The Effect of Smoking on Biomarkers of (Anti) oxidant Status

The influence of smoking on the levels of several biomarkers of oxidative stress, antioxidant status and redox status have been investigated in 48 healthy men with a mean age of 25 y. The biomarkers of oxidative stress are the reactive oxygen metabolytes (ROM) and the total oxidant status (TOS). The biomarkers for the antioxidant activity are the biological antioxidant potential (BAP), the ferric reducing ability of plasma (FRAP), the total antioxidant status (TAS), the assay for the defense against the oxidation by hypochlorous acid (OXY) and uric acid (UA). The total thiol levels (TTL) have been measured as a biomarker for the redox status. The average concentration of ROM was 14% higher in smokers compared with non-smokers (p<0.05), whereas TOS was 4.9% higher (not statistically significant).The average concentrations of BAP, FRAP and TAS decreased with smoking with 3.6 (p<0.025), 3.6 (non-significant) and 6.1% (p<0.025), respectively. Alsouric acid, the main antioxidant in serum and a major contributor to the antioxidant status in serum, decreased by 10.6 % (p<0.025) in smokers. The biomarker of the redox status (TTL) was not influenced by smoking. From these results, it is concluded that in epidemiological studies the effect of smoking should be taken in account when using oxidative stress and antioxidant biomarkers

The Effect of Smoking on Biomarkers of (Anti) oxidant Status

The influence of smoking on the levels of several biomarkers of oxidative stress, antioxidant status and redox status have been investigated in 48 healthy men with a mean age of 25 y. The biomarkers of oxidative stress are the reactive oxygen metabolytes (ROM) and the total oxidant status (TOS). The biomarkers for the antioxidant activity are the biological antioxidant potential (BAP), the ferric reducing ability of plasma (FRAP), the total antioxidant status (TAS), the assay for the defense against the oxidation by hypochlorous acid (OXY) and uric acid (UA). The total thiol levels (TTL) have been measured as a biomarker for the redox status. The average concentration of ROM was 14% higher in smokers compared with non-smokers (p<0.05), whereas TOS was 4.9% higher (not statistically significant).The average concentrations of BAP, FRAP and TAS decreased with smoking with 3.6 (p<0.025), 3.6 (non-significant) and 6.1% (p<0.025), respectively. Alsouric acid, the main antioxidant in serum and a major contributor to the antioxidant status in serum, decreased by 10.6 % (p<0.025) in smokers. The biomarker of the redox status (TTL) was not influenced by smoking. From these results, it is concluded that in epidemiological studies the effect of smoking should be taken in account when using oxidative stress and antioxidant biomarkers

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textabstractIntroduction. Surgery-induced oxidative stress increases the risk of perioperative complications and delay in postoperative recovery. In mice, short-term preoperative dietary and protein restriction protect against oxidative stress. We investigated the feasibility of a calorie- and protein-restricted diet in two patient populations. Methods. In this pilot study, 30 live kidney donors and 38 morbidly obese patients awaiting surgery were randomized into three groups: a restricted diet group, who received a synthetic liquid diet with 30% fewer calories and 80% less protein for five consecutive days; a group who received a synthetic diet containing the daily energy requirements (DER); and a control group. Feasibility was assessed using self-reported discomfort, body weight changes, and metabolic parameters in blood samples. Results. Twenty patients (71%) complied with the restricted and 13 (65%) with the DER-diet. In total, 68% of the patients reported minor discomfort that resolved after normal eating resumed. The mean weight loss on the restricted diet was significantly greater (2.4 kg) than in the control group (0 kg, p = 0.002), but not in the DER-diet (1.5 kg). The restricted diet significantly reduced levels of serum urea and plasma prealbumin (PAB) and retinol binding protein (RBP). Conclusions. A short-term preoperative calorie- and protein-restricted diet is feasible in kidney donors and morbidly obese patients. Compliance is high and can be objectively measured via changes in urea, PAB, and RBP levels. These results demonstrate that this diet can be used to study the effects of dietary restriction on surgery-induced oxidative stress in a clinical setting

Quality control data of physiological and immunological biomarkers measured in serum and plasma

In two work packages of the MARK-AGE project, 37 immunological and physiological biomarkers were measured in 3637 serum, plasma or blood samples in five batches during a period of 4 years. The quality of the serum and plasma samples was very good as judged by the low number of biomarker measurements (only 0.2%) that were rejected because of a high hemolysis, icteria or lipemia of the samples. Using quality control samples, day-to-day and batch variations were determined. The mean inter-assay variation of the five batches were all below 8%, with an average inter-assay coefficient of variation of all biomarkers of 4.0%. Also the precision of the measurements was very good, because all measurements were between 90% and 115% of the defined target values. A possible mix-up of samples was determined by comparison of the extreme testosterone levels of men and women. It was concluded that 3% of the sample identification could be mixed-up. Considering the complex procedure from collection to analysis, including preparation, handling, shipment and storage, of the samples in the MARK-AGE project, both the quality of the samples and the quality of the measurements are very good

Validation of biomarkers of oxidative stress in large-scale human studies

Objectives. Oxidative stress has been proposed to be important in age-related processes and chronic diseases. Before biomarkers of oxidative stress are measured in large-scale human studies, they need validation on storage stability and other characteristics. Amongst several candidates (MDA, FRAP, TAS, TOS, GSH, GPX, SOD), three biomarkers were selected which cover different aspects of the oxidative stress process. Methodology. ROM (Reactive Oxygen Metabolites, Diacron) was used as biomarker of oxidative stress, BAP (Biological Antioxidant Potential, Diacron) for anti-oxidant status and TTL (Total Thiol Levels, RelAssay) for the redox status. (DX, Beckman-Coulter). Results. The assays for the biomarkers ROM, BAP and TTL were adapted for an auto-analyzer (DX, Beckman-Coulter) with very good reproducibility. The biomarkers were stable on short- and long-term storage. Also they showed no significant differences in blood samplings at different times of the day, not a post-prandial effect. This set of biomarkers was successfully applied in several large-scale European studies (total 20,000 samples) on aging and nutrition. Conclusion. A set of three biomarkers of oxidative stress was selected for use on an auto-analyzer and applied successfully in large-scale European studies

Biomarkers of (anti)oxidant status in human nutrition, aging and disease

The (anti)oxidant status of individuals is an important factor for the risks of chronic diseases. Biomarker measurements in serum/plasma is a good way to determine the status of the oxidant/antioxidant balance. From our own experience, we come to a proposal of a set of biomarkers for nutritional intake of antioxidants to determine the (anti)oxidant status in serum as a reflection of nutrition. Serum concentrations of biomarkers of fat-soluble vitamins are not suitable to assess transient changes in nutritional intake, because of their strong homeostasis. For long-term epidemiological studies however, they are weil-suited. In addition, a number of oxidation/redox biomarkers can be used in addition to the antioxidant to assess possible relations with health risks. The best biomarkers for this purpose are the reactive oxygen metabolites and total thiols. Examples will be given from large-scale European studies. With the combination of vitamin A, vitamin E, carotenoids (as measured with HPLC), vitamin C, reactive oxygen metabolites, biological antioxidant potency and total thiols (as measured with an auto analyzer), an overall view is obtained concerning the intake and effect of antioxidants in nutrition and aging research. In this paper we describe the methods to measure a selection of these biomarkers in general population. Critical points in biomarker validation with respect to blood sampling, storage conditions and assay stability are discussed

Long term stability of paraoxonase-1 and high-density lipoprotein in human serum

<p>Abstract</p> <p>Background</p> <p>Paraoxonase-1 (PON1) is an enzyme with numerous functions and receives an increasing interest in clinical and epidemiological studies. Sometimes samples are stored for longer periods at a certain temperature. Therefore the stability of PON1 activity must be checked and retained upon storage for longer periods.</p> <p>Results</p> <p>In this study the stability of PON1 activity has been tested in human serum samples during storage up to 12 months at 3 commonly used temperatures, -20°C, -70°C and −196°C. It was found that the stability of the PON1 activity is constant during 12 months of storage at −70°C and −196°C. Storage at −20°C resulted in a small but statistically significant decrease after 6 months to about 94% of its original value. Nonetheless, the rank order between the samples at T = 0 and 12 months remained the same. The same temperature dependence was found for the associated high-density lipoprotein.</p> <p>Conclusions</p> <p>It can be concluded that −70°C is the right temperature for storage to maintain the PON1 activity for at least one year. Storage at a lower temperature in liquid nitrogen (−196°C) is not necessary.</p

Stability of Folate and Vitamin B12 in Human Serum after Long-Term Storage: A Follow-Up after 13 Years

In epidemiological and nutrition research, it is very important to evaluate the stability of biomarkers as function of both storage time and temperature. In this study, the stability of folate and vitamin B12 in human serum samples has been tested after long-term storage at −80°C up to 13 years. Serum samples of 16 individuals were used in this study. The concentration of folate and vitamin B12 has been determined at t=0 and at 1, 8, and 13 years after storage at −80°C. The folate concentrations in serum samples remained stable at −80°C. The concentration of vitamin B12 was decreasing during the time of the study to about 50%. The correlation of the folate and also of the vitamin B12 concentrations in the stored samples compared with the starting values was still good. Therefore, although the concentration of vitamin B12 decreased upon storage, reliable comparative analyses can still be performed

Very long-term stability of lipid biomarkers in human serum.

The assessment of the stability of biomarkers is very important for epidemiological studies. In this study, the stability of five lipid parameters (total cholesterol, triglycerides, HDL- and LDL-cholesterol and free fatty acids) has been tested in 16 human serum samples after storage at -80 degrees C up at time points 0, 1, 8 and 13 y. The majority of the lipid biomarkers were stable during storage conditions, except for cholesterol. The correlations between the samples were very good at time points. Therefore, long-term storage of human serum samples allows lipid biomarker determination, provided that the samples are stored at -80 degrees C.Stanovení stability biomarkerů je velmi důležité zvláště pro epidemiologické studie. Stabilita pěti lipidových parametrů (celkový cholesterol, triacylglyceroly, HDL- a LDL-cholesterol a volné mastné kyseliny) byla testována v 16 vzorcích lidského séra po skladování při -80°C v časových bodech 0, 1, 8 a 13 let. Většina lipidových biomarkerů byla stabilní po dobu skladování kromě cholesterolu. Korelace mezi vzorky v jednotlivých časových bodech byla velmi dobrá. Z toho důvodu, dlouhodobé skladování vzorků lidského séra dovoluje stanovení lipidových biomarkerů za podmínky skladování při -80°C