Urinary nicotine metabolites: usefulness as biomarkers of smoking status

Aims Nicotine is metabolised to cotinine (COT) and further to trans-3&#039;-hydroxycotinine (HCOT) by the cytochrome P450 CYP2A6 enzyme. It has been demonstrated that the ratio of HCOT to COT is an index of CYP2A6 activity, thus a marker of nicotine metabolism, with higher ratios indicating faster metabolism. Evidence shows that the ratio, in urine, saliva or plasma, could predict responses to smoking cessation medication and guide pharmacotherapy. Since the literature about the association between this ratio and the cigarettes smoked per day (cpd) is not uniform, our aim was to investigate this relationship using urine samples from smoking females living in Romania, Portugal, Belgium and Slovenia. Methods Urine samples from mothers (aged up to 45 years) who participated in the EU project DEMOCOPHES(LIFE09/ENV/BE/00410) were used. The concentrations of COT and HCOT were determined by online-SPE UPLC MS/MS and subsequently normalised to creatinine content. The amount of cpd was available from the questionnaires. Results and conclusions As expected, a strong positive correlation between COT and HCOT levels was found. Regarding the association between HCOT/COT ratio and cpd, no correlation was observed when the data were globally considered. We confirmed that the correlation between cpd and cotinine differed according to the HCOT/COT ratio: higher correlations for slow metabolizers (low ratio) and almost no correlation for fast metabolizers (high ratio). A new analytical strategy is in progress to fully explore the usefulness of this ratio as biomarker of cigarette consumption.</p

Exposure determinants of cadmium in European mothers and their children

The metal cadmium (Cd) is a widespread environmental pollutant with documented adverse effects on the kidneys and bones from long-term environmental exposure, but with insufficiently elucidated public health consequences such as risk of cardiovascular disease, hormone-related cancer in adults and developmental effects in children. This study is the first pan-European human biomonitoring project that succeeded in performing harmonized measurements of Cd in urine in a comparable way in mother-child couples from 16 European countries. The aim of the study was to evaluate the overall Cd exposure and significant determinants of Cd exposure. A study population of 1632 women (24-52 years of age), and 1689 children (5-12 years of age), from 32 rural and urban areas, was examined within a core period of 6 months in 2011-2012. Women were stratified as smokers and non-smokers. As expected, smoking mothers had higher geometric mean (gm) urinary cadmium (UCd; 0.24microg/g crea; n=360) than non-smoking mothers (gm 0.18microg/g crea; n=1272; p&lt;0.0001), and children had lower UCd (gm 0.065microg/g crea; n=1689) than their mothers at the country level. Non-smoking women exposed to environmental tobacco smoke (ETS) at home had 14% (95% CI 1-28%) higher UCd than those who were not exposed to ETS at home (p=0.04). No influence of ETS at home or other places on UCd levels was detected in children. Smoking women with primary education as the highest educational level of the household had 48% (95% CI 18-86%) higher UCd than those with tertiary education (p=0.0008). The same observation was seen in non-smoking women and in children; however they were not statistically significant. In children, living in a rural area was associated with 7% (95% CI 1-13%) higher UCd (p=0.03) compared to living in an urban area. Children, 9-12 years had 7% (95% CI 1-13%) higher UCd (p=0.04) than children 5-8 years. About 1% of the mothers, and 0.06% of the children, exceeded the tolerable weekly intake (TWI) appointed by EFSA, corresponding to 1.0microgCd/g crea in urine. Poland had the highest UCd in comparison between the 16 countries, while Denmark had the lowest. Whether the differences between countries are related to differences in the degree of environmental Cd contamination or to differences in lifestyle, socioeconomic status or dietary patterns is not clear</p