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

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.