Nicotine and acute stress: effects of nicotine versus nicotine withdrawal on stress-induced hemoconcentration and cardiovascular reactivity.

This study was designed to assess the effects of nicotine and nicotine withdrawal on stress-induced hemoconcentration and cardiovascular reactivity during acute stress in smokers. Forty-six smokers (>or=10 cigarettes per day) were tested twice, once while wearing a 21 mg nicotine patch for 12h and once while wearing a placebo patch (nicotine withdrawal). Calculated plasma volume, hemoglobin, hematocrit, HR, SBP, DBP, cardiac output, stroke volume, and total peripheral resistance were assessed during a 10-min baseline period, 6-min Paced Auditory Serial-Addition Task (PASAT), and a 2-min cold pressor (CP). No differences between conditions were found for any of the hematological measurements. Participants demonstrated greater HR and SBP increases to the PASAT during the nicotine withdrawal condition. For CP, participants showed greater HR and DBP increases and SV decreases during the nicotine withdrawal condition. Data from affective state ratings indicated that participants reported more negative affect during the psychological challenges during nicotine withdrawal conditions. Negative affective state may further lead to enhanced cardiovascular reactivity. These results demonstrate that although nicotine and nicotine withdrawal significantly have differential effects on cardiovascular functioning, the same differential condition effects do not appear to exist for stress-induced hemoconcentration.