[Reference ranges of antioxidant parameters in whole blood (erythrocytes) in a Thüringen region]

The importance of intraoperative selenium blood levels on organ dysfunction in patients undergoing off-pump cardiac surgery: a randomised controlled trial

INTRODUCTION

Cardiac surgery is accompanied by an increase of oxidative stress, a significantly reduced antioxidant (AOX) capacity, postoperative inflammation, all of which may promote the development of organ dysfunction and an increase in mortality. Selenium is an essential co-factor of various antioxidant enzymes. We hypothesized a less pronounced decrease of circulating selenium levels in patients undergoing off-pump coronary artery bypass (OPCAB) surgery due to less intraoperative oxidative stress.

METHODS

In this prospective randomised, interventional trial, 40 patients scheduled for elective coronary artery bypass grafting were randomly assigned to undergo either on-pump or OPCAB-surgery, if both techniques were feasible for the single patient. Clinical data, myocardial damage assessed by myocard specific creatine kinase isoenzyme (CK-MB), circulating whole blood levels of selenium, oxidative stress assessed by asymmetric dimethylarginine (ADMA) levels, antioxidant capacity determined by glutathionperoxidase (GPx) levels and perioperative inflammation represented by interleukin-6 (IL-6) levels were measured at predefined perioperative time points.

RESULTS

At end of surgery, both groups showed a comparable decrease of circulating selenium concentrations. Likewise, levels of oxidative stress and IL-6 were comparable in both groups. Selenium levels correlated with antioxidant capacity (GPx: r = 0.720; p<0.001) and showed a negative correlation to myocardial damage (CK-MB: r =  -0.571, p<0.001). Low postoperative selenium levels had a high predictive value for the occurrence of any postoperative complication.

CONCLUSIONS

OPCAB surgery is not associated with less oxidative stress and a better preservation of the circulating selenium pool than on-pump surgery. Low postoperative selenium levels are predictive for the development of complications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01409057.

Blood selenium and glutathione peroxidases in miscarriage

OBJECTIVE

To investigate the selenium glutathione and glutathione peroxidase (glutathione-Px) levels in blood in women who experience miscarriage.

DESIGN

An observational study.

PARTICIPANTS

Forty women with miscarriage occurring in the first and second trimesters.

METHODS

Concentrations were measured in whole blood and plasma. Glutathione was measured in red cells and glutathione-Px activity was measured in the red cells and plasma. The results were compared with 36 women in the same period of viable pregnancy and 28 age-matched, healthy, non-pregnant controls.

RESULTS

The selenium concentrations in whole blood and plasma of women following abortion were the same as in viable pregnancy, but were significantly lower compared with controls. The glutathione levels were significantly higher in women with miscarriage compared with viable pregnancies and with non-pregnant women. Red cell and plasma glutathione-Px activities of women who had had a miscarriage were significantly lower than in both normal pregnancies and the control group.

CONCLUSION

The decreased activities of the antioxidant enzymes, red cell and plasma glutathione-Px, may play an important role in the aetrology of spontaneous abortion.