Cigarette smoking causes an acute increase in blood pressure and heart rate and has been found to be associated with malignant hypertension (HT). A significant flux of toxic metals among other toxins reaches the lungs through smoking. In the present study, the relationship between essential (zinc and selenium) and toxic element (TE; cadmium and mercury) and HT incidence in smoker and nonsmoker population living in Dublin, Ireland was investigated. The zinc (Zn), selenium (Se), cadmium (Cd) and mercury (Hg) were determined in biological (scalp hair and blood) samples of smoker and nonsmoker hypertensive patients. For comparison purposes, healthy age- and sex-matched subjects as referents residing in the same city were also selected. The different brands of cigarette consumed by the studied population were also analyzed for Cd and Hg. The concentrations of essential trace and TEs in all studied samples were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials (CRMs). The recovery of all the studied elements was found to be in the range of 96.4-99.7% of certified values of CRMs. The filler tobacco of different branded cigarettes contains Hg and Cd concentrations in the range of 9.55-12.4 ng and 1.70-2.12 μg per cigarette, respectively. The results of this study showed that the mean values of Cd and Hg were significantly higher in scalp hair and blood samples of hypertensive patients as compared with healthy controls, whereas Zn and Se concentrations were found to be lower in hypertensive patients, the difference was significant in the case of smoker patients (P<0.001). The levels of both TEs were 2-3-folds higher in scalp hair and blood samples of nonhypertensive smoker subjects as compared with nonsmoker controls. It was observed that exposure of TEs via cigarette smoking may be synergistic with other risk factors associated with HT.
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