Comparison of Low Yield Cigarettes in African Americans vs. Whites
Condition: Cigarette Smoking
Study type: Interventional
Phase: Phase 1

Summary: 
      The investigators' general hypothesis is that African-Americans (AAs) smoke more for positive
      reinforcement from nicotine with a "peak-seeking" pattern of smoking (smoking individual
      cigarettes more intensively with greater intake of nicotine and tobacco smoke toxins), while
      whites smoke more for negative reinforcement with a "trough-maintaining" pattern (avoiding
      withdrawal by maintaining more consistent nicotine levels throughout the day by means of a
      more regular smoking pattern). We, the investigators, believe that these patterns are linked
      to identifiable racial differences in nicotine pharmacology.

      For this study we hypothesize that if AAs behave more like nicotine "peak-seeker" while
      whites behave more like nicotine "trough-maintainers", that AAs will respond to switching
      from regular to low nicotine yield commercial cigarettes by smoking each cigarette relatively
      more intensively with a relatively smaller increase in daily cigarette consumption
      (cigarettes per day or CPD) as compared to whites.
    

Detailed description: 
      Several lines of evidence indicate that AAs are more highly addicted to cigarette smoking
      than are whites. AAs are more likely to smoke their first cigarette within 10 minutes of
      awakening, an indicator of the severity of the dependence. They are more likely to want to
      quit smoking and are more likely to try to quit (attempts lasting at least 24 hours, but are
      significantly less likely than whites to be successful abstainers at one year. The quit ratio
      (former smokers/ever smokers) was recently reported to be 37.3% in AAs compared to 51% for
      whites (2).

      NICOTINE REGULATION IN AAS AND WHITES: In general smokers regulate (titrate) their smoking to
      take in about the same amount of nicotine from day to day. This behavior is well demonstrated
      in studies of smokers smoking commercial cigarettes of differing yields, showing that smokers
      take in similar amounts of nicotine from high- and low-yield cigarettes. NCI MONOGRAPH 13
      summarized the data on nicotine and low yield cigarettes and concluded that low yield
      cigarettes presented the same health risks as high yield cigarettes (12). However, most or
      all of the research on nicotine titration appears to have been done primarily in white
      smokers.

      We believe that nicotine titration patterns will differ in AAs compared to whites, based on
      the hypothesis that AAs smoke more for the positive reinforcing effects of individual
      cigarettes, while whites smoke more to maintain a consistent level of nicotine. We predict
      that the response to switching from regular to low yield cigarettes in AAs will differ in
      that they will try to take in more nicotine per cigarette by smoking more intensively, but
      will be less likely to try to regulate their total daily intake of nicotine compared to
      whites.

      Melanin: A recent study (14) showed that levels of facultative melanin (includes both
      genetically and exposure influenced melanin) in the skin are significantly and positively
      related to cigarettes per day, the Fagerstrom score, and cotinine levels. By measuring
      melanin levels in our own study subjects, we will be able to determine if there is a
      relationship between melanin levels and nicotine pharmacokinetics.

      This is a non-randomized, non-blinded, two treatment arm crossover study with an oral
      nicotine and cotinine pharmacokinetic study. Cigarettes will be supplied for both treatment
      arms and subjects will smoke ad libitum. During the first arm, the subject will smoke their
      "usual" cigarettes and also undergo an oral pharmacokinetics protocol. During the second arm,
      subjects will smoke a commercial cigarette with a machine-determined nicotine yield of
      approximately 50% of their "usual" brand.

      Blood and urine samples will be collected throughout the study and analyzed by our usual
      methods.
    

Intervention name(s): Deuterated nicotine and cotinine
Intervention type(s): Drug
Intervention description(s): used as a marker for pharmacokinetic studies
Intervention MeSH terms: Nicotine
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Smoking; nicotine