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Haemodynamic responses to tobacco smoke inhalation in male adolescents in Lusaka, Zambia.

Background
Tobacco smoke causes changes in the levels of catecholamines in the blood. This leads to an increase in blood pressure and heart rate. This is due to nicotine which has also been noted to cause a decrease in vasodilatory activities leading to an increase in both the blood pressure and heart rate.


Aim
To determine the acute effects of tobacco smoke on haemodynamics in black male adolescents in Lusaka, Zambia.


Study design
This was an observational study done at the University of Zambia School of Medicine Cardiovascular Research Laboratory in the month of December, 2014.


Methodology
Twenty-two (22) black, male-adolescent (age range 19-25 years), active-smokers, consented to participate in the study. The Diasys Ambulatory Blood Pressure Monitoring system (Novacor, France) was used to obtain the Systolic and Diastolic blood pressures (SBP and DBP) and the heart rate. These were obtained 15 minutes before smoking at 5 minute intervals and averaged to obtain the baseline, during the 15 minutes of smoking and on immediate cessation of smoking and thereafter every 15 minutes up to an hour after smoking.


Results
There was a significant rise in SBP (mmHg) during smoking (127.9 ± 13.80 mmHg) from baseline values (113.5 ± 13.15 mmHg) (P = .00). It took 30 minutes for the SBP to return to baseline after cessation of smoking. DBP (mmHg) also increased from baseline (79.5 ± 8.79 mmHg) to 85.6 ± 10.92 mmHg during smoking (P = .01). It returned to baseline values immediately after cessation of smoking. The heart rate (bpm) was also noted to significantly increase during smoking (95.2 ± 16.72 bpm) from the values noted before smoking (74.3 ± 13.75 bpm) (P = .05). The mean value for heart rate returned to baseline value by the 15th minute of recovery.


Conclusion
The present study demonstrates that smoking may be the cause for the acute increases in SBP, DBP and heart rate in smokers. The smoking caused significant increases in all the haemodynamic indices considered in this study within 15 minutes. Both SBP and DBP increase are indices for stroke and coronary heart disease respectively. The effect of increased SBP was noted to last for 30 minutes while DBP returned to baseline immediately after smoking. A significant increase in heart rate was also noted in the study.