Publications by authors named "Maria P Guarino"

Diabetes is a disease that affects millions of people in the world and its early screening prevents serious health problems, also providing relief in the demand for healthcare services. In the search for methods to support early diagnosis, this article introduces a novel prediabetes risk classification algorithm (PRCA) for type-2 diabetes mellitus (T2DM), utilizing the chemosensitivity of carotid bodies (CB) and K-means clustering technique from the field of machine learning. Heart rate (HR) and respiratory rate (RR) data from eight volunteers with prediabetes and 25 without prediabetes were analyzed.

View Article and Find Full Text PDF

Obesity is a chronic, complex and multi-factorial condition with an increasing prevalence worldwide. Irregular eating schedules might be a contributing factor to these numbers through the dysregulation of the circadian system. Time-restricted eating (TRE), an approach that limits eating windows, has been studied as a strategy to treat obesity, aligning eating occasions with metabolic circadian rhythms.

View Article and Find Full Text PDF

Bioelectronic medicine are an emerging class of treatments aiming to modulate body nervous activity to correct pathological conditions and restore health. Recently, it was shown that the high frequency electrical neuromodulation of the carotid sinus nerve (CSN), a small branch of the glossopharyngeal nerve that connects the carotid body (CB) to the brain, restores metabolic function in type 2 diabetes (T2D) animal models highlighting its potential as a new therapeutic modality to treat metabolic diseases in humans. In this manuscript, we review the current knowledge supporting the use of neuromodulation of the CSN to treat T2D and discuss the future perspectives for its clinical application.

View Article and Find Full Text PDF

Background: Promoting healthy eating in children is key to preventing chronic diseases, and vegetable consumption is notably lower than recommended in this population. Among the interventions tested, gamification has shown promise in promoting familiarization, increasing knowledge, and potentially increasing vegetable intake.

Objective: This pilot study aimed first to translate the digital game "Veggies4myHeart" into French and to assess its influence on young children's preferences and willingness to taste vegetables when combined with repeated tasting and education.

View Article and Find Full Text PDF

Obesity is a worldwide epidemic being the main cause of cardiovascular, metabolic disturbances and chronic pulmonary diseases. The increase in body weight may affect the respiratory system due to fat deposition and systemic inflammation. Herein, we evaluated the sex differences in the impact of obesity and high abdominal circumference on basal ventilation.

View Article and Find Full Text PDF

Background: The prevalence of obesity continues to rise, and although this is a complex disease, the screening is made simply with the value of the Body Mass Index. This index only considers weight and height, being limited in portraying the multiple existing obesity phenotypes. The characterization of the chronotype and circadian system as an innovative phenotype of a patient's form of obesity is gaining increasing importance for the development of novel and pinpointed nutritional interventions.

View Article and Find Full Text PDF

Metabolic diseases are a global rising health burden, mainly due to the deleterious interaction of current lifestyles with the underlying biology of these diseases. Daily habits and behaviors, such as diet, sleep, and physical exercise impact the whole-body circadian system through the synchronization of the peripheral body clocks that contribute to metabolic homeostasis. The disruption of this system may promote the development of metabolic diseases, including obesity and diabetes, emphasizing the importance of assessing and monitoring variables that affect circadian rhythms.

View Article and Find Full Text PDF

The oral glucose tolerance test (OGTT) is recommended for assessing abnormalities in glucose homeostasis. Recognised as the gold standard test for diagnosing diabetes, the OGTT provides useful information about glucose tolerance. However, it does not replicate the process of absorption and digestion of complex foods, such as that which occurs with a mixed meal tolerance test (MMTT), an alternative that is still not well explored in the diagnosis of metabolic alterations.

View Article and Find Full Text PDF

Chronic carotid sinus nerve (CSN) electrical modulation through kilohertz frequency alternating current improves metabolic control in rat models of type 2 diabetes, underpinning the potential of bioelectronic modulation of the CSN as a therapeutic modality for metabolic diseases in humans. The CSN carries sensory information from the carotid bodies, peripheral chemoreceptor organs that respond to changes in blood biochemical modifications such as hypoxia, hypercapnia, acidosis, and hyperinsulinemia. In addition, the CSN also delivers information from carotid sinus baroreceptors-mechanoreceptor sensory neurons directly involved in the control of blood pressure-to the central nervous system.

View Article and Find Full Text PDF

Objective: To test the efficacy of three nutrition education strategies on the intake of different vegetables in preschool children.

Design: This is an experimental study conducted in four Portuguese preschools. The intervention consisted of 20-min educational sessions, once a week, for 5 weeks, with one of the following randomised educational strategies: Portuguese Food Wheel Guide (control), digital game, storybook, storybook and reward (stickers).

View Article and Find Full Text PDF

Introduction: Early screening of metabolic diseases is crucial since continued undiagnostic places an ever-increasing burden on healthcare systems. Recent studies suggest a link between overactivated carotid bodies (CB) and the genesis of type 2 diabetes mellitus. The non-invasive assessment of CB activity by measuring ventilatory, cardiac and metabolic responses to challenge tests may have predictive value for metabolic diseases; however, there are no commercially available devices that assess CB activity.

View Article and Find Full Text PDF

Objective: The carotid bodies (CBs) are peripheral chemoreceptor organs classically described as being O2 sensors, which are increasingly emerging as core players in metabolic control. Herein we evaluated CB activity in prediabetes patients and determined its correlation with dysmetabolism clinical features.

Design And Methods: Prediabetes patients were recruited at the Cardiology Service, Hospital Santa Marta, Centro Hospitalar Lisboa Central, EPE (CHLC-EPE).

View Article and Find Full Text PDF

Type 2 Diabetes (T2DM) is a chronic disease which corresponds to 90% of the worldwide cases of diabetes, mainly due to epigenetic factors such as unhealthy lifestyles. First line therapeutic approaches are based on lifestyle changes, most of the time complemented with medication mostly associated with several side effects and high costs. As a result, the scientific community is constantly working for the discovery and development of natural therapeutic strategies that provide lower financial impact and minimize side effects.

View Article and Find Full Text PDF

Animal experimentation has a long history in the study of metabolic syndrome-related disorders. However, no consensus exists on the best models to study these syndromes. Knowing that different diets can precipitate different metabolic disease phenotypes, herein we characterized several hypercaloric rat models of obesity and type 2 diabetes, comparing each with a genetic model, with the aim of identifying the most appropriate model of metabolic disease.

View Article and Find Full Text PDF

The carotid body is now looked at as a multipurpose sensor for blood gases, blood pH, and several hormones. The matter of glucose sensing by the carotid body has been debated for several years in the literature, and these days there is a consensus that carotid body activity is modified by metabolic factors that contribute to glucose homeostasis. However, the sensing ability for glucose is still being pondered: are the carotid bodies low glucose sensors or, in contrast, are they overresponsive in high-glucose conditions? Herein, we debate the glucose and insulin sensing capabilities of the carotid body as key early events in the overactivation of the carotid body, which is increasingly recognized as an important feature of metabolic diseases.

View Article and Find Full Text PDF

Aims/hypothesis: A new class of treatments termed bioelectronic medicines are now emerging that aim to target individual nerve fibres or specific brain circuits in pathological conditions to repair lost function and reinstate a healthy balance. Carotid sinus nerve (CSN) denervation has been shown to improve glucose homeostasis in insulin-resistant and glucose-intolerant rats; however, these positive effects from surgery appear to diminish over time and are heavily caveated by the severe adverse effects associated with permanent loss of chemosensory function. Herein we characterise the ability of a novel bioelectronic application, classified as kilohertz frequency alternating current (KHFAC) modulation, to suppress neural signals within the CSN of rodents.

View Article and Find Full Text PDF

Key Points: Leptin plays a role in the control of breathing, acting mainly on central nervous system; however, leptin receptors have been recently shown to be expressed in the carotid body (CB), and this finding suggests a physiological role for leptin in the regulation of CB function. Leptin increases minute ventilation in both basal and hypoxic conditions in rats. It increases the frequency of carotid sinus nerve discharge in basal conditions, as well as the release of adenosine from the CB.

View Article and Find Full Text PDF

Aims/hypothesis: We recently described that carotid body (CB) over-activation is involved in the aetiology of insulin resistance and arterial hypertension in animal models of the metabolic syndrome. Additionally, we have demonstrated that CB activity is increased in animal models of insulin resistance, and that carotid sinus nerve (CSN) resection prevents the development of insulin resistance and arterial hypertension induced by high-energy diets. Here, we tested whether the functional abolition of CB by CSN transection would reverse pre-established insulin resistance, dyslipidaemia, obesity, autonomic dysfunction and hypertension in animal models of the metabolic syndrome.

View Article and Find Full Text PDF

Metabolic diseases affect millions of individuals across the world and represent a group of chronic diseases of very high prevalence and relatively low therapeutic success, making them suitable candidates for pathophysiological studies. The sympathetic nervous system (SNS) contributes to the regulation of energy balance and energy expenditure both in physiological and pathological states. For instance, drugs that stimulate sympathetic activity decrease food intake, increase resting metabolic rate and increase the thermogenic response to food, while pharmacological blockade of the SNS has opposite effects.

View Article and Find Full Text PDF

Caffeine, a non-selective adenosine antagonist, has distinct effects on insulin sensitivity when applied acutely or chronically. Herein, we investigated the involvement of adenosine receptors on insulin resistance induced by single-dose caffeine administration. Additionally, the mechanism behind adenosine receptor-mediated caffeine effects in skeletal muscle was assessed.

View Article and Find Full Text PDF

The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation.

View Article and Find Full Text PDF

Increased sympathetic activity is a well-known pathophysiological mechanism in insulin resistance (IR) and hypertension (HT). The carotid bodies (CB) are peripheral chemoreceptors that classically respond to hypoxia by increasing chemosensory activity in the carotid sinus nerve (CSN), causing hyperventilation and activation of the sympathoadrenal system. Besides its role in the control of ventilation, the CB has been proposed as a glucose sensor implicated in the control of energy homeostasis.

View Article and Find Full Text PDF

Background: Reduced plasma nitrate (NO(x)) levels and increased urinary norepinephrine (U-NE) levels have been described in severe obstructive sleep apnea (OSA), and are reverted by continuous positive airway pressure (CPAP). The effect of CPAP on these biomarkers in mild-moderate OSA is not well understood. The aim of this study was to compare NO(x) and U-NE levels and blood pressure (BP) between male patients with mild-moderate and severe OSA and determine the impact of 1 month of CPAP therapy on these parameters.

View Article and Find Full Text PDF

We compared the effects of two different anaesthetics, sodium pentobarbital (65 mg/kg) and ketamine (30 mg/kg) plus xylazine (4 mg/kg) (KX) on insulin sensitivity, fasting glycaemia, insulinaemia and free fatty acids (FFA). Four groups of Wistar rats were used: KX group (n=6), pentobarbital group (n=6), high-sucrose diet group (n=6) and the conscious group (n=6). The insulin tolerance test (ITT) was used to measure insulin sensitivity, and metabolic biomarkers were determined using commercial kits.

View Article and Find Full Text PDF

The role of caffeine consumption on insulin action is still under debate. The hypothesis that chronic caffeine intake reverses aging-induced insulin resistance in the rat was tested in this work. The mechanism by which caffeine restores insulin sensitivity was also investigated.

View Article and Find Full Text PDF