High cadmium / zinc ratio in cigarette smokers: potential implications as a biomarker of risk of prostate cancer.

Abstract

SummaryTobacco smoke may be one of the most common sources of cadmium (Cd) in the general population, particularly in the rising population of smokers in developing countries. Although a relationship between both cigarette smoking and environmental Cd contamination with prostate cancer exist, the mechanisms are unclear. Most prospective cohort studies found a positive association between current smoking and a fatal cancer of the prostate. We investigated the interaction between zinc and cadmium and the potential risk of prostate cancer in smokers. Serum cadmium level was significantly (P<0.001) higher in smokers compared with non-smokers, the level in smokers was three-fold that in non-smokers. In contrast zinc was significantly (P<0.001) reduced in smokers compared with non-smokers. Unlike Zn, Cu was significantly (P<0.05) higher in smokers than in nonsmokers. Iron (Fe) though higher in smokers was not significantly different. Zinc: cadmium ratio was very significantly (P<0.001) reduced, implying high cadmium: zinc ratio. This ratio was 4.5-fold the level in nonsmokers. Total protein, albumin and total globulin levels were all significantly (P<0.001) reduced in smokers compared with non-smokers respectively. Potassium (K + ) was significantly (P<0.05) higher in smokers than in non-smokers. Magnesium (Mg) was significantly (p<0.01) reduced in smokers compared to non-smokers. Altered Zn status culminating in high Cd:Zn ratio appears the central factor in smokers; leading to oxidative stress, DNA damage, mutation, impaired DNA repair, P 53 expression, angiogenic effect of Cu and impaired vitamin A metabolism. These converge in the risk of the carcinogenic process, suggesting high Cd: Zn ratio as the critical determinant of the risk of prostate cancer in smokers and possibly a biomarker of susceptibility to this environmental disease.

Association between Smoking and Anthropometric Characteristics, Biochemical Markers, and Dietary Intake of Pakistani Male Adult Population

“…29 Our results on zinc status of smokers and non-smokers correspond to those of Uz, et al 45 and Anetor, et al 46 who also reported significantly lower serum zinc levels in smokers in comparison to non-smokers. The lower serum zinc concentration of smokers compared to non-smokers could also be due to the influence of cadmium, an essential constituent of cigarette smoke that may act as an antagonist to zinc bioavailability.…”

Human CYP2A6 is regulated by nuclear factor-erythroid 2 related factor 2

“…Cigarette smoking is known to cause oxidative stress, which activates Nrf2 [25,26]. In addition, tobacco is a substantial source of cadmium, supported by the fact that the serum cadmium level of smokers is 3 folds higher than that of non-smokers [27]. Therefore, it is surmised that the CYP2A6 expression level might be higher in smokers than in non-smokers, although there is no report comparing the expression level of hepatic CYP2A6 protein in smokers versus that in non-smokers.…”

An Update on Occupation and Prostate Cancer

“…This is seen as a cause and effect result concerning Arsenic. Anetor et al, (2008 An increase in 1 micro g/g creatinine cadmium exposure was associated with a 35% increase in PSA level.…”

“…Although Li et al (2011) did suggest there was a dose response relationship with carcinogenesis at other organs. Other studies have examined the zinc: cadmium ratios (Drasch et al, 2005, Anetor et al, 2008 and the possibility that reduced selenium uptakes may have a more pronounced effect in the presence of high cadmium levels. Lee et al (2009) No length of employment In addition to the qualitative review of individual studies, a meta-analysis was performed to combine data from individual cohort studies of petroleum workers.…”