The Alterations Of Circadian Rhythms Of Sleep-wake, Rest-activity And The Relationship To Blood Pressure And Heart Rate In Hypertensive Patients

Objective: To investigate the alterations in circadian sleep-wake and rest-activity rhythms in hypertensive patients, and if the circadian rhythms of sleep-wake and rest-activity differ in dippers and nondippers types of the hypertension. We also aimed to study how is the relationship between the electronically monitored physical activity and the blood pressure and heart rate in hypertensive subjects.Methods: Forty-two hypertensive patients and twenty-one healthy volunteers were recruited in this study. They wore an ambulatory blood pressure monitor and a wrist actigraph simultaneously to record circadian sleep-wake and rest-activity rhythms for two days. The blood pressure and heart rate were measured every thirty minutes for twenty-four hours. Each average activity for 5 min was determined before each valid blood pressure reading. Activity was correlated with blood pressure and heart rate using Pearson's correlation coefficient in each patient individually and overall group. Results A significant decreased M10(maximum 10 hours activity) and AMP (amplitude) and increased L5(activity in low activity 5 hours) were found in hypertensive patients. In addition, SE (sleep efficiency) was significantly decreased, WB (number of wake bouts) and FI (fragmentation Index) was significantly increased in these subjects. We also found that L5, WB and FI were significantly increased in hypertensive nondippers, SE was significantly decreased in these subjects. For individual patients, positive correlation was found between activity levels and blood pressure and heart rate to most patients, but there was marked variation in the degree of correlation. Strong positive correlation was found between group day and 24-h averageactivity and blood pressure and heart rate.Conclusion: The data derived from actigraph showed a significant alteration ofcircadian rhythms of sleep-wake and rest-activity in hypertensive patients andhypertensive nondippers. These findings also indicate that physical activity has greatinfluence on blood pressure and heart rate.