Blockade of the mineralocorticoid receptor improves markers of human endothelial cell dysfunction and hematological indices in a mouse model of sickle cell disease.

Increased endothelin-1 (ET-1) levels in patients with sickle cell disease (SCD) and transgenic mouse models of SCD contribute to disordered hematological, vascular, and inflammatory responses. Mineralocorticoid receptor (MR) activation by aldosterone, a critical component of the Renin-Angiotensin-Aldosterone-System, modulates inflammation and vascular reactivity, partly through increased ET-1 expression. However, the role of MR in SCD remains unclear. We hypothesized that MR blockade in transgenic SCD mice would reduce ET-1 levels, improve hematological parameters, and reduce inflammation. Berkeley SCD (BERK) mice, a model of severe SCD, were randomized to either sickle standard chow or chow containing the MR antagonist (MRA), eplerenone (156 mg/Kg), for 14 days. We found that MRA treatment reduced ET-1 plasma levels (p = .04), improved red cell density gradient profile (D50 ; p < .002), and increased mean corpuscular volume in both erythrocytes (p < .02) and reticulocytes (p < .024). MRA treatment also reduced the activity of the erythroid intermediate-conductance Ca2+ -activated K+ channel - KCa 3.1 (Gardos channel, KCNN4), reduced cardiac levels of mRNAs encoding ET-1, Tumor Necrosis Factor Receptor-1, and protein disulfide isomerase (PDI) (p < .01), and decreased plasma PDI and myeloperoxidase activity. Aldosterone (10-8 M for 24 h in vitro) also increased PDI mRNA levels (p < .01) and activity (p < .003) in EA.hy926 human endothelial cells, in a manner blocked by pre-incubation with the MRA canrenoic acid (1 µM; p < .001). Our results suggest a novel role for MR activation in SCD that may exacerbate SCD pathophysiology and clinical complications.

Effect of supplementation with leucine alone, with other nutrients or with physical exercise in older people with sarcopenia: a systematic review.

BACKGROUND: Older adults are at a greater risk of developing sarcopenia as a result of reduced mobility, malnutrition, dietary changes and certain diseases. There are no systematic reviews in the literature analysing the effects of supplementation with leucine alone or as part of a supplement, and with or without physical exercise in older people with sarcopenia. We aimed to systematically review the evidence in intervention studies on the effects of supplementation with leucine, either alone, combined with other supplements, or combined with other supplements and physical exercise in older people with sarcopenia. MATERIALS AND METHODS: Literature searches related to the topic were conducted in three databases (Pubmed/Medline, Cochrane and SciELO) looking for articles published prior to December 2020. This review includes intervention studies in older adults over 60 years of age with a history of sarcopenia where researchers reported on the effects of leucine supplementation, with or without physical exercise, related to the disease's treatments or outcomes. RESULTS: The systematic review identified three intervention studies examining the effect of leucine without physical exercise, one on leucine with physical exercise, seven on leucine paired with another nutrient and without physical exercise, and twelve on leucine paired with another nutrient and physical exercise. The results revealed that leucine supplementation alone and without physical exercise did not improve markers of sarcopenia, whereas interventions pairing leucine with supplements, particularly leucine-enriched protein supplements, are a promising treatment for the improvement of sarcopenic markers, whether with or without physical exercise. CONCLUSIONS: Leucine supplementation, specifically paired with protein supplements, both with and without physical exercise, was found to be an effective dietary intervention for the improvement of sarcopenia. Further dietary interventions are necessary to calculate effective dosage quantities for both leucine and nutrient supplementation as an integral part of the treatment.

Impaired Suppression of Glucagon in Obese Subjects Parallels Decline in Insulin Sensitivity and Beta-Cell Function.

AIM: To examine the relationship between plasma glucagon levels and insulin sensitivity and insulin secretion in obese subjects. METHODS: Suppression of plasma glucagon was examined in 275 obese Hispanic Americans with varying glucose tolerance. All subjects received a 2-hour oral glucose tolerance test (OGTT) and a subset (n = 90) had euglycemic hyperinsulinemic clamp. During OGTT, we quantitated suppression of plasma glucagon concentration, Matsuda index of insulin sensitivity, and insulin secretion/insulin resistance (disposition) index. Plasma glucagon suppression was compared between quartiles of insulin sensitivity and beta-cell function. RESULTS: Fasting plasma glucagon levels were similar in obese subjects with normal glucose tolerance (NGT), prediabetes, and type 2 diabetes (T2D), but the fasting glucagon/insulin ratio decreased progressively from NGT to prediabetes to T2D (9.28 ± 0.66 vs 6.84 ± 0.44 vs 5.84 ± 0.43; P < 0.001). Fasting and 2-hour plasma glucagon levels during OGTT progressively increased and correlated positively with severity of insulin resistance (both Matsuda index and euglycemic hyperinsulinemic clamp). The fasting glucagon/insulin ratio declined with worsening insulin sensitivity and beta-cell function, and correlated with whole-body insulin sensitivity (Matsuda index, r = 0.81; P < 0.001) and beta-cell function (r = 0.35; P < 0.001). The glucagon/insulin ratio also correlated and with beta-cell function during OGTT at 60 and 120 minutes (r = -0.47; P < 0.001 and r = -0.32; P < 0.001). CONCLUSION: Insulin-mediated suppression of glucagon secretion in obese subjects is impaired with increasing severity of glucose intolerance and parallels the severity of insulin resistance and beta-cell dysfunction.

Genotype-Phenotype Features of Germline Variants of the TMEM127 Pheochromocytoma Susceptibility Gene: A 10-Year Update.

PURPOSE: This work aimed to evaluate genotype-phenotype associations in individuals carrying germline variants of transmembrane protein 127 gene (TMEM127), a poorly known gene that confers susceptibility to pheochromocytoma (PHEO) and paraganglioma (PGL). DESIGN: Data were collected from a registry of probands with TMEM127 variants, published reports, and public databases. MAIN OUTCOME ANALYSIS: Clinical, genetic, and functional associations were determined. RESULTS: The cohort comprised 110 index patients (111 variants) with a mean age of 45 years (range, 21-84 years). Females were predominant (76 vs 34, P < .001). Most patients had PHEO (n = 94; 85.5%), although PGL (n = 10; 9%) and renal cell carcinoma (RCC, n = 6; 5.4%) were also detected, either alone or in combination with PHEO. One-third of the cases had multiple tumors, and known family history was reported in 15.4%. Metastatic PHEO/PGL was rare (2.8%). Epinephrine alone, or combined with norepinephrine, accounted for 82% of the catecholamine profiles of PHEO/PGLs. Most variants (n = 63) occurred only once and 13 were recurrent (2-12 times). Although nontruncating variants were less frequent than truncating changes overall, they were predominant in non-PHEO clinical presentations (36% PHEO-only vs 69% other, P < .001) and clustered disproportionately within transmembrane regions (P < .01), underscoring the relevance of these domains for TMEM127 function. Integration of clinical and previous experimental data supported classification of variants into 4 groups based on mutation type, localization, and predicted disruption. CONCLUSIONS: Patients with TMEM127 variants often resemble sporadic nonmetastatic PHEOs. PGL and RCC may also co-occur, although their causal link requires further evaluation. We propose a new classification to predict variant pathogenicity and assist with carrier surveillance.

Correction: Intensive longitudinal modelling predicts diurnal activity of salivary alpha-amylase.

[This corrects the article DOI: 10.1371/journal.pone.0209475.].

Association between Salivary Alpha-Amylase and Executive Functioning in Healthy Children.

The main aim of this study was to confirm the relationship between executive performance and salivary alpha-amylase (SAA) activity in a sample of 64 healthy children (39 boys), and compare it to the association of SAA output and salivary flow rate (SFR). Executive functioning was assessed via fluency, trail-making, rings and inhibition tasks from the Batería de Evaluación Neuropsicológica de la Función Ejecutiva en Niños [Battery of Neuropsychological Assessment for Executive Function in Children] (ENFEN), merged into an ENFEN total score. SAA activity, output, and SFR were measured at baseline, one minute before, and one minute after the end of a neuropsychological testing session. Our results confirmed a direct, linear and significant association between SAA activity and executive functioning, r(64) = .351, p < .05, and extended it to SAA output, r(64) =.431, p < .05. The mean level of SAA output was the best predictor of executive functioning (ß = .431, p < .05) and explained 18.2 % of the variance in ENFEN total score. In sum, and compared to SAA activity, measuring SAA output may be a more precise and indirect marker to assess executive functioning in children.

Association of salivary alpha-amylase and salivary flow rate with working memory functioning in healthy children.

The aim of this study was to examine the association between auditory and visual working memory (WM) performance and salivary alpha-amylase (sAA) and salivary flow rate (SFR) in a sample of 63 children (38 boys). WM was assessed by means of WISC-V subtests: four auditory subtests (Digit Span and Letter-Number Sequencing) and one visual subtest (Picture Span). SAA activity, output, and SFR were measured at baseline (10 min prior to testing), one minute prior to testing, one minute after the end of the auditory WM subtests and one minute after the end of the visual WM subtest. Our statistical analyses showed an association among SAA activity, output and SFR levels and the number of recalled digits in the last attempt score in Letter-Number Sequencing subtest. Specifically, our results showed that working performance in this task was associated with a concurrent decrease in SFR (r(63) = -0.423, p < .05). This salivary measure was the best predictor of this specific index of working memory performance (ß = -0.423, p < .05). These results show that the changes in SFR, which represents changes in parasympathetic tone, could be employed in future studies as a noninvasive marker of working memory performance in child studies.

Association between salivary alpha-amylase and executive functioning in healthy children

The main aim of this study was to confirm the relationship between executive performance and salivary alpha-amylase (SAA) activity in a sample of 64 healthy children (39 boys), and compare it to the association of SAA output and salivary flow rate (SFR). Executive functioning was assessed via fluency, trail-making, rings and inhibition tasks from the Batería de Evaluación Neuropsicológica de la Función Ejecutiva en Niños [Battery of Neuropsychological Assessment for Executive Function in Children] (ENFEN), merged into an ENFEN total score. SAA activity, output, and SFR were measured at baseline, one minute before, and one minute after the end of a neuropsychological testing session. Our results confirmed a direct, linear and significant association between SAA activity and executive functioning, r(64) = .351, p < .05, and extended it to SAA output, r(64) =.431, p < .05. The mean level of SAA output was the best predictor of executive functioning (β = .431, p < .05) and explained 18.2 % of the variance in ENFEN total score. In sum, and compared to SAA activity, measuring SAA output may be a more precise and indirect marker to assess executive functioning in children

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Autonomic reactivity in blood-injection-injury and snake phobia.

OBJECTIVE: This research aimed to study the salivary flow and other autonomic reactions -heart rate (HR) and skin conductance response (SCR)- in blood-injection-injury (BII) phobia and snake phobia participants, under the assumption that exposure to blood-related pictures in BII phobia will provoke an increase in parasympathetic activity that, in turn, will lead to a greater saliva production than other affective contents. METHODS: We selected 18 BII phobia and 14 snake phobia participants along with 22 non-phobia individuals. All participants were exposed to 3 blocks of pictures (12 pictures per block) depicting either mutilations, snakes or neutral, household objects. Saliva samples were taken in the 2-min interval before and after each block. RESULTS: In comparison to other contents, blood-related pictures provoked an increase in salivary flow in BII phobia participants, as well as an increase in the number of SCRs. In the snake phobia group, snake pictures provoked HR acceleration, but the SCRs they elicited did not differ from the SCRs provoked by the blood-related pictures. CONCLUSION: BII phobia individuals react to their phobic object with a series of physiological changes resulting from a sympathetic-parasympathetic co-activation. This is in contrast with other specific phobias (e.g., small animal phobias) that usually show a sympathetically mediated, defensive reactivity when exposed to their disorder-relevant stimuli. These data support the use of therapeutic interventions in BII phobia that may differ in some respect from those used in other specific phobias.

Low levels of morning salivary alpha-amylase activity predict higher number of depressive symptoms in a community sample of children / Bajos niveles de actividad alfa-amilasa salivar predicen un número más elevado de síntomas depresivos en una muestra infantil comunitaria

Models of the etiology of depressive disorders suggest that the onset of a depressive episode is the result of a complex phenomenon based on the interaction between genetic background, critical environmental factors such as life stressors and traumatic events, and the effects of neuroendocrine changes associated with the stress response. Numerous studies have highlighted the usefulness of morning cortisol (C) as a potential predictor of depressive episodes. The aim of this study was to compare the effectiveness of C, salivary alpha-amylase (sAA) activity/output, and the sAA/C ratio in predicting depressive symptoms in a community sample of 99 children aged 8-11 years old. Two saliva samples were obtained in the morning on two different school days. Teachers described their pupils' behavior by using the internalizing problems scales of the Teacher's Report Form (TRF) questionnaire. Our results indicate that, regardless of gender, the best predictor of depressive/withdrawal scores and overall internalizing scores on the TRF was lower mean morning levels of sAA activity. Hence, sAA could be proposed as a biological marker for the risk of developing a first episode of depressive illness in child samples

Los modelos sobre la etiología de los trastornos depresivos sugieren que el inicio de un episodio depresivo es el resultado de un complejo fenómeno que se basa en la interacción entre la carga genética, factores ambientales críticos tales como eventos vitales estresantes y traumáticos, y el efecto de los cambios neuroendocrinos asociados con la respuesta de estrés. Numerosos estudios han resaltado la utilidad de los niveles matutinos de cortisol (C) como un potencial predictor de episodios depresivos. El objetivo del estudio fue comparar la efectividad del C, de la actividad/secreción de la alfa-amilasa salivar (AAs) y de su ratio para predecir la sintomatología depresiva en una muestra comunitaria de 99 niños con edades entre los 8-11 años. Dos muestras de saliva fueron obtenidas en la mañana en dos días escolares. Los profesores describieron el comportamiento de sus estudiantes usando la escala Teacher's Report Form (TRF). Nuestros resultados indican que, con independencia del género, el mejor predictor de las puntuaciones de depresión/aislamiento y del total de alteraciones internalizadas del TRF fue mostrar bajos niveles de actividad de AAs en la mañana. Por lo tanto, esta medida salivar podría ser usada como un marcador biológico del riesgo para el desarrollo de un primer episodio de depresivo infantil

Aldosterone's rapid, nongenomic effects are mediated by striatin: a modulator of aldosterone's effect on estrogen action.

The cellular responses to steroids are mediated by 2 general mechanisms: genomic and rapid/nongenomic effects. Identification of the mechanisms underlying aldosterone (ALDO)'s rapid vs their genomic actions is difficult to study, and these mechanisms are not clearly understood. Recent data suggest that striatin is a mediator of nongenomic effects of estrogen. We explored the hypothesis that striatin is an intermediary of the rapid/nongenomic effects of ALDO and that striatin serves as a novel link between the actions of the mineralocorticoid and estrogen receptors. In human and mouse endothelial cells, ALDO promoted an increase in phosphorylated extracellular signal-regulated protein kinases 1/2 (pERK) that peaked at 15 minutes. In addition, we found that striatin is a critical intermediary in this process, because reducing striatin levels with small interfering RNA (siRNA) technology prevented the rise in pERK levels. In contrast, reducing striatin did not significantly affect 2 well-characterized genomic responses to ALDO. Down-regulation of striatin with siRNA produced similar effects on estrogen's actions, reducing nongenomic, but not some genomic, actions. ALDO, but not estrogen, increased striatin levels. When endothelial cells were pretreated with ALDO, the rapid/nongenomic response to estrogen on phosphorylated endothelial nitric oxide synthase (peNOS) was enhanced and accelerated significantly. Importantly, pretreatment with estrogen did not enhance ALDO's nongenomic response on pERK. In conclusion, our results indicate that striatin is a novel mediator for both ALDO's and estrogen's rapid and nongenomic mechanisms of action on pERK and phosphorylated eNOS, respectively, thereby suggesting a unique level of interactions between the mineralocorticoid receptor and the estrogen receptor in the cardiovascular system.

Salivary alpha-amylase changes promoted by sustained exposure to affective pictures.

We studied the changes in salivary alpha-amylase (sAA) and other psychophysiological indices (heart rate, skin conductance, and corrugator supercilii activity) elicited by sustained exposure to affective pictures. Thirty-nine subjects viewed five blocks of pictures depicting mutilations, human attack, neutral scenes, sport/adventure, and erotica. Each block comprised 12 pictures of the same content. Saliva samples were collected before and after each block of pictures. The results showed that mutilation pictures promoted the greatest increase in sAA activity and output, as well as greater corrugator supercilii activity than pleasant pictures. Skin conductance response did not differ among high arousal picture contents. Changes in sAA varied with the affective valence but not with the arousal ratings of the pictures. Our results point to sAA as an index directly related to the unpleasantness elicited by sustained exposure to affective stimuli.

Activation of the mineralocorticoid receptor increases striatin levels.

BACKGROUND: Aldosterone (ALDO), a critical regulator of sodium homeostasis, mediates its effects via activation of the mineralocorticoid receptor (MR) through mechanisms that are not entirely clear. Striatin, a membrane associated protein, interacts with estrogen receptors in endothelial cells. METHODS: We studied the effects of MR activation in vitro and in vivo on striatin levels in vascular tissue. RESULTS: We observed that dietary sodium restriction was associated with increased striatin levels in mouse heart and aorta and that striatin and MR are present in the human endothelial cell line, (EA.hy926), and in mouse aortic endothelial cells (MAEC). Further, we show that MR co-precipitates with striatin in vascular tissue. Incubation of EA.hy926 cells with ALDO (10(-8) mol/l for 5-24 h) increases striatin protein and mRNA expression, an effect that was inhibited by canrenoic acid, an MR antagonist. Consistent with these observations, incubation of MAEC with ALDO increased striatin levels that were likewise blocked by canrenoic acid. To test the in vivo relevance of these findings, we studied two previously described mouse models of increased ALDO levels. Intraperitoneal ALDO administration augmented the abundance of striatin protein in mouse heart. We also observed that in a murine model of chronic ALDO-mediated cardiovascular damage following treatment with N(G)-nitro-L-arginine methyl ester plus angiotensin II an increased abundance of striatin protein in heart and kidney tissue. CONCLUSION: Our results provide evidence that increased striatin levels is a component of MR activation in the vasculature and suggest that regulation of striatin by ALDO may modulate estrogen's nongenomic effects.

Linfoma testicular: incidencia, descripción epidemiológica y manejo durante el período 2005-2011 / Testicular lymphoma: incidence, epidemiologic description and management during the 2005-2011 period

El linfoma testicular es una patología infrecuente, correspondiendo al 9 por ciento de los cánceres testiculares, presentándose más frecuentemente entre los 60 a 80 años (25-50 por ciento). La presentación clínica más frecuente es el aumento de volumen unilateral e indo/oro. El tipo histológico más común es linfoma difuso de células grandes B (60-90 por ciento). La orquidectomía radical asociada a quimioterapia y radioterapia es la primera línea de tratamiento para los pacientes con enfermedad limitada. Material y método: Estudio retrospectivo descriptivo. Se revisó y filtró la lista de pacientes ingresados al SIGGES como tumor testicular entre enero 2005 a abril 2011. De los pacientes con diagnóstico histológico e inmunohistoquímico compatible, se registraron las características epidemiológicas, estudio, manejo y sobrevida. Posteriormente se realizó un análisis de la base de datos con el programa estadístico SPSS 13. 0. Resultados: De un total de 299 pacientes con el diagnóstico histológico de cáncer testicular, 8 pacientes fueron diagnosticados como linfoma testicular confirmado por histología e inmunohistoquímica. El promedio y mediana de edad fue 52 años y 63 años (18-73) respectivamente. Tres casos (37,5 por ciento) correspondieron a presentaciones secundarias. En 6 de los casos (75 por ciento) el testículo afectado fue el derecho. Histológicamente, el 63 por ciento correspondió a Linfoma difuso de células grande B. Clínicamente, el todos los casos se presentaron con aumento de volumen y con marcadores en rango normal. En 7 casos (8 7, 5 por ciento) el diagnóstico y manejo inicial fue mediante orquidectomía radical, y en un caso por biopsia testicular, con orquidectomía posterior 3 casos presentaron diseminación...

esticular lymphoma is a rare disease, happening in 9 percent of testicular cancers, most commonly between the ages 60 to 80 years (25 percent-50 percent). The most common presentation is unilateral indolent testicular growth. Histology shows a diffuse big B cell lymphoma in most of the cases (60 percent-90 percent). Radical orchiectomy, chemotherapy and radiation are the first line therapy for patients with limited disease. Materials and methods: Retrospective clinical study. We included and filtered the SIGGES list of patients admitted for Testicular Tumor from January 2005 to April 2011. Patients with a compatible diagnosis were analyzed, using SPSS 13.0® as statistical software. Result: Of a total number of 299 testicular cancer patients 8 presented with a histological and inmunnohistochemical testicular lymphoma. Mean age was 52 years and the median 63 years (18-73). ln three cases (37.5 percent) it was a secondary localization. ln 6 cases ( 75 percent) the affected testicle was the right one. 63 percent corresponded to a diffuse big cell B cell Lymphoma. All patients presented normal tumor markers. ln 7 (87,5 percent) cases the initial treatment was radical orchiectomy in one patient the diagnosis was don through a testicular biopsy, and the orchidectomy was differed. 3 cases presented dissemination. In 7 patients adjuvant chemotherapy was performed. Mortal/ty was 38 percent with a 1 7-month follow-up. Conclusion: Testicular lymphoma is a rare condition with bad prognosis. Histology is fundamental for treatment, an in this sense inmunohystochemcal analysis is especially helpful...

Cirugía percutánea renal bilateral simultánea en decúbito supino: experiencia inicial / Percutaneous bilateral renal surgery in supine position: initial experience

La litiasis renal bilateral voluminosa es un desafío quirúrgico para el endourólogo. La cirugía percutánea bilateral simultánea (CPRBS) es una modalidad aceptada, tanto en adultos como niños, sin embargo existe poca literatura al respecto. Presentamos nuestra experiencia de 3 pacientes (6 unidades renales) en posición de Valdivia-Galdakao. Incluimos el primer reporte mundial de un caso de CPRBS tubeless bilateral en de cúbito supino...

Simultaneous bilateral PCNL (SBPCNL) is a safe procedure and can be used effectively in adults as well as in children. In addition to being cost effective, it involves only a single anesthesia with a shorter hospital stay and faster convalescence. We present our initial experience of 3 cases (6 renal units) in supine position. We include the first report to our knowledge of a tubeless SBPCNL in supine position...

Salivary cortisol response to a psychosocial stressor on children diagnosed with attention-deficit/hyperactivity disorder: differences between diagnostic subtypes.

The purpose of the present study was to compare the reactivity of the HPA-axis in children diagnosed with different subtypes of ADHD against a healthy control group. This study included a total of 66 children: 33 children with ADHD diagnoses (10 with prevalent inattentive symptoms, 9 with prevalent hyperactive-impulsive symptoms and 14 with the combined subtype) and 33 healthy controls. The Trier Stress Social Test for Children (TSST-C) was employed as stressor. This test included two main stressors: first, completing a story initiated by an interviewer, and second, executing a timed cognitive task. Saliva samples were then obtained at -1, and +1, +10, +20 and +30 minutes with respect to the stress-inducing task. While the repeated-measures ANOVA showed a statistically significant time effect, the expected cortisol stress-response was not observed in any group. A difference was observed in the response from the hyperactive-impulsive group that was also observed in the AUC(G) comparisons with the subgroups. The ADHD group with prevalent hyperactivity-impulsive symptoms showed more significantly reduced cortisol levels than the control group and other experimental subgroup with prevalent inattentive symptoms.

Salivary Cortisol Response to a Psychosocial Stressor on Children Diagnosed with Attention-Deficit/Hyperactivity Disorder: differences Between Diagnostic Subtypes

The purpose of the present study was to compare the reactivity of the HPA-axis in children diagnosed with different subtypes of ADHD against a healthy control group. This study included a total of 66 children: 33 children with ADHD diagnoses (10 with prevalent inattentive symptoms, 9 with prevalent hyperactive-impulsive symptoms and 14 with the combined subtype) and 33 healthy controls. The Trier Stress Social Test for Children (TSST-C) was employed as stressor. This test included two main stressors: first, completing a story initiated by an interviewer, and second, executing a timed cognitive task.Saliva samples were then obtained at -1, and +1, +10, +20 and +30 minutes with respect to the stress inducing task. While the repeated-measures ANOVA showed a statistically significant time effect, the expected cortisol stress-response was not observed in any group. A difference was observed in the response from the hyperactive-impulsive group that was also observed in the AUCG comparisons with the subgroups. The ADHD group with prevalent hyperactivity-impulsive symptoms showed more significantly reduced cortisol levels than the control group and other experimental subgroup with prevalent inattentive symptoms (AU)

El objetivo del presente estudio fue comparar la reactividad del eje HPA de niños diagnosticados con distintos subtipos de TDAH en comparación con un grupo de control sano. En el estudio fueron incluidos 66 niños: 33 con TDAH (10 con predominio inatento, 9 con predominio hiperactivo-impulsivo, y 14 con sintomatología combinada) y 33 controles sanos. Como estresor se utilizó el Test de Estrés Social de Trier versión infantil (TSST-C). Este test incluye dos estresores: primero, tras una fase de preparación, los niños deben concluir la narración de un cuento previamente iniciada por uno de los dos entrevistadores; y en segundo lugar, tienen que realizar una tarea cognitiva bajo presión de tiempo ante los entrevistadores. Las muestras de saliva fueron obtenidas a -1 y a +1, +10, +20 y +30 minutos después de la inducción de estrés. El ANOVA de medidas repetidas arrojó un efecto tiempo estadísticamente significativo aunque no se observó la respuesta de cortisol esperada en ninguno de los grupos. Se observó una diferencia en la respuesta del grupo de niños con subtipo hiperactivo-impulsivo que también se constató cuando se comparó su AUCG con la del resto de los grupos. El grupo TDAH con predominio hiperactivo-impulsivo mostró niveles significativamente más bajos de cortisol que el grupo control y el resto de los grupos experimentales al enfrentarse al TSST-C (AU)