Activational and organizational effects of testosterone on the number of mating partners and reproductive success in males of a social rodent.

The timing of exposure to the steroid hormone, testosterone, produces activational and organizational effects in vertebrates. These activational and organizational effects are hypothesized to relate with the number of female mating partners and reproductive success in males. We tested this hypothesis by examining 151 wild degu (Octodon degus) males across a 10-year study. We quantified the association between adult serum testosterone levels (i.e., an indirect index of adult activational effects) and anogenital distance (AGD) length (i.e., a direct index of fetal organizational effects), and their interaction on the number of female mating partners and reproductive success. We found no evidence of an association between adult male serum testosterone levels and the number of female mating partners, or between adult male serum testosterone levels and reproductive success. However, male AGD was positively associated with reproductive success, but not so with the number of female mating partners. Additionally, the positive association between male AGD and male reproductive success was mediated by the number of mates. Our findings do not support major roles of activational or organizational effects of testosterone on the number of female mating partners and its consequences on male reproductive success. Instead, our results suggest that compared with individual male attributes, the female social environment plays a more important role in driving male reproductive success.

Influence of Seropositivity against Adenovirus-36 on the Risk of Obesity and Insulin Resistance in the Child Population of Southern Chile.

Background: Previous infection with Adenovirus-36 (HAdv-D36) has been associated with adipogenesis and glycemic regulation in cell culture and animal models. In humans, HAdv-D36 antibodies correlate with increased obesity risk yet paradoxically enhance glycemic control across various demographics. This study assesses the association of HAdv-D36 seropositivity with obesity, lipid, and glycemic profiles among school-aged children. Methods: We evaluated 208 children aged 9-13, categorized by BMI z-scores into normal weight (-1 to +1), overweight (+1 to +2), and obese (>+3). Assessments included anthropometry, Tanner stage for pubertal development, and biochemical tests (relating to lipids, glucose, and insulin), alongside HAdv-D36 seropositivity checked via ELISA. Insulin resistance was gauged using Chilean pediatric criteria. Results: The cohort displayed a high prevalence of overweight/obesity. HAdv-D36 seropositivity was 5.4%, showing no correlation with nutritional status. Additionally, no link between HAdv-D36 seropositivity and lipid levels was observed. Notably, insulin levels and HOMA-RI were significantly lower in HAdv-D36 positive children (p < 0.001). No cases of insulin resistance were reported in the HAdv-D36 (+) group in our population. Conclusions: HAdv-D36 seropositivity appears to decrease insulin secretion and resistance, aligning with earlier findings. However, no association with obesity development was found in the child population of southern Chile.

A Computer Vision-Based System to Help Health Professionals to Apply Tests for Fall Risk Assessment.

The increase in life expectancy, and the consequent growth of the elderly population, represents a major challenge to guarantee adequate health and social care. The proposed system aims to provide a tool that automates the evaluation of gait and balance, essential to prevent falls in older people. Through an RGB-D camera, it is possible to capture and digitally represent certain parameters that describe how users carry out certain human motions and poses. Such individual motions and poses are actually related to items included in many well-known gait and balance evaluation tests. According to that information, therapists, who would not need to be present during the execution of the exercises, evaluate the results of such tests and could issue a diagnosis by storing and analyzing the sequences provided by the developed system. The system was validated in a laboratory scenario, and subsequently a trial was carried out in a nursing home with six residents. Results demonstrate the usefulness of the proposed system and the ease of objectively evaluating the main items of clinical tests by using the parameters calculated from information acquired with the RGB-D sensor. In addition, it lays the future foundations for creating a Cloud-based platform for remote fall risk assessment and its integration with a mobile assistant robot, and for designing Artificial Intelligence models that can detect patterns and identify pathologies for enabling therapists to prevent falls in users under risk.

A Star Network of Bipolar Memristive Devices Enables Sensing and Temporal Computing.

Temporal (race) computing schemes rely on temporal memories, where information is represented with the timing of signal edges. Standard digital circuit techniques can be used to capture the relative timing characteristics of signal edges. However, the properties of emerging device technologies could be particularly exploited for more efficient circuit implementations. Specifically, the collective dynamics of networks of memristive devices could be leveraged to facilitate time-domain computations in emerging memristive memories. To this end, this work studies the star interconnect configuration of bipolar memristive devices. Through circuit simulations using a behavioral model of voltage-controlled bipolar memristive devices, we demonstrated the suitability of such circuits in two different contexts, namely sensing and "rank-order" coding. We particularly analyzed the conditions that the employed memristive devices should meet to guarantee the expected operation of the circuit and the possible effects of device variability in the storage and the reproduction of the information in arriving signal edges. The simulation results in LTSpice validate the correct operation and confirm the promising application prospects of such simple circuit structures, which, we show, natively exist in the crossbar geometry. Therefore, the star interconnect configuration could be considered for temporal computations inside resistive memory (ReRAM) arrays.

High-Throughput Mechanical Exfoliation for Low-Cost Production of van der Waals Nanosheets.

A method is presented for scaling up the production of flakes of van der Waals materials via mechanical exfoliation. Using a roll-to-roll setup and an automatized, massive parallel exfoliation process, adhesive tapes with a high density of nanosheets of van der Waals materials are produced. The technique allows for obtaining a good trade-off between large lateral size and excellent area scalability, while also maintaining low cost. The potential of the method is demonstrated through the successful fabrication of field effect transistors and flexible photodetectors in large batches. This low-cost method to produce large area films out of mechanically exfoliated flakes is very general, and it can be applied to a variety of substrates and van der Waals materials and, moreover, it can be used to combine different van der Waals materials on top of each other. Therefore, it is believed that this production method opens an interesting avenue for fabrication of low-cost devices while maintaining a good scalability and performance.

Large Magnetoresistance of Isolated Domain Walls in La2/3 Sr1/3 MnO3 Nanowires.

Generation, manipulation, and sensing of magnetic domain walls are cornerstones in the design of efficient spintronic devices. Half-metals are amenable for this purpose as large low field magnetoresistance signals can be expected from spin accumulation at spin textures. Among half metals, La1- x Srx MnO3 (LSMO) manganites are considered as promising candidates for their robust half-metallic ground state, Curie temperature above room temperature (Tc = 360 K, for x = 1/3), and chemical stability. Yet domain wall magnetoresistance is poorly understood, with large discrepancies in the reported values and conflicting interpretation of experimental data due to the entanglement of various source of magnetoresistance, namely, spin accumulation, anisotropic magnetoresistance, and colossal magnetoresistance. In this work, the domain wall magnetoresistance is measured in LSMO cross-shape nanowires with single-domain walls nucleated across the current path. Magnetoresistance values above 10% are found to be originating at the spin accumulation caused by the mistracking effect of the spin texture of the domain wall by the conduction electrons. Fundamentally, this result shows the importance on non-adiabatic processes at spin textures despite the strong Hund coupling to the localized t2g electrons of the manganite. These large magnetoresistance values are high enough for encoding and reading magnetic bits in future oxide spintronic sensors.

Interhemispheric competition during sleep.

Our understanding of the functions and mechanisms of sleep remains incomplete, reflecting their increasingly evident complexity1-3. Likewise, studies of interhemispheric coordination during sleep4-6 are often hard to connect precisely to known sleep circuits and mechanisms. Here, by recording from the claustra of sleeping bearded dragons (Pogona vitticeps), we show that, although the onsets and offsets of Pogona rapid-eye-movement (REMP) and slow-wave sleep are coordinated bilaterally, these two sleep states differ markedly in their inter-claustral coordination. During slow-wave sleep, the claustra produce sharp-wave ripples independently of one another, showing no coordination. By contrast, during REMP sleep, the potentials produced by the two claustra are precisely coordinated in amplitude and time. These signals, however, are not synchronous: one side leads the other by about 20 ms, with the leading side switching typically once per REMP episode or in between successive episodes. The leading claustrum expresses the stronger activity, suggesting bilateral competition. This competition does not occur directly between the two claustra or telencephalic hemispheres. Rather, it occurs in the midbrain and depends on the integrity of a GABAergic (γ-aminobutyric-acid-producing) nucleus of the isthmic complex, which exists in all vertebrates and is known in birds to underlie bottom-up attention and gaze control. These results reveal that a winner-take-all-type competition exists between the two sides of the brain of Pogona, which originates in the midbrain and has precise consequences for claustrum activity and coordination during REMP sleep.

Single spikes drive sequential propagation and routing of activity in a cortical network.

Single spikes can trigger repeatable firing sequences in cortical networks. The mechanisms that support reliable propagation of activity from such small events and their functional consequences remain unclear. By constraining a recurrent network model with experimental statistics from turtle cortex, we generate reliable and temporally precise sequences from single spike triggers. We find that rare strong connections support sequence propagation, while dense weak connections modulate propagation reliability. We identify sections of sequences corresponding to divergent branches of strongly connected neurons which can be selectively gated. Applying external inputs to specific neurons in the sparse backbone of strong connections can effectively control propagation and route activity within the network. Finally, we demonstrate that concurrent sequences interact reliably, generating a highly combinatorial space of sequence activations. Our results reveal the impact of individual spikes in cortical circuits, detailing how repeatable sequences of activity can be triggered, sustained, and controlled during cortical computations.

Neurons in the brain form thousands of connections, or synapses, with one another, allowing signals to pass from one cell to the next. To activate a neuron, a high enough activating signal or 'action potential' must be reached. However, the accepted view of signal transmission assumes that the great majority of synapses are too weak to activate neurons. This means that often simultaneous inputs from many neurons are required to trigger a single neuron's activation. However, such coordination is likely unreliable as neurons can react differently to the same stimulus depending on the circumstances. An alternative way of transmitting signals has been reported in turtle brains, where impulses from a single neuron can trigger activity across a network of connections. Furthermore, these responses are reliably repeatable, activating the same neurons in the same order. Riquelme et al. set out to understand the mechanism that underlies this type of neuron activation using a mathematical model based on data from the turtle brain. These data showed that the neural network in the turtle's brain had many weak synapses but also a few, rare, strong synapses. Simulating this neural network showed that those rare, strong synapses promote the signal's reliability by providing a consistent route for the signal to travel through the network. The numerous weak synapses, on the other hand, have a regulatory role in providing flexibility to how the activation spreads. This combination of strong and weak connections produces a system that can reliably promote or stop the signal flow depending on the context. Riquelme et al.'s work describes a potential mechanism for how signals might travel reliably through neural networks in the brain, based on data from turtles. Experimental work will need to address whether strong connections play a similar role in other animal species, including humans. In the future, these results may be used as the basis to design new systems for artificial intelligence, building on the success of neural networks.

JUNO Project: Deployment and Validation of a Low-Cost Cloud-Based Robotic Platform for Reliable Smart Navigation and Natural Interaction with Humans in an Elderly Institution.

This paper describes the main results of the JUNO project, a proof of concept developed in the Region of Murcia in Spain, where a smart assistant robot with capabilities for smart navigation and natural human interaction has been developed and deployed, and it is being validated in an elderly institution with real elderly users. The robot is focused on helping people carry out cognitive stimulation exercises and other entertainment activities since it can detect and recognize people, safely navigate through the residence, and acquire information about attention while users are doing the mentioned exercises. All the information could be shared through the Cloud, if needed, and health professionals, caregivers and relatives could access such information by considering the highest standards of privacy required in these environments. Several tests have been performed to validate the system, which combines classic techniques and new Deep Learning-based methods to carry out the requested tasks, including semantic navigation, face detection and recognition, speech to text and text to speech translation, and natural language processing, working both in a local and Cloud-based environment, obtaining an economically affordable system. The paper also discusses the limitations of the platform and proposes several solutions to the detected drawbacks in this kind of complex environment, where the fragility of users should be also considered.

Influencia de la seropositividad contra adenovirus-36 sobre riesgo de obesidad y resistencia a la insulina en población infanto-juvenil de la Región de la Araucanía / Influence of adenovirus 36 seropositivity on the risk of obesity and insulin resistance in a population of children and adolescents from the Región de la Araucanía

La infección previa por el adenovirus-36 (Ad-36) se ha asociado con el proceso adipogénico y el control glicémico en modelos experimentales de cultivos celulares y animales. En humanos, la presencia de anticuerpos contra Ad-36 ha mostrado aumentar el riesgo de obesidad y, paradójicamente, mejorar el control glicémico en diferentes poblaciones. Se evaluó la influencia de la seropositividad contra Ad-36 sobre riesgo de obesidad, el perfil lipídico y glicémico en una población de niños en edad escolar. Métodos: Doscientos ocho individuos de entre 9 y 13 años se agruparon según estado nutricional como normopeso (IMC z-score de -1 a +1), con sobrepeso (IMC z-score de +1 a +2) y con obesidad (IMC z-score > +3). Se evaluaron medidas antropométricas, desarrollo puberal según Tanner y parámetros bioquímicos (perfil lipídico, glucemia e insulina) y la seropositividad contra Ad-36. Se determinó la resistencia a la insulina (RI) según criterio para la población infantil chilena. La seropositividad contra Ad-36 se determinó mediante ELISA. Resultados: Hubo una alta prevalencia de sobrepeso/obesidad en la población de estudio. La seropositividad contra Ad-36 fue del 5,4% en el grupo total, pero no se observó una asociación con el estado nutricional. No se encontró correlación entre la seropositividad contra Ad-36 y los parámetros del perfil lipídico. La insulina y la HOMA-RI fueron significativamente más bajas en el grupo Ad-36 (+) (p<0,001), no habiendo sido reportados casos de RI en el grupo Ad-36 (+) en nuestra población. Conclusiones: Nuestros resultados sugieren que la infección previa por el adenovirus-36 afecta la secreción de insulina y la resistencia a la insulina, como se ha descrito anteriormente, sin embargo, no se observa correlación con el desarrollo de la obesidad infantil en la población pediátrica del sur de Chile.

Previous infection with Adenovirus-36 (Ad-36) has been associated with adipogenic process and glycemic control in experimental models of cell culture and animals. In humans, the presence of antibodies against Ad-36 has been shown to increase the risk of obesity and, paradoxically, improve glycemic control in different populations. The influence of Ad-36 seropositivity on obesity risk, lipid and glycemic profile was evaluated in a population of school-age children. Methods: Two hundred eight individuals aged 9 to 13 years were grouped according to their nutritional status as normal weight (BMI z-score from -1 to +1), overweight (BMI z-score from +1 to +2) or obese (BMI z-score from -1 to +1). z-score > +3). Anthropometric measurements, pubertal development according to Tanner stage, biochemical parameters (lipid profile, glycemia and insulin) and seropositivity against Ad-36 were evaluated. Insulin resistance (IR) was determined according to criteria for the Chilean child population. Seropositivity against Ad-36 was determined by ELISA. Results: There was a high prevalence of overweight/obesity in the study population. Seropositivity against Ad-36 was 5.4% in the total group, but no association with nutritional status was observed. No correlation was found between Ad-36 seropositivity and lipid profile parameters. Insulin and HOMA-RI were significantly lower in the Ad-36 (+) group (p<0.001), and no cases of RI were reported in the Ad-36 (+) group in our population. Conclusions: Our results suggest that previous adenovirus-36 infection affects insulin secretion and insulin resistance, as previously described, however, no correlation is observed with the development of childhood obesity in the pediatric population. from southern Chile.

Irriman Platform: Enhancing Farming Sustainability through Cloud Computing Techniques for Irrigation Management.

Crop sustainability is essential for balancing economic development and environmental care, mainly in strong and very competitive regions in the agri-food sector, such as the Region of Murcia in Spain, considered to be the orchard of Europe, despite being a semi-arid area with an important scarcity of fresh water. In this region, farmers apply efficient techniques to minimize supplies and maximize quality and productivity; however, the effects of climate change and the degradation of significant natural environments, such as, the "Mar Menor", the most extent saltwater lagoon of Europe, threatened by resources overexploitation, lead to the search of even better irrigation management techniques to avoid certain effects which could damage the quaternary aquifer connected to such lagoon. This paper describes the Irriman Platform, a system based on Cloud Computing techniques, which includes low-cost wireless data loggers, capable of acquiring data from a wide range of agronomic sensors, and a novel software architecture for safely storing and processing such information, making crop monitoring and irrigation management easier. The proposed platform helps agronomists to optimize irrigation procedures through a usable web-based tool which allows them to elaborate irrigation plans and to evaluate their effectiveness over crops. The system has been deployed in a large number of representative crops, located along near 50,000 ha of the surface, during several phenological cycles. Results demonstrate that the system enables crop monitoring and irrigation optimization, and makes interaction between farmers and agronomists easier.

Relación de la actividad física medida objetivamente con dislipidemias y factores de riesgo cardiovascular en escolares de la Región de La Araucanía / Relationship of objectively measured physical activity with dyslipidemias and cardiovascular risk factors in schoolchildren from Región de La Araucanía cases

INTRODUCCIÓN: Las dislipidemias favorecen la formación precoz de placas ateroscleróticas, aumentando el riesgo de enfermedades cardiovasculares (ECVs). La Actividad Física (AF) es un factor protector de ECVs, por lo que el objetivo de este trabajo fue evaluar la asociación entre AF medida objetivamente y dislipidemias en población pediátrica. METODOLOGÍA: La AF fue evaluada en 159 niños (9-13 años) de la Región de La Araucanía a través de acelerometría (ActiGraph GT3X+). Por este medio se estimó el porcentaje de AF moderada a vigorosa (AFMV) y el de conducta sedentaria (CS). Sujetos con ≥60 min de AFMV se consideraron físicamente activos según recomendación de la Organización Mundial de la Salud (OMS). Individuos con %CS>75° percentil fueron considerados sedentarios. El perfil lipídico fue determinado usando métodos convencionales. Fueron calculados índices de aterogenicidad TG/cHDL e índice de aterogenicidad del plasma (IAP). RESULTADOS: 37,1% presentó dislipidemia, 8% hipercolesterolemia, 19,5% hipertrigliceridemia, 6,3% cLDL elevado y 25,2% cHDL disminuido. Solo un 9,4% fueron considerados físicamente activos de acuerdo a la recomendación de la OMS. En los sujetos físicamente activos no hubo caso de dislipidemias (p= 0,032) y tampoco bajos niveles de cHDL (p= 0,013). El %AFMV estaba reducido en sujetos con cHDL bajo y se correlacionó positivamente con HDL-c (r= 0,157, p=0,048). Además, el %AFMV se correlacionó con menores valores de TG/cHDL (r= -0,193, p=0,015) e IAP (r= -0,214, p=0,006). Si bien el comportamiento sedentario no estuvo asociado con riesgo de dislipidemias, el %CS se correlacionó positivamente con niveles de glucosa (r= 0,159, p=0,044) y HOMA-IR (r= 0,178, p=0,037) y negativamente con Quicki (r= -0,160, p=0,044). CONCLUSIONES: Los hallazgos sugieren que la AF se correlaciona a menor frecuencia de dislipidemias y la práctica de AFMV aumentaría los valores de HDL-c y reduciría los índices aterogénicos, por lo que promoverla puede significar disminuir el riesgo de ECVs en nuestra población. Además, la CS se relaciona con un aumento en valores de glucosa e índices de resistencia insulínica en escolares de la Región de La Araucanía.

Dyslipidemias cause early formation of atherosclerotic plaque, increasing the risk of cardiovascular diseases (CVD). Physical Activity (PA) is a protective factor against CVDs. The aim of this study is to evaluate the association between objectively measured PA with dyslipidemias in a pediatric population. METHOD: The PA was evaluated in 159 children (9-13 years old) from Región de La Araucanía using accelerometry (ActiGraph GT3X +). The percentage of moderate to vigorous PA (MVPA) and sedentary behavior (SB) were estimated. Subjects with ≥60 min of MVPA were considered physically active according to the recommendation of the World Health Organization (WHO). Individuals with %SB >75th percentile were sedentary. The lipid profile was determined using conventional methods. TG/HDL-C ratio and atherogenic index of plasma (AIP) were calculated. RESULTS: 37.1% presented dyslipidemia, 8% hypercholesterolemia, 19.5% hypertriglyceridemia, 6.3% elevated LDL-C and 25.2% decreased HDL-C. Only 9.4% were physically active according to the WHO recommendation. In physically active subjects where no cases of dyslipidemias (p =0.032) and no low HDL-C (p = 0.013). The %MVPA was reduced in subjects with low HDL-C and positively correlated with HDL-c (r = 0.157, p = 0.048). In addition, %MVPA was correlated with lower TG / HDL-C values (r = -0.193, p = 0.015) and AIP (r = -0.214, p = 0.006). SB was not associated with risk of dyslipidemia, % SB was positively correlated with glucose levels (r = 0.159, p = 0.044) and HOMA-IR (r = 0.178, p = 0.037) and negatively with Quicki (r = -0.160, p = 0.044). CONCLUSIONS: Our results suggested that PA is it correlates to a lower frequency of dyslipidemia and the practice of MVPA would increase HDL-c values and reduce atherogenic index, promoting it may been reducing the risk of CVDs in our population. In addition, the SB is related to an increase in glucose values and insulin resistance index in schoolchildren in Región de La Araucanía.

IoT Architecture for Smart Control of an Exoskeleton Robot in Rehabilitation by Using a Natural User Interface Based on Gestures.

This paper describes a system for allowing a therapist to record specific motions, as a part of a rehabilitation program, mainly aimed at the elderly people, by using a Natural User Interface based on gestures. Motions are sent to an exoskeleton robot which reproduces them in the patient's lower limbs. The proposed system is an early prototype implemented as a set of interconnected components, which run independently and remotely, under a distributed software architecture. Such prototype has been properly validated through different tests in a controlled environment. The obtained results and a discussion about benefits and drawbacks are also presented, together with preliminary ideas about future research for overcoming such drawbacks and transforming the prototype into a functional system to be tested in a real scenario with real patients.

Investigating functional changes in the brain to intermittently induced auditory illusions and its relevance to chronic tinnitus.

Several studies have demonstrated the neural correlates of chronic tinnitus. However, we still do not understand what happens in the acute phase. Past studies have established Zwicker tone (ZT) illusions as a good human model for acute tinnitus. ZT illusions are perceived following the presentation of a notched noise stimulus, that is, broadband noise with a narrow band-stop filter (notch). In the current study, we compared the neural correlates of the reliable perception of a ZT illusion to that which is not. We observed changes in evoked and total theta power in wide-spread regions of the brain particularly in the temporal-parietal junction, pregenual anterior cingulate cortex/ventromedial prefrontal cortex (pgACC/vmPFC), parahippocampus during perception of the ZT illusion. Furthermore, we observe that increased theta power significantly predicts a gradual positive change in the intensity of the ZT illusion. Such changes may suggest a malfunction of the sensory gating system that enables habituation to redundant stimuli and suppresses hyperactivity. It could also suggest a successful retrieval of the memory of the missing frequencies, resulting in their conscious perception indicating the role of higher-order processing in the mechanism of action of ZT illusions. To establish a more concrete relationship between ZT illusion and chronic tinnitus, future longitudinal studies following up a much larger sample of participants who reliably perceive a ZT illusion to see if they develop tinnitus at a later stage is essential. This could inform us if the ZT illusion may be a precursor to chronic tinnitus.

Crisis hipercalcémica como primera manifestación del hiperparatiroidismo primario en la adolescencia / Hypercalcemic crisis as first manifestation of primary hyperparathyroidism in adolescence

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Utilidad de la reconstrucción tridimensional mediante tomografía computarizada en el bocio multinodular intratorácico con afectación traqueal / Utility of three-dimensional reconstruction through computed tomography in intrathoracic multinodular goiter with tracheal involvement

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Elevated basal calcitonin levels in a patient with a hurthle-cell carcinoma of the thyroid and neuroendocrine differentiation: report of a case.

A thyroid nodule with elevated plasma levels of calcitonin is usually suggestive of a medullary thyroid carcinoma (MTC); however, thyroid and extrathyroid conditions have been reported with elevated plasma calcitonin levels in the absence of MTC. We report the case of a patient with a thyroid nodule and an elevated basal plasma calcitonin level of 315 pg/ml (normal value <100 pg/ml) who underwent a left hemithyroidectomy. Interestingly, histopathological examination revealed a Hurthle-cell carcinoma with positive neuroendocrine (NE) markers such as calcitonin and synapthophysin, but not with chromogranin staining. Thus, we discuss the phenomenon of non-NE tumors showing positivity for NE markers.

Estudio multivariable de los factores de riesgo para desarrollar complicaciones en la cirugía del bocio multinodular / Multivariate study of risk fators for developing complications after multinodular goiter surgery

Introducción. El bocio multinodular (BM) supone un alto volumen de pacientes en los servicios de cirugía endocrina. Sin embargo, los factores de riesgo de morbilidad tras la cirugía no han sido investigados sistemáticamente. El objetivo es analizar, mediante un análisis estadístico multivariable, los resultados quirúrgicos, en cuanto a morbimortalidad, para poder determinar los factores de riesgo de la cirugía del BM. Pacientes y método. Se han revisado retrospectivamente 672 BM intervenidos. Las variables analizadas fueron la edad, el sexo, la cirugía previa, el tiempo de evolución, la sintomatología, el componente intratorácico, la gradación cervical del bocio, la duración de la cirugía, la experiencia del cirujano, la técnica quirúrgica, la identificación de estructuras, el carcinoma tiroideo asociado y el peso de la pieza tiroidea. Se aplicaron el test de la ÷2 y el de la t de Student, así como un análisis de regresión logística. Resultados. El índice de morbilidad fue del 22% (n = 147), la mayoría correspondiente a hipoparatiroidismos y lesiones recurrenciales transitorias. Los factores de riesgo para desarrollar estas complicaciones fueron la presencia de sintomatología (p = 0,0131), el hipertiroidismo (p = 0,0333), la sintomatologíacompresiva (p = 0,0158), la gradación clínica del bocio (p = 0,0482), la técnica quirúrgica realizada (p < 0,00001) y el peso del tiroides (p = 0,0302); como factores de riesgo independiente persistieron la técnica quirúrgica, el hipertiroidismo y la gradación del bocio. El índice de complicaciones definitivas fue del 2,2% (n = 15), que corresponden a 6 hipoparatiroidismos (0,9%) y 10 lesiones recurrenciales (1,5%). El factor de riesgo para su desarrollo es el hipertiroidismo (p = 0,0037; riesgo relativo [RR] = 2,8). Conclusiones. El principal factor de riesgo independiente para el desarrollo de complicaciones en la cirugía del BM es el hipertiroidismo (AU)

Introduction. Multinodular goiter (MG) accounts for a large volume of procedures performed in endocrine surgery departments. However, risk factors for postoperative complications have not been systematically investigated. The aim of the present study was to evaluate surgical outcomes in terms of morbidity and mortality through multivariate statistical analysis with a view to determining risk factors in MG surgery. Patients and method. A total of 672 patients who underwent surgery for MG were retrospectively reviewed. The variables analyzed were age, sex, prior surgery, disease duration, symptomatology, intrathoracic component, the surgeon’s experience, surgical technique, identification of structures, associated thyroid carcinoma and thyroid specimen weight. The chi-squared test, Student’s t-test and logistic regression analysis were performed. Results. Morbidity was 22% (n = 147) and mostly corresponded to hypoparathyroidisms and transitory recurrent lesions. Risk factors for developing these complications were symptomatic disease (p = 0.0131), hyperthyroidism (p = 0.0333), compressive symptoms (p = 0.0158), clinical grade of the goiter (p = 0.0482), surgical technique (p < 0.00001) and thyroid weight (p = 0.0302). Independent risk factors were surgical technique, hyperthyroidism and goiter grade. The definitive complication rate was 2.2% (n = 15), corresponding to six hypoparathyroidisms (0.9%) and 10 recurrent lesions (1.5%). The risk factor for their development was hyperthyroidism (p = 0.0037; RR = 2.8). Conclusions. The main independent risk factor for complications after MG surgery is hyperthyroidism (AU)