El ejercicio físico disminuye el estrés laboral y oxidativo en profesionales de Urgencias / Physical exercise reduces occupational and oxidative stress in Emergency Department staff

Fundamento. Situaciones estresantes conducen a la formación de un exceso de radicales libres, que constituyen la mayor amenaza para la homeostasis celular de organismos aerobios. El burnout es un síndrome de estrés crónico laboral. Objetivos. 1. Determinar tanto el estrés oxidativo como el estrés laboral al que se encuentran sometidos profesionales sanitarios de un servicio de urgencias. 2. Analizar la influencia que la práctica de ejercicio físico puede ejercer tanto sobre el estrés oxidativo como sobre el estrés laboral de estos profesionales. Material y métodos. Se han analizado 70 profesionales de un servicio de urgencias hospitalarias y un grupo control de 80 individuos sanos y edades similares. En todos se determinó la actividad de superóxido dismutasa (SOD) y catalasa (CAT), los niveles de malondialdehído (MDA) y del burnout y sus componentes. Resultados. No se han observado diferencias significativas entre varones y mujeres ni en la actividad de SOD y CAT, ni en los niveles de MDA ni en los niveles del burnout. Los niveles de MDA aumentan con la edad en profesionales sanitarios y en el grupo control, con diferencias significativas entre distintos grupos de edad. El estado civil no influye en las variables analizadas. Conclusiones. La peroxidación lipídica y el estrés laboral (niveles de burnout) disminuyen con la práctica de ejercicio físico, siendo los niveles más bajos para los que hacen ejercicio diariamente. Hacer deporte habitualmente, sobre todo cuando no es agotador, resulta una práctica beneficiosa para la prevención tanto del estrés oxidativo como del estrés laboral (AU)

Background. Stressful conditions lead to the formation of excessive free radicals which represents the greatest threat to cellular homeostasis of aerobic organisms. Burnout is a syndrome of chronic occupational stress. Objectives. This work focuses on the determination of both oxidative stress and occupational stress in a medical emergency service staff, and to analyze the effect that performing physical exercise can have on oxidative and occupational stress in these professionals. Material and methods. The study sample consisted of 70 professionals working in a medical emergency service and a control group of 80 age-matched healthy individuals. Superoxide dismutase (SOD) and catalase (CAT) activities, and malondialdehyde (MDA) were determined, as well as burnout with its components. Results. No significant variations were observed in SOD, CAT, MDA, or burnout levels as regards to gender. MDA levels increased with age in both the medical emergency service staff and the control group, with significant differences between the medical emergency service staff and the control group for all age groups. Marital status does not influence the variables analyzed. Conclusions. Lipid peroxidation and occupational stress (burnout levels) decrease with physical exercise, being lower levels for those who practice it daily. Playing sports regularly, especially when it is not exhausting, is a beneficial practice for preventing both oxidative stress and occupational stress (AU)

Biomarkers of age effect on renal function in Down syndrome.

OBJECTIVE: To assess differences in kidney function between Down syndrome (DS) individuals and a control group related to aging. METHODS: Creatinine (Cr) and specific gravity (SG) were assessed by spectrophotometric and refractometric assays in urine samples of 103 individuals with DS and 82 age-matched controls. RESULTS: Significantly lower levels of Cr and SG were found in DS after puberty. Significant correlations were found between SG and age as well as between Cr and SG in DS and controls (p ≤ 0.05). CONCLUSIONS: Premature aging in kidneys of DS patients could lead to an impaired renal function.

Evaluation of urinary biomarkers of oxidative/nitrosative stress in children with Down syndrome.

AIMS: It has been suggested that oxidative stress plays a key role in the pathogenesis of Down syndrome (DS). However, urinary biomarkers of oxidative stress have been little studied in this condition. Thus, we aimed to assess a set of urinary oxidative/nitrosative stress biomarkers in children with DS, with and without hypothyroidism, which comprise: 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs), dityrosine (diTyr), hydrogen peroxide (H(2)O(2)) and nitrite/nitrate (NOx). MAIN METHODS: Fluorimetric and spectrophotometric assays were performed in children with DS (n=26), some of them taking levothyroxine for hypothyroidism (n=7), and their non-Down siblings (n=19). KEY FINDINGS: We found that only levels of diTyr were increased in DS, although no differences were obtained when hypothyroid DS children were excluded. Levels of 8-OHdG, 15-F(2t)-IsoP, TBARS, AGEs, H(2)O(2) and NOx did not differ neither between DS and controls nor between hypothyroid DS children and DS without hypothyroidism diagnosed. However, diTyr is increased in hypothyroid DS children compared with controls. Negative correlations with age were obtained for 8-OHdG, diTyr and NOx in DS and controls and for 8-OHdG, 15-F(2t)-IsoP, TBARS and AGEs in DS. SIGNIFICANCE: Increased oxidative stress in children with DS cannot be explained by the urinary levels of 8-OHdG, 15-F(2t)-IsoP, TBARS, AGEs, diTyr, H(2)O(2) and NOx, at least with the assays used. Nonetheless, urinary diTyr could be used as oxidative/nitrosative stress biomarker in hypothyroid DS children. The present work presents evidence of a probable renal impairment in children with DS receiving levothyroxine for hypothyroidism.

Urinary biomarkers of oxidative/nitrosative stress in healthy smokers.

OBJECTIVE: To evaluate the effect of cigarette smoking on oxidative and nitrosative stress, we assessed urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end-products (AGEs), dityrosine (diTyr), hydrogen peroxide, total nitrite and nitrate and trolox equivalent antioxidant capacity (TEAC) in healthy smokers. METHODS: Fluorimetric and spectrophotometric assays were performed in urine samples of 33 healthy smokers and 58 age-matched controls. RESULTS: Levels of 8-OHdG, 15-F(2t)-IsoP and AGES were found significantly higher in smokers than in controls (10.7 ng/mg Cr vs. 8.3 ng/mg Cr, 1.41 ng/mg Cr vs. 1.01 ng/mg Cr and 189 AFU/mg Cr vs. 143 AFU/mg Cr, respectively; P < 0.05 for all). Positive correlations were found between age and levels of AGEs and diTyr in smokers (r = 0.380, P < 0.035 and r = 0.418, P < 0.019, respectively) and also between age and AGEs, diTyr and TEAC in controls (r = 0.474, P < 0.001, r = 0.463, P < 0.001 and r = 0.576, P < 0.001, respectively), being this correlation negative for 8-OHdG in controls (r = -0.295, P = 0.041). Positive correlation between the number of cigarettes smoked per day and AGEs was also found (r = 0.355, P = 0.044). CONCLUSION: Urinary 8-OHdG, 15-F(2t)-IsoP and AGEs may represent a non-invasive quantitative index of oxidant stress in healthy smokers, being AGEs a possible indicator of tobacco toxin exposure. The increased oxidative stress in healthy smokers observed may be generated because of an excessive production of reactive oxygen species and not by exhaustion of antioxidant defenses.

Evaluation of urinary biomarkers of oxidative/nitrosative stress in adolescents and adults with Down syndrome.

Urinary biomarkers of oxidative stress have been little studied in adults with Down syndrome (DS), usually no more than two biomarkers have been measured in the population studied and controversial results are reported in literature. Thus, we aimed to assess a set of oxidative and nitrosative stress biomarkers in urine samples of adolescents and adults with DS, with and without hypothyroidism, which comprise: 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs), dityrosine (diTyr), hydrogen peroxide (H(2)O(2)) and nitrite/nitrate (NOx). Fluorimetric and spectrophotometric assays were performed in DS (n=78), some of them taking levothyroxine for hypothyroidism (n=24), and in their healthy age-matched controls (n=65). We found that levels of AGEs, diTyr, H(2)O(2) and NOx are increased in DS patients in any or in all age groups, whereas Cr levels were lower in DS than in controls in all age groups. Besides, correlations with age in DS were positive for diTyr and negative for Cr, TBARS, 15-F(2t)-IsoP and NOx. We also found lower levels of Cr from 15 to 19years, higher levels of TBARS and AGEs from 20 to 40years and higher levels of diTyr from 15 to 40years in DS patients receiving levothyroxine than in DS without hypothyroidism diagnosed. We conclude that AGEs, diTyr, H(2)O(2) and NOx could be used as oxidative stress biomarkers in DS in contrast to 8-OHdG, 15-F(2t)-IsoP and TBARS, at least with the methods used. However, renal impairment could occur in DS and Cr adjustment may bias the results, particularly in hypothyroid patients.

Urinary uric acid and antioxidant capacity in children and adults with Down syndrome.

OBJECTIVES: To evaluate the urinary levels of uric acid (UA) and total antioxidant capacity (TAC) with and without UA relative contribution (TAC(-UA)) in children and adults with Down syndrome (DS) and to prove the clinical use of TAC. DESIGN AND METHODS: Urine samples were obtained from 32 individuals with DS and 29 controls. Two age groups were established (children and adults). Spectrophotometric methods were used for biochemical determinations. RESULTS: Children with DS had significantly higher UA/Cr and TAC/Cr levels than controls, whereas levels of TAC(-UA)/Cr were lower in adults with DS than in controls (P<0.05 for all). In DS, levels of UA/Cr, TAC/Cr and TAC(-UA)/Cr were higher in children than in adults (P<0.05 for all). Positive correlations between UA/Cr and TAC/Cr were found for all groups studied. Negative correlations with age were found for UA/Cr and TAC/Cr in children of both groups. CONCLUSIONS: Our results proved that TAC is decreased in adults with DS. Besides, TAC(-UA) seems to provide more reliable information about the antioxidant status, at least in DS.

Evaluation of the copper(II) reduction assay using bathocuproinedisulfonic acid disodium salt for the total antioxidant capacity assessment: the CUPRAC-BCS assay.

There is heightened interest in determining antioxidant status of individuals in experimental and clinical studies investigating progression of diseases or diverse aspects of oxidative stress, among others. The aim of this study was to evaluate the copper(II) reduction assay with bathocuproinedisulfonic acid disodium salt as chelating agent (the CUPRAC-BCS assay) for the total antioxidant capacity (TAC) assessment in human plasma and urine. Samples from 20 individuals were determined with four spectrophotometric assays-CUPRAC-BCS, ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), and 1,1-diphenyl-2-picrylhydrazyl assay (DPPH)-to compare these methods. CUPRAC-BCS was significantly correlated with FRAP and TEAC for plasma and urine samples (r>0.5, P<0.05 for all) and with DPPH for urine samples (r=0.925, P<0.001) but not with DPPH for plasma samples (r=0.366, P=0.112). However, the four methods do not agree given that lines of equality and regression were not matched up. The imprecision of the method is less than 6%, the detection limit is 41.8 micromol trolox equivalents/L, it is linear up to 2 mM trolox, and ethylenediaminetetraacetic acid dihydrate disodium salt (EDTA) binds to Cu(II), avoiding the formation of Cu(I)-BCS complex. This study shows that CUPRAC-BCS is a simple, fast, inexpensive, and suitable method for TAC assessment in human urine and heparinized plasma samples.

Lipid peroxidation, occupational stress and aging in workers of a prehospital emergency service.

BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.

Malondialdehyde: a possible marker of ageing.

BACKGROUND: Numerous recent studies have suggested that oxidative damage may be important in the ageing process, and lipid peroxidation is an important biological consequence of oxidative cellular damage. OBJECTIVE: The aim of this work was to analyze the activities of the two protective enzymes, superoxide dismutase (SOD) and catalase (CAT), and the levels of malondialdehyde (MDA) to examine the relationship between the ageing process and defence antioxidant and lipid peroxidation. METHOD: SOD activity was measured in red blood cells using the Minami and Yoshikawa method; CAT activity was measured in hemolysates by the Aebi method, and MDA levels were measured in erythrocytes by high-performance liquid chromatography. RESULTS: SOD activity shows statistically significant differences between newborns and the rest of the sample (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.001). CAT activity did not show significant differences between the age groups. We observed statistically significant differences in MDA levels between the different groups (ANOVA p < 0.001; Student-Newman-Keuls test p < 0.05). In the regression analysis and rectilinear/curvilinear adjustment compared to age, SOD and CAT showed coefficients close to zero (SOD linear = 0.16; SOD exponential = 0.15; CAT linear = 0.056; CAT exponential = 0.068), indicating in that way their independence from age. Only MDA obtained a regression coefficient superior to 0.75 (p < 0.05). The best adjustment was reached through an exponential expression, giving the following parametric relation: MDA = 103.117e(0.0021.AGE). No statistically significant variation in SOD and CAT activity and MDA levels, related to sex could be demonstrated. CONCLUSIONS: Our data show that old age is associated with an increase in systemic oxidative stress.

Niveles de superóxido dismutasa y catalasa en enfermedades del anciano / Dismutase and catalase superoxide levels in pathologies of the elderly

Se han determinado los niveles de superóxido dismutasa (SOD) y catalasa (CAT) en 420 individuos de uno y otro sexo y edades comprendidas entre 50 y 93 años. De ellos, 126 que no mostraban ninguna enfermedad relevante se utilizaron como grupo control. Los 294 restantes mostraban diferentes trastornos: alteraciones del sistema vascular (insuficiencias coronarias, hipertensión, infarto, etc.), alteraciones del sistema osteoarticular (artritis, polialtralgias, osteoporosis, etc.), miomas, afecciones, prostáticas, enfermedad pulmonar obstructiva crónica (EPOC) y accidente cerebral vascular agudo (ACVA). Para valorar SOD se utilizó el método de minami y Yoshikawa y el método de Aebi para valorar CAT. Métodos estadísticos: ANOVA y "t" de Student. En la población control se han obtenido: 1) niveles de SOD y CAT más elevados en mujeres que en varones. 2) la actividad de CAT disminuye con la edad. En la población con patologías: 3) la actividad de SOD está elevada en cardiovascular, miomas, EPOC y ACVA. 4) la actividad de CAT desciende en cardiovascular, próstata, EPOC y ACVA. 5) en osteoarticular actividad normal de SOD y CAT, aunque SOD desciende con la edad, CAT desciende con la edad en cardiovascular y EPOC. En general el comportamiento de ambos enzimas tiende a conseguir un equilibrio en el sistema antioxidante