Using Redox Proteomics to Gain New Insights into Neurodegenerative Disease and Protein Modification.

Antioxidant defenses in biological systems ensure redox homeostasis, regulating baseline levels of reactive oxygen and nitrogen species (ROS and RNS). Oxidative stress (OS), characterized by a lack of antioxidant defenses or an elevation in ROS and RNS, may cause a modification of biomolecules, ROS being primarily absorbed by proteins. As a result of both genome and environment interactions, proteomics provides complete information about a cell's proteome, which changes continuously. Besides measuring protein expression levels, proteomics can also be used to identify protein modifications, localizations, the effects of added agents, and the interactions between proteins. Several oxidative processes are frequently used to modify proteins post-translationally, including carbonylation, oxidation of amino acid side chains, glycation, or lipid peroxidation, which produces highly reactive alkenals. Reactive alkenals, such as 4-hydroxy-2-nonenal, are added to cysteine (Cys), lysine (Lys), or histidine (His) residues by a Michael addition, and tyrosine (Tyr) residues are nitrated and Cys residues are nitrosylated by a Michael addition. Oxidative and nitrosative stress have been implicated in many neurodegenerative diseases as a result of oxidative damage to the brain, which may be especially vulnerable due to the large consumption of dioxygen. Therefore, the current methods applied for the detection, identification, and quantification in redox proteomics are of great interest. This review describes the main protein modifications classified as chemical reactions. Finally, we discuss the importance of redox proteomics to health and describe the analytical methods used in redox proteomics.

Evolution of Vitamin D Status and Vitamin D Receptor Gene Expression Among Professional Handball Athletes During a Competitive Period. Relationship with Body Composition, Calcium, Magnesium and Phosphorous.

INTRODUCTION: A generalized risk of vitamin D deficiency exists worldwide affecting also professional and elite athletes. This study assesses the evolution of vitamin D status and vitamin D receptor (VDR) gene expression and their relationship with body composition, calcium (Ca), magnesium (Mg) and phosphorous (P) among professional handball athletes during a competitive period. METHODS: A total of 26 male subjects were recruited: 13 professional handball athletes and 13 non-athlete controls. An observational follow-up study was conducted in 2 time points over a 16-week period. Nutritional intake, body composition, and routinary biochemical parameters were measured via 24-hours recall, bioimpedance and enzyme immunoassay, respectively. Ca and Mg were measured by flame atomic absorption spectrophotometry and P was determined with the colorimetric method of Fiske-Subbarow. 25-hydroxyvitamin-D (25(OH)D) levels and its forms (i.e., 25(OH)D3 and 25(OH)D2) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), whereas VDR gene expression was measured by quantitative real time-polymerase chain reaction (qRT-PCR). RESULTS: A total of 54% of the athletes showed deficient vitamin D status. Moreover, a prevalence of insufficient vitamin D status in handball players affected 46% at baseline, reaching 61% after 16 weeks. Vitamin D showed no evolution during the competitive period and no differences between groups were observed (all p ≥ 0.05). Handball players increased the VDR expression, enhanced body composition, Ca and Mg levels at 16-weeks follow-up (all p < 0.05). VDR gene expression was positively related with body mass and body mass index at follow-up in athletes (all p ≤ 0.038; r ≥ 0.579) and with Ca at baseline in controls (p = 0.026; r = 0.648). Finally, 25(OH)D2 form was directly associated with P in athletes at 16 weeks of study (p = 0.034; r = 0.588). CONCLUSION: Players of indoor team sports such as handball would be a population at risk of vitamin D deficiency. The 16-weeks competition improved VDR gene expression, body composition, Ca and Mg levels. The associations observed between VDR gene expression and the variables of the study evidenced the importance of this receptor as a marker involved in health status in handball athletes despite vitamin D - although in a deficient status -, Ca, Mg and P showed no remarkable changes during the competition period.

Prevalence of sports supplements consumption and its association with food choices among female elite football players.

OBJECTIVES: The present study aimed to 1) investigate the consumption of Sports Supplements (SSs) among female elite football players, 2) evaluate the influence of age on SS consumption, and 3) determine the relationship between the consumption of SSs and dietary choices among elite football players. METHODS: A total of 126 female football players of Primera Iberdrola and Reto Iberdrola who participated in this descriptive, observational, and cross-sectional study completed a self-administered questionnaire on SSs and the Athletes' Food Choices Questionnaire. RESULTS: Overall, 84.1% of participants consumed supplements, mainly for improved sports performance (68.3%) and health (34.1%). The main sources of purchase were the Internet (34.9%) and specialized shops (23.8%), and players were commonly advised by a dietitian-nutritionist to use SSs (56.3%). The SSs most often consumed included whey protein (30.2%), sports drinks (28.6%), creatine monohydrate (28.6%), sports bars (27.8%), and caffeine (27.8%). Older players consumed more supplements at the time of data compilation. Players predominantly acquired these supplements by using the Internet and reported benefits from their use (all P ≤ 0.036). Additionally, players who consumed SSs conveyed more concern about their food choices. CONCLUSIONS: A high prevalence of female football players consumed SSs, particularly SSs supported by robust scientific evidence. Older players had higher supplement consumption rates. The use of SSs was related to food choices through nutritional characteristics of foods, knowledge about health and nutrition, weight control with the help of food, and the performance benefits players could acquire.

Evolution of Status of Trace Elements and Metallothioneins in Patients with COVID-19: Relationship with Clinical, Biochemical, and Inflammatory Parameters.

The inflammatory reaction and pathogenesis of COVID-19 may be modulated by circulating trace elements (Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn)) and Metallothioneins (MTs). Thus, the present study aimed to investigate their relationship with clinical, biochemical, and inflammatory parameters in patients with COVID-19 at the early Intensive Care Unit (ICU) phase. Critically ill patients (n = 86) were monitored from the first day of ICU admission until the third day of stay. Serum samples were used to assess mineral levels via Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and MT levels via differential pulse voltammetry. Levels of Cu and MTs were significantly decreased after 3 days (p < 0.05), increasing the prevalence of Cu-deficient values from 50% to 65.3% (p = 0.015). Fe and Zn were shown to have a predictive value for mortality and severity. The present study suggests trace element deficiency may be a risk factor during early ICU treatment of COVID-19, as it is related to different biochemical and clinical parameters, indicating a possible beneficial effect of restoring proper levels of these micronutrients.

Response to Intravenous N-Acetylcysteine Supplementation in Critically Ill Patients with COVID-19.

Administering N-acetylcysteine (NAC) could counteract the effect of free radicals, improving the clinical evolution of patients admitted to the Intensive Care Unit (ICU). This study aimed to investigate the clinical and biochemical effects of administering NAC to critically ill patients with COVID-19. A randomized controlled clinical trial was conducted on ICU patients (n = 140) with COVID-19 and divided into two groups: patients treated with NAC (NAC-treated group) and patients without NAC treatment (control group). NAC was administered as a continuous infusion with a loading dose and a maintenance dose during the study period (from admission until the third day of ICU stay). NAC-treated patients showed higher PaO2/FiO2 (p ≤ 0.014) after 3 days in ICU than their control group counterparts. Moreover, C-reactive protein (p ≤ 0.001), D-dimer (p ≤ 0.042), and lactate dehydrogenase (p ≤ 0.001) levels decreased on the third day in NAC-treated patients. Glutathione concentrations decreased in both NAC-treated (p ≤ 0.004) and control (p ≤ 0.047) groups after 3 days in ICU; whereas glutathione peroxidase did not change during the ICU stay. The administration of NAC manages to improve the clinical and analytical response of seriously ill patients with COVID-19 compared to the control group. NAC is able to stop the decrease in glutathione concentrations.

Sociodemographic, Anthropometric, Body Composition, Nutritional, and Biochemical Factors Influenced by Age in a Postmenopausal Population: A Cross-Sectional Study.

Postmenopausal aging has become relevant for understanding health during the transition life stages-the aging process being involved in several disturbances of the human condition. The present study aimed to investigate the relationship between postmenopausal aging and sociodemographic, anthropometric, body composition, nutritional, and biochemical (i.e., protein and lipid profiles, phosphorous-calcium metabolism, and antioxidant status) factors in postmenopausal women. This cross-sectional study enrolled 78 healthy postmenopausal women (44-76 years). The anthropometrical data showed no differences by age. Biochemical parameters, especially those involved in the protein and phosphorous-calcium metabolism, were influenced by age in our cohort of postmenopausal women. In contrast, no associations were found when considering lipid and antioxidant parameters. Height, fiber intake, blood glucose, protein profile and phosphorous-calcium metabolism markers seem to be the most affected nutritional-related factors by age in our cohort of healthy postmenopausal women. Primary prevention strategies focused on parameters at risk of disruption with postmenopausal aging are necessary to ensure the quality of life in older ages.

Influence of Nutritional Parameters on the Evolution, Severity and Prognosis of Critically Ill Patients with COVID-19.

This study evaluated the clinical and nutritional status, the evolution over three days, and the relationship between nutritional, inflammatory, and clinical parameters of critically ill patients with COVID-19. A longitudinal study was conducted in the Intensive Care Unit of the Virgen de las Nieves University Hospital in Granada (Spain). The study population comprised patients with a positive polymerase chain reaction test for COVID-19 presenting critical clinical involvement. Clinical outcomes were collected, and inflammatory and nutritional parameters (albumin, prealbumin, transferrin, transferrin saturation index, cholesterol, triglycerides and Controlling Nutritional Status (CONUT) score) were determined. A total of 202 critical patients with COVID-19 were selected, presenting highly altered clinical-nutritional parameters. The evolution experienced by the patients on the third day of admission was a decrease in albumin (p < 0.001) and an increase in prealbumin (p < 0.001), transferrin (p < 0.002), transferrin saturation index (p < 0.018), and cholesterol (p < 0.001). Low levels of albumin, prealbumin (on the third day) and high CONUT score (on the third day) showed an association with higher mortality. Nutritional variables were inversely correlated with clinical and inflammatory parameters. Critically ill patients with COVID-19 have poor nutritional status related to a poor prognosis of disease severity and mortality.

Vitamin D Status in Critically Ill Patients with SIRS and Its Relationship with Circulating Zn and Related Parameters during ICU Stay.

Critically ill patients are exposed to different stressors which may generate Systemic Inflammatory Response Syndrome (SIRS). This situation hinders the assessment of micronutrients status, such as vitamin D or Zinc (Zn), potentially affecting patients' treatment and recovery. The aim of the present study was to assess the evolution of circulating 25-Hydroxyvitamin D (25-OH-D) levels after seven days of Intensive Care Unit (ICU) stay and the influence on changes in plasma and erythrocyte Zn levels, as well as other parameters related to phosphorus-calcium metabolism. A prospective analytical study was conducted on 65 critically ill patients (42% women) aged 31-77 years with SIRS. Total 25-OH-D levels were measured in plasma samples by liquid chromatography-tandem mass spectrometry, and Zn content was analyzed by flame atomic absorption spectrometry. Both 25-OH-D and 25-OH-D3 levels were directly associated with erythrocyte Zn concentration at follow-up (p = 0.046 and p = 0.011, respectively). A relationship between erythrocyte and plasma Zn was also found at this follow-up point. No such clear associations were found when considering 25-OH-D2. Different disturbances in levels of phosphorus-calcium metabolism parameters were found, suggesting a relationship between the changes of 25-OH-D3 levels and parathormone (p = 0.019) and phosphorus (p = 0.005). The findings of the present study suggest an interaction between vitamin D and Zn, in which the correct status of these micronutrients could be a potentially modifiable factor and a beneficial approach in the recovery of critically ill patients.

Relationship between Body Composition and Biochemical Parameters with Antioxidant Status in a Healthy Cohort of Postmenopausal Women.

An adequate prooxidant-antioxidant balance-which may be influenced by body composition and biochemical status-is essential to maintain human health, especially in circumstances under which the antioxidant defense decreases, such as menopause. The present study aimed to examine the relationship between body composition and biochemical parameters with antioxidant status in a healthy cohort of postmenopausal women. This cross-sectional study was carried out in a cohort of 78 postmenopausal women aged 44-76 years. The body composition profile was assessed through bioelectrical impedance. The determination of the total antioxidant capacity and superoxide dismutase activity was conducted by the colorimetric method, and glutathione peroxidase activity was determined by the enzymatic immunological method. The vitamin D levels were measured by ultra-performance liquid chromatography-tandem mass spectrometry. The mineral status was assessed through flame atomic absorption spectrophotometry. The rest of the biochemical parameters were assessed through an immunoassay. The total antioxidant capacity and antioxidant gap were negatively influenced by body composition (all p ≤ 0.049) and positively related to protein metabolism parameters (all p ≤ 0.048), whereas circulating levels of different micronutrients (all p ≤ 0.048) and enzymes (all p ≤ 0.047) appeared to play an important role in the glutathione peroxidase and superoxide dismutase activities. In conclusion, the menopause-related antioxidant status changes may be influenced by key body composition and biochemical profiles. To confirm this statement, further trials aiming to evaluate the body composition and biochemical intervention-induced changes upon antioxidant defense are needed.

Selenium Levels and Antioxidant Activity in Critically Ill Patients with Systemic Inflammatory Response Syndrome.

The Selenium (Se) status could be an important modifiable factor in critically ill patient outcomes due to the important role of this mineral in several functions. Although there are many clinical trials with Se interventions in the literature, the evidence is not sufficient to establish a common criterion regarding the Se status. Background and aims: An analysis was made of the evolution of selenium (Se) and antioxidant status in critically ill patients with Systemic Inflammatory Response Syndrome (SIRS) over 7 days of staying in the Intensive Care Unit (ICU). Methods: A prospective analytical study was carried out on 65 critically ill patients aged 31−77 years. A healthy control group of 56 volunteers from the same region was recruited to allow comparisons with reference normal values. The selenium levels in both the plasma and erythrocytes were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Glutathione Peroxidase (GPx) and Superoxide Dismutase (SOD) activity and the Total Antioxidant Capacity (TAC) were measured using kinetic colorimetric methods. Results: Low erythrocyte and plasma Se levels were found at ICU admission in comparison with the healthy reference group (p < 0.001), and the levels further decreased after one week (p < 0.001). Smaller changes in the plasma Se levels were associated with greater changes in the Sequential Organ Failure Assessment (SOFA) score (p < 0.05). The GPx activity in the critically ill was lower than in the control group (p < 0.05), with an inverse correlation to the severity scores at the baseline (p < 0.05) and reaching normal values after one week (p < 0.05). SOD activity was directly correlated to TAC (p = 0.03), with both parameters exhibiting a direct correlation to albumin (p < 0.05) after 7 days of ICU stay. Conclusions: A deficient Se status was observed at ICU admission and worsened further over follow-up regardless of the evolution of the patient severity and the antioxidant parameters. Adequate Se support from the start of admission could preserve and contribute to improve the Se-related outcomes and critical patient recovery during longer periods in the ICU.

Erythrocyte Zn concentration and antioxidant response after supplementation with Zn in a postmenopausal population. A double-blind randomized trial.

BACKGROUND & AIMS: Menopausal hormonal changes increase the risk of deficiencies of minerals such as zinc (Zn), which could further worsen the decreased antioxidant defense of postmenopausal women. This study assesses the effect of 8 weeks of Zn supplementation upon the antioxidant status and clinical nutritional parameters of a postmenopausal population. METHODS: Fifty-one postmenopausal women were divided into two groups: placebo (PbG) and zinc supplementation (ZnG). Mineral status was determined by Flame Atomic Absorption Spectrophotometry (FAAS). Total Antioxidant Capacity (TAC) and Superoxide Dismutase (SOD) were analyzed by kinetic colorimetric methods. Glutathione Peroxidase (GPx) was assessed by an enzymatic immunological method. RESULTS: Poor Zn status was initially observed in erythrocyte samples. Total antioxidant capacity showed a significant correlation (r = 0.730; p < 0.05) to erythrocyte Zn after the intervention (ZnG: r = 0.96; p < 0.001). Moreover, erythrocyte Zn concentration in ZnG was positively correlated to GPx activity after the intervention (r = 0.61; p < 0.01). CONCLUSIONS: The postmenopausal women initially presented Zn deficiency, and the status of this mineral improved after the intervention. Zinc supplementation may be an effective approach for correcting the observed deficiencies, enhancing antioxidant defense in this risk population. CLINICAL TRIAL REGISTRATION: The present study is registered at the US National Institutes of Health (ClinicalTrials.gov), NCT03672513.

Effect of zinc supplementation on circulating concentrations of homocysteine, vitamin B12, and folate in a postmenopausal population.

INTRODUCTION: The decrease in estrogen levels associated with menopause increases the risk of deficiencies of key micronutrients such as zinc and of disturbances in methylation cycle-related markers. The present study assesses the effect of 8-week Zn supplementation upon circulating concentrations of Hcy, B12, and Fol levels in a population of postmenopausal women. METHODS: Fifty-one postmenopausal women aged between 44 and 76 years took part in the study. Two randomized groups (placebo and zinc [50 mg/day]) were treated during 8 weeks. Nutrient intake was assessed based on the 72-hour recall method. Zinc was analyzed by flame atomic absorption spectrophotometry. Clinical-nutritional parameters were determined by enzyme immunoassay techniques. RESULTS: Folate levels increased significantly (p < 0.05) in the zinc group on comparing the baseline versus follow-up values. Homocysteine decreased in the inter-group analysis (p < 0.05) after the intervention. Furthermore, higher folate (r = -0.632; p = 0.005) and vitamin B12 (r = -0.512; p = 0.030) levels were correlated to low homocysteine levels in the zinc group after the intervention, although the zinc intervention had the same effect on B12 levels in both groups. CONCLUSION: Zinc supplementation enhanced circulating folate and homocysteine by improving the folate values in the zinc-supplemented group and decreasing homocysteine levels inter-groups. Further studies involving larger samples and optimizing the doses and intervention period are needed to reinforce our main findings.

Folic acid and vitamin B12 as biomarkers of morbidity and mortality in patients with septic shock.

Introduction: Introduction and objective: a study was made of the folic acid (Fol) and vitamin B12 (B12) serum concentrations in critical patients with septic shock upon admission and after three days of stay in the Intensive Care Unit (ICU), with an analysis of their association to inflammatory parameters and patient morbidity-mortality. Methods: a prospective analytical study was made of 30 critically ill patients with septic shock. Demographic data, comorbidities, clinical information and severity scores were recorded. Data collected included serum Fol and B12 levels using the DxI® Autoanalyzer (Beckman Coulter) based on a competitive electrochemoluminescence immunoassay. Results: mean serum Fol was within the reference range stipulated by the laboratory on the first day. Nevertheless, a total of 21.4 % of the patients had high Fol levels, with 14.2 % being Fol deficient. An association was observed between Fol (p ˂ 0.012) status and 28-day mortality, and the number of days of mechanical ventilation, fraction of inspired oxygen (FiO2) and fibrinogen increased in patients with higher Fol levels (p ˂ 0.05). In addition, 85.7 % of cases had B12 levels above the reference values, with a correlation being observed between B12 and Fol. Conclusions: this study proposes Fol as a novel morbidity-mortality biomarker in critical septic patients, and reinforces the usefulness of B12 as a morbidity biomarker. It is thus suggested that the measurement of Fol upon admission and over the first 72 hours of hospital stay could provide prognostic information about the clinical course and outcome of septic shock patients.

Introducción: Introducción y objetivo: se realizó un estudio de las concentraciones séricas de ácido fólico (Fol) y vitamina B12 (B12) en pacientes críticos con shock séptico al ingreso y después de tres días de estancia en la Unidad de Cuidados Intensivos (UCI), con un análisis de su asociación con los parámetros inflamatorios y la morbimortalidad de los pacientes. Método: se realizó un estudio analítico prospectivo de 30 pacientes críticos con shock séptico. Se registraron datos demográficos, comorbilidades, información clínica y puntuaciones de gravedad. Los datos recopilados incluyeron los niveles séricos de Fol y B12 utilizando el autoanalizador DxI® (Beckman Coulter) basado en un inmunoensayo de electroquimioluminiscencia competitivo. Resultados: la media de Fol sérico estuvo dentro del rango de referencia estipulado por el laboratorio el primer día. Sin embargo, el 21,4 % de los pacientes presentaban niveles altos de Fol y el 14,2 % presentaban deficiencia de Fol. Se observó una asociación entre el estado de Fol (p ˂ 0,012) con la mortalidad a los 28 días, con el número de días de ventilación mecánica, con la fracción de oxígeno inspirado (FiO2) y con el fibrinógeno, que aumentaron en los pacientes con niveles de Fol más altos (p ˂ 0,05). Además, el 85,7 % de los casos tenían niveles de B12 por encima de los valores de referencia, observándose una correlación entre B12 y Fol. Conclusiones: este estudio propone al Fol como nuevo biomarcador de morbimortalidad en los pacientes críticos con sepsis y refuerza la utilidad de la B12 como biomarcador de morbilidad. Por tanto, se sugiere que la medición de Fol al ingreso y durante las primeras 72 horas de estancia hospitalaria podría proporcionar información pronóstica sobre el curso clínico y el resultado de los pacientes con shock séptico.

Bad Prognosis in Critical Ill Patients with COVID-19 during Short-Term ICU Stay regarding Vitamin D Levels.

BACKGROUND AND AIMS: Vitamin D inadequacy may be involved in the mechanisms of SARS-CoV-2 infection and in potential risk factors for disease propagation or control of coronavirus disease 2019 (COVID-19). This study assessed a short-term evolution of vitamin D status and its influence upon different clinical parameters in critically ill patients with COVID-19. METHODS: A prospective analytical study in which 37 critically ill volunteers between 41 and 71 years of age with COVID-19 were evaluated at baseline and three days of intensive care unit (ICU) stay. 25-OH-D3 and 25-OH-D2 were analyzed by liquid chromatography-tandem mass spectrometry and total 25-OH-D levels were calculated as the sum of both. RESULTS: All patients presented low 25-OH-D levels at baseline, decreasing total 25-OH-D (p = 0.011) mainly through 25-OH-D2 (p = 0.006) levels during ICU stay. 25-OH-D2 levels decreased a mean of 41.6% ± 89.6% versus 7.0% ± 23.4% for the 25-OH-D3 form during the ICU stay. Patients who did not need invasive mechanical ventilation presented higher levels of 25-OH-D2 at baseline and follow-up. Lower 25-OH-D and 25-OH-D3 levels were associated with higher D-dimer at baseline (p = 0.003; p = 0.001) and at follow up (p = 0.029), higher procalcitonin levels (p = 0.002; p = 0.018) at follow up, and lower percentage lymphocyte counts (p = 0.044; p = 0.040) during ICU stay. CONCLUSIONS: Deficient vitamin D status in critical patients was established at the admission and further worsened after three days of stay. Lower vitamin D levels were related to key altered clinical and biochemical parameters on patients with SARS-CoV-2 infection. Given the different response of the 25-OH-D3 and 25-OH-D2 forms, it would be useful to monitor them on the evolution of the critically ill patient.

Effectiveness of eight-week zinc supplementation on vitamin D3 status and leptin levels in a population of postmenopausal women: a double-blind randomized trial.

BACKGROUND: The menopausal period is characterized by hormonal imbalance related to the alteration of parameters involved in lipid metabolism. In addition, menopause increases the risk of deficiencies of key vitamins and minerals such as vitamin D and zinc in such women. The present study investigates the influence of zinc supplementation on the status of vitamin D3 and other lipid parameters in postmenopausal women. METHODS: Fifty-one healthy postmenopausal women aged 44-76 years from the province of Granada (Spain) were divided into two groups (placebo and zinc) of 25 and 26 women, respectively. The zinc group was supplemented with 50 mg/day of zinc for 8 weeks. Nutrient intake assessment was performed by means of a 24 -h reminder. Zinc was determined by flame atomic absorption spectrophotometry. Vitamin D was analyzed by liquid chromatography - tandem mass spectrometry. Leptin was determined by enzyme immunoassay. RESULTS: Zinc supplementation improved the initial vitamin D3 status of the postmenopausal population (p = 0.049). Plasma levels of 25-OH-D3 increased significantly after Zn supplementation in women with lower age at menopause (p = 0.045). Both intake and plasma zinc levels were inversely correlated to serum leptin levels (p = 0.044 and p = 0.033, respectively), being significantly lower in lower age at menopause (p < 0.001). CONCLUSION: Zinc supplementation improved vitamin D3 status and was associated to low leptin levels in the postmenopausal women of the study.

Response of Vitamin D after Magnesium Intervention in a Postmenopausal Population from the Province of Granada, Spain.

Menopause is a stage of hormonal imbalance in women which, in addition to other physiopathological consequences, poses a risk of deficiency of key micronutrients such as magnesium and vitamin D. A study was made of the influence of a magnesium intervention upon vitamin D status in a postmenopausal population from the province of Granada (Spain). Fifty-two healthy postmenopausal women between 44-76 years of age were included. Two randomized groups-placebo and magnesium (500 mg/day)-were treated during eight weeks. Nutrient intake was assessed using questionnaires based on 72-h recall. Vitamin D was analyzed by liquid chromatography-tandem mass spectrometry. Baseline vitamin D proved deficient in over 80% of the subjects. The administration of magnesium resulted in significantly increased vitamin D levels in the intervention group versus the controls (p < 0.05). Magnesium supplementation improved vitamin D status in the studied postmenopausal women.

Association between Body Fatness and Vitamin D3 Status in a Postmenopausal Population.

Vitamin D is a micronutrient that plays a key role in phosphocalcic metabolism. The postmenopausal population presents a risk of deficiency in this vitamin due to hormonal alterations which, in the case of obesity, would be exacerbated. The objective was to assess the status of vitamin D in a postmenopausal population and determine the relationship of 25-hydroxivitamin D [25(OH)D] and its metabolites with anthropometric parameters. The study included 78 healthy postmenopausal women aged from 44 to 76. The nutrient intake assessment was carried out using the 24 h reminder (R24h). 25(OH)D was analyzed using ultra-high-performance liquid chromatography (UHPLC). A total of 80% and 68% of the women studied did not reach sufficient values of 25(OH)D and 25-hydroxivitamin D3 [25(OH)D3], respectively, which was inversely correlated with Body Mass Index (BMI) (r = -0.25, p = 0.04), hip perimeter (r = -0.26 and r = -0.24, all p < 0.05), arm circumference (r = -0.29, p = 0.01) and fat mass (r = -0.28 and r = -0.26, all p < 0.05). 25(OH)D3 is the metabolite that contributed most to this association. In conclusion, 25(OH)D3 levels are related to anthropometric parameters in the postmenopausal women in this study, confirming insufficient status in the majority of the population. Approach strategies are necessary to correct and avoid this risk in order to ensure future quality of life.

Current trends in the analytical determination of vitamin D / Tendencias actuales en la determinación analítica de vitamina D

Vitamin D is a micronutrient that plays a large role in bone disease, and researchers are now discovering that it also does so in non-skeletal disease, thus making high-quality analytical determination necessary. To make this determination, a series of immunochemical and physical methods are used. These methods present a series of different ways of handling samples as well as different methodologies that bring a series of advantages and limitations based on the scope of work in which the vitamin D analysis methodology is applied. Although the Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) is the gold standard method of analytical vitamin D determination, and is the only one to offer a more complete and accurate view of all metabolites of this vitamin, it is necessary to standardize all the analysis methodologies that allow accurate, reliable and quality analytical determination, since it is essential to obtain results that can reliably be extrapolated to the population, and that can be decisive in assessing a large number of pathologies

La vitamina D es un micronutriente que ejerce un gran papel en enfermedades óseas y actualmente se está descubriendo que también lo hace en enfermedades no óseas, por lo que una determinación analítica de calidad es necesaria. Para realizar esta determinación se emplean una serie de métodos inmunoquímicos y físicos, los cuales van a presentar una serie de tratamientos diferentes de las muestras, así como diferentes metodologías que van a traer una serie de ventajas y limitaciones conforme al ámbito de trabajo en que se aplique la metodología de análisis de la vitamina D. A pesar de que la cromatografía líquida-espectrometría de masas en tándem (LC-MS/MS) es el método gold standard de determinación analítica de la vitamina D, y de que es el que ofrece una visión más completa y precisa de todos los metabolitos de esta vitamina, es necesaria una estandarización de todas las metodologías de análisis que permitan una determinación analítica precisa, fiable y de calidad, ya que es imprescindible obtener unos resultados que sean extrapolables con fiabilidad a la población y que puedan ser determinantes para valorar un gran número de patologías

Current trends in the analytical determination of vitamin D.

INTRODUCTION: Vitamin D is a micronutrient that plays a large role in bone disease, and researchers are now discovering that it also does so in non-skeletal disease, thus making high-quality analytical determination necessary. To make this determination, a series of immunochemical and physical methods are used. These methods present a series of different ways of handling samples as well as different methodologies that bring a series of advantages and limitations based on the scope of work in which the vitamin D analysis methodology is applied. Although the Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) is the gold standard method of analytical vitamin D determination, and is the only one to offer a more complete and accurate view of all metabolites of this vitamin, it is necessary to standardize all the analysis methodologies that allow accurate, reliable and quality analytical determination, since it is essential to obtain results that can reliably be extrapolated to the population, and that can be decisive in assessing a large number of pathologies.

INTRODUCCIÓN: La vitamina D es un micronutriente que ejerce un gran papel en enfermedades óseas y actualmente se está descubriendo que también lo hace en enfermedades no óseas, por lo que una determinación analítica de calidad es necesaria. Para realizar esta determinación se emplean una serie de métodos inmunoquímicos y físicos, los cuales van a presentar una serie de tratamientos diferentes de las muestras, así como diferentes metodologías que van a traer una serie de ventajas y limitaciones conforme al ámbito de trabajo en que se aplique la metodología de análisis de la vitamina D. A pesar de que la cromatografía líquida-espectrometría de masas en tándem (LC-MS/MS) es el método gold standard de determinación analítica de la vitamina D, y de que es el que ofrece una visión más completa y precisa de todos los metabolitos de esta vitamina, es necesaria una estandarización de todas las metodologías de análisis que permitan una determinación analítica precisa, fiable y de calidad, ya que es imprescindible obtener unos resultados que sean extrapolables con fiabilidad a la población y que puedan ser determinantes para valorar un gran número de patologías.

Pyroglutamic acidosis by glutathione regeneration blockage in critical patients with septic shock.

AIM: The aim of this study was to evaluate oxidative stress from glutathione depletion in critically ill patients with a septic shock through the abnormal presence of pyroglutamic acid (PyroGlu) in the urine (indirectly) and through its serum level (directly). METHODS: This was a prospective analytical study of 28 critically ill patients with a septic shock who were monitored from admission (initial) to 3 days of stay (final) in the intensive care unit (ICU). Data collected included PyroGlu and glutamic acid (Glu) using liquid chromatography/mass spectrometry, and glutathione peroxidase (GPX) activity with a colorimetric assay. The differences in Glu, PyroGlu, and GPX activity between the septic shock group and healthy control group serving as reference values were evaluated using the Mann-Whitney test. The correlations between Glu, PyroGlu, and GPX activity and clinical outcomes were determined using Spearman's correlation coefficient. RESULTS: In patients with septic shock, serum and urine PyroGlu levels were higher, erythrocyte GPX activity/gr Hb was lower, and urine Glu levels were lower compared to healthy control reference values, for both initial and final values. Initial serum Glu levels were also lower. Serum PyroGlu levels had a correlation with both initial and final serum Glu levels; levels also correlated in the urine. Initial serum Glu correlated with the days of mechanical ventilation (P = 0.016) and the days of ICU stay (P = 0.05). Urine Glu/mg creatinine correlated with APACHE II (P = 0.030). This positive correlation observed for serum Glu was not observed for PyroGlu. CONCLUSIONS: The current study found that septic patients have higher levels of PyroGlu, lower levels of Glu, and lower erythrocyte GPX activity, suggesting that these biomarkers could be used as an indicator of glutathione depletion. In addition, Glu is related to severity parameters. This study can guide future studies on the importance of monitoring the levels of pyroglutamic acidosis in critical patients with septic shock in order to preserve the oxidative status and its evolution during the stay in the ICU.