Facultad de Farmacia

Context: The melanocortin-4 receptor gene (MC4R) is associated with a higher risk of obesity by the presence of the C allele in rs17782313, but the mechanisms are not clear. Objective: The present systematic review and meta-analysis aimed to explore the association between the different genotypes of MC4R rs17782313 and energy intake and appetite. Data Sources: A literature search was conducted up to June 2023 in PubMed, Scopus, Web of Science, and Cochrane Collaboration databases, following PRISMA guidelines. Data Extraction: Inclusion criteria were studies in humans measuring energy intake, appetite, or satiety in all ages and physiological conditions. Studies dealing solely with body mass index were excluded. Twenty-one articles representing 48 560 participants were included in the meta-analysis. Data Analysis: According to the NHLBI (National Heart, Lung, and Blood Institute) quality-assessment criteria, all case-control studies and 6 out of 17 cohort and cross-sectional studies were classified as “good,” while the rest scored as “fair.” Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in a (CTþCC) vs TT dominant model, and both random-effects and fixed-effects models were used. A statistically significant association between the presence of the C allele and increased appetite was found (OR ¼ 1.25; 95% CI: 1.01–1.49; P ¼ .038) using the fixed-effects model, but the random-effects model proved nonsignificant. However, no association with energy intake was found. None of the variables con sidered (sample size, year of publication, sex, age group, type of population, origin, and quality) were identified as effect modifiers, and no publication biases were found after subgroup and meta-regression analyses. Conclusion: To our knowl edge, this is the first systematic review and meta-analysis that has analyzed the association between rs17782313 of MC4R and energy intake and appetite. Identifying people genetically predisposed to increased appetite may be of great interest, not only to prevent obesity in younger populations but also to avoid mal nutrition in elderly persons. This paper is part of the Nutrition Reviews Special Collection on Precision Nutrition.

Syrian hamsters undergo a reversible hyperphosphorylation of protein τ during hibernation, providing a unique natural model that may unveil the physiological mechanisms behind this critical process involved in the development of Alzheimer’s disease and other tauopathies. The hibernation cycle of these animals fluctuates between a pair of stages: 3–4 days of torpor bouts interspersed with periods of euthermia called arousals that last several hours. In this study, we investigated for the first time the metabolic changes in brain tissue during hibernation. A total of 337 metabolites showed statistically significant differences during hibernation. Based on these metabolites, several pathways were found to be significantly regulated and, therefore, play a key role in the regulation of hibernation processes. The increase in the levels of ceramides containing more than 20 C atoms was found in torpor animals, reflecting a higher activity of CerS2 during hibernation, linked to neurofibrillary tangle generation and structural changes in the Golgi apparatus. Our results open up the debate about the possible significance of some metabolites during hibernation, which may possibly be related to τ phosphorylation and dephosphorylation events. In general, this study may provide insights into novel neuroprotective agents because the alterations described throughout the hibernation process are reversible.

The increasing prevalence of overweight and obesity has become an epidemic public health problem worldwide. In the last years, several investigations have suggested that water intake and retention could have important implications for both weight management and body composition. However, there is a lack of information about this issue globally, and mainly specifically in Spain. Thus, the aim of this study was to analyze the association between hydration status and body composition in a sample of healthy Spanish adults. The study involved 358 subjects, aged 18–39 years. The recently validated “hydration status questionnaire” was used to assess their water intake, elimination, and balance. Anthropometric measurements were performed according to the recommendations of the International Standards for Anthropometric Assessment (ISAK). Body composition variables were acquired by bioelectrical impedance analysis. Differences in anthropometric and body composition variables were assessed through the ANOVA test and considered significant at p < 0.05. Fluid intake was correlated with body water content. Inverse associations between water consumption, normalized by weight, with body weight, body fat mass, and waist circumference were found. Moreover, according to water balance, significant differences in body water content in females were observed. In conclusion, higher fluid intake seems to be related with a healthier body composition. Therefore, the improvement of water intake and water balance could be useful for overweight and obesity prevention, although further studies are needed to confirm the present findings.

At present, obesity and overweight are major public health concerns. Their classical determinants do not sufficiently explain the current situation and it is urgent to investigate other possible causes. In recent years, it has been suggested that water intake could have important implications for weight management. Thus, the aim of this study was to examine the effect of hydration status on body weight and composition in healthy adolescents from Spain. The study involved 372 subjects, aged 12–18 years. Water intake was assessed through the validated “hydration status questionnaire adolescent young”. Anthropometric measurements were performed according to the recommendations of the International Standards for Anthropometric Assessment (ISAK) and body composition was estimated by bioelectrical impedance analysis. Water intake normalized by body weight was positively correlated with body water content (boys (B): r = 0.316, p = 0.000; girls (G): r = 0.245, p = 0.000) and inversely with body mass index (BMI) (B: r = −0.515, p = 0.000; G: r = −0.385, p =0.000) and fat body mass (B: r = −0.306, p = 0.000; G: r = −0.250, p = 0.001). Moreover, according to BMI, overweight/obese individuals consumed less water than normal weight ones. In conclusion, higher water balance and intake seems to be related with a healthier body composition.

Noise-induced hearing loss is the most frequent and preventable occupational disease. Aviation pilots are a vulnerable population, as they spend many hours exposed to noise pollution in their working environment. Different studies suggest that certain dietary compounds may play a key role in the etiology and prevention of this pathology. We aimed to study the relationship linking auditory function, dietary intake, and some serum biomarkers in pilots, exposed to noise in the work environment. A total of 235 pilots, who undergo a periodic medical examination at the Centro de Instrucción de Medicina Aeroespacial (Madrid, SPAIN), were evaluated. Auditory function was assessed by tonal audiometry. Energy and nutrient intakes were estimated by 24 h recall (DIALTM program). Serum homocysteine (Hcy) was determined in a Cobas 6000TM multi-analyzer while folate, vitamin B12, and D were analyzed in a Cobas 411TM. The prevalence of hearing loss (HL) was 64.3%. HL was significantly related to age (r = 0.588, p 0.001) and flight hours (r = 0.283, p 0.001). A multiple linear regression model was used to assess the relationship among HL, flight hours, serum folate, and Hcy serum levels. HL was significantly (p < 0.050) associated with flight hours ( = 0.246), serum folate ( = 􀀀0.143), and serum Hcy ( = 0.227). Nutritional interventions would be of great interest to monitor and slow down the HL progression in populations exposed to noise pollution in their workplace.

Recombinant human growth hormone (rhGH) therapy is the primary treatment for children born small for gestational age (SGA) who fail to show spontaneous catch-up growth by two or four years. While its effects on white adipose tissue are well-documented, this pilot study aimed to investigate its impact on the lipidome and the thermogenic and endocrine activities of brown adipose tissue (BAT) in SGA children following rhGH treatment. The study involved 11 SGA children divided into two groups: a) SGA children who were not treated with rhGH (n=4) and b) SGA children who received rhGH treatment with Saizen® (n=7). This second group of seven SGA children was followed for 12 months after initiating rhGH treatment. Interventions included 12-hour fasting blood extraction and infrared thermography at baseline and 3 and 12 months post-treatment. Five appropriate-for-gestational-age (AGA) children served as controls. Exclusion criteria included endocrinological, genetic, or chronic diseases. Untargeted lipidomics analysis was performed using liquid chromatography-mass spectrometry (LC-MS), and serum biomarker levels were measured using ELISA assays. Serum lipidomic analysis revealed that free fatty acids (FFAs) increased to levels close to those of the AGA group after three months of rhGH administration, including polyunsaturated fatty acids, correlating with reduced leptin levels. Elevated levels of 1a,1b-dihomo-PGJ2 and adrenic acid suggested potential aging markers. rhGH treatment also significantly reduced meteorin-like (METRNL) and monocyte chemoattractant protein-1 (MCP1) serum levels to control levels. rhGH influences the serum lipidome, promoting changes in maturation and metabolism. Further research is required to clarify the direct effects of rhGH on specific lipid species and batokines, potentially addressing metabolic disturbances linked to obesity and aging.

We present results for organic liquids modeled as linear rods with an embedded point dipole shifted from the geometrical center. Previously, we have obtained results for the vapor−liquid equilibrium (VLE) of similar systems with centered point dipoles. Our results included both models and applications to real systems. Results presented here are based on a previous work (Phys. Rev. E2003, 68, 021201) on the structural properties of these systems where relevant results about the appearance of dimers were found. Now, we have also performed systematic simulations on these systems to calculate the VLE of models with different aspect ratios, dipole shifts, and dipole strengths using the Gibbs ensemble Monte Carlo (GEMC) to calculate equilibrium densities and vapor pressure at each temperature. The applications considered here include some important substances such as 1-amines, acetonitrile, and 1-alcohols whose intermolecular parameters were fitted from our model simulations. Furthermore, we have used quantum chemistry calculations to obtain a reliable charge distribution, and we have applied our model to predict the vapor pressure of α,ω-diols where experimental results are rather scarce. Our results show a general improvement of the agreement between experiment and models compared to centered dipole models previously used. Results for amines are particularly remarkable.

Gibbs ensemble Monte Carlo simulations are performed to obtain the vapour–liquid equilibrium of oblate-like fluids interacting through the Kihara intermolecular potential. Results confirm the validity of a perturbation theory for Kihara fluids, whose accuracy for prolate fluids was tested some years ago. As in the case of hard ellipsoids, the symmetry of the phase diagram of oblate and prolate models is analysed. An interesting relation of Boyle temperature and critical parameters with molecular volume is found for the considered models. As a particular application, this relation allows the prediction of some thermodynamic properties of a new promising biofuel 2,5dimethylfuran.

Simulation results for a system comprising a square well plus either a point dipole or a point quadrupole are presented. The properties obtained are the vapour–liquid equilibrium densities and the critical properties. Critical densities are not very sensitive to the values of dipole or quadrupole, while critical temperatures increase significantly when the multipole strength rises. A comparison with a perturbation theory for multipolar square-well systems is presented. Overall agreement between simulated and theoretical values is good when comparison is restricted to quadrupoles or dipoles corresponding to the most relevant real polar substances but is only moderate for the largest multipolar strengths considered.

New Gibbs ensemble simulation data for a polar fluid modeled by a square-well potential plus dipole-dipole, dipole-quadrupole and quadrupole-quadrupole interactions are presented. This simulation data is used in order to assess the applicability of the multipolar square-well perturbation theory (A. L. Benavides, Y. Guevara, and F. del Río, Physica A 202, 420 (1994) to systems where more than one term in the multipole expansion is relevant. It is found that this theory is able to reproduce qualitatively well the vapor-liquid phase diagram for different multipolar moment strengths, corresponding to typical values of real molecules, except in the critical region. Hence, this theory is used to model the behavior of substances with multiple chemical bonds as carbon monoxide and nitrous oxide and we found that with a suitable choice of the values of the intermolecular parameters, the vapor-liquid equilibrium of these species is adequately estimated.