIVE

To evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis.

METHOD

Adults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed.

RESULTS

A total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated.

CONCLUSIONS

5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting.

Short-Term Evaluation of Left Ventricular Mass and Function in Children With Growth Hormone Deficiency After Replacement Treatment

Background: Our study was designed to assess the effects of GHD on nutritional and metabolic parameters, brain natriuretic peptide (BNP) levels, and left ventricular mass (LVM) in prepubertal children and after short-term GH replacement therapy. Materials and Methods: This prospective study enrolled 81 children. We compared 40 GHD children (16 males and 24 females) to 41 healthy children (control group) (18 males and 23 females). All subjects were at Tanner Stage I (aged 7-11 years). At the baseline, a blood sample was drawn and echocardiographic images were obtained. These tests were repeated on the GHD subjects after 6 months of GH replacement therapy. Body surface, weight, size, blood pressure, heart rate, glucose, insulin, HOMA-IR, HOMA-β, QUICKI, cholesterol, HDLc, LDLc, triglycerides, IGF1, and IGFBP3 were measured. Indexed LVM, diastolic and systolic diameter (dD-sD), diastolic and systolic LV function, isovolumic relaxation time, right ventricle function, and BNP levels were obtained through echocardiography. These parameters were correlated to growth factors. Data were analyzed using Student's t-test or U-Mann-Whitney-test and Pearson's correlation, considering p < 0.05 to be significant. Results: Indexed LVM was smaller in GHD patients than in controls, whereas diastolic and systolic functions, BNP, metabolic, and nutritional profiles were similar. After treatment, nutritional and metabolic profiles significantly improved, though diastolic and systolic functions did not seem to have changed. There was a significant increase in LVM. Indexed LVM was similar to that of controls. Significant correlations were obtained between LVM-IGF1 and sD-IGFBP3. Conclusions: GHD in childhood is associated with a lower indexed LVM. In the short-term, GH increases the indexed LVM, while maintaining normal systolic and diastolic functions, BNP, and an improved lipid profile.

Morbility, clinical data and proteomic analysis of IUGR and AGA newborns at different gestational ages

The data are related to the proteomic analysis of 43 newborns with intrauterine growth retardation (IUGR) and 45 newborns with appropriate weight for gestational age (AGA) carried out by separation via 2DE and analyzed by MS–TOF/TOF. All newborns were separated into three gestational age groups, "Very Preterm" 29–32 weeks, "Moderate Preterm" 33–36 weeks, and, "Term" ≥37weeks. From each newborn, blood was drawn three times from birth to 1 month life. High-abundant serum proteins were depleted, and the minority ones were separated by 2DE and analyzed for significant expression differences. The data reflect analytic and clinic variables analyzed globally and categorized by gestational age in relation to IUGR and the optimization of conditions for 2-DE separation. The data from this study are related to the research article entitled "Alterations of Protein Expression in Serum of Infants with Intrauterine Growth Restriction and Different Gestational Ages" (M.D. Ruis-González, M.D. Cañete, J.L. Gómez-Chaparro, N. Abril, R. Cañete, J. López-Barea, 2015) [1]. The present dataset of serum IUGR newborn proteome can be used as a reference for any study involving intrauterine growth restriction during the first month of life.

Presence of the metabolic syndrome in obese children at prepubertal age

BACKGROUND/AIMS

There is a strong debate on the diagnosis and early phenotypic expression of the metabolic syndrome in children. The aim of the present study was to examine the frequency of the metabolic syndrome using various definitions in obese prepubertal and pubertal children.

METHODS

478 (213 females and 265 males) obese children were recruited in three provinces of Spain. Blood pressure (BP), waist circumference, and weight and height were measured, and body mass index was calculated. Glucose, insulin, high-density lipoprotein cholesterol and triacylglycerols were determined. We classified the children according to seven different proposed definitions of the metabolic syndrome.

RESULTS

Regardless of the definition used, the prevalence of the metabolic syndrome (8.3-34.2%) was relatively high in obese children in the prepubertal period as well as in pubertal children (9.7-41.2%). We performed a principal-factor analysis to explain correlations among features of the metabolic syndrome and found that glucose metabolism (factor 1), dyslipidemia (factor 2) and obesity/BP (factor 3) explained 72% of the total variance.

CONCLUSION

Irrespective of the classification used, the metabolic syndrome is not only present in pubertal but also in prepubertal children. International definitions of the metabolic syndrome should also consider criteria specific for children in the prepubertal period, i.e. children aged <10 years.

Fasting and postprandial adiponectin alterations anticipate NEFA and TNF-α changes in prepubertal obese children

BACKGROUND AND AIMS

It has been suggested that adipokine changes might precede changes in plasma non-esterified fatty acids and other obesity metabolic biomarkers. The aim of the present study was to evaluate changes in fasting and postprandial plasma levels of adiponectin, non-esterified fatty acids, and tumor necrosis factor-alpha in prepubertal obese children and age-matched normal-weight children.

METHODS AND RESULTS

Fifty-four children of prepubertal age (34 obese, comprising 23 males and 11 females, and 20 normal-weight comprising 11 males and 9 females) were studied. A standard 438 kcal breakfast was given to both groups. Baseline measurements included anthropometry and plasma lipids. The following parameters were determined in plasma before and after breakfast: glucose, insulin, and C-peptide at baseline and 2h and non-esterified fatty acids, adiponectin, and tumor necrosis factor-alpha at baseline and 1, 2, and 3h. Fasting plasma non-esterified fatty acid levels were lower in the obese versus normal-weight children (P=0.021). Both at baseline and postprandially, plasma adiponectin levels were lower in the obese versus normal-weight children (P<0.001). A trend was observed (P=0.06) that levels of tumor necrosis factor-alpha were lower in the obese versus normal-weight children. Adiponectin was inversely associated with insulin in the obese children after adjustment for BMI and sex (r=-0.401, P=0.025).

CONCLUSION

At prepubertal age, obese children show lower fasting and postprandial plasma adiponectin levels in comparison to normal-weight children, whereas non-esterified fatty acids and tumor necrosis factor-alpha were not yet increased. Therefore, adiponectin appears to be a good marker of early metabolic alterations associated with childhood obesity.

A randomized, controlled, open-label trial evaluating the efficacy and safety of chloroquine in the treatment of giardiasis in children

BACKGROUND

Giardia duodenalis is among the commonest protozoan parasites in the intestinal tract of humans and may cause significant morbidity worldwide. Although there are several antigiardial agents, treatment failures have been commonly reported.

OBJECTIVE

To compare the efficacy and safety of chloroquine (CQ) versus metronidazole (MTZ) in the treatment of children with confirmed G duodenalis mono-infection.

METHODS

A randomized, controlled, open-label trial was carried out at the Cuban Institute of Gastroenterology. One hundred and twenty-two children were randomly assigned to receive either CQ (10 mg/Kg bodyweight twice a day for five days) or MTZ [15 mg/Kg bodyweight divided in three daily does for five days]. All children were asked to provide three faecal samples on days 3, 5 and 7 after treatment completion. Children were considered to be cured, if no Giardia trophozoites or cysts were found in any of the three post-treatment faecal specimens evaluated by direct wet mounts and/or after Ritchie concentration techniques.

RESULTS

The frequency of cure was a little higher for CQ than for MTZ but the difference was not statistically significant. Headache was more common in patients treated with CQ as was bitter taste. Yellowish colouration of the urine was more frequent in the MTZ treated group.

CONCLUSION

Chloroquine, for five days, is as efficacious as the recommended treatment with MTZ in children infected with G duodenalis.

Uric acid is associated with features of insulin resistance syndrome in obese children at prepubertal stage

Elevated plasma uric acid levels are associated with obesity and could be an expression of insulin-resistant state. The aim of the present study was to evaluate plasma uric acid in obese and normal-weight children exclusively at prepubertal stage and its relationship with anthropometric measurements, intake, and features of the insulin resistance syndrome. A study was performed in 34 obese and 20 normal-weight prepubertal children. Nutrient intake was determined using a 72 h recall questionnaire and a consumption food frequency questionnaire. Anthropometric parameters and fasting plasma lipids, glucose, insulin, leptin, adiponectin, tumour necrosis factor (TNF-alpha) and uric acid were measured. Multiple regression analysis was used to identify association of anthropometric parameters, nutrient intake and insulin resistance syndrome variables (arterial blood pressure, plasma glucose, insulin, homeostasis model assessment of insulin resistance index- HOMA- triacylglycerols and, HDL-cholesterol) with uric acid. Plasma uric concentration was significantly higher in the obese group than in the control group and when adjusted by sex, age and BMI was positively associated with tricipital skinfold and insulin resistance, and negatively with adiponectin. In multiple regression analysis, BMI, HDL-cholesterol and adiponectin were independent predictors of plasma uric acid. In conclusion, elevated levels of uric acid in obese children, compared with lean subjects, at the prepubertal period, seems to be an early metabolic alteration that is associated with other features of insulin resistance syndrome.

Mebendazole in parasitic infections other than those caused by soil-transmitted helminths

Mebendazole, a benzimidazole carbamate compound, is currently in use for human medical practice against soil-transmitted helminthiasis (STH) and enterobiasis. However, it has been demonstrated that its spectrum of activity is broad and goes beyond those infections. Several studies provide evidence that this drug, taken at higher doses than used for STH and enterobiasis, could be sufficiently effective on some protozoa, nematodes and cestodes.

Prevalence, risk factors and clinical features associated with intestinal parasitic infections in children from San Juan y Martínez, Pinar del Río, Cuba

A cross-sectional study was carried out in 200 children aged 5-15 years, to examine the presence of intestinal parasitic infections (IPIs) and to assess the risk factors and clinical features associated with them in children in San Juan y Martinez (SIM), Cuba. Three fresh faecal samples were collected from each child and were examined by direct wet mount, brine flotation, formalin-ether and Kato-Katz techniques. Data relating to demography, source of drinking water, personal hygiene habits and clinical features were also collected Living in the rural area was significantly associated with the highest infection rates (p < 0.01). According to clinical features and laboratory examinations, children with abdominal pain were about four times more likely to have IPIs (OR 4.05, CI, 1.11, 13.18) especially soil-transmitted helminths (STH). We suggest that IPIs, especially STH, in SJM should be strongly suspected in children with abdominal pain from rural areas. Targeted and frequent interventions to control these infections are needed in this municipality.

The treatment of giardiasis in children: single-dose tinidazole compared with 3 days of nitazoxanide

Giardia lamblia is among the commonest intestinal protozoa world-wide and may cause significant morbidity, especially in children. Although 5-nitroimidazole compounds have formed the mainstay of giardiasis treatment for several years, the increasing number of reports of refractory cases given these and other antigiardial agents has raised concern and led to a search for other compounds. The aim of the present study was to compare the efficacy and safety, in the treatment of children infected with G. lamblia, of nitazoxanide, given at a dose of 7.5 mg/kg twice a day for 3 days, with those of tinidazole, given as a single dose of 50 mg/kg. Overall, 166 children, each proven to be infected with G. lamblia by the microscopical examination of a faecal sample, were included in the open and randomized trial, each being allocated to receive nitazoxanide or tinidazole. The parents of each treated child were asked to collect two faecal samples from the child between 5 and 10 days after the completion of treatment, for the parasitological follow-up. Only if no G. lamblia were found in both post-treatment samples from a child was that child considered cured. Among the 137 children who completed the study (74 given nitazoxanide and 63 given tinidazole), the frequency of parasitological cure following a single dose of tinidazole was significantly higher than that following six doses of nitazoxanide (90.5% v. 78.4%; P<0.05). Both treatment schedules were well accepted and well tolerated, with only mild, transient and self-limited side-effects reported. The commonest symptom on enrolment, diarrhoea, generally cleared 2-6 days after the initiation of treatment. Although apparently less efficacious than tinidazole, nitazoxanide remains a good candidate for the treatment of children with G. lamblia infection.

Changes in plasma fatty acid composition after intake of a standardised breakfast in prepubertal obese children

Obese patients typically show a pattern of dyslipidaemia and changes in plasma fatty acid composition reflecting abnormalities in lipoprotein metabolism and dietary habits. Animals and obese adults have been widely studied; however, contradictory results have been published in children. The objective was to assess changes in plasma fatty acid composition in total plasma lipids and plasma lipid fractions in obese prepubertal children compared with those of normal weight and to evaluate changes in postprandial plasma fatty acids during a 3 h period after intake of a standardised breakfast. The study was a case-control study with thirty-four obese and twenty normal-weight prepubertal children (Tanner 1). Anthropometric and metabolic variables and fatty acid concentrations were measured in plasma and its fractions. Liquid chromatography was used to separate lipid fractions and GLC to quantify fatty acids. Plasma total fatty acids (TFA), SFA, MUFA and PUFA concentrations were higher in obese than in control children. Except for 18 : 0, 18 : 3n-3, 20 : 4n-6 and n-3 PUFA, all fatty acids in TAG were also elevated in the obese group. Fatty acids 16 : 1n-7, 18 : 0, 18 : 1n-9, 20 : 2n-6, TFA and MUFA significantly decreased between the 2nd and 3rd hour in normal-weight v. obese children. The concentration of 16 : 1n-7 was positively and the proportion of 20 : 4n-6 inversely associated with a significant increase in risk of obesity. Obese prepubertal children show an altered plasma fatty acid profile and concentrations, mainly related to the TAG fatty acid profile, with a lower clearance of fatty acids v. normal-weight prepubertal children.

Recruiting of somatotroph cells after combined somatostatin, GHRH and growth hormone (GH) secretagogue stimulation in a study of pituitary GH reserve in prepuberal female rats

Diagnostic confirmation of growth hormone (GH) deficiency in children and adults is based on stimulation tests designed to assess the pituitary reserve by measuring the amount of GH released into the bloodstream; however, the results obtained by this means cannot provide any direct indication of the amount of GH actually produced by pituitary somatotroph cells. The present paper sought to test the hypothesis that release of GH following administration of specific stimuli does not accurately reflect the somatotroph cell response, and that the amount of GH released into the bloodstream may often be greater or smaller than the amount synthesized. GH release and changes in the proportion of somatotroph cells were charted in prepuberal female Wistar rats, following administration of several different GH stimuli: GHRH (1 microg/kg), GHRP-6 (1 microg/kg), GHRELIN (1 microg/kg) and combined GHRH-based treatments, with or without SRIH pretreatment (1 microg/kg) 90 minutes earlier. Peak serum GH values were recorded 15 minutes after administration of GHRH+GHRELIN and GHRH+GHRP-6; maximum stimulation in terms of an increased proportion of somatotroph cells occurred 15 minutes after combined adminstration of GHRH + GHRELIN. SRIH pretreatment (- 90 min) inhibited GH release, with a subsequent "escape" and lack of response to stimulation which lasted at least 30 minutes except following administration of GHRH. However, combined administration of GHRH+GHRELIN maintained stimulation of the somatotroph cell population. In conclusion, the results suggest that the enhanced GH release prompted by stimulation tests used to diagnose GH deficiency in prepuberal female rats does not fully reflect somatroph cell dynamics, and that not all the GH produced and stored by somatotroph cells is released into the bloodstream.

Postprandial response of trans fatty acids in prepubertal obese children

OBJECTIVES

To evaluate the intake, plasma concentrations and postprandial response of trans fatty acids in obese and control children at prepubertal age in order to detect potential associations with childhood obesity.

DESIGN

Case-control study, clinical dietary intervention with a 428 kcal standardized breakfast and longitudinal 3 h postprandial follow-up for trans fatty acid plasma levels.

SUBJECTS

Fifty-four children aged 6-13 years of both sexes, 34 obese (body mass index >97th percentile for age and sex) and 20 non-obese (control group) at prepubertal period (Tanner I).

MEASUREMENTS

Various anthropometric parameters and sex hormones, fasting insulin and glucose, estimation of dietary trans fatty acid intake and their plasma quantitation in fasting conditions, and for 3 h following intake of a standardized breakfast.

RESULTS

Dietary trans fatty acid intake was less than 0.4% of total energy in both groups, with a trend towards higher intake in obese children. Fasting plasma trans fatty acid concentrations and percentages were similar in both groups. However, trans fatty acid levels at +3 h were significantly higher than at 0 h in obese children, but not in controls (obese, 0 h: 2.38+/-0.29; 3 h: 3.62+/-0.45; controls, 0 h: 2.29+/-0.24; 3.14+/-0.49 mg/dl); cis monounsaturated fatty acid concentrations were not significantly affected by the postprandial interval. Obese children exhibited hyperinsulinemia and insulin resistance; however, trans fatty acid intake or their plasma levels were not associated with them.

CONCLUSION

There is a low intake of trans fatty acids in Southern Spanish children, which is supported by their low concentrations in plasma. No difference in trans fatty acid intake is observed between obese and control children, although plasma levels remain higher in obese than in control children after 3 h of a meal. A marked insulin resistance is seen in obese, but it is not correlated with either trans fatty acid intake or plasma concentration.

Papillary thyroid carcinoma after recombinant GH therapy for Turner syndrome

Turner syndrome (TS) has been included for several years among the indications for GH treatment, generally with satisfactory outcomes. Nevertheless, the long-term effects of this treatment in non-GH deficient patients are not fully known. The incidence of thyroid carcinoma is rare in patients during childhood, it is unusual to find this neoplasia in children under sixteen years old. This article reports the cases of two Spanish patients with papillary thyroid carcinoma after GH treatment for TS. Recent studies have indicated a possible relationship between the GH-IGF axis and the pathogenesis of neoplasias, questioning the chance association of these two pathologies. In line with this, we detected GH receptor expression in the papillary carcinoma cells. Long-term prospective studies are required to clarify the possible effects of GH treatment on the risk of neoplasia.

Low-grade systemic inflammation, hypoadiponectinemia and a high concentration of leptin are present in very young obese children, and correlate with metabolic syndrome

OBJECTIVE

To determine the concentration levels of C-reactive protein (CRP), leptin and adiponectin in obese pre-pubertal children, and their possible relation with metabolic syndrome, fibrinogen and plasminogen activator inhibitor-1.

METHODS

A study was carried out in 51 obese children (aged 6 to 9 years) and the same number of non-obese children (control group), matched by age and sex. (Cross-sectional study of obese children). Body mass index (BMI), waist/hip ratio (WHR) and blood pressure were determined for each child. Serum CRP, leptin, adiponectin, glucose, insulin, lipid profile, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen were all measured.

RESULTS

The levels of CRP serum (1.67+/-0.222 vs 0.92+/-0.16 mg/l) and leptin (15.56+/-1.27 vs 4.68+/-0.62 ng/ml) were significantly higher in obese children. The adiponectin level was significantly higher in non-obese children (11.58+/-0.63 vs 9.64+/-0.49 microg/dl). In the obese group, log. CRP showed a positive correlation with BMI, insulin, homeostasis model assessment (HOMA), triglycerides, alanine aminotransferase (ALT), uric acid, PAI-1, fibrinogen and interleukin 6 (IL-6), and correlated negatively with apolipoprotein A-I and high-density lipoprotein cholesterol (HDL-C). The leptin was positively correlated with BMI, insulin, HOMA, triglycerides and PAI-1 and negatively with Apo A-I and HDL-C. Adiponectin correlated negatively with BMI, insulin, HOMA, and triglycerides.

CONCLUSIONS

Low-grade systemic inflammation, elevated leptin concentration and low adiponectin level are described in very young obese children, correlating with a range of variables of metabolic syndrome. Inflammation and adipocytokines can play an important role in the etiopathogeny of metabolic syndrome.

Hormones regulating lipid metabolism and plasma lipids in childhood obesity

OBJECTIVE

To review the mechanisms by which leptin, insulin and adiponectin influence lipid metabolism and plasma lipids in obesity, as well as to describe the associations between these hormones in prepubertal children.

METHOD

Revision of relevant papers published in the last 5 y related to the interactions of leptin, insulin and adiponectin, with special emphasis on those reporting potential mechanisms by which these hormones regulate lipid metabolism and plasma lipids. We also provide original results concerning the relationships found between plasma lipids and leptin, and insulin and adiponectin in prepubertal obese children.

RESULTS

Recent data in the literature shed new light to explain the effects of both leptin and adiponectin in the regulation of lipid metabolism in peripheral tissues. Activation of the AMP-dependent kinase pathway and subsequent increased fatty acid oxidation seems to be the main mechanism of action of these hormones in the regulation of lipid metabolism. In addition, we have found that insulin plasma levels are positively associated to leptin but negatively correlated with adiponectin in obese children. Adiponectin is negatively associated to plasma lipid markers of metabolic syndrome but positively related to HDL-cholesterol, whereas insulin and leptin show opposite patterns. These results support the effect of adiponectin in increasing insulin sensitivity and decreasing plasma triglycerides.

CONCLUSION

Leptin, insulin and adiponectin are associated hormones that regulate lipid metabolism in childhood. Adiponectin appears to be the missing link to explain the alterations in lipid metabolism and plasma lipids seen in obesity.

A randomized trial comparing mebendazole and secnidazole for the treatment of giardiasis

To compare the efficacy of the two drugs in the treatment of giardiasis, 146 children (aged 5-15 years) with confirmed Giardia lamblia infection were randomly allotted to treatment with mebendazole (200 mg three times daily for 3 days) or secnidazole (30 mg/kg, in a single dose). Parasitological response to treatment was evaluated in each child by the microscopical examination of faecal samples collected 3, 5 and 7 days after he or she had completed treatment. Although the frequency of cure was higher for secnidazole (79.4%) than for mebendazole (78.1%), the difference was not statistically significant (P > 0.05). Both treatment regimens were well tolerated, with only mild, transient and self-limiting side-effects reported. Mebendazole may be preferable to secnidazole in the treatment of giardiasis cases who have an history of intolerance to 5-nitromidazoles, and where infections with Giardia and soil-transmitted helminths frequently co-occur.

Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitro

Growth hormone (GH) is secreted in the anterior pituitary gland by the somatotroph cells. Secretion is regulated by growth hormone releasing hormone (GHRH) and somatostatin. Morever, GH secretagogues (GHS) can exert a considerable effect on GH secretion. In order to determine the effects of chronic treatment with the GHS Ipamorelin on the composition of the somatotroph cell population and on somatotroph GH content, an in vitro analysis was performed of the percentage of somatotroph cells (% of total), the ratio of different GH cell types (strongly/weakly-staining) and individual GH content, in pituitary cell cultures obtained from young female rats receiving Ipamorelin over 21 days (Ipamorelin group) and the effects were compared with those of GHRH (GHRH group) or saline (saline group). The ultrastructure of somatotroph cells did not change, but the volume density of secretion granules was increased (P<0.05) by previous in vivo Ipamorelin or GHRH treatment. In 3-day basal pituitary cell monolayer cultures, the percentage of somatotroph cells showed no modifications between groups, nor was there any change in the ratio of strongly/weakly immunostaining GH cells. In the Ipamorelin group alone, in vitro treatment with Ipamorelin (10(-8) M), or GHRP 6 (10(-8) M), or GHRH (10(-8) M) for 4 hours, increased the percentage of somatotroph cells, without modifying the ratio of strongly/weakly immunostained GH cells. Basal intracellular GH content in somatotroph cells over 4 hours was lower in the Ipamorelin group and the GHRH group than in the saline group. Only in the Ipamorelin group did Ipamorelin (10(-8) M), GHRP 6 (10(-8) M) and GHRH (10(-8) M) prompt increased intracellular GH content. These data suggest that, at least in the young female rat, the GHS Ipamorelin is able to exert a dynamic control effect on the somatotroph population and on GH hormone content.

Sex hormone-binding globulin as a marker for hyperinsulinemia and/or insulin resistance in obese children

OBJECTIVE

A relationship between hyperinsulinemia and decreased serum sex hormone-binding globulin (SHBG) has been described in adults. We evaluated the usefulness of SHBG as an index of hyperinsulinemia and/or insulin resistance in obese children (aged 6-9 years) of both sexes and its possible influence on the androgenic status.

DESIGN

We carried out a cross-sectional study of cases and controls. We studied 61 obese children (22 males, 39 females) with body mass index (BMI) superior to the 90(th) percentile and a control group of age- and sex-matched non-obese children. We measured serum glucose, insulin, TSH, free thyroxine, 17beta-estradiol, testosterone and SHBG. Also, we correlated these parameters with anthropometric measures.

RESULTS

The obese group presented significantly elevated levels of insulin (P=0.001) and insulin/glucose ratio (P=0.0012) compared with the control group. SHBG (P=0.0001) and testosterone (P=0.0169) levels were significantly lower than those in the non-obese group. We did not find any difference in the free androgen index (FAI). Fasting insulin (r=-0.4512; P<0.001), BMI (r=-0.3185; P<0.05) and testosterone (r=-0.3705; P<0.01) were inversely correlated with SHBG concentration. According to multivariate analyses, insulin was the only independent predictor factor for serum SHBG concentration in the obese group (r partial=0.1280; P=0.0171).

CONCLUSIONS

In summary, at this age there is a strong relationship between insulin and SHBG. The changes in SHBG levels of the obese group did not affect FAI and, therefore, they did not cause changes in the androgenic status. Our data support the role of insulin in the regulation of serum SHBG levels.

Infantile obesity: a situation of atherothrombotic risk?

Obesity is a major risk factor for cardiovascular disease frequently associated with hypertension, dyslipidemia, and diabetes. In recent years, alterations in the hemostatic system have been added to these dysfunctions. We analyzed some of these alterations in coagulation and fibrinolysis in obese children (6 to 9 years old) of both sexes. We studied 61 obese children (mean body mass index [BMI], 22.35 kg/m2; 95% confidence interval [CI], 21.82 to 22.87) and 70 non-obese children (mean BMI, 16.58 kg/m2; 95% CI, 16.24 to 16.93) as a control group. The obese subjects presented significantly elevated values for insulin (P < .001), tissue-plasminogen activator ([t-PA] P < .001), plasminogen activator inhibitor-1 ([PAI-1] P < .001), and fibrinogen (P < .001) with respect to the control group. We found no significant differences in the concentration of glucose and fragment 1 + 2 of prothrombin (F1 + 2). In the obese subjects, insulin, PAI-1, and F1 + 2 were positively correlated with the BMI. On the other hand, t-PA was correlated with insulin and PAI-1 but not with the BMI. Therefore, in the obese children, there was an increment of the risk factors for cardiovascular disease.

Morphological changes to somatotroph cells and in vitro individual GH release, in male rats treated with recombinant human GH

The effect of in vivo chronic administration of recombinant human growth hormone (rhGH) on morphology and individual GH release in somatotroph cells was evaluated in young male Wistar rats. Over an 18-day period, 30-day-old male rats were injected daily with 1.5 1U rhGH/kg (GPG group) or saline (VPG group) by subcutaneous injection. Electron-immunocytochemical, ultrastructural and morphometric studies of somatotroph cells were carried out. Additionally, rat pituitary cells were dispersed and overall and individual GH release was studied by radioimmunoassay and cell immunoblot assay (quantified by image analysis), respectively. The ultrastructure and size of somatotroph cells did not change, but volume density of secretion granules was reduced (p<0.01) by previous in vivo GH treatment. At four days, basal GH release of rat pituitary cell monolayer cultures was lower in the GPG group than in the VPG group (p<0.05); after 12 hours of culture, GHRH stimulation of GH release was lower in the GPG group than in the VPG group (p<0.05), and GHRH+SRIH inhibited GH release in the GPG group (p<0.05), but not in the VPG group. The percentage of somatotroph cells was not modified, but the ratio of strongly/weakly GH-immunostained cells had changed; weakly GH-immunostained cells increased from 34% to 55%. Moreover, in vitro treatment with GHRH, SRIH, and both, easily changed the strongly/weakly GH-immunostained cell ratio. Individual GH release, however, was not changed by previous in vivo GH treatment, although GHRH preferably stimulated a subpopulation of GH cells and SRIH did not inhibit individual GH release. These data suggest that exogenous chronic rhGH treatment down-regulates somatotroph function by modifying the proportion of GH cell subpopulation.