The short-term effect of water-pipe smoking on the baroreflex control of heart rate in normotensives.

UNLABELLED: The aim of this study is to analyse the acute effect of water-pipe smoking on heart rate, blood pressure and the baroreflex control of heart rate. SUBJECTS AND METHODS: Non-invasive continuous methods were used for investigating inter-beat interval (IBI; ms), systolic blood pressure (SBP; mm Hg), diastolic blood pressure (DBP; mm Hg), pulse pressure (PP; mm Hg), mean blood pressure (MBP; mm Hg); baroreflex sensitivity in ms/mm Hg (BRS) and baroreflex sensitivity in Hz/mm Hg (BRSf), were determined by spectral analysis, in 20 normotensive volunteers age of 27+/-6 years (mean+/-S.D.) who served as their own control. The measurements were taken twice. The first measurement was taken before the water-pipe smoking session (this is after >12 h of smoking cessation with a complete stopping of alcohol, coffee or tea consumption). The second measurement was taken during a 5 min period immediately after that session. (In the smoking session the volunteer smokes 5 g Maassel (fruit flavoured tobacco) for a period of 45 min).
RESULTS: The inter-beat interval decreased (846+/-100 to 709+/-109 ms, p=0.0003), SBP increased (110+/-13 to 123+/-12 mm Hg, p=0.004), DBP increased (67+/-11 to 81+/-11 mm Hg, p=0.0002), PP decreased (43+/-10 to 41+/-9 mm Hg, p=0.46 ns), MBP increased (82+/-10 to 95+/-11 mm Hg, p=0.0001), BRS decreased (9.16+/-4 to 5.67+/-3 ms/mm Hg, p=0.003) and BRSf (0.013+/-0.005 to 0.011+/-0.004 Hz/mm Hg, p=0.3 ns).
CONCLUSIONS: Water-pipe smoking induced a high increase in heart rate, SBP, DBP, MBP and markedly impaired BRS. All of those markers are known as risk factors in cardiovascular diseases, hence it is concluded that water-pipe smoking is not as harmless as is thought.