Does smoking reduction result in reduction of biomarkers associated with harm? A pilot study using a nicotine inhaler.

The aim of the study was to determine if smoking reduction using a nicotine inhaler in heavy cigarette smokers who wanted to reduce but not stop smoking results in decreased levels of known biomarkers of harm. The study design was a one-sample within-subject comparative open-label study of 23 (10 male and 13 female) subjects using a nicotine inhaler to reduce smoking, with follow-up at 24 weeks. A structured protocol was used with a smoking-reduction schedule from 40 or more cigarettes per day to 10 cigarettes per day by week 9. Behavioral counseling was provided by a research assistant and ad lib use of the nicotine inhaler for 12 weeks was permitted. Blood thiocyanate, cotinine, 4-aminobiphenyl hemoglobin adducts; urine NNAL and NNAL-glucuronide; and expired air carbon monoxide were measured. On average, the subjects were able to reduce their smoking by over 50% at week 12, but only two were able to reduce to 10 cigarettes per day. The reported reduction in smoking was not associated with a consistent reduction in the biomarkers. There was no reduction in the NNAL, 4-aminobiphenyl hemoglobin adducts nor carbon monoxide levels of expired air. There was a significant reduction of NNAL-glucuronide and the sum of NNAL and NNAL-glucuronide but only at week 24. Thiocyanate levels increased. Before widely promoting harm reduction as a treatment strategy for heavy smokers, more research needs to be performed to prove conclusively that such smokers who want to reduce but not stop can actually reduce and maintain their smoking rate at a level which is likely to reduce harm. It also needs to be determined whether a reduction in the smoking rate translates into reduction of harm. At the present, for heavy smokers, an abstinence approach seems to be more scientifically sound.