Heart rate variability increases with reductions in cigarette smoke exposure after 3 days.
BACKGROUND
Smoking has been shown to influence the tone of the autonomic nervous system as reflected by heart rate variability (HRV). To date, no information is available as to whether 24-hour HRV might differentiate users of different tobacco products.


OBJECTIVE
To assess the differences in HRV derived from the 24-hour electrocardiogram (ECG) following the use of 2 tobacco products of potentially different exposures.


METHODS
Thirty adult Caucasian male smokers (mean age: 42.8 + 5.7 years) smoking 20 to 40 cigarettes/ day were randomized in a 3-way crossover study design to either smoke a conventional cigarette (CC, tar: 11 mg, Nic: 0.8 mg), to use the Electrically Heated Cigarette Smoking System (EHCSS: tar: 5 mg, Nic: 0.3 mg, according to the Federal Trade Commission [FTC]), or to stop smoking (NS) for 3 days each. The 24 hours ECGs were recorded during the last 24 hours of each exposure period.


RESULTS
A 24-hour ECG showed highest mean values for standard deviation of all normal-to-normal heart beat (NN) intervals (SDNN), standard deviation of all 5-minute averaged NN intervals in a 24-hour period (SDANN), mean of the standard deviations of the NN intervals calculated from all 5-minute segments in a 24-hour period (SDNNI), percentage (P) of all NN intervals that differ by 50 milliseconds of all NN (PNN50%), the square root of the mean of all squared differences between adjacent NN intervals in 24-hour period (RMSSD), and total number of all NN intervals divided by the height of the histogram of all NN intervals measured on a discrete scale with bins of 7 x 8125 ms (1/128 seconds; HRVTI) when participants stopped smoking followed by the use of the reduced exposure product and CC.


CONCLUSIONS
Heart rate variability tended to increase with reduced smoke exposure.
Munjal
Sagar
S
Philip Morris USA, Richmond, Virginia, USA.
Koval
Tamara
T
Muhammad
Raheema
R
Jin
Yan
Y
Demmel
Valentin
V
Roethig
Hans J
HJ
Mendes
Paul
P
Unverdorben
Martin
M
D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects*; D018592:Cross-Over Studies; D015716:Electrocardiography, Ambulatory; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D012907:Smoking / Q000009:adverse effects*; D016540:Smoking Cessation; D013997:Time Factors
D018722:Nicotinic Agonists; D009538:Nicotine