ABSTRACT
To evaluate the effect of smoking habits on sleep, data from 1492 adults referred to the Sleep Institute were accessed and divided into 3 categories of smoking status: current, former and non-smokers. Categories of pack-years (<15 and greater than or equal to 15) defined smoking severity. The association of smoking status and smoking severity with sleep was analyzed for sleep parameters, especially apnea and hypopnea index (AHI) greater than or equal to 5, more than 5 percent of total sleep time (TST) spent with oxyhemoglobin saturation (SaO2) <90 percent, and arousal index. The arousal index was higher among current (21 plus or minus 17) and former smokers (20 plus or minus 17) than non-smokers (17 plus or minus 15; P < 0.04). Former smokers had a higher percent of TST at SaO2 <90 percent than non-smokers (9 more less 18 vs 6 more less 13; P < 0.04). Former smokers with pack-years greater than or equal to 15 compared to <15 exhibited higher AHI (22 plus or minus 24 vs 16 plus or minus 21; P < 0.05) and arousal index (22 plus or minus 19 vs 18 plus or minus 15; P < 0.05). Current smokers with pack-years greater than or equal to 15 compared to <15 exhibited higher arousal index (23 plus or minus 18 vs 18 plus or minus 16; P < 0.05) and percent of TST at SaO2 <90 percent (11 plus or minus 17 vs 6 more less 13; P < 0.05). Smoking status and pack-years were not associated with AHI greater than or equal to 5 on logistic regression analysis, but current smokers with pack-years greater than or equal to 15 were 1.9 times more likely to spend more than 5 percent of TST at SaO2 <90 percent than non-smokers (95 percentCI = 1.21-2.97; P = 0.005). The variability of arousal index was influenced by gender, AHI and current smokers with pack-years greater than or equal to 15 (all P < 0.01). Smoking habits seem to be associated with arousal and oxyhemoglobin desaturation during sleep, but not with AHI. The effect was more pronounced in current than former smokers.