Effects of Smoking on HR Circadian Rhythm in Hypertensive and Non Hypertensive Subjects

Clinical parameters as Blood Pressure and Heart Rate (HR) are influenced by hypertension and smoking. To evaluate how these risk factors influence HR, usually punctual or mean evaluation of these signals on daytime or nighttime are made. However, since HR has a circadian behavior, changing during 24h, a punctual description represents only a rough approximation of this comportment. In this study, we analyzed the influence of smoking and hypertension on the circadian rhythm of HR with a standard temporal resolution. Data coming from 618 hypertensive/non-hypertensive, smokers/non-smokers subjects were recorded using a Holter BP monitor. Results confirmed significant higher values of HR during day and nighttime in smokers than in non-smokers also highlighting different velocity of HR linear changes in three periods of the 24h (daytime, nighttime, early morning).