Examining racial differences in smoking outcomes among smokers enrolled in an intravenous nicotine infusion study

Large racial disparities exist in the prevention and treatment of smoking-related diseases, and minoritized populations carry a heavier burden of smoking-related morbidity and mortality. To date, most studies investigating smoking-related illnesses have been conducted in samples in which the majority, or totality, self-identified as White or Caucasian. While Black individuals who smoke tend to have a lower rate of nicotine clearance, in part due to the use of mentholated cigarettes, less is known about how slower clearance affects their acute subjective and physiologic responses in response to either overnight abstinence or subsequent nicotine administration. This study aimed to investigate differences between the experiences of Black and White individuals who smoke across these outcomes after a period of short-term abstinence and after IV nicotine infusion.

The study included 206 smokers (N = 103 Black, N = 103 White, by self-report). The study investigated self-report, physiological, and biochemical smoking-related outcomes following confirmed overnight abstinence followed by IV nicotine infusion. The outcome measures were separately analyzed with repeated-measures mixed-models.

Black individuals had lower rates of nicotine clearance and were more likely to smoke mentholated cigarettes than White individuals. Despite these differences, no differences in withdrawal, cravings, or physiological outcomes were observed between the two groups. There were some trends toward differences in subjective experiences, in that an interaction with trend level significance between race and dose was observed for negative subjective drug effects, with White smokers trending towards endorsing higher levels of negative affect after abstinence and nicotine infusion. We also observed that Black individuals trended towards experiencing more negative drug effects in response to initial nicotine delivery than to saline, whereas White individuals had no differences in negative drug effects across saline or nicotine doses.

Despite slower nicotine clearance, Black participants exhibited withdrawal and urges to smoke as severe as White participants, and did not have blunted physiological responses to overnight abstinence or administration of nicotine, which were contrary to our hypotheses. Our findings suggest minimal differences across races in the acute pharmacologic effects of nicotine. We observed trend-level differences in subjective and affective responses to nicotine. Greater insight into these differences may lead to improved prevention and treatment strategies for smoking-related illnesses for Black individuals who smoke.