Sex differences in effects of cigarette smoking and 24-hr abstinence on plasma arginine vasopressin.

The present study examined plasma arginine vasopressin (AVP) levels in 18 smokers (10 men, 8 women) and in 22 non-smokers (12 men, 10 women). Non-smokers came to the laboratory once, whereas smokers came twice: while smoking freely and following 24-hr abstinence. Plasma was collected for AVP assessment; salivary cotinine and expired carbon monoxide levels confirmed smoking status. Among non-smokers, men had higher AVP levels than did women (p<0.05). Among smokers, however, women displayed higher AVP levels than did men both while smoking and following abstinence (p's<0.05). Among men, smoking resulted in lower AVP levels compared to non-smoking men. In contrast, women who smoked displayed higher AVP levels compared to their non-smoking counterparts. AVP levels were not affected by 24-hr abstinence among smokers, regardless of sex, which suggests that dysregulation in AVP levels in tobacco smokers continues even following 24-hr abstinence. Findings are consistent with previous reports of elevated Th1/Th2 immune function among female smokers compared to male smokers and to male and female non-smokers. Data suggest sex-dependent AVP changes during smoking that could contribute to negative impact of smoking on cardiovascular health.