The Impact of Early Pregnancy and Exposure to Tobacco Smoke on Blood Antioxidant Status and Copper, Zinc, Cadmium Concentration—A Pilot Study

Abstract

The aim of the study was to evaluate the impact of early pregnancy and exposure to tobacco smoke on antioxidant status and copper, zinc, and cadmium concentrations in the blood of non-smoking and smoking, as well as non-pregnant or pregnant women. The study included 213 women. More specifically, 150 women in first trimester of pregnancy and 63 non-pregnant women. Women were divided into subgroups according to exposure to tobacco smoke. Pregnancy significant influences higher copper and lower zinc concentration in the serum, whereas exposure to tobacco smoke during pregnancy is mainly associated with an elevation in cadmium and zinc concentration. It seems that metallothionein, superoxide dismutase, and glutathione peroxidase are the important antioxidants during early pregnancy, when exposure to tobacco smoke occurs, whereas the pregnancy itself is associated with a higher concentration of metallothionein and activity of catalase. Both pregnancy in the first trimester and exposure to tobacco smoke decrease glutathione concentration. In addition, active and passive maternal smoking have a similarly negative effect on antioxidant status in the first trimester. Early pregnancy as well as exposure to tobacco smoke is associated with significant alteration in antioxidant status and copper, zinc, and cadmium concentration. Due to a small number of smoking subjects (11 cases of non-pregnant, active smokers and 14 pregnant active smokers), the obtained results should be treated as a pilot, and this should be considered for future studies.

Influence of Oxidative Stress Generated by Smoking during Pregnancy on Glutathione Status in Mother-Newborn Pairs

“…To the best of our knowledge, this is the first report to describe the effect of smoke on oxidized glutathione levels in the blood of pregnant women, which in the physiological stage accounts for less than 1–2% of the total GSH pool and increases under conditions of oxidative stress [ 15 , 17 ]. We observed higher levels of GSSG and slightly higher levels of GPx in smokers compared with non-smokers, while other authors showed significantly higher activity of this enzyme [ 9 , 19 , 20 ]. These differences may be due to the fact that we determined the level of an extracellular form of glutathione peroxidase (GPx-3), which is most abundant in plasma, while others tested total GPx activity [ 36 , 37 ].…”

“…In pregnant tobacco smokers, maintaining redox homeostasis seems to be particularly important in the context of the well-being of both mother and child [ 9 , 10 ]. Tobacco smoke contains a number of toxic compounds, including oxidants and FRs, which are responsible for the intensification of oxidative stress and the occurrence of pathological changes in the body.…”

“…Our research has confirmed the results of other authors who showed no differences between the levels of reduced glutathione in the blood of pregnant smokers and non-smokers [ 20 , 35 ]. There are also reports of a negative effect of tobacco smoke on the levels of this compound during gestation [ 9 , 21 ]. However, in one case [ 21 ], a study was conducted in smoking pregnant women with intrauterine growth restriction, which may be associated with increased oxygen stress and increased consumption of antioxidant systems.…”

“…However, in one case [ 21 ], a study was conducted in smoking pregnant women with intrauterine growth restriction, which may be associated with increased oxygen stress and increased consumption of antioxidant systems. In another study [ 9 ], GSH levels were measured in whole blood in a group of active smokers during the first trimester of pregnancy. Gould et al [ 33 ] reported that short-term exposure decreased GSH levels whereas our study was carried out at the end of pregnancy in patients who smoked an average of 7.9 years before conception, indicating long-term exposure to tobacco smoke.…”

“…[ 1 ]. In contrast, exposure to tobacco smoke during pregnancy may impair the defense activity of both antioxidant enzymes and small-molecule non-enzymatic antioxidants [ 9 , 10 , 11 ]. We have previous evidence that oxidative marker levels (e.g., TOC—total oxidant capacity, MDA—malondialdehyde, ox-LDL—oxidized low-density lipoprotein) were higher and antioxidant concentrations (e.g., TAC—total antioxidant capacity, vitamins A, E, and adiponectin) were lower in smoking pregnant women than in non-smoking ones [ 12 , 13 ].…”