Biomarkers of exposure and potential harm in adult smokers of 3–7 mg tar yield (Federal Trade Commission) cigarettes and in adult non-smokers

Abstract

The paper reports levels of 24-h urine nicotine and five of its major metabolites (expressed as nicotine-equivalents) and blood carboxyhaemoglobin as biomarkers of exposure to particulate- and gas-phase cigarette smoke, respectively, from an exploratory pilot study of adult smokers of 3.0–6.9 mg tar delivery (Federal Trade Commission (FTC) method) cigarettes. On multiple occasions over 6 weeks, blood high-sensitivity C-reactive protein (hs-CRP), fibrinogen, HDL- and LDL-cholesterol, and 24-h urine 8-epi-prostaglandin F_2α (8-epi-PGF_2α) and 11-dehydro-thromboxane B₂ (11-dehydro-TxB₂) were also evaluated as biomarkers of potential harm. All the biomarkers examined, except for LDL-cholesterol, discriminated with high sensitivity and specificity between adult smokers and non-smokers overall. Except for HDL-cholesterol, all biomarker medians were greater in adult smokers than in non-smokers: urine nicotine-equivalents 64.514 versus<0.034 nmol mg⁻¹ creatinine (p<0.001), carboxyhaemoglobin 4.0 versus 0.4% saturation (p<0.001), hs-CRP 0.27 versus 0.12 mg dl⁻¹ (p=0.05), fibrinogen 292 versus 248 mg dl⁻¹ (p<0.001), HDL-cholesterol 46 versus 53 mg dl⁻¹ (p=0.003), LDL-cholesterol 119 versus 109 mg dl⁻¹ (p=0.18), urine 8-epi-PGF_2α 1935 versus 1034 pg mg⁻¹ creatinine (p<0.001) and urine 11-dehydro-TxB₂ 973 versus 710 pg mg⁻¹ creatinine (p<0.001). All the biomarkers of exposure and most of the biomarkers of potential harm showed no time of sampling (by visit week) effect.